Electric drive arrangement and drive train with such an electric drive arrangement

Abstract

The invention relates to an electric drive arrangement for propelling a motor vehicle, comprising: an electric machine (2), a planetary gear unit (4) and a switching device (5) for the planetary gear unit, wherein the planetary gear unit (4) has a planet carrier (9) rotatably driven by the electric machine (3), several planet gears (10) rotating with the planet carrier (9) and two sun gears (11, 12), wherein a first of the two sun gears (11, 12) is designed as an output part for driving a downstream output unit (70) and, wherein a second of the two sun gears (12, 11) is operatively connected to the switching device (5) such that the second sun gear (12) is supported in a first switching position on a stationary component (7) in the direction of rotation, and in a second switching position is non-rotatably connected to a first output shaft (25) of the output unit (70) driven by the first sun gear (11).

Description

[0001] The invention relates to an electric drive arrangement for the powertrain of a motor vehicle. The invention further relates to powertrain arrangements with such an electric drive arrangement. Electric drive arrangements are known which are designed as the sole drive and / or as an auxiliary drive to a primary drive source for propelling the motor vehicle.

[0002] For example, DE 60 2004 002 073 T2 discloses an electric drive arrangement with three coupled planetary stages that drive an electric motor with an output shaft. The output shaft is directly connected to the planet carrier of one of the planetary stages in the power flow. The electric drive arrangement includes a switching device with a brake and a clutch, which can assume four different switching states by opening and closing the brake and clutch, respectively. In all switching states, the output shaft can be rotated relative to the sun gears of all planetary stages.

[0003] From the applicant's German patent application DE 10 2015 103 584 A1, an electric drive with an electric machine and a transmission arrangement is known. The transmission arrangement comprises a first transmission unit in the form of a spur gear with a drive gear and an output gear offset from it, a second transmission unit in the form of a planetary gear, and a third transmission unit in the form of a differential gear. The planetary gear has several planet gears, a planet carrier, a first sun gear, and a second sun gear. The first sun gear can be supported on a housing via a controllable clutch. The second sun gear is drive-connected to the differential housing of the differential gear. When the clutch is open, the electric machine is decoupled from the differential gear. When the clutch is closed, torque is introduced into the differential gear.

[0004] Furthermore, drive arrangements for variable torque distribution in the drivetrain of a motor vehicle are known, which are also referred to as torque vectoring systems. For example, such a drive arrangement in the form of a transmission module is known from DE 10 2005 004 290 A1. The transmission module comprises a first shaft with a first sun gear, a second shaft with a second sun gear, several planet gears that mesh with the first and second sun gears, and a support element carrying the planet gears. The support element can be coupled to a stationary housing by means of a coupling, so that torque is transmitted between the first and second shafts.

[0005] From US patent 2008 0064552 A1, a differential unit with controllable torque and speed distribution is known. The differential unit comprises a differential gear driven by a vehicle engine, a superimposed gear in the form of a planetary gear set, and an auxiliary drive in the form of an electric motor. The planetary gear set includes two sun gears, two ring gears, and two sets of planet gears. A first sun gear is connected to the auxiliary drive, a second sun gear is rotationally fixed to a housing, and the two ring gears are connected to two links of the differential gear set.

[0006] From WO 2010 101506 A1 a torque vectoring device is known, comprising a first electric motor as a drive source, a differential gear with two output shafts driven by the first electric motor, a second electric motor for torque distribution between the two output shafts and control means with which the second electric motor can be controlled on the basis of a plurality of variables representing the driving dynamics of the motor vehicle.

[0007] The present invention is based on the objective of proposing an electric drive arrangement for the powertrain of a motor vehicle that, in the smallest possible installation space, enables not only the drive function but also variable torque distribution. The further objective is to propose corresponding powertrain arrangements incorporating such an electric drive arrangement.

[0008] These tasks are each solved by the respective subject matter of independent claims 1, 14, 15 and 16. Advantageous embodiments are specified in the dependent claims.

[0009] One solution consists of an electric drive arrangement for propelling a motor vehicle, comprising: an electric machine for generating a drive torque; a planetary gear unit for transmitting the drive torque to an output unit; and a switching device for the planetary gear unit;wherein the planetary gear unit comprises a planet carrier driven by the electric machine to rotate about an axis of rotation, several planet gears rotating with the planet carrier, and two sun gears, wherein the planet gears each have a first and a second toothed section, wherein a first of the two sun gears is drive-connected to the first toothed sections of the planet gears and is designed as an output part for driving a downstream output unit, and wherein a second of the two sun gears is drive-connected to the second toothed sections of the planet gears and is operatively connected to the switching device such that the second sun gear is supported in a first switching position on a stationary component in the direction of rotation, and in a second switching position is rotationally fixed to a first output shaft of the output unit driven by the first sun gear.

[0010] One advantage of this electric drive arrangement is its versatility: it can be used as an additional power source to propel the vehicle, for variable torque distribution between two output shafts of the drive axle, or for generating asymmetrical torque between the two drive shafts, depending on the requirements. Furthermore, the arrangement is compact and simple in design, as it comprises only one electric motor, which, however, can perform different functions depending on the control system.

[0011] Within the scope of this disclosure, stationary components are defined as all components on which a rotationally fixed support is possible, such as a housing part of the electric drive assembly. The planetary gear unit can comprise two, three, or more planet gears, which are preferably distributed regularly around the circumference. Where the terms "rotatably driven" or "drive-connected" are used herein, this is intended to include the possibility that one or more further components may be interposed in the power path between a driving component and the component being rotatably driven by it. For example, pairs of meshing planet gears could also be provided in the power path between the planet carrier and the two sun gears.It is also conceivable that a controllable coupling is arranged in the power path between two drive-connected components, which can optionally establish or interrupt torque transmission.

[0012] In the first switching position of the switching device, the second sun gear is supported against a stationary component in the direction of rotation. This means that any torque applied to the second sun gear by the electric motor is supported, allowing the full torque to be transmitted via the first sun gear to the output unit downstream in the power path. In this switching position, the planetary gear unit operates like a conventional reduction gearbox, so the downstream drive train is driven at a correspondingly slower rate by the electric drive arrangement.

[0013] In the second switching position, the second sun gear is rotationally fixed to an output shaft of the output unit. This means that the reduction ratio formed by the planetary gear unit is effective between the output unit driven by the first sun gear and the output unit connected to the second sun gear. In this switching position, the electric machine operates as a torque vectoring device, which can transmit torque variably to one of the output shafts of the output unit depending on the direction of rotation of the electric machine.

[0014] With a further embodiment, the switching device can be moved into a third switching position in which the second sun gear can rotate freely. In this switching position, which can also be referred to as the neutral position, the electric machine is decoupled from the drive train.

[0015] The planetary gear set is designed so that torque applied to the planet carrier is transmitted via the planet gears to the two sun gears. The planet carrier functionally serves as the input component, through which torque is applied by the electric motor. The first sun gear acts as the output component of the planetary gear set, driving the downstream drive unit of the drive train. The second sun gear serves as the link to the switching device, which allows the operating mode of the electric drive system to be changed. Therefore, the second sun gear can also be functionally described as the actuating component of the planetary gear set.

[0016] The planet carrier of the planetary gear unit can be cage-shaped and have two sleeve projections for mounting the planet carrier on both sides in a stationary housing. The planet gears are connected to the planet carrier in such a way that their planet gear axes rotate around the planet carrier's axis of rotation. Each planet gear has a first toothed section that meshes with the first sun gear and a second toothed section that meshes with the second sun gear. The first and second toothed sections of the planet gears can have the same or a different number of teeth. For ease of manufacturing, it is advantageous if the first and second toothed sections of a planet gear are identical.The first and second sun gears can have the same number of teeth or – even if the two gear sections of the planetary gears have the same number of teeth – a different number of teeth. In the latter case, the tooth profiles of the first and second sun gears can be offset relative to each other.

[0017] According to one possible embodiment, the switching device can have a controllable switching element and a coupling element movable by the switching element, wherein the coupling element is rotationally fixed to the stationary component in the first switching position and rotationally fixed to the first output shaft in the second switching position. The coupling element is preferably rotationally fixed and axially movable to the second sun gear. For this purpose, the sun gear can have an integrally formed sleeve extension or be connected to a shaft journal at the end of which longitudinal teeth are provided, on which the coupling element sits with corresponding mating teeth, rotationally fixed and axially movable.

[0018] The electric drive arrangement can further comprise the output unit driven by the first sun gear, which may be connected to the planetary gear set. According to one possible embodiment, the output unit can be designed as a differential gear unit. The differential gear preferably has a differential carrier connected to the first sun gear, several differential gears rotating with the differential carrier, and two side shaft gears meshing with the differential gears. A first of the two side shaft gears is non-rotatably connected to the first output shaft, and the second side shaft gear is non-rotatably connected to, or can be non-rotatably connected to, the second output shaft. The output shafts serve to drive a corresponding right or left wheel of the vehicle's drive axle, which is driven by the electric drive arrangement.In one possible embodiment, the planetary gear set and the differential gear set are arranged coaxially and laterally offset from each other. More specifically, the planet carrier and the differential housing can be arranged coaxially and axially offset from each other.

[0019] An electric drive arrangement according to the invention can be used in various powertrain arrangements. For example, the powertrain to which the electric drive arrangement is assigned can be a primary and / or a secondary powertrain of the motor vehicle. Furthermore, an electric drive arrangement can be designed as the sole drive for an associated powertrain, or as a superimposed drive, which can additionally be driven by another drive source, for example, an internal combustion engine. In this case, a further input element for introducing torque from the additional drive source is preferably provided on the differential housing.

[0020] As explained above, the electric machine can perform two functions depending on the switching position of the switching device: as a drive source for the vehicle's drivetrain or as a device for variable torque application to one of the two output shafts of the driven unit. The electric machine can be controlled, in particular, by an electronic control unit (ECU), which receives various sensor data relating to the vehicle's driving dynamics as input variables, such as the vehicle's speed, yaw rate, steering angle, and / or throttle position. The electric machine is preferably connected to a battery, which supplies the electric machine with electrical energy in motor mode and can be recharged by the electric machine in generator mode.The electric machine preferably has a stator that is rigidly connected to a stationary component and a rotor for transmitting torque to a rotatable component.

[0021] In one possible embodiment, the electric machine can be arranged coaxially with the planetary gear unit, wherein, in particular, a rotor of the electric machine, or a motor shaft connected thereto, is driven by the planet carrier of the planetary gear unit. In a first specification, the electric machine can be arranged radially outside the planetary gear unit with axial overlap, wherein the rotor of the electric machine can be non-rotatably connected to a section of the planet carrier. In a second specification, the electric machine can be arranged with axial offset and radial overlap with the planetary gear unit, wherein the rotor of the electric machine can be non-rotatably connected to a sleeve extension of the planet carrier.

[0022] According to a further embodiment, the electric machine can also be arranged with an axial offset relative to the axis of rotation of the planetary gear unit. In further detail, the electric machine can be arranged with an axial offset and / or an angular offset relative to the planetary gear unit. In other words, the term "axial offset" within the scope of this disclosure is intended to encompass a translational and / or an angular offset.

[0023] The electric drive arrangement can further include a transmission unit, which may be arranged in the power path between the electric motor and the planetary gear unit. The transmission unit is specifically designed to reduce the rotary motion initiated by the electric motor. The precise design can be selected according to available space and other technical requirements, in order to compensate for any axis misalignment between the motor axis of rotation of the electric motor and the axis of rotation of the planet carrier. For example, the transmission unit can be designed as a spur gear, chain drive, belt drive, or bevel gear.

[0024] The electric drive assembly can have a common housing, which includes the possibility that individual units are housed in separate housing sections, with the individual housing sections being interconnected. For example, the housing can have one section housing the clutch and another housing section housing the planetary differential unit. The two housing sections can be rigidly connected, for example, via flange, bolt, and / or weld connections.

[0025] One solution to the above-mentioned problem further comprises a drivetrain arrangement for a multi-axle motor vehicle, comprising: a first drivetrain with a first drive axle that can be driven by a first power source; and a second drivetrain with a second drive axle that can be driven by an electric drive arrangement designed according to at least one of the above-mentioned embodiments, wherein the first drive axle and the second drive axle are mechanically unconnected, i.e., designed separately such that only the first drivetrain can be driven by the first power source and only the second drivetrain by the electric drive arrangement. In the first switching position of the electric drive arrangement, a torque can be applied by the electric machine to the second drive axle in order to drive the motor vehicle alternatively or in addition to the first power source.In the second switching position, variable torque distribution or application to the first or second output shaft is possible (torque vectoring function). This is achieved primarily by the electric motor generating a drive torque between the differential housing and one of the output shafts of the second drive axle. Depending on the direction of rotation of the electric motor, this drive torque can be positive or negative, thus selectively driving either one or the other output shaft.

[0026] One solution to the above-mentioned problem further comprises a drivetrain arrangement for a multi-axle motor vehicle, comprising: a first drive axle which can be driven by a first drive source via a first drivetrain, a second drive axle which can be driven by a second drivetrain from the first drive source and which is connected to an electric drive arrangement designed according to at least one of the above-mentioned embodiments. In other words, in this embodiment, the first and second drive axles are mechanically connected to each other, for example, via a longitudinal drive shaft. In the first switching position of the electric drive arrangement, an additional torque can be introduced from the electric machine to the second drive axle, the introduced torque being distributed evenly between the two output shafts.In the second switching position, a variable torque can be superimposed on the torque applied by the first drive source, allowing for an unequal torque distribution between the first and second output shafts (torque vectoring function). Depending on the direction of rotation of the electric machine, the drive torque can be positive or negative, thus selectively driving either one or the other output shaft. The drive torque of the electric machine is superimposed on the torque applied by the first drive source, the latter of which can, in principle, also be zero.

[0027] One solution to the above-mentioned problem further comprises a powertrain arrangement for a motor vehicle, comprising: a first drive source, in particular an internal combustion engine, a stepped gear unit downstream of the first drive source in the power path, a differential gear unit downstream of the stepped gear unit in the power path, and an electric drive arrangement designed according to at least one of the above embodiments, wherein the differential housing of the differential gear unit is connected to the stepped gear unit and to the planetary gear unit. In the first switching position of the switching device, an additional torque can be applied to the differential housing by the electric motor.In the second switching position, a variable torque can be superimposed on a torque introduced by the first drive source, so that an unequal torque distribution can be set between the first and second output shafts (torque vectoring function). This can be done, in particular, as described above.

[0028] The aforementioned drivetrain arrangements essentially offer the same advantages mentioned above in connection with the electric drive arrangement: a functionally versatile controllability of the drivetrain, i.e., drive function and variable torque distribution, in the smallest possible installation space.

[0029] Preferred embodiments are explained below with reference to the drawing figures. These show: Fig. 1 an electric drive arrangement according to the invention in a first embodiment in semi-longitudinal section; Fig. 2 the electric drive arrangement Fig. 1 schematically in longitudinal section; Fig. 3 an electric drive arrangement according to the invention in a second embodiment in semi-longitudinal section; Fig. 4 the electric drive arrangement Fig. 3 schematically in longitudinal section; Fig. 5 a schematic longitudinal section of an electric drive arrangement according to the invention in a third embodiment; Fig. 6 a schematic longitudinal section of an electric drive arrangement according to the invention in a fourth embodiment; Fig. 7 a schematic longitudinal section of an electric drive arrangement according to the invention in a fifth embodiment; Fig. 8 a schematic longitudinal section of an electric drive arrangement according to the invention in a sixth embodiment; Fig. 9 a drive train arrangement with an electric drive arrangement according to the invention Fig. 4; Fig. 10 a drive train arrangement with an electric drive arrangement according to the invention Fig. 5; Fig. 11 a drive train arrangement with an electric drive arrangement according to the invention Fig. 6.

[0030] The Fig. 1 and Fig. Figures 2, which are described together below, show an electric drive arrangement 2 according to the invention in a first embodiment. The electric drive arrangement 2 comprises an electric machine 3, a planetary gear unit 4 driven by the electric machine 3, and a controllable switching device 5 with which the operating mode of the electric drive arrangement can be changed.

[0031] The electric machine 3 has several functions: it serves as a drive source for powering the drivetrain of a motor vehicle and as a device for variable torque distribution between two drive axles of the drivetrain. The electric machine 3 is controlled by an electronic control unit (ECU). For power supply, the electric machine 3 is connected to a battery (not shown). The electric machine 3 has a stator 6, which is rigidly connected to a housing 7, and a rotor 8, which is rigidly connected to the input part of the planetary gear set 4 for torque transmission.

[0032] The planetary gear 4 comprises a planet carrier 9 as its input element, several planet gears 10, and two sun gears 11, 12. The planet gears 10 are attached to the planet carrier 9 such that they rotate about the axis of rotation A9 of the planet carrier 9. The planet carrier 9 is cage-shaped and has a receiving section 13 in which the planet gears 10 are received, as well as two sleeve extensions 14, 15 which are rotatably mounted about the axis of rotation A9 in the housing 7 of the electric drive assembly 2 via bearings 16, 17. The planet carrier 10 is, in particular, constructed in two parts and comprises a cup-shaped part and a lid-shaped part, which are firmly joined together, in particular by welding.

[0033] The planet gears 10 are each rotatably mounted on a journal 19 connected to the planet carrier 9 by means of radial bearings 18 about a respective journal axis A19 and axially supported against the planet carrier 9 by means of thrust bearings 20, 20'. The planet gears 10 each have a first toothed section 21 which meshes with a first sun gear 11, and a second toothed section 22 which meshes with a second sun gear 12.

[0034] The first sun gear 11 has connecting means 23 for connecting it to a driven output unit (not shown), which can, for example, be designed in the form of a differential gear, as will be discussed in more detail below. In this case, the first sun gear 11 is connected to a hollow shaft 24, which is rotatably mounted on an output shaft 25 of the output unit. The sun gear 11 and hollow shaft 24 are designed as a single unit, although it is understood that the two components can also be manufactured separately and subsequently joined together. The sun gear 11 and the hollow shaft 24 are mounted on the output shaft 25 using plain bearings, although rolling bearings are also possible. The first sun gear 11 is sealed against the output shaft 25 by means of a shaft seal 27, which is seated in an internal circumferential groove of the first sun gear 11.The annular space formed between the hollow shaft 24 and the housing 7 is sealed by means of a further shaft seal 28.

[0035] The second sun gear 12 is axially adjacent to and coaxial with the first sun gear 11. An axial bearing 29 is arranged between the opposing end faces of the two sun gears 11 and 12, providing axial support for them. Similar to the first sun gear 11, the second sun gear 12 also has a sleeve extension 30 and is rotatably mounted on the output shaft 25. The sleeve extension 30 is functionally connected to the switching device 5.

[0036] The switching device 5 can be controlled by an electronic control unit to actively influence the vehicle's driving dynamics. Specifically, the switching device 5 can be moved into three switching positions, which result in different operating modes of the electric drive arrangement 2.

[0037] In the first switching position of the switching device 5, the second sun gear 12 is rotationally fixed to the housing 7. A torque applied to the planet gear 10 is supported by the second sun gear 12, so that the full torque is transmitted via the first sun gear 11 to the downstream output unit. In this switching position, the planetary gear unit 4 operates like a conventional reduction gear, so that the drive train is driven by the electric drive arrangement 2 with the corresponding reduction ratio.

[0038] In the second switching position, the second sun gear 12 is rotationally fixed to the output shaft 25 of the output unit. The reduction formed by the planetary gear unit 4 is effective between the link of the output unit driven by the first sun gear 11 and the link (25) of the output unit connected to the second sun gear 12. In this switching position, the electric machine 3 operates as a torque vectoring device, which can transmit torque asymmetrically to one of the output shafts 25, 26 of the output unit, depending on the direction of rotation.

[0039] In the third switching position, the second sun gear 12 is free of torque, meaning it can rotate freely. In this switching position, which can also be called the neutral position, the electric machine 3 is decoupled from the drive train.

[0040] Similar to the control of the electric motor, the control system for actuator 5 is also based on several sensor readings relating to the vehicle's driving dynamics, such as speed, yaw rate, steering angle, and / or throttle position. Depending on requirements or the driving dynamics state, actuator 5 can be controlled, particularly in a rule-based manner, to assume one of the three switching positions.

[0041] The switching device 5 can, in principle, be designed in any way depending on the technical requirements. The crucial factor is that three switching positions can be reliably set. According to the present embodiment, the switching device 5 comprises an axially movable switching element 32 and a coupling element 33 that is rotationally fixed and axially movable with the second sun gear 12. The coupling element 33 is connected to the hollow shaft 30 via a longitudinal toothing 38, allowing rotational and axial movement. The switching element 32 is designed to move the coupling element 33 into three coupling positions. Specifically, the switching element 32 can be designed in the form of a switching fork, which is held axially movable on a pin 37 and can be moved by an actuator (not shown). Similarly, the coupling element 33 can be designed in the form of a switching sleeve with a circumferential groove into which the switching fork can engage with sliding blocks to move the switching sleeve axially.

[0042] In the first coupling position, the coupling element 33 is positively connected to the housing 7 via first form engagement means 34, 34', so that the coupling element 33 and thus the second sun gear 11 are supported against rotation on the housing 7. This position is reached when the switching element 32 and the coupling element 33 axially connected to it are disengaged from the housing 7. Fig. 1. The form engagement means 34 of the coupling member 33 engage in the form engagement means 34' of the housing 7.

[0043] In the second coupling position, the coupling element 33 is rotationally fixed to the output shaft 25 via second form engagement means 35, 35'. For this purpose, an intermediate element 36 is provided, which is rotationally and axially fixed to the output shaft 25. The rotationally fixed connection can be achieved via a shaft spline. Axial locking is provided by means of a retaining ring 39. The second coupling position is reached when the switching element 32 and the coupling element 33 axially connected to it are disengaged from the Fig. 1 position shown, moved to the right so that the forming engagement means 35 of the coupling member 33 engage in the forming engagement means 35' of the intermediate element 36.

[0044] The third position (neutral) is in Fig. Figure 1 shows that the coupling element 33 is not connected to either the housing 7 or the intermediate element 36, so that the second sun wheel 12 can rotate freely.

[0045] The housing 7 of the electric drive assembly 2 is designed in multiple parts and comprises a first housing section 40, in which the planetary differential unit 4 is housed, and a second housing section 42, in which the shift clutch 5 is housed. The second housing section 42 is connected to the first housing section 40 via flange or screw connections 43. An intermediate wall 44 is formed between the two housing spaces. Fig. 1 further sees that the output shaft 25 is rotatably mounted in the housing 18 via a bearing 45 and sealed via a shaft seal 46.

[0046] The Fig. 3 and Fig. Figures 4, which are described together below, show a further embodiment of the electric drive arrangement 2 according to the invention. The electric drive arrangement 2 largely corresponds to that shown in Figures 4. Fig. 1 and Fig. 2, so that all similarities are referred to in abbreviated form by reference to the description above. Identical or corresponding details are marked with the same reference symbols as in the Fig. 1 and Fig. 2.

[0047] As in the embodiment described above, the present electric drive arrangement 2 also comprises an electric machine 3, a planetary gear unit 4, and a controllable switching device 5. A difference lies in the arrangement of the electric machine 3, which in the present embodiment is arranged axially offset from the planetary gear unit 4. Specifically, the electric machine 3 is arranged such that at least a radially inner part of the electric machine 3, in particular the rotor, has radial overlap with at least a partial section of the planet gears 10. This results in a radially very compact, but axially somewhat longer, design than in the embodiment according to the Fig. 1 and Fig. 2.

[0048] To accommodate the planetary gear set 4 and the electric machine 3 side by side, the housing 7 is correspondingly long. The stator 6 of the electric machine 3 is connected to the housing section 40 of the housing 7. The rotor 8 of the electric machine 3 is connected to a shaft section 50 of the planet carrier 9, which extends axially from a flange section 51 of the planet carrier 9 towards the switching device 5. The largest diameter of the housing 7 is only slightly larger than the largest diameter of the planet carrier 9. At the end of the shaft section 50 is the sleeve extension 15, via which the planet carrier 9 is rotatably mounted in the intermediate wall 44 of the housing 7 by means of the bearing 17. In the present embodiment, the hollow shaft 24 is also correspondingly longer axially due to the axially adjacent arrangement of the planetary gear set and the electric machine.The rotationally fixed connection with the second sun gear 12 is achieved by means of a shaft spline 52. Axial locking is provided by means of an axial retaining ring 53. At the opposite end, the hollow shaft is radially supported or rotatably mounted in the sleeve extension 15 via a bearing 54. Otherwise, the present embodiment corresponds in terms of construction and function to that according to the [reference to be added]. Fig. 1 and Fig. 2, so that, to avoid repetition, reference is made to the description above.

[0049] The Fig. Figure 5 shows a further embodiment of the electric drive arrangement 2 according to the invention. The electric drive arrangement 2 largely corresponds to that shown in the Fig. 1 and Fig. 2, or according to the Fig. 3 and Fig. 4, so that all similarities are referred to in abbreviated form in the description above. Identical or corresponding details are marked with the same reference symbols as in the Fig. 1 to 4.

[0050] As with the embodiments described above, the present electric drive arrangement 2 also comprises an electric machine 3, a planetary gear unit 4, and a controllable switching device 5. A difference lies in the arrangement of the electric machine 3, which in the present embodiment is arranged at a radial distance from the axis of rotation A9 of the planet carrier 9. In other words, the motor axis A3 of the electric motor 3 is arranged with a radial offset from the axis of rotation A9 of the planet carrier 9. This axis offset is bridged by means of a transmission gear unit 60.

[0051] Specifically, the transmission unit comprises a first drive gear 61, which is arranged coaxially with the motor shaft of the electric machine 3 and rigidly connected to it, and an output gear 62, which is arranged coaxially with the planet carrier 9 and rigidly connected to it. It is evident that the output gear 62 has a significantly larger diameter than the drive gear 61, thus providing a reduction in speed. The two gears 61 and 62 are driven by each other and mesh directly with one another. Such transmissions are also known as spur gear transmissions. It is understood, however, that other transmission designs are also possible, in which an axial offset is provided between the input and output sections, such as a chain drive or belt drive.

[0052] The electric machine 3 is arranged axially offset from the planetary gear unit 4 and the switching device 5. Preferably, the axial offset between the motor axis A3 and the planet carrier axis A9 is as small as possible, meaning that the electric machine 3 at least partially radially overlaps the planetary gear unit 4. In the present embodiment, the housing assembly 7 has a motor housing section 41 in which the electric machine 3 is received. The motor housing section 41 is part of the overall housing 7 of the electric drive assembly 2.

[0053] The Fig. Figure 6 shows a further embodiment of the electric drive arrangement 2 according to the invention. The electric drive arrangement 2 largely corresponds to that shown in Figure 6. Fig. 5, so that all similarities are referred to in abbreviated form in the description above. Identical or corresponding details are marked with the same reference symbols as in Fig. 5.

[0054] Another difference lies in the arrangement of the electric machine 3, which in the present embodiment is arranged at an angular offset from the axis of rotation A9 of the planet carrier 9. In other words, the motor axis A3 of the electric motor 3 runs at an angle to the axis of rotation A9 of the planet carrier 9, in particular at a right angle. The two axes of rotation A3 and A9 can intersect or cross at a distance.

[0055] A gear unit 60 in the form of a bevel gear or helical gear is provided, which enables torque transmission with angular displacement of the axes of rotation A3, A9. The bevel gear has a first drive gear 61 in the form of a bevel gear, which is arranged coaxially to the motor shaft of the electric machine 3 and rigidly connected to it, and an output gear 62 in the form of a ring gear, which is arranged coaxially to the planet carrier 9 and rigidly connected to it. The two gears 61, 62 mesh with each other, with the toothing being, in particular, a hypoid gear.

[0056] The electric machine 3 is arranged such that the axis of rotation A3 runs between the planetary gear unit 4 and the switching device 5. However, other arrangements are also conceivable. In the present embodiment, the housing assembly 7 has a motor housing section 41 in which the electric machine 3 is received. The motor housing section 41 is part of the overall housing 7 of the electric drive assembly 2.

[0057] The Fig. Figure 7 shows a further embodiment of an electric drive arrangement 2 according to the invention. The electric drive arrangement 2 is based on the one described in Fig. The electric drive arrangement 2 shown in Figure 2 additionally features an output unit 70. For all similarities, reference is made to the description above. Identical or corresponding details are marked with the same reference numerals as in Figure 2. Fig. 2. The only difference from the embodiment according to Fig. 2 consists in the fact that in the present embodiment according to Fig. 7 an output unit 70 in the form of a differential gear unit is provided, which is described in more detail below.

[0058] The differential gear unit 70 comprises a differential carrier 71 connected to the first sun gear 11, several differential gears 72 rotatably mounted on a journal 73 within the differential carrier 71 and rotating together with the differential carrier 71 about its axis of rotation, and two side gears 74, 74', each rotatably arranged coaxially with the axis of rotation of the differential carrier 71 and meshing with the differential gears 72. Torque introduced into the differential carrier 71 is transmitted via the differential gears 72 to the two side gears 74, 74', with a compensating effect between the two side gears. The side gears 74, 74' are in turn rotationally fixed to the associated output shafts 25, 26, for example via splined shafts, which transmit the introduced torque to the wheels of the vehicle.

[0059] It can be seen that the planetary gear 4 and the differential gear 70 are arranged coaxially and laterally offset from each other. The first sun gear 11 is connected to the differential housing 71 via a hollow shaft 24 in a rotationally fixed manner in order to drive it; that is, the first sun gear 11 and the differential housing 71 rotate together about the axis of rotation A.

[0060] In the first switching position of the switching device 5, the second sun gear 12 is held rotationally fixed, so that the full torque of the electric machine 3 is transmitted via the first sun gear 11 to the differential gear 70. The planetary gear 4 operates like a conventional reduction gear, so that the downstream differential gear 70 rotates at a correspondingly lower speed than the planet carrier 9, corresponding to the reduction ratio of the planetary gear.

[0061] In the second switching position, the second sun gear 12 is rotationally fixed to one of the output shafts 25, 26 of the differential gear unit 70. Thus, the reduction ratio formed by the planetary gear 4 between the differential carrier 71, connected to the first sun gear 11, and the output shaft 425, which is rotationally fixed to the second sun gear 12, is effective. In this switching position, the electric machine operates as a torque vectoring device, which, depending on the motor's direction of rotation, can transmit an additional torque to one of the two output shafts 25, 26 of the differential gear 70. This allows the two output shafts 25, 26, and consequently the connected side shafts, to be driven with different torques. In the third switching position, the electric machine 3 is decoupled from the drive train downstream in the power path.

[0062] The present electric drive arrangement 2 is designed to drive an associated drive train on its own. In other words, it is not intended that any further torque from another drive source be transmitted to this drive train driven by the electric drive arrangement 2. However, in this embodiment, it is possible for a first drive train to be driven by a primary drive source and for a second drive train to be driven by a secondary drive source. The electric drive arrangement 2 according to the invention can be used for the primary and / or the secondary drive train.

[0063] The Fig. Figure 8 shows a drive arrangement with an electric drive arrangement 2 according to the invention in a further embodiment. The electric drive arrangement 2 is based on the one described in Fig. The electric drive arrangement 2 shown in Figure 7 additionally comprises a gear unit 80. For all similarities of the electric drive arrangement 2, reference is made to the description above. Identical or corresponding details are identified by the same reference numerals as in the aforementioned figures.

[0064] The only difference from the embodiment according to Fig. 7 consists in the fact that in the present embodiment according to Fig. 8 A gear unit 80 in the form of a bevel gear is provided, which is described in more detail below. The bevel gear has a drive gear 81 in the form of a bevel gear and a driven gear 82 in the form of a ring gear. The bevel gear 81 can be driven by another drive source, for example an internal combustion engine, in particular via a longitudinal drive shaft (not shown). The ring gear 82 is arranged coaxially with the differential carrier 71 and is rigidly connected to it.

[0065] The gear unit 80 serves as an additional input for introducing torque into the differential housing 71, which is then distributed by the differential gear to the two output shafts 25, 26. In other words, the drive arrangement shown comprises two inputs through which torque can be introduced: the first sun gear 11, through which torque from the electric machine 3 can be introduced into the differential housing 71, and the ring gear 82, through which torque from the other drive source (not shown) can be introduced into the differential housing 71.

[0066] This design allows for various operating modes. For example, in a first operating mode, when the switching device 5 is in the first switching position, the torque introduced into the differential 70 by the first drive source (internal combustion engine) can be increased by the electric machine 3. This allows for a temporary increase in drive torque to be available in the vehicle's drive system, for example, during acceleration. In a second operating mode, when the switching device 5 is in the second switching position, the torque introduced into the differential 70 by the first drive source via the drive shaft 83 and the bevel gear 80, and distributed evenly between the two output shafts 25 and 26, can be increased by the electric machine 3, if required, by imposing an additional torque on one of the two output shafts 25 and 26.For example, when cornering, a wheel on the outside of the curve can be driven with a greater torque than a wheel on the inside. Furthermore, the differential 70 can operate as an open differential when the shift mechanism is open, i.e., in the third shift position.

[0067] The present electric drive arrangement 2 is designed for superimposed driving of an associated drive train. In other words, it is intended that a further torque from another drive source can be transmitted to this drive train, which is driven by the electric drive arrangement 2.

[0068] The Fig. Figure 9 shows a drive arrangement 90 with an electric drive arrangement 2 according to the invention in a further embodiment. The electric drive arrangement 2 corresponds to the one shown in Fig. The electric drive arrangement 2 shown in Figure 4 is described in abbreviated form. Identical components are designated with the same reference numerals as in Figure 4. Fig. 4.

[0069] The drive assembly 90 serves to drive a drive axle of a motor vehicle, in particular the front axle, or also the rear axle. It can be seen that the drive assembly 90 comprises a transversely extending internal combustion engine 91 as the primary drive source, a disconnect clutch 92, a multi-stage gearbox 93, and a differential 70 for distributing the torque to the two output shafts 25, 26 or side shafts. The electric drive assembly 2 is connected to the differential 70 and is drive-connected to the differential housing 71. In this respect, the assembly consisting of the electric drive assembly 2 and the differential 70 is functionally structured like the one described in Fig. Arrangement shown in section 8.

[0070] The present drive arrangement 90 therefore comprises two drive sources, namely the internal combustion engine 91 and the electric machine 3, which can each drive the differential gear 70 and the associated side shafts of the drive axle individually or together superimposed.

[0071] This design enables the operating modes of the electric drive arrangement 2 described above. In the first switching position, an additional torque can be applied by the electric motor 3 to the torque introduced by the internal combustion engine 91 into the differential gear 70. In the second switching position of the switching device 5, a torque introduced by the internal combustion engine 91 into the differential gear 70 via the step-through transmission 93 can be variably distributed to the two output shafts 25, 26 by means of the electric motor 3, if required. Alternatively, depending on the direction of rotation of the electric motor 3, an additional torque can be applied to one of the two output shafts 25, 26, so that different torques are present at the two output shafts 25, 26. In the third switching position, the differential gear can operate as an open differential.

[0072] The Fig. Figure 10 shows a drive arrangement 90 with an electric drive arrangement 2 according to the invention in a further embodiment. The present drive arrangement 90 largely corresponds to that according to [reference to relevant figure]. Fig. 9, so that all similarities are referred to in abbreviated form by reference to the description above. Identical or corresponding details are marked with the same reference symbols as in Fig. 9.

[0073] The only difference is that the electric drive arrangement 2 in the present embodiment is arranged according to the Fig. The embodiment shown in Figure 5 is designed with a parallel-offset electric machine 3, the description of which is abbreviated hereby referenced. Otherwise, the drive arrangement 90 corresponds to the following: Fig. 10 of those according to Fig. 9, so that with regard to all similarities reference is made to the above description.

[0074] The Fig. Figure 11 shows a drive arrangement 90 with an electric drive arrangement 2 according to the invention in a further embodiment. The present drive arrangement largely corresponds to that according to the Fig. 9 and Fig. 10, so that all similarities are referred to in abbreviated form by reference to the description above. Identical or corresponding details are marked with the same reference symbols as in Fig. 10.

[0075] The only difference is that the electric drive arrangement 2 in the present embodiment is arranged according to the Fig. The embodiment shown in Figure 6 is designed with an angularly offset electric machine 3, the description of which is abbreviated hereafter. Otherwise, the drive arrangement 90 corresponds to the following: Fig. 11 of those according to Fig. 9, so that with regard to all similarities reference is made to the above description.

[0076] The described electric drive arrangements 2 offer the possibility of being used, depending on requirements, both as an additional drive source for propelling the vehicle and as a torque vectoring device for asymmetrical torque distribution between two output shafts. This results in expanded drive options for powertrain concepts with such an electric drive arrangement, while maintaining a compact design. Reference symbol list 2 Electric drive arrangement 3 electric machine 4 planetary gear unit 5 Switching device 6 Stator 7. stationary component / housing 8 Rotor 9 planetary carriers 10 planetary gear 11 first sun wheel 12 second sun wheel 13 Recording section 14, 15 sleeve attachments 16 warehouses 17 warehouses 18 radial bearings 19 cones 20 axial bearings 21 Gear section 22 Gear section 23 Fasteners 24 Hollow shaft 25 Output shaft 26 Output shaft 27 Shaft seal 28 Shaft seal 29 axial bearings 30 Sleeve section / hollow shaft 32 Switching element 33 Coupling element 34 Contouring agents 35 Contouring agents 36 Intermediate element 37 cones 38 Longitudinal toothing 39 retaining ring 40 Housing section 42 Housing section 43 screw connections 44 Partition wall 45 warehouses 46 Shaft seal 50 wave section 51 Flange section 52 Shaft teeth 53 Axial retaining ring 54 warehouses 60 Gear unit 61 Drive wheel 62 Output gear 70 Output unit / differential gear unit 71 Differential basket 72 differential gears 73 cones 74, 74' Side shaft wheel 80 Gear unit 81 Drive wheel 82 Output gear 83 Drive shaft 90 Drive arrangement 91 Drive source 92 Disconnect coupling 93-stage gearbox A axis of rotation

Claims

[1] Electric drive arrangement for propelling a motor vehicle, comprising: an electric machine (3) for generating a driving torque, a planetary gear unit (4) for transmitting the drive torque to an output unit (70), and a switching device (5) for the planetary gear unit, wherein the planetary gear unit (4) comprises a planet carrier (9) which is driven by the electric machine (3) to rotate about a rotary axis (A9), several planet gears (10) rotating with the planet carrier (9) and two sun gears (11, 12), wherein the planet gears (10) each have a first toothed section (21) and a second toothed section (22), wherein a first of the two sun gears (11, 12) is drive-connected to the first toothed sections (21) of the planet gears (10) and is designed as an output part for driving a downstream output unit (70), and wherein a second of the two sun gears (12, 11) is drive-connected to the second toothed sections (22) of the planet gears (10) and is operatively connected to the switching device (5) in such a way that the second sun gear (12) is supported in a first switching position on a stationary component (7) in the direction of rotation, and in a second switching position is non-rotatably connected to a first output shaft (25) of the output unit (70) driven by the first sun gear (11). [2] Electric drive arrangement according to claim 1, characterized by , that the switching device (5) can be moved into a third switching position in which the second sun gear (12) can rotate freely. [3] Electric drive arrangement according to one of claims 1 or 2, characterized by, that the switching device (5) has a controllable switching element (32) and a coupling element (33) movable by the switching element (32), wherein the coupling element (33) is connected to the stationary component (7) in a rotationally fixed manner in the first switching position and is connected to the first output shaft (25) in a rotationally fixed manner in the second switching position. [4] Electric drive arrangement according to claim 3, characterized by , that the coupling element (33) is connected to the second sun gear (12) in a rotationally fixed and axially movable manner. [5] Electric drive arrangement according to one of claims 1 to 4, characterized by , that the output unit (70) driven by the first sun gear (11) is designed in the form of a differential gear unit, wherein the differential gear unit has a differential basket (71) connected to the first sun gear (11) for drive, several differential gears (72) rotating with the differential basket (71) and two side shaft gears (74, 74') meshing with the differential gears (72), wherein a first of the two side shaft gears (74, 74') is non-rotatably connected to the first output shaft (25), and wherein a second of the two side shaft gears (74', 74) is connected to a second output shaft (26) in a rotationally fixed manner. [6] Electric drive arrangement according to claim 5, characterized by , that the planet carrier (9) and the differential basket (71) are arranged coaxially to each other and axially offset from each other. [7] Electric drive arrangement according to one of claims 5 or 6, characterized by , that the differential basket (71) has a further input part (82) for introducing a torque from another drive source. [8] Electric drive arrangement according to any one of claims 1 to 7, characterized by , that the planet carrier (9) of the planetary gear unit (4) is designed in a basket-like manner and has two sleeve attachments (14,15) for the two-sided support of the planet carrier (9) in a housing (7). [9] Electric drive arrangement according to one of claims 1 or 8, characterized by , that the electric machine (3) is arranged coaxially to the planetary gear unit (4), wherein a rotor (8) of the electric machine (3) is drive-connected to the planet carrier (9) of the planetary gear unit (4). [10] Electric drive arrangement according to claim 9, characterized by , that the electric machine (3) is arranged radially outside the planetary gear unit (4) with axial overlap, wherein the rotor (8) of the electric machine (3) is connected to a shell section of the planet carrier (9) in a rotationally fixed manner. [11] Electric drive arrangement according to claim 9, characterized by, that the electric machine (3) is arranged with axial offset and radial overlap to the planetary gear unit (4), wherein the rotor (8) of the electric machine (3) is connected in a rotationally fixed manner to a sleeve extension (50) of the planet carrier (9). [12] Electric drive arrangement according to any one of claims 1 to 8, characterized by , further comprising a transmission unit (60) arranged in the power path between the electric machine (3) and the planetary gear unit (4), wherein the transmission unit (60) is in particular designed to compensate for an axis offset between a motor rotation axis (A3) of the electric machine (3) and the rotation axis (A9) of the planet carrier (9), wherein the electric machine (3) may in particular be arranged with an axial offset and / or with an angular offset to the planetary gear unit (4). [13] Electric drive arrangement according to one of claims 1 to 12, characterized by, that the housing (7) is designed in multiple parts and has a housing section (42) in which the switching device (5) is accommodated and a housing section (40) in which the planetary differential unit (4) is accommodated. [14] Drive train arrangement with an electric drive arrangement according to any one of claims 1 to 13, comprising: a first drive axis which can be driven in a rotary manner by a first drive source, and a second drive axis which can be driven in a rotary manner by the electric drive arrangement (2), wherein the first drive axis and the second drive axis are mechanically unconnected, wherein the second drive axle has a differential gear unit (70) with a differential basket (71) and two output shafts (2, 26), wherein the differential basket (71) is drive-connected to the electric machine (3), wherein in the first switching position of the electric drive arrangement (2) a torque can be introduced from the electric machine (3) to the differential basket (71) of the differential gear unit (70) to drive the second drive axle, which is distributed evenly to the two output shafts (25, 26) via the differential basket (71), and in the second switching position a drive torque can be generated by the electric machine (3) between the differential basket (71) and one of the two output shafts (25, 26). [15] Drive train arrangement with an electric drive arrangement according to any one of claims 1 to 13, comprising: a first drive axis which can be driven by a first drive train from a first drive source, a second drive axis which can be driven by a second drive train from the first drive source and which is connected to the electric drive arrangement (2) in a drive connection, wherein the second drive axle has a differential gear unit (70) with a differential basket (71) and two output shafts (2, 26), wherein the differential basket (71) is drive-connected to the electric machine (3) and the first drive source, wherein in the first switching position of the electric drive arrangement (2) an additional torque can be introduced from the electric machine (3) onto the differential basket (71) of the differential gear unit (70) to drive the second drive axle, and in the second switching position a drive torque can be generated from the electric machine (3) between the differential basket (71) and one of the two output shafts (25, 26), which is superimposed on a torque that can be introduced from the first drive source into the differential basket (71). [16] Powertrain arrangement comprising a first power source (91), in particular an internal combustion engine, a stepped gear unit (93) downstream of the first power source in the power path, and a differential gear unit (70) downstream of the stepped gear unit (93) in the power path, comprising a differential basket (71) and two output shafts (25, 26), and an electric drive arrangement (2) according to any one of claims 1 to 13, wherein the differential basket (71) of the differential gear unit (70) is connected to the stepped gear unit (93) and to the planetary gear unit (4) in a drive-connected manner, such that in the first switching position of the electric drive arrangement (2) an additional torque can be introduced from the electric machine (3) onto the differential basket (71), and in the second switching position a drive torque can be generated from the electric machine (3) between the differential basket (71) and one of the two output shafts (25, 26),which is superimposed on a torque that can be introduced into the differential basket (71) from the first drive source (91).

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