Transmission and drive system for a motor vehicle

Abstract

Transmission (1) for a motor vehicle (100), comprising • a first planetary gear set (P1), a second planetary gear set (P2) and a third planetary gear set (P3), wherein each planetary gear set (P1, P2, P3) has a first element (E11, E21, E31), a second element (E12, E22, E32) and a third element (E13, E23, E33), • exactly one drive shaft (WAn) for connecting the transmission (1) to a drive motor (2) of the motor vehicle (100), • a first output shaft (WAb1) and a second output shaft (WAb2) each for connecting the transmission (1) to a wheel (R1, R2) of the motor vehicle (100), • a first coupling shaft (W1) and a second coupling shaft (W2) each for the rotationally fixed connection of two elements of two planetary gear sets (P1, P2, P3), • wherein one of the elements (E11, E21, E31) of the first planetary gear set (P1) is non-rotatably connected to the first output shaft (WAb1), wherein another of the elements (E11, E21, E31) of the first planetary gear set (P1) is non-rotatably connected to the first coupling shaft (W1), wherein another of the elements (E11, E21, E31) of the first planetary gear set (P1) is non-rotatably connected to the second coupling shaft (W2), • wherein one of the elements (E12, E22, E32) of the second planetary gear set (P2) is non-rotatably connected to the first coupling shaft (W1), wherein another of the elements (E12, E22, E32) of the second planetary gear set (P2) is non-rotatably connected to a stationary component, wherein a further element (E12, E22, E32) of the second planetary gear set (P2) is non-rotatably connected to the second output shaft (WAb2), • wherein one of the elements (E13, E23, E33) of the third planetary gear set (P3) is non-rotatably connected to the second coupling shaft (W2), wherein another of the elements (E13, E23, E33) of the third planetary gear set (P3) is non-rotatably connected to the input shaft (WAn), wherein another of the elements (E13, E23, E33) of the third planetary gear set (P3) is non-rotatably connected to the second output shaft (WAb2).

Description

[0001] The invention relates to a transmission for a motor vehicle comprising three planetary gear sets and five shafts, wherein one of the five shafts is designed as an input shaft and is configured to be drivingly connected to a prime mover, and wherein two of the five shafts are designed as output shafts and are configured to be drivingly connected to a respective wheel of the motor vehicle. Furthermore, the invention relates to a drive device having such a transmission and a motor vehicle having such a drive device.

[0002] For example, DE 10 2013 215 877 A1 discloses an epicyclic gear system for splitting the drive power applied to a power input to a first and a second power output, in conjunction with a reduction of the output speed to a speed level below the drive speed at the power input. The epicyclic gear system comprises a first gear stage having a first sun gear, a first planetary gear set, a first planetary carrier, and a first ring gear; a second gear stage having a second sun gear, a second planetary gear set, a second planetary carrier, and a second ring gear; and a third planetary gear stage having a third sun gear, a third planetary gear set, and a third planetary carrier.The first sun gear is configured as the power input, the first planet carrier is rotationally coupled to the second sun gear, the second planet carrier is stationary, the first ring gear is coupled to the third sun gear, the first power output occurs via the third gear stage, and the second power output occurs via the second ring gear of the second gear stage.

[0003] The object of the present invention is to create an alternative transmission that, in particular, has improved power density and improved efficiency. The transmission is intended to generate two approximately equal output torques from a single input torque, which are greater than the input torque. Thus, the transmission is intended to implement both a transmission function, i.e., a torque conversion, and a differential function. These objects are achieved by a transmission having the features of patent claim 1.

[0004] Advantageous embodiments are the subject of the dependent claims, the following description and the figures.

[0005] A transmission according to the invention for a motor vehicle comprises a first planetary gear set, a second planetary gear set and a third planetary gear set, each planetary gear set having a first element, a second element and a third element, five shafts, namely an input shaft for connecting the transmission to a drive engine of the motor vehicle, a first output shaft and a second output shaft each for connecting the transmission to a wheel of the motor vehicle, a first coupling shaft and a second coupling shaft each for the rotationally fixed connection of two elements of two planetary gear sets, • wherein one of the elements of the first planetary gear set is connected in a rotationally fixed manner to the first output shaft, wherein another of the elements of the first planetary gear set is connected in a rotationally fixed manner to the first coupling shaft, wherein another of the elements of the first planetary gear set is connected in a rotationally fixed manner to the second coupling shaft, • wherein one of the elements of the second planetary gear set is connected in a rotationally fixed manner to the first coupling shaft, wherein another of the elements of the second planetary gear set is connected in a rotationally fixed manner to a stationary component, wherein another of the elements of the second planetary gear set is connected in a rotationally fixed manner to the second output shaft, • wherein one of the elements of the third planetary gear set is connected in a rotationally fixed manner to the second coupling shaft, wherein another of the elements of the third planetary gear set is connected in a rotationally fixed manner to the input shaft, wherein another of the elements of the third planetary gear set is connected in a rotationally fixed manner to the second output shaft.

[0006] A "connection" of a device or element to the transmission means that the transmission, in particular the corresponding shaft of the transmission, is either directly connected to the device or element, for example in a rotationally fixed manner, or indirectly connected, for example via at least one further component, in particular via at least one further shaft or gear. If two shafts are connected to one another in a rotationally fixed manner, they rotate together in one direction of rotation at one rotational speed. In particular, the connection can also be made via a switching element, which enables a drive-effective coupling and decoupling of the device or element with the corresponding shaft of the transmission.

[0007] A "shaft" is not exclusively understood to mean, for example, a cylindrical, rotatably mounted transmission element for transmitting torque, but rather also general connecting elements that connect individual components or elements together, in particular connecting elements that connect several elements together in a rotationally fixed manner. Two shafts connected in a rotationally fixed manner can be formed as a single piece.

[0008] A "stationary component" is a non-rotating component of the transmission. For example, the stationary component is designed as a housing or housing section of the transmission. Alternatively, the stationary component can be designed as a shaft fixed to the housing.

[0009] The first planetary gear set is therefore connected to the first output shaft, as well as to the second planetary gear set via the first coupling shaft and to the third planetary gear set via the second coupling shaft. Furthermore, the second planetary gear set is connected to the housing in a rotationally fixed manner and to the third planetary gear set via the second output shaft. The third planetary gear set is moreover connected or connectable to the prime mover at least directly or indirectly via the input shaft. The first planetary gear set is or connectable to a first wheel of the motor vehicle at least directly or indirectly via the first output shaft. Furthermore, the second and third planetary gear sets are or connectable to a second wheel of the motor vehicle at least directly or indirectly via the second output shaft.

[0010] For example, the drive machine is designed as an electric machine that can be operated as a drive motor to drive the vehicle and as a generator to recuperate electrical energy. For this purpose, the electric machine is electrically connected to an electrical energy storage device. The electric machine comprises a rotor and a stator, wherein the rotor is connected in a rotationally fixed manner to a rotor shaft. The rotor shaft of the electric machine is connected at least directly or indirectly to the drive shaft. For example, the rotor shaft of the electric machine is connected to the drive shaft via at least one further shaft, via a plurality of gears and / or via a traction means. The electric machine can be arranged on a common axis of rotation with the transmission and thus be designed coaxially to the drive shaft, wherein the rotor shaft is then preferably connected in a rotationally fixed manner to the drive shaft.Alternatively, the electric motor can be designed to be axially parallel to the drive shaft, in which case the rotor shaft is indirectly connected to the drive shaft. Alternatively, the drive motor can be designed as an internal combustion engine with a crankshaft.

[0011] According to a preferred embodiment, the first element of the first planetary gear set is rotationally fixedly connected to the second coupling shaft, wherein the second element of the first planetary gear set is rotationally fixedly connected to the first coupling shaft, wherein the third element of the first planetary gear set is rotationally fixedly connected to the first output shaft, wherein the first element of the second planetary gear set is rotationally fixedly connected to the second output shaft, wherein the second element of the second planetary gear set is rotationally fixedly connected to a stationary component, wherein the third element of the second planetary gear set is rotationally fixedly connected to the first coupling shaft, wherein the first element of the third planetary gear set is rotationally fixedly connected to the input shaft, wherein the second element of the third planetary gear set is rotationally fixedly connected to the second output shaft, wherein the third element of the third planetary gear set is rotationally fixedly connected to the second coupling shaft.Preferably, the third planetary gear set is arranged axially between the second planetary gear set and the first planetary gear set. For this purpose, reference is made to the embodiment according to . Fig. 3.

[0012] According to a preferred embodiment, the first element of the first planetary gear set is rotationally fixedly connected to the second coupling shaft, wherein the second element of the first planetary gear set is rotationally fixedly connected to the first output shaft, wherein the third element of the first planetary gear set is rotationally fixedly connected to the first coupling shaft, wherein the first element of the second planetary gear set is rotationally fixedly connected to the first coupling shaft, wherein the second element of the second planetary gear set is rotationally fixedly connected to a stationary component, wherein the third element of the second planetary gear set is rotationally fixedly connected to the second output shaft, wherein the first element of the third planetary gear set is rotationally fixedly connected to the input shaft, wherein the second element of the third planetary gear set is rotationally fixedly connected to the second output shaft, wherein the third element of the third planetary gear set is rotationally fixedly connected to the second coupling shaft.Preferably, the first planetary gear set is arranged axially between the second planetary gear set and the third planetary gear set. For this purpose, reference is made to the embodiment according to . Fig. 4.

[0013] According to a preferred embodiment, one of the two coupling shafts or one of the two output shafts is formed in one piece with the elements of the respective planetary gear set connected thereto.

[0014] According to a preferred embodiment, at least one of the planetary gear sets is designed as a negative planetary gear set, with the first element of the respective planetary gear set being designed as a sun gear, the second element of the respective planetary gear set being designed as a planet carrier, and the third element of the respective planetary gear set being designed as a ring gear. Several planetary gears are rotatably mounted on the planet carrier and mesh with the sun gear and the ring gear.

[0015] Alternatively, at least one of the planetary gear sets can be designed as a minus stepped planetary gear set, in which case the planet carrier rotatably supports several stepped planetary gears. Each stepped planetary gear has two gears that are connected to one another in a rotationally fixed manner. In other words, each stepped planetary gear has two toothed sections that are connected to one another in a rotationally fixed manner and have different diameters. One of the two toothed sections meshes with the sun gear, and the other of the two toothed sections meshes with the ring gear. If the first element of the minus stepped planetary gear set is a sun gear, then the third element of the minus stepped planetary gear set is designed as a ring gear. If the first element of the minus stepped planetary gear set is a ring gear, then the third element of the minus stepped planetary gear set is designed as a sun gear. In both cases, the second element of the minus stepped planetary gear set is designed as a planet carrier.

[0016] According to a preferred embodiment, at least one of the planetary gear sets is designed as a positive planetary gear set, wherein the first element of the respective planetary gear set is designed as a sun gear, the second element of the respective planetary gear set is designed as a ring gear, and the third element of the respective planetary gear set is designed as a planet carrier. In a positive planetary gear set, the planet carrier guides at least one pair of planetary gears, in which one planetary gear meshes with the inner sun gear and the other planetary gear meshes with the surrounding ring gear, and the planetary gears mesh with one another.

[0017] Alternatively, at least one of the planetary gear sets can be designed as a plus-stepped planetary gear set with two sun gears or as a plus-stepped planetary gear set with two ring gears. In a plus-stepped planetary gear set with two sun gears, the first and second elements of the plus-stepped planetary gear set are each designed as sun gears, with the third element of the plus-stepped planetary gear set being designed as a planet carrier. In a plus-stepped planetary gear set with two ring gears, the first and second elements of the plus-stepped planetary gear set are each designed as ring gears, with the third element of the plus-stepped planetary gear set being designed as a planet carrier.

[0018] According to a preferred embodiment, a constant gear ratio is arranged upstream of the drive shaft in the power flow. The gear ratio is therefore designed as a pre-transmission. The constant gear ratio preferably comprises a fourth planetary gear set with a first element, a second element, and a third element. Alternatively or additionally, the constant gear ratio comprises a spur gear stage with a first gear and a second gear. If the gear ratio is designed as a planetary gear set, one of the elements of the planetary gear set is fixed to the housing, another of the elements is or can be connected at least directly or indirectly to a shaft of the drive machine, and another of the elements is connected to the drive shaft in a rotationally fixed manner.If the gear ratio is designed as a spur gear stage, the drive motor is arranged axially parallel to the transmission and thus also to the input shaft and the two output shafts. Higher gear ratios can be achieved in the transmission by using a gear ratio stage.

[0019] According to a preferred embodiment, a first shifting element for shifting a first gear and a second shifting element for shifting a second gear are arranged in the power flow upstream of the drive shaft. A "shifting element" is understood to be a switchable device that has at least one open and one closed state, wherein in the open state two shafts connected to it can rotate freely, and wherein in the closed state the two shafts are connected to one another in a rotationally fixed manner. For example, the first and second shifting elements, together with a planetary gear set, form a 2-speed assembly that is connected upstream of the three planetary gear sets of the transmission. The upstream planetary gear set has, for example, the elements sun gear, ring gear, and planet carrier. The upstream planetary gear set is blocked via the first shifting element.In other words, two elements of the upstream planetary gear set, for example the sun gear and the ring gear, are connected in a rotationally fixed manner so that the upstream planetary gear set rotates as a block and has a gear ratio of 1. One of the elements of the upstream planetary gear set, for example the sun gear, is connected in a rotationally fixed manner to the housing via the second switching element, so that a different gear ratio is set. The second switching element is therefore designed as a brake. In this context, a "brake" is understood to be a switchable device which, when closed, connects a shaft of the upstream planetary gear set to a housing in a rotationally fixed manner so that this shaft is then fixed in a stationary manner and thus prevented from rotating. When the switching element is open, the shaft is decoupled from the housing, allowing this shaft to rotate freely. Each switching element can be switched by a respective actuator.

[0020] According to a preferred embodiment, a shifting element for generating a locking effect is arranged between the two output shafts. This shifting element can be designed as a frictional or positive-locking shifting element. For example, a positive-locking shifting element is designed as a dog clutch. A positive-locking shifting element can increase the efficiency of the transmission due to reduced drag losses. In particular, positive-locking shifting elements are more compact and have an optimized efficiency and have a cost advantage over frictional shifting elements. However, slip operation, i.e. a limited locking effect under differential speed, is not possible with positive-locking shifting elements. For example, a frictional shifting element comprises several plates or at least one conical friction surface.In the case of a friction-locking switching element, this can be actuated via an actuator or mechanically, particularly by utilizing axial forces from helical gears. An actuator can be fixed to the housing or mounted so that it rotates.

[0021] A drive device according to the invention comprises a drive motor and a transmission according to the invention. The drive motor is preferably designed as an electric motor. Alternatively, the drive motor is designed as an internal combustion engine. The drive motor can be arranged coaxially or axially parallel to the drive shaft of the transmission. The drive power of the drive motor is fed into the transmission via the drive shaft and distributed to the two output shafts, with each output shaft being drivingly connected to a respective drive wheel of a drive axle of the vehicle.

[0022] A vehicle according to the invention comprises a drive device according to the invention. In particular, the vehicle is designed as an electric vehicle and has an electric drive axle with the drive device according to the invention. The above definitions as well as statements regarding technical effects, advantages, and advantageous embodiments of the transmission according to the invention also apply mutatis mutandis to the drive device according to the invention and to the vehicle according to the invention.

[0023] Advantageous embodiments of the invention, which are explained below, are illustrated in the drawings, wherein like elements are provided with the same reference numerals. They show: Fig. 1 a highly abstracted schematic view of a motor vehicle with a drive device according to the invention; Fig. 2 a highly abstracted schematic diagram of the drive device according to the invention; Fig. 3 a highly abstracted schematic view of the drive device according to the invention according to a first embodiment; Fig. 4 a highly abstracted schematic view of a drive device according to the invention according to a second embodiment; Fig. 5 a highly abstracted schematic view of a drive device according to the invention according to a third embodiment; Fig. 6 a highly abstracted schematic view of a drive device according to the invention according to a fourth embodiment; Fig. 7 a highly abstracted schematic view of a drive device according to the invention according to a fifth embodiment; Fig. 8 shows a highly abstracted schematic view of a drive device according to the invention according to a sixth embodiment; Fig. 9 a highly abstracted schematic view of a drive device according to the invention according to a seventh embodiment; Fig. 10 a highly abstracted schematic view of a plus planetary gear set; Fig. 11 a highly abstracted schematic view of a minus-step planetary gear set; Fig. 12 a highly abstracted schematic view of a plus-stepped planetary gear set with two sun gears; and Fig. 13 a highly abstracted schematic view of a plus-stepped planetary gear set with two ring gears.

[0024] Fig. 1 shows a motor vehicle 100 with a first wheel axle 101 with two wheels R1, R2 and a second wheel axle 102 with two wheels R3, R4. In the present case, the first wheel axle 101 is designed as the rear drive axle of the motor vehicle 100 and is equipped with a drive device according to the invention, which has a single drive motor 2 designed as an electric machine and a transmission 1 designed as an epicyclic gear train. Thus, the motor vehicle 100 is designed as an electric vehicle. The drive device is arranged transversely to the vehicle's longitudinal direction and is drivingly connected to the wheels R1, R2 of the first wheel axle 101. In the present case, no further drive device is arranged on the second wheel axle 102, i.e., on the front axle of the vehicle 100, thereby saving costs, weight, and installation space. Alternatively, the drive device can also be arranged on the front axle of the motor vehicle 100 instead of on the rear axle.To implement an all-wheel drive system, a further drive device can be arranged on the second wheel axle 102 and can be drivingly connected to the wheels R3, R4 of this wheel axle 102.

[0025] Fig. 2 shows a schematic diagram of the drive device according to Fig. 1. The transmission 1 of the drive device comprises a first planetary gear set P1, a second planetary gear set P2 and a third planetary gear set P3, each graphically represented by a circle. Each planetary gear set P1, P2, P3 has a first element, a second element and a third element, each of which is indicated by three connection options on the respective planetary gear set P1, P2, P3. Furthermore, the transmission 1 comprises five shafts, namely an input shaft WAn for connecting the transmission 1 to the drive engine 2, a first output shaft WAb1 and a second output shaft Wab2, each for connecting the transmission 1 to a wheel of the motor vehicle, as well as a first coupling shaft W1 and a second coupling shaft W2.

[0026] One of the elements of the first planetary gear set P1 is rotationally fixed to the first output shaft WAb1. Another of the elements of the first planetary gear set P1 is rotationally fixed to the first coupling shaft W1. Another of the elements of the first planetary gear set P1 is rotationally fixed to the second coupling shaft W2.

[0027] One of the elements of the second planetary gear set P2 is rotationally fixed to the first coupling shaft W1. Thus, the first planetary gear set P1 is connected to the second planetary gear set P2 via the first coupling shaft W1. Another of the elements of the second planetary gear set P2 is rotationally fixed to a stationary component of the transmission 1, designed as a housing G. Another of the elements of the second planetary gear set P2 is rotationally fixed to the second output shaft WAb2.

[0028] One of the elements of the third planetary gear set P3 is rotationally fixed to the second coupling shaft W2. Thus, the first planetary gear set P1 is connected to the third planetary gear set P3 via the second coupling shaft W2. Another of the elements of the third planetary gear set P3 is rotationally fixed to the input shaft WAn. The third planetary gear set P3 is drive-effectively connected to the drive motor 2 via the input shaft WAn. In other words, at least one further shaft, gear, shifting element, or the like can be arranged in the power flow between the drive motor 2 and the input shaft WAn. Another of the elements of the third planetary gear set P3 is rotationally fixed to the second output shaft WAb2. Thus, the second planetary gear set P2 is connected to the third planetary gear set P3 via the second output shaft WAb2.

[0029] Fig. 3 schematically shows the drive device with the transmission 1 according to a first embodiment. The advantage of this first embodiment is the good efficiency and the wide gear ratio range of the transmission 1. The transmission 1 comprises the first planetary gear set P1, the second planetary gear set P2 and the third planetary gear set P3, wherein each of the three planetary gear sets P1, P2, P3 has a first element E11, E21, E31, a second element E12, E22, E32 and a third element E13, E23, E33. In the present case, the first element E11, E21, E31 of the respective planetary gear set P1, P2, P3 is designed as a sun gear, wherein the second element E12, E22, E32 of the respective planetary gear set P1, P2, P3 is designed as a planet carrier, wherein the third element E13, E23, E33 of the respective planetary gear set P1, P2, P3 is designed as a ring gear.Each planet carrier carries at least one planetary gear, which meshes with the sun gear and the ring gear of the respective planetary gear set P1, P2, P3. Thus, each of the three planetary gear sets P1, P2, P3 is designed as a conventional negative planetary gear set. Alternatively, at least one of the three planetary gear sets can be designed as a conventional positive planetary gear set, a negative stepped planetary gear set, a positive stepped planetary gear set with two sun gears, or a positive stepped planetary gear set with two ring gears.

[0030] The first element E11 of the first planetary gear set P1 is connected in a rotationally fixed manner to the second coupling shaft W2, wherein the second element E12 of the first planetary gear set P1 is connected in a rotationally fixed manner to the first coupling shaft W1, wherein the third element E13 of the first planetary gear set P1 is connected in a rotationally fixed manner to the first output shaft WAb1.

[0031] The first element E21 of the second planetary gear set P2 is connected in a rotationally fixed manner to the second output shaft WAb2, wherein the second element E22 of the second planetary gear set P2 is connected in a rotationally fixed manner to a stationary component designed as a housing G, wherein the third element E23 of the second planetary gear set P2 is connected in a rotationally fixed manner to the first coupling shaft W1.

[0032] The first element E31 of the third planetary gear set P3 is rotationally fixedly connected to the input shaft WAn, wherein the second element E32 of the third planetary gear set P3 is rotationally fixedly connected to the second output shaft WAb2, wherein the third element E33 of the third planetary gear set P3 is rotationally fixedly connected to the second coupling shaft W2. The input shaft WAn is presently connected to the drive motor 2. Alternatively, further elements, in particular shafts, gears, switching elements or other devices, can be arranged in the power flow between the drive motor 2 and the input shaft WAn. For example, the power flow between the drive motor 2 and the input shaft WAn can be interrupted by a switching element.

[0033] Thus, the first element E21 of the second planetary gear set P2 and the second element E32 of the third planetary gear set P3 are connected to one another in a rotationally fixed manner via the second output shaft WAb2. Furthermore, the first coupling shaft W1 connects the second element E12 of the first planetary gear set P1 in a rotationally fixed manner to the third element E23 of the second planetary gear set P2, while the second coupling shaft W2 connects the first element E11 of the first planetary gear set P1 in a rotationally fixed manner to the third element E33 of the third planetary gear set P3.

[0034] The third planetary gear set P3 is arranged axially between the second planetary gear set P2 and the first planetary gear set P1, with the second planetary gear set P2 axially adjacent to the drive machine 2. This gives the drive device a compact design. The input shaft WAn has the same direction of rotation as the two output shafts WAb1, WAb2. All three planetary gear sets P1, P2, P3 are arranged on a common axis of rotation R. The drive machine 2 is arranged coaxially to the axis of rotation R. The input shaft WAn is designed as a hollow shaft, with the second output shaft WAb2 extending axially through the input shaft WAn and the drive machine 2. The respective output shaft WAb1, WAb2 is connected in a rotationally fixed manner to a respective wheel of the motor vehicle.

[0035] Fig. 4 shows a second embodiment of the drive device according to the invention. The drive device according to Fig. 4 essentially corresponds to the drive device according to Fig. 3, whereby a difference between these two embodiments lies in the arrangement and connection of the planetary gear sets P1, P2, P3. The advantage of this second embodiment is the good efficiency and the wide gear ratio range of the transmission 1. The first planetary gear set P1 is arranged axially between the third planetary gear set P3 and the second planetary gear set P2, whereby the third planetary gear set P3 is axially adjacent to the drive machine 2. This gives the drive device a compact design. The input shaft WAn has a different direction of rotation than the two output shafts WAb1, WAb2. In the present case, the first element E11 of the first planetary gear set P1 is connected in a rotationally fixed manner to the second coupling shaft W2, whereby the second element E12 of the first planetary gear set P1 is connected in a rotationally fixed manner to the first output shaft WAb1, whereby the third element E13 of the first planetary gear set P1 is connected in a rotationally fixed manner to the first coupling shaft W1.The first element E21 of the second planetary gear set P2 is rotationally fixed to the first coupling shaft W1, wherein the second element E22 of the second planetary gear set P2 is rotationally fixed to a stationary component designed as a housing G, wherein the third element E23 of the second planetary gear set P2 is rotationally fixed to the second output shaft WAb2. Furthermore, the first element E31 of the third planetary gear set P3 is rotationally fixed to the input shaft WAn, wherein the second element E32 of the third planetary gear set P3 is rotationally fixed to the second output shaft WAb2, wherein the third element E33 of the third planetary gear set P3 is rotationally fixed to the second coupling shaft W2. Otherwise, the exemplary embodiment corresponds to . Fig. 4 the embodiment according to Fig. 3, to which reference is made.

[0036] Fig. 5 shows a third embodiment of the drive device according to the invention. The drive device according to Fig. 5 essentially corresponds to the drive device according to Fig. 3, wherein a difference between these two embodiments lies in the arrangement of a constant gear ratio in the power flow between the drive motor 2 and the drive shaft WAn. In the present case, this pre-transmission is designed as a fourth planetary gear set P4 and comprises a first element E41 designed as a sun gear, a second element E42 designed as a planet carrier, and a third element E43 designed as a ring gear. The first element E41 of the fourth planetary gear set P4 is connected in a rotationally fixed manner to the stationary component designed as a housing G. The second element E42 of the fourth planetary gear set P4 is connected in a rotationally fixed manner to the drive shaft WAn. The third element E43 of the fourth planetary gear set P4 is drive-effectively connected to the drive motor 2.Alternatively, the connection of the fourth planetary gear set P4 can also be different, wherein one of the elements E41, E42, E43 of the fourth planetary gear set P4 is connected in a rotationally fixed manner to the housing G, another of the elements E41, E42, E43 of the fourth planetary gear set P4 is drive-effective, i.e. is directly or indirectly connected or connectable, to the drive machine 2, and wherein another of the elements E41, E42, E43 of the fourth planetary gear set P4 is rotationally fixedly connected to the drive shaft WAn. The advantage of this pre-transmission designed as a planetary gear set is that higher transmission ratios can be achieved with the transmission 1. Otherwise, the exemplary embodiment corresponds to . Fig. 5 the embodiment according to Fig. 3, to which reference is made.

[0037] Fig. 6 shows a fourth embodiment of the drive device according to the invention. The drive device according to Fig. 6 essentially corresponds to the drive device according to Fig. 3, whereby a difference between these two embodiments lies in the arrangement of a constant gear ratio in the power flow between the drive motor 2 and the drive shaft WAn. In the present case, this pre-transmission is designed as a spur gear stage ST and comprises a first gear Z1, which is drivingly connected to the drive motor 2, and a second gear Z2, which is rotationally fixedly connected to the drive shaft WAn. The diameters of the two gears Z1, Z2 of the spur gear stage ST can be used to adjust the center distance of the drive motor 2 to the rotational axis R. Thus, the drive motor 2 is arranged axially parallel to the drive shaft WAn and to the two output shafts WAb1, WAb2. The advantage of this pre-transmission designed as a spur gear stage ST is that higher gear ratios can be achieved with the transmission 1. Otherwise, the embodiment according to Fig. 6 the embodiment according to Fig. 3, to which reference is made.

[0038] Fig. Figure 7 shows a fifth embodiment of the drive device according to the invention. The drive device according to Fig. 7 essentially corresponds to the drive device according to Fig. 3, wherein a difference between these two embodiments lies in the arrangement of a switching element S for generating a locking effect between the two output shafts WAb1, WAb2. In the present case, the switching element S is designed as a frictionally engaged switching element and, in a partially closed state, generates a torque between the two output shafts WAb1, WAb2. When the switching element S is fully closed, the two output shafts WAb1, WAb2 are connected to one another in a rotationally fixed manner via the switching element S. When the switching element S is fully open, no torque is transmitted between the two output shafts WAb1, WAb2 via the switching element S. For example, the switching element S can have one or more parallel-acting friction surfaces. Alternatively, the switching element S can have one or more conical friction surfaces.A transmission 1 with such a limited-slip differential enables particularly sporty driving. Otherwise, the embodiment shown in FIG. Fig. 7 the embodiment according to Fig. 3, to which reference is made.

[0039] Fig. Figure 8 shows a sixth embodiment of the drive device according to the invention. The drive device according to Fig. 8 essentially corresponds to the drive device according to Fig. 3, wherein a difference between these two embodiments lies in the arrangement of a shifting element S for generating a locking effect between the two output shafts WAb1, WAb2. In the present case, the shifting element S is designed as a positive-locking shifting element and, in a closed state, generates a locking torque between the two output shafts WAb1, WAb2 by connecting the two output shafts WAb1, WAb2 in a rotationally fixed manner. In an open state of the shifting element S, no locking torque is generated between the two output shafts WAb1, WAb2. For example, the shifting element S can have several positive-locking claws. A transmission 1 with such a limited-slip differential particularly supports traction when driving off-road. Otherwise, the embodiment according to Fig. 8 the embodiment according to Fig. 3, to which reference is made.

[0040] Fig. 9 shows a seventh embodiment of the drive device according to the invention. The drive device according to Fig. 9 essentially corresponds to the drive device according to Fig. 5, wherein a difference between these two embodiments lies in the arrangement of a first shifting element A for shifting a first gear and a second shifting element B for shifting a second gear in the power flow between the drive engine 2 and the drive shaft WAn. In the present case, both shifting elements A, B are designed as frictionally engaged shifting elements, for example as multi-plate clutches, and enable power shifting. When the first shifting element A is closed and the second shifting element B is open, the first element E41 of the fourth planetary gear set P4 is connected in a rotationally fixed manner to the housing G, and a first gear ratio is set.When the first shifting element A is open and the second shifting element B is closed, the fourth planetary gear set P4 is locked by the first element E41 of the fourth planetary gear set P4 and the third element E43 of the fourth planetary gear set P4 being connected in a rotationally fixed manner, thereby setting a second gear ratio. The advantage of such a 2-speed shifting device is that it enables high gear ratios at high top speeds. Otherwise, the exemplary embodiment corresponds to that shown in FIG. Fig. 9 the embodiment according to Fig. 5, to which reference is made.

[0041] The Fig. Figures 10 to 13 show different configurations of planetary gear sets. At least one of the planetary gear sets of the transmission according to the invention can be designed as a conventional positive planetary gear set, a negative stepped planetary gear set, a positive stepped planetary gear set with two sun gears, or a positive stepped planetary gear set with two ring gears, instead of as a conventional negative planetary gear set.

[0042] Fig. 10 shows a positive planetary gear set. The first element E1 of the positive planetary gear set is designed as a sun gear, the second element E2 of the positive planetary gear set is designed as a ring gear, and the third element E3 of the positive planetary gear set is designed as a planet carrier. The planet carrier of the positive planetary gear set guides at least one planetary gear pair consisting of a first planetary gear PR1 and a second planetary gear PR2. The first planetary gear PR1 meshes with the inner sun gear, and the second planetary gear PR2 meshes with the surrounding ring gear. Furthermore, the two planetary gears PR1, PR2 of a planetary gear pair also mesh with each other.

[0043] Fig. 11 shows a negative stepped planetary gear set. The first element E1 of the negative stepped planetary gear set is designed as a sun gear in the present case and can alternatively be designed as a ring gear. The second element E2 of the negative stepped planetary gear set is designed as a planet carrier. The third element E3 of the negative stepped planetary gear set is designed as a ring gear in the present case and can be designed as a sun gear if the first element E1 of the negative stepped planetary gear set is a ring gear. The planet carrier of the negative stepped planetary gear set guides at least one stepped planetary gear consisting of a first gear ZR1 and a second gear ZR2, wherein the two gears ZR1, ZR2 are connected to one another in a rotationally fixed and integral manner. In the present case, the first gear ZR1 of the stepped planetary gear has a smaller diameter than the second gear ZR2 of the stepped planetary gear.The first gear ZR1 of the stepped planetary gear meshes with the inner sun gear and the second gear ZR2 of the stepped planetary gear meshes with the surrounding ring gear.

[0044] Fig. 12 shows a plus stepped planetary gear set with two sun gears. The first element E1 of the plus stepped planetary gear set is designed as the first sun gear. The second element E2 of the plus stepped planetary gear set is designed as the second sun gear. The third element E3 of the plus stepped planetary gear set is designed as a planet carrier. The planet carrier of the plus stepped planetary gear set carries at least one stepped planetary gear consisting of a first gear ZR1 and a second gear ZR2, wherein the two gears ZR1, ZR2 are connected to one another in a rotationally fixed and integral manner. In this case, the first gear ZR1 of the stepped planetary gear has a larger diameter than the second gear ZR2 of the stepped planetary gear. The first gear ZR1 of the stepped planetary gear meshes with the first sun gear, and the second gear ZR2 of the stepped planetary gear meshes with the second sun gear.

[0045] Fig.13 shows a plus stepped planetary gear set with two ring gears. The first element E1 of the plus stepped planetary gear set is designed as a first ring gear. The second element E2 of the plus stepped planetary gear set is designed as a second ring gear. The third element E3 of the plus stepped planetary gear set is designed as a planet carrier. The planet carrier of the plus stepped planetary gear set guides at least one stepped planetary gear consisting of a first gear ZR1 and a second gear ZR2, wherein the two gears ZR1, ZR2 are connected to one another in a rotationally fixed and integral manner. In this case, the first gear ZR1 of the stepped planetary gear has a larger diameter than the second gear ZR2 of the stepped planetary gear. The first gear ZR1 of the stepped planetary gear meshes with the first ring gear, and the second gear ZR2 of the stepped planetary gear meshes with the second ring gear. Reference symbol 1 gearbox 2 drive machine W1 first coupling shaft W2 second coupling shaft WAn drive shaft WAb1 first output shaft WAb2 second output shaft G Housing A first switching element B second switching element S switching element R rotation axis P1 first planetary gear set E11 first element of the first planetary gear set E12 second element of the first planetary gear set E13 third element of the first planetary gear set P2 second planetary gear set E21 first element of the second planetary gear set E22 second element of the second planetary gear set E23 third element of the second planetary gear set P3 third planetary gear set E31 first element of the third planetary gear set E32 second element of the third planetary gear set E33 third element of the third planetary gear set P4 fourth planetary gear set E41 first element of the fourth planetary gear set E42 second element of the fourth planetary gear set E43 third element of the fourth planetary gear set E1 first element E2 second element E3 third element PR1 first planetary gear PR2 second planetary gear ZR1 first gear of the stepped planetary gear ZR2 second gear of the stepped planetary gear ST spur gear stage Z1 first gear of the spur gear stage Z2 second gear of the spur gear stage 100 motor vehicles 101 first wheel axle 102 second wheel axle R1 wheel R2 wheel R3 bike R4 wheel

Claims

[1] Transmission (1) for a motor vehicle (100), comprising • a first planetary gear set (P1), a second planetary gear set (P2) and a third planetary gear set (P3), each planetary gear set (P1, P2, P3) having a first element (E11, E21, E31), a second element (E12, E22, E32) and a third element (E13, E23, E33), • exactly one drive shaft (WAn) for connecting the transmission (1) to a drive engine (2) of the motor vehicle (100), • a first output shaft (WAb1) and a second output shaft (WAb2) each for connecting the transmission (1) to a wheel (R1, R2) of the motor vehicle (100), • a first coupling shaft (W1) and a second coupling shaft (W2) each for the rotationally fixed connection of two elements of two planetary gear sets (P1, P2, P3), • wherein one of the elements (E11, E21, E31) of the first planetary gear set (P1) is connected in a rotationally fixed manner to the first output shaft (WAb1), wherein another of the elements (E11, E21, E31) of the first planetary gear set (P1) is connected in a rotationally fixed manner to the first coupling shaft (W1), wherein another of the elements (E11, E21, E31) of the first planetary gear set (P1) is connected in a rotationally fixed manner to the second coupling shaft (W2), • wherein one of the elements (E12, E22, E32) of the second planetary gear set (P2) is connected in a rotationally fixed manner to the first coupling shaft (W1), wherein another of the elements (E12, E22, E32) of the second planetary gear set (P2) is connected in a rotationally fixed manner to a stationary component, wherein another of the elements (E12, E22, E32) of the second planetary gear set (P2) is connected in a rotationally fixed manner to the second output shaft (WAb2), • wherein one of the elements (E13, E23, E33) of the third planetary gear set (P3) is connected in a rotationally fixed manner to the second coupling shaft (W2), wherein another of the elements (E13, E23, E33) of the third planetary gear set (P3) is connected in a rotationally fixed manner to the input shaft (WAn), wherein another of the elements (E13, E23, E33) of the third planetary gear set (P3) is connected in a rotationally fixed manner to the second output shaft (WAb2). [2] Transmission according to claim 1, • wherein the first element (E11) of the first planetary gear set (P1) is connected in a rotationally fixed manner to the second coupling shaft (W2), wherein the second element (E12) of the first planetary gear set (P1) is connected in a rotationally fixed manner to the first coupling shaft (W1), wherein the third element (E13) of the first planetary gear set (P1) is connected in a rotationally fixed manner to the first output shaft (WAb1), • wherein the first element (E21) of the second planetary gear set (P2) is connected in a rotationally fixed manner to the second output shaft (WAb2), wherein the second element (E22) of the second planetary gear set (P2) is connected in a rotationally fixed manner to a stationary component, wherein the third element (E23) of the second planetary gear set (P2) is connected in a rotationally fixed manner to the first coupling shaft (W1), • wherein the first element (E31) of the third planetary gear set (P3) is connected in a rotationally fixed manner to the input shaft (WAn), wherein the second element (E32) of the third planetary gear set (P3) is connected in a rotationally fixed manner to the second output shaft (WAb2), wherein the third element (E33) of the third planetary gear set (P3) is connected in a rotationally fixed manner to the second coupling shaft (W2). [3] Transmission according to claim 2, wherein the third planetary gear set (P3) is arranged axially between the second planetary gear set (P2) and the first planetary gear set (P1). [4] Transmission (1) according to claim 1, • wherein the first element (E11) of the first planetary gear set (P1) is connected in a rotationally fixed manner to the second coupling shaft (W2), wherein the second element (E12) of the first planetary gear set (P1) is connected in a rotationally fixed manner to the first output shaft (WAb1), wherein the third element (E13) of the first planetary gear set (P1) is connected in a rotationally fixed manner to the first coupling shaft (W1), • wherein the first element (E21) of the second planetary gear set (P2) is connected in a rotationally fixed manner to the first coupling shaft (W1), wherein the second element (E22) of the second planetary gear set (P2) is connected in a rotationally fixed manner to a stationary component, wherein the third element (E23) of the second planetary gear set (P2) is connected in a rotationally fixed manner to the second output shaft (WAb2), • wherein the first element (E31) of the third planetary gear set (P3) is connected in a rotationally fixed manner to the input shaft (WAn), wherein the second element (E32) of the third planetary gear set (P3) is connected in a rotationally fixed manner to the second output shaft (WAb2), wherein the third element (E33) of the third planetary gear set (P3) is connected in a rotationally fixed manner to the second coupling shaft (W2). [5] Transmission according to claim 4, wherein the first planetary gear set (P1) is arranged axially between the third planetary gear set (P2) and the second planetary gear set (P1). [6] Transmission (1) according to one of the preceding claims, wherein at least one of the planetary gear sets (P1, P2, P3) is designed as a minus planetary gear set, wherein the first element (E11, E21, E31) of the respective planetary gear set (P1, P2, P3) is designed as a sun gear, wherein the second element (E12, E22, E32) of the respective planetary gear set (P1, P2, P3) is designed as a planet carrier, wherein the third element (E13, E23, E33) of the respective planetary gear set (P1, P2, P3) is designed as a ring gear. [7] Transmission (1) according to one of the preceding claims, wherein at least one of the planetary gear sets (P1, P2, P3) is designed as a plus planetary gear set, wherein the first element (E11, E21, E31) of the respective planetary gear set (P1, P2, P3) is designed as a sun gear, wherein the second element (E12, E22, E32) of the respective planetary gear set (P1, P2, P3) is designed as a ring gear, wherein the third element (E13, E23, E33) of the respective planetary gear set (P1, P2, P3) is designed as a planet carrier. [8] Transmission (1) according to one of the preceding claims, wherein a constant gear ratio stage is arranged in the power flow in front of the drive shaft (WAn). [9] Transmission (1) according to claim 8, wherein the constant gear ratio stage comprises a fourth planetary gear set (P4) with a first element (E41), a second element (E42) and a third element (E43). [10] Transmission (1) according to claim 8 or 9, wherein the constant gear ratio stage comprises a spur gear stage (ST) with a first gear (Z1) and a second gear (Z2). [11] Transmission (1) according to one of the preceding claims, wherein a first shifting element (A) for shifting a first gear and a second shifting element (B) for shifting a second gear are arranged in the power flow in front of the drive shaft (WAn). [12] Transmission (1) according to one of the preceding claims, wherein a switching element (S) for generating a locking effect is arranged between the two output shafts (WAb1, WAb2). [13] Drive device with a drive machine (2) and a transmission (1) according to one of claims 1 to 12. [14] Motor vehicle (100) with a drive device according to claim 13.

Images