TECHNICAL FIELD

The invention relates to a control device for a transmission of a powertrain. It further relates to a transmission assembly, a powertrain, and a vehicle.

The invention can be applied in heavy-duty vehicles, such as trucks, buses and construction equipment, and in particular in fully or partly electrified vehicles. Although the invention will be described with respect to a heavy-duty truck, the invention is not restricted to this particular vehicle, but may also be used in other vehicles such as light weight trucks, passenger cars, and working machines within the fields of industrial construction machines or construction equipment.

BACKGROUND

Transmission assemblies for vehicles, also known as gearboxes, are configured for providing controlled application of power, by use of a number of drivingly connected gear wheels, from an input shaft to an output shaft. The transmission assembly hence comprises one or more gear wheels for providing speed and torque conversions from a rotating power source to e.g. one or more driven axles of a vehicle.

The rotating power source, also referred to as propulsion unit, may be any kind of power source, such as an internal combustion engine and one or more electrical machines. The transmission assembly may hence be part of a powertrain for a vehicle which comprises the one or more power sources. It is for example known to provide a vehicle with at least two separate power sources, which may be electrical machines, where the power therefrom is provided via respective input shafts of the transmission assembly. Therefore such a transmission assembly may comprise at least two input shafts and at least one common output shaft.

With the development of using new power sources for vehicles, such as the above mentioned electrical machines, available space in the vehicle for accommodating the powertrain may be limited. Necessary components of fully or partly electrified vehicles, such as power converters, chargers, batteries, cables and cooling systems, require a lot of space. The space for accommodating the powertrain and the components thereof, for example the transmission assembly, may therefore be limited. It is therefore desirable to develop compact and space efficient transmission assemblies.

SUMMARY

A primary object of the invention is to provide a control device for a transmission and a transmission assembly, which are suitable for use in applications in which an available space is restricted. In particular, it is an object to provide such a control device and transmission assembly that are suitable for use in electrically operated vehicles and powertrains, such as in fully electrified vehicles or in hybrid vehicles.

According to a first aspect of the invention, the object is achieved by a control device for a transmission of a powertrain according to claim 1. The control device is configured to be mounted to a transmission housing of the transmission with a mounting surface of the control device abutting a corresponding abutment surface of the transmission housing, the control device comprising a set of actuators extending from a plane defined by the mounting surface of the control device, the control device being configured to handle gear shifts of the transmission by moving the actuators in an actuation direction so as to actuate gear shifting members. The actuation direction forms an angle a with respect to a direction perpendicular to the plane defined by the mounting surface, wherein -45° < a < 45°. By the provision of a control device in which the actuation direction of the actuators is non-parallel to the plane defined by the mounting surface, the control device may be mounted in a more space efficient manner on the transmission housing. Instead of being mounted on top of the transmission housing, with the mounting surface extending in parallel with one or more input shaft(s) of the transmission and with the actuators extending and being movable in a direction parallel to the mounting surface, the control device may be mounted with its mounting surface non-parallel to the input shaft(s). Thereby, it is possible to mount the control device at a position of the transmission housing where more space is available than right on top of the transmission, where the space is usually very restricted and where there is a risk that sensitive electronics within the control device become damaged, for example if the clearance is insufficient between the control device and a docking for a trailer, such as a fifth wheel.

The actuators are movable back and forth in the actuation direction, which may be parallel to the an axial direction of the input shaft(s). The actuation direction forms an angle of 45- 135° with respect to the plane defined by the mounting surface, i.e. the actuation direction may in some embodiments be perpendicular to the plane defined by the mounting surface. In this case, a = 0°. That the actuation direction extends at an angle a with respect to the direction perpendicular to the plane defined by the mounting surface should thus be understood to include the case when the angle a = 0° and the actuation direction consequently coincides with the direction perpendicular to the plane.

The mounting surface may be a bottom surface of the control device, from which the actuating cylinders extend. The mounting surface may extend entirely within the plane defined by the mounting surface, i.e. it may be a flat surface. However, the mounting surface may also be a surface extending only partly within the plane defined thereby, e.g. it may comprise a surface pattern or it may be a curved surface. In this case, the plane defined by the mounting surface is to be understood as a plane containing the outermost points of the mounting surface.

When mounted to the transmission housing, the mounting surface may be in direct contact with the abutment surface of the transmission housing, or e.g. a sealing member or similar may be provided in between the mounting surface and the transmission surface. It is to be understood that the transmission housing is provided with at least one opening through which the actuators extend when the control device is mounted to the transmission housing.

The control device may be configured to communicate with other electronic control units of the vehicle, such as an engine control unit or similar. It may thus comprise electronic circuitry configured for this purpose, and for controlling actuation of the actuators, directly or indirectly via pneumatics or hydraulics.

Optionally, -30°< a < 30°, or -20°< a < 20°, or -10°< a < 10°. An angle within these intervals, i.e. a relatively small angle, is beneficial for providing a compact and space efficient transmission assembly comprising the control device. Optionally, the actuation direction may be perpendicular to or essentially perpendicular to the plane defined by the mounting surface. In other words, the angle a is 0°, or essentially 0°, and the actuation direction consequently coincides with the direction perpendicular to the plane. This is particularly beneficial from a space efficiency point of view, since the control device can be mounted “vertically”, i.e. with the plane defined by the mounting surface extending perpendicularly to horizontally extending input and output shafts of the transmission. The control device may in such a position be better protected from impacts than when mounted on top of the transmission, i.e. mounted “horizontally”. By “essentially” is herein intended “within manufacturing tolerances”.

Optionally, the actuators may be in the form of actuating cylinders extending along the actuation direction. A longitudinal axis of each actuating cylinder thus extends in the actuation direction.

Optionally, the actuators may be pneumatic actuators, or hydraulic actuators, or electric actuators. The type of actuators may be selected so as to be compatible with other systems of the vehicle, e.g. pneumatic actuators may be suitable in a vehicle which is already equipped with a pneumatic system.

Optionally, the actuators may be configured to engage with gear shifting members of the transmission when the control device is mounted to the transmission housing. A distal end of the actuator, i.e. distal with respect to the mounting surface, may e.g. be provided with an engagement member, or docking member, adapted for engaging, or docking, with a corresponding engagement member, or docking member, provided on the gear shifting member. This facilitates mounting of the control device to the transmission housing. The gear shifting members of the transmission may e.g. be shift forks or similar, wherein the corresponding engagement member may be formed on a shift fork rod of the shift fork.

Alternatively, the control device may comprise gear shifting members connected to the actuators. At least one gear shifting member and a corresponding one of the actuators may in this case be formed as separate components or as an integrated component, formed in one piece.

According to a second aspect of the invention, at least the primary object is achieved by a transmission assembly for a powertrain of a vehicle, comprising: - a transmission comprising at least one input shaft configured to be drivingly connected to at least one propulsion unit of the powertrain, at least one output shaft configured to be drivingly connected to at least one driving axle of the vehicle, and a set of gears configured for transmission of torque from the at least one input shaft to the at least one output shaft,

- a set of gear shifting members for selectively engaging at least one gear of the set of gears,

- a transmission housing enclosing the transmission;

- a control device according to the first aspect of the invention mounted to the transmission housing with the mounting surface of the control device abutting a corresponding abutment surface of the transmission housing, wherein each one of the actuators is arranged to actuate at least one of the gear shifting members.

Advantages and advantageous features of the transmission assembly according to the second aspect are largely analogous to advantages and advantageous features of the control device according to the first aspect. It shall also be noted that each embodiment of the second aspect of the invention is applicable with each embodiment of the other aspects of the invention and vice versa.

Optionally, the direction perpendicular to the plane defined by the mounting surface forms an angle b with respect to an axial direction of the at least one input shaft and/or of the at least one output shaft, wherein -45° < b < 45°. Optionally, -30°< b < 30°, or -20°< b < 20°, or -10°< b < 10°. Optionally, the angle b=0°.

The angle b may coincide with the previously described angle a formed between the actuation direction and the direction perpendicular to the plane defined by the mounting surface. Thus, the actuation direction of the actuators may be parallel to or essentially parallel to an axial direction of the at least one input shaft.

Optionally, the abutment surface of the transmission housing extends in a direction that is perpendicular to or essentially perpendicular to an axial direction of the at least one input shaft. The abutment surface may herein be parallel to the plane defined by the mounting surface, so that the at least one input shaft extends in a direction perpendicular to or essentially perpendicular to the plane defined by the mounting surface. According to a third aspect of the invention, at least the primary object is achieved by a powertrain for a vehicle, comprising at least one propulsion unit and a transmission assembly according to the second aspect of the invention. It shall also be noted that each embodiment of the third aspect of the invention is applicable with each embodiment of the other aspects of the invention and vice versa.

Optionally, the at least one propulsion unit comprises at least one electric machine. The powertrain may alternatively or additionally comprise at least one internal combustion engine or another type of combustion unit.

Optionally, the at least one propulsion unit comprises at least two electric machines, i.e. the powertrain comprises at least two electric machines configured for powering the vehicle. In this case, the transmission assembly comprises at least two input shafts.

According to a fourth aspect of the invention, at least the primary object is achieved by a vehicle comprising a transmission assembly according to the second aspect of the invention, and/or a powertrain according to the third aspect of the invention. The vehicle may be a fully electrified vehicle, a hybrid vehicle, or a vehicle powered solely by an internal combustion engine. The vehicle may e.g. be a heavy-duty vehicle such as a bus, a truck, or a construction machine.

Further advantages and advantageous features of the invention are disclosed in the following description and in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

With reference to the appended drawings, below follows a more detailed description of embodiments of the invention cited as examples.

In the drawings:

Fig. 1 is a schematic side view of a vehicle according to an embodiment of the invention,

Fig. 2 is a perspective view of a transmission assembly according to an embodiment of the invention, Fig. 3 is a perspective view of parts of a transmission assembly according to an embodiment of the invention, Fig. 4 is another perspective view of the transmission assembly shown in fig. 3 Fig. 5 is a sectional view along the plane illustrated in fig. 2, Fig. 6 is a schematic side view of a control device according to an embodiment of the invention.

The drawings show diagrammatic exemplifying embodiments of the present invention and are thus not necessarily drawn to scale. It shall be understood that the embodiments shown and described are exemplifying and that the invention is not limited to these embodiments. It shall also be noted that some details in the drawings may be exaggerated in order to better describe and illustrate the invention. Like reference characters refer to like elements throughout the description, unless expressed otherwise. DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

A vehicle 100 in the form of a heavy-duty truck according to an embodiment of the invention is schematically shown in fig. 1. The vehicle 100 includes a powertrain 3 with two propulsion units 20, 21 in the form of electric machines for propulsion of the vehicle 100. The electric machines 20, 21 are connected to a transmission assembly 10. The transmission assembly 10 is arranged to transfer torque from the electric machines 20, 21 to a drive shaft 23 drivingly connecting the transmission assembly 10 to a driving axle 22 that drives driving wheels 24 of the vehicle 100. Thus, in the shown embodiment, the vehicle 100 is a fully electrified vehicle configured to be driven solely by the electric machines 20, 21. The vehicle 100 may be arranged with more than one driving axle, such as two or more driving axles. The vehicle 100 may comprise more than two electric machines, such as three or four electric machines. The vehicle may also be a hybrid vehicle, provided with a combustion engine in addition to at least one electric machine, or it may be a vehicle powered solely by an internal combustion engine. The electric machines may be in the form of electric motors/generators. The propulsion units and the transmission assembly may of course also be located at a different position within the vehicle than in the shown embodiment.

Fig. 2 schematically shows how the electric machines 20, 21 may be positioned with respect to the transmission assembly 10 according to an embodiment of the invention. The transmission assembly 10 comprises a transmission housing 12 and a control device 1 for handling gear shifts, which control device 1 is mounted to the transmission housing 12. The transmission housing 12 encloses a transmission (not shown in fig. 2) via which torque may be transmitted from the electric machines 20, 21 to the drive shaft 23 shown in fig. 1.

A transmission 2 and a control unit 1 according to an embodiment of the invention are schematically illustrated in figs. 3-5. In figs. 3 and 4, the transmission housing 12 has been omitted in order to clearly show the transmission 2 enclosed therein. The transmission 2 comprises two input shafts 11a, 11b, each one configured to be drivingly connected to one of the electric machines 20, 21 as illustrated in fig. 2. The input shafts 11a, 11b extend in an axial direction C. The transmission 2 further comprises an output shaft 13, parallel with the input shafts 11a, 11b. The output shaft 13 is configured to be drivingly connected to the driving axle 22 of the vehicle 100 via at least the drive shaft 23 (see fig. 1), and a set of gears 14 configured for transmission of torque from the input shafts 11a, 11b to the output shaft 13. Various configurations of the transmission are possible, which are well-known to the person skilled in the art. The transmission may for example comprise a plurality of input gears and output gears of varying gear ratios, and it may also comprise a range gear, such as a planetary gear set. It may further comprise one or more intermediate shafts provided between the input shafts and the output shaft.

In the shown embodiment, the transmission assembly 10 comprises three gear shifting members 15, 16, 17 for selectively engaging and disengaging gears of the set of gears 14. Each gear shifting member 15, 16, 17 comprises a shift fork 15a, 16a, 17a and a shift fork rod 15b, 16b, 17b extending from the shift fork 15a, 16a, 17a in a direction parallel to the axial direction C of the input shafts 11a, 11b. Each shift fork rod 15b, 16b, 17b is at a distal end thereof connected to an actuator 5, 6, 7 of the control device 1 , so that each one of the actuators 5, 6, 7 is arranged to actuate a corresponding one of the gear shifting members 15, 16, 17. The actuators 5, 6, 7 extend perpendicularly from a mounting surface 4 of the control device 1 , which mounting surface 4 abuts a corresponding abutment surface 18 of the transmission housing 12. Thus, the actuators 5, 6, 7 extend from the mounting surface 4 toward the gear shifting members 15, 16, 17 in a direction parallel to the axial direction C of the input shafts 11a, 11b. The actuators 5, 6, 7 are herein in the form of pneumatic actuating cylinders configured to be moved telescopically in the axial direction C of the input shafts 11a, 11b and the output shaft 13 by means of pressurized gas provided via pneumatic valves (not shown). At a distal end thereof, each actuator 5, 6, 7 comprises an engagement member 5c, 6c, 7c which is received by a corresponding receiving member 15c, 16c, 17c of each corresponding gear shifting member 15, 16, 17, such that movement back and forth of the actuator 5, 6, 7 results in a corresponding movement of the corresponding gear shifting member 15, 16, 17.

By positioning the control device 1 “vertically”, with its mounting surface 4 extending perpendicularly to the axial direction C of the input shafts 11a, 11b and the output shaft 13 such as shown in figs. 2-5, a space efficient configuration may be achieved, since the control device does not need to be mounted above the transmission housing 12, where the available space may be very limited. The vertically positioned control device 1 , and sensitive electronics included therein, is also better protected from impacts than a control device mounted above the transmission housing 12, with its mounting surface extending in parallel with the axial direction of the input shafts and the output shaft.

Fig. 6 is a schematic side view of a control device 1 according to an embodiment of the invention. The control device 1 is configured to handle gear shifts of a schematically shown transmission 2 by moving the actuators 5, 6, 7 in an actuation direction A so as to actuate gear shifting members (not shown). The control device 1 is configured to be mounted to a transmission housing 12 of the transmission 2 with a mounting surface 4 of the control device 1 abutting a corresponding abutment surface 18 of the transmission housing 12. The mounting surface 4 of the control device 1 defines a plane P, which is herein parallel with the mounting surface 4 and with the abutment surface 18. The actuators 5, 6, 7 extend in the actuation direction A from the plane P defined by the mounting surface 4. The actuation direction A forms an angle a with respect to a direction B, the direction B being perpendicular to the plane P defined by the mounting surface 4, wherein -45° < a < 45°. In various embodiments, -30°< a < 30°, or -20°< a < 20°, or - 10°< a < 10°. In the embodiment shown in figs 3-5, the angle a=0°, and the actuation direction A is thereby parallel to the direction B. The direction B, perpendicular to the plane P defined by the mounting surface 4, furthermore forms an angle b with respect to an axial direction C of input shafts 11a, 11b of the transmission 2, wherein -45° < b < 45°. In various embodiments, -30°< b < 30°, or - 20°< b < 20°, or -10°< b < 10°. In the embodiment shown in figs 2-5, the angle b=0°, and the actuation direction A is thereby parallel to the direction B. The angle b may be equal to the angle a such that the actuation direction A is parallel to the axial direction C of the input shafts 11a, 11b, such as shown in figs. 3-5.

The abutment surface 18 of the transmission housing 12 herein extends in a plane which is parallel to the plane P. When mounting the control device 1 to the transmission housing 12, the actuators 5, 6, 7 extend through an opening 19 formed in the transmission housing 12 such that the actuators 5, 6, 7 may engage with gear shifting members (not shown) so as to selectively engage gears for transmission of torque from the input shafts 11a, 11b to an output shaft (not shown).

The control device 1 according to embodiments of the invention as shown in figs. 2-6 may be mounted “vertically” or at an angle of up to 45° with respect to the transmission housing 12 and the input and output shafts 11a, 11b, 13 of the transmission 2, thereby avoiding “horizontal” placement on top of the transmission housing and enabling a more space efficient placement.

The control device 1 may also preferably comprise an electronic control unit (not shown) for controlling movement of the actuators 5, 6, 7 such as to effectuate gear shifts. The transmission assembly 10 may thus be an automated manual transmission or an automatic mechanically engaged transmission (AMT) for a vehicle, such as a truck. The control device 1 may comprise at least one communication interface 26 for communicating with other units within the vehicle, such as with various sensors, systems and control units, in particular with one or more electronic control units (ECUs) controlling electrical systems or subsystems in the vehicle, such as an engine control unit. The control device 1 may be configured to communicate wirelessly or via a hardwire system, such as in the embodiment shown in figs. 2-5.

In the embodiment shown in figs. 2-5, the control device 1 comprises pneumatic valves (not shown) for pneumatically operating the actuators 5, 6, 7. In this case, the control device 1 is configured for connection to a pneumatic system of the vehicle and the electronic control unit of the control device 1 controls the actuators 5, 6, 7 by controlling the pneumatic valves. Alternatively, the actuators may be electrically or hydraulically operated. In the embodiment shown in figs. 3-5, the control device 1 is mounted to the transmission housing 12 using a plurality of fastening members 25. Of course, as the skilled person will recognize, different means for mounting the control device to the transmission housing may alternatively be used. It is to be understood that the present invention is not limited to the embodiments described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the appended claims.