CONSTANT VELOCITY JOINT COMPRISING INTEGRAL INTERNAL JOINT PART AND METHOD FOR PRODUCING SUCH A CONSTANT VELOCITY JOINT

Abstract

A constant velocity joint includes an external joint part including internal ball tracks, an internal joint part including external ball tracks assigned to the internal ball tracks, and a ball cage holding balls. The external joint part is connectable to a connecting part and sealed by a closure cap on the side facing this connecting part. The internal joint part is an integral internal joint part connected permanently to a shaft piece, sealed on this side towards the external joint part by a flexible sealing element, hardened, and has a protruding welding attachment for an adapter on its free end. The welding attachment outer diameter is larger than the smallest integral internal joint part outer diameter. In a method, the sealing element is mounted over the integral internal joint part free end and connected to the external joint part, the adapter subsequently welded near the welding attachment.

Claims

1. A constant velocity joint, comprising an external joint part (1) comprising internal ball tracks, an internal joint part (2) comprising external ball tracks assigned to the internal ball tracks, and of balls (4) held in a ball cage (3), wherein the external joint part (1) can be connected to a connecting part and is sealed by means of a closure cap (7) on the side facing this connecting part, and the internal joint part (2) is embodied as an integral internal joint part (6), which is connected to a shaft piece in a destruction-free, permanent manner and is sealed on this side towards the external joint part (1) by means of a flexible sealing element (10), wherein, on its free end, which protrudes from the sealing element (10), the integral internal joint part (6) is provided with a welding attachment (15) for accommodating an adapter (16), wherein the outer diameter of this welding attachment (15) is larger than the smallest outer diameter of the integral internal joint part (6) and wherein the integral internal joint part (6) is hardened.

2. The constant velocity joint according to claim 1, wherein the outer diameter of the integral internal joint part (6) is smallest in the area of the accommodation of the sealing element (10).

3. The constant velocity joint according to claim 1, wherein the adapter is a tube adapter (16).

4. The constant velocity joint according to claim 2, wherein the adapter is a tube adapter (16).

5. A method for producing a constant velocity joint, comprising an external joint part (1) comprising internal ball tracks, an internal joint part (2) comprising external ball tracks assigned to the internal ball tracks, and of balls (4) held in a ball cage (3), wherein the external joint part (2) can be connected to a connecting part and is sealed by means of a closure cap (7) on the side facing this connecting part, and the internal joint part (2) is embodied as integral internal joint part (6), which is connected to a shaft piece (5) in a destruction-free, permanent manner and is sealed on this side towards the external joint part (1) by means of a flexible sealing element, wherein, on its free end, which protrudes from the sealing element (10), the integral internal joint part (6), which is connected to the shaft piece (5), is provided with a welding attachment (15) for accommodating an adapter (6), wherein the outer diameter of this welding attachment (15) is larger than the smallest outer diameter of the integral internal joint part (6), wherein the integral internal joint part (2) is hardened, wherein the sealing element (10) is mounted over the end of the integral internal joint part (6), which has the smaller outer diameter, and is connected to the external joint part (1) and wherein the adapter (16) is subsequently welded to the integral internal joint part (6) in the area of the welding attachment (15).

6. The method according to claim 5, wherein the integral internal joint part (6) is surface layer hardened.

7. The method according to claim 5, wherein the adapter (16) is welded to the prefabricated constant velocity joint only after being connected to a connecting part.

8. The method according to claim 6, wherein the adapter (16) is welded to the prefabricated constant velocity joint only after being connected to a connecting part.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Other objects and features of the invention will become apparent from the following detailed description considered in connection with the accompanying drawings which show a preferred exemplary embodiment of the subject matter according to the invention and will be explained in more detail below. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.

[0017] In the drawings,

[0018] FIG. 1a shows a constant velocity joint according to the invention,

[0019] FIG. 1b shows a tube adapter, and

[0020] FIG. 2 shows the constant velocity joint welded to the tube adapter.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0021] The constant velocity joint according to the invention illustrated in FIG. 1a consists of an external joint part 1, which can be flanged, and of an internal joint part 2, which is connected in a rotationally fixed manner to the external joint part 1 via balls 4 held in a cage 3. The balls 4 are thereby accommodated by internal ball tracks of the external joint part 1 as well as external ball tracks of the internal joint part 2. The internal joint part 2, together with a shaft piece 5, which is connected thereto in one piece, forms an integral internal joint part 6. On the side facing away from the internal joint part 2, the constant velocity joint is sealed by means of a closure cap 7, which rests against the external joint part 1 via a flat seal 8. On the side of the shaft piece 5 of the integral internal joint part 6, the latter is sealed by means of a sealing cap 9 and a bellows 10. The sealing cap 9 also rests against the external joint part 1 via a flat seal 8 and is screwed to the latter by means of cylinder screws 11 and washers 12. With its free front side, which is formed into a flanged edge for this purpose, the sealing cap 9 accommodates the bellows 10. With its other side, the bellows 10 is fastened by means of a tension clip 14 to the integral internal joint part 6 in a bellows seat 13, the diameter of which is reduced as compared to the outer diameter of the integral internal joint part 6. On its outer free end, the integral internal joint part 6 is provided with a diameter, which is slightly enlarged as compared to its outer diameter and which forms a welding attachment 15.

[0022] The integral internal joint part 6 can be produced from a tempering steel or a case-hardened steel. Depending on the used material, a suitable hardening method, such as induction or case-hardening can be chosen, in order to harden the edge layer of the integral internal joint part 6 across the entire axial length. On the one hand, the wear resistance in the raceways of the balls 4 is attained through this, on the other hand, the stability for transferring the torque, in particular to the smallest diameter in the area of the bellows seat 13, is ensured as well.

[0023] The constant velocity joint can be assembled for example in a joint shaft. However, it can be assembled so as to be decoupled therefrom, in that the integral internal joint part 6, the ball cage 3 and the external joint part 1 are first equipped with the balls 4. The flat seals 8, the sealing cap 9, which is provided with the bellows 10, and the closure cap are then attached from both sides, the constant velocity joint is filled with grease and the closure cap 7 and the sealing cap 9 are subsequently pressed onto the outer diameter of the external joint part 1.

[0024] The constant velocity joint, which is preassembled in this way, is subsequently welded to the integral internal joint part 6 by means of a tube adapter 16, which is illustrated in FIG. 1b and which, on its front side, which faces the integral internal joint part 6, has an opening 17, which corresponds to the diameter of the welding insert 15. In the example at hand, the tube adapter 16 is provided with a tube attachment 18 on its front side, which faces away from the integral internal joint part 6. For example friction welding, magnet arc or laser welding can be used as welding methods. In the example at hand, the joint is designed for the sliding friction welding, which is known for example from DE 10 2008 064 267 A1. As described above, the joint diameter of the welding attachment 15 is thereby chosen to be larger than the smallest diameter in the area of the bellows seat 13, in order to constructively counteract the softening of the edge layer by means of the welding process. However, the maximum expansion of the bellows 10, which must be capable of being slipped over this end of the integral internal joint part 6, as described in response to the assembly of the constant velocity joint, provides an upper limit for the diameter of the welding attachment 15. The axial distance between the bellows seat 13 and the welding attachment 15 must thereby be sufficiently large in order to protect the bellows 10 against the influence of the welding heat.

[0025] FIG. 2 illustrates the constant velocity joint, which is welded to the tube adapter 16. A welding bead 19, which is created when friction welding is used, can subsequently be removed by machining, if needed. For the further production of the joint shaft, this assembly can be joined to further partial assemblies of the joint shaft, e.g. via the tube attachment 18.

[0026] All of the features illustrated herein can be significant for the invention, both alone and in any combination with one another.

[0027] Although only a few embodiments of the present invention have been shown and described, it is to be understood that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.

LIST OF REFERENCE NUMERALS

[0028] 1 external joint part

[0029] 2 internal joint part

[0030] 3 ball cage

[0031] 4 balls

[0032] 5 shaft piece

[0033] 6 integral internal joint part

[0034] 7 closure cap

[0035] 8 flat seal

[0036] 9 sealing cap

[0037] 10 bellows

[0038] 11 cylinder screw

[0039] 12 washer

[0040] 13 bellows seat

[0041] 14 tension clip

[0042] 15 welding attachment

[0043] 16 tube adapter

[0044] 17 opening

[0045] 18 tube attachment

[0046] 19 welding bead