Connection Device for a Drive Train

Abstract

The invention provides a connection device for a joint shaft in a motor vehicle. The connection device includes an axis of rotation, a first connection area for connecting the connection device to a drive train element, a predetermined breaking region, and a tube region which connects directly to the predetermined breaking region. The connection device has an axial extension in the direction of the axis of rotation, and a radial extension orthogonal to the axis of rotation and is designed, at least substantially, as a tubular hollow body. The predetermined breaking region is arranged between the first connection region and the tube region in the axial direction. A connection area is arranged in the axial direction between the first connection region and the predetermined breaking region.

Claims

1. A connection device for a shaft in a motor vehicle, comprising: an axis of rotation; a first connection region for connecting the connection device to a drive train element; a predetermined breaking region; and a tube region which directly adjoins the predetermined breaking region, wherein the connection device has an axial extent in an axial direction of the axis of rotation and a radial extent orthogonal thereto and is formed at least in part as a tubular hollow body, the predetermined breaking region is arranged between the first connection region and the tube region in the axial direction, a connecting region is arranged in the axial direction between the first connection region and the predetermined breaking region, the greatest outer radial extent of the first connection region is smaller than the greatest outer radial extent of the connecting region, and the greatest outer radial extent of the connecting region is smaller than the smallest inner radial extent of the tube region.

2. The connection device according to claim 1, wherein the greatest outer radial extent of the first connection region is smaller than the smallest inner radial extent of the connecting region.

3. The connection device according to claim 1, wherein the predetermined breaking region is formed as a radially outwardly curved connection between the tube region and the connecting region.

4. The connection device according to claim 2, wherein the predetermined breaking region is formed as a radially outwardly curved connection between the tube region and the connecting region.

5. The connection device according to claim 1, further comprising: a second connection region which adjoins the tube region in the axial direction, wherein the second connection region, relative to the first connection region, is arranged on an opposite side of the predetermined breaking region and the second connection region is provided for connecting to another drive train element.

6. The connection device according to claim 4, further comprising: a second connection region which adjoins the tube region in the axial direction, wherein the second connection region, relative to the first connection region, is arranged on an opposite side of the predetermined breaking region and the second connection region is provided for connecting to another drive train element.

7. The connection device according to claim 1, wherein the connection device has, at least in part, a wall thickness which is greater than 0.5 mm and smaller than 5 mm.

8. The connection device according to claim 7, wherein the wall thickness is greater than 0.75 mm and smaller than 4 mm.

9. The connection device according to claim 8, wherein the wall thickness is greater than 1.25 mm and smaller than 3 mm.

10. The connection device according to claim 9, wherein the wall thickness is greater than 1.75 mm and smaller than 2.25 mm.

11. The connection device according to claim 6, wherein the connection device has, at least in part, a wall thickness which is greater than 1.75 mm and smaller than 2.25 mm.

12. The connection device according to claim 1, wherein the connection device has a steel material as a component or is composed of a steel material.

13. The connection device according to claim 1, further comprising: at least one of the first connection region, the connecting region, and the tube region has a hollow cylindrical body.

14. The connection device according to claim 13, wherein all of the first connection region, the connecting region, and the tube region have a hollow cylindrical body.

15. The connection device according to claim 11, wherein all of the first connection region, the connecting region, and the tube region have a hollow cylindrical body.

16. The connection device according to claim 5, wherein the second connection region has a hollow cylindrical body.

17. The connection device according to claim 1, wherein a first tapering region is arranged between the first connection region and the connecting region, and a rigidity of the predetermined breaking region in the axial direction is lower than a rigidity of the first tapering region.

18. The connection device according to claim 1, wherein a first tapering region is arranged between the first connection region and the connecting region, and a strength of the predetermined breaking region in the axial direction is lower than a strength of the first tapering region.

19. The connection device according to claim 1, wherein the shaft in the motor vehicle is a cardan shaft.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0034] FIG. 1 is a longitudinal sectional view of a connection device.

DETAILED DESCRIPTION OF THE DRAWINGS

[0035] FIG. 1 shows a longitudinal sectional view of a connection device 1. Here, the connection device 1 has a first connection region 1A, a connecting region 2A, a predetermined breaking region 3, a tube region 4 and a second connection region 1B. The connection device 1 is rotatable about the axis of rotation 7 so that speed and torque may be transferred thereby upon a rotation about the axis of rotation 7. The connection device 1 further has a circular cross-section in a sectional plane (not illustrated) which is arranged orthogonally to the axis of rotation 7. The connection regions 1A and 1B are designed for transferring torque to the drive train elements (not illustrated) and formed as hub portions. The design of the predetermined breaking region 3 is based on the predetermined axial forces, i.e., forces in the direction of the axis of rotation 7 under which the connection device 1 should break off/fail as intended. The connection device 1 has a radial extent in the orthogonal direction 9 to the axis of rotation 7 and axial extents in the longitudinal direction 8 of the axis of rotation 7. The connection device 1 has a substantially constant mean wall thickness t.

[0036] Wall thicknesses which deviate slightly from the mean wall thickness t can be produced in particular in the region of bends. To enable an intentional telescoping of the regions 1A, 2, 4 into one another, a particular diameter gradation of these regions is required. It is important here that the greatest outer radial extent 5 of the first connection region 1A is smaller than the smallest radial extent 10 of the inner surface of the tube region 4.

[0037] Test results have shown that a radial extent 6 of the connecting region 2 which is between the radial extent 5 and the radial extent 10 enables a particularly reliable function of the connection device 1 to be achieved, in particular during the intentional failure of the predetermined breaking region 3. It is further advantageous if even the smallest inner radial extent 2A of the connecting region 2 is greater than the greatest outer radial extent 5 of the first connection region 1A.

[0038] The first tapering region 11 is arranged between the first connection region 1A and the connecting region 2. The rigidity of the tapering region 11 in the direction of the axis of rotation 7 is greater than the rigidity of the predetermined breaking region 3, which is formed as a bead between the connecting region 2 and the tube region 4, in the same direction. The rigidity of the predetermined breaking region 3 in this direction is further lower than the rigidity of the second tapering region 12 between the tube region 4 and the second connection region 1B. The strengths of the regions 11, 12, 4 have the same behaviors as their rigidities so that, under an axial load in the direction of the axis of rotation 7, the predetermined breaking region 3 fails as intended before other regions of the connection device 1, in particular the tapering regions 11, 12 fail. The failure here refers to the breaking or separation of the connection device 1.

[0039] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.