Technical Field [0001] Various embodiments generally relate to a dual-input transmission assembly and a powertrain having the dual-input transmission assembly for a vehicle. In particular, various embodiments generally relate to a dual-input transmission assembly for a vehicle capable of land and aerial transportation (i.e. flying car), and a powertrain for the vehicle capable of land and aerial transportation.

Background

[0002] In recent years, various models of flying cars have been commercialized in the market. For example, the PAL-V flying car features a dual engine configuration with dual drivetrain, using one engine for driving on the road and one for flying in the air. As another example, the Aeromobil flying car feature a generator/engine to run two separate mode via one switching mechanism switchable between powering the propeller for flight and powering a pair of electric motors for driving. However, if the switching mechanism fails, there is no alternative ways to operate the flying car. As can be seen, these flying cars either have separate powertrain for driving and flying, or have one generator/engine switchable between driving separate drivetrain for flying and driving. Thus, they generally have multiple drivetrain taking up excess weight and space, as well as a lack of backup in case of propulsion failure for land and air travel.

[0003] Accordingly, there is a need for a more effective powertrain solution without compromising performance and/or safety for the vehicle so as to address the above issues.

Summary

[0004] According to various embodiments, there is provided a dual input transmission assembly. The dual input transmission assembly includes a primary internal ring gear rotatable about a central rotational axis extending though a centre of the primary internal ring gear; a transfer internal ring gear arranged side-by-side to the primary internal ring gear along the central rotational axis in a coaxial manner and rotatable about the central rotational axis; a set of planetary gears, each planetary gear extending axially from within the primary internal ring gear to within the transfer internal ring gear in a manner parallel to the central rotational axis, each planetary gear having a first axial portion in engagement with the primary internal ring gear and a second axial portion in engagement with the transfer internal ring gear; a planet carrier to hold the set of planetary gears, the planet carrier being rotatable about the central rotational axis so as to cause the set of planetary gears to revolve around the central rotational axis, wherein each planetary gear is rotatably mounted to the planet carrier so as to be rotatable about its axis of rotation; a primary sun gear in mesh engagement with the first axial portions of the set of planetary gears, the primary sun gear being coaxial with the primary internal ring gear and rotatable about the central rotational axis; and a planet carrier brake to selectively engage the planet carrier so as to lock the planet carrier from rotating about the central rotational axis. A rotation of the transfer internal ring gear is generated by providing a rotary input to the primary sun gear with the planet carrier brake in engagement with the planet carrier, or a rotary input to the primary internal ring gear, or a rotary input to the primary sun gear together with a reverse rotary input to the primary internal ring gear.

[0005] According to various embodiments, there is provided a powertrain. The powertrain includes the dual input transmission assembly as described herein; an engine connected to the primary sun gear of the dual input transmission assembly for driving the primary sun gear to rotate; and an electric motor connected to the primary internal ring gear of the dual input transmission assembly for driving the primary internal ring gear to rotate.

[0006] According to various embodiments, there is provided a powertrain. The powertrain includes the dual input transmission assembly as described herein; an engine connected to the primary sun gear of the dual input transmission assembly for driving the primary sun gear to rotate; an electric motor connected to the primary internal ring gear of the dual input transmission assembly for driving the primary internal ring gear to rotate; a drive wheel connected to the output shaft and an air propulsion unit connected to the output ring gear, or a drive wheel connected to the output ring gear and an air propulsion unit connected to the output shaft.

[0007] According to various embodiments, there is provided a powertrain. The powertrain includes a powertrain for a vehicle capable of land and aerial transportation. The powertrain includes the dual input transmission assembly as described herein; an engine connected to the primary sun gear of the dual input transmission assembly for driving the primary sun gear to rotate; an electric motor connected to the primary internal ring gear of the dual input transmission assembly for driving the primary internal ring gear to rotate; a drive wheel connected to the output shaft and an air propulsion unit connected to the rear-output internal ring gear, or a drive wheel connected to the rear-output internal ring gear and an air propulsion unit connected to the output shaft.

Brief description of the drawings

[0008] In the drawings, like reference characters generally refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various embodiments are described with reference to the following drawings, in which:

FIG. 1A shows a schematic diagram of a dual-input transmission assembly according to various embodiments;

FIG. IB shows a schematic exploded diagram of the dual-input transmission assembly of FIG. 1A according to various embodiment;

FIG. 1C shows a schematic cross-sectional diagram of the dual-input transmission assembly of FIG. 1A according to various embodiments;

FIG. ID shows the dual-input transmission assembly of FIG. 1A to FIG. 1C in operation to drive an output shaft with a first motive power input (or a first rotary input) provided to a primary sun gear according to various embodiments;

FIG. IE shows the dual-input transmission assembly of FIG. 1A to FIG. 1C in operation to drive an output ring gear with the first motive power input (or the first rotary input) provided to the primary sun gear according to various embodiments;

FIG. IF shows the dual-input transmission assembly of FIG. 1A to FIG. 1C in operation to drive the output ring gear with a second motive power input (or a second rotary input) provided to a primary internal ring gear according to various embodiments;

FIG. 1G shows the dual-input transmission assembly of FIG. 1A to FIG. 1C in operation to drive the output shaft with the second motive power input (or the second rotary input) provided to the primary internal ring gear according to various embodiments;

FIG. 1H shows the dual-input transmission assembly of FIG. 1A to FIG. 1C in operation to drive the output shaft with the first motive power input (or the first rotary input) provided to the primary sun gear and the second motive power input (or the second rotary input) provided to the primary internal ring gear simultaneously according to various embodiments;

FIG. II shows the dual-input transmission assembly of FIG. 1A to FIG. 1C in operation to drive the output ring gear with the first motive power input (or the first rotary input) provided to the primary sun gear and the second motive power input (or the second rotary input) provided to the primary internal ring gear simultaneously according to various embodiments;

FIG. 1J shows a schematic drawing of a powertrain for a vehicle, for example a vehicle capable of land and aerial transportation, having the dual-input transmission assembly of FIG. 1A to FIG. 1C according to various embodiments;

FIG. IK shows a schematic drawing of another powertrain for a vehicle, for example a vehicle capable of land and aerial transportation, having the dual-input transmission assembly of FIG. 1A to FIG. 1C according to various embodiments;

FIG. 2A shows a schematic diagram of a dual-input transmission assembly according to various embodiments;

FIG. 2B shows a schematic exploded diagram of the dual-input transmission assembly of FIG. 2A according to various embodiment;

FIG. 2C shows a schematic cross-sectional diagram of the dual-input transmission assembly of FIG. 2A according to various embodiments;

FIG. 2D shows the dual-input transmission assembly of FIG. 2A to FIG. 2C in operation to drive an output shaft with a first motive power input (or a first rotary input) provided to a primary sun gear according to various embodiments;

FIG. 2E shows the dual-input transmission assembly of FIG. 2A to FIG. 2C in operation to drive an output ring gear with the first motive power input (or the first rotary input) provided to the primary sun gear according to various embodiments;

FIG. 2F shows the dual-input transmission assembly of FIG. 2A to FIG. 2C in operation to drive the output ring gear with a second motive power input (or a second rotary input) provided to a primary internal ring gear according to various embodiments; FIG. 2G shows the dual-input transmission assembly of FIG. 2A to FIG. 2C in operation to drive the output shaft with the second motive power input (or the second rotary input) provided to the primary internal ring gear according to various embodiments;

FIG. 2H shows the dual-input transmission assembly of FIG. 2A to FIG. 2C in operation to drive the output shaft with the first motive power input (or the first rotary input) provided to the primary sun gear and the second motive power input (or the second rotary input) provided to the primary internal ring gear simultaneously according to various embodiments;

FIG. 21 shows the dual-input transmission assembly of FIG. 2A to FIG. 2C in operation to drive the output ring gear with the first motive power input (or the first rotary input) provided to the primary sun gear and the second motive power input (or the second rotary input) provided to the primary internal ring gear simultaneously according to various embodiments;

FIG. 2J shows a schematic drawing of a powertrain for a vehicle, for example a vehicle capable of land and aerial transportation, having the dual-input transmission assembly of FIG. 2A to FIG. 2C according to various embodiments;

FIG. 2K shows a schematic drawing of another powertrain for a vehicle, for example a vehicle capable of land and aerial transportation, having the dual-input transmission assembly of FIG. 2A to FIG. 2C according to various embodiments;

FIG. 3A shows a schematic diagram of a dual-input transmission assembly according to various embodiments;

FIG. 3B shows a schematic exploded diagram of the dual-input transmission assembly of FIG. 3A according to various embodiment;

FIG. 3C shows a schematic cross-sectional diagram of the dual-input transmission assembly of FIG. 3A according to various embodiments;

FIG. 3D shows the dual-input transmission assembly of FIG. 3A to FIG. 3C in operation to drive an output shaft with a first motive power input (or a first rotary input) provided to a primary sun gear according to various embodiments; FIG. 3E shows the dual-input transmission assembly of FIG. 3A to FIG. 3C in operation to drive an output ring gear with the first motive power input (or the first rotary input) provided to the primary sun gear according to various embodiments;

FIG. 3F shows the dual-input transmission assembly of FIG. 3A to FIG. 3C in operation to drive the output ring gear with a second motive power input (or a second rotary input) provided to a primary internal ring gear according to various embodiments;

FIG. 3G shows the dual-input transmission assembly of FIG. 3A to FIG. 3C in operation to drive the output shaft with the second motive power input (or the second rotary input) provided to the primary internal ring gear according to various embodiments;

FIG. 3H shows the dual-input transmission assembly of FIG. 3A to FIG. 3C in operation to drive the output shaft with the first motive power input (or the first rotary input) provided to the primary sun gear and the second motive power input (or the second rotary input) provided to the primary internal ring gear simultaneously according to various embodiments;

FIG. 31 shows the dual-input transmission assembly of FIG. 3A to FIG. 3C in operation to drive the output ring gear with the first motive power input (or the first rotary input) provided to the primary sun gear and the second motive power input (or the second rotary input) provided to the primary internal ring gear simultaneously according to various embodiments;

FIG. 3J shows a schematic drawing of a powertrain for a vehicle, for example a vehicle capable of land and aerial transportation, having the dual-input transmission assembly of FIG. 3A to FIG. 3C according to various embodiments; and

FIG. 3K shows a schematic drawing of another powertrain for a vehicle, for example a vehicle capable of land and aerial transportation, having the dual-input transmission assembly of FIG. FIG. 3A to FIG. 3C according to various embodiments.

Detailed description

[0009] Embodiments described below in the context of the apparatus are analogously valid for the respective methods, and vice versa. Furthermore, it will be understood that the embodiments described below may be combined, for example, a part of one embodiment may be combined with a part of another embodiment.

[00010] It should be understood that the terms “on”, “over”, “top”, “bottom”, “down”, “side”, “back”, “left”, “right”, “front”, “lateral”, “side”, “up”, “down” etc., when used in the following description are used for convenience and to aid understanding of relative positions or directions, and not intended to limit the orientation of any device, or structure or any part of any device or structure. In addition, the singular terms “a”, “an”, and “the” include plural references unless context clearly indicates otherwise. Similarly, the word “or” is intended to include “and” unless the context clearly indicates otherwise.

[00011] Various embodiments generally relate to a dual-input transmission assembly and a powertrain having the dual-input transmission assembly for a vehicle. In particular, various embodiments generally relate to a dual-input transmission assembly for a vehicle capable of land and aerial transportation (i.e. flying car), and a powertrain for the vehicle capable of land and aerial transportation.

[00012] According to various embodiments, the dual-input transmission assembly may be coupled to two separate independent prime movers (for example one engine and one electric motor, or two separate independent engine, or two separate independent electric motors) to provide two separate motive power inputs (or dual inputs) to the dual-input transmission assembly. According to various embodiments, the dual-input transmission assembly may be configured to selectively transmit and/or adapt either a first motive power input (or a first rotary input) from a first prime mover, or a second motive power input (or a second rotary input) from a second prime mover, or a combined motive power input (or a combined rotary input) from both the first prime mover and the second prime mover together as a transmission-output for driving a propulsion unit (for example a drive wheel or an air propulsion unit). According to various embodiments, the dual-input transmission assembly may be coupled to two separate independent propulsion units (for example one drive wheel and one air propulsion unit). According to various embodiments, the dual-input transmission assembly may be configured to provide the transmission-output to selectively drive either the first propulsion unit (e.g. the drive wheel) or the second propulsion unit (e.g. the air propulsion unit) or both. The two separate independent propulsion units may be two different types of propulsion unit, such as air propulsion unit and ground propulsion unit. Accordingly, the dual-input transmission assembly may be operable to selectively transmit and/or adapt either a first motive power input from a first prime mover, or a second motive power input from a second prime mover, or a combined motive power input from both the first prime mover and the second prime mover together as the transmission-output to selectively drive the first propulsion unit (e.g. the drive wheel) or the second propulsion unit (e.g. the air propulsion unit) or both.

[00013] According to various embodiments, the powertrain may include the dual-input transmission assembly and the two separate independent prime movers. According to various embodiments, the prime mover may generate the motive power input for the dual input transmission assembly based on transforming energy, such as mechanical energy, potential energy, electrical energy, chemical energy, solar energy, nuclear energy, into kinetic energy for propulsion purposes. According to various embodiments, the powertrain may further include the two separate independent propulsion units. According to various embodiments, the two separate independent propulsion units may be configured for generating ground propulsion and air propulsion respectively.

[00014] According to various embodiments, the vehicle capable of land and aerial transportation or a flying car may be a roadable aircraft or a vehicle that provides transportation by both ground and air or a vehicle that is capable of being driven on a road and flown in the air or a multi-mode transport vehicle for ground travel and air travel. [00015] According to various embodiments, the powertrain may be readily switchable, via the dual-input transmission assembly, between the two separate independent prime movers (for example an engine and an electric motor) as redundancy to serve as backup or fail-safe for each other. According to various embodiments, the powertrain may also be readily switchable, via the dual-input transmission assembly, between the two separate independent propulsion units (e.g. the drive wheel and the air propulsion unit) for providing ground propulsion or air propulsion respectively to the vehicle. According to various embodiments, the powertrain may allow for a true dual redundancy safety system, whereby if one of the prime movers of the vehicle (e.g. the electric motor) fails, the vehicle may still be maneuvered and powered using the other prime mover (e.g. the engine), or vice versa, regardless of the propulsion unit (the drive wheel or the air propulsion unit) that is being driven.

[00016] According to various embodiments, the powertrain may enable travel via multi modes. For example, the powertrain may enable travel via four different modes of operation, namely, land travel in mechanical mode, land travel in electrical mode, flight in mechanical mode, and flight in electrical mode. As another example, the powertrain may enable travel via six different modes of operation, namely, land travel in mechanical mode, land travel in electrical mode, land travel in hybrid mode, flight in mechanical mode, flight in electrical mode, and flight in hybrid mode. According to various embodiments, for land travel in mechanical mode, the dual-input transmission assembly may be operated to transmit the motive power input from the engine to the drive wheel. According to various embodiments, for land travel in electrical mode, the dual-input transmission assembly may be operated to transmit the motive power input from the electric motor to the drive wheel. According to various embodiments, for land travel in hybrid mode, the dual-input transmission assembly may be operated to transmit the motive power inputs from both the engine and the electric motor to the drive wheel. According to various embodiments, for flight in mechanical mode, the dual-input transmission assembly may be operated to transmit the motive power input from the engine to the air propulsion unit. According to various embodiments, for flight in electrical mode, the dual-input transmission assembly may be operated to transmit the motive power input from the electric motor to the air propulsion unit. According to various embodiments, for flight in hybrid mode, the dual-input transmission assembly may be operated to transmit the motive power inputs from both the engine and the electric motor to the air propulsion unit.

[00017] The following examples pertain to various embodiments.

[00018] Example 1 is a dual input transmission assembly including an primary internal ring gear rotatable about a central rotational axis extending though a centre of the primary internal ring gear; a transfer internal ring gear arranged side-by-side to the primary internal ring gear along the central rotational axis in a coaxial manner and rotatable about the central rotational axis; a set of planetary gears, each planetary gear extending axially from within the primary internal ring gear to within the transfer internal ring gear in a manner parallel to the central rotational axis, each planetary gear having a first axial portion in engagement with the primary internal ring gear and a second axial portion in engagement with the transfer internal ring gear; a planet carrier to hold the set of planetary gears, the planet carrier being rotatable about the central rotational axis so as to cause the set of planetary gears to revolve around the central rotational axis, wherein each planetary gear is rotatably mounted to the planet carrier so as to be rotatable about its axis of rotation; an primary sun gear in mesh engagement with the first axial portions of the set of planetary gears, the primary sun gear being coaxial with the primary internal ring gear and rotatable about the central rotational axis; and a planet carrier brake to selectively engage the planet carrier so as to lock the planet carrier from rotating about the central rotational axis, wherein a rotation of the transfer internal ring gear is generated by providing a rotary input to the primary sun gear with the planet carrier brake in engagement with the planet carrier, or a rotary input to the primary internal ring gear, or a rotary input to the primary sun gear together with a reverse rotary input to the primary internal ring gear.

[00019] In Example 2, the subject matter of Example 1 may optionally include that a gear ratio between the primary internal ring gear and the first axial portion of each planetary gear may be different from a gear ratio between the transfer internal ring gear and the second axial portion of each planetary gear. For example, the gear ratio between the primary internal ring gear and the first axial portion of each planetary gear may be higher than the gear ratio between the transfer internal ring gear and the second axial portion of each planetary gear. [00020] In Example 3, the subject matter of Example 1 or Example 2 may optionally include a transfer shaft extending longitudinally from the primary sun gear in an integral manner along the central rotational axis in a direction from the primary internal ring gear towards and through the transfer internal ring gear so as to be rotated together with the primary sun gear, wherein the transfer shaft is free from engaging the second axial portions of the set of planetary gears.

[00021] In Example 4, the subject matter of any one of Examples 1 to 3 may optionally include an output shaft along the central rotational axis and a clutch mechanism disposed between the transfer internal ring gear and the output shaft along the central rotational axis, the clutch mechanism being coupled to the transfer internal ring gear and operable to selectively connect or disconnect the transfer internal ring gear to the output shaft for selectively transmitting the rotation of the transfer internal ring gear to the output shaft. [00022] In Example 5, the subject matter of any one of Examples 1 to 3 may optionally include an output shaft along the central rotational axis, an output ring gear surrounding the output shaft in a coaxial manner, and a clutch mechanism disposed between the transfer internal ring gear and the output shaft along the central rotational axis, the clutch mechanism being coupled to the transfer internal ring gear and operable to selectively connect or disconnect the transfer internal ring gear to one or both of the output shaft and the output ring gear for selectively transmitting the rotation of the transfer internal ring gear to one or both of the output shaft and the output ring gear.

[00023] In Example 6, the subject matter of Example 3 may optionally include an output shaft along the central rotational axis, an output ring gear surrounding the output shaft in a coaxial manner, and a clutch mechanism disposed between the transfer shaft and the output shaft along the central rotational axis, the clutch mechanism being operable to selectively couple the transfer internal ring gear or the transfer shaft to one or both of the output shaft and the output ring gear for selectively transmitting the rotation of the transfer internal ring gear or the transfer shaft to one or both of the output shaft and the output ring gear.

[00024] In Example 7, the subject matter of Example 6 may optionally include that the clutch mechanism may include a first set of clutch elements and a second set of clutch elements interconnected in a manner so as to be rotatable together in a synchronized manner about the central rotational axis, wherein the first set of clutch elements may include a transfer- shaft-engagement-clutch-element movable along the central rotational axis towards and away from the transfer shaft for engaging and disengaging with the transfer shaft, and a transfer-ring-gear-engagement-clutch-element movable along the central rotational axis towards and away from the transfer internal ring gear for engaging and disengaging with the transfer internal ring gear, wherein the second set of clutch elements may include an output-shaft-engagement-clutch-element movable along the central rotational axis towards and away from the output shaft for engaging and disengaging with the output shaft, and an output-ring-gear-engagement-clutch-element movable along the central rotational axis towards and away from the output ring gear for engaging and disengaging with the output ring gear.

[00025] In Example 8, the subject matter of Example 7 may optionally include that the transfer-ring-gear-engagement-clutch-element may be movable relative to the transfer- shaft-engagement-clutch-element in a telescopic manner so as to extend away from the transfer- shaft-engagement-clutch-element to engage with the transfer internal ring gear and to retract back towards the transfer- shaft-engagement-clutch-element to disengage from the transfer internal ring gear, wherein the output-ring-gear-engagement-clutch-element may be movable relative to the output-shaft-engagement-clutch-element in a telescopic manner so as to extend away from the output- shaft-engagement-clutch-element to engage with the output ring gear and to retract back towards the output- shaft-engagement-clutch-element to disengage from the output ring gear. [00026] In Example 9, the subject matter of Example 7 or Example 8 may optionally include that the transfer-shaft-engagement-clutch-element and the output-shaft- engagement-clutch-element may be movable relative to each other in a telescopic manner so as to extend the transfer-shaft-engagement-clutch-element away from the output-shaft- engagement-clutch-element to engage with the transfer shaft and to retract the transfer- shaft-engagement-clutch-element back towards the output-shaft-engagement-clutch- element to disengage from the transfer shaft, or to extend the output-shaft-engagement-clutch-element away from the transfer-shaft- engagement-clutch-element to engage with the output shaft and to retract the output- shaft- engagement-clutch-element back towards the transfer- shaft-engagement-clutch-element to disengage from the output shaft, or to extend away from each other such that the transfer-shaft-engagement-clutch- element engages the transfer shaft and the output-shaft-engagement-clutch-element engages the output shaft, and to retract towards each other such that the transfer- shaft-engagement- clutch-element disengages from the transfer shaft and the output-shaft-engagement-clutch- element disengages from the output shaft.

[00027] In Example 10, the subject matter of Example 3 may optionally include an output shaft along the central rotational axis, and a clutch mechanism disposed between the transfer shaft and the output shaft along the central rotational axis, the clutch mechanism being operable to couple the transfer internal ring gear or the transfer shaft to the output shaft for transmitting the rotation of the transfer internal ring gear or the transfer shaft to the output shaft.

[00028] In Example 11, the subject matter of Example 10 may optionally include that the clutch mechanism may include a first set of clutch elements and a second set of clutch elements interconnected in a manner so as to be rotatable together in a synchronized manner about the central rotational axis, wherein the first set of clutch elements may include a transfer- shaft-engagement-clutch-element movable along the central rotational axis towards and away from the transfer shaft for engaging and disengaging with the transfer shaft, and a transfer-ring-gear-engagement-clutch-element movable along the central rotational axis towards and away from the transfer internal ring gear for engaging and disengaging with the transfer internal ring gear, wherein the second set of clutch elements may include an output-shaft-engagement-clutch-element movable along the central rotational axis towards and away from the output shaft for engaging and disengaging with the output shaft.

[00029] In Example 12, the subject matter of Example 11 may optionally include that the transfer-ring-gear-engagement-clutch-element may be movable relative to the transfer- shaft-engagement-clutch-element in a telescopic manner so as to extend away from the transfer- shaft-engagement-clutch-element to engage with the transfer internal ring gear and to retract back towards the transfer- shaft-engagement-clutch-element to disengage from the transfer internal ring gear.

[00030] In Example 13, the subject matter of Example 11 of 12 may optionally include that the transfer- shaft-engagement-clutch-element and the output- shaft-engagement-clutch- element may be movable relative to each other in a telescopic manner so as to extend the transfer-shaft-engagement-clutch-element away from the output-shaft-engagement-clutch- element to engage with the transfer shaft and to retract the transfer-shaft-engagement- clutch-element back towards the output-shaft-engagement-clutch-element to disengage from the transfer shaft.

[00031] In Example 14, the subject matter of Example 13 may optionally include that the output-shaft-engagement-clutch-element may be permanently coupled to the output shaft, or the output- shaft-engagement-clutch-element may be extendable away from the transfer- shaft-engagement-clutch-element to engage with the output shaft and retractable back towards the transfer-shaft-engagement-clutch-element to disengage from the output shaft. [00032] In Example 15, the subject matter of any one of claims 1 to 14 may optionally include a rear-output internal ring gear arranged side-by-side to the primary internal ring gear opposite the transfer internal ring gear along the central rotational axis in a coaxial manner and rotatable about the central rotational axis, wherein each planetary gear has a third axial portion extending from the first axial portion in a direction opposite the second axial portion so as to extend to within the rear-output internal ring gear, the third axial portion being in engagement with the rear-output internal ring gear.

[00033] In Example 16, the subject matter of any one of Examples 1 to 15 may optionally include an input shaft extending from the primary sun gear in a direction opposite and away from the transfer internal ring gear in an integral manner along the central rotational axis so as to rotate the primary sun gear when the input shaft is being driven to rotate. [00034] In Example 17, the subject matter of Example 16 in combination with Example 15 may optionally include that the input shaft may be free from engaging the third axial portions of the set of planetary gears.

[00035] Example 18 is a powertrain for a vehicle including: the dual input transmission assembly according to any one of Examples 1 to 17; an engine connected to the primary sun gear of the dual input transmission assembly for driving the primary sun gear to rotate; and an electric motor connected to the primary internal ring gear of the dual input transmission assembly for driving the primary internal ring gear to rotate.

[00036] Example 19 is a powertrain for a vehicle capable of land and aerial transportation, the powertrain including: the dual input transmission assembly according to any one of Examples 5, 6 to 9; an engine connected to the primary sun gear of the dual input transmission assembly for driving the primary sun gear to rotate; an electric motor connected to the primary internal ring gear of the dual input transmission assembly for driving the primary internal ring gear to rotate; a drive wheel connected to the output shaft and an air propulsion unit connected to the output ring gear, or a drive wheel connected to the output ring gear and an air propulsion unit connected to the output shaft.

[00037] Example 20 is a powertrain for a vehicle capable of land and aerial transportation, the powertrain including: the dual input transmission assembly according to any one of Examples 4 to 14 in combination with Example 15; an engine connected to the primary sun gear of the dual input transmission assembly for driving the primary sun gear to rotate; an electric motor connected to the primary internal ring gear of the dual input transmission assembly for driving the primary internal ring gear to rotate; a drive wheel connected to the output shaft and an air propulsion unit connected to the rear-output internal ring gear, or a drive wheel connected to the rear-output internal ring gear and an air propulsion unit connected to the output shaft.

[00038] In Example 21 , the subject matter of any one of Examples 18 to 20 may optionally include that the planet carrier brake of the dual input transmission assembly may engage the planet carrier of the dual input transmission assembly to lock the planet carrier from rotating when the electric motor is not driving the primary internal ring gear. [00039] FIG. 1A shows a schematic diagram of a dual-input transmission assembly 110 according to various embodiments. FIG. IB shows a schematic exploded diagram of the dual-input transmission assembly 110 of FIG. 1A according to various embodiment. FIG. 1C shows a schematic cross-sectional diagram of the dual-input transmission assembly 110 of FIG. 1A according to various embodiments. According to various embodiments, the dual input transmission assembly 110 may be configured receive two separate motive power inputs (or dual inputs) from two independent prime movers or input sources (i.e. a first and a second prime mover). According to various embodiments, the dual input transmission assembly may be configured to selectively transmit and/or adapt either a first motive power input (or a first rotary input) from a first prime mover, or a second motive power input (or a second rotary input) from a second prime mover, or a combined motive power input (or a combined rotary input) from both the first prime mover and the second prime mover together as a transmission-output from the dual-input transmission assembly 110.

[00040] According to various embodiments, the dual input transmission assembly 110 may include a primary internal ring gear 122. According to various embodiments, the primary internal ring gear 122 may be rotatable about a central rotational axis 112 extending though a centre of the primary internal ring gear 122. Accordingly, the primary internal ring gear 122 may not be fixed and may be free to rotate about the central rotational axis 112. The central rotational axis 112 may be passing through a centre point of an inner space 122a surrounded by the primary internal ring gear 122. In other words, the central rotational axis 112 may intersect the centre of the primary internal ring gear 122, whereby a radius of the primary internal ring gear 122 may be measured therefrom. Hence, the primary internal ring gear 122 may be rotated about an axis of the primary internal ring gear 122 from which the radius of the primary internal ring gear 122 is measured. Accordingly, the axis of the primary internal ring gear 122 may coincide with the central rotational axis 112. According to various embodiments, the primary internal ring gear 122 may be coupled to one of the two independent prime movers for receiving a motive power input (or rotary input). Accordingly, the primary internal ring gear 122 may receive the motive power input (or rotary input) from one of the two independent prime movers so as to serve (or function) as an input ring gear. [00041] According to various embodiments, the dual input transmission assembly 110 may include a transfer internal ring gear 132. According to various embodiments, the transfer internal ring gear 132 may be arranged side-by-side to the primary internal ring gear 122 along the central rotational axis 112 in a coaxial manner and rotatable about the central rotational axis 112. Accordingly, the central rotational axis 112 may be extending through or intersecting a centre of the transfer internal ring gear 132 or passing through a centre point of an inner space 132a surrounded by the transfer internal ring gear 132. Thus, the transfer internal ring gear 132 may not be fixed and may be free to rotate about the central rotational axis 112. A radius of the transfer internal ring gear 132 may be measured from the centre of the transfer internal ring gear 132. Hence, the transfer internal ring gear 132 may be rotated about an axis of the transfer internal ring gear 132 from which the radius of the transfer internal ring gear 132 is measured. Accordingly, the axis of the transfer internal ring gear 132 may coincide with the central rotational axis 112.

[00042] According to various embodiments, the dual input transmission assembly 110 may include a set of planetary gears 124. According to various embodiments, each planetary gear 124 may be a cylindrical gear. According to various embodiments, each planetary gear 124 may extend axially from within the primary internal ring gear 122 to within the transfer internal ring gear 132 in a manner parallel to the central rotational axis 112. Accordingly, an axis of rotation of each planetary gear 124 (or gear axis of each planetary gear 124 or centreline of each planetary gear 124) may be parallel to the central rotational axis 112. Further, each planetary gear 124 may extend along its axis of rotation from within the inner space 122a surrounded by the primary internal ring gear 122 to within the inner space 132a surrounded by the transfer internal ring gear 132 such that a first axial portion 124a of each planetary gear 124 lies within the inner space 122a surrounded by the primary internal ring gear 122 and a second axial portion 124b of each planetary gear 124 lies within the inner space 132a surrounded by the transfer internal ring gear 132. According to various embodiments, a total width (or axial length) of each planetary gear 124 along its axis of rotation may extend across a face width of the primary internal ring gear 122 and a face width of the transfer internal ring gear 132. According to various embodiments, the total width (or axial length) of each planetary gear 124 along its axis of rotation may be equal or greater than a combination of the face width of the primary internal ring gear 122 and the face width of the transfer internal ring gear 132. According to various embodiments, the first axial portion 124a of each planetary gear 124 may be in engagement with the primary internal ring gear 122 and the second axial portion 124b of each planetary gear 124 may be in engagement with the transfer internal ring gear 132. Accordingly, the first axial portion 124a of each planetary gear 124 may mesh with the primary internal ring gear 122 and the second axial portion 124b of each planetary gear 124 may mesh with the transfer internal ring gear 132 such that the primary internal ring gear 122, the set of planetary gears 124 planetary gears 124, and the transfer internal ring gear 132 may form a gear train. According to various embodiments, the face width of the primary internal ring gear 122 may be equal to or less than an axial length of the first axial portion 124a of each planetary gear 124 such that the primary internal ring gear 122 may only mesh with the first axial portion 124a of each planetary gear 124. According to various embodiments, the face width of the transfer internal ring gear 132 may be equal to or less than an axial length of the second axial portion 124b of each planetary gear 124 such that the transfer internal ring gear 132 only mesh with the second axial portion 124b of each planetary gear 124. According to various embodiments, the first axial portion 124a of each planetary gear 124 and the second axial portion 124b of each planetary gear 124 may be integral such that each planetary gear 124 may rotate as a single unit with the first axial portion 124a and the second axial portion 124b of each planetary gear 124 rotating together in unison. According to various embodiments, the set of planetary gears 124 may include two or three or four or five or six or more planetary gears 124.

[00043] According to various embodiments, the dual input transmission assembly 110 may include a planet carrier 126. According to various embodiments, the planet carrier 126 may hold or support or carry the set of planetary gears 124. According to various embodiments, the set of planetary gears 124 may be held or supported or carried by the planet carrier 126 in a manner so as to be equally distributed around the central rotational axis 112 and equidistant from the central rotational axis 112. According to various embodiments, the planet carrier 126 may be rotatable about the central rotational axis 112 so as to cause the set of planetary gears 124 to revolve around the central rotational axis 112. Accordingly, the set of planetary gears 124 may move in a circular course or orbit around the central rotational axis 112 together with the planet carrier 126 rotating about the central rotational axis 112. According to various embodiments, each planetary gear 124 may be rotatably mounted to the planet carrier 126 so as to be rotatable about its axis of rotation. Accordingly, each planetary gear 124 may be independently rotatable with respect to the planet carrier 126 about the axis of rotation of each planetary gear 124. Hence, each planetary gear 124 may rotate about its axis of rotation relative to the planet carrier 126 while the set of planetary gears 124 may revolve around the central rotational axis 112 together with the planet carrier 126 rotating about the central rotational axis 112.

[00044] According to various embodiments, the planet carrier 126 may include a circular carrier plate 126a having a plurality of holes 126b distributed around the circular carrier plate 126a. According to various embodiments, the set of planetary gears 124 may be inserted through the plurality of holes 126b of the circular carrier plate 126a. According to various embodiments, each planetary gear 124 may be rotatable about its axis of rotation within a corresponding hole 126b of the circular carrier plate 126a through which it is inserted. Accordingly, each planetary gear 124 may be held or supported or carried by the planet carrier 126 with the planetary gear 124 being inserted through the corresponding hole 126b of the circular carrier plate 126a such that the first axial portion 124a of the planetary gear 124 may be on one side of the circular carrier plate 126a and the second axial portion 124b of the planetary gear 124 may be on another side of the circular carrier plate 126a. According to various embodiments, each planetary gear 124 may include a neck portion 124c between the axial portion 124a and the second axial portion 124b. Accordingly, the neck portion 124c of each planetary gear 124 may lie within the corresponding hole 126b of the circular carrier plate 126a. According to various embodiments, the neck portion 124c of each planetary gear 124 may be free of gear teeth and may have a smooth circumferential surface. Accordingly, each planetary gear 124 may be rotated relative to the corresponding hole 126b of the circular carrier plate 126a with minimum resistance or friction between the neck portion 124c of each planetary gear 124 and the corresponding hole 126b of the circular carrier plate 126a.

[00045] According to various embodiments, the dual input transmission assembly 110 may include a primary sun gear 128. According to various embodiments, the primary sun gear 128 may be in mesh engagement with the first axial portions 124a of the set of planetary gears 124. According to various embodiments, the primary sun gear 128 may be coaxial with the primary internal ring gear 122 and rotatable about the central rotational axis 112. Accordingly, the primary sun gear 128 and the primary internal ring gear 122 may be in a concentric arrangement with the primary internal ring gear 122 surrounding a circumference of the primary sun gear 128, whereby the set of planetary gears 124 may be disposed around the primary sun gear 128 such that the first axial portions 124a of the set of planetary gears 124 may be between the primary sun gear 128 and the primary internal ring gear 122. According to various embodiments, the primary sun gear 128 may have a face width equal or less than the axial length of the first axial portions 124a of the set of planetary gears 124 such that primary sun gear 128 may only mesh with the first axial portions 124a of the set of planetary gears 124. Hence, the primary sun gear 128, the first axial portions 124a of the set of planetary gears 124 and the primary internal ring gear 122 may form a planetary-gear- train-zone 120. According to various embodiments, the primary sun gear 128 may be free from engagement with the second axial portions 124b of the set of planetary gears 124. Accordingly, the primary sun gear 128 may not be in contact or touching the second axial portions 124b of the set of planetary gears 124. According to various embodiments, the primary sun gear 128 may be coupled to a further prime mover of the two independent prime movers for receiving a further motive power input (or rotary input). Accordingly, the primary sun gear 128 may receive the further motive power input (or rotary input) from the further prime mover of the two independent prime movers so as to serve (or function) as an input sun gear.

[00046] According to various embodiments, the transfer internal ring gear 132 and the second axial portions 124b of the set of planetary gears 124 may form a pinions-and- intemal-gear-set-zone 130 without the primary sun gear 128 being in engagement or contact with the second axial portions 124b of the set of planetary gears 124, whereby the second axial portion 124b of each planetary gear 124 may serve as a pinion for engaging only the transfer ring gear 132. According to various embodiments, the set of planetary gears 124 may be common to both the planetary-gear-train-zone 120 and the pinions-and-intemal- gear-set-zone 130. Accordingly, the set of planetary gears 124 may serve to transmit or transfer rotation generated from the planetary-gear-train-zone 120 to the pinions-and- intemal-gear-set-zone 130 for driving the transfer internal ring gear 132. Hence, the set of planetary gears 124 may function like an idler gear to transmit motion from the planetary- gear-train-zone 120 to the pinions-and-intemal-gear-set-zone 130 so as to drive the transfer internal ring gear 132.

[00047] According to various embodiments, a gear ratio between the primary internal ring gear 122 and the first axial portion 124a of each planetary gear 124 may be different from a gear ratio between the transfer internal ring gear 132 and the second axial portion 124b of each planetary gear 124. For example, a gear ratio between the primary internal ring gear 122 and the first axial portion 124a of each planetary gear 124 may be higher than a gear ratio between the transfer internal ring gear 132 and the second axial portion 124b of each planetary gear 124. According to various embodiments, the first axial portion 124a of each planetary gear 124 and the second axial portion 124b of each planetary gear 124 may have different number of teeth and/or different diameter. Correspondingly, the primary internal ring gear 122 and the transfer internal ring gear 132 may have different number of teeth and/or different diameter. For example, the first axial portion 124a of each planetary gear 124 may have a higher number of teeth (and/or a bigger diameter) than the second axial portion 124b of each planetary gear 124 while the primary internal ring gear 122 may have a higher number of teeth (and/or bigger diameter) than the transfer internal ring gear 132 in a manner such that the gear ratio between the primary internal ring gear 122 and the first axial portion 124a of each planetary gear 124 may be higher than the gear ratio between the transfer internal ring gear 132 and the second axial portion 124b of each planetary gear 124. [00048] According to various embodiments, the dual input transmission assembly 110 may include a planet carrier brake 125. According to various embodiments, the planet carrier brake 125 may be configured to selectively engage the planet carrier 126 so as to lock the planet carrier 126 from rotating about the central rotational axis 112. According to various embodiments, the planet carrier brake 125 may be movable between a disengaged position and an engaged position. According to various embodiments, in the disengaged position, the planet carrier brake 125 may be spaced apart from the planet carrier 126 or in a state of non-contact with the planet carrier 126 such that the planet carrier 126 may rotate freely about the central rotational axis 112. According to various embodiments, in the engaged position, the planet carrier brake 125 may be moved towards the planet carrier 126 so as to engage and stop the planet carrier 126 from rotating about the central rotational axis 112, for example, via friction engagement. Accordingly, the planet carrier brake 125 may be operable, automatically or manually, to selectively engage the planet carrier 126 for locking the planet carrier 126 when required to stop the planet carrier 126 from rotating about the central rotational axis 112. For example, the planet carrier brake 125 may be operable manually based on a user control and input. For example, the planet carrier brake 125 may be operable automatically in response to a detection that the second motive power input or the second rotary input is provided to the primary internal ring gear 122 or that the second prime mover or second in put source is activated.

[00049] According to various embodiments, the dual-input transmission assembly 110 may be operated to generate an output rotation by selectively using one or both of the two independent separate input sources or prime movers (e.g. the engine and the electric motor) coupled respectively to the primary sun gear 128 and the primary internal ring gear 122 of the dual-input transmission assembly 110. According to various embodiments, the dual input transmission assembly 110 may be operated to generate the rotation of the transfer internal ring gear 132 by selectively providing a rotary input (e.g. the first motive power input or the first rotary input) to the primary sun gear 128 with the planet carrier brake 125 in engagement with the planet carrier 126, or a rotary input (e.g. the second motive power input or the second rotary input) to the primary internal ring gear 122, or a rotary input (e.g. the first motive power input or the first rotary input) to the primary sun gear 128 together with a reverse rotary input (e.g. the second motive power input or the second rotary input) to the primary internal ring gear 122. Accordingly, the dual-input transmission assembly 110 may be coupled to the two independent separate input sources or prime movers (e.g. the engine and the electric motor) for providing rotary input to the dual-input transmission assembly 110 via either one of the two independent separate input sources or prime movers (e.g. the engine and the electric motor) or both of the two independent separate input sources or prime movers (e.g. the engine and the electric motor) simultaneously so as to drive the transfer internal ring gear 132 to rotate about the central rotational axis 112.

[00050] According to various embodiments, when the primary sun gear 128 is receiving the first motive power input (or the first rotary input) from the first prime mover (e.g. the engine), the planet carrier brake 125 may be engaged with the planet carrier 126 (or in the engaged position) so as to lock the planet carrier 126 from rotating about the central rotational axis 112. Accordingly, the primary sun gear 128 may rotate and drive the set of planetary gears 124 to respectively rotate about their axes of rotation relative to the stationary planet carrier 126 via the engagement between the primary sun gear 128 and the first axial portions 124a of set of planetary gear 124 while the primary internal ring gear 122 may be freewheeling or rotated as a result of the rotating set of planetary gears 124 as no motive power input (e.g. from the electric motor) is provided to the primary internal ring gear 122. With the set of planetary gears 124 rotating about their axes of rotation relative to the stationary planet carrier 126, the second axial portions 124b of set of planetary gear 124 in engagement with the transfer internal ring gear 132 may drive the transfer internal ring gear 132. Hence, the set of planetary gears 124 being common to both the planetary-gear- train-zone 120 and the pinions-and-internal-gear-set-zone 130 may serve to transmit or transfer a rotation of the primary sun gear 128 of the planetary-gear-train-zone 120 (which is driven by the first motive power input or the first rotary input) to drive the transfer internal ring gear 132 of the pinions-and-intemal-gear-set-zone 130. Hence, the set of planetary gears 124 may function like idler gears to transmit rotary motion from the primary sun gear 128 to the transfer internal ring gear 132 via the first axial portions 124a of set of planetary gear 124 in engagement with the primary sun gear 128 and the second axial portions 124b of set of planetary gear 124 in engagement with the transfer internal ring gear 132, wherein the set of planetary gear 124 may be rotating about their axes of rotation in a synchronized manner (at the same time and speed) with each planetary gear 124 rotating as a single unit. [00051] According to various embodiments, when the primary internal ring gear 122 is receiving the second motive power input (or the second rotary input) from the second prime mover (e.g. the electric motor), the primary sun gear 128 may remain coupled to the first prime mover (e.g. the engine). However, since the first prime mover is not providing the first motive power input (or the first rotary input), the primary sun gear 128 may be locked from rotating by the connection between the primary sun gear 128 and the first prime mover. Further, the planet carrier brake 125 may be disengaged from the planet carrier 126 (or in the disengaged position) such that the planet carrier 126 may rotate freely about the central rotational axis 112. In other words, the planet carrier 126 may be freewheeling and may be rotated as a result of the primary internal ring gear 122 driving the set of planetary gears 124. Accordingly, the primary internal ring gear 122 may rotate and drive the set of planetary gears 124 to respectively rotate about their axes of rotation relative to the planet carrier 126 and to revolve about the stationary primary sun gear 128 as the planet carrier 126 rotates about the central rotational axis 112 via the engagement between the primary internal ring gear 122 and the first axial portions 124a of set of the planetary gears 124. With the set of planetary gears 124 rotating about their axes of rotation and revolving about the stationary primary sun gear 128 together with the planet carrier 126 rotating about the central rotational axis 112, the second axial portions 124b of set of planetary gear 124 may drive the transfer internal ring gear 132. Hence, the set of planetary gears 124 being common to both the planetary-gear-train-zone 120 and the pinions-and-internal-gear-set-zone 130 may serve to transmit or transfer a rotation of the primary internal ring gear 122 of the planetary-gear- train-zone 120 (which is driven by the second motive power input or the second rotary input) to drive the transfer internal ring gear 132 of the pinions-and-intemal- gear-set-zone 130. Hence, the set of planetary gears 124 may function like idler gears to transmit motion from the primary internal ring gear 122 to the transfer internal ring gear 132 via the first axial portions 124a of set of planetary gear 124 in engagement with the primary internal ring gear 122 and the second axial portions 124b of set of planetary gear 124 in engagement with the transfer internal ring gear 132.

[00052] According to various embodiments, the primary sun gear 128 may receive the first motive power input (or the first rotary input) from the first prime mover (e.g. the engine) and the primary internal ring gear 122 may receive the second motive power input (or the second rotary input) from the second prime mover (e.g. the electric motor) simultaneously whereby the first motive power input (or the first rotary input) and the second motive power input (or the second rotary input) may be counter-rotating so as to rotate and drive the set of planetary gears 124. The second motive power input (or the second rotary input) may be rotating in a reverse direction with respect to the first motive power input (or the first rotary input). Accordingly, the counter-rotation between the primary sun gear 128 and the primary internal ring gear 122 may drive the set of planetary gears 124 via the engagement between the primary sun gear 128 and the first axial portions 124a of set of planetary gear 124 and the engagement between the primary internal ring gear 122 and the first axial portions 124a of set of the planetary gears 124. According to various embodiments, the planet carrier brake 125 may be disengaged from the planet carrier 126 (or in the disengaged position) such that the planet carrier 126 may rotate freely about the central rotational axis 112. In other words, the planet carrier 126 may be freewheeling and may be rotated as a result of counter-rotation between the primary sun gear 128 and the primary internal ring gear 122 driving the set of planetary gears 124.

[00053] According to various embodiments, the first motive power input (or the first rotary input) from the first prime mover (e.g. the engine) rotating the primary sun gear 128 and the second motive power input (or the second rotary input) from the second prime mover (e.g. the electric motor) rotating the primary internal ring gear 122 may be coordinated such that the counter-rotation between the primary sun gear 128 and the primary internal ring gear 122 may drive and rotate the set of planetary gears 124 about their axes of rotation relative to the planet carrier 126 without any resultant rotation of the planet carrier 126 about the central rotational axis 112. Accordingly, the coordinated counter-rotation between the primary sun gear 128 and the primary internal ring gear 122 may drive and rotate the set of planetary gears 124 about their axes of rotation while maintaining the planet carrier 126 stationary. With the set of planetary gears 124 rotating about their axes of rotation relative to the stationary planet carrier 126, the second axial portions 124b of set of planetary gear 124 may drive the transfer internal ring gear 132. Hence, the set of planetary gears 124 being common to both the planetary-gear-train-zone 120 and the pinions-and-internal-gear-set- zone 130 may serve to transmit or transfer the combined rotary inputs of the primary sun gear 128 and the primary internal ring gear 122 of the planetary-gear-train-zone 120 to drive the transfer internal ring gear 132 of the pinions-and-internal-gear-set-zone 130. Hence, the set of planetary gears 124 may function like idler gears to transmit motion from the primary sun gear 128 and the primary internal ring gear 122 to the transfer internal ring gear 132 via the first axial portions 124a of set of planetary gear 124 in engagement with both the primary sun gear 128 and the primary internal ring gear 122 and the second axial portions 124b of set of planetary gear 124 in engagement with the transfer internal ring gear 132.

[00054] According to various embodiments, the first motive power input (or the first rotary input) from the first prime mover (e.g. the engine) rotating the primary sun gear 128 and the second motive power input (or the second rotary input) from the second prime mover (e.g. the electric motor) rotating the primary internal ring gear 122 may be uncoordinated such that the counter-rotation between the primary sun gear 128 and the primary internal ring gear 122 may drive and rotate the set of planetary gears 124 to respectively rotate about their axes of rotation relative to the planet carrier 126 together with a resultant rotation of the planet carrier 126 about the central rotational axis 112. Accordingly, the uncoordinated counter-rotation between the primary sun gear 128 and the primary internal ring gear 122 may drive and rotate the set of planetary gears 124 about their axes of rotation together with the resultant rotation of the planet carrier 126 about the central rotational axis 112. With the set of planetary gears 124 rotating about their axes of rotation relative to the stationary planet carrier 126 along with the resultant rotation of the planet carrier 126 about the central rotational axis 112, the second axial portions 124b of set of planetary gear 124 may drive the transfer internal ring gear 132. Hence, the set of planetary gears 124 being common to both the planetary-gear-train-zone 120 and the pinions-and-internal-gear-set-zone 130 may serve to transmit or transfer the combined rotary inputs of the primary sun gear 128 and the primary internal ring gear 122 of the planetary-gear- train-zone 120 to drive the transfer internal ring gear 132 of the pinions-and-internal-gear-set-zone 130. Hence, the set of planetary gears 124 may function like idler gears to transmit motion from the primary sun gear 128 and the primary internal ring gear 122 to the transfer internal ring gear 132 via the first axial portions 124a of set of planetary gear 124 in engagement with both the primary sun gear 128 and the primary internal ring gear 122 and the second axial portions 124b of set of planetary gear 124 in engagement with the transfer internal ring gear 132.

[00055] According to various embodiments, simultaneously providing the first motive power input (or the first rotary input) to rotate the primary sun gear 128 and providing the second motive power input (or the second rotary input) to rotate the primary internal ring gear 122 for driving the set of planetary gears 124 may boost the torque and rotational speed of the set of planetary gears 124 (e.g. by summating the torque and rotational speed of the primary sun gear 128 and the primary internal ring gear 122) so as to enhance the power output for driving the transfer internal ring gear 132. Further, according to various embodiments, the dual-input transmission assembly 110 having the planetary-gear-train- zone 120 and the pinions-and-internal-gear-set-zone 130 interconnected by the common set of planetary gears 124 may allow seamless switching between using one and both of the two independent separate input sources or prime movers (e.g. the engine and the electric motor). For example, the dual-input transmission assembly 110 may seamlessly switch, without causing a break or stoppage of the output rotation of the dual-input transmission assembly 110, from receiving only the first motive power input (or the first rotary input) at the primary sun gear 128 to receiving both the first motive power input (or the first rotary input) at the primary sun gear 128 and the second motive power input (or the second rotary input) at the primary internal ring gear 122 via simply activating the second prime mover and disengaging the planet carrier brake 125, or from receiving only the second motive power input (or the second rotary input) at the primary internal ring gear 122 to receiving both the first motive power input (or the first rotary input) at the primary sun gear 128 and the second motive power input (or the second rotary input) at the primary internal ring gear 122 via simply activating the first prime mover, or from receiving both the first motive power input (or the first rotary input) at the primary sun gear 128 and the second motive power input (or the second rotary input) at the primary internal ring gear 122 to receiving only the first motive power input (or the first rotary input) at the primary sun gear 128 via deactivating the second prime mover and engaging the planet carrier brake 125, or from receiving both the first motive power input (or the first rotary input) at the primary sun gear 128 and the second motive power input (or the second rotary input) at the primary internal ring gear 122 to receiving only the second motive power input (or the second rotary input) at the primary internal ring gear 122 via deactivating the first prime mover.

[00056] According to various embodiments, the dual-input transmission assembly 110 may include a transfer shaft 138. According to various embodiments, the transfer shaft 138 may be extending longitudinally from the primary sun gear 128 in an integral manner along the central rotational axis 112 in a direction from the primary internal ring gear 122 towards and through the transfer internal ring gear 132 so as to be rotated together with the primary sun gear 128. Accordingly, the transfer shaft 138 may be integral with the primary sun gear 128 so as to be rotated together in a synchronized manner (at a same time and speed) about the central rotational axis 112. For example, the transfer shaft 138 may be integrally connected or joined or welded to the primary sun gear 128 to form a single structural whole or single unit. As another example, the transfer shaft 138 may be integrally molded or cast with the primary sun gear 128 to form as a single piece. As yet another example, the transfer shaft 138 may be integrally formed with the primary sun gear 128, for example machined from a single block of material, as a single piece. Hence, the transfer shaft 128 may be rotated together with the primary sun gear 128 when the first motive power input (or the first rotary input) is provided to the primary sun gear 128 by the first prime mover (e.g. the engine). Further, the integral unit having the primary sun gear 128 and the transfer shaft 138 may be oriented such that the primary sun gear 128 may be within the planetary-gear-train- zone 120 while the transfer shaft 138 may be within the pinions-and-internal-gear-set-zone 130. Accordingly, the integral unit having the primary sun gear 128 and the transfer shaft 138 may be extending along the central rotational axis 112 parallel and alongside each planetary gear 124. According to various embodiments, the primary sun gear 128 may be in engagement with the first axial portion 124a of each planetary gear 124 while the transfer shaft 138 may be parallel and alongside the second axial portion 124b of each planetary gear 124 in a non-contact manner. Accordingly, the second axial portions 124b of the set of planetary gears 124 may be radially spaced from the transfer shaft 138. Hence, the transfer shaft 138 may be free from engaging the second axial portions 124b of the set of planetary gears 124. For example, a diameter of the transfer shaft 138 may be smaller than an outer diameter of an addendum circle of the primary sun gear 128 while an outer diameter of an addendum circle of the second axial portion 124b of each planetary gear 124 may be equal or smaller than an outer diameter of an addendum circle of the first axial portion 124a of each planetary gear 124.

[00057] According to various embodiments, the dual-input transmission assembly 110 may include an output shaft 158. According to various embodiments, the output shaft 158 may be extending longitudinally along the central rotational axis 112. Accordingly, the output shaft 158 may lie on the central rotational axis 112. According to various embodiments, the output shaft 158 may be after the pinions-and-internal-gear-set-zone 130. Accordingly, the pinions-and-intemal-gear-set-zone 130 may be between the output shaft 158 and the planetary-gear-train-zone 120.

[00058] According to various embodiments, the dual-input transmission assembly 110 may include a clutch mechanism 140 disposed between the pinions-and-internal-gear-set- zone 130 and the output shaft 158. Accordingly, the clutch mechanism 140 may connect the pinions-and-internal-gear-set-zone 130 to the output shaft 158.

[00059] According to various embodiments, the clutch mechanism 140 between the pinions-and-internal-gear-set-zone 130 and the output shaft 158 may be configured to selectively connect or disconnect the transfer shaft 138 to the output shaft 158 for selectively transmitting the rotation of the transfer shaft 138 to the output shaft 158. According to various embodiments, the clutch mechanism 140 may couple the transfer shaft 138 to the output shaft 158 and operable to selectively connect or disconnect the transfer shaft 138 to the output shaft 158. For example, when the clutch mechanism 140 connects the transfer shaft 138 to the output shaft 158, the first motive power input (or the first rotary input) from the first prime mover (e.g. the engine) may be directly transmitted to the output shaft 158 via the primary sun gear 128 and the transfer shaft 138 and through the clutch mechanism 140 to the output shaft 158.

[00060] According to various embodiments, the clutch mechanism 140 between the pinions-and-internal-gear-set-zone 130 and the output shaft 158 may be configured to selectively connect or disconnect the transfer internal ring gear 132 to the output shaft 158 for selectively transmitting the rotation of the transfer internal ring gear 132 to the output shaft 158. According to various embodiments, the clutch mechanism 140 may couple the transfer internal ring gear 132 to the output shaft 158 and operable to selectively connect or disconnect the transfer internal ring gear 132 to the output shaft 158. For example, when the clutch mechanism 140 connects the transfer internal ring gear 132 to the output shaft 158, the first motive power input (or the first rotary input) from the first prime mover (e.g. the engine) may be transmitted to the output shaft 158 via the primary sun gear 128 to the set of planetary gears 124 with the planet carrier 126 stationary, from the set of planetary gears 124 to the transfer internal ring gear 132, and from the transfer internal ring gear 132 to the output shaft 158 through the clutch mechanism 140. As another example, when the clutch mechanism 140 connects the transfer internal ring gear 132 to the output shaft 158, the second motive power input (or the second rotary input) from the second prime mover (e.g. the electric motor) may be transmitted to the output shaft 158 via the primary internal ring gear 122 to the set of planetary gears 124, from the set of planetary gears 124 to the transfer internal ring gear 132, and from the transfer internal ring gear 132 to the output shaft 158 through the clutch mechanism 140. As yet another example, when the clutch mechanism 140 connects the transfer internal ring gear 132 to the output shaft 158, counter-rotating the primary sun gear 128 and the primary internal ring gear 122 by the combined first and second motive power inputs (or the combined first second rotary inputs) from the first and second prime movers (e.g. the engine and the electric motor) may transmit a resultant rotation to the output shaft 158 via the counter-rotation between the primary internal ring gear 122 and the primary sun gear 128 to the set of planetary gears 124, from the set of planetary gears 124 to the transfer internal ring gear 132, and from the transfer internal ring gear 132 to the output shaft 158 through the clutch mechanism 140.

[00061] According to various embodiments, the clutch mechanism 140 between the pinions-and-internal-gear-set-zone 130 and the output shaft 158 may be configured to couple the transfer internal ring gear 132 or the transfer shaft 138 to the output shaft 158 for transmitting the rotation of the transfer internal ring gear 132 or the transfer shaft 138 to the output shaft 158. According to various embodiments, the clutch mechanism 140 may from a clutch coupling to connect both the transfer shaft 138 and the transfer internal ring gear 132 to the output shaft 158 and operable to selectively connect or disconnect the transfer shaft 138 or the transfer internal ring gear 132 to the output shaft 158. For example, when the clutch mechanism 140 connects the transfer shaft 138 to the output shaft 158, the first motive power input (or the first rotary input) from the first prime mover (e.g. the engine) may be directly transmitted to the output shaft 158 via the primary sun gear 128 and the transfer shaft 138 and through the clutch mechanism 140 to the output shaft 158. For example, when the clutch mechanism 140 connects the transfer internal ring gear 132 to the output shaft 158, the second motive power input (or the second rotary input) from the second prime mover (e.g. the electric motor) may be transmitted to the output shaft 158 via the primary internal ring gear 122 to the set of planetary gears 124, from the set of planetary gears 124 to the transfer internal ring gear 132, and from the transfer internal ring gear 132 to the output shaft 158 through the clutch mechanism 140. As another example, when the clutch mechanism 140 connects the transfer internal ring gear 132 to the output shaft 158, counter-rotating the primary sun gear 128 and the primary internal ring gear 122 by the combined first and second motive power inputs (or the combined first second rotary inputs) from the first and second prime movers (e.g. the engine and the electric motor) may transmit a resultant rotation to the output shaft 158 via the counter-rotation between the primary internal ring gear 122 and the primary sun gear 128 to the set of planetary gears 124, from the set of planetary gears 124 to the transfer internal ring gear 132, and from the transfer internal ring gear 132 to the output shaft 158 through the clutch mechanism 140.

[00062] According to various embodiments, the dual-input transmission assembly 110 may include an output ring gear 152 surrounding the output shaft 158 in a coaxial manner. Accordingly, the output shaft 158 and the output ring gear 152 may be in a concentric arrangement with respect to the central rotational axis 112, whereby the output ring gear 152 may surround a circumference of the output shaft 158 and may be radially spaced from the output shaft 158. Hence, the output shaft 158 and the output ring gear 152 may be independent of each other and not in contact with each other. Thus, each of the output shaft 158 and the output ring gear 152 may be independently rotatable about the central rotational axis 112. According to various embodiments, the output ring gear 152 may be an internal ring gear or an external ring gear. According to various embodiments, the output shaft 158 and the output ring gear 152 may form an output zone 150.

[00063] According to various embodiments, the clutch mechanism 140 may be disposed between the pinions-and-internal-gear-set-zone 130 and the output zone 150. Accordingly, the clutch mechanism 140 may connect the pinions-and-internal-gear-set-zone 130 to the output zone 150.

[00064] According to various embodiments, the clutch mechanism 140 between the pinions-and-internal-gear-set-zone 130 and the output zone 150 may be configured to selectively connect or disconnect the transfer internal ring gear 132 to one or both of the output shaft 158 and the output ring gear 152 for selectively transmitting the rotation of the transfer internal ring gear 132 to one or both of the output shaft 158 and the output ring gear 152. According to various embodiments, the clutch mechanism 140 may form a clutch coupling connecting the transfer internal ring gear 132 to both the output shaft 158 and the output ring gear 152, and operable to selectively connect or disconnect the transfer internal ring gear 132 to one or both of the output shaft 158 and the output ring gear 152. For example, when the clutch mechanism 140 connects the transfer internal ring gear 132 to the output shaft 158 or the output ring gear 152 or both, the first motive power input (or the first rotary input) from the first prime mover (e.g. the engine) may be transmitted to the output shaft 158 or the output ring gear 152 or both via the primary sun gear 128 to the set of planetary gears 124 with the planet carrier 126 stationary, from the set of planetary gears 124 to the transfer internal ring gear 132, and from the transfer internal ring gear 132 to the output shaft 158 or the output ring gear 152 or both through the clutch mechanism 140. As another example, when the clutch mechanism 140 connects the transfer internal ring gear 132 to the output shaft 158 or the output ring gear 152 or both, the second motive power input (or the second rotary input) from the second prime mover (e.g. the electric motor) may be transmitted to the output shaft 158 or the output ring gear 152 or both via the primary internal ring gear 122 to the set of planetary gears 124, from the set of planetary gears 124 to the transfer internal ring gear 132, and from the transfer internal ring gear 132 to the output shaft 158 or the output ring gear 152 or both through the clutch mechanism 140. As yet another example, when the clutch mechanism 140 connects the transfer internal ring gear 132 to the output shaft 158 or the output ring gear 152 or both, counter-rotating the primary sun gear 128 and the primary internal ring gear 122 by the combined first and second motive power inputs (or the combined first second rotary inputs) from the first and second prime movers (e.g. the engine and the electric motor) may transmit a resultant rotation to the output shaft 158 or the output ring gear 152 or both via the counter-rotation between the primary internal ring gear 122 and the primary sun gear 128 to the set of planetary gears 124, from the set of planetary gears 124 to the transfer internal ring gear 132, and from the transfer internal ring gear 132 to the output shaft 158 or the output ring gear 152 or both through the clutch mechanism 140.

[00065] According to various embodiments, the clutch mechanism 140 between the pinions-and-internal-gear-set-zone 130 and the output zone 150 may be configured to selectively couple the transfer internal ring gear 132 or the transfer shaft 138 to one or both of the output shaft 158 and the output ring gear 152 for selectively transmitting the rotation of the transfer internal ring gear 132 or the transfer shaft 138 to one or both of the output shaft 158 and the output ring gear 152. According to various embodiments, the clutch mechanism 140 may interconnect the pinions-and-internal-gear-set-zone 130 and the output zone 150 so as to form a clutch coupling connecting both the transfer internal ring gear 132 and the transfer shaft 138 to both the output shaft 158 and the output ring gear 152, and operable to selectively connect or disconnect one of the transfer internal ring gear 132 or the transfer shaft 138 to one or both of the output shaft 158 and the output ring gear 152. [00066] For example, when the clutch mechanism 140 connects the transfer shaft 138 to the output shaft 158, the first motive power input (or the first rotary input) from the first prime mover (e.g. the engine) may be directly transmitted to the output shaft 158 via the primary sun gear 128 and the transfer shaft 138 and through the clutch mechanism 140 to the output shaft 158. As another example, when the clutch mechanism 140 connects the transfer shaft 138 to the output ring gear 152, the first motive power input (or the first rotary input) from the first prime mover (e.g. the engine) may be directly transmitted to the output ring gear 152 via the primary sun gear 128 and the transfer shaft 138 and through the clutch mechanism 140 to the output ring gear 152. As yet another example, when the clutch mechanism 140 connects the transfer shaft 138 to both the output shaft 158 and the output ring gear 152, the first motive power input (or the first rotary input) from the first prime mover (e.g. the engine) may be directly transmitted to the output shaft 158 and the output ring gear 152 via the primary sun gear 128 and the transfer shaft 138, and through the clutch mechanism 140 to both the output shaft 158 and the output ring gear 152.

[00067] For example, when the clutch mechanism 140 connects the transfer internal ring gear 132 to the output shaft 158, the second motive power input (or the second rotary input) from the second prime mover (e.g. the electric motor) may be transmitted to the output shaft 158 via the primary internal ring gear 122 to the set of planetary gears 124, from the set of planetary gears 124 to the transfer internal ring gear 132, and from the transfer internal ring gear 132 to the output shaft 158 through the clutch mechanism 140. As another example, when the clutch mechanism 140 connects the transfer internal ring gear 132 to the output shaft 158, counter-rotating the primary sun gear 128 and the primary internal ring gear 122 by the combined first and second motive power inputs (or the combined first second rotary inputs) from the first and second prime movers (e.g. the engine and the electric motor) may transmit a resultant rotation to the output shaft 158 via the counter-rotation between the primary internal ring gear 122 and the primary sun gear 128 to the set of planetary gears 124, from the set of planetary gears 124 to the transfer internal ring gear 132, and from the transfer internal ring gear 132 to the output shaft 158 through the clutch mechanism 140. [00068] For example, when the clutch mechanism 140 connects the transfer internal ring gear 132 to the output ring gear 152 or both the output shaft 158 and the output ring gear 152, the first motive power input (or the first rotary input) from the first prime mover (e.g. the engine) may be transmitted to the output ring gear 152 or both the output shaft 158 and the output ring gear 152 via the primary sun gear 128 to the set of planetary gears 124 with the planet carrier 126 stationary, from the set of planetary gears 124 to the transfer internal ring gear 132, and from the transfer internal ring gear 132 to the output ring gear 152 or both the output shaft 158 and the output ring gear 152 through the clutch mechanism 140. As another example, when the clutch mechanism 140 connects the transfer internal ring gear 132 to the output ring gear 152 or both the output shaft 158 and the output ring gear 152, the second motive power input (or the second rotary input) from the second prime mover (e.g. the electric motor) may be transmitted to the output ring gear 152 or both the output shaft 158 and the output ring gear 152 via the primary internal ring gear 122 to the set of planetary gears 124, from the set of planetary gears 124 to the transfer internal ring gear 132, and from the transfer internal ring gear 132 to the output ring gear 152 or both the output shaft 158 and the output ring gear 152 through the clutch mechanism 140. As yet another example, when the clutch mechanism 140 connects the transfer internal ring gear 132 to the output ring gear 152 or both the output shaft 158 and the output ring gear 152, counter rotating the primary sun gear 128 and the primary internal ring gear 122 by the combined first and second motive power inputs (or the combined first second rotary inputs) from the first and second prime movers (e.g. the engine and the electric motor) may transmit a resultant rotation to the output ring gear 152 or both the output shaft 158 and the output ring gear 152 via the counter-rotation between the primary internal ring gear 122 and the primary sun gear 128 to the set of planetary gears 124, from the set of planetary gears 124 to the transfer internal ring gear 132, and from the transfer internal ring gear 132 to the output ring gear 152 or both the output shaft 158 and the output ring gear 152 through the clutch mechanism 140. [00069] According to various embodiments, the clutch mechanism 140 may include a first set of clutch elements 142, 144 and a second set of clutch elements 146, 148. According to various embodiments, the first set of clutch elements 142, 144 may be for connecting to one or both of the transfer internal ring gear 132 and the transfer shaft 138. According to various embodiments, the second set of clutch elements 146, 148 may be for connecting to one or both of the output shaft 158 and the output ring gear 152. According to various embodiments, the first set of clutch elements 142, 144 and the second set of clutch elements 146, 148 may be interconnected in a manner so as to be rotatable together in a synchronized manner (i.e. at the same time and same speed) about the central rotational axis 112. Accordingly, the first set of clutch elements 142, 144 and the second set of clutch elements 146, 148 may be interlocked to each other in the circumferential direction so as to be non-movable relative to each other in the circumferential direction. Hence, a rotation about the central rotational axis 112 impart to the first set of clutch elements 142, 144 may result in the second set of clutch elements 146, 148 rotating together in a synchronized manner (i.e. at the same time and same speed).

[00070] According to various embodiments, the first set of clutch elements 142, 144 may include a transfer-shaft-engagement-clutch-element 142. According to various embodiments, the transfer-shaft-engagement-clutch-element 142 may be movable along the central rotational axis 112 towards and away from the transfer shaft 138 for engaging and disengaging with the transfer shaft 138. Accordingly, the transfer-shaft-engagement-clutch- element 142 may move towards and engage the transfer shaft 138 such that the rotation of the transfer shaft 138 may be transmitted to rotate the first set of clutch elements 142, 144. Further, the transfer-shaft-engagement-clutch-element 142 may move away and disengage from the transfer shaft 138 such that the rotation of the transfer shaft 138 may no longer be transmitted to the first set of clutch elements 142, 144. According to various embodiments, the transfer- shaft-engagement-clutch-element 142 may engage the transfer shaft 138 via friction engagement.

[00071] According to various embodiments, the first set of clutch elements 142, 144 may include a transfer-ring-gear-engagement-clutch-element 144. According to various embodiments, the transfer-ring-gear-engagement-clutch-element 144 may be movable along the central rotational axis 112 towards and away from the transfer internal ring gear 132 for engaging and disengaging with the transfer internal ring gear 132. Accordingly, the transfer-ring-gear-engagement-clutch-element 144 may move towards and engage the transfer internal ring gear 132 such that the rotation of the transfer internal ring gear 132 may be transmitted to rotate the first set of clutch elements 142, 144. Further, the transfer- ring-gear-engagement-clutch-element 144 may move away and disengage from the transfer internal ring gear 132 such that the rotation of the transfer internal ring gear 132 may no longer be transmitted to the first set of clutch elements 142, 144. According to various embodiments, the transfer-ring-gear-engagement-clutch-element 144 may engage the transfer internal ring gear 132 via friction engagement.

[00072] According to various embodiments, the transfer-shaft-engagement-clutch- element 142 and the transfer-ring-gear-engagement-clutch-element 144 may be interconnected in a manner so as to be rotatable together in a synchronized manner (i.e. at the same time and same speed) about the central rotational axis 112. Accordingly, the transfer- shaft-engagement-clutch-element 142 and the transfer-ring-gear-engagement- clutch-element 144 may be interlocked to each other in the circumferential direction so as to be non-movable relative to each other in the circumferential direction. Hence, a rotation about the central rotational axis 112 impart to either the transfer-shaft-engagement-clutch- element 142 or the transfer-ring-gear-engagement-clutch-element 144 may result in the first set of clutch elements 142, 144 rotating together in a synchronized manner (i.e. at the same time and same speed).

[00073] According to various embodiments, the transfer-shaft-engagement-clutch- element 142 and the transfer-ring-gear-engagement-clutch-element 144 may be movable relative to each other in a telescopic manner. According to various embodiments, the transfer-ring-gear-engagement-clutch-element 144 may be movable relative to the transfer- shaft-engagement-clutch-element 142 telescopically so as to extendable away from the transfer- shaft-engagement-clutch-element 142 to engage with the transfer internal ring gear 132 and to retract back towards the transfer-shaft-engagement-clutch-element 142 to disengage from the transfer internal ring gear 132. According to various embodiments, when the transfer-ring-gear-engagement-clutch-element 144 is retracted relative to the transfer- shaft-engagement-clutch-element 142, the first set of clutch elements 142, 144 may be movable together along the central rotational axis 112 towards and away from the transfer shaft 138 for engaging and disengaging with the transfer shaft 138.

[00074] According to various embodiments, the second set of clutch elements 146, 148 may include an output-shaft-engagement-clutch-element 146. According to various embodiments, the output-shaft-engagement-clutch-element 146 may be movable along the central rotational axis 112 towards and away from the output shaft 158 for engaging and disengaging with the output shaft 158. Accordingly, output-shaft-engagement-clutch- element 146 may move towards and engage the output shaft 158 such that a rotation of the second set of clutch elements 146, 146 may be transmitted to the output shaft 158. Further, the output- shaft-engagement-clutch-element 146 may move away and disengage from the output shaft 158 such that the rotation of the second set of clutch elements 146, 146 may no longer be transmitted to the output shaft 158. According to various embodiments, the output- shaft-engagement-clutch-element 146 may engage the output shaft 158 via friction engagement.

[00075] According to various embodiments, the second set of clutch elements 146, 148 may include an output-ring-gear-engagement-clutch-element 148. According to various embodiments, the output-ring-gear-engagement-clutch-element 148 may be movable along the central rotational axis 112 towards and away from the output ring gear 152 for engaging and disengaging with the output ring gear 152. Accordingly, the output-ring-gear- engagement-clutch-element 148 may move towards and engage the output ring gear 152 such that a rotation of the second set of clutch elements 146, 146 may be transmitted to the output ring gear 152. Further, the output-ring-gear-engagement-clutch-element 148 may move away and disengage from the output ring gear 152 such that the rotation of the second set of clutch elements 146, 146 may no longer be transmitted to the output ring gear 152. According to various embodiments, the output-ring-gear-engagement-clutch-element 148 may engage the output ring gear 152 via friction engagement.

[00076] According to various embodiments, the output-shaft-engagement-clutch-element 146 and the output-ring-gear-engagement-clutch-element 148 may be interconnected in a manner so as to be rotatable together in a synchronized manner (i.e. at the same time and same speed) about the central rotational axis 112. Accordingly, the output-shaft- engagement-clutch-element 146 and the output-ring-gear-engagement-clutch-element 148 may be interlocked to each other in the circumferential direction so as to be non-movable relative to each other in the circumferential direction. Hence, rotating either the output-shaft- engagement-clutch-element 146 or the output-ring-gear-engagement-clutch-element 148 about the central rotational axis 112 may result in the second set of clutch elements 146, 148 rotating together in a synchronized manner (i.e. at the same time and same speed).

[00077] According to various embodiments, the output-shaft-engagement-clutch-element 146 and the output-ring-gear-engagement-clutch-element 148 may be movable relative to each other in a telescopic manner. According to various embodiments, the output-ring-gear- engagement-clutch-element 148 may be movable relative to the output-shaft-engagement- clutch-element 146 telescopically so as to extendable away from the output-shaft- engagement-clutch-element 146 to engage with the output ring gear 152 and to retract back towards the output-shaft-engagement-clutch-element 146 to disengage from the output ring gear 152. According to various embodiments, when the output-ring-gear-engagement- clutch-element 148 is retracted relative to the output-shaft-engagement-clutch-element 146, the second set of clutch elements 146, 148 may be movable together along the central rotational axis 112 towards and away from the output shaft 158 for engaging and disengaging with the output shaft 158.

[00078] According to various embodiments, the transfer-shaft-engagement-clutch- element 142 and the output-shaft-engagement-clutch-element 146 may be interconnected in a manner so as to be rotatable together in a synchronized manner (i.e. at the same time and same speed) about the central rotational axis 112. Accordingly, the transfer- shaft- engagement-clutch-element 142 and the output-shaft-engagement-clutch-element 146 may be interlocked to each other in the circumferential direction so as to be non-movable relative to each other in the circumferential direction. Hence, rotating the transfer-shaft-engagement- clutch-element 142 may result in the output-shaft-engagement-clutch-element 146 rotating together in a synchronized manner (i.e. at the same time and same speed).

[00079] According to various embodiments, the transfer-shaft-engagement-clutch- element 142 and the output- shaft-engagement-clutch-element 146 may be movable relative to each other in a telescopic manner. According to various embodiments, the transfer- shaft- engagement-clutch-element 142 may be movable away from the output-shaft-engagement- clutch-element 146 telescopically so as to extend away from the output-shaft-engagement- clutch-element 146 to engage with the transfer shaft 138 and to retract the transfer-shaft- engagement-clutch-element 142 back towards the output-shaft-engagement-clutch-element 144 to disengage from the transfer shaft 138. According to various embodiments, the output- shaft-engagement-clutch-element 146 may be movable away from the transfer-shaft- engagement-clutch-element 142 telescopically so as to extend the output-shaft-engagement- clutch-element 146 away from the transfer- shaft-engagement-clutch-element 142 to engage with the output shaft 158 and to retract the output-shaft-engagement-clutch-element 146 back towards the transfer-shaft-engagement-clutch-element 142 to disengage from the output shaft 158. According to various embodiments, the transfer-shaft-engagement-clutch- element 142 and the output- shaft-engagement-clutch-element 146 may be movable away from each other telescopically to extend away from each other such that the transfer-shaft- engagement-clutch-element 142 may engage the transfer shaft 132 and the output-shaft- engagement-clutch-element 146 may engage the output shaft 158, and to retract towards each other such that the transfer- shaft-engagement-clutch-element 142 may disengage from the transfer shaft 138 and the output-shaft-engagement-clutch-element 146 may disengage from the output shaft 158.

[00080] According to various embodiments, the dual-input transmission assembly 110 may include an input shaft 118. According to various embodiments, the input shaft 118 may be extending from the primary sun gear 128 in a direction opposite and away from the transfer internal ring gear 132 in an integral manner along the central rotational axis 112. Accordingly, the input shaft 118 may be integral with the primary sun gear 128 so as to be rotated together in a synchronized manner (at a same time and speed) about the central rotational axis 112. For example, the input shaft 118 may be integrally connected or joined or welded to the primary sun gear 128 to form a single structural whole or single unit. As another example, the input shaft 118 may be integrally molded or cast with the primary sun gear 128 to form as a single piece. As yet another example, the input shaft 118 may be integrally formed with the primary sun gear 128, for example machined from a single block of material, as a single piece. Further, the input shaft 118 may be extending from the primary sun gear 128 in a direction opposite and away from the transfer shaft 138. Hence, the input shaft 118 and the transfer shaft 138 may be extending from two opposite directions from the primary sun gear 128 and along the central rotational axis 112. According to various embodiments, the input shaft 118 may be leading from the first prime mover (e.g. the engine) such that the first prime mover may drive the input shaft 118 to rotate so as to provide the first motive power input (or the first rotary input) to the primary sun gear 128. For example, the input shaft 118 may be a drive shaft delivering power and rotation from the first prime mover (e.g. the engine). Accordingly, the input shaft 118 may rotate the primary sun gear 128 when the input shaft 118 is being driven by the first prime mover (e.g. the engine) to rotate.

[00081] FIG. ID shows the dual-input transmission assembly 110 in operation to drive the output shaft 158 with the first motive power input (or the first rotary input) provided to the primary sun gear 128 according to various embodiments. As shown, the transfer-shaft- engagement-clutch-element 142 and the output-shaft-engagement-clutch-element 146 may be extended away from each other telescopically such that the transfer-shaft-engagement- clutch-element 142 may engage the transfer shaft 132 and the output-shaft-engagement- clutch-element 146 may engage the output shaft 158. The transfer-ring-gear-engagement- clutch-element 144 may be retracted with respect to the transfer-shaft-engagement-clutch- element 142 and the output-ring-gear-engagement-clutch-element 148 may be retracted with respect to the output- shaft-engagement-clutch-element 146. Accordingly, with the first motive power input (or the first rotary input) provided to the primary sun gear 128, the transfer shaft 132 rotating together with the primary sun gear 128 may rotate the transfer- shaft-engagement-clutch-element 142 so as to rotate the output- shaft-engagement-clutch- element 146 for driving the output shaft 158 to rotate.

[00082] FIG. IE shows the dual-input transmission assembly 110 in operation to drive the output ring gear 152 with the first motive power input (or the first rotary input) provided to the primary sun gear 128 according to various embodiments. As shown, the transfer-shaft- engagement-clutch-element 142 may engage the transfer shaft 132 and output-ring-gear- engagement-clutch-element 148 may be extended relative to the output- shaft-engagement- clutch-element 146 to engage the output ring gear 152. The transfer-ring-gear-engagement- clutch-element 144 may be retracted with respect to the transfer-shaft-engagement-clutch- element 142. Accordingly, with the first motive power input (or the first rotary input) provided to the primary sun gear 128, the transfer shaft 132 rotating together with the primary sun gear 128 may rotate the transfer-shaft-engagement-clutch-element 142 so as to rotate the output-ring-gear-engagement-clutch-element 148 for driving the output ring gear 152 to rotate.

[00083] FIG. IF shows the dual-input transmission assembly 110 in operation to drive the output ring gear 152 with the second motive power input (or the second rotary input) provided to the primary internal ring gear 122 according to various embodiments. As shown, the transfer-ring-gear-engagement-clutch-element 144 may be extended away from the transfer-shaft-engagement-clutch-element 142 to engage the transfer internal ring gear 132 and the output-ring-gear-engagement-clutch-element 148 may be extended away from the output-shaft-engagement-clutch-element 146 to engage the output ring gear 152. Accordingly, with the second motive power input (or the second rotary input) provided to the primary internal ring gear 122, the primary internal ring gear 122 may drive the set of planetary gears 124 for rotating the transfer internal ring gear 132, the transfer internal ring gear 132 may rotate the transfer-ring-gear-engagement-clutch-element 144 so as to rotate the output-ring-gear-engagement-clutch-element 148 for driving the output ring gear 152. [00084] FIG. 1G shows the dual-input transmission assembly 110 in operation to drive the output shaft 158 with the second motive power input (or the second rotary input) provided to the primary internal ring gear 122 according to various embodiments. As shown, the transfer-ring-gear-engagement-clutch-element 144 may be extended away from the transfer-shaft-engagement-clutch-element 142 to engage the transfer internal ring gear 132 and output-shaft-engagement-clutch-element 146 may engage the output shaft 158. The output-ring-gear-engagement-clutch-element 148 may be retracted with respect to the output-shaft-engagement-clutch-element 146. Accordingly, with the second motive power input (or the second rotary input) provided to the primary internal ring gear 122, the primary internal ring gear 122 may drive the set of planetary gears 124 for rotating the transfer internal ring gear 132, the transfer internal ring gear 132 may rotate the transfer-ring-gear- engagement-clutch-element 144 so as to rotate the output- shaft-engagement-clutch-element 146 for driving the output shaft 158.

[00085] FIG. 1H shows the dual-input transmission assembly 110 in operation to drive the output shaft 158 with the first motive power input (or the first rotary input) provided to the primary sun gear 128 and the second motive power input (or the second rotary input) provided to the primary internal ring gear 122 simultaneously according to various embodiments. The first motive power input (or the first rotary input) and the second motive power input (or the second rotary input) may be counter-rotating. As shown, the transfer- ring-gear-engagement-clutch-element 144 may be extended away from the transfer-shaft- engagement-clutch-element 142 to engage the transfer internal ring gear 132 and output- shaft-engagement-clutch-element 146 may engage the output shaft 158. The output-ring- gear-engagement-clutch-element 148 may be retracted with respect to the output-shaft- engagement-clutch-element 146. Accordingly, with the counter-rotating first motive power input (or the first rotary input) and second motive power input (or the second rotary input) provided to the primary sun gear 128 and the primary internal ring gear 122 respectively, the counter-rotation of the primary sun gear 128 and the primary internal ring gear 122 may drive the set of planetary gears 124 for rotating the transfer internal ring gear 132, the transfer internal ring gear 132 may rotate the transfer-ring-gear-engagement-clutch-element 144 so as to rotate the output- shaft-engagement-clutch-element 146 for driving the output shaft 158.

[00086] FIG. II shows the dual-input transmission assembly 110 in operation to drive the output ring gear 152 with the first motive power input (or the first rotary input) provided to the primary sun gear 128 and the second motive power input (or the second rotary input) provided to the primary internal ring gear 122 simultaneously according to various embodiments. The first motive power input (or the first rotary input) and the second motive power input (or the second rotary input) may be counter-rotating. As shown, the transfer- ring-gear-engagement-clutch-element 144 may be extended away from the transfer-shaft- engagement-clutch-element 142 to engage the transfer internal ring gear 132 and the output- ring-gear-engagement-clutch-element 148 may be extended away from the output-shaft- engagement-clutch-element 146 to engage the output ring gear 152. Accordingly, with the counter-rotating first motive power input (or the first rotary input) and second motive power input (or the second rotary input) provided to the primary sun gear 128 and the primary internal ring gear 122 respectively, the counter-rotation of the primary sun gear 128 and the primary internal ring gear 122 may drive the set of planetary gears 124 for rotating the transfer internal ring gear 132, the transfer internal ring gear 132 may rotate the transfer- ring-gear-engagement-clutch-element 144 so as to rotate the output-ring-gear-engagement- clutch-element 148 for driving the output ring gear 152.

[00087] FIG. 1 J shows a schematic drawing of a powertrain 100 for a vehicle, for example a vehicle capable of land and aerial transportation according to various embodiments. According to various embodiments, the powertrain 100 may include the dual input transmission assembly 110. According to various embodiments, the powertrain 100 may include the first prime mover 102 (e.g. the engine) and the second prime mover 104 (e.g. the electric motor). According to various embodiments, the first prime mover 102 (e.g. the engine) and the second prime mover 104 (e.g. the electric motor) may be independent of each other. Accordingly, each of the first prime mover 102 (e.g. the engine) and the second prime mover 104 (e.g. the electric motor) may be independently activated or de-activated. According to various embodiments, the powertrain 100 may be operable to simultaneously activate both the first prime mover 102 (e.g. the engine) and the second prime mover 104 (e.g. the electric motor), or to activate either one of the first prime mover 102 (e.g. the engine) and the second prime mover 104 (e.g. the electric motor).

[00088] According to various embodiments, the first prime mover 102 (e.g. the engine) may be connected to the primary sun gear 128 of the dual input transmission assembly 110 for driving the primary sun gear 128 to rotate. For example, the first prime mover 102 (e.g. the engine) may be directly coupled to the input shaft 118 so as to be connected to the primary sun gear 128. According to various embodiments, the second prime mover 104 (e.g. the electric motor) may be connected to the input internal ring 122 gear of the dual input transmission assembly 110 for driving the primary internal ring gear 122 to rotate. For example, the second prime mover 104 (e.g. the electric motor) may be connected to the input internal ring 122 via a chain or belt drive.

[00089] According to various embodiments, the powertrain 100 may include a controller 105. According to various embodiments, the controller 105 may be connected to the planet carrier brake 125 of the dual input transmission assembly 110 and the second prime mover 104 (e.g. the electric motor). According to various embodiments, the controller 105 may be configured to engage the planet carrier brake 125 in response to the second prime mover 104 (e.g. the electric motor) being deactivated to cease providing the second motive power input (or the second rotary input) to the primary internal ring gear 122 and to disengage the planet carrier brake 125 in response to the second prime mover 104 (e.g. the electric motor) being activated to provide the second motive power input (or the second rotary input) to the primary internal ring gear 122.

[00090] According to various embodiments, the controller 105 may be further configured to control and regulate the second prime mover 104 (e.g. the electric motor) for providing the second motive power input (or the second rotary input) to the primary internal ring gear 122 when the powertrain 100 is operated to activate both the first prime mover 102 (e.g. the engine) and the second prime mover 104 (e.g. the electric motor) for providing the counter rotating first motive power input (or the first rotary input) and second motive power input (or the second rotary input) to the primary sun gear 128 and the primary internal ring gear 122 respectively. According to various embodiments, the controller 105 may be configured to control and regulate the second prime mover 104 (e.g. the electric motor) so as to optimise the second motive power input (or the second rotary input) provided to the primary internal ring gear 122 taking in to account the first motive power input (or the first rotary input) provided by the first prime mover 102 (e.g. the engine) for optimising the counter-rotation of the primary sun gear 128 and the primary internal ring gear 122 to drive the set of planetary gears 124.

[00091] In various embodiments, the "controller 105" may be understood as any kind of a logic implementing entity, which may be special purpose circuitry or a processor executing software stored in a memory, firmware, or any combination thereof. Thus, in an embodiment, the "controller 105" may be a hard- wired logic circuit or a programmable logic circuit such as a programmable processor, e.g. a microprocessor (e.g. a Complex Instruction Set Computer (CISC) processor or a Reduced Instruction Set Computer (RISC) processor). The "controller 105" may also be a processor executing software, e.g. any kind of computer program, e.g. a computer program using a virtual machine code such as e.g. Java. Any other kind of implementation of the respective functions which are described in more detail throughout may also be understood as the "controller 105" in accordance with various embodiments. In various embodiments, the “controller 105” may be part of a computing system or a controller or a microcontroller or any other system providing a processing capability. According to various embodiments, such systems may include a memory which is for example used in the processing carried out by the device or system. A memory used in the embodiments may be a volatile memory, for example a DRAM (Dynamic Random Access Memory) or a non-volatile memory, for example a PROM (Programmable Read Only Memory), an EPROM (Erasable PROM), EEPROM (Electrically Erasable PROM), or a flash memory, e.g., a floating gate memory, a charge trapping memory, an MRAM (Magneto-resistive Random Access Memory) or a PCRAM (Phase Change Random Access Memory).

[00092] According to various embodiments, the powertrain 100 may include a first propulsion unit 106 (e.g. a drive wheel) and a second propulsion unit 108 (e.g. an air propulsion unit). According to various embodiments, the first propulsion unit 106 (e.g. the drive wheel) may be connected to the output shaft 158 of the dual input transmission assembly 110. Accordingly, the output shaft 158 of the dual input transmission assembly 110 may drive the first propulsion unit 106 (e.g. rotate the drive wheel) for moving the vehicle. According to various embodiments, the second propulsion unit 108 (e.g. the air propulsion unit) may be connected to the output ring gear 152 of the dual input transmission assembly 110. Accordingly, the output ring gear 152 of the dual input transmission assembly 110 may drive the second propulsion unit 108 (e.g. drive the air propulsion unit) for moving the vehicle.

[00093] FIG. IK shows a schematic drawing of another powertrain 101 for a vehicle, for example a vehicle capable of land and aerial transportation according to various embodiments. According to various embodiments, the powertrain 101 of FIG. IK differ from the powertrain 100 of FIG. 1J in that the the first propulsion unit 106 (e.g. the drive wheel) may be connected to the output ring gear 152 of the dual input transmission assembly 110 and the second propulsion unit 108 (e.g. the air propulsion unit) may be connected to the output shaft 158 of the dual input transmission assembly 110.

[00094] FIG. 2A shows a schematic diagram of a dual-input transmission assembly 210 according to various embodiments. FIG. 2B shows a schematic exploded diagram of the dual-input transmission assembly 210 of FIG. 2A according to various embodiment. FIG. 2C shows a schematic cross-sectional diagram of the dual-input transmission assembly 210 of FIG. 2A according to various embodiments. According to various embodiments, the dual input transmission assembly 210 of FIG. 2A to FIG. 2C may include all the features and limitations of the dual-input transmission assembly 110 of FIG. 1A to FIG. 1C. According to various embodiments, the dual-input transmission assembly 210 of FIG. 2A to FIG. 2C may further include the following additional features and limitations. [00095] According to various embodiments, the dual-input transmission assembly 210 may further include a rear-output internal ring gear 262. According to various embodiments, the rear-output internal ring gear 262 may be arranged side-by-side to the primary internal ring gear 122 opposite the transfer internal ring gear 132 along the central rotational axis 112 in a coaxial manner and rotatable about the central rotational axis 112. Accordingly, the transfer internal ring gear 132, the primary internal ring gear 122 and the rear-output internal ring gear 262 may be arranged coaxially one after another along the central rotational axis 112 such that the primary internal ring gear 122 may be between the transfer internal ring gear 132 and the rear-output internal ring gear 262. Hence, the transfer internal ring gear 132 and the rear-output internal ring gear 262 may be on two opposite sides of the primary internal ring gear 122 along the central rotational axis 112. According to various embodiments, the central rotational axis 112 may be extending through or intersecting a centre of the rear-output internal ring gear 262 or passing through a centre point of an inner space 262a surrounded by the rear-output internal ring gear 262. Thus, the rear-output internal ring gear 262 may not be fixed and may be free to rotate about the central rotational axis 112. A radius of the rear-output internal ring gear 262 may be measured from the centre of the rear-output internal ring gear 262. Hence, the rear-output internal ring gear 262 may be rotated about an axis of the rear-output internal ring gear 262 from which the radius of the rear-output internal ring gear 262 is measured. Accordingly, the axis of the rear-output internal ring gear 262 may coincide with the central rotational axis 112.

[00096] According to various embodiments, the set of planetary gears 124 of the dual input transmission assembly 210 may respectively include a third axial portion 224d. According to various embodiments, each planetary gear 124 may include the third axial portion 224d. According to various embodiments, the third axial portion 224d may extend axially from the first axial portion 124a in a direction opposite the second axial portion 124b so as to extend to within the rear-output internal ring gear 262. Accordingly, the third axial portion 224d may extend along the axis of rotation of each planetary gear 124 from the first axial portion 124a to within the inner space 262a surrounded by the rear-output internal ring gear 262 such that the third axial portion 224d lies within the inner space 262a surrounded by the rear-output internal ring gear 262. According to various embodiments, each planetary gear 124 may extend from within the transfer internal ring gear 132, through the primary internal ring gear 122 and to within the rear-output internal ring gear 262. According to various embodiments, a total width (or axial length) of each planetary gear 124 along its axis of rotation may extend across the face width of the transfer internal ring gear 132, the face width of the primary internal ring gear 122 and a face width of the rear-output internal ring gear 262. According to various embodiments, the total width (or axial length) of each planetary gear 124 along its axis of rotation may be equal or greater than a combination of the face width of the transfer internal ring gear 132, the face width of the primary internal ring gear 122 and the face width of the rear-output internal ring gear 262. According to various embodiments, the first axial portion 124a of each planetary gear 124, the second axial portion 124b of each planetary gear 124 and the third axial potion 224d of each planetary gear 124 may be integral such that each planetary gear 124 may rotate as a single unit with the first axial portion 124a, the second axial portion 124b and the third axial portion 224d of each planetary gear 124 rotating together in unison.

[00097] According to various embodiments, the third axial portion 224d may be in engagement with the rear-output internal ring gear 262. Accordingly, the third axial portion 224d may mesh with the rear-output internal ring gear 262. According to various embodiments, the face width of the rear-output internal ring gear 262 may be equal to or less than an axial length of the third axial portion 224d of each planetary gear 124 such that the rear-output internal ring gear 262 may only mesh with the third axial portion 224d of each planetary gear 124.

[00098] According to various embodiments, the rear-output internal ring gear 262 and the third axial portions 224d of the set of planetary gears 124 may form a rear-pinions-and- intemal-gear-set-zone 260 without the primary sun gear 128 being in engagement or contact with the third axial portions 224d of the set of planetary gears 124, whereby the third axial portion 224d of each planetary gear 124 may serve as a pinion for engaging only the rear- output internal ring gear 262. According to various embodiments, the set of planetary gears 124 may be common to both the planetary-gear-train-zone 120, the pinions-and-internal- gear-set-zone 130 and the rear-pinions-and-internal-gear-set-zone 260. Accordingly, the set of planetary gears 124 may serve to transmit or transfer rotation generated from the planetary-gear-train-zone 120 to the rear-pinions-and-internal-gear-set-zone 260 for driving the rear-output internal ring gear 262. Hence, the set of planetary gears 124 may function like an idler gear to transmit motion from the planetary-gear-train-zone 120 to the rear- pinions-and-internal-gear-set-zone 260 so as to drive the rear-output internal ring gear 262. [00099] According to various embodiments, the third axial portions 224d of the set of planetary gears 124 may surround the input shaft 118, which extends from the primary sun gear 128 in a direction opposite the transfer shaft 138, in a non-contact manner. Accordingly, the third axial portions 224d of the set of planetary gears 124 may be radially spaced from the input shaft 118. Hence, the input shaft 118 may be free from engaging the third axial portions 224d of the set of planetary gears 124. For example, a diameter of the input shaft 118 may be smaller than an outer diameter of an addendum circle of the primary sun gear 128 while an outer diameter of an addendum circle of the third axial portion 224d of each planetary gear 124 may be equal or smaller than the outer diameter of the addendum circle of the first axial portion 124a of each planetary gear 124.

[000100] According to various embodiments, a gear ratio between the primary internal ring gear 122 and the first axial portion 124a of each planetary gear 124 may be different from a gear ratio between the rear-output internal ring gear 262 and the third axial portion 224d of each planetary gear 124. For example, a gear ratio between the primary internal ring gear 122 and the first axial portion 124a of each planetary gear 124 may be higher than a gear ratio between the rear-output internal ring gear 262 and the third axial portion 224d of each planetary gear 124. According to various embodiments, the first axial portion 124a of each planetary gear 124 and the third axial portion 224d of each planetary gear 124 may have different number of teeth and/or different diameter. Correspondingly, the primary internal ring gear 122 and the rear-output internal ring gear 262 may have different number of teeth and/or different diameter. For example, the first axial portion 124a of each planetary gear 124 may have a higher number of teeth (and/or a bigger diameter) than the third axial portion 224d of each planetary gear 124 while the primary internal ring gear 122 may have a higher number of teeth (and/or bigger diameter) than the rear-output internal ring gear 262 in a manner such that the gear ratio between the primary internal ring gear 122 and the first axial portion 124a of each planetary gear 124 may be higher than the gear ratio between the rear-output internal ring gear 262 and the third axial portion 224d of each planetary gear 124.

[000101] According to various embodiments, in the dual-input transmission assembly 210, when the primary sun gear 128 is receiving the first motive power input (or the first rotary input) from the first prime mover (e.g. the engine) with the planet carrier brake 125 engaged to lock the planet carrier 126, the set of planetary gears 124 may drive and rotate the rear- output internal ring gear 262 via the engagement between the third axial portion 224d of each planetary gear 124 and the rear-output internal ring gear 262 in addition to driving and rotating the transfer internal ring gear 132. Accordingly, the primary sun gear 128 may rotate and drive the set of planetary gears 124 to respectively rotate about their axes of rotation relative to the stationary planet carrier 126 via the engagement between the primary sun gear 128 and the first axial portions 124a of set of planetary gear 124. With the set of planetary gears 124 rotating about their axes of rotation relative to the stationary planet carrier 126, the second axial portions 124b of the set of planetary gear 124 in engagement with the transfer internal ring gear 132 may drive the transfer internal ring gear 132 while the third axial portions 224d of the set of planetary gear 124 in engagement with the rear-output internal ring gear 262 may drive the rear-output internal ring 262. Hence, the set of planetary gears 124 being common to the planetary-gear-train-zone 120, the pinions-and-internal- gear-set-zone 130, and the rear-pinions-and-intemal-gear-set-zone 260 may serve to transmit or transfer a rotation of the primary sun gear 128 of the planetary-gear-train-zone 120 (which is driven by the first motive power input or the first rotary input) to drive the transfer internal ring gear 132 of the pinions-and-internal-gear-set-zone 130 and the rear- output internal ring gear 262 of the rear-pinions-and-internal-gear-set-zone 260. Hence, the set of planetary gears 124 may function like idler gears to transmit rotary motion from the primary sun gear 128 to the transfer internal ring gear 132 and the rear-output internal ring gear 262, wherein the set of planetary gear 124 may be rotating about their axes of rotation in a synchronized manner (at the same time and speed) with each planetary gear 124 rotating as a single unit.

[000102] According to various embodiments, in the dual-input transmission assembly 210, when the primary internal ring gear 122 is receiving the second motive power input (or the second rotary input) from the second prime mover (e.g. the electric motor), the set of planetary gears 124 may drive and rotate the rear-output internal ring gear 262 via the engagement between the third axial portion 224d of each planetary gear 124 and the rear- output internal ring gear 262 in addition to driving and rotating the transfer internal ring gear 132. Accordingly, the primary internal ring gear 122 may rotate and drive the set of planetary gears 124, with the primary sun gear 128 locked and the planet carrier brake 125 disengaged, to respectively rotate about their axes of rotation relative to the planet carrier 126 and to revolve about the stationary primary sun gear 128 as the planet carrier 126 rotates about the central rotational axis 112 via the engagement between the primary internal ring gear 122 and the first axial portions 124a of set of the planetary gears 124. With the set of planetary gears 124 rotating about their axes of rotation and revolving about the stationary primary sun gear 128 together with the planet carrier 126 rotating about the central rotational axis 112, the second axial portions 124b of set of planetary gear 124 may drive the transfer internal ring gear 132 and the third axial portions 224d of the set of planetary gear 124 may drive the rear-output internal ring 262. Hence, the set of planetary gears 124 being common to the planetary-gear-train-zone 120, the pinions-and-internal-gear-set-zone 130, and the rear-pinions-and-internal-gear-set-zone 260 may serve to transmit or transfer a rotation of the primary internal ring gear 122 of the planetary-gear-train-zone 120 (which is driven by the second motive power input or the second rotary input) to drive the transfer internal ring gear 132 of the pinions-and-internal-gear-set-zone 130 and the rear-output internal ring gear 262 of the rear-pinions-and-internal-gear-set-zone 260. Hence, the set of planetary gears 124 may function like idler gears to transmit motion from the primary internal ring gear 122 to the transfer internal ring gear 132 and the rear-output internal ring gear 262.

[000103] According to various embodiments, in the dual-input transmission assembly 210, when the primary sun gear 128 and the primary internal ring gear 122 are counter-rotating with the planet carrier brake 125 disengaged, the counter-rotation between the primary sun gear 128 and the primary internal ring gear 122 may cause the set of planetary gears 124 to drive and rotate the rear-output internal ring gear 262 via the engagement between the third axial portion 224d of each planetary gear 124 and the rear-output internal ring gear 262 in addition to driving and rotating the transfer internal ring gear 132. Accordingly, the counter rotation between the primary sun gear 128 and the primary internal ring gear 122 may drive and rotate the set of planetary gears 124 such that the second axial portions 124b of set of planetary gear 124 may drive the transfer internal ring gear 132 and the third axial portions 224d of the set of planetary gear 124 may drive the rear-output internal ring 262. Hence, the set of planetary gears 124 being common to the planetary-gear-train-zone 120, the pinions- and-internal-gear-set-zone 130, and the rear-pinions-and-internal-gear-set-zone 260 may serve to transmit or transfer the combined rotary inputs of the primary sun gear 128 and the primary internal ring gear 122 of the planetary-gear- train-zone 120 to drive the transfer internal ring gear 132 of the pinions-and-intemal-gear-set-zone 130 and the rear-output internal ring gear 262 of the rear-pinions-and-internal-gear-set-zone 260. Hence, the set of planetary gears 124 may function like idler gears to transmit motion from the primary sun gear 128 and the primary internal ring gear 122 to the transfer internal ring gear 132 and the rear-output internal ring gear 262.

[000104] FIG. 2D shows the dual-input transmission assembly 210 in operation to drive the output shaft 158 and the rear-output internal ring gear 262 with the first motive power input (or the first rotary input) provided to the primary sun gear 128 according to various embodiments. As shown, the transfer- shaft-engagement-clutch-element 142 may engage the transfer shaft 132 and the output-shaft-engagement-clutch-element 146 may engage the output shaft 158. The transfer-ring-gear-engagement-clutch-element 144 may be retracted with respect to the transfer- shaft-engagement-clutch-element 142 and the output-ring-gear- engagement-clutch-element 148 may be retracted with respect to the output-shaft- engagement-clutch-element 146. Accordingly, with the first motive power input (or the first rotary input) provided to the primary sun gear 128, the transfer shaft 132 rotating together with the primary sun gear 128 may rotate the transfer-shaft-engagement-clutch-element 142 so as to rotate the output- shaft-engagement-clutch-element 146 for driving the output shaft 158 to rotate. Further, the primary sun gear 128 may rotate and drive the set of planetary gears 124, and the set of planetary gears 124 with the third axial portions 224d of the set of planetary gear 124 in engagement with the rear-output internal ring gear 262 may drive the rear-output internal ring 262.

[000105] FIG. 2E shows the dual-input transmission assembly 210 in operation to drive the output ring gear 152 and the rear-output internal ring gear 262 with the first motive power input (or the first rotary input) provided to the primary sun gear 128 according to various embodiments. As shown, the transfer-shaft-engagement-clutch-element 142 may engage the transfer shaft 132 and output-ring-gear-engagement-clutch-element 148 may be extended relative to the output- shaft-engagement-clutch-element 146 to engage the output ring gear 152. The transfer-ring-gear-engagement-clutch-element 144 may be retracted with respect to the transfer-shaft-engagement-clutch-element 142. Accordingly, with the first motive power input (or the first rotary input) provided to the primary sun gear 128, the transfer shaft 132 rotating together with the primary sun gear 128 may rotate the transfer- shaft-engagement-clutch-element 142 so as to rotate the output-ring-gear-engagement- clutch-element 148 for driving the output ring gear 152 to rotate. Further, the primary sun gear 128 may rotate and drive the set of planetary gears 124, and the set of planetary gears 124 with the third axial portions 224d of the set of planetary gear 124 in engagement with the rear-output internal ring gear 262 may drive the rear-output internal ring 262.

[000106] FIG. 2F shows the dual-input transmission assembly 210 in operation to drive the output ring gear 152 and the rear-output internal ring gear 262 with the second motive power input (or the second rotary input) provided to the primary internal ring gear 122 according to various embodiments. As shown, the transfer-ring-gear-engagement-clutch- element 144 may be extended away from the transfer-shaft-engagement-clutch-element 142 to engage the transfer internal ring gear 132 and the output-ring-gear-engagement-clutch- element 148 may be extended away from the output-shaft-engagement-clutch-element 146 to engage the output ring gear 152. Accordingly, with the second motive power input (or the second rotary input) provided to the primary internal ring gear 122, the primary internal ring gear 122 may drive the set of planetary gears 124 for rotating the transfer internal ring gear 132 in engagement with the second axial portions 124b of the set of planetary gears 124, the transfer internal ring gear 132 may rotate the transfer-ring-gear-engagement-clutch- element 144 so as to rotate the output-ring-gear-engagement-clutch-element 148 for driving the output ring gear 152. Further, the set of planetary gears 124 with the third axial portions 224d of the set of planetary gear 124 in engagement with the rear-output internal ring gear 262 may drive the rear-output internal ring 262.

[000107] FIG. 2G shows the dual-input transmission assembly 210 in operation to drive the output shaft 158 and the rear-output internal ring gear 262 with the second motive power input (or the second rotary input) provided to the primary internal ring gear 122 according to various embodiments. As shown, the transfer-ring-gear-engagement-clutch-element 144 may be extended away from the transfer-shaft-engagement-clutch-element 142 to engage the transfer internal ring gear 132 and output-shaft-engagement-clutch-element 146 may engage the output shaft 158. The output-ring-gear-engagement-clutch-element 148 may be retracted with respect to the output- shaft-engagement-clutch-element 146. Accordingly, with the second motive power input (or the second rotary input) provided to the primary internal ring gear 122, the primary internal ring gear 122 may drive the set of planetary gears 124 for rotating the transfer internal ring gear 132 in engagement with the second axial portions 124b of the set of planetary gears 124, the transfer internal ring gear 132 may rotate the transfer-ring-gear-engagement-clutch-element 144 so as to rotate the output- shaft- engagement-clutch-element 146 for driving the output shaft 158. Further, the set of planetary gears 124 with the third axial portions 224d of the set of planetary gear 124 in engagement with the rear-output internal ring gear 262 may drive the rear-output internal ring 262.

[000108] FIG. 2H shows the dual-input transmission assembly 210 in operation to drive the output shaft 158 and the rear-output internal ring gear 262 with the first motive power input (or the first rotary input) provided to the primary sun gear 128 and the second motive power input (or the second rotary input) provided to the primary internal ring gear 122 simultaneously according to various embodiments. The first motive power input (or the first rotary input) and the second motive power input (or the second rotary input) may be counter rotating. As shown, the transfer-ring-gear-engagement-clutch-element 144 may be extended away from the transfer- shaft-engagement-clutch-element 142 to engage the transfer internal ring gear 132 and output-shaft-engagement-clutch-element 146 may engage the output shaft 158. The output-ring-gear-engagement-clutch-element 148 may be retracted with respect to the output-shaft-engagement-clutch-element 146. Accordingly, with the counter-rotating first motive power input (or the first rotary input) and second motive power input (or the second rotary input) provided to the primary sun gear 128 and the primary internal ring gear 122 respectively, the counter-rotation of the primary sun gear 128 and the primary internal ring gear 122 may drive the set of planetary gears 124 for rotating the transfer internal ring gear 132 in engagement with the second axial portions 124b of the set of planetary gears 124, the transfer internal ring gear 132 may rotate the transfer-ring-gear-engagement-clutch- element 144 so as to rotate the output- shaft-engagement-clutch-element 146 for driving the output shaft 158. Further, the set of planetary gears 124 with the third axial portions 224d of the set of planetary gear 124 in engagement with the rear-output internal ring gear 262 may drive the rear-output internal ring 262.

[000109] FIG. 21 shows the dual-input transmission assembly 210 in operation to drive the output ring gear 152 and the rear-output internal ring gear 262 with the first motive power input (or the first rotary input) provided to the primary sun gear 128 and the second motive power input (or the second rotary input) provided to the primary internal ring gear 122 simultaneously according to various embodiments. The first motive power input (or the first rotary input) and the second motive power input (or the second rotary input) may be counter-rotating. As shown, the transfer-ring-gear-engagement-clutch-element 144 may be extended away from the transfer-shaft-engagement-clutch-element 142 to engage the transfer internal ring gear 132 and the output-ring-gear-engagement-clutch-element 148 may be extended away from the output-shaft-engagement-clutch-element 146 to engage the output ring gear 152. Accordingly, with the counter-rotating first motive power input (or the first rotary input) and second motive power input (or the second rotary input) provided to the primary sun gear 128 and the primary internal ring gear 122 respectively, the counter rotation of the primary sun gear 128 and the primary internal ring gear 122 may drive the set of planetary gears 124 for rotating the transfer internal ring gear 132 in engagement with the second axial portions 124b of the set of planetary gears 124, the transfer internal ring gear 132 may rotate the transfer-ring-gear-engagement-clutch-element 144 so as to rotate the output-ring-gear-engagement-clutch-element 148 for driving the output ring gear 152. Further, the set of planetary gears 124 with the third axial portions 224d of the set of planetary gear 124 in engagement with the rear-output internal ring gear 262 may drive the rear-output internal ring 262.

[000110] FIG. 2J shows a schematic drawing of a powertrain 200 for a vehicle, for example a vehicle capable of land and aerial transportation according to various embodiments. According to various embodiments, the powertrain 200 may include the dual input transmission assembly 210 of FIG. 2A to FIG. 2C. According to various embodiments, the powertrain 200 may, similar to the powertrain 100 of FIG. 1 J, include the first prime mover 102 (e.g. the engine) and the second prime mover 104 (e.g. the electric motor), which may be independent of each other. According to various embodiments, the first prime mover 102 (e.g. the engine) may be connected to the primary sun gear 128 of the dual input transmission assembly 210 for driving the primary sun gear 128 to rotate. According to various embodiments, the second prime mover 104 (e.g. the electric motor) may be connected to the input internal ring 122 gear of the dual input transmission assembly 210 for driving the primary internal ring gear 122 to rotate.

[000111] According to various embodiments, the powertrain 200 may, similar to the powertrain 100 of FIG. 1 J, include the controller 105 for controlling the planet carrier brake 125 and/or the second prime mover 104 (e.g. the electric motor).

[000112] According to various embodiments, the powertrain 200 may, similar to the powertrain 100 of FIG. 1 J, include the first propulsion unit 106 (e.g. a drive wheel) and the second propulsion unit 108 (e.g. an air propulsion unit). According to various embodiments, the first propulsion unit 106 (e.g. the drive wheel) may be connected to the output shaft 158 of the dual input transmission assembly 210. According to various embodiments, the second propulsion unit 108 (e.g. the air propulsion unit) may be connected to the output ring gear 152 of the dual input transmission assembly 210.

[000113] According to various embodiments, the powertrain 200 may differ from the powertrain 100 of FIG. 1J in that the powertrain 200 may further include an additional propulsion unit 109 connected to the rear-output internal ring 262 of the dual input transmission assembly 210. According to various embodiments, a clutch 109a may be connected between the rear-output internal ring 262 and the additional propulsion unit 109 such that the clutch 109a may selectively connect or disconnect the additional propulsion unit 109 to the rear-output internal ring 262.

[000114] FIG. 2K shows a schematic drawing of another powertrain 201 for a vehicle, for example a vehicle capable of land and aerial transportation according to various embodiments. According to various embodiments, the powertrain 201 of FIG. 2K differ from the powertrain 200 of FIG. 2J in that the the first propulsion unit 106 (e.g. the drive wheel) may be connected to the output ring gear 152 of the dual input transmission assembly 210 and the second propulsion unit 108 (e.g. the air propulsion unit) may be connected to the output shaft 158 of the dual input transmission assembly 210. [000115] FIG. 3A shows a schematic diagram of a dual-input transmission assembly 310 according to various embodiments. FIG. 3B shows a schematic exploded diagram of the dual-input transmission assembly 310 of FIG. 3A according to various embodiment. FIG. 3C shows a schematic cross-sectional diagram of the dual-input transmission assembly 310 of FIG. 3A according to various embodiments.

[000116] According to various embodiments, the dual-input transmission assembly 310 of FIG. 3 A to FIG. 3C may differ from the dual-input transmission assembly 210 of FIG. 2A to FIG. 2C in that the dual-input transmission assembly 310 of FIG. 3A to FIG. 3C may not include (be without) the output ring gear 152. Accordingly, the output ring gear 152 may be absence from the dual-input transmission assembly 310 of FIG. 3 A to FIG. 3C. Accordingly, the output zone 150 of the dual-input transmission assembly 310 of FIG. 3A to FIG. 3C may only include the output shaft 158. Hence, the clutch mechanism 140 may be between the output shaft 158 and the pinions-and- internal-gear-set- zone 130. Thus, the clutch mechanism 140 may couple only the output shaft 158 to the pinions-and-intemal- gear-set-zone 130.

[000117] According to various embodiments, the dual-input transmission assembly 310 of FIG. 3 A to FIG. 3C may further differ from the dual-input transmission assembly 210 of FIG. 2A to FIG. 2C in that the clutch mechanism 140 of the dual-input transmission assembly 310 of FIG. 3A to FIG. 3C may not include (be without) the output-ring-gear- engagement-clutch-element 148 in the second set of clutch elements. Accordingly, the second set of clutch elements of the clutch mechanism 140 of the dual-input transmission assembly 310 of FIG. 3A to FIG. 3C may only include the output- shaft-engagement-clutch- element 146. Hence, the clutch mechanism 140 of the dual-input transmission assembly 310 of FIG. 3A to FIG. 3C may be operable to selectively engage or disengage the output shaft 158 with the output-shaft-engagement-clutch-element 146 for selectively connecting or disconnecting the output shaft 158 to the transfer internal ring gear 132 or the transfer shaft 138.

[000118] According to various embodiments, in the dual-input transmission assembly 310 of FIG. 3A to FIG. 3C, the clutch mechanism 140 between the pinions-and-internal-gear- set-zone 130 and the output shaft 158 may be configured to couple the transfer internal ring gear 132 or the transfer shaft 138 to the output shaft 158 for transmitting the rotation of the transfer internal ring gear 132 or the transfer shaft 138 to the output shaft 158. According to various embodiments, the clutch mechanism 140 may from a clutch coupling to connect both the transfer shaft 138 and the transfer internal ring gear 132 to the output shaft 158 and operable to selectively connect or disconnect the transfer shaft 138 or the transfer internal ring gear 132 to the output shaft 158. For example, when the clutch mechanism 140 connects the transfer shaft 138 to the output shaft 158, the first motive power input (or the first rotary input) from the first prime mover (e.g. the engine) may be directly transmitted to the output shaft 158 via the primary sun gear 128 and the transfer shaft 138 and through the clutch mechanism 140 to the output shaft 158. For example, when the clutch mechanism 140 connects the transfer internal ring gear 132 to the output shaft 158, the second motive power input (or the second rotary input) from the second prime mover (e.g. the electric motor) may be transmitted to the output shaft 158 via the primary internal ring gear 122 to the set of planetary gears 124, from the set of planetary gears 124 to the transfer internal ring gear 132, and from the transfer internal ring gear 132 to the output shaft 158 through the clutch mechanism 140. As another example, when the clutch mechanism 140 connects the transfer internal ring gear 132 to the output shaft 158, counter-rotating the primary sun gear 128 and the primary internal ring gear 122 by the combined first and second motive power inputs (or the combined first second rotary inputs) from the first and second prime movers (e.g. the engine and the electric motor) may transmit a resultant rotation to the output shaft 158 via the counter-rotation between the primary internal ring gear 122 and the primary sun gear 128 to the set of planetary gears 124, from the set of planetary gears 124 to the transfer internal ring gear 132, and from the transfer internal ring gear 132 to the output shaft 158 through the clutch mechanism 140.

[000119] According to various embodiments, in the dual-input transmission assembly 310 of FIG. 3 A to FIG. 3C, the clutch mechanism 140 may include the first set of clutch elements 142, 144 and the second set of clutch elements 146. According to various embodiments, the first set of clutch elements 142, 144 may be for connecting to one or both of the transfer internal ring gear 132 and the transfer shaft 138. According to various embodiments, the second set of clutch elements 146 may be for connecting to the output shaft 158. According to various embodiments, the first set of clutch elements 142, 144 and the second set of clutch elements 146 may be interconnected in a manner so as to be rotatable together in a synchronized manner (i.e. at the same time and same speed) about the central rotational axis 112. Accordingly, the first set of clutch elements 142, 144 and the second set of clutch elements 146 may be interlocked to each other in the circumferential direction so as to be non-movable relative to each other in the circumferential direction. Hence, a rotation about the central rotational axis 112 impart to the first set of clutch elements 142, 144 may result in the second set of clutch elements 146 rotating together in a synchronized manner (i.e. at the same time and same speed).

[000120] According to various embodiments, the first set of clutch elements 142, 144 of the dual-input transmission assembly 310 of FIG. 3A to FIG. 3C may be identical with the first set of clutch elements 142, 144 of the dual-input transmission assembly 110 of FIG. 1A to FIG. 1C and the first set of clutch elements 142, 144 of the dual-input transmission assembly 210 of FIG. 2A to FIG. 2C which may include the transfer-shaft-engagement- clutch-element 142 and the transfer-ring-gear-engagement-clutch-element 144.

[000121] According to various embodiments, in the dual-input transmission assembly 310 of FIG. 3A to FIG. 3C, the second set of clutch elements 146 may include only the output- shaft-engagement-clutch-element 146. According to various embodiments, the output-shaft- engagement-clutch-element 146 may be movable along the central rotational axis 112 towards and away from the output shaft 158 for engaging and disengaging with the output shaft 158. Accordingly, output-shaft-engagement-clutch-element 146 may move towards and engage the output shaft 158 such that a rotation of the output-shaft-engagement-clutch- element 146 may be transmitted to the output shaft 158. Further, the output- shaft- engagement-clutch-element 146 may move away and disengage from the output shaft 158 such that the rotation of the output-shaft-engagement-clutch-element 146 may no longer be transmitted to the output shaft 158. According to various embodiments, the output-shaft- engagement-clutch-element 146 may engage the output shaft 158 via friction engagement. [000122] According to various embodiments, the transfer-shaft-engagement-clutch- element 142 and the output-shaft-engagement-clutch-element 146 may be interconnected in a manner so as to be rotatable together in a synchronized manner (i.e. at the same time and same speed) about the central rotational axis 112. Accordingly, the transfer- shaft- engagement-clutch-element 142 and the output-shaft-engagement-clutch-element 146 may be interlocked to each other in the circumferential direction so as to be non-movable relative to each other in the circumferential direction. Hence, rotating the transfer-shaft-engagement- clutch-element 142 may result in the output-shaft-engagement-clutch-element 146 rotating together in a synchronized manner (i.e. at the same time and same speed).

[000123] According to various embodiments, the transfer-shaft-engagement-clutch- element 142 and the output- shaft-engagement-clutch-element 146 may be movable relative to each other in a telescopic manner. According to various embodiments, the transfer- shaft- engagement-clutch-element 142 may be movable away from the output-shaft-engagement- clutch-element 146 telescopically so as to extend away from the output-shaft-engagement- clutch-element 146 to engage with the transfer shaft 138 and to retract the transfer- shaft- engagement-clutch-element 142 back towards the output-shaft-engagement-clutch-element 144 to disengage from the transfer shaft 138. According to various embodiments, the output- shaft-engagement-clutch-element 146 may be movable away from the transfer-shaft- engagement-clutch-element 142 telescopically so as to extend the output-shaft-engagement- clutch-element 146 away from the transfer- shaft-engagement-clutch-element 142 to engage with the output shaft 158 and to retract the output-shaft-engagement-clutch-element 146 back towards the transfer-shaft-engagement-clutch-element 142 to disengage from the output shaft 158. According to various embodiments, the transfer-shaft-engagement-clutch- element 142 and the output- shaft-engagement-clutch-element 146 may be movable away from each other telescopically to extend away from each other such that the transfer-shaft- engagement-clutch-element 142 may engage the transfer shaft 132 and the output-shaft- engagement-clutch-element 146 may engage the output shaft 158, and to retract towards each other such that the transfer- shaft-engagement-clutch-element 142 may disengage from the transfer shaft 138 and the output-shaft-engagement-clutch-element 146 may disengage from the output shaft 158.

[000124] FIG. 3D shows the dual-input transmission assembly 310 in operation to drive the output shaft 158 and the rear-output internal ring gear 262 with the first motive power input (or the first rotary input) provided to the primary sun gear 128 according to various embodiments. As shown, the transfer-shaft-engagement-clutch-element 142 and the output- shaft-engagement-clutch-element 146 may be extended away from each other telescopically such that the transfer-shaft-engagement-clutch-element 142 may engage the transfer shaft 132 and the output-shaft-engagement-clutch-element 146 may engage the output shaft 158. The transfer-ring-gear-engagement-clutch-element 144 may be retracted with respect to the transfer- shaft-engagement-clutch-element 142. Accordingly, with the first motive power input (or the first rotary input) provided to the primary sun gear 128, the transfer shaft 132 rotating together with the primary sun gear 128 may rotate the transfer- shaft-engagement- clutch-element 142 so as to rotate the output-shaft-engagement-clutch-element 146 for driving the output shaft 158 to rotate. Further, the primary sun gear 128 may rotate and drive the set of planetary gears 124, and the set of planetary gears 124 with the third axial portions 224d of the set of planetary gear 124 in engagement with the rear-output internal ring gear 262 may drive the rear-output internal ring 262.

[000125] FIG. 3E shows the dual-input transmission assembly 310 in operation to drive the rear-output internal ring gear 262 with the first motive power input (or the first rotary input) provided to the primary sun gear 128 according to various embodiments. As shown, the output- shaft-engagement-clutch-element 146 may be disengaged from the output shaft 158. The transfer-ring-gear-engagement-clutch-element 144 may also be retracted with respect to the transfer- shaft-engagement-clutch-element 142 so as to be disengaged from the transfer internal ring gear 132. Accordingly, the output shaft 158 may not be rotated. The clutch mechanism 140 may also not be rotated. Further, the primary sun gear 128 may rotate and drive the set of planetary gears 124, and the set of planetary gears 124 with the third axial portions 224d of the set of planetary gear 124 in engagement with the rear-output internal ring gear 262 may drive the rear-output internal ring 262.

[000126] FIG. 3F shows the dual-input transmission assembly 310 in operation to drive the rear-output internal ring gear 262 with the second motive power input (or the second rotary input) provided to the primary internal ring gear 122 according to various embodiments. As shown, the output-shaft-engagement-clutch-element 146 may be disengaged from the output shaft 158. The transfer-ring-gear-engagement-clutch-element 144 may also be retracted with respect to the transfer-shaft-engagement-clutch-element 142 so as to be disengaged from the transfer internal ring gear 132. Accordingly, the output shaft 158 may not be rotated. The clutch mechanism 140 may also not be rotated. Hence, with the second motive power input (or the second rotary input) provided to the primary internal ring gear 122, the primary internal ring gear 122 may drive the set of planetary gears 124 for rotating the rear-output internal ring gear 262 in engagement with the third axial portions 224d of the set of planetary gears 124.

[000127] FIG. 3G shows the dual-input transmission assembly 310 in operation to drive the output shaft 158 and the rear-output internal ring gear 262 with the second motive power input (or the second rotary input) provided to the primary internal ring gear 122 according to various embodiments. As shown, the transfer-ring-gear-engagement-clutch-element 144 may be extended away from the transfer-shaft-engagement-clutch-element 142 to engage the transfer internal ring gear 132 and output-shaft-engagement-clutch-element 146 may engage the output shaft 158. Accordingly, with the second motive power input (or the second rotary input) provided to the primary internal ring gear 122, the primary internal ring gear 122 may drive the set of planetary gears 124 for rotating the transfer internal ring gear 132 in engagement with the second axial portions 124b of the set of planetary gears 124, the transfer internal ring gear 132 may rotate the transfer-ring-gear-engagement-clutch-element 144 so as to rotate the output- shaft-engagement-clutch-element 146 for driving the output shaft 158. Further, the set of planetary gears 124 with the third axial portions 224d of the set of planetary gear 124 in engagement with the rear-output internal ring gear 262 may drive the rear-output internal ring 262.

[000128] FIG. 3H shows the dual-input transmission assembly 310 in operation to drive the output shaft 158 and the rear-output internal ring gear 262 with the first motive power input (or the first rotary input) provided to the primary sun gear 128 and the second motive power input (or the second rotary input) provided to the primary internal ring gear 122 simultaneously according to various embodiments. The first motive power input (or the first rotary input) and the second motive power input (or the second rotary input) may be counter rotating. As shown, the transfer-ring-gear-engagement-clutch-element 144 may be extended away from the transfer- shaft-engagement-clutch-element 142 to engage the transfer internal ring gear 132 and output-shaft-engagement-clutch-element 146 may engage the output shaft 158. Accordingly, with the counter-rotating first motive power input (or the first rotary input) and second motive power input (or the second rotary input) provided to the primary sun gear 128 and the primary internal ring gear 122 respectively, the counter-rotation of the primary sun gear 128 and the primary internal ring gear 122 may drive the set of planetary gears 124 for rotating the transfer internal ring gear 132 in engagement with the second axial portions 124b of the set of planetary gears 124, the transfer internal ring gear 132 may rotate the transfer-ring-gear-engagement-clutch-element 144 so as to rotate the output- shaft- engagement-clutch-element 146 for driving the output shaft 158. Further, the set of planetary gears 124 with the third axial portions 224d of the set of planetary gear 124 in engagement with the rear-output internal ring gear 262 may drive the rear-output internal ring 262.

[000129] FIG. 31 shows the dual-input transmission assembly 310 in operation to drive the rear-output internal ring gear 262 with the first motive power input (or the first rotary input) provided to the primary sun gear 128 and the second motive power input (or the second rotary input) provided to the primary internal ring gear 122 simultaneously according to various embodiments. The first motive power input (or the first rotary input) and the second motive power input (or the second rotary input) may be counter-rotating. As shown, the output- shaft-engagement-clutch-element 146 may be disengaged from the output shaft 158. The transfer-ring-gear-engagement-clutch-element 144 may also be retracted with respect to the transfer- shaft-engagement-clutch-element 142 so as to be disengaged from the transfer internal ring gear 132. Accordingly, the output shaft 158 may not be rotated. The clutch mechanism 140 may also not be rotated. Accordingly, with the counter-rotating first motive power input (or the first rotary input) and second motive power input (or the second rotary input) provided to the primary sun gear 128 and the primary internal ring gear 122 respectively, the counter-rotation of the primary sun gear 128 and the primary internal ring gear 122 may drive the set of planetary gears 124 for rotating the rear-output internal ring gear 262 in engagement with the third axial portions 224d of the set of planetary gears 124.

[000130] FIG. 3J shows a schematic drawing of a powertrain 300 for a vehicle, for example a vehicle capable of land and aerial transportation according to various embodiments. According to various embodiments, the powertrain 300 may include the dual input transmission assembly 310 of FIG. 3 A to FIG. 3C. According to various embodiments, the powertrain 300 may, similar to the powertrain 100 of FIG. 1 J and the powertrain 200 of FIG. 2J, include the first prime mover 102 (e.g. the engine) and the second prime mover 104 (e.g. the electric motor), which may be independent of each other. According to various embodiments, the first prime mover 102 (e.g. the engine) may be connected to the primary sun gear 128 (for example via the input shaft 118) of the dual input transmission assembly 310 for driving the primary sun gear 128 to rotate. According to various embodiments, the second prime mover 104 (e.g. the electric motor) may be connected to the input internal ring 122 gear of the dual input transmission assembly 310 for driving the primary internal ring gear 122 to rotate.

[000131] According to various embodiments, the powertrain 300 may, similar to the powertrain 100 of FIG. 1J and the powertrain 200 of FIG. 2J, include the controller 105 for controlling the planet carrier brake 125 and/or the second prime mover 104 (e.g. the electric motor).

[000132] According to various embodiments, the powertrain 300 may, similar to the powertrain 100 of FIG. 1J and the powertrain 200 of FIG. 2J, include the first propulsion unit 106 (e.g. a drive wheel) and the second propulsion unit 108 (e.g. an air propulsion unit). According to various embodiments, the first propulsion unit 106 (e.g. the drive wheel) may be connected to the output shaft 158 of the dual input transmission assembly 310. However, according to various embodiments, the second propulsion unit 108 (e.g. the air propulsion unit) may be connected to the rear-output internal ring gear 262 of the dual input transmission assembly 310. According to various embodiments, a clutch 108a may be connected between the rear-output internal ring 262 and the second propulsion unit 108 (e.g. the air propulsion unit) such that the clutch 108a may selectively connect or disconnect the second propulsion unit 108 (e.g. the air propulsion unit) to the rear-output internal ring 262. [000133] FIG. 3K shows a schematic drawing of another powertrain 301 for a vehicle, for example a vehicle capable of land and aerial transportation according to various embodiments. According to various embodiments, the powertrain 301 of FIG. 3K differ from the powertrain 300 of FIG. 3J in that the the first propulsion unit 106 (e.g. the drive wheel) may be connected to the rear-output internal ring gear 262 of the dual input transmission assembly 310 and the second propulsion unit 108 (e.g. the air propulsion unit) may be connected to the output shaft 158 of the dual input transmission assembly 310. According to various embodiments, a clutch 106a may be connected between the rear-output internal ring 262 and the first propulsion unit 106 (e.g. the drive wheel) such that the clutch 106a may selectively connect or disconnect the first propulsion unit 106 (e.g. the drive wheel) to the rear-output internal ring 262.

[000134] Various embodiments have provided a versatile dual input transmission assembly for use in a powertrain of a vehicle, such as a vehicle capable of land and aerial transportation (i.e. flying car). According to various embodiments, the dual-input transmission assembly may selectively transmit and/or adapt either a first motive power input (or a first rotary input) from a first prime mover, or a second motive power input (or a second rotary input) from a second prime mover, or a combined motive power input (or a combined rotary input) from both the first prime mover and the second prime mover together as a transmission-output for driving a propulsion unit (for example a drive wheel or an air propulsion unit). According to various embodiments, the dual-input transmission assembly may be coupled to two separate independent propulsion units (for example one drive wheel and one air propulsion unit) such that the dual-input transmission assembly may selectively drive either the first propulsion unit (e.g. the drive wheel) or the second propulsion unit (e.g. the air propulsion unit) or both using either the first motive power input from the first prime mover, or the second motive power input from the second prime mover, or the combined motive power input from both the first prime mover and the second prime mover together. [000135] Various embodiments have also provided a corresponding powertrain using the dual input transmission assembly. According to various embodiments, the powertrain may be readily switchable, via the dual-input transmission assembly, between the two separate independent prime movers (for example an engine and an electric motor) as redundancy to serve as backup or fail-safe for each other. According to various embodiments, the powertrain may also be readily switchable, via the dual-input transmission assembly, between the two separate independent propulsion units. For example, between the drive wheel and the air propulsion unit in the vehicle capable of land and aerial transportation (i.e. flying car) for providing ground propulsion or air propulsion respectively to the vehicle. According to various embodiments, the powertrain may allow for a true dual redundancy safety system, whereby if one of the prime movers of the vehicle (e.g. the electric motor) fails, the vehicle may still be maneuvered and powered using the other prime mover (e.g. the engine), or vice versa, regardless of the propulsion unit (the drive wheel or the air propulsion unit) that is being driven. According to various embodiments, the powertrain may also enable travel via multi-modes.

[000136] Various embodiments have provided an effective powertrain solution without compromising performance and/or safety. For example, various embodiments may enable better safety and meet aerospace safety requirements by having redundancy (i.e. the ability to have two powerplants or prime mover concurrently running in one system). Various embodiments may also meet aerospace safety requirements by providing a failsafe configuration which existing electrical powerplants (or prime movers) are unable to demonstrate similar failsafe characteristics. Existing electrical powerplants (or prime movers) typically fail immediately leading to catastrophic consequences. As non-limiting examples, various embodiments may also be applied in conventional aircraft where two electrical powerplants may be used in replacement of a single jet turbine engine, or a mix of two of the fan and/or compressors. Various embodiments may also be applied in electrical power generating systems where a single generator may be operated with two prime movers, or having a single prime mover operating two generators.

[000137] While the invention has been particularly shown and described with reference to specific embodiments, it should be understood by those skilled in the art that various changes, modification, variation in form and detail may be made therein without departing from the scope of the invention as defined by the appended claims. The scope of the invention is thus indicated by the appended claims and all changes which come within.