TECHNICAL FIELD

[0001] The present disclosure relates to the field of drive trains for vehicles. More particularly, the present disclosure relates to a universal drive train system with multiple input and multiple output configurations that allows integration of the transmission of the vehicle with various types of power sources, and which can be implemented in any of a fuel-only vehicle, a hybrid vehicle, and/or an electric vehicle, as well as in high power applications, and can also be used to retrofit existing fuel-based vehicles with battery and electric motors to convert the fuel-based vehicles into hybrid vehicles.

BACKGROUND

[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[0003] Drive trains (also referred to as drive train) are implemented in vehicles for delivering power to the driving wheels of the vehicles. The function of the drive train is to couple a power source such as an engine and electric motor that generates mechanical power, to the driving wheels or to the axle that uses this mechanical power to rotate the wheels. Generally, the drive trains are in a linear architecture such that the fuel engine, transmission and differential are connected in linear manner, where the output of the fuel engine or power source is connected to a transmission, the output of the transmission is connected further to the input of the differential. The drive train is generally implemented by incorporating any of the existing transmissions such as manual transmission, automated manual transmission, planetary gears automatic transmission, dual-clutch transmission, continuously variable (belt- driven) transmission, depending on the type of vehicle and application.

[0004] In fuel-only vehicle, the input of the drive train is connected to the engine of the vehicle, which acts as the power source, and the output of the drive train is connected to the driving wheels through the gear arrangement, differential, and/or clutch mechanism. Further, in an electric vehicle (EV), the input of the drive train is connected to an electric motor/generator, which acts as the power source, and the output of the drive train is connected to the driving wheels through a set of gears. Furthermore, fuel-electric (hybrid) vehicles include an engine and an electric motor/generator as two power sources. A hybrid vehicle uses similar technology as the fuel-only vehicles, in which the drive train takes a single input from the engine and provides output to the wheels. The motor is placed between the engine, and the drive train is adapted to add torque of the motor to that of the engine. The combined torque is then transmitted to the wheels from the transmission through a differential.

[0005] In such kind of architecture, the electric motor is either placed at the input side of the transmission or the output side of the transmission. When the electric motor is placed at the input side of the transmission, the RPMs of the electric motor always remain same as that of the fuel engine. Such drive trains do not provide a mechanism where the RPMs of the electric motor to be different than that of the fuel engine. In another scenario, when the electric motor is placed at the output end of the transmission, then the RPM of the electric motor are in fixed ratio to the RPM of the wheels. And this ratio remains fixed for the vehicle. In both these scenarios, it leads to limitation that the electric motor’s RPMs are either matched with fuel engine or with wheels. Hence if a new and flexible drive train is developed where the RPMs of the electric motor are varied in comparison with both, the fuel engine as well as electric motor, then the above mentioned limitations will no longer exist.

[0006] There is therefore a need in the art to provide a new configuration of drive train that overcomes above stated limitation of the conventional drive trains for vehicles.

OBJECTS OF THE PRESENT DISCLOSURE

[0007] An object of the present disclosure is to address the above-mentioned limitations inherent in the conventional drive trains for vehicles.

[0008] Another object of the present disclosure is to overcome the limitations of the conventional drive trains by simple and minor changes to the drive train without adding complexities into existing transmissions.

[0009] Another object of the present disclosure isto provide a universal drive train system with multiple inputs and multiple outputs configurations.

[0010] Another object of the present disclosure is to provide a universal drive train system that can be implemented in any of a fuel only vehicle, a hybrid vehicle, and an electric vehicle.

[0011] Another object of the present disclosure is to provide a universal drive train system which allows integration of the transmission of the vehicles with various types of power sources. [0012] Another object of the present disclosure is to provide a universal drive train system that can be used to retrofit existing fuel-based vehicles with battery and electric motors to convert the fuel-based vehicles into hybrid vehicles.

SUMMARY

[0013] Aspects of the present disclosure relate to a drive train for vehicles. In particular, the present disclosure provides a drive train having parallel architecture where the power source, such as an electric motor, is placed in parallel to the transmission such that the RPM of the electric motor is held at an average value of the RPMs of the input shaft and output shaft of the transmission with the help of a differential, thereby overcoming limitation of conventional drive trains having a linear architecture in a one-in-one-out configuration.

[0014] In an aspect, the present disclosure provides a drive train having a power source coupled to a transmission assembly (also referred to simply as transmission, and the two terms used interchangeably herein) in parallel through a differential. The disclosed drive train includes a transmission assembly having an input shaft and an output shaft, and a differential. The transmission assembly is configured to provide different speed reduction ratios between the input shaft and the output shaft. The differential is configured to receive power from a power source, and comprises two differential outputs comprising a first differential output and a second differential output. One of the two differential outputs is coupled to the input shaft of the transmission assembly and the other of the two differential outputs is coupled to the output shaft of the transmission assembly.

[0015] In an embodiment, the output shaft of the transmission assembly may be configured to supply power to a set of wheels through an axle differential.

[0016] In an embodiment, the transmission assembly may be configured such that the input shaft and the output shaft have same direction of rotation. Each of the two differential outputs may be coupled to the input shaft and the output shaft respectively by a pair of gears. In an alternate application, the transmission assembly may be configured such that the input shaft and the output shaft rotate in opposite directions, in which case one of the input shaft and the output shaft may be coupled to the corresponding differential output by a pair of gears and other of the input shaft and the output shaft may be coupled to the other differential output shaft by a pair of gears with an idler gear there between.

[0017] In an embodiment, the input shaft of the transmission assembly may be configured for coupling to a second power source. In an implementation, the first power source may be an IC engine and the second power source may be a motor. [0018] In one or more embodiments. The output shaft of the transmission assembly may be configured for coupling to a third power source.

[0019] In an embodiment, the drive train may include a planetary gear set and the third power source may be coupled to a ring gear of the planetary gear set, the output shaft may be coupled to a sun gear of the planetary gear set and the axle differential may be coupled to a planetary carrier of the planetary gear set.

[0020] In an embodiment, the first and third power sources may be motors and the second power source may be an IC engine.

[0021] In one or more embodiments, the drive train may include at least one clutch configured in series with the IC engine.

[0022] An aspect of the present disclosure relates to a drive train where a power source is coupled to a transmission assembly in parallel through a planetary gear set. The disclosed drive train includes a transmission assembly having an input shaft and an output shaft, and configured to provide different speed reduction ratios between the input shaft and the output shaft. The drive train further includes a planetary gear set coupled to the transmission assembly and the power source such that a planetary carrier of the planetary gear set is operatively connected to the power source; and a ring gear of the planetary gear set is coupled to the output shaft of the transmission assembly and a sun gear of the planetary gear set is coupled to the input shaft of the transmission assembly or vice a versa.

[0023] In an embodiment, the output shaft of the transmission assembly may be configured to supply power to a set of wheels through an axle differential.

[0024] In an embodiment, the transmission assembly may be configured such that the input shaft and the output shaft rotate in opposite directions, and the ring gear of the planet carrier is coupled to output shaft of the transmission assembly and sun gear maybe coupled via an idler gear to the input shaft of the transmission assembly or vice a versa.

[0025] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF DRAWINGS

[0026] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. The diagrams are for illustration only, which thus is not a limitation of the present disclosure.

[0027] In the figures, similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label with a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.

[0028] FIG. 1 illustrates an exemplary schematic arrangement of the disclosed drive train with a first power source coupled to a transmission assembly through a differential, where two outputs of the differential are coupled to input and output shafts of the transmission through a pair of gears, in accordance with embodiments of the present invention.

[0029] FIG. 2 illustrates an exemplary schematic arrangement of the drive train with an IC engine as a first power source coupled to a transmission assembly through a differential, where one of the input and output shafts is coupled to the corresponding output of the differential through a pair of gears, and other of the input and output shafts is coupled to the corresponding output of the differential through a pair of gears and an idler there between, in accordance with embodiments of the present invention.

[0030] FIG. 3 illustrates an exemplary schematic arrangement of the disclosed drive train with an IC engine as a first power source coupled to a transmission assembly through a planetary gear set, in accordance with embodiments of the present invention.

[0031] FIG. 4 illustrates an exemplary schematic arrangement of the drive train of FIG. 1 with a motor as a second power source coupled to a transmission assembly through a planetary gear set, in accordance with embodiments of the present invention.

[0032] FIG. 5 illustrates an exemplary schematic arrangement of the drive train of FIG. 1 with a motor as a third power source coupled to the output shaft of the transmission, in accordance with embodiments of the present invention.

[0033] FIG. 6 illustrates an exemplary schematic arrangement of the drive train of FIG. 1 with a motor as a first power source, an IC engine as a second power source coupled to the input shaft and a motor as a third power source coupled to the output shaft of the transmission, in accordance with embodiments of the present invention. [0034] FIG. 7 illustrates an exemplary schematic arrangement of the drive train of FIG. 6 with the second power source coupled to the input shaft through a planetary gear set, in accordance with embodiments of the present invention.

[0035] FIG. 8 illustrates an exemplary schematic arrangement of the drive train of FIG. 6 with a clutch provided between the transmission and the third power source to enable running the drive as a pure electric drive, in accordance with embodiments of the present invention.

[0036] FIG. 9 illustrates an exemplary schematic arrangement of the drive train of FIG. 6 with the third power source coupled to the output shaft through a planetary gear set, in accordance with embodiments of the present invention.

DETAILED DESCRIPTION

[0037] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.

[0038] In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. It will be apparent to one skilled in the art that embodiments of the present invention may be practiced without some of these specific details.

[0039] If the specification states a component or feature “may”, “can”, “could”, or “might” be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.

[0040] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.

[0041] The use of “including”, “comprising” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. Further, the use of terms “first”, “second”, and “third”, and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another.

[0042] The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.

[0043] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.

[0044] Embodiments of the present disclosure relate to a universal drive train system with multiple input and multiple output configurations that allows integration of the transmission of the vehicles with various types of power sources, and which can be implemented in any fuel-only vehicle, hybrid vehicle, and/or electric vehicle, as well as in high power applications, and can also be used to retrofit existing fuel-based vehicles with battery and electric motors to convert the fuel-based vehicles into hybrid vehicles.

[0045] In an aspect, the disclosed drive train includes a unique enhancement in the way a power source is connected with a transmission of the drive train. Instead of building a drive train by connecting the power source, transmissions and differential in a linear manner, the present disclosure provides a novel way of connecting the power source in parallel to the transmission, where the output from the power source is connected to the input and output of the transmission simultaneously via either a differential or a planetary gear set.

[0046] Hence, a new parallel drive train architecture is proposed where the power source, such as an electric motor, is placed in parallel to the transmission, such that the RPM of the electric motor is held at an average value of the RPMs of the input shaft and output shaft of the transmission with the help of a differential.

[0047] As the conventional drive trains of the vehicles are in a linear architecture in a one-in-one-out configuration, they are limited to transferring mechanical power of one power source as input to the wheels (as single output), and fail to provide a universal multi-in and multi-out configuration, which can be integrated with various types of different power sources. As a result, a single existing drive train cannot be implemented in different vehicles including fuel-only vehicles, hybrid vehicles, or even electric vehicles for extending the range of EVs. The drive train of the present disclosure overcomes this limitation of the conventional drive trains.

[0048] The FIG.l shows a drive train with transmission 10, a geared wheel 11 connected to the input of the transmission, geared wheel 12 connected to the output of the transmission, an output shaft 19 connecting the transmission to the differential 13, a geared wheel 21 meshed with the geared wheel 11, the geared wheel 22 meshed with geared wheel 12, both geared wheels 21 and 22 are connected to the left side shaft and right side shaft of the differential 20, the center wheel of the differential is meshed with the geared wheel 31 which is driven by the power source 30 (also referred to as first power source, herein), which can be any power source such as an IC engine or electric motor with a clutch mechanism 32 incorporated between the power source 30 and geared wheel 31. Thus, the power source 30 and differential 20 are together arranged in parallel with the transmission 10.

[0049] The transmission denoted by 10 can be any standard transmission i.e. manual transmission or automatic transmission or dual clutch transmission or belt driven transmission or any other transmission which can be available. The only fundamental requirement would be that the output shaft of the transmission and the input shaft of the transmission will have same rotational direction. The geared wheel 11 is fixed on the input shaft of the transmission 10 and rotates at the same speed as the input shaft. This geared wheel 11 is placed to receive the power from the power source towards the input of the transmission. The geared wheel 12 is fixed on the output shaft 19 of the transmission 10. This geared wheel 12 rotates at the same speeds as the output shaft 19 and receives the power from the power source towards the output of the transmission. The output shaft 19 further drives the differential 13 (also referred to as axle differential 13, herein), which then drives the wheels through the axle (wheels and axle not shown in the figure).

[0050] If the rotational directions of the input shaft and the output shaft are opposite to each other, then an idle gear is required to be introduced on either the input side or output side of the transmission. The FIG. 2 shows one such embodiment where an idle gear is introduced on the output side of the transmission. The geared wheel 12 and geared wheel 22 are not directly meshed into each other in this case. Instead, an idle gear 1222 is introduced in between the geared wheels 12 and 22. This way same rotational direction of the left-side geared wheel 21 and right-side geared wheel 22 is maintained for the differential 20 even if the input shaft and output shaft of the transmission 10 have opposite rotational directions. [0051] FIG. 3 shows another such embodiment where the direction of rotation of input shaft and output shaft of the transmission 10 is opposite to each other. As a result, the direction of rotation of the input side geared wheel 11 and output side geared wheel 12 are opposite to each other. This embodiment shows a planetary gear arrangement 20 instead of the differential arrangement. This illustration shows one idle gear on the input side of the transmission. The idle gear 1121 is placed in between the geared wheels 11 and 21. The planetary gear 20 is incorporated with its ring gear denoted as 20r, the planet carrier is denoted as 20p and sun gear is denoted as 20s. The geared wheel 21 is connected to the sun gear 20s. The geared wheel 12 on the output side of the transmission directly meshed with the ring gear 20r while the planet carrier 20p is driven by the fuel engine 30.

[0052] In case of both the embodiments depicted in FIG.1 and 2, the power source 30 such as fuel engine transmits the power to the differential 20 via a clutch 32 and geared wheel 31. This way the center wheel of the differential receives the power which then drives the left and right geared wheels 21 and 22. These wheels may be driven at same speed or at different speeds based on the gear engaged on the transmission. If the lower gear is engaged on the transmission 10 then the left side geared wheel 21 and input side geared wheel 11 will be driven at higher speeds than the right-side geared wheel 22 and output side geared wheel 12. When the gear of the transmission is changed to the higher gear where the input and output shafts of the transmission rotate at the same speed, the geared wheels 21 and 22 will also rotate at the same speed. When the gear of the transmission is further increased, the rotational speed of the output shaft is higher than the rotational speed of the input shaft. In such a case the geared wheel 22 rotates faster than the geared wheel 21. Thus, the power is transmitted from the power source 30 simultaneously towards the input and output of the transmission 10 via the differential 20. One of the advantages of this arrangement is eliminate the rubber band effect typically seen in the CVT transmissions.

[0053] FIG. 4 shows one embodiment where two power sources are incorporated in the drive train. The interconnections between transmission 10, the differential 20 and the fuel engine 30 remain the same as described in the FIG. 1. There is second power source, e.g. an electric motor, is added to drive the geared wheel 11. Thus, the geared wheel 11 receives the power from the power source 30 as well as the power source 40. As an illustration purpose, a geared wheel 41 is shown meshed with the geared wheel 11. The wheel 41 connects to the rotor of the electric motor thereby drawing power from the electric motor and transferring to the input of the transmission 10. [0054] The drive train arrangement described in FIG. 5 is very similar to that of the FIG. 4 with slight modification for the interconnection of the electric motor. In this embodiment, the electric motor is placed on the output side of the transmission as a third power source. The rotor of the electric motor is connected to the geared wheel 42 which is meshed with the geared wheel 12 that drives the output shaft 19 of the transmission 10. This way the power from the two power sources, i.e. fuel engine 30 and electric motor 40 are coupled on the output side of the transmission.

[0055] The FIG. 6 shows a different variation of the drive train. The arrangement between the transmission 10 and differential 20 is exactly same as that shown in the FIG. 1. But in this embodiment, the differential 20 is driven by an electric motor instead of a fuel engine. The electric motor in this figure is denoted as 33 which drives the differential 20. The fuel engine 15 is connected to the clutch 16 which then connects to the input shaft of the transmission 10. The arrangement of the second electric motor 40 in this embodiment is same as shown in the FIG. 4.

[0056] FIG. 7 shows another embodiment of the drive train where a planetary gear set 17 is introduced between the second power source and the transmission. The planetary gear set is introduced on the input side of the transmission. The fuel engine is connected to the ring gear 17r. The planet carrier 17p is connected to the input of the transmission. The input side gear 11 is connected to the sun gear 17s. The arrangements of the differential 20, input power sources, i.e. electric motors 33 and 40 are the same as in the FIG. 1. The clutch brake arrangement is also provided to brake the ring gear when the fuel engine is not driving the vehicle. In this case, the vehicle will be driven in the EV mode by the electric motors 33 and 40.

[0057] FIG. 8 shows another embodiment of the drive train which is similar to the one shown in the FIG. 6, but a clutch mechanism 117 is introduced on the output side. The output shaft 19 is connected to the clutch 117 which further connects with differential 13. There is a geared wheel 14 connected between the clutch 117 and the differential 13. The electric motor 40 does not drive the geared wheel 12. But instead, the electric motors 40 drives this geared wheel 14. Rest of the arrangement of the transmission 10, differential 20 and input powers sources 15 and 33 is same as shown in the figure 6.

[0058] FIG. 9 shows another modification of the drive train described in the FIG. 8 where the clutch mechanism 117 is replaced with the planetary gear 17. The output shaft 19 of the transmission drives the sun gear 17s of the planetary gear set 17. The ring gear 17r is driven by the electric motor 40. The planet carrier 17p is connected to the differential 13. Rest of the arrangement of the transmission 10, differential 20 and input powers sources 15 and 33 is same as shown in the figure 6.

[0059] Those skilled in the art would appreciate that the proposed drive train system provides multiple input and multiple output configurations, which allows easier and efficient integration of the transmission of the vehicles with various types of power sources such as ICE, electric motor-generator, and flywheel FLW, but not limited to the likes. Accordingly, the proposed drive train can be implemented in any fuel-only vehicle, hybrid vehicle, and/or electric vehicle, and can also be used to retrofit existing fuel-based vehicles with battery and electric motors to convert the fuel-based vehicles into hybrid vehicles.

[0060] It is to be further appreciated by a person skilled in the art that while various embodiments of the present disclosure have been described for application of the proposed drive train in vehicles, however, the proposed universal drive train can also be implemented in belt-driven CVT transmission in high power applications, and all such embodiments are well within the scope of the present disclosure, without any limitations.

[0061] Moreover, in interpreting the specification, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refer to at least one of something selected from the group consisting of A, B, C ....and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.

[0062] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.