Drive device for electrically driving a vehicle, especially a passenger car

Abstract

The invention relates to a drive device (10) for electrically driving vehicle wheels, comprising: a housing (12), an electric motor (14) comprising a stator (16) and a rotor (22), a first driven shaft (26) capable of being used by the electric motor (14) to drive a first of the wheels, a first planetary gear set (30) capable of being used by the rotor (22) to drive the first driven shaft (26), a second driven shaft (28) capable of being used by the electric motor (14) to drive a second of the wheels, a second planetary gear set (32) capable of being used by the rotor (22) to drive the second driven shaft (28), and a differential (34) having an input element (36) connected in a rotationally fixed manner to the rotor (22) and capable of being used to drive the planetary gear sets (30, 32) by the rotor (22), wherein the respective ring gears (58, 60) of the respective planetary gear sets (30, 32) are connected in a rotationally fixed manner to the housing (12).

Description

Technical Field

[0001] The present invention relates to a drive device for electrically driving a vehicle, in particular a passenger car, in particular a purely electrically driven vehicle. Background Art

[0002] For example, DE 10 2017 211 881 A1 discloses a similar drive device, particularly a purely electrically driven drive device, for wheels of an axle of an automobile, particularly a passenger car. The drive device comprises an electric motor comprising a stator and a rotor. Furthermore, the drive device, particularly the electric motor, comprises a housing, in which the stator and rotor are housed. The stator is fixed to the housing and is therefore at least non-rotatably connected to the housing. The rotor can be driven by the stator and can thus rotate relative to the housing and relative to the stator about an axis of rotation. The drive device comprises a first driven shaft and a second driven shaft. Via the first driven shaft, the electric motor can electrically drive, particularly purely electrically drive, at least one or exactly one of the wheels. Via the second driven shaft, the electric motor can electrically drive, particularly purely electrically drive, at least one or exactly one of the wheels.

[0003] The drive device comprises a first planetary gear set, by which a first driven shaft can be driven electrically, in particular purely electrically, by the rotor and thus by the electric motor. The drive device also comprises a second planetary gear set, by which a second driven shaft can be driven electrically, in particular purely electrically, by the rotor. The drive device also comprises a differential, by which the planetary gear set can be driven, in particular purely electrically, by the rotor and thus by the electric motor. The differential has an input element, in particular, that is directly and non-rotatably connected to the rotor. Summary of the Invention

[0004] The object of the present invention is to improve a drive device of the aforementioned type.

[0005] This object is achieved by a drive device having the features described below. Advantageous designs with suitable inventive developments are also described below.

[0006] To improve a drive device of the type described, the present invention provides that each planetary gear set is at least predominantly, in particular completely, connected to the rotor in the axial direction of the motor and is thus arranged at least predominantly, in particular completely, outside the rotor. It is therefore preferably provided that each planetary gear set is not or not completely arranged within the rotor, but is at least predominantly, or completely, connected to the rotor in the axial direction of the motor. The feature "each planetary gear set is at least predominantly, in particular completely, connected to the rotor in the axial direction of the motor" means, in particular, that more than half of the extension of the respective planetary gear set in the axial direction of the motor, in particular the entire extension in the axial direction, extends outside the rotor and is therefore not covered by the rotor in the radial direction of the motor outward.

[0007] In an advantageous embodiment of the invention, it is provided that the respective ring gear of the respective planetary gear set is connected to the housing in a rotationally fixed manner.

[0008] In an advantageous embodiment of the invention, it is provided that the differential is at least predominantly connected to the rotor in the axial direction of the electric machine and is therefore at least predominantly arranged outside the rotor.

[0009] In an advantageous embodiment of the invention, it is provided that the differential is at least partially covered radially outwardly of the electric machine by the winding ends of the stator winding.

[0010] In an advantageous embodiment of the invention, it is provided that the first planetary carrier of the first planetary gear set is connected to the first output shaft in a rotationally fixed manner, wherein the second planetary carrier of the second planetary gear set is connected to the second output shaft in a rotationally fixed manner.

[0011] In an advantageous embodiment of the invention, it is provided that the two planetary gear sets are completely connected to the rotor in the axial direction of the electric machine and are therefore each arranged completely outside the rotor.

[0012] In an advantageous embodiment of the invention, it is provided that the differential is designed as a spur gear differential or a bevel gear differential.

[0013] In particular, the present invention allows for the realization of an electric drive coaxial with the wheels without interlocking torque-transmitting shafts. Specifically, the shaft driven by the rotor does not have a hollow shaft-like tooth structure for transmitting rotor torque, which is passed through the shaft transmitting the output torque. This avoids the need for the pitch diameter of the sun gear of each planetary gear set to follow the pitch diameter of the hollow shaft, thus enabling the sun gear to have a small pitch diameter. This in turn allows for high transmission ratios, preferably single-row or integrated planetary gear sets. Preferably, each planetary gear set, also referred to as a planetary gear mechanism, has a fixed transmission ratio in the range of 7 to 10 inclusive. The torque to be transmitted, transmitted by the differential to both output sides, is distributed equally to both sides. Due to the low torque on the sun gear, it and the associated output shaft can be designed with small diameters. This allows for high transmission ratios, particularly fixed transmission ratios of approximately 7 to 10. Furthermore, the differential can be designed to be very compact, as the torque to be transmitted is approximately 90% lower than with conventional solutions. Furthermore, forces to be supported on the housing can be avoided or kept low. Preferably, the respective bevels of the helical toothing of the gears, which are axially opposed to each other in the motor direction, are designed or arranged so as to face each other. With this helical toothing arrangement, axial forces can be supported within the differential by a suitable arrangement of the bearings within the differential, thereby compensating for their external force effects.

[0014] Because the differential's input member is rotationally fixedly connected to the rotor, the differential is directly connected to the rotor. The motor can provide torque for driving the wheels via the rotor. Because the input member is directly and rotationally fixedly connected to the rotor, the respective torque is directly or immediately transmitted from the rotor to the input member and, through the input member, to the differential. Therefore, the input member is preferably a component of the differential that initially transmits the torque provided by the rotor to the differential.

[0015] In particular, the present invention allows achieving the following advantages:

[0016] A coaxial shaft arrangement, in other words, preferably provided are output shafts which are preferably designed as solid shafts or monolithic shafts and which are arranged coaxially with one another;

[0017] -Compact and lightweight differential;

[0018] - Small construction space requirement;

[0019] - The motor and transmission can be presented as a whole within a cylindrical envelope, thus keeping the required installation space small;

[0020] - high transmission ratios, in particular fixed axis transmission ratios, can be achieved with the respective planetary gear sets;

[0021] - in particular, a total transmission ratio in the range of 8 inclusive to 11 inclusive can be achieved;

[0022] The respective planetary gears of the respective planetary gear set generate no axial forces, in particular on the respective output shaft, so that the output shaft can be mounted using a bearing that is space-saving;

[0023] The sun gears of the respective planetary gear sets, each with its oppositely helical toothing, generate mutually opposing axial forces that are supported within the differential. No other externally acting support forces arise that would have to be absorbed by the bearings in the planetary carrier or housing.

[0024] - high meshing efficiency, since preferably only one planetary gear stage is provided per output side or output shaft;

[0025] - high efficiency at the bearing points, since small bearings can be used, which are also subject to low axial loads;

[0026] - Low friction losses at the rapidly rotating rotary joints for coolants and lubricants, since these have only a small diameter. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Further advantages, features and details of the present invention are apparent from the following description of preferred embodiments and the accompanying drawings. The features and feature combinations mentioned above in the description and the features and feature combinations mentioned below in the description of the figures and / or shown individually in the figures can be used not only in the respectively indicated combination but also in other combinations or individually without exceeding the scope of the present invention. The figures show:

[0028] Figure 1 A schematic partial longitudinal section view of a drive device according to a first embodiment of the present invention is shown,

[0029] Figure 2 A partial schematic diagram of a second embodiment of the drive device is shown.

[0030] In the figures, identical or functionally identical components are provided with the same reference numerals. DETAILED DESCRIPTION

[0031] Figure 1 A schematic longitudinal section partially illustrates a first embodiment of a drive device 10 for electrically driving wheels on an axle of a vehicle, particularly a passenger car. This means that the vehicle, preferably designed as a passenger car, includes the axle, preferably having exactly two wheels in the form of the aforementioned wheels. The wheels, and thus the vehicle as a whole, can be driven, particularly purely electrically, by means of the drive device 10. To this end, the drive device 10 includes a housing 12 and an electric motor 14, which includes a stator 16 disposed within and fixed to the housing 12. This means that the stator 16 is at least rotationally fixedly connected to the housing 12. The stator 16 also has at least one winding, which forms respective winding ends 18 and 20. The winding end 18 is disposed on a first side S1 of the stator 16, while the winding end 20 is disposed on a second side S2 of the stator 16. In this case, the second side S2 faces away from the first side S1, or vice versa, in the axial direction of the electric motor 14. The respective winding end 18 or 20 is designed in particular such that the winding on the respective side S1 or S2 projects axially from a carrier of the stator 16 , which is designed as a laminated core, for example.

[0032] Electric machine 14 has a rotor 22 which is drivable by stator 16 and can thus rotate about an axis of rotation 24 relative to stator 16 and housing 12. Electric machine 14 can provide a torque via rotor 22, thereby enabling the wheels and thus the vehicle to be driven purely electrically.

[0033] Drive device 10 includes a first output shaft 26, also referred to as a first half-shaft, and a second output shaft 28, also referred to as a second half-shaft. Output shafts 26 and 28 are rotatable about an axis of rotation 24 relative to each other, the housing 12, and the stator 16. As will be explained in more detail below, they can be driven by rotor 22 and, in turn, by electric motor 14, particularly purely electrically. A first wheel can be driven by output shaft 26, while a second wheel can be driven by output shaft 28. Thus, the first wheel can be electrically driven by electric motor 14 via output shaft 26, while the second wheel can be electrically driven by electric motor 14 via output shaft 28. For example, the first wheel is arranged coaxially with output shaft 26 and / or is non-rotatably connected to output shaft 26. Alternatively or additionally, the second wheel is arranged coaxially with output shaft 28 and / or is non-rotatably connected to output shaft 28. The wheels are arranged on opposite sides of the vehicle in the transverse direction of the vehicle, so that, for example, the first wheel is located on the left side of the vehicle in the forward direction of travel, and the second wheel is located on the right side of the vehicle in the forward direction of travel.

[0034] At least or precisely one planetary gear set 30 or 32, also referred to simply as a planetary gear train, is provided for each output shaft 26 or 28. As will be explained in more detail below, the output shaft 26 can be driven by the rotor 22 via the associated planetary gear set 30, and the output shaft 28 can be driven by the rotor 22 via the associated planetary gear set 32. The drive device 10 also includes a differential gear mechanism 34, also referred to simply as a differential, by means of which the planetary gear sets 30 and 32 can be driven by the rotor 22. The differential 34 has an input element 36, which is in particular permanently connected to the rotor 22 in a rotationally fixed manner. In the example Figure 1 In the first embodiment shown, the differential 34 is designed as a spur gear differential. The input element 36 is, for example, a carrier or planetary gear carrier, on which balancing / differential gears 38, each designed separately from one another, are rotatably mounted. The differential gears 38 are gears, preferably designed as spur gears. The differential gears 38 are designed separately from one another and can rotate relative to the input element 36 and relative to one another about a second axis of rotation 42. The input element 36 is connected to the rotor 22 in a rotationally fixed manner, for example, via an input shaft 44, wherein the rotor 22 is connected to the input shaft 44 in a rotationally fixed manner and is, in particular, mounted on the input shaft 44. The input element 36 is also connected to the input shaft 44 in a rotationally fixed manner, for example.

[0035] One of the differential wheels 38 is visible in the figure, while the other differential wheel 38 is not visible. The differential 34 has driven gears 46 and 48. Driven gear 46 meshes with one of the differential wheels 38 but not with the other differential wheel 38, while driven gear 48 meshes with the other differential wheel 38 but not with one of the differential wheels 38. Driven gears 46 and 48 are each preferably designed as spur gears. Driven gears 46 and 48 are rotatable relative to one another and relative to housing 12 about axis of rotation 24. In summary, it can be seen that driven gear 46 can be driven by input member 36 via differential wheel 38, while driven gear 48 can be driven by input member 36 via the other differential wheel 38. Driven gear 46 is rotationally fixedly connected to a first output shaft 50, while driven gear 48 is rotationally fixedly connected to a second output shaft 52. Output shafts 50 and 52 are rotatable relative to one another and relative to housing 12, for example, about axis of rotation 24. The output shaft 50 is also referred to as a first differential shaft or first differential shaft, and the second output shaft 52 is also referred to as a second differential shaft or second differential shaft. Here, the planetary gear set 30 can be driven by the output shaft 50 and, in turn, by the rotor 22 via the output shaft 50, while the planetary gear set 32 ​​can be driven by the output shaft 52 and, in turn, by the rotor 22 via the output shaft 52.

[0036] Each planetary gear set 30 or 32 has a respective sun gear 54 or 56, a respective ring gear 58 or 60, respective planet gears, and a respective planet gear carrier 62 or 64. Figure 1 In particular, one of the planetary gears of the planetary gear set 30 is shown schematically and exemplarily, which is designated by 65. Figure 1, one of the planetary gears of planetary gear set 32, designated 67, is particularly schematically and exemplarily shown. The description of planetary gear 65 above and below applies immediately to the other planetary gears of planetary gear set 30, and vice versa. The description of planetary gear 67 above and below also applies immediately to the other planetary gears of planetary gear set 32, and vice versa. The planetary gears of planetary gear set 30 mesh with sun gear 54 of planetary gear set 30 on the one hand and ring gear 58 on the other hand, and are rotatably mounted on planetary gear carrier 62, also referred to as the first connecting bridge. The planetary gears of planetary gear set 32 ​​mesh with sun gear 56 and ring gear 60 of planetary gear set 32 ​​and are rotatably mounted on planetary gear carrier 64, also referred to as the second connecting bridge. Ring gears 58 and 60 are non-rotatably connected to housing 12. Sun gear 54 is non-rotatably connected to output shaft 50, and sun gear 56 is non-rotatably connected to output shaft 52. Thus, each sun gear 54 or 56 is an input to the respective planetary gear set 30 or 32, via which the torque provided by the respective output shaft 50 or 52 can be transferred to or from the respective planetary gear set 30 or 32. Each planet gear carrier 62 or 64 is an output of the respective planetary gear set 30 or 32, via which the torque for driving the respective wheels can be provided by the respective planetary gear set 30 or 32. Planet gear carrier 62 is connected to the driven shaft 26 in a rotationally fixed manner, so that the driven shaft 26 can be driven by the planetary gear set 30 via the planet gear carrier 62. Planet gear carrier 64 is connected to the driven shaft 28 in a rotationally fixed manner, so that the driven shaft 28 can be driven by the planetary gear set 32 ​​via the planet gear carrier 64.

[0037] It is provided that each planetary gear set 30 or 32 is at least largely / predominantly, in particular completely, connected to the rotor 22 in the axial direction of the electric motor 14 and is thus arranged at least largely, in particular completely, outside the rotor 22. Here, the planetary gear sets 30 and 32 are arranged on opposite sides S1 and S2 of the stator 16 or the rotor 22 in the axial direction of the electric motor 14. In particular, the ring gears arranged on both sides S1 and S2 are arranged at least largely, in particular completely, outside the rotor 22 in the axial direction of the electric motor 14.

[0038] It is provided that the differential 34 is at least largely, in particular completely, adjacent to the rotor 22 in an axial direction of the electric machine 14 coinciding with the rotational axis 24 of the output shaft 26 and is thus arranged at least largely / predominantly, in particular completely, outside the rotor 22. Here, at least the input element 36, the differential gear 38, and the output gears 46 and 48 are arranged completely outside the rotor 22 in the axial direction of the electric machine 14 and therefore do not overlap with the rotor 22 in the radial direction of the electric machine 14. The differential 34 is at least partially covered or overlapped by the winding end header 20 in the radial direction of the electric machine 14, in particular in such a way that the differential gear 38 and / or the output gears 46 and 48 are each at least partially, in particular at least largely or completely, covered or overlapped by the winding end header 20 in the radial direction of the electric machine 14. Furthermore, the two planetary gear sets 30 and 32 are completely connected to the rotor 22 and also to the stator 16 in the axial direction of the electric motor 14, so that the two planetary gear sets 30 and 32 are arranged completely outside the rotor 22 and also completely outside the stator 16 in the axial direction of the electric motor 14. Here, the planetary gear set 30 and the output shaft 26 are arranged on the side S1 of the stator 16, while the planetary gear set 32 ​​and the output shaft 28 are arranged on the side S2 of the stator 16 opposite to the side S1.

[0039] In summary, it can be seen that the differential 34 is axially connected to the rotor 22 and is not covered by the rotor 22 radially, for example. In the first embodiment, the differential 34 is arranged in the space below the winding end 20. In the first embodiment, the differential 34 is an axle differential, but it can alternatively be a bevel gear differential. Designing the differential 34 as an axle differential or a spur gear differential is advantageous in order to keep the installation space required by the differential 34 small in the axial direction.

[0040] Each planetary gear set 30 or 32 has at least or exactly one transmission stage, or one transmission stage. With respect to torque transmission (meaning the torque provided by electric motor 14 via rotor 22 and transmitted from rotor 22 to the respective wheels), a differential 34 is arranged upstream of the planetary gear sets 30 and 32, i.e., before the planetary gear sets 30 and 32. This allows the respective transmission stages to be designed for low torques, keeping the required installation space, weight, and costs low. With a transmission ratio of 7 to 12, particularly 10, this results in a torque capacity that is reduced by 90% compared to conventional solutions. The differential can thus be designed to be very space- and weight-efficient. Two output shafts 50 and 52, also referred to as differential output shafts, transmit the drive power to the two planetary gear sets 30 and 32.

[0041] Planetary gear sets 30 and 32 are as follows Figure 1As shown, they are designed as a one-piece planetary gear set or as a two-stage or two-step planetary gear set. The respective torques, also referred to as drive torques, are distributed equally, for example, by means of a differential 34, so that, for example, one half is distributed to each of the planetary gear sets 30 and 32. Due to the 50 / 50 distribution of the drive torque, the output shafts 50 and 52 can have very small diameters, allowing the respective toothing of the respective sun gear 54 or 56 to have a very small pitch circle or pitch circle diameter. This small diameter of the respective sun gear 54 or 56 allows for a favorable transmission ratio of, for example, 9, to be achieved in the respective, preferably single-stage, planetary gear set 30 or 32.

[0042] In this shaft arrangement, nested torque-transmitting shafts, such as a combination of solid and hollow shafts, are avoided. This allows, for example, the output shafts 50 and 52 to have very small diameters, enabling the selection of a tooth structure with a small pitch circle for the sun gears 54 and 56 . This small pitch circle or pitch circle diameter of the sun gears 54 and 56 allows for a favorable transmission ratio of, for example, 9, in a single-stage planetary gearset. In a typical coaxial arrangement, a shaft conducts the transmitted torque through the motor 14, and particularly through the rotor's torque-transmitting hollow shaft. This shaft's diameter should be designed for the torque being transmitted. The hollow shaft diameter depends on the shaft diameter. This defines the lower limit for the sun gear's pitch circle diameter, allowing only small transmission ratios to be achieved within a given gear path within the required space for the ring gear. To achieve high transmission ratios within a planetary gearset, particularly one with a planetary carrier, a two-stage planetary gearset with stepped planetary gears is often used, which results in a large width and, therefore, a large axial space requirement. This can be avoided in the drive device 10 .

[0043] If you can Figure 1As can be seen in FIG, drive device 10 includes bearings 66 and 68, by which planetary carriers 62 and 64 or driven shafts 26 and 28 are rotatably mounted on housing 12. Bearings 66 and 68 are, for example, rolling bearings and / or radial bearings and / or thrust bearings. Each bearing 66-68 is a slow-rotating bearing and / or a slow-rotating bearing. Drive device 10 also includes bearings 70 and 72, wherein bearing 70 rotatably mounts output shaft 50 or sun gear 54 on planetary carrier 62 or housing 12. Bearing 72 rotatably mounts output shaft 52 or sun gear 56 on planetary carrier 64 or housing 12. Bearings 70 and 72 are fast-rotating bearings or fast-rotating bearings. Bearings 70 and 72 are, for example, rolling bearings and / or radial bearings and / or thrust bearings. Drive device 10 also includes bearings 74 and 76, by which output shaft 50 is rotatably mounted on rotor 22 or input shaft 44. Each bearing 74 or 76 may be, for example, a radial bearing and / or a plain bearing and / or a needle bearing and / or may be provided only when there is a steering speed difference. The same applies, for example, to bearings 78 and 80 of drive device 10, whereby output shaft 52 is rotatably mounted on output shaft 50 via bearings 78 and 80. Furthermore, bearings 82 and 84 are provided, for example, by which input member 36, for example, is rotatably mounted on output gears 46 and 48, at least in the axial direction of motor 14. Drive device 10 also includes a bearing 86, by which output gears 46 and 48, for example, are mounted and / or supported so as to be relatively rotatable in the axial direction of motor 14.

[0044] Furthermore, a first seal 88 is provided, by means of which the driven shaft 26 is sealed relative to the housing 12. Furthermore, a seal 90 is provided, by means of which the driven shaft 28 is sealed relative to the housing 12. The seals 88 and 90 are designed, for example, as radial shaft sealing rings.

[0045] Bearings 78 and 80, also known as bearings, create a self-stable, buckling-resistant shaft assembly / arrangement between output shafts 50 and 52. Bearing 81, also known as a bearing, within the differential supplements the shaft support to provide additional stability to the shaft assembly. Bearings 74 and 76, also known as bearings, within rotor 22 radially support rotor 22 on output shaft 50. Bearings 82, 84, and 86, also known as bearings, support rotor 22 axially.

[0046] Each sun gear 54 or 56 has, for example, a helical toothing, wherein it is preferably provided that the helical toothing is designed to be opposite to one another. In other words, the helical toothing is preferably directed toward one another. With this opposing design of the helical toothing of the sun gears 54 and 56, the axial forces act in opposite directions. The axial forces are always of equal magnitude, thereby compensating for the axial forces. Bearings 82, 84, and 86, preferably designed as thrust bearings, within the differential 34 and / or rotor 22 support these forces in such a way that an axial force transmission between the two sun gears 54 and 56 is possible. As a result, no external forces or meshing forces are transmitted to the bearings 66, 68, 70, and 72.

[0047] Bearings 74, 76, 78, 80, 81, 82, 84, and 86, also known as bearings, do not experience speed differences when the vehicle is traveling straight ahead and therefore do not generate frictional power. However, only small speed differences occur when driving around curves. Low speed differences also allow the selection of simple bearings with high friction, such as plain bearings, as they have a minimal impact on efficiency. Only bearings 70 and 72, also known as bearings, on the respective sun gears 54 and 56, are subject to high speeds, but these speeds are less than the speed of the rotor. The speed of each bearing 70 or 72, which is reduced by the output shaft speed (sun gear speed minus output shaft speed), reduces frictional power. Overall, there are only four bearings, in the form of bearings 66, 68, 70, and 72, which also rotate during straight-line driving. Only two of these bearings, in the form of bearings 70 and 72, are subject to high speeds. Since bearings 66, 68, 70, and 74 do not need to transmit axial meshing forces, they can be designed to be compact. Since the shaft sections accommodating bearings 70 and 72 are not involved in the torque transmission, the minimum bearing inner diameter is not limited by the shaft's torque capacity. Small bearing diameters generate very low speed-dependent frictional power. In the presence of low or no axial forces in the rotating bearings, low load-dependent frictional work is generated. Sun gears 54 and 56 or output shafts 50 and 52 are mounted, for example, within driven shafts 26 and 28. Driven shafts 26 and 28 are in turn mounted in the housing cover or via bearings 66 and 68. No externally acting axial forces, which would need to be supported by bearings 66 and 68, occur on planetary carriers 62 and 64 or on the planetary gears. Consequently, bearings with low inertia or small diameters can be selected, thereby keeping frictional power low.

[0048] The rotor 22 can be cooled from the inside by guiding the coolant through the shaft. An annular channel is formed between the input shaft 44 and the output shaft 50, which is beneficial for cooling the rotor. In the case of a spur gear differential, a sealed coolant supply between the two driven sides can be provided, for example by means of a sealing ring. In the case of bearings 74, 76, 78 and 80 being designed as plain bearings, the coolant / lubricant circuit can be sealed by a bearing gap with a leakage point. The gear set is not then immersed in oil. Lubrication of the tooth structure, bearings and thrust plate can be ensured by oil leakage at the plain bearing. The plain bearing can also be combined with a sealing ring. Instead of a plain bearing, a rolling bearing can also be used in combination with a sealing ring.

[0049] In the case of a bevel gear differential, the interior of the bevel gear differential can be used as an oil transfer chamber. The bevel gears in the housing are immersed in oil. When coolant / lubricant circulates, it can be supplied to all components requiring lubrication, in the simplest case in the form of radial bores in the shaft. Coolant is transferred via rotary joints 92 and 94, which, for example, include or form seals 88 and 90. In particular, coolant is transferred via rotary joints 92 and 94 at low speed differences between the housing 12 and the driven shafts 26 and 28. Coolant transfer, for example, via rotary joints 96 and 98, can occur at large speed differences between the housing 12 and the driven shafts 26 and 28, but also with small seal diameters and thus with only low frictional power.

[0050] Figure 2 A second embodiment of the drive device 10 is shown. Figure 2 As indicated by arrow 100, the forces acting on the respective ring gear 58 or 60 are supported on the housing 12. As also shown by arrow 102, the forces acting on the respective sun gears 54 and 56 are supported in the shaft assembly. The magnitude of the forces on the left and right is always the same, since forces can only occur if they are supported on both sides by the drive resistance. The torque imbalance or force imbalance is compensated by the differential. No axial forces act on the respective driven shafts 26 or 28, since the planetary gear sets are in principle axially force-free or axially force-neutral. The bearings in the differential and / or in the rotor 22 can absorb axial forces, more precisely tensile and / or compressive forces. The support is provided, for example, by means of sliding bearing rings or thrust needle roller bearings and a tooth structure in the differential. It is also possible to see clearly that Figure 2 The opposing helical teeth of the sun gears 54 and 56 can be seen in FIG.

[0051] Preferably, bearings 70 and 72 are arranged outside the torque transmission path of shafts 26 and 52, that is, not between the sun gears 54, 56 of the planetary gear sets and the driven gears 46, 48 of the differential 34, but in the planetary gear carriers 62, 64 or the driven shafts 26, 28.

[0052] It can also preferably be provided that, by means of three thrust bearings 82, 84 and 86 in the differential 34 and by fixedly connecting the sun gear or central gear 46, 48 to the shafts 50, 52, it is possible to support axial forces arising from meshing forces directly via the bearing 86 or via bearings 82 and 84 and the planetary gear carrier of the input element 36 or the differential 34, depending on the direction of the force.

[0053] It is preferably provided that bearings 78 and 80 mounted on or in shaft 52 are spaced apart to such an extent, in particular at least at a distance of twice the average bearing diameter, that the shaft can be aligned or supported in a stable and bending-resistant manner relative to the rotor.

[0054] It may also be preferably provided that the shaft 50 passes through the input shaft 44 or the rotor 22 and thus rotatably supports the rotor 22 on the bearings 74 , 76 .

[0055] It is preferably provided that the output shafts 50 and 52 have inlets and outlets and channels for guiding the cooling fluid / lubricating fluid, and that the input shaft 44 and the output shaft 50 form an annular space for guiding the fluid for cooling the rotor.

[0056] Reference Signs List

[0057] 10. Drive unit

[0058] 12 Housing

[0059] 14 Motor

[0060] 16 stator

[0061] 18 Winding ends

[0062] 20 Winding end

[0063] 22 rotors

[0064] 24 Rotation axis

[0065] 26 driven shaft

[0066] 28 driven shaft

[0067] 30 planetary gear sets

[0068] 32 planetary gear sets

[0069] 34 differential

[0070] 36 Input

[0071] 38 differential wheels

[0072] 42 Rotation axis

[0073] 44 Input shaft

[0074] 46 driven gear

[0075] 48 driven gear

[0076] 50 Output shaft

[0077] 52 Output shaft

[0078] 54 center gear

[0079] 56 center gear

[0080] 58 ring gear

[0081] 60 ring gear

[0082] 62 planetary gear carrier

[0083] 64 planetary gear carrier

[0084] 65 Planetary Gear

[0085] 66 bearings

[0086] 67 Planetary Gear

[0087] 68 bearings

[0088] 70 bearings

[0089] 74 bearings

[0090] 76 bearings

[0091] 78 bearings

[0092] 80 bearings

[0093] 81 bearings

[0094] 82 bearings

[0095] 84 bearings

[0096] 86 bearings

[0097] 88 seals

[0098] 90 Seals

[0099] 92 rotary joint

[0100] 94 swivel joint

[0101] 96 rotary joint

[0102] 98 rotary joint

[0103] 100 arrows

[0104] 102 Arrow

[0105] S1 side

[0106] S2 side

Claims

1. A drive device (10) for electrically driving a wheel of an automobile axle, comprising: - housing (12); an electric motor (14) comprising a stator (16) and a rotor (22), the stator being arranged in the housing (12) and being fixed to the housing (12), the rotor being arranged in the housing (12) and being drivable by the stator (16) and thus being rotatable relative to the housing (12) and relative to the stator (16) about an axis of rotation (24); a first driven shaft (26) via which the electric motor (14) drives at least one first wheel of the wheels; - a first planetary gear set (30), via which the rotor (22) drives the first driven shaft (26); a second driven shaft (28), via which the electric motor (14) drives at least one second of the wheels; a second planetary gear set (32), via which the rotor (22) drives the second driven shaft (28); and a differential (34) having an input (36) connected to the rotor (22) in a rotationally fixed manner and through which the rotor (22) drives the first planetary gear set (30) and the second planetary gear set (32), The planetary gear sets (30, 32) are at least mainly connected to the rotor (22) in the axial direction of the electric motor (14) and are therefore at least mainly arranged outside the rotor (22). The differential (34) is at least mainly connected to the rotor (22) in the axial direction of the electric motor (14), and is therefore at least mainly arranged outside the rotor (22). The first output shaft (50) and the second output shaft (52) transmit the driving power from the differential (34) to the first planetary gear set (30) and the second planetary gear set (32), wherein the first output shaft (50) passes through the input shaft (44), and the first output shaft (50) is rotatably mounted on the input shaft (44) via two bearings (74, 76), wherein the rotor (22) is connected to the input shaft (44) in a rotationally fixed manner and is arranged on the input shaft (44). Its characteristics are: The differential (34) is designed as a spur gear differential and is provided with two further bearings (78, 80) arranged on the second output shaft (52) or in the first output shaft (50), wherein the two further bearings (78, 80) are arranged at least twice the average bearing diameter apart from each other, and the second output shaft is rotatably supported in the first output shaft via the two further bearings.

2. The drive device (10) according to claim 1, characterized in that The respective ring gear (58, 60) of each planetary gear set (30, 32) is connected to the housing (12) in a rotationally fixed manner.

3. The drive device (10) according to claim 1 or 2, characterized in that: The differential (34) is at least partially covered by the winding ends (20) of the stator (16) windings in the radial direction outward of the electric machine (14).

4. The drive device (10) according to claim 1 or 2, characterized in that: The first planetary gear carrier (62) of the first planetary gear set (30) is connected to the first driven shaft (26) in a rotationally fixed manner, wherein the second planetary gear carrier (64) of the second planetary gear set (32) is connected to the second driven shaft (28) in a rotationally fixed manner.

5. The drive device (10) according to claim 1 or 2, characterized in that: The first planetary gear set (30) and the second planetary gear set (32) are completely connected to the rotor (22) in the axial direction of the electric motor (14) and are therefore respectively arranged completely outside the rotor (22).

6. The drive device (10) according to claim 1 or 2, characterized in that: The input member (36) is connected to the rotor (22) via the input shaft (44) in a rotationally fixed manner.

7. The drive device (10) according to claim 1 or 2, characterized in that: Two thrust bearings (82, 84) are provided, by means of which an input member (36) is mounted on two driven gears (46, 48) rotatably at least in the axial direction of the motor (14), and the drive device (10) includes another thrust bearing (86) by which the two driven gears (46, 48) are supported rotatably relative to each other in the axial direction of the motor (14).

8. The drive device (10) according to claim 1 or 2, characterized in that: The first output shaft (50) and the second output shaft (52) have inlets and outlets and channels for guiding cooling fluid / lubricating fluid, and the input shaft (44) and the first output shaft (50) form an annular space for guiding the cooling fluid / lubricating fluid.

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