Electric powertrain for a motor vehicle, in particular for a car

Abstract

Electric powertrain (10) for a motor vehicle, comprising: - a first electric machine (16) which has a first rotor (20); - a second electric machine (18) which has a second rotor (22); - a planetary gear set (42) comprising a first shaft (W1), a second shaft (W2), a third shaft (W3), a fourth shaft (W4) and a fifth shaft (W5); - a first vehicle wheel (12); - a second vehicle wheel (14), wherein, with respect to a torque flow emanating from the electric machines (16, 18) and extending towards the vehicle wheels (12, 14), the electric machines (16, 18) are arranged in the torque flow upstream of the planetary gear (42), which is arranged in the torque flow upstream of the vehicle wheels (12, 14); - a first switching element (S1) which is designed to couple the second rotor (22) to the first shaft (W1) in such a way that torques supplied by the second electric machine (18) via the second rotor (22) can be introduced into the planetary gear (42) at the first shaft (W1); and - a second switching element (S2) designed as a load-switchable switching element, which is designed to connect the third shaft (W3) to a sixth shaft (W6) in a rotationally fixed manner; characterized by - a third switching element (S3) designed as a positive-locking coupling, which is designed to connect the second shaft (W2) or the fourth shaft (W4) to the sixth shaft (W6) of the drive train (10) in a rotationally fixed manner; - a first transmission stage (46) which is arranged with respect to the torque flow downstream of the planetary gear (42) and upstream of the first vehicle wheel (12), wherein the fourth shaft (W4) is coupled or can be coupled to the first vehicle wheel (12) via the first transmission stage (46); and - a second transmission stage (48) which is arranged with respect to the torque flow downstream of the planetary gear (42) and upstream of the second vehicle wheel (14), wherein the fifth shaft (W5) is coupled or can be coupled to the second vehicle wheel (14) via the second transmission stage (48), and wherein a first transmission of the first transmission stage (46) is not equal to a second transmission of the second transmission stage (48).

Description

[0001] The invention relates to an electric drive train for a motor vehicle, in particular for a motor vehicle, according to the preamble of patent claim 1.

[0002] US 9 494 218 B2 discloses an engine for driving two driven parts for driving a vehicle.

[0003] The object of the present invention is to provide an electric drive train for a motor vehicle so that a particularly advantageous drivability can be realized.

[0004] This object is achieved by an electric drive train having the features of patent claim 1. Advantageous embodiments with expedient further developments of the invention are specified in the remaining claims.

[0005] The invention relates to an electric drive train for a motor vehicle, also simply referred to as a vehicle. This means that the motor vehicle, which is preferably designed as a motor vehicle, in particular as a passenger car, has the electric drive train in its fully manufactured state and can be driven by means of the electric drive train. The electric drive train has a first electric machine which has a first rotor. For example, the first electric machine has a first stator, by means of which the first rotor can be driven and is therefore rotatable in particular about a first machine axis of rotation relative to the first stator. For example, the first electric machine can provide first drive torques for driving the motor vehicle via its first rotor. The electric drive train has a second electric machine which has a second rotor.For example, the second electric machine has a second stator, by means of which the second rotor can be driven and is thus rotatable relative to the second stator, in particular about a second machine axis of rotation. It is conceivable for the electric machines to be arranged coaxially to one another, so that the machine axes of rotation coincide. Via its second rotor, the second electric machine can provide second drive torques for driving the motor vehicle. In particular, the motor vehicle can be driven, in particular purely electrically, by means of the electric machines, so that the motor vehicle is preferably designed as an electric vehicle, in particular as a battery-electric vehicle (BEV).The respective electrical machine is preferably designed as a high-voltage component whose electrical voltage, in particular electrical operating or nominal voltage, is preferably greater than 50 volts, in particular greater than 60 volts, and very preferably amounts to several hundred volts.

[0006] The electric drive train also has a planetary gear system, which has a first shaft, a second shaft, a third shaft, a fourth shaft, and a fifth shaft. For example, the electric drive train has a housing, wherein, for example, the planetary gear system is at least partially arranged in the housing. The first shaft, the second shaft, the third shaft, the fourth shaft, and the fifth shaft are five shafts of the planetary gear system. Preferably, the planetary gear system has exactly five shafts, namely the first shaft, the second shaft, the third shaft, the fourth shaft, and the fifth shaft. In particular, the respective shaft is rotatable about a shaft rotation axis relative to the housing.In particular, it is conceivable that the first electric machine and / or the second electric machine are arranged coaxially to the planetary gear, so that the first machine rotation axis and / or the second machine rotation axis coincide with the shaft rotation axis.

[0007] In particular, it is conceivable for the planetary gear train to have six gear elements. A first of the gear elements is, for example, a first sun gear, a second of the gear elements is, for example, a first planet carrier, a third of the gear elements is, for example, a first ring gear, a fourth of the gear elements is, for example, a second sun gear, a fifth of the gear elements is, for example, a second planet carrier, and a sixth of the gear elements is, for example, a second ring gear. The planetary gear train has the at least or exactly six gear elements and the at least or exactly five shafts, in particular in that, for example, two of the gear elements are connected to one another in a rotationally fixed manner, in particular permanently. In particular, for example, the first planet carrier is permanently rotationally fixedly connected to the second planet carrier.It is conceivable that the transmission elements connected to one another in a rotationally fixed manner are formed separately from one another and, in particular, permanently connected to one another in a rotationally fixed manner. Or the transmission elements connected to one another in a rotationally fixed manner are formed integrally, i.e., from a single piece and thus formed by a monoblock or designed as a monoblock. A monoblock is understood to mean a body manufactured in one piece, i.e., integrally, and thus an integral body, so that, for example, the transmission elements connected to one another in a rotationally fixed manner are formed by the integrally manufactured body and thus are not composed of separately formed and interconnected parts.

[0008] The electric drive train has a first vehicle wheel and a second vehicle wheel. The vehicle wheels are ground contact elements via which the drive train, and thus the motor vehicle as a whole, is or can be supported downwards on the ground in the vertical direction of the vehicle. If the motor vehicle is driven along the ground while being supported downwards on the ground in the vertical direction of the vehicle via the ground contact elements, the vehicle wheels roll, in particular directly, on the ground. In particular, the vehicle wheels are components of the same axle of the motor vehicle, also referred to as the vehicle axle.For example, in its fully manufactured state, the motor vehicle has at least or exactly two vehicle axles arranged one behind the other and thus consecutively in the longitudinal direction of the motor vehicle, namely the aforementioned vehicle axle as the first vehicle axle and a second vehicle axle. The aforementioned vehicle wheels are, for example, vehicle wheels of the first vehicle axle. The first vehicle axle can have at least or exactly two vehicle wheels, namely the first vehicle wheel and the second vehicle wheel. The second vehicle axle can, for example, have at least or exactly two further vehicle wheels, namely a third vehicle wheel and a fourth vehicle wheel, wherein the previous and following statements regarding the first vehicle wheel and the second vehicle wheel can readily be applied to the third vehicle wheel and the fourth vehicle wheel.When reference is made below to the vehicle wheels, this refers to the first vehicle wheel and the second vehicle wheel, unless otherwise stated. In particular, the electric motors can drive the vehicle wheels, in particular purely electrically, whereby the motor vehicle can be driven, in particular purely electrically. The vehicle wheels of the respective vehicle axle are arranged, for example, on opposite sides of the motor vehicle in the transverse direction of the motor vehicle.

[0009] With regard to a torque flow emanating from the electric machines, that is to say in particular from the respective rotor and running towards the vehicle wheels, the electric machines are arranged in the torque flow upstream of the planetary gear, which is arranged in the torque flow upstream of the vehicle wheels, whereby the vehicle wheels can be driven by the electric machines via the planetary gear.

[0010] The electric drive train has a first switching element which is designed to couple the second rotor to the first shaft in such a way that the respective second drive torque which can be provided or is provided by the second electric machine via the second rotor can be introduced at the first shaft and in particular via the first shaft into the planetary gear system. In other words, by means of the first switching element, the second rotor can be connected, i.e. coupled, to the first shaft in a torque-transmitting, in particular rotationally fixed, manner. In other words, the first switching element is designed to couple the second rotor to the first shaft in such a way that torques originating from the second rotor can be introduced at the first shaft into the planetary gear system.

[0011] The electric drive train also includes a second shifting element, which is provided in particular in addition to the first shifting element. The second shifting element is designed as a powershiftable shifting element, in particular as a friction clutch, in particular as a multi-plate clutch, whereby the friction clutch is also referred to as a friction clutch. Friction elements of the powershiftable shifting element can be either flat or conical, as in a conventional synchronizer, for example.

[0012] The second shifting element can also be designed with two stages. "Two-stage" here means that the second shifting element is frictionally engaged in a first actuation stage and positively engaged in a second actuation stage (as in a known positively engaged shifting element with synchronization). Thus, a frictional engagement can be established in the first actuation stage to perform the power shift, while a positive engagement is established in the second actuation stage to transmit the torque via the second shifting element without the use of actuation energy. In an advantageous embodiment, the second shifting element can be designed such that, in the frictional actuation stage, torque transmission can be ensured both when the clutch is engaging and disengaging.

[0013] The second shifting element is designed to non-rotatably connect the third shaft to a sixth shaft, which is provided in addition to the five shafts of the planetary gear set. In other words, the third shaft can be non-rotatably connected to the sixth shaft by means of the second shifting element. The sixth shaft is provided in addition to the five shafts of the planetary gear set and is not, for example, a component of the planetary gear set.

[0014] For example, the first switching element can be switched between a first coupled state and a first uncoupled state. In the first coupled state, the second rotor is coupled, in particular in a torque-transmitting manner, to the first shaft by means of the first switching element such that the respective second drive torque, which can be provided by the second electric machine via the second rotor, can be introduced into the planetary gear at the first shaft. In the first uncoupled state, the second rotor and the first shaft are decoupled from one another such that no torque can be transmitted between the second rotor and the first shaft via the first switching element. In particular, it is conceivable that in the first uncoupled state, the second rotor and the first shaft are rotatable relative to one another about the shaft axis of rotation or about the second machine axis of rotation.For example, in the first coupling state, the second rotor and the first shaft are connected to one another in a rotationally fixed manner by means of the first switching element. For example, the first switching element can be moved, in particular translationally and / or relative to the housing, between at least one first coupling position, which effects the first coupling state, and at least one first decoupling position, which effects the first decoupling state.

[0015] For example, the second switching element can be switched between a second coupling state and a second decoupling state. In the second coupling state, the third shaft is frictionally or positively connected to the sixth shaft by means of the second switching element. In the second decoupling state, the second switching element releases the third shaft for rotation about the shaft rotation axis relative to the sixth shaft, so that in the second decoupling state the third shaft and the sixth shaft are rotatable about the shaft rotation axis relative to one another and so that, in particular, no torque can be transmitted between the third shaft and the sixth shaft via the second switching element.For example, the second switching element can be moved, in particular translationally and / or relative to the housing, between at least one second coupling position bringing about the second coupling state and at least one second decoupling position bringing about the second decoupling state. In the context of the present disclosure, the feature that two components, such as the two transmission elements mentioned, are connected to one another in a rotationally fixed manner, is to be understood as meaning that the components connected to one another in a rotationally fixed manner are arranged coaxially to one another and, in particular when the components are driven, rotate together or simultaneously about an axis of rotation common to the components, such as the shaft rotation axis, at the same angular velocity, in particular relative to the housing.In other words, the term "rotatably connected" or "rotatably connected" can be understood as follows: Two elements are non-rotatably connected if they are arranged coaxially to one another and are connected to one another in such a way that they rotate at the same angular velocity, especially when driven. The feature that two components are connected to one another in a torque-transmitting manner means that the components are coupled or connected to one another in such a way that torque can be transmitted between the components. If the components are non-rotatably connected to one another, the components are also connected to one another in a torque-transmitting manner.

[0016] The feature that two components are permanently connected to one another in a torque-transmitting manner does not mean that a switching element is provided that can be switched between a coupled state that connects the components to one another in a torque-transmitting manner and a decoupling state in which no torque can be transmitted between the components via the switching element. Rather, the components are always, or always and thus permanently, connected to one another in a torque-transmitting manner, i.e., in such a way that torque can be transmitted between the components. Thus, for example, one of the components can be driven by the other component, or vice versa.In particular, the feature that two components are permanently connected to one another in a rotationally fixed manner is to be understood as meaning that a switching element is not provided which can be switched between a coupling state connecting the components to one another in a rotationally fixed manner and a decoupling state in which the components are decoupled from one another and can be rotated relative to one another so that no torque can be transmitted between the components via the switching element, but rather the components are always connected or coupled to one another, thus permanently rotationally fixed.

[0017] The feature that two components, such as the second rotor and the first shaft, can be connected or coupled to one another in a rotationally fixed or torque-transmitting manner, is to be understood as meaning that the components are assigned a switching element, such as the first switching element, which can be switched between at least one coupled state and at least one uncoupled state. In the coupled state, the components are connected to one another in a rotationally fixed or torque-transmitting manner by means of the switching element. In the uncoupled state, the components are decoupled from one another, such that in the uncoupled state the components can be rotated relative to one another, in particular about the component axis of rotation, such as the shaft axis of rotation, and in particular such that no torque can be transmitted between the components via the switching element.

[0018] For example, the sixth shaft is rotatable relative to the housing about an element rotation axis. Preferably, the sixth shaft is arranged coaxially with the five shafts of the planetary gear, so that the element rotation axis coincides with the shaft rotation axis.

[0019] In order to be able to realize particularly advantageous drivability of the electric drive train and thus of the motor vehicle as a whole, it is provided according to the invention that the electric drive train has a third switching element, which is provided in particular in addition to the first switching element and in addition to the second switching element and is designed as a positive coupling, in particular as a dog clutch. The third switching element is designed to connect the second shaft or the fourth shaft to the sixth shaft in a rotationally fixed manner. In other words, by means of the third switching element, the sixth shaft can be connected in a positive coupling to the second shaft or in a positive coupling to the fourth shaft. The second shaft and the fourth shaft are collectively also referred to as coupling shafts. The third switching element can be switched, for example, between a third coupling state and a third decoupling state.In the third coupling state, the sixth shaft is connected in a rotationally fixed manner to the coupling shaft, i.e., to one of the coupling shafts, in particular precisely, by means of the third switching element. In the third uncoupling state, the third switching element releases the sixth shaft for rotation about the element axis of rotation or about the shaft axis of rotation and relative to the one coupling shaft, so that in the third uncoupling state, the one coupling shaft and the sixth shaft are rotatable relative to one another about the element axis of rotation or about the shaft axis of rotation. In particular, the third switching element can be moved, for example, in particular translationally and / or relative to the housing, between at least one third coupling position bringing about the third coupling state and at least one third uncoupling position bringing about the third uncoupling state.

[0020] According to the invention, the electric drive train also has a first gear ratio, which, with respect to the torque flow, is arranged downstream of the planetary gear and upstream of the first vehicle wheel, so that the first vehicle wheel can be driven by the planetary gear via the first gear ratio. The fourth shaft is or can be coupled to the first vehicle wheel via the first gear ratio, in particular in a torque-transmitting manner, so that the first vehicle wheel can be driven by the fourth shaft via the first gear ratio.

[0021] Also provided is a second gear ratio, particularly in addition to the first gear ratio, which is arranged downstream of the planetary gear and upstream of the second vehicle wheel with respect to the torque flow, so that the second vehicle wheel can be driven by the planetary gear via the second gear ratio. The fifth shaft is coupled or can be coupled to the second vehicle wheel via the second gear ratio, in particular in a torque-transmitting manner, so that the second vehicle wheel can be driven by the fifth shaft via the second gear ratio.

[0022] The first gear ratio has a first gear ratio, particularly when viewed from the fourth shaft toward the first vehicle wheel. The second gear ratio has a second gear ratio, particularly when viewed from the fifth shaft toward the second vehicle. The first gear ratio is intended to be different from the second gear ratio. In other words, the first gear ratio differs from the second gear ratio. In particular, the absolute value of the first gear ratio is different from the absolute value of the second gear ratio.

[0023] In other words, with regard to the torque flow emanating from the electric machines, the electric machines are arranged upstream, i.e. upstream of the planetary gear, and the planetary gear is arranged upstream, i.e. upstream of the vehicle wheels, with regard to the torque flow.

[0024] The first gear ratio is arranged with respect to the torque flow between the planetary gear and the first vehicle wheel, and the second gear ratio is arranged with respect to the torque flow between the planetary gear and the second vehicle wheel.

[0025] The invention enables the electric drive train to be powershifted, thus achieving both particularly high driving dynamics and a particularly high level of ride comfort. The first gear ratio is also designated i1, and the second gear ratio is also designated i2. Because the third shifting element is designed as a positive clutch, losses can be kept particularly low, thus enabling particularly efficient operation.If the first gear ratio and the second gear ratio, in particular their absolute values, were equal, it would be difficult or even impossible, for example, to switch between two different operating modes of the electric drive train without interrupting the tractive force, because this would require the third switching element, designed, for example, as a claw switching element, to be opened, particularly at one end of a switching sequence to switch from a first of the operating modes to a second of the operating modes. However, a positive-locking switching element such as a claw switching element can or should only be opened, i.e. switched from its coupled state to its uncoupled state, when there is no load between the coupling halves of the claw switching element, i.e. between elements that can be connected to one another in a rotationally fixed manner by means of the claw switching element.This load-free state could be achieved, for example, by slipping the second shifting element, which is designed as a frictional clutch, but only if there is a difference in speed when driving straight ahead, in particular at the second shifting element, i.e. if there is a difference in speed between an input of the second shifting element and an output of the second shifting element and if, during shifting, the clutch half of the shifting element located downstream in the torque flow has a lower speed than the upstream clutch half. If the speeds were the same, the second shifting element, if it were designed as a positive-locking shifting element, would not be able to be engaged at all. A tooth-on-tooth position can only be resolved via relative speeds between the input and the output.When driving straight ahead, however, the aforementioned difference in speed does not usually occur, particularly because when driving straight ahead, the vehicle wheels rotate at the same speed in the same direction.However, since in the invention the planetary gear train, also referred to as a linkage or functioning as a linkage, is designed asymmetrically, the said differential speed arises at the second shifting element when the motor vehicle is traveling straight ahead, in particular between the input and the output of the second shifting element, whereby power shifting can be realized, in particular such that the third shifting element can be shifted, in particular opened, without a load and thus with an interruption in tractive force and in particular while the vehicle wheels are being driven by at least one of the electric machines or by both electric machines, the torque being transmitted via the first shifting element and the slipping second shifting element. The asymmetrical design of the planetary gear train is compensated for by an asymmetrical design of the two gear ratio stages.The asymmetrical design of the gear ratios is achieved by the fact that the first gear ratio and the second gear ratio, in particular their absolute values, differ from each other. In particular, it is conceivable that the second gear ratio, in particular the absolute value of the second gear ratio, is greater than the first gear ratio, in particular the absolute value of the first gear ratio.

[0026] The ratios of the two planetary stages and the two gear ratios are related to each other in such a way that in the first operating mode a classic differential operation with an ideal torque distribution of 50:50 between the two driven wheels takes place and that when cornering a corresponding speed compensation can take place at the wheels.

[0027] In particular, this makes it possible, for example, to switch from the aforementioned first operating mode to the aforementioned second operating mode without interruption of traction, i.e. without interruption of traction.

[0028] In a particularly advantageous embodiment of the invention, the planetary gear train comprises a first planetary gear set and a second planetary gear set. For example, the first planetary gear set comprises the first sun gear, the first planet carrier, and the first ring gear. For example, the second planetary gear set comprises the second sun gear, the second planet carrier, and the second ring gear. It is preferably provided that the first planet carrier of the first planetary gear set and the second planet carrier of the second planetary gear set are connected to one another, in particular permanently, in a rotationally fixed manner and form a common planet carrier, which is also referred to as the overall planet carrier.It is conceivable that the first planet carrier and the second planet carrier are formed separately from one another and, in particular, are permanently and non-rotatably connected to one another, or the first planet carrier and the second planet carrier are formed integrally with one another, thus consisting of a single piece. In this case, it is provided that one of the five shafts of the planetary gear set has the common planet carrier, thus the overall planet carrier. In other words, one of the five shafts comprises the common planet carrier. In other words, again in other words, the common planet carrier forms one of the five shafts, for example, so that the common planet carrier is a component of one of the five shafts of the planetary gear set.In particular, it is thus conceivable for the respective shaft to have a respective shaft section and at least or exactly one of the transmission elements, in particular exactly two of the transmission elements, wherein the respective shaft section of the respective shaft and the respective transmission element of the respective shaft are connected to one another in a rotationally fixed manner, in particular are permanently connected to one another in a rotationally fixed manner. In the aforementioned embodiment, it is thus conceivable for one of the five shafts to comprise a shaft section and the common planet carrier, thus the first planet carrier and the second planet carrier, wherein the shaft section of one of the five shafts is connected, in particular permanently, in a rotationally fixed manner to the overall planet carrier. This makes it possible to achieve particularly advantageous drivability.

[0029] The asymmetrical design of the planetary gear can be specified in that gear ratios within the first planetary gear set and within the second planetary gear set are selected such that for torques emanating from the first electric machine, the same torque results via a first torque transmission path at the first vehicle wheel as via a second torque transmission path at the second vehicle wheel.

[0030] The said shafts of the planetary gear are arranged such that the first torque transmission path runs from the first electric machine, further via the sixth shaft, further via the second shaft, further via the fourth shaft, further via the first gear stage to the first vehicle wheel, and that the second torque transmission path runs from the first electric machine, further via the sixth shaft, further via the second shaft, further via the fifth shaft, further via the second gear stage to the second vehicle wheel.

[0031] A further embodiment is characterized in that the first shaft comprises one of the sun gears of the planetary gear system, while the third shaft comprises another of the sun gears of the planetary gear system or one of the ring gears of the planetary gear system. This allows for particularly advantageous shiftability and thus particularly advantageous drivability.

[0032] In a further, particularly advantageous embodiment of the invention, the sixth shaft is coupled or can be coupled to the first rotor, in particular in a torque-transmitting and, most particularly, rotationally fixed manner, and is arranged, with respect to the torque flow, in the torque flow between the first rotor and the planetary gear, in particular upstream of the planetary gear and downstream of the first rotor. This allows for particularly advantageous drivability in a particularly space-efficient manner.

[0033] A further embodiment is characterized in that the first shaft has or includes the first sun gear. The third shaft has or includes the second sun gear, with the second shaft having or including the common planetary carrier. The fifth shaft, for example, has the first ring gear, and the fourth shaft has the second ring gear. This allows particularly advantageous gear ratios to be realized in a particularly space-efficient manner, thereby achieving particularly advantageous drivability.

[0034] In a further, particularly advantageous embodiment of the invention, the first planetary gears, second planetary gears, and third planetary gears of the planetary gear system are rotatably mounted on the common planetary carrier. The first planetary gears mesh with the first sun gear and the second planetary gears, and the second planetary gears mesh with the first ring gear and the second sun gear. The third planetary gears mesh with the second planetary gears and the second ring gear. This allows for a particularly advantageous gear ratio and thus particularly advantageous drivability.

[0035] In order to be able to provide particularly advantageous drivability in a particularly space-saving manner, it is provided in a further embodiment of the invention that the sixth shaft is connected, in particular permanently, in a rotationally fixed manner to the first rotor.

[0036] In a further, particularly advantageous embodiment of the invention, the sixth shaft is connected, in particular permanently, in a rotationally fixed manner to a first input shaft of the first gear ratio and, with respect to the torque flow, is arranged downstream of the planetary gear and, in particular, upstream of the first gear ratio. This allows for a particularly advantageous gear ratio and thus particularly advantageous drivability to be achieved in a space-efficient manner.

[0037] A further embodiment is characterized in that the first shaft comprises the first sun gear of the planetary gear, while the second shaft comprises the first ring gear of the planetary gear. The third shaft comprises the second ring gear of the planetary gear, and the fourth shaft comprises the second sun gear of the planetary gear. The fifth shaft comprises the common planetary carrier. This allows for a particularly advantageous gear ratio and thus particularly advantageous drivability to be realized in a particularly space-efficient manner.

[0038] Finally, in order to achieve particularly advantageous drivability, it has been shown to be particularly advantageous if first planetary gears, second planetary gears and third planetary gears are rotatably mounted on the common planetary carrier, wherein the first planetary gears mesh with the first sun gear and with the first ring gear, wherein the second planetary gears mesh with the second sun gear and with the first planetary gear, and wherein the third planetary gears mesh with the second planetary gears and with the second ring gear.

[0039] In the context of the present disclosure, the terms "axial" and "axial direction" refer to the shaft rotation axis of the planetary gear set, also referred to as the rotation axis. The planetary gear sets are advantageously arranged coaxially with one another. The electric motors and the transmission stages are advantageously arranged coaxially with the planetary gear set and thus with the shaft rotation axis.

[0040] It is conceivable that the respective gear ratio stage is designed as a respective, further planetary gear set provided in addition to the planetary gear, whereby a particularly advantageous gear ratio and thus particularly good drivability can be realized in a particularly space-saving manner.

[0041] Further advantages, features, and details of the invention will become apparent from the following description of preferred embodiments and from the drawings. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown in the figures alone, can be used not only in the respective specified combinations, but also in other combinations or on their own, without departing from the scope of the invention.

[0042] The drawing shows: Fig. 1 is a schematic representation of a first embodiment of an electric drive train for a motor vehicle; Fig. 2 a schematic representation of a second embodiment of the electric drive train; and Fig. 3 a schematic representation of a third embodiment of the electric drive train.

[0043] In the figures, identical or functionally identical elements are provided with the same reference numerals.

[0044] Fig. 1 shows a schematic perspective view of a first embodiment of an electric drive train 10 for a motor vehicle, also simply referred to as a vehicle. This means that the motor vehicle, in its fully manufactured state, has the electric drive train 10 and can be driven by means of the electric drive train 10. The motor vehicle, which is preferably designed as a motor vehicle, in particular as a passenger car, has, in its fully manufactured state, at least or exactly two vehicle axles arranged one behind the other and thus consecutively in the longitudinal direction of the vehicle, also simply referred to as axles. The respective vehicle axle has at least or exactly two vehicle wheels, also simply referred to as wheels. The respective vehicle wheels of the respective vehicle axle are arranged on opposite sides of the motor vehicle in the transverse direction of the motor vehicle.The electric drive train 10 comprises at least or exactly one of the vehicle axles and thus the at least or exactly two vehicle wheels of the at least or exactly one vehicle axle of the electric drive train 10. The vehicle wheels of the drive train 10 are in . Fig. 1 is shown particularly schematically and designated 12 and 14. The vehicle wheel 12 is also referred to as the first vehicle wheel, and the vehicle wheel 14 is also referred to as the second vehicle wheel. The vehicle wheels of the motor vehicle are ground contact elements by means of which the motor vehicle can be or is supported downwards on a ground in the vertical direction of the motor vehicle. If the motor vehicle is driven along the ground while being supported downwards on the ground in the vertical direction of the vehicle via the ground contact elements, the vehicle wheels of the motor vehicle roll, in particular directly, on the ground.

[0045] The electric drive train 10 comprises a first electric machine 16 and a second electric machine 18, wherein the vehicle wheels 12 and 14 can be driven, in particular purely electrically, by means of the electric machines 16 and 18. As a result, the motor vehicle can be driven, in particular purely electrically.

[0046] The first electric machine 16 has a first rotor 20, via which the first electric machine 16 can provide first drive torques for driving the vehicle wheels 12 and 14. The second electric machine 18 has a second rotor 22, via which the second electric machine 18 can provide second drive torques for driving the vehicle wheels 12 and 14.

[0047] The first electrical machine 16 has a first stator 24, by means of which the first rotor 20 can be driven and thereby rotated about a first machine rotation axis 26 relative to the first stator 24 and also relative to a Fig. 1 particularly schematically illustrated housing 28 of the electric drive train 10. The second electric machine 18 has a second stator 30, by means of which the second rotor 22 can be driven and is thereby rotatable about a second machine rotation axis 32 relative to the stator 30 and also relative to the housing 28. In the Fig. In the first embodiment shown in Figure 1, the electrical machines 16 and 18 are arranged coaxially with each other so that the machine rotation axes 26 and 32 coincide.

[0048] Out of Fig. 1 shows that the respective electrical machine 16, 18 is designed as an axial flux machine. The respective rotor 20, 22 has two rotor elements 34 and 36, or 38 and 40, designed, for example, as rotor disks. The respective rotor elements 34 and 36, or 38 and 40 of the respective electrical machine 16, 18 are spaced apart from one another in the axial direction of the respective electrical machine 16, 18 and thus along the respective machine rotation axis 26, 32.In this case, a respective partial region of the respective stator 24, 30 of the respective electrical machine 16, 18 is arranged in the axial direction of the respective electrical machine 16, 18 between the respective rotor elements 34 and 36 or 38 and 40, such that the respective rotor element 34, 36, 38, 40 of the respective electrical machine 16, 18 is at least partially overlapped or covered by the respective partial region of the respective stator 24, 30 of the respective electrical machine 16, 18 in a direction running in the axial direction of the respective electrical machine 16, 18 and pointing towards the respective other rotor element 36, 34, 40, 38.

[0049] The electric drive train 10 has a planetary gear 42, which in particular has at least or exactly five shafts, namely a first shaft W1, a second shaft W2, a third shaft W3, a fourth shaft W4 and a fifth shaft W5. The respective shaft W1, W2, W3, W4, W5 is rotatable about a respective shaft rotation axis 44 relative to the housing 28. In the first embodiment, the planetary gear 42 is arranged coaxially to the respective electric machine 16, 18, such that the shaft rotation axis 44 coincides with the machine rotation axis 26 and with the machine rotation axis 32. In particular, the planetary gear 42 is at least partially arranged in the housing 28.

[0050] With regard to a torque flow emanating from the electric machines 16 and 18 and running towards the vehicle wheels 12 and 14, along which, for example, the respective drive torque from the respective electric machine 16, 18 can be or is transmitted to the respective vehicle wheel 12, 14 in order to thereby drive the respective vehicle wheel 12, 14, the electric machines 16 and 18 are arranged in the torque flow upstream of the planetary gear 42 arranged in the torque flow, so that the vehicle wheels 12 and 14 can be driven by the electric machines 16 and 18, in particular by the rotors 20 and 22, via the planetary gear 42.

[0051] The electric drive train 10 has a first switching element S1, which is designed to couple the second rotor 22 to the first shaft W1, in particular in a torque-transmitting and very particularly rotationally fixed manner, such that the respective second drive torque provided or capable of being provided by the second electric machine 18 via the second rotor 22 can be introduced at the first shaft W1 and via the first shaft W1 into the planetary gear 42.

[0052] The electric drive train 10 also has a second shifting element S2, which is designed as a power-shiftable clutch, in particular a frictional clutch, in particular a multi-disk clutch or multi-disk brake. The second shifting element S2 can be designed as a two-stage clutch with a frictional part, e.g., a cone clutch as the synchronization element, and a positive-locking part, e.g., a dog clutch as the positive-locking element.

[0053] The second shifting element S2 is designed to connect the third shaft W3 frictionally or non-positively during a module change between a first operating mode and a second operating mode with a sixth shaft W6 provided in addition to the five shafts W1, W2, W3, W4 and W5 of the planetary gear 42, in particular in a torque-transmitting manner and, in particular at the end of the shifting operation, in a rotationally fixed manner. Fig. 1, the sixth shaft W6 is connected, in particular permanently, in a rotationally fixed manner to the first rotor 20, so that, for example, the respective first drive torque that can be provided or is provided by the first electric machine 16 via the first rotor 20 can be introduced at the third shaft W3 and via the third shaft W3 into the planetary gear 42.

[0054] The electric drive train 10 further comprises a third shifting element S3, which is designed as a positive-locking clutch, in particular as a claw clutch or claw shifting element. In the first embodiment, the third shifting element S3 is designed to connect the second shaft W2 to the sixth shaft W6 in a positive-locking and rotationally fixed manner.

[0055] Furthermore, the electric drive train 10 has a first gear ratio 46, which, with respect to the torque flow, is arranged downstream of the planetary gear 42 and upstream of the first vehicle wheel 12. The fourth shaft W4 is coupled to the first vehicle wheel 12 via the first gear ratio 46, in particular in a torque-transmitting and, most particularly, permanently torque-transmitting manner. Thus, the first vehicle wheel 12 can be driven by the fourth shaft W4 via the first gear ratio 46.

[0056] The electric drive train 10 also includes a second gear ratio 48, which, with respect to the torque flow, is arranged upstream of the vehicle wheel 14 and downstream of the planetary gear 42. As a result, the second vehicle wheel 14 can be driven by the planetary gear 42 via the second gear ratio 48. The fifth shaft W5 is coupled to the second vehicle wheel 14 via the second gear ratio 48, in particular in a torque-transmitting and very particularly permanently torque-transmitting manner, so that the second vehicle wheel 14 can be driven by the fifth shaft W5 via the second gear ratio 48. The first gear ratio 46 has a first gear ratio, in particular with a first absolute value. The second gear ratio 48 has a second gear ratio, in particular with a second absolute value.The gear ratios, in particular the absolute values ​​of the gear ratios, are unequal, so that, for example, the second gear ratio, in particular the absolute value of the second gear ratio, is greater or smaller than the first gear ratio, in particular the absolute value of the first gear ratio. The planetary gear 42 forms or is a coupling gear or is also referred to as a coupling gear. For example, the shifting elements S2 and S3 form a changeover device, since advantageous switchability or switchability, in particular between at least two operating modes, the first operating mode and the second operating mode, of the electric drive train 10, can be realized by means of the shifting elements S2 and S3.

[0057] The planetary gear set 42 has a first planetary gear set 50 with a first sun gear 52, a first planet carrier 54, and a first ring gear 56. The planetary gear set 42 also has a second planetary gear set 58 with a second sun gear 60, a second planet carrier 62, and a second ring gear 64. The planet carriers 54 and 62 are also referred to as carriers, with the planet carrier 54 also being referred to as the first carrier and the planet carrier 62 also being referred to as the second carrier. In the first embodiment, the planet carriers 54 and 62 are connected to one another in a rotationally fixed manner, for example in such a way that the planet carriers 54 and 62 are formed separately from one another and connected to one another in a rotationally fixed manner, or for example in such a way that the planet carriers 54 and 62 are formed integrally with one another, i.e., are formed from a single piece. In particular, the planet carriers 54 and 62 are permanently connected to one another in a rotationally fixed manner.As a result, the planet carriers 54 and 62 form a common planet carrier 63, which is also referred to as the overall planet carrier. The overall planet carrier forms one of the five shafts W1, W2, W3, W4, and W5 of the planetary gear 42. In other words, one of the five shafts W1, W2, W3, W4, and W5 of the planetary gear 42 comprises the overall planet carrier. In the embodiment shown in . Fig. In the first embodiment shown in Figure 1, one of the five shafts W1, W2, W3, W4, and W5 of the planetary gear 42 is the second shaft W2, so that in the first embodiment, the second shaft W2 comprises the overall planetary carrier. In other words, in the first embodiment, the overall planetary carrier forms the second shaft W2. This means that in the first embodiment, the overall planetary carrier is a component of the second shaft W2.

[0058] For example, the respective shaft W1, W2, W3, W4, W5 of the planetary gear 42 has a respective shaft section, via which, for example, the respective shaft W1, W2, W3, W4, W5 of the planetary gear 42 is rotatably mounted at least indirectly on the housing 28. Furthermore, the respective shaft W1, W2, W3, W4, W5 of the planetary gear 42 has, for example, a respective element section, provided in particular in addition to the respective shaft section, which is designed or functions as a respective gear element of the planetary gear 42, in particular of the respective planetary gear set 50, 58. In the first embodiment, with regard to the second shaft W2, the element section of the second shaft W2 is a planet carrier section, which has or forms the overall planet carrier or is formed by the overall planet carrier. The planet carrier section will be explained in more detail below.In other words, the planet carrier section of the shaft W2 is formed by the planet carriers 54 and 62 or comprises the planet carriers 54 and 62. The sun gears 52 and 60, the planet carriers 54 and 62 and the ring gears 56 and 64 are gear elements of the planetary gear 42, in particular of the respective planetary gear set 50, 58. The respective gear element is rotatable about the shaft rotation axis 44 relative to the housing 28.

[0059] Since, in particular precisely, two of the six gear elements of the planetary gear 42, in this case the planet carriers 54 and 62, are connected to one another in a rotationally fixed manner, in particular permanently rotationally fixed, the six gear elements of the planetary gear 42 form the five shafts W1, W2, W3, W4 and W5 of the planetary gear 42. In particular, it can be provided that the five shafts W1, W2, W3, W4 and W5 of the planetary gear 42 are rotatable in pairs about the shaft rotation axis 44 relative to one another.

[0060] In the first embodiment, the first shaft W1 has the first sun gear 52, so that the element section of the first shaft W1 in the first embodiment has the sun gear 52 or is formed by the sun gear 52. In the first embodiment, the third shaft W3 has the second sun gear 60, so that the element section of the third shaft W3 has the second sun gear 60 or is formed by the second sun gear 60. In the first embodiment, the sixth shaft W6 is connected, in particular permanently, in a rotationally fixed manner to the first rotor 20 and thus coupled, wherein the sixth shaft W6 is arranged with regard to the torque flow in the torque flow between the first rotor 20 and the planetary gear 42, in particular downstream of the first rotor 20 and upstream of the planetary gear 42, so that the planetary gear 42 can be driven by the first rotor 20 via the sixth shaft W6.In the first embodiment, the fifth shaft W5 has the first ring gear 56, so that the element portion of the fifth shaft W5 has the ring gear 56 or is formed by the ring gear 56. In the first embodiment, the fourth shaft W4 has the second ring gear 64, so that the element portion of the fourth shaft W4 is formed by the second ring gear 64 or has the second ring gear 64.

[0061] In the first embodiment, the planetary gear set 42 has first planet gears P1, second planet gears P2, and third planet gears P3. The planet gears P1, P2, and P3 are rotatably mounted on the overall planet carrier. In the first embodiment, it is provided that the element section of the shaft W2 has the overall planet carrier or is formed by the overall planet carrier, wherein the planet gears P1, P2, and P3 are rotatably mounted on the overall planet carrier, thus rotatably on the element section of the second shaft W2. The first planet gears P1 mesh with the first sun gear 52 and with the second planet gears P2, in particular with first toothed sections of the second planet gears P2.The second planetary gears P2 mesh with the first ring gear 56 and with the second sun gear 60, in particular such that the respective first toothed sections of the second planetary gears P2 mesh with the ring gear 56 and respective second toothed sections of the planetary gears P2 mesh with the sun gear 60. In this case, it is particularly conceivable for the respective first toothed section and the respective second toothed section of the respective second planetary gear P2 to be arranged consecutively in the axial direction of the respective second planetary gear P2, i.e., one behind the other. For example, the respective first toothed section of the respective second planetary gear P2 is formed by a respective first toothing of the respective second planetary gear P2, wherein, for example, the respective second toothed section of the respective second planetary gear P2 is formed by a respective second toothing of the respective second planetary gear P2.The third planetary gears P3 mesh with the second ring gear 64 and with the second planetary gears P2, in particular with the second toothed sections of the second planetary gears P2. The first toothing preferably has a first pitch circle diameter and a first pitch circle diameter. The second toothing has a second pitch circle diameter and a second pitch circle diameter. Preferably, the first pitch circle diameter and the second pitch circle diameter differ from one another. Alternatively or additionally, the first pitch circle diameter and the second pitch circle diameter differ from one another.

[0062] In the first embodiment, for example, the second pitch circle diameter or the second pitch circle diameter is larger than the first pitch circle diameter or the first pitch circle diameter. Thus, for example, the respective second planetary gear P2 is designed as a stepped planetary gear, also referred to as a stepped planet. In particular, the first toothing and the second toothing are connected to one another, in particular permanently, in a rotationally fixed manner. For example, the first toothing and the second toothing are formed integrally with one another, i.e., from a single piece.Overall, it can be seen that in the first embodiment, the planetary gears P1 mesh with the first sun gear 52 and with the second planetary gears P2, in particular with the first toothed sections of the second planetary gears P2, wherein the planetary gears P1 do not mesh with the first ring gear 56, with the second ring gear 64, with the second sun gear 60, and with the third planetary gears P3. The second planetary gears P2, in particular the second toothed sections, mesh with the third planetary gears P3, and the second planetary gears P2, in particular the second toothed sections, mesh with the second sun gear 60. The second planetary gears P2, in particular the first toothed sections, mesh with the first ring gear 56, and the second planetary gears P2, in particular the first toothed sections, mesh with the first planetary gears P1. The second planetary gears P2 do not mesh with the first sun gear 52 and not with the second ring gear 64.The third planetary gears P3 mesh with the second planetary gears P2, in particular with the second toothed sections, and the third planetary gears P3 mesh with the second ring gear 64. The third planetary gears P3 do not mesh with the first sun gear 52, the first ring gear 56, the second sun gear 60, or the first planetary gears P1. Furthermore, the first embodiment provides that the sixth shaft W6 is connected, in particular permanently, in a rotationally fixed manner to the first rotor 20.

[0063] The respective gear ratio stage 46, 48 is designed as a respective further planetary gear set 66, 68 provided in addition to the planetary gear 42 and thus to the planetary gear sets 50 and 58. The respective further planetary gear set 66, 68 has a respective further sun gear 70, 72, a respective further planet carrier 74, 76, and a respective further ring gear 78, 80. In the first embodiment, the respective sun gear 70, 72 is designed as a respective input of the respective gear ratio stage 46, 48 such that the sun gear 70 is or can be connected to the fourth shaft W4 in a torque-transmitting manner, in particular in a rotationally fixed manner, and such that the sun gear 72 is or can be connected to the fifth shaft W5 in a torque-transmitting manner, in particular in a rotationally fixed manner.In the first embodiment, the sun gear 70 is permanently connected to the fourth shaft W4 in a torque-transmitting manner, in particular permanently rotationally fixed, and in the first embodiment, the sun gear 72 is permanently connected to the fifth shaft W5 in a torque-transmitting manner, in particular permanently rotationally fixed. The respective planetary carrier 74, 78 is a respective output of the respective gear ratio stage 46, 48, in this case such that the vehicle wheel 12 can be driven by the planetary carrier 74 and the vehicle wheel 14 by the planetary carrier 76. In particular, the vehicle wheel 12 can be connected or is connected to the planetary carrier 74 in a torque-transmitting manner, in particular permanently torque-transmitting, and the vehicle wheel 14 can be connected or is connectable, in particular permanently, torque-transmitting, to the planetary carrier 76. The respective ring gear 78, 80 can be connected or is connected to the housing 28 in a rotationally fixed manner.In the first embodiment, the respective ring gear 78, 80 is permanently connected to the housing 28 in a rotationally fixed manner. The respective further planetary gear set 66, 68 has respective further planet gears 82, 84, wherein the planet gears 82 are rotatably mounted on the planet carrier 74 and the planet gears 84 are rotatably mounted on the planet carrier 76. The planet gears 82 mesh simultaneously with the sun gear 70 and the ring gear 78, and the planet gears 84 mesh simultaneously with the sun gear 72 and the ring gear 80.

[0064] Fig. 2 shows a schematic representation of a second embodiment of the electric drive train 10. In the second embodiment, the sixth shaft W6 is connected, in particular permanently, in a rotationally fixed manner to a first input shaft 86 of the first gear ratio stage 46, wherein it is conceivable for the sixth shaft W6 and the first input shaft 86 to be integrally formed with one another, i.e., made from a single piece. The first input shaft 86 has the sun gear 70, so that the sun gear 70 is or forms an element section of the input shaft 86. For example, the first input shaft 86 is rotatably mounted at least indirectly on the housing 28 via its shaft section. With regard to the torque flow, the sixth shaft W6 is arranged downstream of the planetary gear 42 and upstream of the sun gear 70 or the first input shaft 86.In the second embodiment, the first shaft W1 includes the first sun gear 52, and the second shaft W2 includes the first ring gear 56. Thus, in the second embodiment, the element portion of the first shaft W1 is formed by the sun gear 52, and the element portion of the shaft W2 is formed by the ring gear 56. The third shaft W3 includes the second ring gear 64, and the fourth shaft W4 includes the second sun gear 60. In the second embodiment, the fifth shaft W5 includes the common planetary carrier 63 (overall planetary carrier).

[0065] In the second embodiment, the planet gears P1 and P2 are rotatably mounted on the overall planet carrier. There are no third planet gears in the second embodiment. Provision is made for the first planet gears P1, in particular the respective first toothed portions of the first planet gears P1, to mesh with the first sun gear 52 and with the first ring gear 56. The second planet gears P2 mesh with the second sun gear 60 and with the first planet gears P1, in particular with the respective second toothed portions of the first planet gears P1 and with the second ring gear 64. Overall, it can be seen that the first planet gears P1, in particular the first toothed portions of the first planet gears P1, mesh with the first sun gear 52 and with the first ring gear 56, and the first planet gears P1, in particular the second toothed portions of the planet gears P1, mesh with the second planet gears P2.In particular, it is conceivable for the first gear section and the second gear section, or the first gear and the second gear, to have the same pitch circle diameter or pitch circle diameter, so that, for example, the first pitch circle diameter and the second pitch circle diameter, or the first pitch circle diameter and the second pitch circle diameter, are the same in the second embodiment. The second planetary gears P2 mesh with the second sun gear 60, the second ring gear 64, and with the first planetary gears P1, in particular with the second gear sections of the first planetary gears P1.

[0066] The second planetary gears P2 do not mesh with the first sun gear 52 and not with the first ring gear 56.

[0067] In the third embodiment, the sixth shaft W6 is coupled, in particular permanently, in a torque-transmitting, in particular rotationally fixed manner, to the first rotor 20, i.e., connected and, with regard to the torque flow, arranged in the torque flow between the first rotor 20 and the planetary gear set 42. In the third embodiment, the planetary gear set 42 has at least or exactly three planetary gear sets, namely the first planetary gear set 50, the second planetary gear set 58, and a third planetary gear set 88, which is provided in addition to the planetary gear sets 50 and 58 and also in addition to the gear ratios 46 and 48. The third planetary gear set 88 has a third sun gear 90, a third planet carrier 92, also referred to as the third carrier, and a third ring gear 94.

[0068] Thus, the planetary gear train 42 has, in particular, at least or exactly nine gear elements, namely the sun gears 52, 60 and 90, the planet carriers 54, 62 and 92 and the ring gears 56, 64 and 94. In the third embodiment, the planetary gear train 42 also has, in particular, at least or exactly five shafts, namely the shafts W1, W2, W3, W4 and W5. This is achieved, on the one hand, in that in the third embodiment the planet carriers 54 and 62 are connected to one another, in particular permanently, in a rotationally fixed manner and thereby form the shaft W5 in the third embodiment. Thus, in the third embodiment the shaft W5 comprises the common planet carrier 63 (overall planet carrier). In other words, again in the third embodiment it is provided that the element section of the fifth shaft W5 has the overall planet carrier or is formed by the overall planet carrier.Furthermore, in the third embodiment, it is provided that the ring gear 94 is connected, in particular permanently, in a rotationally fixed manner to the sun gear 52, so that the ring gear 94 and the sun gear 52 form the shaft W1. In other words, the shaft W1 has the sun gear 52 and the ring gear 94, so that a first element section of the shaft W1 is or has the sun gear 52 or is formed by the sun gear 52, and so that a second element section of the shaft W1 is or has the ring gear 94 or is formed by the ring gear 94. Furthermore, in the third embodiment, the sun gear 90 is connected, in particular permanently, in a rotationally fixed manner to the sun gear 60, whereby the sun gears 90 and 60 form the third shaft W3.In other words, the shaft W3 has the sun gears 60 and 90, so that a first element section of the shaft W3 is or has the sun gear 60 or is formed by the sun gear 60, and so that a second element section of the shaft W3 is or has the sun gear 90 or is formed by the sun gear 90. In addition, the ring gears 64 and 56 are connected to one another, in particular permanently, in a rotationally fixed manner, whereby the ring gears 64 and 56 form the shaft W4. In other words, the shaft W4 has the ring gears 64 and 56. Thus, it is provided that a first element section of the shaft W4 is or has the ring gear 64 or is formed by the ring gear 64, and so that a second element section of the shaft W4 is or has the ring gear 56 or is formed by the ring gear 56. The shaft W2 has the third planet carrier 92, so that the element section of the shaft W2 has the planet carrier 92 or is formed by the planet carrier 92.Overall, it can be seen that the shaft W1 has the sun gear 52 and the ring gear 94, which are connected to one another, in particular permanently and in a rotationally fixed manner. The shaft W2 has the planet carrier 92. The shaft W3 has the sun gears 60 and 90, which are connected to one another, in particular permanently and in a rotationally fixed manner. The shaft W4 has the ring gears 56 and 64, which are connected to one another, in particular permanently and in a rotationally fixed manner. The shaft W5 has the common planet carrier 63 and thus the planet carriers 54 and 62, which are connected to one another, in particular permanently and in a rotationally fixed manner. In the third embodiment, the shaft W4 is connected, in particular permanently, in a torque-transmitting, in particular rotationally fixed, manner to the input of the transmission stage 46, thus to the sun gear 70 of the planetary gear set 66.The shaft W5 is connected, in particular permanently, in a torque-transmitting, in particular rotationally fixed manner, to the input of the gear ratio stage 48, thus to the sun gear 72 of the planetary gear set 68. In the second embodiment, the shaft W5 is connected, in particular permanently, in a torque-transmitting, in particular rotationally fixed manner, to the input of the gear ratio stage 48, thus to the sun gear 72 of the planetary gear set 68. In the first embodiment, the shaft W4 is connected, in particular permanently, in a torque-transmitting, in particular rotationally fixed manner, to the input of the gear ratio stage 46, thus to the sun gear 70 of the planetary gear set 66. In the first embodiment, the shaft W5 is connected, in particular permanently, in a torque-transmitting, in particular rotationally fixed manner, to the input of the gear ratio stage 48, thus to the sun gear 72 of the planetary gear set 68.In the third embodiment, the shaft W1 can be connected to the second rotor 22 of the second electric machine 18 in a torque-transmitting, in particular rotationally fixed, manner by means of the switching element S1. The sixth shaft W6 can be connected to the third shaft W3 by means of the second switching element S2. And the second shaft W2 can be connected to the sixth shaft W6 and thus to the first rotor 20 by means of the switching element S3. In the second embodiment, the fourth shaft W4 can be connected to the sixth shaft W6 in a rotationally fixed manner by means of the switching element S3. In the embodiments, the transmission stages 46 and 48 are arranged coaxially to one another and coaxially to the planetary gear 42 and coaxially to the electric machines 16 and 18. In the third embodiment, the third planetary gear set 88 is arranged coaxially to the planetary gear sets 50 and 58 and also coaxially to the gear ratios 46 and 48 and coaxially to the electric machines 16 and 18.The sun gear 90, the planet carrier 92 and the ring gear 94 are further transmission elements that can be rotated about the shaft rotation axis 44 relative to the housing 28.

[0069] In the third embodiment, the planetary gear set 42 also includes the planetary gears P1, P2, and P3. Furthermore, the planetary gear set 42 includes fourth planetary gears P4, which are, in particular, planetary gears of the third planetary gear set 88. The fourth planetary gears P4 are rotatably mounted on the planet carrier 92. The first planetary gears P1 mesh with the first sun gear 52 and with the second planetary gears P2. The first planetary gears P1 do not mesh with the first ring gear 56, the third planetary gears P3, the second sun gear 60, the second ring gear 64, the third sun gear 90, the fourth planetary gears P4, or the third ring gear 94. The second planetary gears P2 mesh with the first planetary gears P1 and the first ring gear 56.The second planetary gears P2 do not mesh with the first sun gear 52, the third planetary gears P3, the second sun gear 60, the second ring gear 64, the third sun gear 90, the fourth planetary gears P4, or the third ring gear 94. The third planetary gears P3 mesh with the second sun gear 60 and the second ring gear 64. The third planetary gears P3 do not mesh with the first sun gear 52, the first planetary gears P1, the first ring gear 56, the second planetary gears P2, the third sun gear 90, the fourth planetary gears P4, or the third ring gear 94. The fourth planetary gears P4 mesh with the third sun gear 90 and the third ring gear 94.The fourth planetary gears P4 do not mesh with the first sun gear 52, with the first planetary gears P1, with the first ring gear 56, with the third planetary gears P3, with the second sun gear 60, with the second planetary gears P2, and with the second ring gear 64.

[0070] Out of Fig.3 also shows that the third planetary gear set 88 is arranged between the electric machines 16 or 18 in the axial direction of the drive train 10 and thus along the shaft rotation axis 44, in particular such that the planetary gear set 88 is arranged on a side of the electric machine 16 facing the electric machine 18 in the axial direction of the drive train 10, and such that the planetary gear set 88 is arranged on a side of the electric machine 18 facing the electric machine 16 in the axial direction of the drive train 10 and facing away from the planetary gear sets 50 and 58. Accordingly, the planetary gear sets 50 and 58 are arranged on a side of the electric machine 18 facing away from the third planetary gear set 88 in the axial direction of the drive train 10. List of reference symbols 10 electric drivetrain 12 first vehicle wheel 14 second vehicle wheel 16 first electric machine 18 second electric machine 20 first rotor 22 second rotor 24 first stator 26 first machine rotation axis 28 housings 30 second stator 32 second machine rotation axis 34 Rotor element 36 Rotor element 38 Rotor element 40 rotor element 42 planetary gears 44 Shaft rotation axis 46 first translation level 48 second translation stage 50 first planetary gear set 52 first sun gear 54 first planet carrier 56 first ring gear 58 second planetary gear set 60 second sun gear 62 second planet carrier 63 common planet carrier 64 second ring gear 66 planetary gear set 68 planetary gear set 70 Sun gear 72 Sun gear 74 planet carriers 76 planet carriers 78 ring gear 80 ring gear 82 Planetary gear 84 Planetary gear 86 first input shaft 88 third planetary gear set 90 third sun gear 92 third planet carrier 94 third ring gear P1 first planet gear P2 second planet gear P3 third planet gear P4 fourth planet gear S1 first switching element S2 second switching element S3 third switching element W1 first wave W2 second wave W3 third wave W4 fourth wave W5 fifth wave W6 sixth wave

Claims

[1] Electric drive train (10) for a motor vehicle, comprising: - a first electrical machine (16) having a first rotor (20); - a second electrical machine (18) having a second rotor (22); - a planetary gear (42) having a first shaft (W1), a second shaft (W2), a third shaft (W3), a fourth shaft (W4) and a fifth shaft (W5); - a first vehicle wheel (12); - a second vehicle wheel (14), wherein, with regard to a torque flow emanating from the electric machines (16, 18) and extending towards the vehicle wheels (12, 14), the electric machines (16, 18) are arranged upstream of the planetary gear (42) in the torque flow, which is arranged upstream of the vehicle wheels (12, 14) in the torque flow; - a first switching element (S1) which is designed to couple the second rotor (22) to the first shaft (W1) in such a way that torques which can be provided by the second electric machine (18) via the second rotor (22) can be introduced into the planetary gear (42) on the first shaft (W1); and - a second switching element (S2) designed as a power-shiftable switching element, which is designed to connect the third shaft (W3) to a sixth shaft (W6) in a rotationally fixed manner; characterized by - a third switching element (S3) designed as a positive coupling, which is designed to connect the second shaft (W2) or the fourth shaft (W4) to the sixth shaft (W6) of the drive train (10) in a rotationally fixed manner; - a first gear ratio (46) which, with respect to the torque flow, is arranged downstream of the planetary gear (42) and upstream of the first vehicle wheel (12), wherein the fourth shaft (W4) is coupled or can be coupled to the first vehicle wheel (12) via the first gear ratio (46); and - a second gear ratio (48) which, with regard to the torque flow, is arranged downstream of the planetary gear (42) and upstream of the second vehicle wheel (14), wherein the fifth shaft (W5) is coupled or can be coupled to the second vehicle wheel (14) via the second gear ratio (48), and wherein a first gear ratio of the first gear ratio (46) is not equal to a second gear ratio of the second gear ratio (48). [2] Electric drive train (10) according to claim 1, characterized byin that the planetary gear (42) has a first planetary gear set (50) and a second planetary gear set (58), wherein a first planet carrier (54) of the first planetary gear set (50) and a second planet carrier (62) of the second planetary gear set (58) are connected to one another in a rotationally fixed manner and form a common planet carrier (63), wherein one of the five shafts (W1, W2, W3, W4, W5) of the planetary gear (42) has the common planet carrier (63). [3] Electric drive train (10) according to claim 2, characterized by in that the first shaft (W1) has one of sun gears (52, 60, 90) of the planetary gear (42), wherein the third shaft (W3) has another of the sun gears (52, 60, 90) of the planetary gear (42) or one of ring gears (56, 64, 94) of the planetary gear (42). [4] Electric drive train (10) according to claim 3, characterized bythat the sixth shaft (W6) is coupled or can be coupled to the first rotor (20) and, with regard to the torque flow, is arranged in the torque flow between the first rotor (20) and the planetary gear (42). [5] Electric drive train (10) according to claim 4, characterized by , that: - the first shaft (W1) has a first of the sun gears (52, 60, 90); - the third shaft (W3) has a second of the sun gears (52, 60, 90); - the second shaft (W2) has the common planet carrier (63); - the fifth shaft (W5) has a first of the ring gears (56, 64, 94) of the planetary gear (42); and - the fourth shaft (W4) has a second of the ring gears (56, 64, 94) of the planetary gear (42). [6] Electric drive train (10) according to claim 5, characterized by , that: - first planetary gears (P1), second planetary gears (P2) and third planetary gears (P3) of the planetary gear (42) are rotatably mounted on the common planetary carrier (63); - the first planetary gears (P1) mesh with the first sun gear (52) and with the second planetary gears (P2); - the second planetary gears (P2) mesh with the first ring gear (56) and with the second sun gear (60); and - the third planetary gears (P3) mesh with the second planetary gears (P2) and with the second ring gear (64). [7] Electric drive train (10) according to one of claims 4 to 6, characterized by that the sixth shaft (W6) is connected in a rotationally fixed manner to the first rotor (20). [8] Electric drive train (10) according to claim 3, characterized bythat the sixth shaft (W6) is connected in a rotationally fixed manner to a first input shaft (86) of the first transmission stage (46) and is arranged downstream of the planetary gear (42) with regard to the torque flow in the torque flow. [9] Electric drive train (10) according to claim 8, characterized by , that: - the first shaft (W1) has a first of the sun gears (52, 60, 90) of the planetary gear (42); - the second shaft (W2) has a first of the ring gears (56, 64, 94) of the planetary gear (42); - the third shaft (W3) has a second of the ring gears (56, 64, 94) of the planetary gear (42); - the fourth shaft (W4) comprises a second of the sun gears (52, 60, 90) of the planetary gear (42); and - the fifth shaft (W5) has the common planet carrier (63). [10] Electric drive train (10) according to claim 9, characterized by , that: - first planetary gears (P1), second planetary gears (P2) and third planetary gears (P3) are rotatably mounted on the common planetary carrier (63); - the first planetary gears (P1) mesh with the first sun gear (52) and with the first ring gear (56); - the second planetary gears (P2) mesh with the second sun gear (60) and with the first planetary gears (P1); and - the third planetary gears (P3) mesh with the second planetary gears (P2) and with the second ring gear (64). [11] Electric drive train (10) according to claim 2, characterized by , that Gear ratios within the first planetary gear set (50) and within the second planetary gear set (58) are selected such that, starting from the first electric machine (16) via a first torque transmission path to the first vehicle wheel (12), the same torque results at the first vehicle wheel (12) as at the second vehicle wheel (14) via a second torque transmission path to the second vehicle wheel (14), wherein the first torque transmission path extends from the first electric machine (16), further via the sixth shaft (W6), further via the second shaft (W2), further via the fourth shaft (W4), further via the first gear stage (46) to the first vehicle wheel (12), wherein the second torque transmission path runs from the first electric machine (16), further via the sixth shaft (W6), further via the second shaft (W2), further via the fifth shaft (W5), further via the second gear stage (48) to the second vehicle wheel (14).

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