DE102023116235B3 - Torque vectoring transmission unit with an actuating device and motor vehicle - Google Patents

Abstract

The invention relates to an actuation system (1) for a torque vectoring transmission unit (2). By means of a disk connection device (48), an outer ring disk (9) and an inner disk (10) are mounted on one another in a rotationally fixed manner and axially displaceable relative to one another to form an actuation disk (8), which is arranged opposite a bearing block (36) and can be rotated relative to it. Rolling elements (41) are mounted between the bearing block (36) and the actuation disk (8) in rolling element tracks (43, 44, 45, 46) having ramps (51, 52, 53, 54). The outer ramps (51, 52) and the inner ramps (53, 54) differ from one another in terms of a ramp configuration, so that by rotating the actuating disk (8) in relation to the bearing block (36), the outer ring disk (9) and the inner disk (10) are moved axially in different directions along the longitudinal center axis (42). In this way, brakes (3, 4) of the transmission unit (2) are actuated in order to create particularly efficient torque vectoring. The invention also relates to a motor vehicle having the transmission unit (2).

Description

The present invention relates to a torque vectoring transmission unit with an actuation system for actuating two switching elements of the transmission unit, for example a brake and/or clutch pair. The invention further relates to a motor vehicle having such a transmission unit.

Electrically driven motor vehicles are characterized by high drive power (peak power), high starting torques from a standstill and high torque dynamics. However, a traction battery is required on board such a motor vehicle, which makes the motor vehicle particularly heavy, which leads to increased inertia (particularly around the vertical axis) of the vehicle. For example, it is known to use an electric drive unit for each drive axle. This comprises an electric drive motor, a single- or multi-stage transmission and a differential to distribute torque to the left and right wheels (tire-rim combination) of the drive axle. The wheel with the lower traction potential limits the torque output at the opposite wheel due to the open differential.

For sporty applications, mechanical, passive limited-slip differentials are conceivable to increase traction (particularly for accelerating out of curves and when one side is slippery/dirty). However, the locking effect causes the vehicle to understeer in an undesirable way, and increased steering effort is required to turn the wheels on the steered axle of the vehicle. Torque vectoring systems are used to compensate for the increased vehicle moment of inertia around the vertical axis caused by the high battery weight and to achieve agile driving behavior in sporty, electrically driven vehicles. Torque vectoring is the active and targeted delivery of drive torque to both wheels of the drive axle. Torque vectoring supports steering and makes even heavy vehicles and sluggish vehicles tuned for comfort appear dynamic and agile. Torque vectoring directs the drive torque more strongly to the wheels on the outside of the curve. A control unit with appropriate sensors, such as wheel speed sensors, can detect a difference in the speed of the wheels and meter and deliver the torque to each wheel individually. This can also result in particularly agile driving behavior for the appropriately equipped motor vehicle. In other words, torque vectoring systems generate yaw moments by delivering drive torque to the wheels asymmetrically. This can be achieved, for example, by using an electric drive motor for each wheel individually for each drive axle, so that a differential is not required. Torque vectoring concepts are also known in which, compared to a conventional electric drive, the differential is replaced by a superposition differential, in which a second, smaller electric motor can superimpose difference speeds between the left and right wheels and thus shift the torque delivery between the left and right wheels according to the wheel slip curves. Such a second electric machine is referred to, for example, as a secondary drive motor or torque vectoring machine and provides approximately 10% of the power of the primary drive motor.

However, the problem so far is that drives with two equally sized electric motors are not only expensive, but also take up a lot of mass and space. Furthermore, such drives are constructed fundamentally differently than drives with just one electric motor with a differential. As a result, a longitudinal and/or transverse modular system cannot be used in series production. In acceleration situations in which a wheel encounters low traction conditions, the electric motor that drives this wheel can only be operated with limited power. In extreme situations, this can mean that only 50% of the total system power is available to accelerate the vehicle. For drives with a superposition differential and with the secondary drive motor mentioned above, considerable effort is required to integrate the secondary drive motor into the drive. Since this differs greatly from the primary drive motor, a separate control system and separate power electronics are required for the secondary drive motor. The power provided by the secondary drive motor cannot be converted into propulsion for the vehicle, and the traction battery is subjected to additional strain. Furthermore, the structure of a planetary differential is complicated.

The EN 10 2012 017 352 A1 proposes a drive device for an electrically driven axle of a motor vehicle. The drive device has an electric machine, a transmission gear and a differential (in particular a spur gear differential) which drives to the driven wheels of the motor vehicle via output shafts. The transmission gear is formed by two planetary gears (in particular minus gears) which are coupled to one another and which can be switched to two transmission stages via switching elements (in particular brakes), whereby the brakes can be designed to be electrically or hydraulically actuated.

The EN 10 2013 206 757 A1 discloses a differential gear with a gear housing, a planetary housing that is mounted in the gear housing so that it can rotate about a gear axis, a planet carrier that sits in the planetary housing, and a first and a second output sun gear that is arranged in the planet carrier coaxially to the gear axis. Through this differential gear, the drive power applied to the planetary housing is branched to the first and second output sun gear with a temporary superposition of a coupling torque generated as a friction torque. The differential gear also comprises a braking device for generating a bridging torque that loads the relative rotation of the output sun gears in accordance with an axial force acting on the braking device, and an adjusting mechanism (in particular with a ramp mechanism) for generating the axial force acting on the braking device. The adjusting mechanism is designed in such a way that the bridging torque generated by the braking device increases as the drive torque acting on the planetary housing increases.

In addition, the CN 113 217 600 A an automotive differential gear with a torque vector distribution function is known. The differential gear includes a main reduction gear, a differential gear case, a first half shaft, a second half shaft, a double planetary, a double row TV clutch mechanism, a first brake, a second brake. A Simpson planetary gear train is used as the double planetary row TV clutch mechanism. By controlling the operating states of the first brake and the second brake, the differential mechanism can be switched between a normal straight-ahead or a normal torque vector distribution driving mode, a left-hand drive torque vector distribution driving mode, and a right-hand drive torque vector distribution driving mode.

The EP 3 184 840 B1 discloses a ball ramp mechanism having a control ring and an activation ring, the activation ring having a first portion and a second portion. The first portion has a radially inner surface and a radially outer surface and a plurality of keyways formed on the radially inner surface. The second portion has a radially inner surface and a radially outer surface and a plurality of keyways formed on the radially outer surface that are in direct rotationally fixed and axially movable engagement with the plurality of keyways on the radially inner surface of the first portion of the activation ring. A first circumferential plate groove is formed between the control ring and the first portion of the activation ring, and a second circumferential plate groove is formed between the control ring and the second portion of the activation ring. A plurality of rolling elements are disposed between the control ring and the activation ring in the circumferential plate grooves. The first portion of the activation ring is arranged to rotate axially in a first rotational direction while the second portion of the activation ring remains stationary, wherein the second portion of the activation ring is arranged to rotate axially in a second rotational direction opposite to the first rotational direction and the first portion of the activation ring remains stationary.

The object of the present invention is to provide torque vectoring functionality to an electric drive axle of a motor vehicle having only one electric machine and to be able to control it as simply and/or with as little effort as possible.

This object is achieved by the subject matter of the independent patent claims. Further possible embodiments of the invention are disclosed in the subclaims, the description and the figures. Features, advantages and possible embodiments that are set out in the description for one of the subject matter of the independent claims are to be regarded, across categories and embodiments, at least analogously as features, advantages and possible embodiments of the respective subject matter of the other independent claims and any possible combination of the subject matter of the independent claims, if applicable in conjunction with one or more of the subclaims.

According to the invention, a torque vectoring transmission unit for a motor vehicle is proposed, wherein the transmission unit has an actuation system by means of which two torque vectoring switching elements of the torque vectoring transmission unit can be actuated to distribute torque between wheels of the motor vehicle that have the same axle. The invention also includes a motor vehicle or an electric drive axle for a motor vehicle, wherein the motor vehicle or the drive axle has only one electric traction machine and the torque vectoring transmission unit.

The actuation system of the torque vectoring transmission unit (hereinafter referred to as the transmission unit) has an actuation disk which is made in two parts, namely an outer ring disk and a separately manufactured inner disk, in particular inner ring disc. In the gear unit, one of the torque vectoring switching elements (hereinafter referred to as switching elements) is mechanically coupled to the outer ring disc and the other of the switching elements is mechanically coupled to the inner disc. The outer ring disc has an outer disc rolling element track, whereas the inner disc has an inner disc rolling element track. The actuating disc also has a disc connecting device, by means of which the outer ring disc and the inner disc are mounted on one another in a rotationally fixed manner and axially displaceable relative to one another in relation to a longitudinal center axis of the actuating system. In the gear unit, its main gear axis and the longitudinal center axis of the fastening system can coincide. The actuating system also comprises a bearing block which has an outer bearing block rolling element track and an inner bearing block rolling element track. The outer ring and inner discs share their coinciding longitudinal center axes with a longitudinal center axis of the bearing block. The outer bearing block rolling element track and the outer disc rolling element track face each other axially with the same radius, whereby the inner bearing block rolling element track and the inner disc rolling element track face each other axially with the same radius. Rolling elements of the actuation system and the rolling element tracks are coordinated with each other with regard to a respective cross-section, so that the rolling elements can roll or roll in the respective rolling element track and in particular are laterally guided by means of the rolling element tracks. Tapered rollers or balls, for example, are suitable as rolling elements. One of the rolling elements is therefore inserted into the outer rolling element tracks and another of the rolling elements is inserted into the inner rolling element tracks. In particular, the balls are secured by means of a cage. One or both of the outer rolling element tracks has/have an outer ramp and one or both of the inner rolling element tracks has/have an inner ramp. The outer and inner ramps differ in their respective ramp configurations, so that by rotating the actuating disk in relation to the bearing block, the outer ring disk and the inner disk are moved axially in different ways along the longitudinal center axis. For example, the outer ramp differs from the inner ramp in terms of a different ramp angle, a different ramp height, a different positional location, a different angular position in relation to the bearing block, an opposite orientation, a different ramp shape, etc. Although only one outer and one inner disc rolling element track and only one outer and one inner bearing block rolling element track are addressed here, the fastening system can have two or more inner/outer disc rolling element tracks and accordingly two or more inner/outer bearing block rolling element tracks.

The ramps and the rolling element tracks are designed and arranged in such a way that - starting from an initial or neutral position of the actuating system, in which both disks axially abut the bearing block - the outer ring disk is moved axially away from the bearing block when the actuating disk is rotated in a first direction of rotation in relation to the bearing block. In contrast, starting from the neutral position, the inner disk is moved axially away from the bearing block when the actuating disk is rotated in a second direction of rotation opposite to the first direction of rotation in relation to the bearing block. In addition, the ramps and the rolling element tracks are designed and arranged in such a way that, starting from the neutral position - when the actuating disk is rotated in the first direction of rotation in relation to the bearing block - the inner disk remains axially motionless while the outer ring disk is moved, i.e. it remains in the neutral position. If, however, the actuating disc is rotated in the second direction of rotation in relation to the bearing block, the outer ring disc remains axially stationary, abutting or resting against the bearing block while the inner disc moves.

For the torque vectoring functionality, a spur gear differential based on a planetary plus gear is used (functionally identical to a bevel gear differential), which is combined with two small minus planetary gears and two controlled brakes (such as multi-disk clutches or brakes). Other types of frictionally acting brakes or clutches are conceivable, for example band brakes, dry single or multi-disk clutches, etc. The transmission unit therefore has a primary differential, a secondary differential and a tertiary differential, each of which is designed as a planetary gear. The transmission unit also has the actuation system in which the disks of the actuation disk are individually deflected from the neutral position depending on the direction of rotation, with the corresponding other of the disks remaining axially stationary. Furthermore, the following aspects belong to this development of the transmission unit: A transmission drive element is formed by a primary ring gear of the primary differential, which means that when the transmission unit is in operation, torque and speed are introduced into the transmission unit via the primary ring gear by means of a drive machine, in particular an electric drive machine. A single or multi-stage transmission can be provided between the drive machine and the primary ring gear. A primary planet carrier of the primary differential is connected to a first transmission output shaft, wherein a first primary sun gear of the primary differential is connected to a second transmission output shaft. In addition, the primary differential has a second primary sun gear. A first and a second primary planet gear are mounted on the primary planet carrier, the first primary planet gear meshing with both the first primary sun gear and the second primary planet gear and not with the primary ring gear. The second primary planet gear meshes with the second primary sun gear, the first primary planet gear and the primary ring gear. It can be seen that the primary differential is designed in the Ravigneaux design. The second primary sun gear is connected to a secondary ring gear of the secondary differential, a secondary sun gear of the secondary differential being brakeable by means of a secondary brake of the transmission unit, which is mounted in a rotationally fixed manner on a transmission housing. A secondary planet carrier of the secondary differential is connected on the one hand to the second transmission output shaft and on the other hand to a tertiary ring gear of the tertiary differential. A tertiary sun gear of the tertiary differential can be braked by means of a tertiary brake of the transmission unit, which is mounted on the transmission housing in a rotationally fixed manner, and a tertiary planet carrier of the tertiary differential is connected to the secondary ring gear. The brakes are each mechanically coupled separately to one of the disks of the actuating disk. This means that the secondary brake is coupled, for example, to the outer ring disk or can be actuated by disengaging the outer ring disk from the neutral position. In this case, the tertiary brake is then coupled to the inner disk or can be actuated by disengaging the inner disk from the neutral position. A reverse arrangement is of course conceivable. As a result, starting from the neutral position of the actuating system, the secondary brake or the tertiary brake is actuated depending on the direction of rotation of the actuating disk. In this way, the transmission unit provides a torque vectoring functionality that is implemented using particularly simple means and is particularly easy to control.

Thanks to the actuation system, the two switching elements of the transmission unit can be actuated particularly efficiently to distribute torque between wheels of the motor vehicle that are on the same axle. In addition, the actuation system is particularly compact and simple in terms of its structure. By designing or laying out the ramps of the actuation system accordingly, the switching elements can be controlled or actuated as required using simple means. As can be seen from the above explanation, only one actuation system needs to be used to control/actuate both switching elements. Thanks to the design and arrangement of the ramps described above, the two switching elements can be actuated individually, so that torque can be distributed particularly efficiently between the wheels of the drive axle. To do this, the actuation disk and the bearing block only need to be turned in the appropriate direction relative to each other.

According to another possible embodiment, the actuation system has exactly one actuator that is coupled to the bearing block or to the actuation disk and is designed to rotate the actuation disk around the longitudinal center axis in relation to the bearing block. This advantageously makes it possible to dispense with two separate actuators for separately actuating the two switching elements. This results in particularly simple control of the torque vectoring functionality of the transmission unit.

According to another possible embodiment, the bearing block or the actuating disk has an external gear ring, with a gear of the actuator meshing with the external gear ring. In one possible embodiment, the gear of the actuator is designed as a worm gear. This allows a particularly advantageous packaging of the gear unit to be achieved, and the actuating disk or the bearing block can be driven particularly efficiently by means of the actuator, i.e. can be rotated. The actuator gear thus formed between the actuator and the bearing block or the actuating disk can be single-stage or multi-stage. In particular, the actuator gear can have a spur gear set, in particular a planetary gear set.

In a possible further development, an external rotary joint structure is arranged on an outer peripheral surface of the inner disk, which engages in a rotationally fixed and axially movable manner in an inner rotary joint structure arranged on an inner peripheral surface of the outer ring disk and corresponding to the external rotary joint structure. For example, an outer wedge structure is arranged on the outer peripheral surface of the inner disk, with an inner wedge structure corresponding to the outer wedge structure being arranged on the inner peripheral surface of the outer ring disk. The outer wedge structure then engages in the inner wedge structure in a rotationally fixed and axially movable manner, whereby a spline is formed between the inner disk and the outer ring disk. Other designs of the rotary structures are just as conceivable, for example a tongue and groove connection can be made between the inner and outer disks, or the inner peripheral surface and the outer peripheral surface can have a straight cylindrical or straight prismatic shape that deviates from a circle.

Operation of the transmission unit, in particular driving the vehicle equipped with the transmission unit is as follows: Depending on whether more torque (speed) is to be applied to the left or right wheel, the secondary or tertiary brake is applied or regulated. If, in an extreme case, there is no difference in speed between the applied brake and the gearbox housing, the sun gear of the pallet differential coupled to the brake in question is at work, which then acts as the gear ratio between the left and right wheels. A possible gear ratio i between the left and right wheels is, for example, i = 0.75 to i = 1.25, preferably i = 0.80 to i = 1.25. The left wheel then only rotates at 75% of the speed of the right wheel, for example. In combination with wheel slip curves, this leads to a strong braking effect on the left wheel and a strong pulling effect on the right wheel. The different drive torques on the left and right lead to a yaw moment about the vertical axis of the vehicle, which actively turns it into or out of the curve. If the brake is released again and the other brake is applied, the relationships between left and right are reversed.

For operation of the transmission unit, it is particularly intended that the two brakes are operated in slip mode. If the actuation system has the actuator, the delta wheel torque can be regulated or controlled by regulating or controlling the axial actuation force and the driving behavior can be sensitively influenced.

As already mentioned, the two brakes are controlled by means of two coupled, radially superimposed ring-shaped ball ramps that are only controlled by one actuator. Non-rotating parts of the ball ramps are connected to the gearbox housing in a rotationally fixed manner; for example, the bearing block is fixed to the gearbox housing, or the bearing block can be formed by the gearbox housing. The actuator drives the actuating disk in relation to the positionally fixed bearing block via the actuator gear (ratio approx. i = 1:25 to i = 1:125, primarily i = 1:50 to i = 1:90), whereby the inner and outer ring disks are rotated angularly synchronously. The rolling element tracks, in particular ball tracks, of the disks and the bearing block are designed in such a way that, starting from the neutral position, when the actuating disk is rotated to the left, only the rolling elements, preferably balls, of one ball track are rolled onto the corresponding ramp, causing the corresponding disk to perform a stroke. The other balls run in/on a ramp-free section of the corresponding track without a stroke. By turning back towards the neutral position, the brake is opened again. By turning to the right from the neutral position, the other brake is activated or closed, and turning back towards the neutral position opens it again. This is possible because with torque vectoring, either the left or the right wheel should rotate faster. The brakes can be controlled hydraulically or electromagnetically in alternative designs.

Further features of the invention can be derived from the claims, the figures and the description of the figures. The features and combinations of features mentioned above in the description as well as the features and combinations of features shown below in the description of the figures and/or in the figures alone can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the invention.

• 1 eine geschnittene Ansicht eines Teils einer Torque-Vectoring-Getriebeeinheit mit einem Betätigungssystem zum Betätigen zweier Torque-Vectoring-Schaltelemente,
• 2 eine getriebetopologische Ansicht einer die Torque-Vectoring-Getriebeeinheit aufweisenden Antriebsachse eines Kraftfahrzeugs bei
  1. a) Geradeausfahrt,
  2. b) bei erhöhter Drehmomentzustellung zum ersten Rad der Antriebsachse,
  3. c) bei erhöhter Drehmomentzustellung zum zweiten Rad der Antriebsachse,
• 3 eine schematische und geschnittene Ansicht des Betätigungssystems in Neutralstellung und nachdem dessen Betätigungsscheibe ausgehend von der Neutralstellung in eine erste Drehrichtung gedreht wurde,
• 4 eine schematische und geschnittene Ansicht des Betätigungssystems in Neutralstellung und nachdem dessen Betätigungsscheibe ausgehend von der Neutralstellung in eine entgegengesetzte, zweite Drehrichtung gedreht wurde, und
• 5 eine Prinzipdarstellung einer Mechanik des Betätigungssystems, dabei
• 5a eine Scheibe, Kugeln und einen Lagerblock des Betätigungssystems,
• 5b die aus den vorgenannten Bauteilen zusammengesetzte Mechanik zum Betätigen der Scheibe des in Neutralstellung angeordneten Betätigungssystems,
• 5c die Mechanik des Betätigungssystems, nachdem dessen Betätigungsscheibe ausgehend von der Neutralstellung in die erste Drehrichtung gedreht wurde,
• 5d die Mechanik des Betätigungssystems, nachdem dessen Betätigungsscheibe ausgehend von der Neutralstellung in die zweite Drehrichtung gedreht wurde.

The drawing shows in:

• 1 a sectional view of a part of a torque vectoring transmission unit with an actuation system for actuating two torque vectoring switching elements,
• 2 a transmission topological view of a drive axle of a motor vehicle having the torque vectoring transmission unit at
  1. a) Driving straight ahead,
  2. b) with increased torque delivery to the first wheel of the drive axle,
  3. c) with increased torque delivery to the second wheel of the drive axle,
• 3 a schematic and sectional view of the actuating system in the neutral position and after its actuating disc has been rotated in a first direction of rotation starting from the neutral position,
• 4 a schematic and sectional view of the actuating system in the neutral position and after its actuating disc has been rotated from the neutral position in an opposite, second direction of rotation, and
• 5 a schematic diagram of a mechanism of the actuation system,
• 5a a disc, balls and a bearing block of the actuation system,
• 5b the mechanism composed of the aforementioned components for operating the disc of the operating system arranged in the neutral position,
• 5c the mechanics of the actuating system after its actuating disc has been rotated from the neutral position in the first direction of rotation,
• 5d the mechanics of the actuating system after its actuating disc has been rotated from the neutral position into the second direction of rotation.

In the following, a joint description is given of an actuation system 1, a torque vectoring transmission unit 2 and a motor vehicle 38. In the figures, identical and functionally identical elements are provided with the same reference numerals.

1 shows a sectional view of a part of the torque vectoring transmission unit 2, which is referred to below as transmission unit 2. The transmission components of the transmission unit are also shown in the transmission topological views of 2 The transmission unit 2 has two torque vectoring switching elements 3, 4 (hereinafter referred to as switching elements 3, 4) and the actuation system 1 for actuating the switching elements 3, 4. According to the present example, and as shown in 1 As shown, the transmission unit 2 has three planetary gears 5, 6, 7, namely a primary differential 5, a secondary differential 6 and a tertiary differential 7. In the transmission unit 2, the switching elements 3, 4 are designed as a respective brake 3, 4, wherein the brake bearing the reference number 3 is referred to as the secondary brake 3 and the brake bearing the reference number 4 is referred to as the tertiary brake 4. The actuating system 1 has an actuating disk 8, which has an outer ring disk 9 and an inner disk 10 - here in the example designed as an inner ring disk 10 - wherein one of the disks 9, 10 cooperates with one of the brakes 3, 4 to actuate it, and the other of the disks 9, 10 cooperates with the other of the brakes 3, 4 to actuate it. In 1 it can be seen that the disks 9, 10 have a respective tappet 11, 12, whereby the inner ring disk 10 is in contact with the secondary brake 3 by means of the tappet 11, whereas the outer ring disk 9 is in contact with the tertiary brake 4 by means of its tappet 12. As will be explained in more detail below, the associated brake 3, 4 is axially loaded or unloaded, i.e. closed or opened, by moving the corresponding disk 9, 10 axially (along a main transmission axis 13) and consequently the corresponding tappet 11, 12.

The primary differential 5 is a planetary plus gear in Ravigneaux design, whose primary ring gear 14 forms a transmission drive element of the transmission unit 2, which means that when the transmission unit 2 is in operation by means of an electric drive machine 15 (see 2 ) torque and speed are introduced into the gear unit 2 via the primary ring gear 14. For this purpose, the primary ring gear 14 has an external gear 16 which meshes with a drive gear 17. As in 2 As can also be seen, in the present example a two-stage input transmission 19 is formed between a rotor shaft 18 of the drive machine 15 and the primary ring gear 14. A primary planet carrier 20 of the primary differential 5 is connected in a rotationally fixed manner to a first transmission output shaft 21 of the transmission unit 2, with a first primary sun gear 22 of the primary differential 5 being connected in a rotationally fixed manner to a second transmission output shaft 23 of the transmission unit 2. In addition, the primary differential 5 has a second primary sun gear 24, with a first primary planet gear 25 and a second primary planet gear 26 being mounted on the primary planet carrier 20. The first primary planet gear 25 meshes with both the first primary sun gear 22 and the second primary planet gear 26; there is no tooth engagement between the first primary planet gear 25 and the primary ring gear 14. The second primary planetary gear 26, which meshes with the first primary planetary gear 25, meshes with the second primary sun gear 24 and with the primary ring gear 14. The second primary sun gear 24 is connected in a rotationally fixed manner to a secondary ring gear 27 of the secondary differential 6, wherein a secondary sun gear 28 of the secondary differential 6 can be braked by means of the secondary brake 3, which is rotationally fixedly mounted on a transmission housing 29 of the transmission unit 2. A secondary planetary gear 31 is mounted on a secondary planetary carrier 30 of the secondary differential 6, which meshes on the one hand with the secondary ring gear 27 and on the other hand with the secondary sun gear 28. The secondary planetary carrier 30 is connected on the one hand to the second transmission output shaft 23 and on the other hand to a tertiary ring gear 32 of the tertiary differential 7. A tertiary sun gear 33 of the tertiary differential 7 can be braked by means of the tertiary brake 4, which is mounted in a rotationally fixed manner on the transmission housing 29. The tertiary differential 7 also has a tertiary planet gear 34, which meshes with the tertiary sun gear 33 and with the tertiary ring gear 32 and is mounted on a tertiary planet carrier 35 of the tertiary differential 7. The tertiary planet carrier 35 is connected in a rotationally fixed manner to the secondary ring gear 27.

Because the secondary brake 3 is coupled in this example to the outer ring disk 9 of the actuation system 1, the secondary brake 3 can be actuated by means of an axial disengagement of the outer ring disk 9 from a neutral position of the actuation system 1. Accordingly, the tertiary brake 4 can be actuated by means of an axial disengagement of the inner ring disk 10 from the neutral position. In the neutral position, the disks 9, 10 are arranged in a respective starting position and axially abut a bearing block 36 of the actuation system 1.

2 shows a transmission topology view of a drive axle 37 of the motor vehicle 38 having the transmission unit 2. Wheels or tire-rim combinations 39, 40 are each connected in a rotationally fixed manner to one of the transmission output shafts 21, 23. In a), straight-ahead travel is shown, whereby - since both brakes 3, 4 are not actuated - the torque (arrows M1, M2) provided by the drive machine 15 (only shown in a)) arrives in equal parts at the first (for example left) wheel 39 and the second (for example right) wheel 40. Torque vectoring, i.e. active torque delivery to the first wheel 39, is shown in b). For this purpose, the secondary brake 3 is actuated by means of the actuation system 1, whereby the secondary sun gear 28 on the transmission housing 29 is braked. A higher torque M1 is thus delivered to the first wheel 39, whereas a lower torque M2 is provided to the second wheel 40. In c), a torque vectoring to the second wheel 40 is shown, whereby the tertiary brake 4 is actuated by means of the actuation system 1, so that the tertiary sun gear 33 on the transmission housing 29 is braked. A higher torque M2 is thus delivered to the second wheel 40, whereas a lower torque M1 is provided to the first wheel 39. As a result, a right-hand yaw moment (around a vertical axis of the motor vehicle 38; perpendicular to the plane of the illustration of the 2 ) can be applied if the secondary brake 3 is used to brake more strongly than the tertiary brake 4. A left-turning yaw moment is generated if the tertiary brake 4 is used to brake more strongly than the secondary brake 3. In addition, if one of the wheels 39, 40 lacks traction, it can be prevented that the other wheel 40, 39 is provided with less torque in accordance with the lack of traction.

With the help of 3 and 4 A functional principle of the actuation system 1 is explained in more detail. In 3 and 4 The bearing block 36, the outer ring disk 9 and the inner ring disk 10 as well as rolling elements - here designed as balls 41 - of the actuating system 1 can be clearly seen. In the left half of the picture the 3 and the 4 The actuating system 1 is shown arranged in the neutral position, in which the discs 9, 10 are arranged axially along a axis aligned with the main transmission axis 13 (cf. 1 ) are arranged abutting the bearing block 36 on a longitudinal center axis 42 of the actuation system 1. The outer ring disk 9 has an outer disk rolling element track 43, whereas the inner ring disk 10 has an inner disk rolling element track 44. The bearing block 36 has an outer bearing block rolling element track 45 axially opposite the outer disk rolling element track 43 with the same radius and an inner bearing block rolling element track 46 axially opposite the inner disk rolling element track 44 with the same radius. One of the rolling elements, that is to say one of the balls 41 here, is inserted into the outer rolling element tracks 43, 45, and another of the balls 41 is inserted into the inner rolling element tracks 44, 46. In particular, the balls 41 are held in place by means of a cage 47 (see 1 ). The actuating disk 8 has a disk connection device 48, by means of which the outer ring disk 9 and the inner ring disk 10 are mounted on one another in a rotationally fixed and axially displaceable manner with respect to the longitudinal center axis 42. For this purpose, an external rotary connection structure 49 is arranged on an outer peripheral surface of the inner ring disk 10, which engages in a rotationally fixed and axially movable manner in an inner rotary connection structure 50 arranged on an inner peripheral surface of the outer ring disk 9 and corresponding to the external rotary connection structure 49. In this example, the external rotary connection structure 49 has an external wedge structure, and the internal rotary connection structure 50 has an internal wedge structure. The external wedge structure engages in the inner wedge structure in a rotationally fixed and axially movable manner, whereby a spline is formed between the outer ring disk 9 and the inner ring disk 10.

According to the present example, the outer disk rolling element track 43 has a first outer ramp 51, wherein the outer bearing block rolling element track 45 has a second outer ramp 52. Furthermore, the inner disk rolling element track 44 has a first inner ramp 53, wherein the inner bearing block rolling element track 46 has a second inner ramp 54. The outer ramps 51, 52 differ from one another in that the outer ramps 51, 52 are oriented opposite to one another. Furthermore, the inner ramps 53, 54 are oriented opposite to one another. In addition, the ramps 51, 53 are oriented opposite to the ramps 52, 54. It follows that by rotating the actuating disk 8 in relation to the bearing block 36, the outer ring disk 9 and the inner ring disk 10 are moved axially in different ways along the longitudinal center axis 42.

In the present case, the ramps 51, 52, 53, 54 and the rolling element tracks 43, 44, 45, 46 are designed and arranged in such a way that - starting from the neutral position - the outer ring disk 9 is moved axially away from the bearing block 36 when the actuating disk 8 is rotated in a first direction of rotation 55 in relation to the bearing block 36, as shown in the left half of the figure of the 3 is shown. The inner ring disk 10 is not moved axially when the outer ring disk 9 is moved, i.e. it is not disengaged from its initial position. Since the outer ring disk 9 interacts with the secondary brake 3, the secondary brake 3 is actuated. by rotating the actuating disk 8 of the actuating system 1 in the first direction of rotation 55 in relation to the bearing block 36. The tertiary brake 4, which interacts with the inner ring disk 10, remains unactuated. After rotating the actuating disk 8, the 3 As shown, the inner ring disk 10 is still arranged in its initial position despite radial rotation about the longitudinal center axis 42, whereas the outer ring disk 9 is disengaged from its initial position into an actuating position.

On the other hand, starting from the neutral position, the inner ring disk 10 is moved axially away from the bearing block 36 when the actuating disk 8 is rotated in relation to the bearing block 36 in a second direction of rotation 56 opposite to the first direction of rotation 55, as shown in the left half of the figure of the 4 is shown. The outer ring disk 9 is not moved axially when the inner ring disk 10 is moved, i.e. it is not disengaged from its initial position. Since the inner ring disk 10 interacts with the tertiary brake 4, the tertiary brake 4 is actuated by rotating the actuating disk 8 of the actuating system 1 in the second direction of rotation 56 in relation to the bearing block 36. The secondary brake 3 interacting with the outer ring disk 9 remains unactuated. After rotating the actuating disk 8, as shown in the right half of the figure, the 4 As shown, the outer ring disk 9 is still arranged in its initial position despite radial rotation about the longitudinal center axis 42, whereas the inner ring disk 10 is disengaged from its initial position into an actuating position.

The actuation system 1 has exactly one actuator (not shown) for rotating the actuation disk 8, which is coupled to the actuation disk 8 in this example and is designed to rotate the actuation disk 8 in relation to the bearing block 36 about the longitudinal center axis 42. For this purpose, the outer ring disk 9 has an external gear rim 57, with a gear 58 (see 1 ) of the actuator meshes with the external gear rim 57. The gear 58 of the actuator is designed as a worm gear. A further actuator is not provided for actuating the brakes 3, 4.

The brakes 3, 4 can therefore each be actuated separately from one another - starting from the neutral position of the actuating system 1 - depending on in which of the rotational directions 55, 56 the actuating disk 8 is rotated by means of only one single actuator.

5 shows a schematic diagram of the mechanism of the actuation system 1, in which 5a the inner ring disk 10, the balls 41 and the bearing block 36 of the actuation system 1 are shown. The inner ring disk 10, the balls 41 and the bearing block 36 are, as shown in 5b shown, assembled. The bearing block 36 and the inner ring disk 10 lie along the longitudinal center axis 42 (not visible; perpendicular to the image plane of the 5 ) abut each other. The inner ring disc 10 is therefore arranged in its initial position. In 5c the mechanics are shown after the inner ring disk 10 (by turning the actuating disk 8) has been rotated in the first direction of rotation 55 in relation to the bearing block 36. It can be seen that during the rotation the balls 41 are rolled in wide track sections 59 of the bearing block rolling element tracks 45, 46 and at the same time in wide track sections 60 of the disc rolling element tracks 43, 44. This means that no axial stroke is created for the inner disk 10, so that the tertiary brake 4 is not actuated. The mechanics are in 5d shown after the inner ring disk 10 has been rotated in the second direction of rotation 56 in relation to the bearing block 36. It can be seen that during this rotation the balls 41 are rolled from the wide track sections 59, 60 via a respective one of the ramps 51, 52, 53, 54 into narrow track sections 61 of the bearing block rolling element tracks 45, 46 and at the same time into narrow track sections 62 of the disc rolling element tracks 43, 44. This creates an axial stroke for the inner disk 10 so that the tertiary brake 4 is actuated. This mechanism is attached analogously to the outer ring disk 9.

List of reference symbols

1

Actuation system

2

Gear unit

3

Torque vectoring switching element/secondary brake

4

Torque vectoring switching element/tertiary brake

5

Primary differential

6

Secondary differential

7

Tertiary differential

8th

Actuating disc

9

Outer ring disc

10

Inner disc/inner ring disc

11

Pestle

12

Pestle

13

Transmission main axis

14

Primary ring gear

15

electric drive machine

16

External gear ring

17

Drive gear

18

Rotor shaft

19

Input translation

20

Primary planet carrier

21

first transmission output shaft

22

first primary sun gear

23

second transmission output shaft

24

second primary sun gear

25

first primary planetary gear

26

second primary planetary gear

27

Secondary ring gear

28

Secondary sun gear

29

Gearbox housing

30

Secondary planet carrier

31

Secondary planetary gear

32

Tertiary ring gear

33

Tertiary sun wheel

34

Tertiary planetary gear

35

Tertiary planet carrier

36

Bearing block

37

Drive axle

38

Motor vehicle

39

first bike

40

second wheel

41

Bullet

42

Longitudinal center axis

43

outer disc rolling element track

44

inner disc rolling element track

45

outer bearing block rolling element track

46

inner bearing block rolling element track

47

Cage

48

Disc connection device

49

External slewing ring structure

50

Internal slewing ring structure

51

first outer ramp

52

second outer ramp

53

first inner ramp

54

second inner ramp

55

first direction of rotation

56

second direction of rotation

57

External gear ring

58

Gear/worm wheel

59

wide track share

60

wide track share

61

narrow track portion

62

narrow track portion

M1

Torque

M2

Torque

Claims (6)

Torque vectoring transmission unit (2) for a motor vehicle (38), which has an actuation system (1) by means of which a secondary brake (3) and a tertiary brake (4) of the transmission unit (2) can be actuated, wherein the actuation system (1) has: - an actuation disk (8), comprising: - an outer ring disk (9) mechanically coupled to the secondary brake (3) with an outer disk rolling element track (43), - an inner disk (10) mechanically coupled separately to the tertiary brake (4) with an inner disk rolling element track (44), and - a disk connection device (48), by means of which the outer ring disk (9) and the inner disk (10) are mounted on one another in a rotationally fixed manner and axially displaceable relative to one another in relation to a longitudinal center axis (42) of the actuation system (1), - a bearing block (36) with an outer disk rolling element track (43) axially opposite the outer disk rolling element track (43) with the same radius. Bearing block rolling element track (45) and an inner bearing block rolling element track (46) axially opposite the inner disc rolling element track (44) with the same radius, - rolling elements (41), one of which is inserted into the outer rolling element tracks (43, 45) and another into the inner rolling element tracks (44, 46), one of the outer rolling element tracks (43, 45) having an outer ramp (51, 52) and one of the inner rolling element tracks (44, 46) having an inner ramp (53, 54), the outer ramp (51, 52) and the inner ramp (53, 54) differing in a ramp configuration, so that by rotating the actuating disk (8) in relation to the bearing block (36), the outer ring disk (9) and the inner disk (10) are moved axially differently along the longitudinal center axis (42), the ramps (51, 52, 53, 54) and the rolling element tracks (43, 44, 45, 46) are designed and arranged such that, starting from a neutral position in which the discs (9, 10) are axially Bearing block (36), - when the actuating disk (8) is rotated in a first direction of rotation (55) with respect to the bearing block (36), the outer disk (9) is moved axially away from the bearing block (36), the inner disk (10) remaining axially stationary as the outer ring disk (9) moves, - when the actuating disk (8) is rotated in a second direction of rotation (56) opposite to the first direction of rotation (55), the inner disk (10) is moved axially away from the bearing block (36), the outer ring disk (9) remaining axially stationary as the inner disk (10) moves, the torque vectoring transmission unit (2) further comprising a primary differential (5), a secondary differential (6) and a tertiary differential (7), each of which is designed as a planetary gear, wherein: - by a primary ring gear (14) of the Primary differential (5) a transmission drive element is formed, - a primary planet carrier (20) of the primary differential (5) is connected to a first transmission output shaft (21), - a first primary sun gear (22) of the primary differential (5) is connected to a second transmission output shaft (23), - a second primary sun gear (26) of the primary differential (5) is connected to a secondary ring gear (27) of the secondary differential (6), - a secondary sun gear (28) of the secondary differential (6) can be braked by means of the secondary brake (3), which is mounted in a rotationally fixed manner on a transmission housing (29), - a secondary planet carrier (30) of the secondary differential (6) is connected on the one hand to the second transmission output shaft (23) and on the other hand to a tertiary ring gear (32) of the tertiary differential (7), - a tertiary sun gear (33) of the Tertiary differential (7) can be braked by means of the tertiary brake (4) which is mounted on the transmission housing (29) in a rotationally fixed manner, - a tertiary planet carrier (35) of the tertiary differential (7) is connected to the secondary ring gear (27), wherein starting from the neutral position of the actuating system (1), the secondary brake (3) or the tertiary brake (4) is actuated depending on the direction of rotation (55, 56) of the actuating disk (8). Torque vectoring gear unit (2) according to Claim 1 , characterized in that the actuating system (1) has exactly one actuator which is coupled to the bearing block (36) or to the actuating disk (8) and is adapted to rotate the actuating disk (8) in relation to the bearing block (36) about the longitudinal center axis (42). Torque vectoring gear unit (2) according to Claim 2 , characterized in that the bearing block (36) or the actuating disk (8) has an external gear ring (57), and a gear (58) of the actuator meshes with the external gear ring (57). Torque vectoring gear unit (2) according to Claim 3 , characterized in that the gear (58) of the actuator is designed as a worm wheel. Torque vectoring gear unit (2) according to one of the preceding claims, characterized in that an external rotary connection structure (49) is arranged on an outer peripheral surface of the inner disk (10), which engages in a rotationally fixed and axially movable manner in an internal rotary connection structure (50) arranged on an inner peripheral surface of the outer ring disk (9) and corresponding to the external rotary connection structure (49). Motor vehicle (38) or drive axle (37) for a motor vehicle (38), comprising a torque vectoring transmission unit (2) designed according to one of the preceding claims.

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