Electric drive system for a motor vehicle

Abstract

Electric drive system (10) for a motor vehicle, comprising a first electric machine (16) with a first rotor (20), a second electric machine (24) with a second rotor (28), and a planetary gear set (30) comprising a first planetary gear set (32), a second planetary gear set (34), a first input shaft (36), a second input shaft (38), a first output shaft (40), and a second output shaft (42), wherein: - the first input shaft (36) is configured to transmit first torques emanating from the first electric machine (16) into the planetary gear set (30), - the second input shaft (38) is configured to transmit second torques emanating from the second electric machine (24) into the planetary gear set (30), - the first output shaft (40) is configured to transmit third torques from the planetary gear set (30), - the second output shaft (42) is configured tofourth torques from the planetary gear set (30), - the first planetary gear set (32) comprises a first sun gear (44) non-rotatably connected to the first rotor (20), a first planet carrier (46) non-rotatably connected to the first output shaft (40), and a first ring gear (48) non-rotatably connected to the second output shaft (42), - the second planetary gear set (34) comprises a second sun gear (49) non-rotatably connected to the second rotor (28) and a second planet carrier (50) non-rotatably connected to the first planet carrier (46), wherein the second planetary gear set (34) comprises a second ring gear (52) non-rotatably connected to the first ring gear (48), characterized in that the first ring gear (48) and the second ring gear (52) have different tooth diameters.

Description

The invention relates to an electric drive system for a motor vehicle according to the preamble of claim 1. The US 2015 / 0 065 282 A1 is a drive machine for driving two rotating shafts as is known. Furthermore, electric drive systems for motor vehicles, each with two electric drive motors coupled to each other via a planetary gear, are known from JP 2008-215 519 A and the generic US 2007 / 0 249 456 A1. The object of the present invention is to be able to realize an electric drive system for a motor vehicle with a particularly compact design. This problem is solved by an electric drive system with the features of claim 1. Advantageous embodiments with expedient further developments of the invention are specified in the remaining claims. The invention relates to an electric drive system for a motor vehicle, in particular a car, also referred to as an electric drive device or designed as an electric drive device. 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. In particular, the motor vehicle, for example, in its fully manufactured state, has at least or exactly two axles, which are arranged consecutively in the longitudinal direction of the vehicle and thus one behind the other. Each axle has, for example, at least or exactly two wheels, also referred to as vehicle wheels, wherein the wheels of each axle are preferably arranged on opposite sides in the transverse direction of the vehicle. The wheels are ground contact elements by means of which the vehicle can be supported or is supported downwards against a ground in the vertical direction. For example, the electric drive system is assigned to at least one or exactly one of the axles, so that, for example, the wheels of at least or exactly one of the axles can be driven by means of the electric drive system. The wheels that can be driven by means of the electric drive system are also referred to as drive wheels.If the electric drive system drives the drive wheels and thus the motor vehicle, while the motor vehicle is supported downwards on the ground via the wheels in the upward direction, the motor vehicle is driven along the ground, and the wheels roll along the ground. The electric drive system comprises a first electric machine with a first rotor. For example, the first electric machine has a first stator by means of which the first rotor can be driven and thus rotated about a first machine axis of rotation relative to the first stator. The electric drive system also comprises 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 thus rotated about a second machine axis of rotation relative to the second stator. The electric drive system also comprises at least or exactly one planetary gear set, which includes a first planetary gear set, a second planetary gear set, a first input shaft, a second input shaft, a first output shaft, and a second output shaft. The first input shaft is configured to transmit a signal from the first electric machine to the first input shaft.The first electric machine, in particular via its first rotor, is configured to introduce first torques into the planetary gear set. This can be understood to mean, in particular, that the first electric machine, in particular via its first rotor, can provide the first torques that can be introduced into the planetary gear set via the first input shaft. This allows, in particular, the planetary gear set to be driven. The second input shaft is configured to introduce second torques, in particular from the second rotor, into the planetary gear set. This can be understood to mean, in particular, that the second electric machine, in particular via its second rotor, can provide the second torques that can be introduced into the planetary gear set via the second input shaft.in particular bypassing the first input shaft. This allows, for example, the planetary gear set to be driven. Furthermore, it is conceivable that the first torques can be introduced into the planetary gear set via the first input shaft, bypassing the second input shaft. This can be understood in particular as follows: The first torques that can be provided or are provided by the first electric machine, in particular by the first rotor, do not pass or flow, for example, via the second input shaft on their way from the first electric machine, in particular by the first rotor, to the planetary gear set; thus, the first torques bypass the second input shaft, so that, for example, the second input shaft, with respect to a first torque transmission path via which the torques provided by the first electric machine, in particular by the first rotor,The first torques from the first electric machine, in particular from the first rotor, can be transmitted to the first input shaft and introduced into the planetary gear via the first input shaft, provided that the first input shaft is not located in the first torque transmission path, or at least not in the first torque transmission path between the first electric machine and the planetary gear. The same applies to the second electric machine and the second torques. The second torques that can be provided or are provided by the second electric machine, in particular from the second rotor, do not, for example, flow or pass through the first input shaft on their way from the second electric machine, in particular from the second rotor, into the planetary gear; thus, the second torques bypass the first input shaft, so that, for example, the first input shaft, with respect to a second torque transmission path,via which the second torques provided by the second electric machine, in particular by the second rotor, can be transmitted from the second electric machine, in particular by the second rotor, to the second input shaft and introduced into the planetary gear via the second input shaft, is not arranged in the second torque transmission path or at least not in the second torque transmission path between the second electric machine and the planetary gear. The first output shaft is configured to transmit third torques from the planetary gear set. For example, these third torques result from the first torques and / or the second torques introduced into the planetary gear set. The second output shaft is configured to transmit fourth torques from the planetary gear set, particularly bypassing the first output shaft, wherein, for example, these fourth torques result from the first torques and / or the second torques introduced into the planetary gear set. In particular, it is conceivable that the first output shaft is configured to transmit the third torques from the planetary gear set bypassing the second output shaft. The first planetary gear set comprises a first sun gear, which is permanently and rotationally fixed to the first rotor. Furthermore, the first planetary gear set comprises a first planet carrier, which is also referred to as the first web, and which is permanently and rotationally fixed to the first output shaft. The first planetary gear set also comprises a first ring gear, which is permanently and rotationally fixed to the second output shaft.Within the scope of this disclosure, the feature that two elements, such as the first sun gear and the first rotor, are rotationally fixed to one another is understood to mean that the two elements are arranged coaxially and connected to one another in such a way that they rotate at the same angular velocity, particularly about a common axis of rotation and / or relative to a housing element of the drive system, especially when the elements, or one of the elements, and the other element via that one element, are driven. In other words, within the scope of this disclosure, the term or expression of a rotationally fixed connection between two rotatably mounted elements means that the two elements are arranged coaxially and connected to one another in such a way that they rotate at the same angular velocity.Furthermore, within the scope of the present disclosure, the feature that two elements are permanently connected to each other in a rotationally fixed manner is to be understood as meaning that these elements are not assigned a switching element which can be switched between a coupling state in which the elements are connected to each other in a rotationally fixed manner and a decoupling state in which the switching element allows a relative rotation between the elements, in particular about the aforementioned axis of rotation of the elements, but rather the elements are always, i.e., permanently, connected to each other in a rotationally fixed manner. The second planetary gear set comprises a second sun gear that is non-rotatably connected to the second rotor, preferably in a permanently non-rotatable manner. Furthermore, the second planetary gear set comprises a second planet carrier, also referred to as a second web, which is preferably permanently non-rotatably connected to the first planet carrier. The second planetary gear set also includes, for example, a second ring gear. The first sun gear, the first planet carrier, and the first ring gear are the first gear elements of the first planetary gear set. The second sun gear, the second planet carrier, and the second ring gear are the second gear elements of the second planetary gear set. Preferably, the second gear elements are provided in addition to the first gear elements.In particular, if the respective first gear element is not rotationally fixed to a housing assembly, such as the aforementioned housing element of the drive system, the respective first gear element can be rotated about a first planetary gear set axis of rotation relative to the housing assembly, which is, for example, the aforementioned housing element. Accordingly, the respective second gear element can be rotated about a second planetary gear set axis of rotation relative to the housing assembly, particularly if the respective second gear element is not rotationally fixed to the housing assembly. In order to achieve a particularly compact design, i.e., a particularly compact and therefore space-saving construction, it is provided in a manner known per se that the second ring gear of the second planetary gear set is permanently connected to the first ring gear in a rotationally fixed manner. According to the invention, the first ring gear and the second ring gear have different tooth profiles, in particular different pitch circle diameters. This allows for particularly high performance in a space-saving manner. To achieve a particularly compact and thus space-saving design of the electric drive system, one embodiment of the invention provides that the first planet carrier is designed as a single planet carrier with first planet gears. This means, in particular, that the first planet gears are rotatably mounted on the first planet carrier, specifically such that each first planet gear is rotatable about its respective first planet gear axis of rotation relative to the first planet carrier. It is particularly provided that the first planet gear axes of rotation run parallel to each other and are spaced apart. Specifically, the first planet gear axes of rotation are uniformly spaced apart in pairs in the first circumferential direction of the first planet gear set, which runs about the first planet gear set axis of rotation.It is preferably provided that the first planet gears are identical in construction to each other and, in particular, are arranged at the same height in the axial direction of the first planet gear set, and in particular start at the same first height and end at the same second height, especially when viewed in the axial direction of the first planet gear set. It has proven particularly advantageous if the second planet carrier is designed as a double planet carrier with second planet gears and third planet gears. This means, in particular, that the second planet gears and the third planet gears are rotatably mounted on the second planet carrier, specifically such that each second planet gear is rotatable about its respective second planet gear axis of rotation relative to the second planet carrier, and each third planet gear is rotatable about its respective third planet gear axis of rotation relative to the second planet carrier.It is particularly conceivable that the second planet gear axes of rotation run parallel to each other and are spaced apart, especially in the second circumferential direction of the second planet gear set, which runs around the second planet gear set axis of rotation. It is particularly conceivable that the second planet gear axes of rotation are uniformly spaced apart from each other in pairs in the second circumferential direction of the second planet gear set. Furthermore, it is conceivable that the third planet gear axes of rotation run parallel to each other and are spaced apart from each other, especially in the second circumferential direction of the second planet gear set. Preferably, the third planet gear axes of rotation are uniformly spaced apart from each other in pairs in the second circumferential direction of the second planet gear set. For example, the second planet gears can be identical in construction. Furthermore, it is conceivable that the third planet gears are identical in construction.For example, the third planet gear axes of rotation run parallel to the second planet gear axes of rotation. Thus, for example, the second planet gears are arranged at the same height in the axial direction of the second planet gear set; therefore, the second planet gears begin and end at the same heights when viewed in the axial direction of the second planet gear set. Alternatively or additionally, for example, the third planet gears are arranged at the same height in the axial direction of the second planet gear set, so that preferably the third planet gears begin and end at the same heights when viewed in the axial direction of the second planet gear set. In particular, it is conceivable that the second planet gears are identical in construction, that is, identical in terms of their design. Alternatively or additionally, the third planet gears can be identical in construction, that is, identical in terms of their design.It is particularly conceivable that the respective second and third planet gears differ from each other in their construction. Alternatively or additionally, it is conceivable that the respective second and third planet gears are arranged at the same or different heights in the axial direction of the second planet gear set, i.e., that they begin and / or end at the same or different heights. Furthermore, it is preferably provided that the first planet gears are designed separately from the second planet gears and separately from the third planet gears. For example, the second planet gears mesh with the second sun gear, and it is conceivable that the respective second planet gear does not mesh with any of the third planet gears or with the second ring gear. For example, the third planet gears mesh with the second ring gear, and it is conceivable that the respective third planet gear does not mesh with any of the second planet gears or with the second sun gear. In a further, particularly advantageous embodiment of the invention, the planetary gear set, which is also referred to as the first planetary gear set, is configured for a stationary gear ratio of +3. In other words, it is preferably provided that the first planetary gear set has a stationary gear ratio of +3. It has proven particularly advantageous if the second planetary gear set, which is also referred to as the second planetary gear set, is configured for a stationary gear ratio of -2, thus having a stationary gear ratio of -2. This allows for a particularly space-saving design. In a further, particularly advantageous embodiment of the invention, the electric drive system comprises a first transmission stage, which is also referred to as the first final drive. With respect to a first torque flow, along which the third torques can be transmitted from the planetary gear set via the first output shaft, the first transmission stage is arranged in the first torque flow and downstream of the first output shaft, thus connected downstream of the first output shaft. Conversely, the first output shaft is arranged in the first torque flow and upstream of the first transmission stage. It has proven particularly advantageous for the electric drive system to have a second transmission stage, also known as a second final drive. With respect to a second torque flow, along which the fourth torques can be transmitted from the planetary gearbox via the second output shaft, the second transmission stage is located in this second torque flow and downstream of the second output shaft. In other words, the second transmission stage is located in the second torque flow and downstream of the second output shaft. Conversely, the second output shaft is located in the second torque flow and upstream of the second transmission stage.It has proven particularly advantageous if the first transmission stage, the second transmission stage, the planetary gear sets, and the rotors are arranged in a common housing of the electric drive system. In particular, the housing can be the aforementioned housing element and / or housing assembly. Each transmission stage has, for example, at least or exactly two gears, which can be designed as spur gears. Preferably, the gears of each transmission stage are in direct meshing with one another, so that, for example, the gears form a spur gear stage or spur gear pair. By using the transmission stages, a particularly advantageous and, in particular, a particularly advantageously large transmission ratio can be achieved in a space-saving manner. To keep the installation space required for the electric drive system to a particularly small level, a further embodiment of the invention provides that the planetary gear set, the two rotors, and the two transmission stages are arranged coaxially. Preferably, the planetary gear sets are arranged coaxially so that their axes of rotation coincide. A coaxial arrangement of the rotors, meaning that the rotors are arranged coaxially, can be understood to mean, in particular, that the machine axes of rotation coincide. Thus, for example, if the rotors are arranged coaxially with each other and coaxially with the planetary gear sets, and therefore coaxially with the planetary gear set, the machine axes of rotation coincide, the planetary gear set axes of rotation coincide, and each planetary gear set axis of rotation coincides with the respective machine axis of rotation.Furthermore, it is conceivable, for example, that each transmission stage has at least one transmission element, which can be designed, for instance, as a gear, in particular as a spur gear. The respective transmission element of each transmission stage can be rotated relative to the housing, in particular about a transmission element rotation axis. If the transmission stages are arranged coaxially to each other, then the transmission elements of the transmission stages are also arranged coaxially to each other, so that the transmission element rotation axes coincide. If, for example, the transmission stages are arranged coaxially to each other, coaxially to the planetary gear set, and coaxially to the rotors, then the planetary gear set rotation axes, the machine rotation axes, and the transmission element rotation axes all coincide, thus enabling a particularly space-saving design. In order to keep the number of parts and thus the weight, costs and installation space requirements within a particularly low range, a further embodiment of the invention provides that the planetary gear has exactly two planet gear sets, namely the first planet gear set and the second planet gear set. Finally, it has proven particularly advantageous if the first rotor is permanently and rotationally fixed to the first sun gear. It has also proven particularly advantageous if the second rotor is permanently and rotationally fixed to the second sun gear. This allows for a particularly compact design. It is conceivable that each transmission stage is designed as a further planetary gear set. Thus, it is conceivable that the first transmission stage is designed as a third planetary gear set and the second transmission stage as a fourth planetary gear set, with the third planetary gear set being provided in addition to the first, second, and fourth planetary gear sets. For example, the respective transmission element mentioned above could be a sun gear, a ring gear, or a planet carrier of the respective third or fourth planetary gear set. Furthermore, it is preferably provided that each input of the respective further planetary gear set, and thus of each transmission stage, is a further sun gear of the respective further planetary gear set.Thus, for example, the third torques, which are routed from the planetary gear set via the first output shaft and, in particular, provided by the first output shaft, can be introduced into the first gear stage via the input, i.e., via the sun gear of the first gear stage, which is designed as the third planetary gear set. Furthermore, for example, the fourth torques, which are routed from the planetary gear set via the second output shaft and, in particular, provided by the second output shaft, can be introduced into the second gear stage via the input, i.e., via the sun gear of the second gear stage, which is designed as the fourth planetary gear set. It has also proven advantageous if the respective additional planet carrier of the respective additional planetary gear set, i.e., of the respective gear stage, is a respective output or driven element of the respective gear stage.Thus, for example, the first gear stage, designed as the third planetary gear set, can provide fifth torques via its additional planet carrier, and thus derive or dissipate fifth torques from itself, whereby, for example, the fifth torques result from the third torques that are or were introduced into the first gear stage, particularly via the additional sun gear of the first gear stage. Furthermore, for example, the second gear stage, designed as the fourth planetary gear set, can provide sixth torques via its additional planet carrier, and thus derive or dissipate sixth torques from itself, whereby, for example, the sixth torques result from the fourth torques that are or were introduced into the second gear stage, particularly via the additional sun gear of the second gear stage.Furthermore, it has proven advantageous if the respective additional ring gear of the respective transmission stage, designed as the third or fourth planetary gear set, is fixed to the housing, i.e., in particular permanently and non-rotatably connected to the housing, wherein the housing is, for example, the housing element and / or the housing assembly. It has proven particularly advantageous if the planetary gear set is designed or functions as a planetary differential gear set, especially with a torque vectoring function. The torque vectoring function is also referred to as a torque distribution function. Specifically, this means that the electric drive system, and thus the planetary gear set, is assigned to one of the axles and therefore to the wheels of that axle, so that the drive wheels can be driven by the electric motors via the planetary gear set. Since the planetary gear set preferably functions or is designed as a planetary differential gear set, it allows, for example, different rotational speeds of the drive wheels when the vehicle is cornering, specifically such that the outer drive wheel rotates or can rotate at a higher speed than the inner drive wheel. Also disclosed is a motor vehicle, preferably designed as a motor car, in particular the aforementioned motor vehicle, wherein the motor vehicle has an electric drive system according to the invention. Advantages and advantageous embodiments of the electric drive system are to be regarded as advantages and advantageous embodiments of the motor vehicle and vice versa. Further advantages, features, and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. The features and combinations of features mentioned above in the description, as well as those mentioned below in the figure description and / or shown in the single figure alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention. The drawing shows in the single figure a schematic representation of an electric drive system for a motor vehicle. The single figure shows a schematic representation of an electric drive system 10 for a motor vehicle. Thus, the motor vehicle, in its fully manufactured state, has the electric drive system 10, by means of which the motor vehicle can be driven, in particular purely electrically. The motor vehicle has at least or exactly two axles arranged consecutively in the longitudinal direction of the vehicle. Each axle has at least or exactly two wheels, also referred to as vehicle wheels, wherein the respective wheels of each axle are arranged on opposite sides of the motor vehicle in the transverse direction. For example, the drive system 10 is assigned to at least or exactly one of the axles, so that at least or only the wheels of the axle to which the electric drive system 10 is assigned can be driven by means of the electric drive system 10.The wheels that can be driven by means of the electric drive system 10 are also referred to as drive wheels. The drive wheels are shown schematically in the figure and are labelled 12 and 14. By driving the drive wheels 12 and 14 electrically, in particular purely, by means of the drive system 10, the motor vehicle can be driven electrically. The drive system 10 comprises a first electric machine 16, which has a first stator 18 and a first rotor 20. The rotor 20 can be driven by means of the stator 18 and thereby rotated about a first machine axis of rotation relative to the stator 18. The drive system 10 has a housing 22, shown schematically in the figure, which is also referred to as a housing assembly or housing element. The rotor 20 is rotatable about the first machine axis of rotation relative to the stator 18 and relative to the housing 22. The drive system 10 also includes a second electric machine 24, which has a second stator 26 and a second rotor 28. The rotor 28 can be driven by means of the stator 26 and thereby rotated about a second machine axis of rotation relative to the stator 26 and relative to the housing 22.In the embodiment shown in the figure, the two electric machines 16 and 24 are arranged coaxially to each other, so that their axes of rotation coincide. The first electric machine 16 can provide first torques via its first rotor 20, and the second electric machine 24 can provide second torques via its second rotor 28. The drive system 10 comprises a planetary gear set 30, which includes a first planetary gear set 32, a second planetary gear set 34, a first input shaft 36, and a second input shaft 38. The planetary gear set 30 also includes a first output shaft 40 and a second output shaft 42. The first input shaft 36 is configured to transmit the first torques emanating from the first electric machine 16, i.e., those provided by the first electric machine 16 via the rotor 20 and thus by the rotor 20, into the planetary gear set 30. The second input shaft 38 is configured to transmit the second torques emanating from the second electric machine 24, i.e., those provided by the electric machine 24 via the rotor 28 and thus by the rotor 28, into the planetary gear set 30.The first output shaft 40 is designed to transmit third torques, which result, for example, from the first and / or second torques introduced into the planetary gear 30, from the planetary gear 30. The second output shaft 42 is designed to transmit fourth torques, which result, for example, from the first and / or second torques introduced into the planetary gear 30, from the planetary gear 30. The first planetary gear set 32 ​​comprises a first sun gear 44, which is connected, in particular permanently, to the first rotor 20 in a rotationally fixed manner, and a first planet carrier 46, which is connected, in particular permanently, to the first output shaft 40 in a rotationally fixed manner. Furthermore, the first planetary gear set 32 ​​comprises a first ring gear 48, which is connected, in particular permanently, to the second output shaft 42 in a rotationally fixed manner. The second planetary gear set 34 comprises a second sun gear 49, which is connected, in particular permanently, to the second rotor 28 in a rotationally fixed manner. Furthermore, the second planetary gear set 34 comprises a second planet carrier 50, which is connected, in particular permanently, to the first planet carrier 46 in a rotationally fixed manner. In order to achieve a particularly compact design of the drive system 10 as well as particularly advantageous drivability, the second planetary gear set 34 has a second ring gear 52 which is permanently connected to the first ring gear 48 in a rotationally fixed manner. Preferably, the first planet carrier 46 is designed as a single planet carrier on which first planet gears 54 are rotatably mounted. Each first planet gear 54 meshes, for example, and preferably simultaneously, with the sun gear 44 and the ring gear 48. The second planet carrier 50 is designed, for example, as a double planet carrier on which second planet gears 56 and third planet gears 58 are rotatably mounted. The second planet gears 56 mesh with the sun gear 49 but not with the ring gear 52, while the third planet gears 58 mesh with the ring gear 52 but not with the sun gear 49. Thus, the sun gear 49 meshes with the planet gears 56, and the planet gears 58 mesh with the ring gear 52, with the planet gears 56 and 58 meshing with each other.Furthermore, the planet gears 56 do not mesh with the ring gear 52, and the planet gears 58 do not mesh with the sun gear 49. In addition, the first planet gears 54 are designed separately from the second planet gears 56 and separately from the third planet gears 58. Furthermore, it is preferably provided that the ring gears 48 and 52 have different tooth diameters, in particular different pitch circle diameters. It has proven particularly advantageous if the first planetary gear set 32 ​​is designed for a stationary gear ratio of +3. Furthermore, it has proven advantageous if the second planetary gear set 34 is designed for a stationary gear ratio of -2. The electric drive system 10 has a first transmission stage 60, which is located in the first torque flow and downstream of the first output shaft 40, along which the third torques can be transmitted from the planetary gear set 30 via the first output shaft 40. For example, a first side shaft 62 is located in the first torque flow and downstream of the first transmission stage 60. The side shaft 62 can be driven by the output shaft 40 via the transmission stage 60, whereby the wheel 12 can be driven by the side shaft 62 and thus, via the side shaft 62, by the transmission stage 60.The drive system 10 also comprises a second transmission stage 64, which is arranged in the second torque flow and downstream of the second output shaft 42, along which the fourth torques can be transmitted from the planetary gear set 30 via the second output shaft 42. A second side shaft 66 is arranged downstream of the transmission stage 64 in the second torque flow, and the wheel 14 can be driven by the transmission stage 64 via the side shaft 66. The side shaft 66 can also be driven by the output shaft 42 via the transmission stage 64. Consequently, the side shaft 62 can be driven by the output shaft 40 via the transmission stage 60. The respective transmission stages 60 and 64 are also referred to as Final Drive (FD). Preferably, the transmission stage 60 is a third planetary gear set, while it is conceivable that the transmission stage 64 is a fourth planetary gear set.Preferably, the third planetary gear set and the fourth planetary gear set are identical in construction, that is, identical or the same with regard to their design and thus, in particular, with regard to their gear ratio. It has proven particularly advantageous to arrange the transmission stages 60 and 64, the planetary gear sets 32 and 34, and the rotors 20 and 28 in the common housing 22 of the electric drive system 10. In the embodiment shown in the figure, the planetary gear set 30, the rotors 20 and 28, and the two transmission stages 60 and 64 are also arranged coaxially. Reference symbol list 10 electric drive system 12 drive wheel 14 drive wheel 16 first electric machine 18 first stator 20 first rotor 22 housing 24 second electric machine 26 second stator 28 second rotor 30 planetary gear set 32 ​​first planetary gear set 34 second planetary gear set 36 first input shaft 38 second input shaft 40 first output shaft 42 second output shaft 44 first sun gear 46 first planet carrier 48 first ring gear 49 second sun gear 50 second planet carrier 52 second ring gear 54 first planet gear 56 second planet gear 58 third planet gear 60 first reduction stage 62 first side shaft 64 second reduction stage 66 second side shaft

Claims

Electric drive system (10) for a motor vehicle, comprising a first electric machine (16) with a first rotor (20), a second electric machine (24) with a second rotor (28), and a planetary gear set (30) comprising a first planetary gear set (32), a second planetary gear set (34), a first input shaft (36), a second input shaft (38), a first output shaft (40), and a second output shaft (42), wherein: - the first input shaft (36) is configured to transmit first torques emanating from the first electric machine (16) into the planetary gear set (30), - the second input shaft (38) is configured to transmit second torques emanating from the second electric machine (24) into the planetary gear set (30), - the first output shaft (40) is configured to transmit third torques from the planetary gear set (30), - the second output shaft (42) is configured tofourth torques from the planetary gear set (30), - the first planetary gear set (32) comprises a first sun gear (44) non-rotatably connected to the first rotor (20), a first planet carrier (46) non-rotatably connected to the first output shaft (40), and a first ring gear (48) non-rotatably connected to the second output shaft (42), - the second planetary gear set (34) comprises a second sun gear (49) non-rotatably connected to the second rotor (28) and a second planet carrier (50) non-rotatably connected to the first planet carrier (46), wherein the second planetary gear set (34) comprises a second ring gear (52) non-rotatably connected to the first ring gear (48), characterized in that the first ring gear (48) and the second ring gear (52) have different tooth diameters. Electric drive system (10) according to claim 1, characterized in that: - the first planet carrier (46) is designed as a single planet carrier with first planet gears (54), - the second planet carrier (50) is designed as a double planet carrier with second planet gears (56) and third planet gears (58), and - the first planet gears (54) are designed separately from the second planet gears (56) and separately from the third planet gears (58). Electric drive system (10) according to one of the preceding claims, characterized in that:- the first planetary gear set (32) is designed for a stationary gear ratio of +3, and- the second planetary gear set (34) is designed for a stationary gear ratio of -2. An electric drive system (10) according to one of the preceding claims, characterized by: - ​​a first transmission stage (60), which, with respect to a first torque flow along which the third torques are to be transmitted from the planetary gear (30) via the first output shaft (40), is arranged in the first torque flow downstream of the first output shaft (40), and - a second transmission stage (64), which, with respect to a second torque flow along which the fourth torques are to be transmitted from the planetary gear (30) via the second output shaft (42), is arranged in the second torque flow downstream of the second output shaft (42), wherein the first transmission stage (60), the second transmission stage (64), the planetary gear sets (32, 34) and the rotors (20, 28) are arranged in a common housing (22) of the electric drive system (10). Electric drive system (10) according to claim 4, characterized in that the planetary gear (30), the two rotors (20, 28) and the two transmission stages (60, 64) are arranged coaxially to each other. Electric drive system (10) according to one of the preceding claims, characterized in that the planetary gear (30) has exactly two planet gear sets (32, 34), namely the first planet gear set (32) and the second planet gear set (34).

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