Displacement unit and universal shaft comprising a displacement unit

1. A displacement unit comprising:

a tubular outer part on an inner surface of which outer paths are provided at least in sections,

an inner part that is displaceable in the tubular outer part in axial direction, on whose exterior surface inner paths are provided at least in sections, and

a plurality of balls that are guided in a cage, the balls respectively located in outer paths and inner paths that are associated with each other in pairs for transmitting torque,

whereby the tubular outer part and/or the inner part is provided with cage guide paths between at least some of the exterior paths or inner paths for axial guiding of the cage,

wherein a quantity of the cage guide paths is smaller than the quantity of pairs of paths that is formed by the outer paths and the inner paths

wherein the cage is made of plastic and comprises a plurality of integral guide path protrusions, the integral guide path protrusions engaging the cage guide paths, and

wherein the displacement unit comprises a roller balance whereby in the pairs of paths that are formed by the outer paths and the inner paths several balls are provided in an axial direction.

2. Displacement unit according to claim 1 , wherein between two neighboring cage guide paths, at least two outer paths or at least two inner paths are located.

3. Displacement unit according to claim 1 wherein the cage guide paths are designed in the outer part.

4. Displacement unit according to claim 1 wherein the cage guide paths are designed in the inner part.

5. Displacement unit according to claim 1 , wherein the cage guide paths have a contour differing in cross section from the contours of the outer paths and inner paths.

6. Displacement unit according to claim 1 , wherein the cage guide paths have angular or rounded contours in cross section.

7. Universal shaft comprising at least one roller balance or a displacement joint according to claim 1 .

8. Universal shaft according to claim 1 with at least two shaft sections that respectively have a flute tube,

which are connected with one another by a middle joint and which have, on their ends facing away from the middle joint a joint on a side of a gear and on a differential side, respectively,

whereby the joint on the side of the gear, the joint on the differential side and the middle joint are designed as fixed joints.

9. Universal shaft according to claim 1 with at least two shaft sections that respectively have a flute tube,

which are connected with one another by a middle joint and which have, on their ends facing away from the middle joint a joint on a side of a gear or on a differential side,

whereby the joint on the side of the gear, the joint on the differential side and the middle joint are designed as fixed joints

wherein

two roller balances are provided that are associated with the middle joint and are mounted adjacent the middle joint.

10. Universal shaft according to claim 9 ,

wherein the inner part of the second roller balance is connected with an inner race of the middle joint and the inner part of the first roller balance connected with an outer race of the middle joint.

11. Universal shaft according to claim 9 ,

wherein the inner part of a roller balance, particularly of the first roller balance is mounted in an intermediate bearing.