Live twist beam axle assembly

1. A drive axle and suspension assembly for an all-wheel-drive vehicle having an engine, front wheels and rear wheels, the axle and suspension assembly comprising:

a rear axle housing;

a first twist element fixed to the axle housing;

a second twist element fixed to the axle housing;

a first axle shaft rotatably positioned adjacent the first twist element and adapted to receive drive torque from the engine;

a second axle shaft rotatably positioned adjacent the second twist element and adapted to receive drive torque from the engine; and

first and second transfer shafts each drivingly coupled to the respective first and second axle shafts, each transfer shaft being adapted to transfer torque to one of the rear wheels, wherein the first and second twist elements form part of the vehicle suspension, each twist element being operable to store and release energy as a torsion spring.

2. The assembly of claim 1 wherein the rear axle housing rotatably supports a differential gear assembly.

3. The assembly of claim 2 wherein a first gear of the differential gear assembly is fixed for rotation with the first axle shaft and a second gear of the differential gear assembly is fixed for rotation with the second axle shaft.

4. The assembly of claim 3 further comprising:

first and second arms rotatably supporting the respective first and second transfer shafts, the first and second arms each having a first portion fixed to a corresponding first and second twist element;

first and second support members fixed to a second portion of each of the first and second arms; and

first and second output shafts rotatably supported by the respective first and second support members, the first and second output shafts transferring drive torque from the respective first and second transfer shafts to the rear wheels.

5. The assembly of claim 4 further including first and second springs as well as first and second shock absorbers coupled to the respective first and second arms.

6. The assembly of claim 1 wherein the first and second twist elements each include a plurality of apertures extending therethrough.

7. The assembly of claim 1 wherein the first twist element includes an “L”-shaped cross-section.

8. The assembly of claim 7 wherein the first axle shaft is at least partially positioned within a pocket defined by the first twist element.

9. The assembly of claim 1 further including first and second output shafts, each output shaft drivingly coupled to respective first and second transfer shafts, each output shaft being fixed for rotation with a wheel hub.

10. The assembly of claim 9 wherein each of the first and second axle shafts, the first and second transfer shafts and the first and second output shafts have gears fixed for rotation therewith.

11. The assembly of claim 9 wherein the first axle shaft is fixed for rotation with a first gear in meshing engagement with a second gear fixed for rotation with the first transfer shaft, the assembly further including a third gear fixed for rotation with the first transfer shaft and in meshed engagement with a fourth gear fixed for rotation with the first output shaft.

12. An axle and suspension assembly for a vehicle having a chassis, a power source and wheels, comprising:

first and second torsionally compliant twist elements defining a first lateral axis;

arm portions fixed to each of the first and second twist elements and adapted to rotatably support two of the wheels of the vehicle along a second axis extending substantially parallel to the first axis; and

a driveline assembly adapted to receive torque from the power source and drive the wheels, the driveline assembly including a plurality of power transmission components rotatably supported by the arm portions.

13. The assembly of claim 12 wherein the arm portions are pivotable relative to the vehicle chassis about a third axis offset from the first and second axes.

14. The assembly of claim 13 wherein the driveline includes a differential gear assembly.

15. The assembly of claim 14 wherein the differential gear assembly includes a side gear fixed for rotation with one of the power transmission components.

16. The assembly of claim 12 wherein each of the twist elements includes first and second substantially planar leg portions interconnected to one another at one edge.

17. The assembly of claim 16 wherein a portion of the driveline assembly is positioned within a pocket defined by the leg portions.

18. The assembly of claim 12 wherein two of the power transmission components are shafts drivingly interconnected by a flexible member.

19. The assembly of claim 12 wherein two of the power transmission components are shafts drivingly interconnected with gears.

20. The assembly of claim 19 wherein two of the power transmission components are shafts drivingly interconnected with bevel gears.