Electric drive device for a motor vehicle, in particular for a motor car, as well as motor vehicle

Abstract

Electric drive device (10) for a motor vehicle, comprising: - a case (20), - an electric machine (12) designed to propel the motor vehicle, which has a rotor (16), - a planetary gear set (22) arranged at least partially in the housing (20), comprising a first planet gear set (24) with a first sun gear (28) connected to the rotor (16) in a non-rotatable manner, a first planet carrier (30) and a first ring gear (32) and a second planet gear set (26) with a second planet carrier (34) and a second ring gear (36) connected to the first planet carrier (30) in a non-rotatable manner, - at least two switching elements, namely a first switching element (S1) and a second switching element (S2), for switching at least two gears, - a differential gear (42) which has a differential input shaft (44) and two output shafts (46, 48), wherein the second planetary gear set (26) has a second sun gear (56) which is non-rotatably connected to the differential input shaft (44), characterized by the fact that the second switching element (S2) is designed to lock the second planetary gear set (26).

Description

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

[0002] DE 10 2013 225 519 A1 discloses a planetary gear for a motor vehicle, comprising an input shaft forming a sun gear, a planet carrier carrying a first set of planet gears and a second set of planet gears, a first ring gear associated with the first set of planet gears, and a second ring gear associated with the second set of planet gears. A first locking means is also provided for locking the first ring gear. Furthermore, a second locking means is provided for locking the second ring gear.

[0003] The CN 2 03 713 556 U also shows the above-mentioned features and, in addition, that a second planetary gear set has a second sun gear which is non-rotatably connected to a differential input shaft.

[0004] The object of the present invention is to create an electric drive device for a motor vehicle and a motor vehicle, such that a particularly low-loss and compact design can be realized.

[0005] This problem is solved by an electric drive device with the features of claim 1 and by a motor vehicle with the features of claim 9. Advantageous embodiments with expedient further developments of the invention are specified in the remaining claims.

[0006] A first aspect of the invention relates to an electric drive device for a motor vehicle, in particular for a motor vehicle preferably designed as a passenger car. This means that the motor vehicle, preferably designed as a motor vehicle, in particular as a passenger car, in its fully manufactured state, has the electric drive device and can be driven, in particular purely electrically, by means of the electric drive device. For this purpose, the electric drive device comprises a housing and at least one electric machine by means of which the motor vehicle can be driven, in particular purely electrically. The electric machine has a rotor. For example, the electric machine also has a stator by means of which the rotor can be driven and thereby rotated about a machine axis of rotation relative to the stator.In particular, the electric machine can provide drive torques via its rotor to propel the motor vehicle. For example, the electric machine, especially its rotor, can drive at least or exactly two vehicle wheels (also simply called wheels) on an axle of the motor vehicle, thereby propelling the motor vehicle.

[0007] The electric drive device also includes a planetary gear set, which is arranged at least partially, and in particular at least predominantly and thus at least more than halfway or completely, within the housing. The planetary gear set comprises a first planetary gear set and a second planetary gear set. The first planetary gear set includes a first sun gear, which is, in particular, permanently and non-rotatably connected to the rotor. The first planetary gear set also includes a first planet carrier, also referred to as the first carrier, and a first 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 planetary gear set includes a second planet carrier, which is, in particular, permanently and non-rotatably connected to the first planet carrier. The second planetary gear set also includes a second ring gear.The second planet carrier and the second ring gear are the second gear elements of the second planetary gear set. Particularly when the respective gear element is not rotationally fixed to the housing and is driven, especially by the application of the respective drive torque or a torque resulting from the respective drive torque, the respective gear element is rotatable about a gear element axis relative to the housing. It is particularly conceivable that the first gear elements are arranged coaxially with each other. Alternatively or additionally, for example, the second gear elements are arranged coaxially with each other. Preferably, the planetary gear sets are arranged coaxially with each other. Alternatively, it is conceivable that the planetary gear sets are arranged off-axis with each other.

[0008] The electric drive device also comprises a first switching element and a second switching element. The switching elements are designed for switching at least two gear ratios of the electric drive device, in particular the planetary gear. Within the scope of this disclosure, a rotationally fixed connection between two rotatable or rotatably mounted elements means that these two elements are arranged coaxially to one another and connected to each other in such a way that they rotate at the same angular velocity, in particular about an element axis of rotation and / or relative to the housing, especially when one of the elements, and thus the other element, is driven. In particular, the respective element can be the respective gear element. In particular, the element axis of rotation can be the gear element axis of rotation.Preferably, the rotor is arranged coaxially to at least one of the planetary gear sets, in particular to both planetary gear sets, also referred to as planetary sets, so that, for example, the machine axis of rotation coincides with the gear element axis of rotation.

[0009] The characteristic that elements are permanently connected or coupled to each other in a rotationally fixed manner means that a switching element is not provided which can be switched between a coupling state in which the elements are connected or coupled to each other in a rotationally fixed manner and a decoupling state in which the elements are decoupled from each other and rotatable relative to each other so that no torques can be transmitted between the elements, but rather the elements are always, i.e., permanently, connected or coupled to each other in a rotationally fixed manner.

[0010] The electric drive system also includes a differential gear, which is assigned, for example, to the aforementioned axle and thus, for example, to the vehicle wheels, which can be driven by the electric machine via the rotor. In particular, the vehicle wheels can be driven by the rotor via the differential gear. As is already well known, the differential gear has, for example, the function of allowing different rotational speeds of the vehicle wheels when the vehicle is cornering, such that the outer wheel rotates at a higher speed than the inner wheel, especially while the vehicle wheels are driven by the rotor and thus by the electric machine via the differential gear.

[0011] The differential gear has a differential input shaft through which the respective drive torque, or a respective torque resulting from the respective drive torque, can be introduced into the differential gear, thereby driving the differential gear and, via it, the wheels. Furthermore, the differential gear comprises two output shafts, which can be driven by the differential input shaft. In particular, the vehicle wheels can be driven by the output shafts, specifically such that a first wheel can be driven by a first output shaft and the second wheel by a second output shaft. Preferably, the rotor is also arranged coaxially with the output shafts.

[0012] To achieve a particularly low-loss and compact design for the electric drive device, the second planetary gear set is provided, in a known manner, with a second sun gear, which constitutes a further, second transmission element of the second planetary gear set. Furthermore, the second sun gear is permanently and rotationally fixed to the differential input shaft.

[0013] For example, the respective first gear element, if it is not rotationally fixed to the housing, is rotatable about a first gear element axis of rotation relative to the housing, where the first gear element axis of rotation is also referred to as the first planetary gear set axis of rotation. It is conceivable that the respective second gear element, particularly if it is not rotationally fixed to the housing, is rotatable about a second gear element axis of rotation relative to the housing, where the second gear element axis of rotation is also referred to as the second planetary gear set axis of rotation. Since the planetary gear sets are preferably arranged coaxially, the planetary gear set axes of rotation and the gear element axes of rotation coincide. If the planetary gear sets are arranged disaxially, the gear element axes of rotation run parallel to each other and are spaced apart.

[0014] According to the invention, the second switching element is designed to lock the second planetary gear set.

[0015] Thus, the second switching element is a locking switching element by means of which the planetary gear set, in particular its entirety, can be locked. For this purpose, the second switching element is designed, for example, to lock two gear elements of the planetary gear set that are not already, in particular permanently, rotationally fixed to one another. Thus, the second switching element can, for example, be switched or adjusted between a second coupled state and a second uncoupled state. In the second coupled state, two elements of the planetary gear set that are not already permanently rotationally fixed to one another are rotationally fixed to one another by means of the second switching element, thereby locking the entire planetary gear set.In the second decoupling state, the second switching element releases the elements for a rotation relative to each other around the axis of rotation of the gear element, thereby removing the locking of the planetary gear.

[0016] To achieve particularly advantageous drivability in a compact and low-loss manner, one embodiment of the invention provides that the first switching element is designed to connect the second ring gear to the housing in a rotationally fixed manner. In particular, the first switching element is designed to be switchable between a first coupled state and a first disengaged state. In the first coupled state, the second ring gear is connected to the housing in a rotationally fixed manner by means of the first switching element, and thus fixed to the housing in a rotationally fixed manner. Therefore, the second ring gear cannot rotate about the axis of rotation of the transmission element relative to the housing, even when the second ring gear is driven.In the first decoupling state, the first switching element releases the second ring gear for rotation relative to the housing about the axis of rotation of the gear element, so that the second ring gear is rotatable or is rotated about the axis of rotation of the gear element relative to the housing, in particular when the second ring gear is driven.

[0017] For example, the first switching element is movable, particularly relative to the housing and / or translationally, between at least one first coupling position that effects the first coupling state and at least one first decoupling position that effects the first decoupling state. Furthermore, it is conceivable that the second switching element is movable, particularly translationally and / or relative to the housing, between at least one second coupling position that effects the second coupling state and at least one second decoupling position that effects the second decoupling state.

[0018] At least one of the switching elements, in particular the second switching element, can be designed, for example, as a positive-locking switching element such as a jaw coupling, or may have a positive-locking switching element such as a jaw coupling. Furthermore, it is conceivable that at least one of the switching elements, such as the first switching element, is designed as a force-locking or friction-locking switching element, or may have such a force-locking or friction-locking switching element, by means of which, for example, one of the transmission elements can be connected to another of the transmission elements or to the housing in a force-locking or friction-locking manner, transmitting torque, in particular in a rotationally fixed manner. The friction-locking switching element is also referred to as a friction-locking coupling and may, for example, be designed as a multi-plate clutch.The positive-locking switching element is also referred to as a positive-locking coupling and can, for example, be designed as a jaw coupling. The positive-locking switching element is specifically designed to connect two of the transmission elements, or one of the transmission elements and the housing, to each other in a rotationally fixed manner by means of at least one positive locking element, which is formed, for example, by at least two solid bodies overlapping each other in at least one or both directions of rotation about the axis of rotation of the transmission element.In contrast, the friction-fit switching element can connect two of the transmission elements or one of the transmission elements and the housing, in particular exclusively, in a rotationally fixed manner by friction or frictional forces, for example by connecting at least two friction partners to each other in a torque-transmitting manner, in particular in a rotationally fixed manner, for example without the friction partners overlapping each other around the axis of rotation of the transmission element.

[0019] To minimize losses, a further embodiment of the invention provides that the second switching element comprises a positive-locking switching element, in particular a jaw coupling. By means of the jaw coupling, for example, two of the transmission elements or one of the transmission elements and the housing can be positively locked and rotationally fixed to one another in at least one or exactly one or both directions of rotation around the axis of rotation of the transmission element.

[0020] To achieve particularly advantageous drivability in a space-saving, weight-efficient, and cost-effective manner, a further embodiment of the invention provides that the second switching element has a freewheel clutch arranged or connected parallel to the jaw clutch and also simply referred to as a freewheel. By means of the freewheel clutch, for example, two of the transmission elements or one of the transmission elements and the housing can be connected or linked together in a rotationally fixed manner in a first direction of rotation around the axis of rotation of the transmission element, whereby, or while the freewheel clutch allows relative rotations between the transmission elements or between the transmission element and the housing in a second direction of rotation around the axis of rotation of the transmission element, opposite to the first direction of rotation. Preferably, the freewheel clutch is or acts in a positive-locking manner, which allows losses to be kept particularly low.

[0021] In order to achieve particularly advantageous drivability and, in particular, a particularly advantageous multi-speed capability in a particularly compact and low-loss manner, a further embodiment of the invention provides that the second switching element is designed to connect the second sun gear to the second ring gear in a rotationally fixed manner. This allows, for example, the planetary gear set to be particularly advantageously locked in place.

[0022] Another embodiment is characterized in that the electric drive device has a parking lock wheel which is permanently and non-rotatably connected to the second sun wheel. The parking lock wheel is, for example, part of a parking lock that can be activated and deactivated. When the parking lock is activated, the parking lock wheel, and consequently the second sun wheel, are prevented from rotating relative to the housing around the axis of rotation of the transmission element. This prevents, for example, the vehicle from rolling away unintentionally, especially when the vehicle is parked on a slope. When the parking lock is deactivated, the parking lock wheel, and thus the second sun wheel, can rotate, particularly around the axis of rotation of the transmission element and relative to the housing, so that, for example, the vehicle can roll down a slope.This allows for a particularly advantageous drivability of the motor vehicle in a particularly low-loss and space-saving manner.

[0023] In order to keep costs and weight particularly low, a further embodiment of the invention provides that the first ring gear is permanently connected to the housing in a rotationally fixed manner.

[0024] Finally, it has proven particularly advantageous if the second planetary gear set is arranged axially overlapping the differential gear. This allows the length of the drive device extending in the axial direction of the planetary gear to be kept especially short.The feature that the second planetary gear set is arranged axially overlapping with the differential gear means in particular that the second planetary gear set is at least partially, in particular at least predominantly and thus at least more than half or even completely, overlapped or covered by the differential gear in the radial direction of the second planetary gear set and thus along a direction perpendicular to the axis of rotation of the gear element and thus in particular from the second sun gear to the second ring gear, especially with regard to an extension or length of the second planetary gear set extending in the axial direction of the planetary gear set.

[0025] A second aspect of the invention relates to a motor vehicle, preferably designed as a motor car, in particular as a passenger car, which has at least or exactly one electric drive device according to the invention and, in particular, can be driven purely electrically by means of the drive device. 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.

[0026] In particular, the invention allows the following advantages to be realized: - loss-optimized and compact design At least one of the switching elements can be designed as a positive-locking switching element, such as a dog brake or dog clutch, or can have such a positive-locking switching element and, if necessary, the aforementioned freewheel, which allows losses to be kept particularly low. In the case of a conversion to a freewheel, this is located, for example, on a suitable inner diameter. - Relative speeds in open-running switching elements can be kept particularly low. - The switching elements can be very easily accessible. - Stresses on the switching elements can be kept particularly low. - good gear efficiency, especially in first gear - The rotational speeds of the electric machine can be kept particularly low at high speeds, especially due to the multiple turns of the planetary gear.

[0027] A friction- or force-locking switching element, such as the first switching element, has the particular advantage that it allows for at least a largely load-shiftable operation, possibly with a certain reduction in traction force, but without interruption of traction force, especially when changing from one of the gears to the second gear and / or vice versa.

[0028] Particularly with regard to kinematic equivalence, which is to be regarded as implicitly included or disclosed in the present case, it may be provided that a single planetary carrier in a planetary gear set can be replaced by a double planetary carrier, especially if the connections of the two other gear elements of this planetary gear set are exchanged at the same time. For example, in a planetary gear set, a switching element, especially one designed as a brake switching element, for fixed connection to the housing, can be replaced by a permanent fixed connection to the housing, especially if a switching element is simultaneously installed in a fixed connection of the two other gear elements of this planetary gear set; that is, for example, if a fixed connection of the two other gear elements of this planetary gear set is simultaneously replaced by a switching element.

[0029] Advantageously, the differential gear is designed as a bevel gear differential, in particular with a differential cage, wherein the differential cage can be permanently, rotationally fixed to the differential input shaft or wherein the differential cage can form the differential input shaft.

[0030] 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 those mentioned below in the figure description and / or shown in the figures 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.

[0031] The drawing shows in: Fig. 1 A schematic representation of an electric drive device for a motor vehicle; and Fig. 2 A switching table to illustrate switchable, i.e., selectable and selectable gears of the electric drive device.

[0032] In the figures, identical or functionally equivalent elements are provided with the same reference symbols.

[0033] Fig. Figure 1 shows a schematic representation of an electric drive device 10 for a motor vehicle. Preferably, the motor vehicle, which is designed in particular as a car and especially as a passenger car, has at least or exactly two axles arranged one behind the other in the longitudinal direction of the vehicle, which are also referred to as vehicle axles. Each axle has at least or exactly two wheels, which are also referred to as vehicle wheels and which are the ground contact elements of the motor vehicle. The respective wheels of each axle are arranged on opposite sides of the motor vehicle in the transverse direction. The motor vehicle can be supported or is supported downwards against a road surface by means of the wheels, which are designed as ground contact elements of the motor vehicle.If the motor vehicle is driven electrically by means of the drive device 10, in particular purely electrically, while the motor vehicle is supported downwards against the road surface in the vertical direction, the wheels roll along the road surface. For example, the drive device 10 is exclusively and thus exactly assigned to one of the axles, so that, for example, only the wheels of the axle to which the drive device 10 is assigned can be driven by means of the drive device 10.

[0034] The drive device 10 comprises an electric machine 12, which has a stator 14 and a rotor 16. The rotor 16 can be driven by means of the stator 14 and is thus rotatable about a machine axis 18 relative to the stator 14 and also relative to a housing 20 of the drive device 10. Via the rotor 16, the electric machine 12 can provide drive torque to drive the wheels of the axle to which the electric machine 12 or the drive device 10 is assigned. The wheels that can be driven by the electric machine 12 via its rotor 16 are also referred to as drive wheels. The drive device 10 also includes the [missing information - likely a component or component]. Fig. Figure 1 shows a housing 20, which is shown schematically, and to which, for example, the stator 14 is fixed in a rotationally fixed manner. The drive device 10 has a planetary gear set 22, which comprises a first planetary gear set 24 and a second planetary gear set 26. Preferably, the planetary gear sets 24 and 26 are each arranged at least partially, and in particular at least predominantly and thus at least more than halfway or completely, in the housing 20, so that the planetary gear set 22 is at least partially arranged in the housing 20. Furthermore, the rotor 16 is arranged, for example, coaxially with the planetary gear sets 24 and 26. The planetary gear set 24 has a first sun gear 28, a first planet carrier 30, and a first ring gear 32, wherein the first planet carrier 30 is referred to as the first web. The sun gear 28, the planet carrier 30, and the ring gear 32 are also referred to as the first gear elements.In particular, if the respective first gear element is not rotationally fixed to the housing 20, the respective first gear element can be rotated about a first gear element rotation axis relative to the housing 20.

[0035] The second planetary gear set 26 has a second planet carrier 34 and a second ring gear 36. The planet carrier 34 is also referred to as the second web. The planet carrier 34 and the ring gear 36 are second gear elements of the second planetary gear set 26. In particular, if the respective second gear element is not rotationally fixed to the housing 20, the respective second gear element is rotatable about a second gear element axis of rotation relative to the housing 20. Since in the Fig. In the embodiment shown in Figure 1, the planetary gear sets 24 and 26 are arranged coaxially to each other, the gear element rotation axes coincide, and since the rotor 16 is arranged coaxially to the planetary gear sets 24 and 26, the gear element rotation axes coincide with the machine rotation axis 18.

[0036] The planetary gear set 24 also comprises at least one or more first planet gears 38. Each first planet gear 38 is rotatably mounted on the planet carrier 30 and meshes, for example, directly with the sun gear 28 and the ring gear 32. The planetary gear set 26 comprises at least one or more second planet gears 40. Each second planet gear 40 is rotatably mounted on the planet carrier 34 and meshes, in particular directly, with the ring gear 36. The drive device 10, in particular the planetary gear set 26, comprises a first switching element S1, which is also designated B. Furthermore, the drive device 10, in particular the planetary gear set 22, comprises a second switching element S2, which is also designated K. By means of the switching elements S1 and S2, at least or exactly two gear ratios of the drive device 10, in particular of the planetary gear set 22, can be engaged.Thus, the switching elements S1 and S2 are configured to switch at least or exactly two gears of the drive device 10, in particular the planetary gear set 22. This means that the two gears can be engaged and disengaged by means of the switching elements S1 and S2. The first gear is also referred to as first gear 1, and the second gear is also referred to as second gear 2. In particular, the gears differ from each other with respect to their gear ratios, specifically such that the gear ratio of first gear 1 is higher than the gear ratio of second gear 2.

[0037] The drive device 10 also includes a differential gear 42, which can, for example, be designed as a bevel gear differential. The differential gear 42 has a differential input shaft 44, through which the respective drive torque or a respective torque resulting from the respective drive torque can be introduced into the differential gear 42. This drives the differential input shaft 44, also simply referred to as the input shaft, and thus the differential gear 42. Furthermore, the differential gear 42 comprises two output shafts 46 and 48, which can be driven by the input shaft. This allows the output shafts 46 and 48 to each drive a torque resulting from the input shaft. Fig. 1. Provide the torque illustrated by arrows 50, by means of which the wheels of the axle to which the drive device 10 is assigned can be driven. For example, the differential 42 comprises differential gears 52 that mesh with output gears 54 of the differential 42. The output gears 54 are gears that are, in particular, permanently and non-rotatably connected to the output shafts 46 and 48. The differential gears 52 are also gears. Preferably, the rotor 16 is arranged coaxially with the output shafts 46 and 48, which are arranged coaxially with each other. This means, in particular, that the output shafts 46 and 48 are rotatable about a common output shaft axis of rotation relative to the housing 20, wherein the machine axis of rotation 18 and the output shaft axis of rotation coincide. Fig. It is also evident from Figure 1 that the first sun gear 28 is permanently and rotationally fixed to the rotor 16. Furthermore, the planet carrier 34 is permanently and rotationally fixed to the planet carrier 30.

[0038] In order to achieve a particularly low-loss and compact design of the drive device 10, the second planetary gear set 26 has a second sun gear 56, which is a further second transmission element of the second planetary gear set 26. In addition, the second sun gear 56 is permanently and rotationally fixed to the differential input shaft 44.

[0039] The first switching element S1 is designed to connect the second ring gear 36 to the housing in a rotationally fixed manner. In the case of the Fig. In the embodiment shown in Figure 1, the switching element S1 is a friction- or force-locking switching element, in particular a multi-plate clutch, whereby it is particularly conceivable that the switching element S1 is free of a positive-locking switching element. Thus, it is conceivable that the switching element S1 is designed to connect the ring gear 36 to the housing 20 exclusively by friction or force-locking in a rotationally fixed manner.

[0040] The second shell element S2 is preferably designed to block the planetary gear 22. In the case of the Fig. In the embodiment shown in Figure 1, the switching element S2 is designed to connect the second ring gear 36 to the second sun gear 56 and thus to the differential input shaft 44 in a rotationally fixed manner. In the embodiment shown in Fig. In the embodiment shown in Figure 1, the second switching element S2 has a positive-locking switching element in the form of a jaw coupling 58, by means of which the planetary gear 22 can be locked, in particular in at least or exactly one or both axes of rotation extending around the axis of rotation of the gear element, in particular such that the ring gear 36 can be positively and rotationally connected to the differential input shaft 44 and, in particular, via the latter to the sun gear 56, by means of the jaw coupling 58 in a rotationally fixed manner in at least or exactly one or both axes of rotation extending around the axis of rotation of the gear element. Furthermore, the switching element S2 has, according to Figure 1, a positive-locking switching element in the form of a jaw coupling 58. Fig. 1. A freewheel clutch 60, also simply referred to as a freewheel, is arranged or connected in parallel to the dog clutch 58. By means of the freewheel (freewheel clutch 60), the ring gear 36 can be connected or linked to the differential input shaft 44 and the sun gear 56 in a first direction of rotation about the axis of rotation of the transmission element, in particular by means of a positive locking connection, and in particular while the freewheel allows relative rotations between the ring gear 36 and the sun gear 56 or the differential input shaft 44 in a second direction of rotation about the axis of rotation of the transmission element, opposite to the first direction of rotation.

[0041] The drive device 10 also includes a parking lock gear 62 of a parking lock 64, wherein the parking lock gear 62 is, in particular, permanently and rotationally fixed to the differential input shaft 44 and thus to the sun gear 56. This secures the differential input shaft 44 and the sun gear 56, and in particular the output shafts 46 and 48 and thus the drive gears, against rotation relative to the housing 20 when the parking lock 64 is activated. This is achieved by the parking lock gear 62 being positively and rotationally fixed to the housing 20. This prevents such rotation, thus securing the vehicle against unwanted rolling, especially when the vehicle is parked on a slope. Furthermore, the first ring gear 32 is permanently and rotationally fixed to the housing 20.Furthermore, the planet gear set 26 is arranged axially overlapping with the differential gear 42, whereby the planet gear set 26 is at least partially overlapped or covered by the differential gear 42 in the radial direction of the planet gear set 26 and thus along a direction perpendicular to the axis of rotation of the gear element and thus from the sun gear 56 towards the ring gear 36.

[0042] At the in Fig. In the embodiment shown in Figure 1, the switching element S2 follows both planetary gear sets 24 and 26 in the axial direction of the planetary gear set 22. In an embodiment not shown in the figures, the second switching element S2 is arranged between the planetary gear sets 24 and 26 in the axial direction of the planetary gear set 22. Furthermore, it is conceivable that the second ring gear 36 can be connected to the planet carrier 30 and thus to the planet carrier 34 in a rotationally fixed manner by means of the switching element S2. It is also conceivable that the switching element S2 is designed as a friction-locking switching element and is, in particular, free of a positive-locking switching element, so that, for example, the planetary gear set 22 can be locked, in particular, purely by friction or force-locking, by means of the switching element S2. Furthermore, it is conceivable that, particularly starting from the point shown in Figure 1, the second ring gear 36 can be connected to the planet carrier 30 and thus to the planet carrier 34 in a rotationally fixed manner. Fig. In the embodiment shown in Figure 1, the freewheel (freewheel clutch 60) is omitted, so that, for example, the switching element S2 only has the dog clutch 58 and is therefore free of a freewheel. For all embodiments, it is conceivable that the switching element S2 is arranged in the axial direction of the planetary gear set 22 between the planet gear sets 24 and 26. In a further embodiment not shown in the figures, it is possible that the differential input shaft 44, and thus the second sun gear 56, can be connected to the ring gear 36 in a rotationally fixed manner by means of the switching element S2, wherein the switching element S2 preferably only has the dog clutch 58 and follows both planet gear sets 24 and 26 in the axial direction of the planetary gear set 22.

[0043] In another embodiment, not shown in the figures, it is conceivable that the switching element S2 comprises only the freewheel (freewheel clutch 60). In particular, the freewheel can follow both planetary gear sets 24 and 26 in the axial direction of the planetary gear set 22. This embodiment has the advantage that only the freewheel is used and the dog clutch 58 is omitted, so that no hydraulically or electromechanically controlled switching element needs to be provided. However, this could result in a reduction in recuperation, because the freewheel would be open during deceleration and thus during recuperation.An advantage of the respective embodiments, in which the switching element S2 has the dog clutch 58 and the freewheel or only the freewheel, is in particular that during a gear change, for example from first gear 1 to second gear 2, wherein the second switching element, which is also designated K, is so to speak a moving clutch, and the switching element S1, which is also designated B, is so to speak an approaching clutch, the dog clutch of the switching element K can be opened first, if dog clutches are present, whereby the switching element K is then still closed via the freewheel (freewheel clutch 60), as soon as a torque is transmitted at the switching element B, in particular a braking torque at the switching element B, the switching element K becomes load-free and the freewheel of the switching element K opens automatically, so to speak at the right time.This is advantageous compared to a pure claw coupling, since a claw coupling cannot be opened under load, or at least not very conveniently.

[0044] Furthermore, it is conceivable that the switching element S1 is designed as a positive-locking switching element, in particular as a claw coupling, and is in particular free of a friction-locking switching element.

[0045] Fig.Figure 2 shows a shift table in which first gear is denoted by 1, second gear by 2, the gear ratios of gears 1 and 2 by i, the gear spread by Φ, the first shift element S1 by B, the second shift element S2 by K, and η is the gear efficiency of the respective gear 1 or 2. To engage first gear 1, shift element B is open and shift element K is closed. To engage gear 2, shift element B is closed and shift element K is open. For example, the gear ratio i of first gear 1 is in a range from 5 to 6 inclusive, and in particular from 5 to 5.5 inclusive. For example, the gear ratio i of gear 2 is in a range from 2 to 3 inclusive, and in particular from 2 to 2.5 inclusive.For example, the pitch spread Φ lies in a range from 2 inclusive to 3 inclusive, in particular in a range from 2 inclusive to 2.5 inclusive. For example, the gear efficiency in the first gear 1 is at least 98%, and the gear efficiency in the second gear 2 is, for example, at least 97%. Reference symbol list 10 electric drive device 12 electric machine 14 Stator 16 Rotor 18 Machine rotary axis 20 cases 22 planetary gears 24 first planetary gear set 26 second planetary gear set 28 first ring gear 30 first planetary carrier 32 first ring gear 34 second planetary carrier 36 second ring gear 38 first planetary gear 40 second planetary gear 42 Differential gear 44 Differential input shaft 46 Output shaft 48 Output shaft 50 Arrow 52 Compensating wheel 54 Output gear 56 second sun wheel 58 Claw coupling 60 Freewheel clutch 62 Parking lock wheel 64 Parking restrictions S1 first switching element S2 second switching element

Claims

[1] Electric drive device (10) for a motor vehicle, comprising: - a case (20), - an electric machine (12) designed to propel the motor vehicle, which has a rotor (16), - a planetary gear set (22) arranged at least partially in the housing (20), comprising a first planet gear set (24) with a first sun gear (28) connected to the rotor (16) in a non-rotatable manner, a first planet carrier (30) and a first ring gear (32) and a second planet gear set (26) with a second planet carrier (34) and a second ring gear (36) connected to the first planet carrier (30) in a non-rotatable manner, - at least two switching elements, namely a first switching element (S1) and a second switching element (S2), for switching at least two gears, - a differential gear (42) which has a differential input shaft (44) and two output shafts (46, 48), wherein the second planetary gear set (26) has a second sun gear (56) which is non-rotatably connected to the differential input shaft (44), characterized by , that the second switching element (S2) is designed to lock the second planetary gear set (26). [2] Electric drive device (10) according to claim 1, characterized by , that the first switching element (S1) is designed to connect the second ring gear (36) to the housing (20) in a rotationally fixed manner. [3] Electric drive device (10) according to claim 1 or 2, characterized by , that the second switching element (S2) has a claw coupling (58). [4] Electric drive device (10) according to claim 3, characterized by , that the second switching element (S2) has a freewheel clutch (60) arranged parallel to the claw clutch (58). [5] Electric drive device (10) according to any one of the preceding claims, characterized by, that the second switching element (S2) is designed to connect the second sun gear (56) to the second ring gear (36) in a rotationally fixed manner. [6] Electric drive device (10) according to any one of the preceding claims, characterized by a parking lock wheel (62) which is non-rotatably connected to the second sun wheel (56). [7] Electric drive device (10) according to any one of the preceding claims, characterized by , that the first ring gear (32) is permanently connected to the housing (20) in a rotationally fixed manner. [8] Electric drive device (10) according to any one of the preceding claims, characterized by , that the second planetary gear set (26) is arranged axially overlapping with the differential gear (44). [9] Motor vehicle, with an electric drive device (10) according to any of the preceding claims.

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