Electric drive for a motor vehicle

Patent metadata

Field	Value
Publication number	US-9435415-B2
Application number	US-201514693931-A
Country	US
Kind code	B2
Filing date	Apr 23, 2015
Priority date	Jul 13, 2010
Publication date	Sep 6, 2016
Grant date	Sep 6, 2016

Abstract

An electric drive for a motor vehicle comprises a first gear stage, driveable by the electric motor, a second gear stage, driveable by the first gear stage, and a differential drive, driveable by the second gear stage. The first gear stage has a driving wheel and an output wheel, wherein the driving wheel is arranged coaxially to the output shaft of the electric motor and is rotatingly driveable by the electric motor around a first rotational axis A. The output wheel is drivingly connected to the driving wheel and is rotatingly driveable around a second rotational axis B, wherein the second rotational axis B is arranged parallel off-set to the first rotational axis A. The second gear stage and the differential drive are arranged coaxially to the second rotational axis B.

First claim

The invention claimed is:

1. An electric drive for a motor vehicle, comprising:
an electric motor and a drive unit, wherein the electric motor comprises an output shaft which is rotatingly drivable around a first rotational axis (A);
wherein the drive unit has a first gear stage that is driveable by the electric motor, a second gear stage that is driveable by the first gear stage, and a differential drive that is driveable by the second gear stage;
wherein the first gear stage comprises a driving wheel and an output wheel, wherein the driving wheel and the output wheel are drivingly connected to each other with a fixed transmission ratio, wherein the driving wheel is directly connected to the output shaft of the electric motor in a rotationally fixed way and is rotatingly driveable by the electric motor around the first rotational axis (A), and wherein the output wheel is rotatingly driveable around a second rotational axis (B);
wherein the second rotational axis (B) is arranged so as to be parallel off-set to the first rotational axis (A);
wherein the second gear stage comprises a planetary drive with an input element drivingly connected to the output wheel of the first gear stage, and an output element drivingly connected to the differential drive; and
wherein the input element and the output element of the second gear stage as well as the differential drive are arranged coaxially to the second rotational axis (B);
the electric drive further comprising a housing with a first housing portion and a second housing portion connected to each other, and a hollow shaft extending from the first housing portion into the second housing portion;
wherein the first gear stage is arranged in the first housing portion,
the second gear stage and the differential drive are arranged in the second housing portion, and
the output wheel of the first gear stage is rotationally fixed to a first portion of the hollow shaft arranged in the first housing part, and the input element of the second gear stage is rotationally fixed to a second portion of the hollow shaft arranged in the second housing portion.

2. The electric drive according to claim 1 , wherein the first gear stage comprises a reduction drive that is formed as one of a belt drive, a chain drive, and a spur gear drive.

3. The electric drive according to claim 1 , wherein the second gear stage comprises a planetary drive with a ring gear, a sun gear, a plurality of planetary gears, and a planet carrier, wherein, one of the sun gear and the ring gear forms the input element that is rotatingly driveable by the output wheel of the first gear stage around the second rotational axis (B).

4. The electric drive according to claim 3 , wherein the sun gear forms the input element drivingly connected to the output wheel of the first gear stage, and the ring gear is one of supported and supportable against rotation on a first stationary component, and wherein the planet carrier forms the output element of the second gear stage that is drivingly connected to the differential drive.

5. The electric drive according to claim 4 , wherein, between the ring gear of the planetary drive and the stationary component, an externally controllable clutch assembly is provided that is configured to selectively at least one of connect the ring gear to the stationary component and release the ring gear from the stationary component.

6. The electric drive according to claim 5 , wherein an actuating device for actuating the clutch assembly is provided.

7. The electric drive according to claim 5 , wherein the planetary drive has a first planetary gear stage with a first transmission ratio between the input element and the output element, and a second planetary gear stage with a second transmission ratio between the input element and the output element.

8. The electric drive according to claim 7 , wherein the clutch assembly is formed for the ring gear of the first planetary gear stage and the ring gear of the second planetary gear stage to selectively be one of supported on the stationary component against rotation and disconnected.

9. The electric drive according to claim 8 , wherein:
the clutch assembly comprises a switching clutch that is transferable at least into a first switching position and into a second switching position, wherein, in the first switching position of the switching clutch, the ring gear of the first planetary gear stage is connected to the stationary component, and the ring gear of the second planetary gear stage can rotate freely relative to the stationary component, and
wherein, in the second switching position of the switching clutch, the ring gear of the first planetary gear stage is freely rotatable relative to the stationary component, and the ring gear of the second planetary gear stage is connected to the stationary component.

10. The electric drive according to claim 9 , wherein the switching clutch is transferable into a third switching position in which the first ring gear and the second ring gear are freely rotatable relative to the stationary component.

11. The electric drive according to claim 8 , wherein:
the clutch assembly comprises a first friction clutch that is arranged between the ring gear of the first planetary gear stage and the stationary component, and
a second friction clutch that is arranged between the ring gear of the second planetary gear stage and the stationary component.

12. The electric drive according to claim 11 , wherein the first and the second friction clutch are each variably controllable between an open position, in which a torque transmission is interrupted, and a closed position, in which torque is transmitted.

13. The electric drive according to claim 11 , wherein, for each of the first friction clutch and the second friction clutch, a separate actuating unit is provided by which the corresponding friction clutch is individually actuatable.

14. The electric drive according to claim 3 , wherein the differential drive has a differential carrier that is rotatingly driveable by the planet carrier around the second rotational axis (B).

15. The electric drive according to claim 14 , wherein the planetary drive and the differential drive are arranged axially next to each other.

16. The electric drive according to claim 14 , wherein the output element of the planetary drive and the differential carrier of the differential drive are connected to each other in a rotationally fixed way and jointly rotate around the second rotational axis (B).

17. The electric drive according to claim 1 , wherein the input element of the planetary drive and the output wheel of the first gear stage are connected to each other in a rotationally fixed way and jointly rotate around the second rotational axis (B).

18. The electric drive according to claim 1 ,
wherein an opening between the first housing portion and the second housing portion, through which the hollow shaft extends, is sealed by a sealing ring;
an interior of the first housing portion is lubricant-free; and an interior of the second housing portion is at least partially filled with lubricant.

Assignees

• Gkn Driveline Int Gmbh

Inventors

• Gassmann Theodor

Classifications

• F16H37/082 Primary

  and additional planetary reduction gears · CPC title

• F16H2200/0021

  specially adapted for electric vehicles · CPC title

• B60K1/00 Primary

  Arrangement or mounting of electrical propulsion units (B60K7/00 takes precedence; arrangement or mounting of plural diverse prime-movers for mutual or common propulsion B60K6/00) · CPC title

• F16H37/02

  comprising essentially only toothed or friction gearings · CPC title

• B60K2001/001

  one motor mounted on a propulsion axle for rotating right and left wheels of this axle · CPC title