Drive device for all-wheel-drive motor vehicles

Patent metadata

Field	Value
Publication number	US-9758036-B2
Application number	US-201414896188-A
Country	US
Kind code	B2
Filing date	Jun 5, 2014
Priority date	Jun 7, 2013
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

A drive device for all-wheel-drive motor vehicles, includes a primary axle driven by a drive unit via an axle differential and a secondary axle driven via the left and right output elements of the axle differential and via transmitting means. The transmitting means are formed by at least two switching elements, which are arranged coaxial to the axle differential of the primary axle and which act on the left and right drive shaft of the secondary axle via belt or chain transmissions.

First claim

The invention claimed is:

1. A drive device for a four-wheel drive motor vehicle, comprising:
a primary axle driven by a drive aggregate via an axle differential; and
a secondary axle having a left and a right drive shaft, said secondary axle being driven via output elements of the axle differential and by at least two shifting elements arranged coaxial to the axle differential and acting on the left and a right drive shafts of the secondary axle via belt drives.

2. The drive device of claim 1 , wherein the shifting elements are formed by clutches.

3. The drive device of claim 2 , wherein the clutches close in response to rotational speed differences between wheels of the four-wheel drive motor vehicle.

4. The drive device of claim 2 , wherein the belt drives are one-part or multipart belt drives.

5. The drive device of claim 2 , further comprising controllable shifting devices integrated in drive shafts that drive wheels of the secondary axle.

6. The drive device of claim 5 , wherein the shifting devices are configured for deactivation of the belt drives when the clutches are in a disengaged state.

7. The drive device of claim 5 , wherein the controllable shifting devices are constructed as clutches.

8. The drive device of claim 1 , wherein the at least two shifting elements are formed by two clutches that form a dual-clutch having two input elements and two output elements, said two input elements being drivingly connected with two of the output elements of the axle differential, said two output elements of the dual-clutch being connected to the belt drives, said belt drives being arranged directly adjacent each other, said axle differential being configured as a planetary transmission.

9. The drive device of claim 1 , wherein the axle differential of the primary axle is integrated in the drive aggregate and is configured as a planetary transmission, and wherein the shifting elements and input elements of the belt drives are arranged coaxial to drive shafts of the primary axle on a side of the drive aggregate.

10. The drive device of claim 1 , wherein the axle differential is configured as a bevel-gear differential and wherein the shifting elements and the belt drives are positioned on two respective sides of the axle differential.

11. The drive device of claim 10 , wherein the shifting elements are formed by two clutches.

12. The drive device of claim 1 , wherein the axle differential and the shifting elements are arranged in an axle housing of the primary axle, wherein the axle differential is driven via an output shaft of the drive aggregate, and wherein the two belt drives are guided on both sides past the drive aggregate to the secondary axle.

13. The drive device of claim 1 , further comprising a respective step-up gear transmission assigned to the belt drives on an input side of the drive aggregate and on an output side of the drive aggregate, and a respective step-down gear transmission is assigned to the belt drives.

14. The drive device of claim 13 , wherein the gear transmissions are constructed as planetary transmissions arranged coaxial to drive shafts of the primary axle and to the drive shafts of the secondary axle, with ring gears of the planetary transmissions being fixed to a housing of the planetary transmission and with input elements and output elements of the planetary transmission being formed by a planet carrier and a sun gear of the planetary transmission.

15. The drive device of claim 13 , wherein transmission ratios of the step-up gear transmissions and the step-down gear transmissions at the primary axle and the secondary axle are configured so that when the motor vehicle drives straight ahead the drive shafts of a rear axle of the motor vehicle rotate faster than the drive shafts of a front axle of the motor vehicle by a defined degree.

16. The drive device of claim 1 , wherein the at least two shifting elements which output to the belt drives are formed by gear transmission constructed as planetary transmissions on the primary axle, with planet carriers of the planetary transmissions being driven via the output elements of the axle differential, with sun gears of the planetary transmissions outputting to the input elements of the belt drives, said drive device further comprising brakes on a housing of the planetary transmission, said brakes being configured for arresting ring gears of the planetary transmissions.

17. A method for operating a drive device for a four-wheel-drive motor vehicle, comprising:
driving a primary axle with a drive aggregate via an axle differential; and
driving a secondary axle having a left and a right drive shaft, via output elements of the axle differential and by at least two shifting elements arranged coaxial to the axle differential and acting on the left and a right drive shafts of the secondary axle via belt drives.

Assignees

• Audi Ag

Inventors

• Meixner Christian

Classifications

• B60K17/348 Primary

  having differential means for driving one set of wheels, e.g. the front, at one speed and the other set, e.g. the rear, at a different speed (B60K17/346 takes precedence) · CPC title

• F16H7/023

  with belts having a toothed contact surface or regularly spaced bosses or hollows for slipless or nearly slipless meshing with complementary profiled contact surface of a pulley · CPC title

• B60K17/342 Primary

  having a longitudinal, endless element, e.g. belt or chain, for transmitting drive to wheels · CPC title