Electric drive system for a motor vehicle and motor vehicle

Abstract

Electric drive system (10) for a motor vehicle, comprising: - a first electrical machine (20) having a first rotor (22); - a second electrical machine (28) having a second rotor (30); - a differential gear (40) having a sum shaft (42), a first differential shaft (44) and a second differential shaft (46); - a first intermediate shaft (48); - a second intermediate shaft (50); - a first output shaft (52); - a second output shaft (54), - a first spur gear pair (SP1) which has a first gear (Z1) connected in a rotationally fixed manner to the first differential shaft (44) and a second gear (Z2) which meshes with the first gear (Z1) and is connected in a rotationally fixed manner to the first intermediate shaft (48); - a second spur gear pair (SP2) which has a third gear (Z3) connected in a rotationally fixed manner to the second differential shaft (46) and a fourth gear (Z4) which meshes with the third gear (Z3) and is connected in a rotationally fixed manner to the second intermediate shaft (50); - a third spur gear pair (SP3) comprising a fifth gear (Z5) connected in a rotationally fixed manner to the first intermediate shaft (48) and a sixth gear (Z6) meshing with the fifth gear (Z5) and connected in a rotationally fixed manner to the first output shaft (52); and - a fourth spur gear pair (SP4), which has a seventh gear (Z7) connected in a rotationally fixed manner to the second intermediate shaft (50) and an eighth gear (Z8) meshing with the seventh gear (Z7) and connected in a rotationally fixed manner to the second output shaft (54); wherein: ◯ the first rotor (22), the second rotor (30), the sum shaft (42), the first difference shaft (44) and the second difference shaft (46) are arranged coaxially to a drive axis (AA) of the electric drive system (10) defining an axial direction of the electric drive system (10); ◯ the first intermediate shaft (48) and the second intermediate shaft (50) are arranged parallel and offset relative to the drive axis (AA); and ◯ the output shafts (52, 54) are arranged parallel and axially offset both to the drive axis (AA) and to the first intermediate shaft (48) and to the second intermediate shaft (50), characterized in that with regard to the axial direction, the first rotor (22), the first spur gear pair (SP1), the second spur gear pair (SP2), the fourth spur gear pair (SP4), the third spur gear pair (SP3) and the second rotor (30) are arranged one after the other in the following order: the first rotor (22) - the first spur gear pair (SP1) - the second spur gear pair (SP2) - the fourth spur gear pair (SP4) - the third spur gear pair (SP3) - the second rotor (30).

Description

[0001] The invention relates to an electric drive system for a motor vehicle, in particular for a motor vehicle, according to the preamble of patent claim 1. Furthermore, the invention relates to a motor vehicle with at least one such electric drive system.

[0002] DE 10 2021 133 268 A1 discloses an electric drive of a vehicle, which consists of two electric traction machines arranged axially next to each other in series.

[0003] DE 10 2022 204 752 A1 discloses an electric drive system for a motor vehicle with two electric motors whose drive torques can be transmitted to the vehicle wheels via a differential gear. US 10 927 934 B2 also discloses a system with two electric motors and a differential gear, wherein a first rotor of the first electric motor can be coupled to a differential shaft of the differential gear by means of a first switching element, and the first rotor can be coupled to a master shaft of the differential gear by means of a second switching element.

[0004] US 2018 / 0 209 526 A1 shows an electric drive system with an electric machine and a differential gear, which has a sum shaft designed as a double planet carrier and two differential shafts each designed as ring gears.

[0005] The generic US 11 192 436 B1 shows an electric drive system with two electric machines, the two rotors of which are coupled to each other via a differential gear only for the purpose of installing a parking lock, wherein each of the two rotors is coupled to a vehicle wheel via two spur gear stages.

[0006] The object of the present invention is to provide an electric drive system for a motor vehicle and a motor vehicle with at least one such electric drive system, so that a particularly compact design can be realized.

[0007] This object is achieved by an electric drive system having the features of patent claim 1 and by a motor vehicle having the features of patent claim 10. Advantageous embodiments with expedient further developments of the invention are specified in the remaining claims.

[0008] A first aspect of the invention relates to an electric drive system, also referred to as an electric drive device or electric drive apparatus, for a motor vehicle, also simply referred to as a vehicle, which is preferably designed as a motor vehicle, in particular as a passenger car. This means that the motor vehicle, in its fully manufactured state, has the electric drive system and can be driven, in particular purely electrically, by means of the electric drive system. The electric drive system has a first electric machine, which has a first rotor. In particular, the first electric machine has a first stator, by means of which the first rotor can be driven and is thus rotatable about a first machine axis of rotation relative to the first stator. The electric drive system also has a second electric machine, which has a second rotor.The second electric machine preferably has a second stator, by means of which the second rotor can be driven and is thus rotatable about a second machine axis of rotation relative to the second stator. In particular, the first electric machine can provide first drive torques for driving the motor vehicle, in particular purely electrically, via its first rotor. Furthermore, the second electric machine in particular can provide second drive torques for driving the motor vehicle, in particular purely electrically, via its second rotor. The electric drive system also has a differential gear, which is also referred to as a differential. The differential gear has a sum shaft, a first differential shaft and a second differential shaft.The sum shaft is also referred to as the first shaft, the first differential shaft as the second shaft, and the second differential shaft as the third shaft, wherein the first shaft, the second shaft, and the third shaft are shafts of the differential gear. The electric drive system also has a first intermediate shaft, which is also referred to as the fourth shaft. The electric drive system also has a second intermediate shaft, which is also referred to as the fifth shaft. The electric drive system also has a first output shaft, which is also referred to as the sixth shaft. Furthermore, the electric drive system has a second output shaft, which is also referred to as the seventh shaft. Very particularly, the electric drive system has a housing, wherein the respective rotor is rotatable about the respective machine axis of rotation relative to the housing.For example, the electric machine and / or the second electric machine and / or at least one of the shafts is at least partially arranged in the housing.

[0009] Furthermore, the electric drive system comprises, in a manner known per se, a first spur gear pair, a second spur gear pair, a third spur gear pair, and a fourth spur gear pair. The first spur gear pair comprises a first gear, which is in particular permanently and non-rotatably connected to the first differential shaft, and a second gear meshing with the first gear and, in particular permanently and non-rotatably connected to the first intermediate shaft. The second spur gear pair comprises a third gear, which is in particular permanently and non-rotatably connected to the second differential shaft, and a fourth gear meshing with the third gear and, in particular permanently and non-rotatably connected to the second intermediate shaft.The third spur gear pair comprises a fifth gear, in particular permanently connected to the first intermediate shaft in a rotationally fixed manner, and a sixth gear meshing with the fifth gear and, in particular permanently connected to the first output shaft in a rotationally fixed manner. The fourth spur gear pair comprises a seventh gear, in particular permanently connected to the second intermediate shaft in a rotationally fixed manner, and an eighth gear meshing with the seventh gear and, in particular permanently connected to the second output shaft in a rotationally fixed manner. In particular, each gear is a respective spur gear.

[0010] In the electric drive system, the first rotor, the second rotor, the sum shaft, the first differential shaft, and the second differential shaft are all arranged coaxially with a drive axis of the electric drive system, which defines an axial direction of the electric drive system, so that the first rotor, the second rotor, the sum shaft, the first differential shaft, and the second differential shaft are all arranged coaxially with one another. Thus, the machine rotational axes coincide, and the respective machine rotational axis coincides with the drive axis. The drive axis coincides with the axial direction of the electric drive system. In other words, the axial direction of the electric drive system, whose radial direction is perpendicular to the axial direction of the electric drive system, runs along the drive axis.In particular, the drive axis is an imaginary axis that runs along a first straight line or coincides with the first straight line. For example, the drive axis is a first axis of rotation, or the drive axis coincides with a first axis of rotation, with the first axis of rotation also being referred to as the main axis of rotation. Thus, the respective rotor is rotatable about the drive axis, thus about the main axis of rotation, relative to the housing and relative to the respective stator.

[0011] In the electric drive system, the first intermediate shaft and the second intermediate shaft are arranged parallel and offset from the drive axle.

[0012] Since the respective rotor can rotate about the drive axis relative to the housing and relative to the respective stator, the drive axis is also referred to as the drive rotation axis.

[0013] In order to be able to realize a particularly compact and cost-effective design of the electric drive system, it is provided in a manner known per se that the output shafts are arranged parallel to and axially offset from both the drive axis and the first intermediate shaft and also from the second intermediate shaft. In particular, the first output shaft is rotatable about a first shaft axis of rotation relative to the housing and relative to the respective stator, and preferably the second output shaft is rotatable about a second shaft axis of rotation relative to the housing and relative to the respective stator. The respective shaft axis of rotation is arranged parallel to and axially offset from both the drive axis and the intermediate shaft axis, such that the respective shaft axis of rotation runs parallel to the drive axis and parallel to the intermediate shaft axis and is spaced from both the drive axis and the intermediate shaft axis.The output shafts are very preferably arranged coaxially to an output shaft axis which is arranged parallel and offset in axis to both the drive axis and the intermediate shaft axis, so that the output shafts are very preferably arranged coaxially to one another. Thus, the respective shaft axis of rotation preferably coincides with the output shaft axis, about which the respective output shaft can then be rotated relative to the housing and relative to the respective stator. Thus, the output shaft axis is also referred to as the drive shaft axis of rotation. The output shaft axis is a third axis of rotation or coincides with a third axis of rotation, wherein preferably the respective output shaft can be rotated about the third axis of rotation relative to the housing and relative to the respective stator. Preferably, the output shaft axis runs along a third straight line or the output shaft axis coincides with a third straight line.

[0014] The output shaft axis is spaced apart from both the drive axis and the intermediate shaft axis, with the output shaft axis running parallel to the drive axis and parallel to the intermediate shaft axis. The intermediate shaft axis is preferably an imaginary axis, and very preferably the output shaft axis and / or the respective shaft rotation axis is a respective imaginary axis. Thus, it is very preferably provided that the aforementioned rotation axes are spaced apart from one another in pairs and run parallel to one another. Furthermore, the invention can realize a particularly advantageous and high level of functionality, and this in a space-saving and cost-effective manner.

[0015] According to the invention, with regard to the axial direction of the electric drive system, thus in the axial direction of the electric drive system and thus viewed along the main axis of rotation, the first rotor, the first spur gear pair, the second spur gear pair, the fourth spur gear pair, the third spur gear pair and the second rotor are arranged in the order mentioned, i.e. in the order in which they are named, one after the other, i.e. consecutively.In other words, it is preferably provided that, with regard to the axial direction, i.e. along the main axis of rotation of the electric drive system, the first rotor, the first spur gear pair, the second spur gear pair, the fourth spur gear pair, the third spur gear pair, and the second rotor are arranged consecutively, i.e. one after the other, in the following order: the first rotor - the first spur gear pair - the second spur gear pair - the fourth spur gear pair - the third spur gear pair - the second rotor. Thus, in the axial direction of the electric drive system, the first spur gear pair is preferably connected to the first rotor, the second spur gear pair is connected to the first spur gear pair, the fourth spur gear pair is connected to the second spur gear pair, the third spur gear pair is connected to the fourth spur gear pair, and the second rotor is connected to the third spur gear pair.This allows the electric drive system to have a particularly small installation space requirement.

[0016] Particularly advantageously, the first intermediate shaft and the second intermediate shaft are arranged coaxially to an intermediate shaft axis of the electric drive system, which is arranged parallel to and offset from the drive axis. The first intermediate shaft and the second intermediate shaft are thus arranged coaxially to one another. The intermediate shaft axis is an imaginary second axis. In particular, the intermediate shaft axis is a second axis of rotation or the intermediate shaft axis coincides with a second axis of rotation. Very particularly, the intermediate shaft axis runs along a second straight line or the intermediate shaft axis coincides with a second straight line. The feature that the intermediate shaft axis is arranged parallel to and offset from the drive axis is to be understood as meaning that the intermediate shaft axis runs parallel to the drive axis and is spaced from the drive axis.The respective intermediate shaft is rotatable about the intermediate shaft axis relative to the housing, so that the intermediate shaft axis is also referred to as the intermediate shaft rotation axis.

[0017] In order to be able to realize a particularly advantageous functionality in a particularly space-efficient manner, one embodiment of the invention provides that the first rotor is coupled or can be coupled to the first differential shaft, bypassing the sum shaft and the second differential shaft, in particular in a torque-transmitting manner. Furthermore, it is provided that the second rotor is coupled or can be coupled to the second differential shaft, bypassing the sum shaft and the first differential shaft, in particular in a torque-transmitting manner.The feature that the first rotor is or can be coupled to the first differential shaft, bypassing the sum shaft and bypassing the second differential shaft, is to be understood in particular as the following: With respect to a first torque flow, along which the respective first drive torque is transferable from the first rotor to the first differential shaft or is transferred during operation of the drive system, neither the sum shaft nor the second differential shaft is arranged downstream of the first rotor and upstream of the first differential shaft in the first torque flow, so that the respective first drive torque on its way from the first rotor to the first differential shaft neither flows or flows via the sum shaft nor via the second differential shaft from the first rotor to the first differential shaft.Accordingly, the feature that the second rotor is or can be coupled to the second differential shaft, bypassing the sum shaft and bypassing the first differential shaft, is to be understood as follows: With respect to a second torque flow, along which the respective second drive torque can be transmitted from the second rotor to the second differential shaft or is transmitted during the aforementioned operation or a further operation of the drive system, neither the sum shaft nor the first differential shaft is arranged downstream of the second rotor and upstream of the second differential shaft in the second torque flow, so that the respective second drive torque on its way from the second rotor to the second differential shaft neither flows or flows via the sum shaft nor via the first differential shaft from the second rotor to the second differential shaft.

[0018] Preferably, the respective electrical machine is a respective high-voltage component whose respective 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.

[0019] In its fully manufactured state, the motor vehicle very preferably has at least one vehicle axle. In its fully manufactured state, the motor vehicle very preferably has at least or exactly two vehicle axles, namely the aforementioned vehicle axle as the first vehicle axle and a second vehicle axle. Each vehicle axle has at least or exactly two vehicle wheels, wherein the vehicle wheels of each vehicle axle are preferably arranged on opposite sides of the motor vehicle in the transverse direction of the motor vehicle. The vehicle wheels 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 on the ground in the vertical direction of the motor vehicle via the ground contact elements, the ground contact elements roll, in particular directly, on the ground. In this case, one of the vehicle axles, for example, has the electric drive system. When reference is made below to the vehicle axle, this means, unless otherwise stated, the vehicle axle having the electric drive system. The vehicle wheels of the vehicle axle can be driven by means of the electric drive system, in particular purely electrically. When reference is made below to the vehicle wheels, this means, unless otherwise stated, the vehicle wheels of the vehicle axle having the electric drive system.A first of the vehicle wheels can be driven by the first electric machine, i.e., by the first rotor, so that the first vehicle wheel can be driven by the respective first drive torque. A second of the vehicle wheels of the vehicle axle having the electric drive system can be driven by the second electric machine, i.e., by the second rotor, so that the second vehicle wheel can be driven by the respective second drive torque. In particular, it is provided that the first vehicle wheel can be driven by the first electric machine, i.e., by the first rotor, bypassing the second vehicle wheel.This means that, with respect to a third torque flow along which the respective first drive torque can be transmitted from the first rotor to the first vehicle wheel in order to thereby drive the first vehicle wheel, the second vehicle wheel is not arranged downstream of the first rotor and upstream of the first vehicle wheel in the third torque flow.

[0020] Furthermore, it is preferably provided that the second vehicle wheel can be driven by means of the second rotor, bypassing the first vehicle wheel. This means that, with regard to a fourth torque flow along which the respective second drive torque can be transmitted from the second rotor to the second vehicle wheel in order to thereby drive the second vehicle wheel, the first vehicle wheel is not arranged downstream of the second rotor and upstream of the second vehicle wheel in the fourth torque flow. Thus, the respective first drive torque does not flow from the first rotor to the first vehicle wheel via the second vehicle wheel on its way from the first rotor to the first vehicle wheel, and accordingly, the respective second drive torque does not flow from the second rotor to the second vehicle wheel via the first vehicle wheel on its way from the second rotor to the second vehicle wheel.This allows for a particularly advantageous drive system for the motor vehicle. The first torque flow can, for example, be a component of the third torque flow. The second torque flow can, for example, be a component of the fourth torque flow.

[0021] When reference is made above and below to the axial direction, this means, unless otherwise stated, the axial direction of the electric drive system. When reference is made above and below to the radial direction, this means, unless otherwise stated, the radial direction of the electric drive system. In the context of the present disclosure, the feature “radially overlapping” is to be understood as follows: Two elements, in particular at least substantially rotationally symmetrical, are arranged radially, in particular with respect to one another, overlapping, in particular with respect to a common axis running, for example, in the radial direction of the drive system and / or in the radial direction of the drive system, if they are each arranged at least partially in a region of the same radial coordinates, in particular the same angular coordinates.The term "radial" refers to the radial direction of the electric drive system. In other words, the term "radial" refers to the radial direction of the electric drive system.

[0022] The feature “axially overlapping” is to be understood as follows: Two elements are arranged axially overlapping, in particular with respect to one another, with respect to a common axis running in particular in the axial direction of the electric drive system and / or in the axial direction of the electric drive system, if they are each arranged at least partially in a region of the same axial coordinates. In the context of the present disclosure, the term “axial” is to be understood as the axial direction of the electric drive system. In other words, the term “axial” means the axial direction of the electric drive system. In other words, “axial” refers to the axial direction of the electric drive system, and “radial” refers to the radial direction of the electric drive system.

[0023] In the context of the present disclosure, the feature that a first component is arranged radially within a second component is to be understood as meaning that the first component is arranged in a region of smaller radii than the second component, in particular with respect to the main axis of rotation. Furthermore, the feature that a first component is arranged axially within a second component is to be understood as meaning that in the installed position of the electric drive system, which assumes its installed position in the fully manufactured state of the motor vehicle having the electric drive system, and in particular with respect to straight-ahead travel of the motor vehicle, that is to say in particular when a steering system of the motor vehicle is set to cause the motor vehicle to travel straight ahead, the first component, which is arranged axially within the second component,is arranged on one side of the second component towards a centre of the motor vehicle, also referred to as the vehicle centre, thus the first component is arranged on a side of the second component pointing towards the centre of the motor vehicle, so that the first component is arranged further inwards, i.e. closer to the centre of the motor vehicle, than the second component, particularly when viewed in the transverse direction of the motor vehicle.

[0024] In the context of the present disclosure, the feature that two components, such as the first differential shaft and the first gear, 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 a component rotation axis common to the components, such as the main rotation axis, at the same angular velocity, in particular relative to a reference element, such as the housing. In other words, two elements are connected to one another in a rotationally fixed manner if they are arranged coaxially to one another, in particular with respect to their component rotation axis or with respect to a rotational symmetry axis, and if they are connected to one another in such a way that they always rotate at the same angular velocity.An element is connected to the housing in a rotationally fixed manner if it cannot be rotated relative to the housing.

[0025] The feature that two components are connected or coupled to one another in a torque-transmitting manner means that the components are coupled or connected to one another in such a way that torques can be transmitted between the components. If the components are connected or coupled to one another in a rotationally fixed manner, the components are also connected or coupled to one another in a torque-transmitting manner. Two components connected to one another in a torque-transmitting manner can thus be connected to one another in a rotationally fixed manner. Furthermore, it is conceivable that two components connected to one another in a torque-transmitting manner are connected to one another in a torque-transmitting manner via an intermediate transmission unit, so that two torques can be transmitted between the components via the transmission unit, while the components are connected to one another in a torque-transmitting manner, although the components can be rotatable relative to one another.For example, such a transmission unit is the respective spur gear stage.

[0026] The feature that two components are permanently connected or coupled to one another in a torque-transmitting manner does not mean that a switching element is provided that can be switched between a coupling state that connects or couples 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 and therefore permanently torque-transmitting, i.e., connected or coupled to one another in such a way that torque can be transmitted between the components. Thus, for example, one of the components can be driven by the respective other component, or vice versa.

[0027] In particular, the feature that two components are permanently connected or coupled 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 that connects or couples the components to one another in a rotationally fixed manner and a decoupling state in which the components are decoupled from one another and rotatable relative to one another, so that no torque can be transmitted between the components via the switching element. Instead, the components are always connected or coupled to one another, thus permanently connected or coupled to one another in a rotationally fixed manner. Furthermore, the feature that two components can be connected or coupled to one another in a rotationally fixed manner is to be understood as meaning that the components are assigned a switching element which can be switched between at least one coupling state and at least one decoupling state.In the coupled state, the components are connected or coupled to one another in a rotationally fixed 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 about the component rotation axis. The same applies to the feature that two components can be connected or coupled to one another in a torque-transmitting manner. Thus, for example, the feature that two components can be connected or coupled to one another in a torque-transmitting manner is to be understood as meaning that a switching element is assigned to the components, wherein the switching element can be switched between at least one connected state and at least one released state. In the connected state, the components are coupled or connected to one another in a torque-transmitting manner by means of the switching element such that torques can be transmitted between the components, in particular via the switching element.In the release state, the components are decoupled from each other, so that in the release state no torque can be transmitted between the components via the switching element.

[0028] The feature that two elements are formed in one piece with each other is to be understood as meaning that the elements are not formed separately from each other and connected to each other, but the elements are formed from a single piece and thus integrally, i.e. formed in one piece, so that the elements are formed by a body which is formed in one piece, thus formed from a single piece and thus integrally manufactured, which is designed as a monoblock.

[0029] In order to keep the length of the electric drive system, also referred to as the axial length, particularly small, viewed along the main axis of rotation, and thus to be able to represent a particularly compact design, a further embodiment of the invention provides that the third spur gear pair and / or the fourth spur gear pair are arranged axially overlapping the differential gear.

[0030] In order to be able to realize particularly advantageous functionality in a particularly compact design, one embodiment provides a first switching element which is designed to couple, i.e., connect, the first rotor to the first differential shaft in a torque-transmitting, in particular rotationally fixed, manner. Preferably, a second switching element is provided which is designed to couple, i.e., connect, the first rotor to the sum shaft in a torque-transmitting, in particular rotationally fixed, manner. In other words, the first rotor can be coupled or connected to the first differential shaft in a torque-transmitting, in particular rotationally fixed, manner by means of the first switching element.In addition, the first rotor can preferably be coupled, i.e. connected, to the sum shaft in a torque-transmitting, in particular rotationally fixed, manner by means of the second switching element. This means, for example, that the first switching element can be switched between a first coupling state and a first decoupling state. In the first coupling state, the first rotor and the first differential shaft are connected to one another in a torque-transmitting, in particular rotationally fixed, manner by means of the first switching element. In the first decoupling state, the first rotor and the first differential shaft are decoupled from one another, such that no torque can be transmitted between the first rotor and the first differential shaft via the first switching element. Accordingly, the second switching element can preferably be switched between a second coupling state and a second decoupling state.In the second coupling state, the first rotor and the sum shaft are connected to each other in a torque-transmitting, in particular rotationally fixed, manner by means of the second switching element. In the second decoupling state, the first rotor and the sum shaft are decoupled from each other, so that no torque can be transmitted between the first rotor and the sum shaft via the second switching element.

[0031] In the context of the present disclosure, ordinals also referred to as ordinal numbers, such as “first”, “first”, “first”, “second”, “second”, “second” etc., not only necessarily indicate a set of elements to which the ordinal numbers refer, but in the context of the present disclosure, ordinal numbers, and thus ordinals, are used in particular in order to be able to refer unambiguously and consistently to the elements to which the ordinals refer.

[0032] In a further, very advantageous embodiment of the invention, the electric drive system has a third switching element which is designed to couple the second rotor to the second differential shaft in a torque-transmitting, in particular rotationally fixed, manner. This makes it possible to create a particularly advantageous drive in a particularly space-efficient manner. In other words, the third switching element can be used to couple, i.e. connect, the second rotor and the second differential shaft to one another in a torque-transmitting, in particular rotationally fixed, manner. Thus, for example, the third switching element can be switched between a third coupling state and a third decoupling state. In the third coupling state, the second rotor and the second differential shaft are connected to one another in a torque-transmitting, in particular rotationally fixed, manner by means of the third switching element.In the third decoupling state, the second rotor and the second differential shaft are decoupled from each other, so that no torque can be transmitted between the second rotor and the second differential shaft via the third switching element.

[0033] Preferably, it is provided that the second switching element is in the second decoupling state when, and preferably always when, the first switching element is in the first coupling state. Preferably, it is provided that the first switching element is in the first decoupling state when, and preferably always when, the second switching element is in the second coupling state.

[0034] In order to be able to realize a particularly small installation space requirement, that is to say in particular a particularly small axial length, of the electric drive system, in particular in the axial direction of the electric drive system, it is provided in a further embodiment of the invention that the first switching element is arranged axially between the first rotor and the differential gear.

[0035] A further embodiment is characterized by a fourth shifting element which is designed, in particular precisely, to non-positively connect two of the three shafts of the differential gear to one another. In other words, by means of the fourth shifting element, in particular precisely, two of the three shafts of the differential gear can be non-positively connected to one another. This allows a particularly advantageous drive to be realized in a particularly space-saving manner. The shafts of the differential gear which can be non-positively connected to one another by means of the fourth shifting element are also referred to as differential gear shafts. By means of the fourth shifting element, for example, a differential lock can be realized in a space-saving and cost-effective manner. This is explained in more detail below. The fourth shifting element can be switched, for example, between a fourth coupling state and a fourth decoupling state.In the fourth coupling state, the differential gear shafts are non-positively connected to one another by means of the fourth shifting element. In the fourth decoupling state, the differential gear shafts are decoupled from one another and rotatable relative to one another, so that no torque can be transmitted between the differential gear shafts via the fourth shifting element. If the fourth shifting element is in its fourth coupling state, the differential lock is engaged, i.e., activated. If the fourth shifting element is in its fourth decoupling state, the differential lock is deactivated, i.e., switched off or disengaged.If the differential lock is activated, i.e., engaged or switched on, this prevents, for example, different speeds of the vehicle wheels on the vehicle axle with the electric drive system, or only permits slightly different speeds. If the differential lock is, for example, disengaged, i.e., deactivated, this permits, for example, different speeds of the vehicle wheels, so that, for example, when the vehicle is cornering, the vehicle wheels can rotate at different speeds, in particular such that the vehicle wheel on the outside of the curve rotates or can rotate at a higher speed than the vehicle wheel on the inside of the curve.

[0036] In order to keep the installation space requirement of the electric drive system particularly low and thus to be able to realize a particularly compact design, it is provided in a further embodiment of the invention that the sum shaft is designed as a double planet carrier, wherein the first differential shaft is designed as a first ring gear, and wherein the second differential shaft is designed as a second ring gear.

[0037] Finally, in order to achieve a particularly high level of functionality in a particularly space-saving manner, it has proven particularly advantageous if the electric drive system has a parking lock by means of which the master shaft can be connected in a rotationally fixed manner to the housing of the electric drive system, bypassing the differential shafts. The parking lock can thus be switched, for example, between a locked state and a released state. In the locked state, the master shaft is connected in a rotationally fixed manner to the housing by means of the parking lock, in particular in a form-fitting manner, bypassing the differential shaft. In the released state, the parking lock permits rotations of the master shaft about the main axis of rotation, i.e. about the drive axis and relative to the housing, so that in the released state the master shaft can rotate about the main axis of rotation relative to the housing. In the locked state, the parking lock is activated, i.e. switched on or engaged.In the release state, the parking lock is disengaged, meaning deactivated or switched off. If the parking lock is activated, the vehicle wheels, for example, are secured against rotation relative to the housing, in particular, they are connected to the housing in a rotationally fixed manner. If the parking lock is disengaged, meaning in the release state, the respective vehicle wheel can rotate relative to the housing. Thus, in the locked state of the parking lock or by the locked state of the parking lock, the motor vehicle can be secured against unwanted rolling away, particularly if the motor vehicle is parked on a slope.The invention enables a particularly compact and advantageous arrangement and / or connection of the parking lock, which is particularly advantageous given that the electric machines, which are designed in particular as axially parallel drive units, can drive the vehicle wheels independently of one another, meaning that the first vehicle wheel can be driven by means of the first electric machine, bypassing the second vehicle wheel, and the second vehicle wheel can be driven by means of the second electric machine, bypassing the first vehicle wheel. In particular, the parking lock can be designed and arranged as a central parking lock. By means of the precisely one parking lock, in particular, the master shaft and, via this, the vehicle wheels can be secured against rotation relative to the housing, whereby the motor vehicle can be secured in a particularly advantageous manner against undesired rolling away.

[0038] The parking lock has, for example, a first locking element that is connected, in particular permanently, in a rotationally fixed manner to the master shaft and which is, for example, a first parking lock gear. Furthermore, the parking lock has, for example, a second locking element that is designed, for example, as a claw or pawl. In particular, the pawl is also referred to as a locking pawl. The second locking element is movable relative to the housing between at least one locking position and at least one release position. The locking position moves the locking state, and the release position moves the release state. In other words, in the locking position, the second locking element interacts, in particular in a form-fitting manner, with the first locking element, whereby the master shaft is connected in a rotationally fixed manner to the housing.In the stated embodiment, there is no interaction between the second locking element and the first locking element in such a way that the summing shaft is connected to the housing in a rotationally fixed manner, so that in the release position the second locking element releases the first locking element and thus the summing shaft for rotation relative to the housing and about the main axis of rotation. Thus, in the release position, the summing shaft can rotate about the main axis of rotation relative to the housing. Preferably, one, in particular a single, actuator is provided, which is also referred to as a central actuator, wherein the second locking element can be moved relative to the housing between the locked position and the released position by means of the actuator. The parking lock can therefore be implemented with only a small number of parts and is therefore particularly space-saving, cost-effective and weight-effective.

[0039] A second aspect of the invention relates to a motor vehicle, also referred to simply as a vehicle, and preferably designed as a motor vehicle, in particular as a passenger car, which has at least one electric drive system according to the first aspect of the invention and can be driven by the electric drive system, in particular purely electrically. Advantages and advantageous embodiments of the first aspect of the invention are to be regarded as advantages and advantageous embodiments of the second aspect of the invention, and vice versa.

[0040] 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 alone in the figures, 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.

[0041] The drawing shows: Fig. 1 is a schematic representation of a first embodiment of an electric drive system for a motor vehicle; Fig. 2 is a schematic representation of a second embodiment of the electric drive system not falling under claim 1; Fig. 3 shows a partial schematic representation of a third embodiment of the electric drive system not falling under claim 1; Fig. 4 is a schematic representation of a fourth embodiment of the electric drive system not falling under claim 1; and Fig. 5 shows a partial schematic representation of a fifth embodiment of the electric drive system not falling under claim 1.

[0042] In the figures, identical or functionally identical elements are provided with the same reference symbols.

[0043] Fig. 1 shows a schematic representation of a first embodiment of an electric drive system 10 for a motor vehicle. The motor vehicle, also simply referred to as a vehicle and preferably designed as a motor vehicle, in particular as a passenger car, has, in its fully manufactured state, the electric drive system 10 and at least or exactly two vehicle axles arranged consecutively and thus one behind the other in the longitudinal direction of the motor vehicle, namely a first vehicle axle and a second vehicle axle. For example, the electric drive system 10 is a component of the first vehicle axle. The respective vehicle axle has at least or exactly two respective vehicle wheels. The first vehicle axle is in Fig. 1 is shown particularly schematically and designated 12. The vehicle wheels of the vehicle axle 12 are in Fig. 1 and designated 14 and 16. 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 transverse direction of the motor vehicle is illustrated by a double arrow 18. The vehicle wheel 14 is also referred to as the first vehicle wheel, and the vehicle wheel 16 is also referred to as the second vehicle wheel.

[0044] The electric drive system 10 has a first electric machine 20, by means of which the vehicle wheel 14 can be driven, bypassing the vehicle wheel 16. For this purpose, the electric machine 20 has a first rotor 22 and a first stator 24, by means of which the rotor 22 can be driven and is thus rotatable relative to the stator 24. Via the rotor 22, the electric machine 20 can provide first drive torques for driving the vehicle wheel 14. The respective first drive torque or a respective torque resulting from the respective first drive torque for driving the vehicle wheel 14 is in Fig. 1 is illustrated by an arrow 26.

[0045] The electric drive system 10 also has a second electric machine 28, by means of which the second vehicle wheel 16 can be driven, bypassing the first vehicle wheel 14. For this purpose, the second electric machine has a second rotor 30 and a second stator 32, by means of which the rotor 30 can be driven and is thus rotatable relative to the stator 32. Via its second rotor 30, the second electric machine 28 can provide second drive torques for driving the vehicle wheel 16. The respective second drive torque or a respective torque resulting from the respective second drive torque for driving the vehicle wheel 16 is in Fig. 1 by an arrow 34. From Fig. 1 shows that the respective electrical machine 20, 28 is designed as an axial flux machine (AFM). The axial flux machine is also referred to as an axial flux motor.

[0046] The electric drive system 10 also has a housing 36, wherein the housing walls of the housing 36 are Fig. 1 are shown in dashed lines and designated 38. For example, the respective electric machine 20, 28 is each arranged at least partially in the housing 36. The respective rotor 22, 30 is rotatable relative to the housing 38.

[0047] The electric drive system 10 also has a differential gear 40, which can be arranged, for example, in the housing 36. For example, the differential gear 40 is designed to superimpose the respective first drive torque with the respective second drive torque and vice versa. In other words, for example, the respective first drive torque and the respective second drive torque can be superimposed on one another by means of the differential gear 40, so that the differential gear 40 is designed or operable, or functions, or can function, for example, as a coupling gear. In particular, it is conceivable that the rotors 22 and 30 can be coupled or are coupled to one another in a torque-transmitting manner via the differential gear 40. The differential gear 40 has a master shaft 42, a first differential shaft 44, and a second differential shaft 46.

[0048] The electric drive system 10 has a first intermediate shaft 48, a second intermediate shaft 50, a first output shaft 52 and a second output shaft 54.

[0049] Out of Fig. 1 shows that the first rotor 22, the second rotor 30, the sum shaft 42, the first differential shaft 44, and the second differential shaft 46 are all arranged coaxially to an imaginary drive axis AA of the electric drive system 10, which defines an axial direction of the electric drive system, so that the first rotor 22, the second rotor 30, the sum shaft 42, the first differential shaft 44, and the second differential shaft 46 are all arranged coaxially to one another. The rotors 22 and 30, the differential shafts 44 and 46, and the sum shaft 42 are rotatable about the drive axis AA relative to the housing 36, so that the drive axis is also referred to as the drive axis of rotation, or coincides with a main axis of rotation, or is a main axis of rotation.

[0050] The first intermediate shaft 48 and the second intermediate shaft 50 are arranged coaxially to an intermediate shaft axis ZA of the electric drive system 10, such that the intermediate shafts 48 and 50 are arranged coaxially to one another. The intermediate shaft axis ZA is arranged parallel to and axially offset from the drive axis AA, such that the intermediate shaft axis ZA runs parallel to the drive axis AA and is spaced from the drive axis AA. The intermediate shaft axis ZA is an imaginary axis, wherein the intermediate shaft axis ZA is an intermediate shaft rotation axis or coincides with an intermediate shaft rotation axis, and wherein the respective intermediate shaft 48, 50 is rotatable about the intermediate shaft rotation axis, thus about the intermediate shaft axis ZA relative to the housing 36.

[0051] In order to achieve a particularly compact design of the drive system 10, it is provided that the output shafts 52 and 54 are arranged parallel and offset relative to both the drive axis AA and the intermediate shaft axis ZA. Fig. In the first embodiment shown in Figure 1, the output shafts 52 and 54 are arranged coaxially to an output shaft axis ABA, so that the output shafts 52 and 54 are arranged coaxially to one another. The output shaft axis ABA is arranged parallel and offset both to the drive axis AA and to the intermediate shaft axis ZA. This means that the drive axis AA, the intermediate shaft axis ZA, and the output shaft axis ABA run parallel to one another in pairs and are spaced apart from one another in pairs. The drive axis AA, the intermediate shaft axis ZA, and the output shaft axis ABA are imaginary axes that run along a respective straight line or coincide with the respective straight line. The respective output shaft 52, 54 is rotatable about the output shaft axis ABA relative to the housing 36.

[0052] Furthermore, it is provided that the first rotor 22 is coupled, in particular permanently, in a rotationally fixed manner to the first differential shaft 44, bypassing the sum shaft 42 and bypassing the second differential shaft 46. Furthermore, in the first embodiment, it is provided that the second rotor 30 is coupled, in particular permanently, in a rotationally fixed manner to the second differential shaft 46, bypassing the sum shaft 42 and bypassing the first differential shaft 44.

[0053] In the first embodiment, the differential gear 40 is a planetary differential, and thus designed as a planetary differential. The sum shaft 42 is designed as a ring gear, the first differential shaft 44 as a sun gear, and the second differential shaft 46 as a planet carrier of the planetary differential. The ring gear, the planet carrier, and the sun gear are arranged coaxially to one another. The planet carrier is a double planet carrier, on which first planet gears P1 and, additionally provided, second planet gears P2 are each rotatably mounted. The respective first planet gear P1 meshes with the sun gear designated S, and the respective second planet gear P2 meshes with the ring gear designated H, whereby meshing of the respective planet gear P1 with the ring gear H is omitted, and meshing of the respective planet gear P2 with the sun gear S is omitted.In addition, overall, one of the first planetary gears P1 meshes with, in particular precisely, one of the second planetary gears P2.

[0054] The electric drive system 10 has a first spur gear pair SP1, a second spur gear pair SP2, a third spur gear pair SP3, and a fourth spur gear pair SP4. The first spur gear pair SP1 has a first gear Z1 and a second gear Z2. The gear Z1 is connected, in particular permanently, in a rotationally fixed manner to the first differential shaft 44. The second gear Z2 is connected, in particular permanently, in a rotationally fixed manner to the intermediate shaft 48, wherein the gear Z2 meshes with the gear Z1. The second spur gear pair SP2 has a third gear Z3 and a fourth gear Z4. The third gear Z3 is connected, in particular permanently, in a rotationally fixed manner to the second differential shaft 46. The fourth gear Z4 is connected, in particular permanently, in a rotationally fixed manner to the second intermediate shaft 50, wherein the fourth gear Z4 meshes with the third gear Z3. The third spur gear pair SP3 has a fifth gear Z5 and a sixth gear Z6.The fifth gear Z5 is, in particular permanently, connected in a rotationally fixed manner to the first intermediate shaft 48. The sixth gear Z6 is, in particular permanently, connected in a rotationally fixed manner to the first output shaft 52, wherein the sixth gear Z6 meshes with the fifth gear Z5. It can be seen that the first vehicle wheel 14 can be driven by means of the output shaft 52, in particular by driving the output shaft 52. Thus, the rotor 22 can drive the vehicle wheel 14 via the output shaft 52, bypassing the vehicle wheel 16. The fourth spur gear pair SP4 has a seventh gear Z7 and an eighth gear Z8. The seventh gear Z7 is, in particular permanently, connected in a rotationally fixed manner to the second intermediate shaft 50. The eighth gear Z8, in particular permanently, is connected in a rotationally fixed manner to the second output shaft 54, wherein the eighth gear Z8 meshes with the seventh gear Z7.It can be seen that the vehicle wheel 16 can be driven by means of the output shaft 54, so that the second rotor 30 can drive the vehicle wheel 16 via the output shaft 54, bypassing the vehicle wheel 14.

[0055] For example, in the first embodiment, it is provided that the second differential shaft 46 is designed as a first hollow shaft, in which the first differential shaft 44 is at least partially received. For example, the first hollow shaft is penetrated, in particular completely, by the differential shaft 44. In the Fig. 1, it is also provided that the second intermediate shaft 50 is designed as a second hollow shaft, wherein the first intermediate shaft 48 is at least partially received in the second hollow shaft. In particular, it is provided here that the intermediate shaft 48 completely penetrates the second hollow shaft. The gears Z1 and Z5 are arranged on sides of the hollow shaft 50 that face away from each other or point away from each other in the axial direction of the drive system 10, so that, viewed in the axial direction of the electric drive system 10, the gear Z2 is on this side and the gear Z5 is on the other side of the second hollow shaft, in particular permanently, connected in a rotationally fixed manner to the intermediate shaft 48.

[0056] In the first embodiment, it is provided that, with regard to the axial direction of the drive system 10 and thus the drive axis AA, the first rotor 22, the first spur gear pair SP1, the second spur gear pair SP2, the fourth spur gear pair SP4, the third spur gear pair SP3 and the second rotor 30 are arranged one after the other, that is to say consecutively, in the order mentioned.

[0057] In the first embodiment, the electric drive system 10 has a parking lock PS, by means of which the sum shaft 42 can be connected to the housing 36 in a rotationally fixed manner.

[0058] Fig. Figure 2 shows a schematic representation of a second embodiment of the electric drive system 10, not falling under claim 1. In particular, in the first embodiment, the differential gear 40 is designed as a spur gear differential. In the first embodiment, an asymmetrical stage arrangement is provided.

[0059] In contrast, in the second embodiment, which is shown in Fig. 2, a symmetrical step arrangement is provided. In the second embodiment, the differential gear 40 is designed as a planetary differential. In the second embodiment, the summing shaft 42 is also designed as a planet carrier, in particular as a double planet carrier, wherein in the second embodiment, first planet gears P1 and additionally provided second planet gears P2 are rotatably held on the planet carrier of the differential gear 40. In the second embodiment, the first differential shaft 44 is designed as a first ring gear H1 and the second differential shaft 46 is designed as a second ring gear H2, wherein the respective planet gear P2 meshes with the second ring gear H2, and wherein meshing of the respective planet gear P2 with the ring gear H1 is omitted. The respective planet gear P1 meshes with the ring gear H1, wherein meshing of the respective planet gear P1 with the ring gear H2 is omitted.Furthermore, it is provided that, in particular precisely, a respective one of the first planetary gears P1 meshes with, in particular precisely, a respective one of the second planetary gears P2. In the second embodiment, the differential gear 40 is free of a sun gear meshing with the planetary gears P1 and free of a sun gear meshing with the planetary gears P2.

[0060] In the second embodiment, with respect to the axial direction of the electric drive system 10, the first rotor 22, the first spur gear pair SP1, the third spur gear pair SP3, the fourth spur gear pair SP4, the second spur gear pair SP2, and the second rotor 30 are arranged one after the other in the stated order, i.e., consecutively. In the first embodiment, at least the fourth spur gear pair SP4 is arranged to axially overlap the differential gear 40. In the second embodiment, the spur gear pairs SP3 and SP4 are each arranged to at least partially axially overlap the differential gear 40.

[0061] In the first embodiment, the first rotor 22 is, in particular permanently, connected in a rotationally fixed manner to the differential shaft 44, and the rotor 30 is, in particular permanently, connected in a torque-transmitting manner, in particular rotationally fixed, to the differential shaft 46. In the second embodiment, a first switching element SE1 is provided, by means of which the first rotor 22 can be connected in a rotationally fixed manner to the first differential shaft 44. A second switching element SE2 is also provided, by means of which the first rotor 22 can be connected in a rotationally fixed manner to the summing shaft 42. In the present case, for example, the switching element SE1 is, in particular permanently, connected in a rotationally fixed manner to the differential shaft 44, and for example, the switching element SE2 is, in particular permanently, connected in a rotationally fixed manner to the summing shaft 42.The switching elements SE1 and SE2 are assigned a first switching element UE1, which is movable relative to the switching elements SE1 and SE2 and relative to the housing 36, in particular rotationally and / or translationally, between a first coupling position and a second coupling position. In the first coupling position, the rotor 22 and the differential shaft 44 are connected to one another in a rotationally fixed manner by means of the switching element UE1 and the switching element SE1, while a rotationally fixed connection of the rotor 22 to the summing shaft 42 via the switching element SE2 is omitted, i.e., canceled. In the second switching position, the rotor 22 and the summing shaft 42 are connected to one another in a rotationally fixed manner by means of the switching element UE1 and the switching element SE2, while a rotationally fixed connection of the rotor 22 to the differential shaft 44 via the switching element SE1 is prevented, i.e., canceled.Thus, in the first switching position, the first switching element SE1 is in a first coupled position, and in the second switching position, the switching element SE1 is in a first uncoupled state. In the second switching position, the second switching element SE2 is in a second coupled state, and in the first switching position, the second switching element SE2 is in a second uncoupled state. In the first coupled state, the rotor 22 and the differential shaft 44 are connected to one another in a rotationally fixed manner by means of the switching element SE1, and in the first uncoupled state, the rotor 22 and the differential shaft 44 are decoupled from one another in such a way that the rotor 22 and the differential shaft 44 can rotate relative to one another about the drive axis AA and no torque can be transmitted between the differential shaft 44 and the rotor 22 via the switching element SE1.In the second coupling state, the rotor 22 and the summing shaft 45 are connected to one another in a rotationally fixed manner by means of the second switching element SE2. In the second decoupling state, the rotor 22 and the summing shaft 42 are decoupled from one another such that the rotor 22 and the summing shaft 42 are rotatable relative to one another about the drive axis AA, and so no torque can be transmitted between the rotor 22 and the summing shaft 42 via the switching element SE2.For example, the switching elements SE1 and SE2 and the switching element UE1 are positive-locking switching elements, so that in the first coupling state, which is accompanied by the second decoupling state, the rotor 22 and the differential shaft 44 are positively connected to one another in a rotationally fixed manner by means of the switching element UE1 and by means of the switching element SE1, and so that in the second coupling state, which is accompanied by the first decoupling state, the rotor 22 and the sum shaft 42 are positively connected to one another in a rotationally fixed manner by means of the switching element UE1 and by means of the switching element SE2.

[0062] In the second embodiment, the electric drive system 10 has a third switching element SE3, by means of which the second rotor 30 can be coupled in a rotationally fixed manner to the second differential shaft 46. For this purpose, the switching element SE3 is assigned a second switching element UE2, which is movable relative to the switching element SE3 and relative to the housing 36, in particular translationally and / or rotationally, between at least a third switching position and a fourth switching position. In the third switching position, the rotor 30 and the differential shaft 46 are connected to one another in a rotationally fixed manner by means of the switching element SE3 and by means of the switching element UE2, so that in the third switching position the third switching element SE3 is in a third coupling state.In the fourth switching position, the rotor 30 and the differential shaft 46 are decoupled from one another such that the rotor 30 and the differential shaft 46 are rotatable relative to one another about the drive axis AA, and no torque can be transmitted between the rotor 30 and the differential shaft 46 via the switching element SE3. Thus, in the fourth switching position, the third switching element SE3 is in a third decoupling state. Preferably, the switching element UE2 and the switching element SE3 are positive-locking switching elements, so that in the third coupling state, the rotor 30 and the differential shaft 46 are positively and rotationally fixedly connected to one another by means of the switching element SE3 and the switching element UE2.

[0063] In the second embodiment, a fourth shifting element SE4 is provided, which in this case is designed as a friction clutch, in particular as a multi-plate clutch. By means of the fourth shifting element SE4, the differential shaft 46 and the master shaft 42 can be connected to one another in a rotationally fixed manner. The fourth shifting element SE4 is thus a differential lock or can act or function as a differential lock.

[0064] Overall, it can be seen that the differential gear 40 is a coupling gear.

[0065] In the second embodiment, the electric drive system 10 is switchable between a first operating mode and a second operating mode. The first operating mode is also referred to as dual mode, and the second operating mode is also referred to as individual mode or single mode, for example. In the first operating mode, i.e., to activate the first operating mode, the switching element UE1 is in its Fig. 2 shown first switching position, and the switching element UE2 is in its Fig. 2, so that the switching element SE1 is in its first coupling state, the switching element SE2 is in its second decoupling state, and the switching element SE3 is in its third coupling state. To activate the second operating mode, i.e., in the second operating mode, the switching element UE1 is in its second switching position, and the switching element UE2 is in a fourth switching position, so that the switching element SE1 is in its first decoupling state, the switching element SE2 is in its second coupling state, and the switching element SE3 is in its third decoupling state.In the first operating mode, the vehicle wheels 14 and 16 can be driven, in particular simultaneously, by means of the electric machines 20 and 28, in particular such that the vehicle wheel 14 can be driven or is driven by means of the electric machine 20, bypassing the vehicle wheel 16, and, in particular simultaneously, the vehicle wheel 16 can be driven or is driven by means of the electric machine 28, bypassing the vehicle wheel 14. In the second operating mode, the vehicle wheels 14 and 16 can be driven, in particular simultaneously, with respect to the electric machines 20 and 28, exclusively by means of the electric machine 20. In other words, in the second operating mode, with respect to the electric machines 20 and 28, exclusively the electric machine 20 can drive the vehicle wheels 14 and 16.Expressed again in other words, it is provided, for example, that in the second operating mode, with respect to the electric machines 20 and 28, only the electric machine 20 drives the vehicle wheels 14 and 16, in particular simultaneously.

[0066] In the first embodiment, the spur gear pairs SP1 and SP2 are arranged on a side of the differential gear 40 facing the electric machine 20 in the axial direction of the electric drive system 10. In the second embodiment, the spur gear pair SP1 is arranged on the side of the differential gear 40 facing the electric machine 20 in the axial direction of the drive system 10, also referred to as the first side, wherein the spur gear pair SP2 is arranged on a second side of the differential gear 40 facing the electric machine 28 in the axial direction of the electric drive system 10, the second side of which faces away from the first side of the differential gear 40 in the axial direction of the electric drive system 10.In the second embodiment, the first differential shaft 44 is designed as a hollow shaft, with at least a length portion of the sum shaft 42 being accommodated in the differential shaft 44 designed as a hollow shaft. In the present case, the differential shaft 44 designed as a hollow shaft is completely penetrated by the sum shaft 42.

[0067] Fig. 3 shows a detail in a schematic representation of a third embodiment of the electric drive system 10 not falling under claim 1. In the third embodiment too, the gear Z1 and the first spur gear pair SP1 are arranged on the first side, designated S1, of the differential gear 40, wherein the gear Z2 and thus the second spur gear pair SP2 are arranged on the second side, designated S2, of the differential gear 40. As previously explained, the first side S1 of the differential gear 40 faces the electric machine 20 in the axial direction of the electric drive system 10, wherein the second side S2 of the differential gear 40 faces away from the first side S1 and the electric machine 20 in the axial direction of the electric drive system 10 and faces the electric machine 28.In the third embodiment, the first differential shaft 44 is designed as a first sun gear SO1, and the second differential shaft 46 is designed as a second sun gear SO2. Thus, the differential gear 40 is designed as a spur gear differential, in particular as a planetary differential. The summing shaft 42 is designed as a planet carrier, in particular as a double planet carrier, on which both first planet gears P1 and, additionally provided, second planet gears P2 are rotatably mounted. The respective first planet gear P1 meshes with the sun gear SO1, whereby meshing of the respective planet gear P1 with the sun gear SO2 is omitted. The respective planet gear P2 meshes with the sun gear SO2, whereby meshing of the respective planet gear P2 with the sun gear SO1 is omitted. Furthermore, a respective one of the first planet gears P1 meshes, in particular precisely, with a respective one of the second planet gears P2.For example, in the third embodiment, the differential gear 40 is free from a ring gear meshing with the planetary gears P1 and free from a ring gear meshing with the planetary gears P2.

[0068] Fig. 4 shows a detail in a schematic representation of a fourth embodiment of the electric drive system 10 not falling under claim 1. In the fourth embodiment, the differential gear 40 is designed as a bevel gear differential. Overall, it can be seen that the differential gear 40 is designed as an epicyclic gear with at least or exactly three shafts, which thus has at least or preferably exactly three shafts, namely the first differential shaft 44, the second differential shaft 46 and the summing shaft 42. In the fourth embodiment, i.e. in the case of a bevel gear differential, the summing shaft 42 is, for example, a differential carrier, also referred to as a cage or differential cage, or designed as a differential cage or cage. The summing shaft 42 is rotatable about the drive axis AA relative to the housing 36.The bevel gear differential has differential gears 56 and 58, which are held on the summation shaft 42 so as to be rotatable about a differential gear rotation axis 60 relative to the summation shaft 42 and are rotatable with the summation shaft 42 about the drive axis AA relative to the housing 36. The differential gear axis 60 runs perpendicular to the drive axis AA. In the fourth embodiment, the differential gear 40 comprises a bolt device 62 which has exactly one bolt or at least or exactly two bolts. The bolt device 62 is rotatable with the summation shaft 42 about the drive axis AA relative to the housing 36. The respective differential gear 56, 58 is held, in particular mounted, on the bolt device 62 so as to be rotatable about the differential gear rotation axis 60 relative to the bolt device 62 and relative to the summation shaft 42, such that the respective differential gear 56, 58 is rotatable about the differential gear rotation axis 60 relative to the bolt device 62.The respective differential gear 56, 58 is a respective gear which is designed as a respective bevel gear. Furthermore, the bevel gear differential has a first output gear 64 assigned to the differential shaft 44 and a second output gear 66 assigned to the differential shaft 46. The output gears 64 and 66 are gears which are designed as bevel gears. The respective output gear 64, 66 meshes with the differential gears 56 and 58 and is rotatable about the drive axis AA relative to the housing 36 and in particular relative to the master shaft 42. The output gear 64 is connected, in particular permanently, in a rotationally fixed manner to the differential shaft 44, and the output gear 66 is connected, in particular permanently, in a rotationally fixed manner to the differential shaft 46. Finally, . Fig. 5 shows a partial schematic representation of a fifth embodiment of the electric drive system 10, not falling under claim 1. In the fifth embodiment, the differential gear 40 is also designed as a bevel gear differential. In the fifth embodiment, the electric drive system 10 has the fourth shifting element SE4, which is designed, functions, can function, or is operable as a differential lock. In the fifth embodiment, the shifting element SE4 is designed as a friction clutch, in particular as a multi-disk clutch. In the fifth embodiment, the sum shaft 42 and the differential shaft 46 can be connected to one another in a rotationally fixed manner by means of the fourth shifting element SE4. It can be seen that Fig. 1 a first variant of the differential gear 40, Fig. 2 a second variant of the differential gear 40, Fig. 3 a third variant of the differential gear 40, Fig. 4 a fourth variant of the differential gear 40 and Fig. 5 shows a fifth variant of the differential gear 40. The variants of the differential gear 40 are also referred to as differential gear variants. Of course, the third variant, the fourth variant and the fifth variant of the differential gear 40 can be used in the Fig. 1 shown first embodiment of the electric drive system 10 and in the Fig. 2, so that the variants of the differential gear 40 are interchangeable with each other and as desired.

[0069] Furthermore, the Fig. The switching elements SE1, SE2, SE3 and SE4 shown in Figure 2 can be used in principle and correspondingly and then adapted also in the other embodiments and thus in the first embodiment, the third embodiment, the fourth embodiment and the fifth embodiment, so that the embodiments can be combined accordingly.

[0070] Out of Fig. 2 it can be seen that the ring gears H1 and H2 are designed, used or operable as the respective output of the differential gear 40. As already mentioned, as in Fig. 2, the second variant of the differential gear 40 can be used in other embodiments of the electric drive system 10. Since in the second embodiment, the gears Z1 and Z3 are arranged on both sides of the differential gear 40, that is, since in the second embodiment, the gear Z1 is arranged on the first side S1 of the differential gear 40 facing the electric machine 20 and the gear Z3 is arranged on the second side S2 of the differential gear 40 facing the electric machine 28 in the axial direction of the drive system 10, a two-sided output is provided in the second embodiment. In contrast, a one-sided output is provided in the first embodiment, since in the first embodiment, the gears Z1 and Z3 are arranged on the same first side S1 facing the electric machine 20 in the axial direction of the drive system 10. Fig. The double-sided output illustrated in Fig. 2 is possible in the first embodiment, wherein the gear Z3 and thus the spur gear pair SP2 are then arranged on the second side S2 of the differential gear 40 facing the electric machine 28 in the axial direction of the electric drive system 10 and facing away from the first side S1.

[0071] Out of Fig. 3 to 5, it can be seen that in the third embodiment, the fourth embodiment and the fifth embodiment, the aforementioned two-sided output is provided, since the gear Z1 is arranged on the first side S1 and the gear Z3 is arranged on the second side S2 of the differential gear 40. Of course, in the third embodiment, the fourth embodiment and the fifth embodiment, the Fig.1, in which both the gear Z1 and the gear Z3 are arranged on the first side S1. A variant of the one-sided output is of course conceivable. In this variant of the one-sided output, for example, the gears Z1 and Z3 and thus the spur gear pairs SP1 and SP2 are not arranged on the first side S1, but on the second side S2, which, in the axial direction of the electric drive system 10, points away from the electric machine 20 and from the first side S1 and faces the second electric machine 28.

[0072] By means of the fourth shifting element SE4, two of the three shafts of the differential gear 40 can be connected to one another in a rotationally fixed manner, whereby the fourth shifting element SE4 is designed, can function, or can be operated as a differential lock. The differential gear 40 can be locked by the rotationally fixed connection of two of the three shafts of the differential gear 40. Preferably, the shifting element SE4 is designed as a friction clutch, in particular as a multi-plate clutch. As a result, the two of the three shafts of the differential gear 40 can be connected to one another in a frictionally fixed manner, whereby, for example, a powershift capability of the shifting element SE4 can be realized.Alternatively, the shifting element SE4 can be designed as a positive-locking shifting element, in particular as a claw clutch, so that the two of the three shafts of the differential gear 40 can be connected to one another in a positive-locking, rotationally fixed manner by means of the shifting element SE4. This allows for particularly efficient operation. Different designs or construction variants of the shifting element SE4 are conceivable. For example, the shifting element SE4 can have a large diameter and relatively few friction plates. The shifting element SE4 can be arranged, for example, outside the aforementioned cage or inside the aforementioned cage.Of course, the switching element SE4 can be used both in the variants of the differential gear 40 in which the differential gear 40 is designed as a spur gear differential, in particular as a planetary differential, and in the variants of the differential gear 40 in which the differential gear 40 is designed as a bevel gear differential or as another differential gear.

[0073] Furthermore, it can be seen that the parking lock P in the electric drive system 10 can be implemented as a central parking lock, so that both vehicle wheels 14 and 16 can be secured against unwanted rotation relative to the housing 36 by means of the, in particular, precisely one parking lock P. This allows the number of parts, the installation space requirement, the weight, and the costs of the electric drive system 10 to be kept particularly low. List of reference symbols 10 electric drive system 12 vehicle axles 14 first vehicle wheel 16 second vehicle wheel 18 Double arrow 20 first electric machine 22 first rotor 24 first stator 26 Arrow 28 second electric machine 30 second rotor 32 second stator 34 Arrow 36 housings 38 Housing wall 40 differential gears 42 Sum wave 44 first difference wave 46 second difference wave 48 first intermediate shaft 50 second intermediate shaft 52 first output shaft 54 second output shaft 56 balance wheel 58 balance wheel 60 differential gear rotation axis 62 Bolt device 64 Output gear 66 Output gear AA drive axle ABA output shaft axis H ring gear H1 ring gear H2 ring gear P1 first planet gear P2 second planet gear P Parking lock PS S sun gear S1 page S2 page SE1 first switching element SE2 second switching element SE3 third switching element SE4 fourth switching element SO1 sun gear SO2 sun gear SP1 first spur gear pair SP2 second spur gear pair SP3 third spur gear pair SP4 fourth spur gear pair UE1 first switching element UE2 second switching element Z1 first gear Z2 second gear Z3 third gear Z4 fourth gear Z5 fifth gear Z6 sixth gear Z7 seventh gear Z8 eighth gear ZA intermediate shaft axis

Claims

[1] Electric drive system (10) for a motor vehicle, comprising: - a first electrical machine (20) having a first rotor (22); - a second electrical machine (28) having a second rotor (30); - a differential gear (40) having a sum shaft (42), a first differential shaft (44) and a second differential shaft (46); - a first intermediate shaft (48); - a second intermediate shaft (50); - a first output shaft (52); - a second output shaft (54), - a first spur gear pair (SP1) which has a first gear (Z1) connected in a rotationally fixed manner to the first differential shaft (44) and a second gear (Z2) which meshes with the first gear (Z1) and is connected in a rotationally fixed manner to the first intermediate shaft (48); - a second spur gear pair (SP2) which has a third gear (Z3) connected in a rotationally fixed manner to the second differential shaft (46) and a fourth gear (Z4) which meshes with the third gear (Z3) and is connected in a rotationally fixed manner to the second intermediate shaft (50); - a third spur gear pair (SP3) comprising a fifth gear (Z5) connected in a rotationally fixed manner to the first intermediate shaft (48) and a sixth gear (Z6) meshing with the fifth gear (Z5) and connected in a rotationally fixed manner to the first output shaft (52); and - a fourth spur gear pair (SP4), which has a seventh gear (Z7) connected in a rotationally fixed manner to the second intermediate shaft (50) and an eighth gear (Z8) meshing with the seventh gear (Z7) and connected in a rotationally fixed manner to the second output shaft (54); wherein: ◯ the first rotor (22), the second rotor (30), the sum shaft (42), the first difference shaft (44) and the second difference shaft (46) are arranged coaxially to a drive axis (AA) of the electric drive system (10) defining an axial direction of the electric drive system (10); ◯ the first intermediate shaft (48) and the second intermediate shaft (50) are arranged parallel and offset relative to the drive axis (AA); and ◯ the output shafts (52, 54) are arranged parallel and offset from each other both to the drive axis (AA) and to the first intermediate shaft (48) and to the second intermediate shaft (50), characterized bythat with regard to the axial direction, the first rotor (22), the first spur gear pair (SP1), the second spur gear pair (SP2), the fourth spur gear pair (SP4), the third spur gear pair (SP3) and the second rotor (30) are arranged one after the other in the following order: the first rotor (22) - the first spur gear pair (SP1) - the second spur gear pair (SP2) - the fourth spur gear pair (SP4) - the third spur gear pair (SP3) - the second rotor (30). [2] Electric drive system (10) according to claim 1, characterized by , that: - the first rotor (22) is or can be coupled to the first differential shaft (44), bypassing the sum shaft (42) and bypassing the second differential shaft (46); and - the second rotor (30) is or can be coupled to the second differential shaft (46) bypassing the sum shaft (42) and bypassing the first differential shaft (44). [3] Electric drive system (10) according to one of claims 1 or 2, characterized by that the third spur gear pair (SP3) and / or the fourth spur gear pair (SP4) are arranged axially overlapping the differential gear (40). [4] Electric drive system (10) according to one of the preceding claims, characterized by : - a first switching element (SE1) which is designed to couple the first rotor (22) to the first differential shaft (44) in a torque-transmitting manner; and - a second switching element (SE2) which is designed to couple the first rotor (22) to the sum shaft (42) in a torque-transmitting manner. [5] Electric drive system (10) according to claim 4, characterized by a third switching element (SE3) which is designed to couple the second rotor (30) to the second differential shaft (46) in a torque-transmitting manner. [6] Electric drive system (10) according to one of claims 4 to 5, characterized bythat the first switching element (SE1) is arranged axially between the first rotor (22) and the differential gear (40). [7] Electric drive system (10) according to one of the preceding claims, characterized by a fourth switching element (SE4) which is designed to non-positively connect two of the three said shafts of the differential gear (40) to one another. [8] Electric drive system (10) according to one of the preceding claims, characterized by that the sum shaft (42) is designed as a double planetary carrier, wherein the first differential shaft (44) is designed as a first ring gear (H1), and wherein the second differential shaft (46) is designed as a second ring gear (H2). [9] Electric drive system (10) according to one of the preceding claims, characterized bya parking lock (P), by means of which the sum shaft (42) can be connected in a rotationally fixed manner to a housing (36) of the electric drive system (10), bypassing the difference shafts (44, 46). [10] Motor vehicle, with at least one electric drive system (10) according to one of the preceding claims.

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