Drive unit

Abstract

A drive unit includes a drive shaft, an electric machine for electrically generating a drive torque, a motor shaft for transmitting the drive torque, and a continuously variable transmission designed as a belt-driven conical disk transmission. The belt-driven conical disk transmission includes an input disk set coupled to the motor shaft, an output disk set coupled to the drive shaft, and a traction means for coupling the input disk set to the output disk set. The output disk set includes an output-side fixed disk that is axially immovable relative to the drive shaft, and an output-side floating disk unit with an output-side floating disk that is axially displaceable relative to the drive shaft to vary a first axial distance between the output-side floating disk and the output-side fixed disk. The output-side floating disk unit is arranged at least partially in a common axial area with the electric machine.

Claims

1.-10. (canceled)

11. A drive unit for electrically driving a motor vehicle, comprising: a drive shaft for driving a drive wheel; an electric machine for electrically generating a drive torque; a motor shaft arranged substantially axially parallel to the drive shaft for transmitting the drive torque; and a continuously variable transmission designed as a belt-driven conical disk transmission, the belt-drive conical disk transmission comprising: an input disk set coupled to the motor shaft; an output disk set coupled to the drive shaft, comprising: an output-side fixed disk that is axially immovable relative to the drive shaft; and an output-side floating disk unit comprising an output-side floating disk that is axially displaceable relative to the drive shaft to vary a first axial distance between the output-side floating disk and the output-side fixed disk; and a traction means for coupling the input disk set to the output disk set, wherein the output-side floating disk unit is arranged at least partially in a common axial area with the electric machine.

12. The drive unit of claim 11 wherein the traction means is a V-belt.

13. The drive unit of claim 11, wherein the electric machine comprises: an electrically operable stator comprising: a support; and current-flowing stator windings provided in the support; and a rotor connected to the motor shaft, wherein the output-side floating disk unit is at least partially arranged in a common axial area with: the support; or the current-flowing stator windings.

14. The drive unit of claim 13 wherein the support is an iron core.

15. The drive unit of claim 13, wherein: the current-flowing stator windings comprise end windings that axially protrude from the support; and the output-side floating disk unit is arranged at least partially in a common axial area with the end windings.

16. The drive unit of claim 11, wherein: the output-side floating disk unit comprises a housing for guiding the output-side floating disk; and at least a part of the housing is arranged in a common axial area with the electric machine.

17. The drive unit of claim 11, wherein: the input disk set comprises: an input-side fixed disk that is axially immovable relative to the motor shaft; and an input-side floating disk unit comprising an input-side floating disk that is axially displaceable relative to the motor shaft to vary a second axial distance between the input-side floating disk and the input-side fixed disk; and the input-side floating disk unit is provided on an axial side of the input disk set facing away from the electric machine.

18. The drive unit of claim 17, wherein: the output disk set is indirectly coupled to the drive shaft via a reduction stage; and the reduction stage is arranged at least partially in a common axial area with the input disk set.

19. The drive unit of claim 18, wherein the reduction stage is arranged at least partially in a common axial area with the input-side floating disk unit.

20. The drive unit of claim 17, wherein: the output disk set is indirectly coupled to two drive shafts via a differential gear; each of the two drive shafts leads to a respective drive wheel; and the differential gear is arranged at least partially in a common axial area with the input disk set.

21. The drive unit of claim 20 wherein the differential gear is arranged at least partially in a common axial area with the input-side floating disk unit.

22. The drive unit of claim 11, wherein: the output disk set is indirectly coupled to the drive shaft via a reduction stage; and the reduction stage is arranged at least partially in a common axial area with the input disk set.

23. The drive unit of claim 11, wherein: the output disk set is indirectly coupled to two drive shafts via a differential gear; each of the two drive shafts leads to a respective drive wheel; and the differential gear is arranged at least partially in a common axial area with the input disk set.

24. The drive unit of claim 11, wherein the output disk set is arranged coaxially to the drive shaft.

25. The drive unit of claim 24, wherein the output disk set comprises a hollow shaft connected to the output-side fixed disk for passage of the drive shaft.

26. The drive unit of claim 11, wherein: the input disk set is arranged coaxially to the motor shaft; the input disk set has a hollow shaft connected to an input-side fixed disk for passage of the motor shaft; and the input disk set is indirectly coupled to the motor shaft via a pre-reduction stage.

27. The drive unit of claim 26, wherein the pre-reduction stage is arranged at least partially in a common axial area with a reduction stage or a differential gear provided in a torque flow between the output disk set and the drive shaft.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In the following, the disclosure is explained by way of example with reference to the accompanying drawings using exemplary embodiments, in which the features shown below can represent an aspect of the disclosure both individually and in combination. In the figures:

[0022] FIG. 1 shows a schematic diagram of a first embodiment of a drive unit;

[0023] FIG. 2 shows a schematic diagram of a second embodiment of a drive unit; and

[0024] FIG. 3 shows a schematic section view of the drive unit from FIG. 1.

DETAILED DESCRIPTION

[0025] The drive unit 10 of an electrically drivable motor vehicle illustrated in FIG. 1 and FIG. 3 has an electric machine 12 with a stator 14 and a rotor 16. The rotor 16 can have a support 17 which has a smaller axial extension than the rotor 16 and in which stator windings through which current flows are embedded. The stator windings can have end windings 18 protruding from the support 17 in the axial direction. The rotor 16 is connected in a rotationally fixed manner to a motor shaft 20, which in turn is coupled to an input disk set 24 of a continuously variable transmission 26 configured as a belt-driven conical disk transmission.

[0026] The input disk set 24 has an input-side fixed disk 30 connected in a rotationally fixed manner to the motor shaft 20 and an input-side floating disk unit 32. The input-side floating disk unit 32 has an input-side floating disk 34 which is axially displaceable relative to the input-side fixed disk 30 and which, with the aid of a hydraulic pressure built up in an input-side pressure chamber 36, can be displaced against the spring force of a restoring spring, in order to displace a traction means 38, designed to be pressed between the input-side fixed disk 30 and the input-side floating disk 34 as a V-belt for continuously changing a transmission ratio of the continuously variable transmission 26 to a different effective radius.

[0027] An output disk set 40 is coupled to the input disk set 24 via the traction means 38. The output disk set 40 has an output-side fixed disk 44 connected to an output-side hollow shaft 42 and an output-side floating disk unit 46. An output-side floating disk unit 46 has an output-side floating disk 48 which is axially displaceable relative to the output-side fixed disk 44 and which can press the traction means 38 between the output-side fixed disk 44 and the output-side floating disk 48. The output-side hollow shaft 42 is coupled via a reduction stage 50 designed as precisely one planetary gear to a differential gear 52, from which two drive shafts 54 extend. A drive wheel 56 is coupled to each drive shaft 54.

[0028] The input-side floating disk unit 32 and the output-side floating disk unit 46 are provided on different sides of the continuously variable transmission 26, and the electric machine 12 is positioned adjacent to the input-side fixed disk 30. As a result, the output-side floating disk unit 46 can be arranged with at least one housing 58 in a common axial area with the electric machine 12 in a space-saving manner. At least the housing 58 and the end windings 18 protruding from the support 17 of the stator 14 can be arranged at least partially in a common axial area, so that, in a plane including the motor shaft 20 and the drive shaft 54 viewed in the radial direction, part of the output-side floating disk unit 46 and a part of the electric machine 12 overlap.

[0029] In the embodiment of the drive unit 10 shown in FIG. 2, in comparison to the embodiment of the drive unit 10 shown in FIG. 1, a pre-reduction stage 22 is provided on the input side between the motor shaft 20 and the input disk set 24. For this purpose, the motor shaft 20 is coupled via the pre-reduction stage 22 to an input-side hollow shaft 28 of the input disk set 24, through which the motor shaft 20 is passed. The input-side hollow shaft 28 is connected to an output of the pre-reduction stage 22 configured as precisely one planetary gear and the input-side fixed disk 30. The pre-reduction stage 22 is arranged in a common axial area with the reduction stage 50 and/or the differential gear 52 in an installation space-saving manner.

REFERENCE NUMERALS

[0030] 10 Drive unit

[0031] 12 Electric machine

[0032] 14 Stator

[0033] 16 Rotor

[0034] 17 Support

[0035] 18 End windings

[0036] 20 Motor shaft

[0037] 22 Pre-reduction stage

[0038] 24 Input disk set

[0039] 26 Continuously variable transmission

[0040] 28 Input-side hollow shaft

[0041] 30 Input-side fixed disk

[0042] 32 Input-side floating disk unit

[0043] 34 Input-side floating disk

[0044] 36 Input-side pressure chamber

[0045] 38 Traction means

[0046] 40 Output disk set

[0047] 42 Output-side hollow shaft

[0048] 44 Output-side fixed disk

[0049] 46 Output-side floating disk unit

[0050] 48 Output-side floating disk

[0051] 50 Reduction stage

[0052] 52 Differential gear

[0053] 54 Drive shaft

[0054] 56 Drive wheel

[0055] 58 Housing