VEHICLE WITH RIGID REAR AXLE DIRECT ELECTRIC DRIVE

Abstract

A vehicle includes a body, an internal combustion engine, a traction battery, a front axle connecting two front wheels with at least one of the two front wheels drivingly coupled to the internal combustion engine, a rear axle connecting two rear wheels and carried by two leaf spring units, each leaf spring unit being pivotably connected at one end to the body and at another end to a connection arm pivotably connected to the body, wherein the rear axle includes two driveshafts connecting the rear wheels, and a drive unit supported by the rear axle to be self-supporting relative to the body. The drive unit includes an electric motor coupled to the traction battery and a differential mechanically coupled to the two driveshafts and the electric motor. The rear axle is mechanically uncoupled from the internal combustion engine.

Claims

1. A vehicle comprising: a body; an internal combustion engine; a traction battery; a front axle connecting two front wheels with at least one of the two front wheels drivingly coupled to the internal combustion engine; a rear axle connecting two rear wheels and carried by two leaf spring units, each leaf spring unit being pivotably connected at one end to the body and at another end to a connection arm pivotably connected to the body, wherein the rear axle includes two driveshafts connecting the rear wheels; and a drive unit supported by the rear axle to be self-supporting relative to the body, the drive unit comprising: an electric motor coupled to the traction battery; and a differential mechanically coupled to the two driveshafts and the electric motor.

2. The vehicle of claim 1 further comprising a drive housing containing the electric motor and the differential.

3. The vehicle of claim 2 further comprising two shaft housings connected to the drive housing, each shaft housing associated with, and at least partly containing, one of the two driveshafts.

4. The vehicle of claim 1 further comprising a second traction battery coupled to the electric motor, wherein the traction battery and the second traction battery are position on opposite sides of a longitudinal centerline of the vehicle.

5. The vehicle of claim 1 further comprising a generator mechanically coupled to the internal combustion engine and electrically coupled to the traction battery.

6. The vehicle of claim 1 wherein the drive unit further comprises a coupling to selectively disconnect the two driveshafts from the electric motor.

7. The vehicle of claim 1 wherein the drive unit comprises a first gear connected to the electric motor and a second gear coupling the first gear to the differential.

8. The vehicle of claim 7 wherein the second gear comprises a reduction gear.

9. The vehicle of claim 1 wherein the rear axle is mechanically uncoupled from the internal combustion engine.

10. A vehicle comprising: a body; a rear axle carried by two leaf spring units, each leaf spring unit pivotably connected to the body and to a connection arm pivotably connected to the body; two driveshafts within the rear axle; and a drive unit having a differential coupled to the two driveshafts and to an electric motor, wherein the drive unit is carried by the rear axle to be self-supporting relative to the body.

11. The vehicle of claim 10 further comprising: a front axle; and an internal combustion engine coupled to the front axle and mechanically uncoupled from the rear axle.

12. The vehicle of claim 11 further comprising a traction battery coupled to the electric motor.

13. The vehicle of claim 12 further comprising a generator coupled to the internal combustion engine and electrically coupled to the traction battery.

14. The vehicle of claim 12 further comprising a second traction battery coupled to the electric motor, wherein the traction battery and the second traction battery are positioned on opposite sides of a longitudinal center line of the vehicle.

15. The vehicle of claim 10 wherein the drive unit comprises a coupling to selectively disconnect at least one of the two driveshafts from the electric motor.

16. The vehicle of claim 10 wherein the drive unit comprises: a first gear connected to the electric motor; and a second gear coupling the first gear to the differential, wherein the second gear is a reduction gear.

17. A vehicle comprising: an engine drivingly coupled to a front axle; a rear axle coupled to a vehicle body by two leaf spring units and having two driveshafts; and an electric motor coupled by a differential to the two driveshafts, wherein the electric motor is supported by the rear axle to be self-supporting relative to the vehicle body, wherein the engine is mechanically uncoupled from the rear axle.

18. The vehicle of claim 17 further comprising a traction battery coupled to the electric motor.

19. The vehicle of claim 17 further comprising a first gear connected to the electric motor, and a second gear coupled to the first gear and the differential.

20. The vehicle of claim 17 further comprising a coupling configured to selectively disconnect the electric motor from the two driveshafts.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 shows a schematic side view of a motor vehicle according to one or more embodiments;

[0028] FIG. 2 shows a schematic lower view of the vehicle from FIG. 1; and

[0029] FIG. 3 shows a schematic sectional representation of a drive unit of the vehicle from FIG. 1.

DETAILED DESCRIPTION

[0030] As required, detailed embodiments are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary and may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the claimed subject matter.

[0031] In the different figures, the same parts are provided with the same reference numbers, which is why they are also usually described only once.

[0032] FIGS. 1 and 2 show different views of a motor vehicle 40 according to one embodiment, for example a van. The representation in this case is highly schematic and simplified. A rear axle 1 configured as a rigid axle which extends parallel to the Y-axis is fastened to two leaf springs 4 extending substantially in the direction of the X-axis, via which the rear axle 1 is fastened in a spring-mounted manner to a vehicle body 41, for example a vehicle chassis. The leaf springs 4 which are configured as semi-elliptical springs in the present case may, in particular, be made of spring steel or, where appropriate, of fiber-reinforced plastic. In the present case, they form leaf spring units which may also, alternatively, be configured as assemblies of multiple leaf springs. The rear axle 1 connects two wheels 2 arranged on either side.

[0033] At a front end 4.1, each leaf spring 4 is pivotably connected to the vehicle body 41. At a rear end 4.2, the leaf spring 4 in each case is pivotably connected to a connection arm 5 which, in turn, is pivotably connected to the vehicle body 41. In this case, the body shown therefore corresponds to a Hotchkiss drive. Overall, the connection arms 5 allow movement of the rear end 4.2 within the X-Z plane, to be more precise, a rotation about the pivot axis of the connection arm 5 with respect to the vehicle body 41, as a result of which the deformation of the leaf springs 4 during compression can be balanced.

[0034] The rear axle 1 has two drive shafts 6 for the two wheels 2 and also a drive unit 10 which is depicted as a detail in the sectional representation in FIG. 3. The representation in FIG. 3 is also highly schematic in this case. The drive unit 10 has a drive housing 11 which is used to protect various components from mechanical damage, dirt and moisture. An electric motor 12 is arranged within the housing 11 which interacts via a first gearwheel 13 with a second gearwheel 15 of a transmission gearing. The second gearwheel 15 in turn transmits the driving force of the electric motor 12 to a differential 14 which is configured as a bevel gear differential in the present case. By means of the differential 14, the driving force is transmitted to the respective drive shafts 6 which are rotatably arranged in shaft housings 7 which are connected to the drive housing 11. The drive shafts 6 can be uncoupled from the electric motor 12 via a coupling 16 and are then located to some extent in a self-supporting manner. The entire drive unit 10 is arranged on the rear axle 1 and is movable therewith in respect of the vehicle body 41 according to the spring deflection. In other words, the drive unit 10 is self-supporting with respect to the vehicle body 41.

[0035] The energy supply of the electric motor 12 is guaranteed via two first lines 21 which are connected to two battery units 20. The battery units 20 are arranged separately from the drive unit 10 on or within the vehicle body 41 and are therefore part of the sprung mass. Each battery unit 20 contains one or multiple storage batteries and is therefore rechargeable. The charging of the battery units 20 in this case may take place via two lines 22, on the one hand, which are fed by a generator 24 which is mechanically coupled to an internal combustion engine 23 of the motor vehicle 40. Normally, in addition, possibly also alternatively, for charging by the generator 24, the electric motor 12 can be operated as a generator during braking actions, for example, and electrical energy can be fed to the battery units 20 via the first lines 21. Apart from possible charging of the battery units 20, the internal combustion engine 23 is used as a mechanical drive for the wheels 31 of a front axle 30 of the motor vehicle 40. While it can indirectly (via the generator 24, the battery units 20 and the electric motor 12) provide energy for driving the rear axle 1, the rear axle 1 is mechanically uncoupled from the internal combustion engine 23.

[0036] Overall, running the vehicle 40 with four-wheel drive by means of the internal combustion engine 23 and also the electric motor 12 is possible. The electric motor 12 in this case may, for example, provide additional torque from time to time. It is of course also conceivable here for only the internal combustion engine 23 or also only the electric motor 12 to be occasionally used as the drive. The electric motor 12 may also be used for motor or generator braking of the wheels 2 on the rear axle 1.

[0037] Within the framework of the claimed subject matter, different variants of the embodiment shown in this case are conceivable. For example, the internal combustion engine 23 and the generator 24 could be completely dispensed with and the electric motor 12 could represent the single drive of the vehicle 40. In this case, the battery units 20 could, where necessary, be charged by connecting to a mains power supply. It would also be possible for the internal combustion engine 23 to be mechanically uncoupledtemporarily or permanentlyfrom the wheels 31 of the front axle 30 and only used for energy generation via the generator 24. In addition, it would be possible for the battery units 20 to be dispensed with and the generator 24 directly coupled to the electric motor 12.

[0038] While representative embodiments are described above, it is not intended that these embodiments describe all possible forms of the claimed subject matter. The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the claimed subject matter.