Abstract
A method for producing a joint outer part by means of flow forming may involve positioning a blank on a contour mandrel such that the blank cannot rotate with respect to the contour mandrel, driving the contour mandrel such that the blank and the contour mandrel rotate about a common axis, and shaping the blank at least partially with the aid of a flow forming roller that acts on the blank to form the joint outer part. Further, shaping the blank at least partially with the aid of the flow forming roller may comprise forming at least one track with a concave region in the joint outer part.
Claims
1.-10. (canceled)
11. A method for producing a joint outer part by way of flow forming, the method comprising: positioning a blank on a contour mandrel such that the blank is prevented from rotating with respect to the contour mandrel; driving the contour mandrel such that the contour mandrel and the blank rotate about a common axis; and shaping the blank at least partially with the aid of a flow forming roller that acts on the blank to form the joint outer part that includes a track with a concave region.
12. The method of claim 11 wherein the track is a cage track.
13. The method of claim 11 wherein shaping the blank at least partially with the aid of the flow forming roller comprises forming the track with the aid of a rolling beam.
14. The method of claim 11 wherein the track is a ball track.
15. The method of claim 14 wherein shaping the blank at least partially with the aid of the flow forming roller comprises forming a cage track in the joint outer part.
16. The method of claim 15 wherein shaping the blank at least partially with the aid of the flow forming roller comprises forming a structure edge between the ball track and the cage track.
17. A joint outer part comprising a track with a concave region, wherein the track is produced by positioning a blank on a contour mandrel such that the blank is prevented from rotating with respect to the contour mandrel, driving the contour mandrel such that the contour mandrel and the blank rotate about a common axis, and shaping the blank at least partially with the aid of a flow forming roller that acts on the blank to form the joint outer part that includes the track with the concave region.
18. The joint outer part of claim 17 wherein the track is a ball track.
19. The joint outer part of claim 18 further comprising a cage track.
20. The joint outer part of claim 17 wherein the track is a cage track.
21. A tool for producing a joint outer part by way of flow forming, the tool comprising: a contour mandrel for receiving a blank in a manner such that the blank is prevented from rotating with respect to the contour mandrel; a drive for driving the contour mandrel such that the blank and the contour mandrel are rotatable substantially about a common axis; and a flow forming roller that acts on the blank to form a track with a concave region in the joint outer part.
22. The tool of claim 21 further comprising a rolling beam for forming the track.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 shows a flowchart in accordance with one exemplary method of the present invention.
[0023] FIG. 2 shows a diagrammatic perspective view in accordance with a further subject matter of the present invention.
[0024] FIG. 3 shows a diagrammatic perspective view in accordance with a further subject matter of the present invention.
[0025] FIG. 4 shows a diagrammatic perspective view in accordance with a further subject matter of the present invention.
[0026] FIG. 5 shows a diagrammatic perspective view and sectional views of one exemplary embodiment of the present invention according to FIG. 3 and FIG. 4.
EMBODIMENTS OF THE INVENTION
[0027] In the various figures, identical parts are always provided with the same designations and will therefore also as a rule be named or mentioned in each case only once.
[0028] FIG. 1 shows a flowchart in accordance with one exemplary method for producing joint outer parts 1 which are shown in FIG. 2, FIG. 3, FIG. 4 and FIG. 5 by means of flow forming. In the case of the method which is shown here, a blank is arranged on a contour mandrel such that it cannot rotate with respect to the contour mandrel in a first method step 101. The contour mandrel comprises, for example, a plurality of contour mandrel parts, with the result that undercuts can also be realized in the joint outer part 1. In particular, the contour mandrel is formed in such a way that the outer face of the contour mandrel corresponds substantially to the inner contour of the joint outer part 1. In a second method step 102, the contour mandrel is driven in such a way that the blank and the contour mandrel rotate about a common axis. In a third method step 103, the blank is shaped at least partially with the aid of a flow forming roller which acts on the blank substantially perpendicularly with respect to the common axis in order to form the joint outer part 1. It is also provided, for example, that the flow forming roller acts on the blank substantially parallel to the common axis. It is also conceivable that the blank and the contour mandrel are mounted such that they can be rotated merely about a common axis, and the drive takes place with the aid of the flow forming roller or the flow forming rollers. In the third method step 103, in particular, at least one track 3 is formed with a concave region 5 in the joint outer part 1. In the third method step 103, for example, at least one ball track 9 which is shown in FIG. 3, FIG. 4 and FIG. 5 is formed with the concave region 5 in the joint outer part 1.
[0029] In the third method step 103, in addition or as an alternative, for example, a cage track 11 which is shown in FIG. 3, FIG. 4 and FIG. 5 is formed with the concave region 5 in the joint outer part 1. In the third method step 103, for example, the track 3 is formed with the aid of a rolling beam 13 which is shown in FIG. 5. Furthermore, in the third method step 103, for example, a structure edge 15 which is shown in FIG. 3, FIG. 4 and FIG. 5 is formed between the ball track 9 and the cage track 11.
[0030] FIG. 2 shows a joint with a joint outer part 1 and with a joint inner part 2. A joint of this type is also called a constant velocity joint and transmits the angular velocity and the torque uniformly from a shaft of the joint outer part 1 to a shaft of the joint inner part 2 or from the shaft of the joint inner part 2 to the shaft of the joint outer part 1 with the aid of balls 4. During operation of the constant velocity joint, said balls 4 move in each case along at least one track 3 or one ball track 9 in the joint outer part 1 and along at least one track 3 or ball track 9 in the joint inner part 2. A superimposition of sliding friction and rolling friction occurs between the balls 4 and the joint outer part 1 and between the balls 4 and the joint inner part 2 as a result of the relative movement of the joint outer part 1 with respect to the joint inner part 2. Said superimposition is also called rolling friction. Satisfactory lubrication of constant velocity joints is necessary in order to minimize said rolling friction. The service life of joints is increased significantly by way of optimized lubrication. FIG. 2 diagrammatically shows a cage 6 which additionally defines the relative spacings of the balls 4 from one another. FIG. 2 does not show a cage track 11 for an improved view of the method of operation of the constant velocity joint.
[0031] The joint outer part 1 (shown partially in FIG. 3 and FIG. 4) of a constant velocity joint is preferably produced by way of the method according to the invention, other production methods also being provided for producing the joint outer part 1. The joint outer part 1 which is shown in FIG. 3 and FIG. 4 comprises a cage track 11 which by way of six ball tracks 9 with in each case one concave region 5. Here, each of the six ball tracks 9 comprises a concave region 5, and the cage track 11 comprises a concave region 5. In FIG. 3, the concave regions 5 and 5 of the ball tracks and the cage track are shown in a hatched manner. In FIG. 4, in contrast, the regions which are elevated with respect to the concave regions or the non-concave regions of the ball tracks and the cage track are shown in a hatched manner. In the exemplary embodiment which is shown here, the non-concave regions of the ball tracks 9 are the loadbearing regions or the regions which guide the balls 4 and transmit the angular velocity and the torque uniformly. The lubrication between the balls 4 and the non-concave regions of the ball tracks is improved by way of the provision of grease in the concave regions 5. Furthermore, additional lubricant reservoirs are provided in the concave regions 5 of the cage track. Said lubricant reservoirs provide additional lubricant for the lubrication of the constant velocity joint. Non-concave regions of the cage track 11 in each case directly adjoin the loadbearing regions of the ball tracks 9. Here, respective adjacent loadbearing regions of the ball tracks 9 form a structure edge 15 with the non-concave regions of the cage track 11. The exemplary embodiment which is shown here therefore comprises twelve structure edges 15.
[0032] It is advantageously also provided that the ball tracks 9 in the joint inner part 2 which is shown in FIG. 2 and, as an alternative or in addition, those regions of the joint inner part 2 which lie between the ball tracks 9 in each case comprise one or more concave regions 5. As a result, lubricant reservoirs can also be provided on the joint inner part 2, and the service life of constant velocity joints can therefore be increased.
[0033] The exemplary embodiment which is shown in FIG. 5 corresponds substantially to the exemplary embodiment which is shown in FIG. 3 and FIG. 4. FIG. 5 additionally shows a rolling beam 13 of an exemplary tool for producing the joint outer part 1 according to the invention. Furthermore, FIG. 5 shows sectional illustrations of the joint outer part 1 along different planes perpendicularly with respect to the rotational axis of the joint outer part. In addition to the contour mandrel or the contour mandrel which comprises a plurality of contour mandrel parts, the tool comprises, for example, a drive for driving the contour mandrel in such a way that the blank and the contour mandrel can be rotated substantially about a common axis. Furthermore, the tool comprises the flow forming roller which acts on the blank substantially perpendicularly with respect to the common axis, for example, in order to form the at least one track 3 with a concave region 5 in the joint outer part 1.
LIST OF DESIGNATIONS
[0034] 1 Joint outer part
[0035] 2 Joint inner part
[0036] 3 Track
[0037] 4 Ball
[0038] 5, 5, 5 Concave region
[0039] 6 Cage
[0040] 9 Ball track
[0041] 11 Cage track
[0042] 13 Rolling beam
[0043] 15 Structure edge
[0044] 101 First method step
[0045] 102 Second method step
[0046] 103 Third method step
