Vehicle powertrain with inboard brake

Abstract

A powertrain for a vehicle is provided. The powertrain comprises a propulsion system for supplying a drive torque to wheels of the vehicle, at least one inboard brake for applying a brake torque to the wheels, and a torque distribution mechanism for selectively distributing brake torque and / or drive torque between at least a first drive shaft and a second drive shaft of the powertrain. The inboard brake and torque distribution mechanism are arranged along a common axis that is approximately parallel with the drive shafts.

Description

[0001] VEHICLE POWERTRAIN WITH INBOARD BRAKE

[0002] TECHNICAL FIELD

[0003] The present invention relates to a vehicle powertrain and more precisely to a vehicle powertrain with an inboard brake.

[0004] BACKGROUND

[0005] In a road vehicle, especially a passenger car, the powertrain plays a crucial role in generating and transmitting power to the wheels. A powertrain generally comprises a propulsion system, a transmission, a drive axle with drive shafts, and a differential- or torque distributing device. The propulsion system generates drive torque to the wheels and can include a combustion engine, an electric motor, or a hybrid system. Integration of a differential can allow the wheels to rotate at different speeds, while a torque vectoring device may be provided to more freely distribute drive torque to different wheels in order to enhance the driving dynamics of the vehicle.

[0006] A powertrain can further include inboard brakes that can be mounted inside the drivetrain rather than on the wheel hubs. Inboard brakes are primarily used in high- performance or racing vehicles since they allow the unsprung mass of the wheel hubs to be reduced. Other advantages with using inboard brakes is that they can be protected from stonechips, branches, etc. (mechanical impacts), they can reduce or eliminate external particle emissions, and they may improve aerodynamics around the wheels. . Despite the advantages of inboard brakes, there are still obstacles to overcome. Inboard brakes require more complex design, they take up space in the drivetrain and they can increase manufacturing costs. Generally inboard brakes are subject to much tougher conditions in terms of thermal stress due to restricted air flow around parts of the powertrain. Therefore, the brakes may require additional cooling to ensure that they do not overheat.

[0007] From the above it is understood that there is room for improvements where integration of inboard brakes into a powertrain is concerned . SUMMARY

[0008] An object of the present invention is to provide a new type of powertrain which is improved over prior art and which eliminates or at least mitigates the known drawbacks discussed above. More specifically, an object of the invention is to provide a powertrain with increased stability, more compact design, and / or where relevant components can be cooled more efficiently and / or that enables a more optimized package strategy of the powertrain within the vehicle.

[0009] These objects are achieved by the technique set forth in the appended independent claims with preferred embodiments defined in the dependent claims related thereto.

[0010] In a first aspect, a powertrain for a vehicle is provided. The powertrain comprises a propulsion system for supplying a drive torque to the powertrain, at least one inboard brake for applying a brake torque to the powertrain, and a torque distribution mechanism for selectively distributing brake torque and / or drive torque between at least a first drive shaft and a second drive shaft of the powertrain. The inboard brake and torque distribution mechanism can be arranged along a common axis being approximately parallel with the drive shafts. This is advantageous since it saves space, enables a more optimized package strategy, and simplifies cooling since the components are arranged close to each other in a linear fashion.

[0011] Preferably, the propulsion system is also arranged along the common axis. This can further enhance the space saving and packaging advantages and provide increased stability along the axis.

[0012] In one embodiment, the inboard brake is connected between the propulsion system and the torque distribution mechanism. This is advantageous since one inboard brake can be used to brake both drive shafts.

[0013] In one embodiment, the inboard brake and at least one of the torque distribution mechanism and the propulsion system have a common cooling system. This is advantageous since it allows for easier cooling of the components, and more efficient utilization of required cooling components.

[0014] In one embodiment, the inboard brake and at least one of the torque distribution mechanism and the propulsion system are arranged in a common wet environment. This is advantageous in that complexity is reduced, as no internal sealing of the wet environment is required.

[0015] In one embodiment, the inboard brake is disposed in a particle collector housing. This is advantageous since it prevents particles, which typically are generated during braking, from being released into the environment.

[0016] In one embodiment, the inboard brake and at least one of the torque distribution mechanism and the propulsion system are arranged in a common housing. This is advantageous since a desirable environment for the components can be delimited by the housing. This also provides for a very compact solution.

[0017] In one embodiment, the propulsion system is arranged substantially in the center between an end of the first drive shaft and an end of the second drive shaft. This is advantageous since it can improve weight distribution and increase stability.

[0018] In one embodiment, the propulsion system, the inboard brake and the torque distribution mechanism are arranged such that a center of mass is located substantially in the center between an end of the first drive shaft and an end of the second drive shaft. This is advantageous since it can improve weight distribution and increase stability.

[0019] In one embodiment, the powertrain further comprises a first planetary gear set connected between the propulsion system and the inboard brake. This is advantageous since it allows for desired speed reduction between the propulsion system and the inboard brake.

[0020] In one embodiment, the powertrain further comprises a second planetary gear set connected between the inboard brake and the torque distribution mechanism. This is advantageous since it allows for desired speed reduction between the inboard brake and the torque distribution mechanism.

[0021] In one embodiment, the torque distribution mechanism comprises a first torque distribution device and a second torque distribution device. The first and second torque distribution devices can be configured to selectively control a degree of brake torque and / or drive torque transmitted to the first and second drive shafts, respectively. This is advantageous since the powertrain can be more symmetrical with a torque distribution device on each side, which can increase stability. In one embodiment, the first and second drive shafts are axle shafts that transfer torque to a left wheel and right wheel, respectively. In this embodiment, the torque distribution mechanism can accordingly be a torque vectoring mechanism.

[0022] In one embodiment, the inboard brake can be a hydraulic brake, an electric brake, a disc brake, a friction brake, an electromechanical brake, a wet brake, a ball ramp brake, a drum brake, an air brake and / or a magnetic brake. Each brake type has its own advantages and disadvantages.

[0023] In one embodiment, the inboard brake also functions as a parking brake. This is advantageous since it reduces the number of brakes required.

[0024] According to a second aspect, a vehicle is provided. The vehicle comprises the powertrain according to the first aspect.

[0025] BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Embodiments of the invention will be described in the following; references being made to the appended diagrammatical drawings which illustrate non-limiting examples of how the inventive concept can be reduced into practice.

[0027] Fig. l is a schematic view of a vehicle according to one example.

[0028] Fig. 2 is a schematic view of the powertrain according to one embodiment.

[0029] Fig. 3 is a schematic view of the powertrain according to one embodiment.

[0030] Fig. 4 is a schematic view of the powertrain according to one embodiment.

[0031] Fig. 5 is a schematic view of the powertrain according to one embodiment.

[0032] Fig. 6 is a schematic view of the powertrain according to one embodiment.

[0033] Fig. 7 is a schematic view of the powertrain according to one embodiment.

[0034] Fig. 8 is a schematic view of the powertrain according to one embodiment.

[0035] Fig. 9 is a schematic view of the powertrain according to one embodiment.

[0036] Fig. 10 is a schematic view of the powertrain according to one embodiment adapted for four wheel drive.

[0037] Fig. 11 is a schematic view of the powertrain according to one embodiment adapted for four wheel drive.

[0038] Fig. 12 is a schematic view of the powertrain according to one embodiment adapted for four wheel drive. DETAILED DESCRIPTION OF EMBODIMENTS

[0039] Hereinafter, certain embodiments will be described more fully with reference to the accompanying drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the invention, such as it is defined in the appended claims, to those skilled in the art.

[0040] The term “connected” is defined as connected, although not necessarily directly, and not necessarily mechanically. Two or more items that are “connected” may be integral with each other. The terms “a” and “an” are defined as one or more unless this disclosure explicitly requires otherwise. The terms “substantially”, “approximately” and “about” are defined as largely, but not necessarily wholly what is specified, as understood by a person of ordinary skill in the art. The terms “comprise” (and any forms thereof), “have” (and any forms thereof), “include” (and any form thereof) and “contain” (and any forms thereof) are open-ended linking verbs. As a result, a device, system or that “comprises”, “has”, “includes” or “contains” one or more components, possesses those one or more components, but is not limited to possessing only those one or more components.

[0041] The expression “connected between” is used to describe the relative connection of components, such as the inboard brake, torque distribution mechanism, gear sets, propulsion system, etc. When a component B is “connected between” two other components A and C, this means that a connection path between component A and component C runs through B. The components are accordingly connected in the order A-B-C. The connection order does not necessarily correspond to the physical placement order of the components. However, in some embodiments, a component that is described as being “connected between” two other components is also physically arranged between said components.

[0042] The term “torque distribution” may refer to “torque vectoring” when the torque is distributed to the driving wheels. Accordingly, a torque distribution mechanism / device may in some embodiments be a torque vectoring mechanism / device. Torque distribution is used as a broader term to also encompass cases where torque is distributed between for instance a front- and rear drive axle. The torque distribution mechanism can include any devices and / or mechanisms that are known to be used for torque vectoring and any reference made to a torque distribution mechanism / device may also be applicable for a torque vectoring mechanism / device and vice versa.

[0043] Further, while some components of the powertrain, such as the inboard brake, torque vectoring mechanism and planetary gears may be described in reference to only one or more embodiments, the description of such components can also be applicable for equally or similarly named or numbered components of other embodiments. It should also be noted that the schematic views of Figs. 2-12 are provided to illustrate how the components of the powertrain 100 can be connected and positioned relative to each other. The means through which two components can be connected is not limited by these illustrations. For instance, a connection with a shaft 101, 102, 103, 104, 105a, 105b, 131, 132 could alternatively be an indirect connection that may include one or more torque transfer means, such as gears.

[0044] In Fig. 1 a schematic view of a vehicle 1 is shown. The vehicle 1 comprises a front axle and a rear axle. In the shown example each axle is provided with a powertrain 100. The powertrain 100 of the front axle is configured to provide propulsion and braking of the front axle, while the powertrain 100 of the rear axle is configured to provide propulsion and braking of the rear axle. It should be noted that according to the examples described herein, the vehicle 1 may comprise only one powertrain 100 arranged on the front or rear axle.

[0045] Fig. 2 shows a schematic view of a powertrain 100 according to one embodiment. The powertrain comprises a propulsion system 110 (an electrical machine, an internal combustion engine, etc.) for supplying a drive torque to the powertrain, an inboard brake 120 for applying a brake torque to the powertrain, and a torque distribution mechanism 130 for selectively distributing brake torque and / or drive torque between at least a first drive shaft 131 and a second drive shaft 132 of the powertrain.

[0046] In addition to being configured to supply drive torque, the propulsion system 110 can be configured to supply brake torque to the powertrain. Accordingly, the brake torque distributed by the torque distribution mechanism 130 can originate from either the propulsion system 110, the inboard brake(s) 120, or both. The degree of brake torque generated from the propulsion system 110 and from the inboard brake(s) 120 during a braking operation can be selectively controlled to optimize performance, efficiency, durability, etc.

[0047] The inboard brake 120 is arranged between the propulsion system 110 and the torque distribution mechanism 130. In the embodiments of Figs. 2-9, the torque distribution mechanism 130 is a torque vectoring mechanism 130 and the first and second drive shafts 131, 132 correspond to axle shafts that transfer torque from the torque vectoring mechanism 130 to a left wheel LW and a right wheel RW. In this case, the first and second drive shafts 131, 132 could be referred to as a left and right drive shaft 131, 132, respectively. The left and right wheels LW, RW can correspond to both front and rear wheels and accordingly, the powertrain 100 can be used for both front wheel drive FWD and rear wheel drive RWD. Alternatively, two powertrains, one for the front wheels and one for the rear wheels, can be used to achieve four wheel drive 4WD. It should also be noted that all embodiments described herein can also be mirrored such that the right wheel(s) switches places with the left wheel(s) and / or a front axle switches places with a rear axle.

[0048] As illustrated in Fig. 2, the inboard brake 120 and torque vectoring mechanism 130 are arranged along, and possibly concentric with, a common axis X. The common axis X is substantially parallel with the drive shafts 131, 132. When the powertrain 100 is arranged in a vehicle 1, the drive shafts 131, 132 generally extend along a lateral direction of the vehicle 1 which is perpendicular to a drive direction or longitudinal direction of the vehicle 1. Accordingly, the common axis X may be parallel with or correspond to an axis formed by connecting the left and right wheels LW, RW. Preferably, the position of the common axis X in the longitudinal direction of the vehicle 1 is close to or the same as the position of the drive shafts 131, 132 in the same longitudinal direction.

[0049] The propulsion system 110 can be a combustion engine, an electric motor or a hybrid system. The propulsion system 110 generates torque to a propulsion output shaft 101 that in turn transfers torque to a torque distribution input shaft 102. Any transfer of torque mentioned herein can take place through any known torque transfer means, such as gears, belts, chains, etc. The magnitude of the torque may change during transfer, for instance if torque is transferred through gears of different dimensions. During braking, a brake torque is applied to the torque distribution input shaft 102 using an inboard brake 120 and / or from the propulsion system 110. The brake torque and / or drive torque is then transferred to the first and second drive shafts 131, 132 via the torque vectoring mechanism 130. The first and second drive shafts 131, 132 in turn transfer the brake / drive torque to a left and right wheel, respectively. It should be noted that the drive shafts 131, 132 depicted in the figures are not necessarily formed by a single shaft, and each drive shaft 131, 132 could consist of many shafts connected by torque transfer means such as gears etc. For the embodiments shown in Figs. 2-9, an end 13 le, 132e of a drive shaft 131, 132 can be defined as a point where the drive shaft 131, 132 connects to the wheel.

[0050] In the example shown in Fig. 2, the inboard brake 120 and the torque vectoring mechanism 130 are implemented using multiplate disc clutches. The clutches may be hydraulically or electromechanically actuated.

[0051] Fig. 3 shows a similar embodiment of a powertrain 100 as Fig. 2. The embodiments differ in that the propulsion system 110 is also arranged along, and possibly concentric with, the common axis X and the propulsion output shaft and the torque distribution input shaft 101, 102 are formed by the same shaft.

[0052] In the embodiment shown in Fig. 4, the propulsion output shaft 101 and torque distribution input shaft 102 are instead connected via a first planetary gear set 141. In other words, the first planetary gear set 141 is connected between the propulsion system 110 and the inboard brake 120. The first planetary gear set 141 generally comprises a sun gear 144, two-stepped planet gears 145, a planet carrier 147 and a fixed ring wheel 146. The planet gears 145 held by the planet carrier 147 revolve around the sun gear 144 inside the ring wheel 146. The propulsion system 110 is connected to the sun gear 144 and the inboard brake 120 and subsequently the torque vectoring mechanism 130 is connected to the planet carrier 147. In this case, the propulsion output shaft 101 is connected to the sun gear 144 and the torque distribution input shaft 102 is connected to the planet carrier 147. The planetary gear set 141 is useful for achieving different torque between its input and output shafts, in this case the propulsion output shaft 101 and the torque distribution input shaft 102. Using the first planetary gear set 141, the torque of the torque distribution input shaft 102 can be adapted to a torque that is suitable for braking and / or operation of other components of the powertrain 100. In the embodiment shown in Fig. 4, the first planetary gear set 141 is also arranged along the common axis X, but an embodiment where the planetary gear set 141 is arranged excentric with regards to the axis X is also possible. For example, the first planetary gear set 141 could be arranged next to the propulsion system 110 of the embodiment shown in Fig. 2.

[0053] Fig. 5 shows a similar embodiment as Fig. 4 where the propulsion system 110, the first planetary gear set 141, the inboard brake 120 and the torque vectoring mechanism 130 are arranged in a common housing 161 that defines a wet environment 160. The inboard brake 120 is also confined in a particle collector housing 162. The particle collector housing 162 can form at least part or the common housing 161. While the particle collector housing 162 and the common housing 161 is illustrated together, embodiments where only one is present is well within the scope of this disclosure. The common housing 161 can also be configured to serve as a particle collector, for instance by sealing the components from the rest of the vehicle 1 such that particles cannot exit the housing 161. The common housing 161 may form a “sealed for life” system where no service is typically required. The wet environment 160 may be achieved by submerging the first planetary gear set 141, the inboard brake 120, the torque vectoring mechanism 130 and / or other relevant components of the powertrain 100 in oil and sealing them in the common housing 161. The inboard brake 120, the torque distribution mechanism 130 and the propulsion system 110 also have a common cooling system 150. Though not illustrated, the common cooling system 150 may also be shared with the first planetary gear set 141. The common cooling system 150 can also be at least partially arranged in the common housing 160. Alternatively or additionally, the common cooling system 150 may be configured to provide cooling to the entire system contained in the common housing 161. This can for instance take place by circulating a coolant through hoses arranged inside the common housing 161.

[0054] Fig. 6 shows a similar embodiment as Fig. 4 that further includes a second planetary gear set 142 connected between the inboard brake 120 and the torque vectoring mechanism 130. The second planetary gear 142 set can be constructed in a similar way and comprise similar components as the first planetary gear set 141, i.e. a sun gear 144, single step or two-stepped planetary gears 146, a planet carrier 147 and a stationary ring wheel 146. Here, the torque distribution input shaft 102 is connected to the planet carrier 147 of the second planetary gear set 142 and a first planetary gear set output shaft 103 connects the planet carrier 147 of the first planetary gear set 141 to the sun gear 144 of the second planetary gear set 142. The inboard brake 120 is configured to apply brake torque to the first planetary gear set output shaft 103. A drive torque or brake torque generated by the propulsion system 110 can be transferred though the propulsion output shaft 101, the first planetary gear set 141, the first planetary gear set output shaft 103, the second planetary gear set 141, the torque distribution input shaft 102 and then to the torque vectoring mechanism 130. Brake torque generated by the inboard brake 120 and / or propulsion system can be transferred from the first planetary gear set output shaft 103 along the same path to the torque vectoring mechanism 130. Accordingly, the torque vectoring mechanism 130 of this embodiment is configured for selectively distributing a drive torque and / or brake torque from the torque distribution input shaft 102 between the first drive shaft 131 and the second drive shaft 132.

[0055] Fig. 7 shows a similar embodiment as Fig. 6 where the inboard brake 120 is arranged on the opposite side (in this case to the right) of the propulsion system 110 as the torque vectoring mechanism 130 (in this case to the left). The first planetary gear set 141 is also illustrated as being arranged on the same side as the inboard brake 120, while the second planetary gear set 142 is arranged on the same side as the torque vectoring mechanism 130. However, a similar embodiment where one or both of the planetary gear sets 141, 142 have been removed is also possible. It is also possible for the second planetary gear set 142 to be arranged on the same side as the inboard brake 120. These variations can be readily envisioned by a skilled person. A potential advantage with such embodiments is that it can allow the propulsion system 110 to be arranged more centrally along the drive axle, which can increase stability. A common housing 161 and wet environment 160 for the propulsion system 110, the first planetary gear set 141 and the inboard brake 120 is also illustrated. Though not shown, the common housing 161 could extend further to also surround the second planetary gear set 142 and / or the torque vectoring mechanism 130. Like in previous embodiments, the propulsion output shaft 101 connects to the sun gear 144 of the first planetary gear set 141. The first planetary gear set output shaft connects the planet carrier 147 of the first planetary gear set 141 to the inboard brake. The inboard brake 120 in turn connects to the sun gear 144 of the second planetary gear set 142 via a brake output shaft 104. The torque distribution input shaft 102 then connects the planet carrier 147 of the second planetary gear set 142 to the torque distribution mechanism 130.

[0056] Fig. 8 shows an embodiment where the torque distribution mechanism 130 is divided into a first torque distribution device 130a and a second torque distribution device 130b arranged on opposing sides of the propulsion system 110. The propulsion output shaft 101 can extend on both sides of the propulsion system 110 or one propulsion output shaft 101 for each side can be provided. Instead of the torque distribution input shaft 102, a first torque distribution device input shaft 102a and a second torque distribution device input shaft 102b is provided. A propulsion output shaft 101 is configured to transfer torque to the first and / or second torque distribution device input shaft 102a, 102b. This can take place via one or more gears that may change the magnitude of the transferred torque. Alternatively, a propulsion output shaft 101 and the first and / or second torque distribution device input shaft 102a, 102b could be formed by the same shaft. The first and second torque distribution devices 130a, 130b are configured to selectively control a degree of drive torque and / or brake torque transmitted from the first or second torque distribution device input shafts 102a, 102b to a first and second torque distribution device output shaft 105a, 105b. The first and second torque distribution device output shaft 105a, 105b in turn transfer torque to the first and second drive shafts 131, 132. Accordingly, the first and second torque distribution devices 130a, 130b are, by extension, configured to selectively control a degree of drive torque and / or brake torque transmitted to the first and second drive shafts 131, 132, respectively. During a braking operation, the torque distribution devices 130a, 130b may be configured to not transfer any drive torque to the drive shafts 131, 132 and / or transfer brake torque from the propulsion system 110. Embodiments where the torque distribution device output shafts 105a, 105b are omitted and the torque distribution devices 130a, 130b transfer torque directly to the drive shafts 131, 132 are also possible. It is also possible for one or both the inboard brakes to be connected between the propulsion system 110 and a torque distribution device 130a, 130b. In that case, the torque distribution devices 130a, 130b could also be configured to transfer a brake torque from one of the inboard brakes 120. An advantage with embodiments described in reference to Fig. 8 can be increased stability and simplified design since left / right symmetry can be achieved.

[0057] Fig. 9 shows a similar embodiment as Fig. 8 but with a single inboard brake 120. The inboard brake 120 is arranged so it can apply a brake torque to the propulsion output shaft 101 extending on both sides of the propulsion system 110. A drive and / or brake torque can then be transferred from the propulsion output shaft 101 to the first and second torque distribution device input shafts 102a, 102b. Alternatively, the propulsion output shaft 101 and the first and second torque distribution device input shafts 102a, 102b can be formed by the same shaft. The torque distribution devices 130a, 130b are configured to selectively transfer drive / brake torque to the torque distribution device output shafts 105a, 105b and then to the drive shafts 131, 132. Just as with the embodiment of Fig. 8, a torque distribution device output shaft and a drive shaft may be formed by the same shaft.

[0058] The embodiments described above in reference to Figs. 2-9 can also be applied to a four wheel drive (4WD) propulsion system by having the drive axles 131, 132 extend longitudinally to connect to a front and rear axle that each connect to a left and right wheel LW, RW. Examples of how this can be realized is illustrated in Figs. 10-11. In these embodiments, the powertrain 100 illustrated in Fig. 3 has been expanded to 4WD by connecting each drive axle 131, 132 either to a front torque distribution mechanism 133 or a rear torque distribution mechanism 134 (Fig. 10) or to a front differential 135 or a rear differential 136 (Fig. 11). All other previously described embodiments could similarly be adapted to 4WD by connecting the drive shafts 131, 132 to a front and rear axles. In these cases, the ends 13 le, 132e of the drive shafts 131, 132 can be defined as a point where the drive shaft 131, 132 connects to the front or rear differential or torque distribution mechanism.

[0059] As illustrated in Figs. 10-11, the common axis X can still be parallel with the drive shafts 131, 132. Alternatively or additionally, the common axis X can be parallel to an axis formed by connecting the front left wheel to the rear left wheel or the front right wheel to the rear right wheel. The front and / or rear differentials and / or torque distribution mechanisms 133, 134, 135, 136 can also be arranged along the common axis X.

[0060] The front and rear torque distribution mechanisms 133, 134 shown in Fig. 10 are configured to selectively distribute a torque between a left axle shaft and a right axle shaft that connects to a left wheel and right wheel, respectively. In this way, the single inboard brake 120 can be used for generating brake torque that can be transmitted to all four wheels of a 4WD powertrain 100. The arrangement of the torque distribution mechanism 130, the front torque distribution mechanism 133 and the rear torque distribution mechanism 134 allows brake torque and / or drive torque to be selectively distributed between the four drive wheels.

[0061] Using a front and rear differential 135, 136 instead allows the left and right wheels to rotate at different speeds. The differentials 135, 136 can be limited slip differentials (LSD) and / or be equipped with a differential lock capable of locking the differential and forcing the left and right wheels to rotate at the same speed. Accordingly, a torque can be distributed between the front and rear wheels while the left and right wheels can be allowed to rotate at different speeds.

[0062] It should be noted that embodiments of the powertrain 100 utilizing a front differential 135 and a rear torque distribution mechanism 134 or a front torque distribution mechanism 133 and a rear differential 136 are also possible.

[0063] Fig. 12 illustrates another embodiment of a powertrain 100 adapted for 4WD. Starting from the embodiment illustrated in Fig. 3, the powertrain 100 further comprises a first auxiliary torque distribution mechanism 137 connected between the torque distribution mechanism 130 and the inboard brake 120. Accordingly, the propulsion output shaft 101 and the torque distribution input shaft 102 are separate shafts where the propulsion output shaft 101 connects the propulsion system 110 to the first auxiliary torque distribution mechanism 137 and the torque distribution input shaft 102 connects the first auxiliary torque distribution mechanism 137 to the torque distribution mechanism 130. The inboard brake 120 is configured to apply brake torque to the propulsion output shaft 101. The first auxiliary torque distribution mechanism 137 is configured to selectively distribute brake torque and / or drive torque between the torque distribution mechanism 130 and a second auxiliary torque distribution mechanism 138. This may be achieved by distributing brake torque and / or drive torque from the propulsion output shaft 101 between the torque distribution input shaft 102 and a second auxiliary torque distribution input shaft 105 connected to the second auxiliary torque distribution mechanism 138. The second auxiliary torque distribution mechanism 138 is in turn configured to distribute brake torque and / or drive torque between a left wheel LW and a right wheel RW, in this case corresponding to the front wheels. The torque distribution mechanism 130 is configured to distribute brake torque and / or drive torque between the other left and right wheels, LW and RW that are connected to the drive shafts 131, 132. The arrangement of the first auxiliary torque distribution mechanism 137, the second auxiliary torque distribution mechanism 138 and the torque distribution mechanism 130 allows brake torque and / or drive torque to be selectively distributed between the four drive wheels.

[0064] As illustrated in Fig. 12, the first auxiliary torque distribution mechanism 137 can also be arranged along the common axis X. Although not shown, the second auxiliary torque distribution mechanism 138 can also be arranged along the common axis X.

[0065] While the embodiments described with reference to Fig. 12 are based on the concept of the embodiment illustrated in Fig. 3, corresponding variations of embodiments described in reference to Figs. 2-7 adapted in the same way are also included within the scope of this disclosure. Such embodiments could be adapted by connecting a first auxiliary torque distribution mechanism 138 between the inboard brake 120 and the torque distribution mechanism 130. Other components for achieving 4WD, such as the second auxiliary torque distribution mechanism 138 could then be added. For embodiments comprising a second planetary gear set 142, the first auxiliary torque distribution mechanism 138 could be connected between this gear set and the torque distribution mechanism 130 or the inboard brake 120. It should be noted that the torque vectoring mechanisms 130, 133, 134, 135, 136, 137, 138 can be of both the same and different types.

[0066] While components such as the common housing 161, wet environment 160, particle collector housing 162 and common cooling system 150 is only illustrated in some embodiments, one or more of these components may be present in all embodiments. Other components of the powertrain 100 can also be arranged in the wet environment 160 and / or the common housing 100 and / or share the common cooling system 150. Such components can include one or more of the first planetary gear set 141, the second planetary gear set 142, the first torque distribution device 130a, the second torque distribution device 130b, the front torque distribution mechanism 133, the rear torque distribution mechanism 134, the front differential 135, the rear differential 136, the first auxiliary torque distribution mechanism 137 and the second torque distribution mechanism 138.

[0067] The inboard brake(s) 120 of any embodiment may also function as a parking brake(s). In this case, the inboard brake 120 maintains a braking engagement during parking, while the torque distribution mechanism 130 ensures that the torque path is closed

[0068] Modifications and other variants of the described embodiments will come to mind to one skilled in the art having benefit of the teachings presented in the foregoing description and associated drawings. Therefore, it is to be understood that the embodiments are not limited to the specific example embodiments described in this disclosure and that modifications and other variants are intended to be included within the scope of this disclosure. For example, while embodiments of the invention have been described with reference to a powertrain, persons skilled in the art will appreciate that the embodiments of the invention can equivalently be applied to a drivetrain. Furthermore, although specific terms may be employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. Therefore, a person skilled in the art would recognize numerous variations to the described embodiments that would still fall within the scope of the appended claims. Furthermore, although individual features may be included in different claims (or embodiments), these may possibly advantageously be combined, and the inclusion of different claims (or embodiments) does not imply that a combination of features is not feasible and / or advantageous. In addition, singular references do not exclude a plurality. Finally, reference signs in the claims are provided merely as a clarifying example and should not be construed as limiting the scope of the claims in any way.

Claims

CLAIMS1. A powertrain (100) for a vehicle, the powertrain comprising a propulsion system (110) for supplying a drive torque to wheels (LW, RW) of the vehicle; at least one inboard brake (120) for applying a brake torque to the wheels (LW, RW); and a torque distribution mechanism (130) for selectively distributing brake torque and / or drive torque between at least a first drive shaft (131) and a second drive shaft (132) of the powertrain (100), wherein the inboard brake (120) and torque distribution mechanism (130) are arranged along a common axis (X) being parallel with the drive shafts (131, 132).

2. The powertrain (100) according to claim 1, wherein the propulsion system (110) is arranged along the common axis (X).

3. The powertrain (100) according to any of the preceding claims, wherein the inboard brake (120) is connected between the propulsion system (110) and the torque distribution mechanism (130).

4. The powertrain (100) according to any of the preceding claims, wherein the inboard brake (120) and at least one of the torque distribution mechanism (130) and the propulsion system (110) have a common cooling system (150).

5. The powertrain (100) according to any of the preceding claims, wherein the inboard brake (120) and at least one of the torque distribution mechanism (130) and the propulsion system (110) are arranged in a common wet environment (160).

6. The powertrain (100) according to any of the preceding claims, wherein the inboard brake (120) is disposed in a particle collector housing (162).

7. The powertrain (100) according to any of the preceding claims, wherein the inboard brake (120) and at least one of the torque distribution mechanism (130) and the propulsion system (110) are arranged in a common housing (161).

8. The powertrain (100) according to any of the preceding claims, wherein the propulsion system (110), the inboard brake (120) and the torque distribution mechanism (130) are arranged such that a center of mass is located substantially in the center between an end (13 le) of the first drive shaft (131) and an end (132e) of the second drive shaft (132).

9. The powertrain (100) according to any of the preceding claims, further comprising a first planetary gear set (141) connected between the propulsion system (110) and the inboard brake (120).

10. The powertrain (100) according to any of the preceding claims, further comprising a second planetary gear set (142) connected between the inboard brake (120) and the torque distribution mechanism (130).11 . The powertrain (100) according to any of the preceding claims, wherein the torque distribution mechanism (130) comprises a first torque distribution device (130a) and a second torque distribution device (130b), wherein the first and second torque distribution devices (130a, 130b) are configured to selectively control a degree of brake torque and / or drive torque transmitted to the first and second drive shafts (131, 132), respectively.

12. The powertrain (100) according to any of the preceding claims, wherein the first and second drive shafts (131, 132) are axle shafts that transfer torque to a left wheel (LW) and right wheel (RW), respectively, and the torque distribution mechanism (130) is a torque vectoring mechanism.

13. The powertrain (100) according to any of the preceding claims, wherein the inboard brake (120) is a hydraulic brake, an electric brake, a disc brake, afriction brake, an electromechanical brake, a wet brake, a ball ramp brake, a drum brake, an air brake, an electromagnetic brake and / or a magnetic brake.

14. The powertrain (100) according to any of the preceding claims, wherein the inboard brake (120) also functions as a parking brake.

15. A vehicle (1), comprising the powertrain (100) according to any of the preceding claims.

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