PIVOT BEARING OF A HYDRAULIC CLEARANCE COMPENSATION ELEMENT

Abstract

A pivot bearing (1) for a hydraulic clearance compensation element (2), especially of a valve train of an internal combustion engine, is provided in which the pivot bearing (1) has a first part (3) projecting in an axial direction (a) with a surface (4) that is convex at least in some sections and also a second part (5) with a surface (6) that is concave at least in some sections for at least partially holding the first part (3). To optimize the production of such a pivot bearing and to minimize the associated costs, the invention provides that the first part (3) is constructed at least partially as a ball, wherein the second part (5) surrounds the ball (3) with undercut in the axial direction (a).

Claims

1. A pivot bearing of a hydraulic clearance compensation element, the pivot bearing comprising a first part projecting in an axial direction (a) with a surface that is convex at least in some sections and a second part with a surface that is concave at least in some sections for at least partially holding the first part, the first part is constructed at least partially as a ball, and the second part surrounds the ball with an undercut in the axial direction (a).

2. The pivot bearing according to claim 1, wherein the first part and the second part are free from plastic deformation after production.

3. The pivot bearing according to claim 1, wherein the first part and the second part each are constructed as one-piece parts and the first part is a ball that is connected together with the second part with a snap-fit connection.

4. The pivot bearing according to claim 3, wherein the second part is constructed in an area thereof surrounding the ball with an undercut as an interruption-free circumferential edge.

5. The pivot bearing according to claim 4, wherein the circumferential edge has a radial thickness (d) that is between 3% and 10% of a diameter (D) of the ball.

6. The pivot bearing according to claim 1, wherein an opening of the second part provided for holding the ball has, viewed in the axial direction (a), a non-round contour.

7. The pivot bearing according to claim 6, wherein the opening of the second part provided for holding the ball has, viewed in the axial direction (a), an elliptical contour.

8. The pivot bearing according to claim 6, wherein the opening of the second part provided for holding the ball has, viewed in the axial direction (a), a contour that has a maximum distance (b) from the axis (a) at three or more positions considered over a circumference of the opening.

9. The pivot bearing according to claim 8, wherein a circumferential edge of the second part is constructed as a curve of constant width.

10. The pivot bearing according to claim 9, wherein a length of a smallest internal circumference of the circumferential edge of the second part is greater than or equal to a length of a circumference of the ball.

11. The pivot bearing according to claim 1, wherein the pivot bearing forms a part of a valve train of an internal combustion engine.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Embodiments of the invention are shown in the figures. Shown are:

[0031] FIG. 1 is a view in a radial section, a clearance compensation element of a valve train of an internal combustion engine, wherein a second part (ball socket) of a pivot bearing is shown in a mounted position and in a not yet mounted position,

[0032] FIG. 2A is a perspective view of the second part of a pivot bearing according to a first embodiment of the invention,

[0033] FIG. 2B is a radial section of the portion of the pivot bearing according to FIG. 2A,

[0034] FIG. 2C is a top view of the section of the pivot bearing according to FIG. 2A,

[0035] FIG. 3A is a perspective view of the second part of a pivot bearing according to a second embodiment of the invention,

[0036] FIG. 3B is a radial section of the portion of the pivot bearing according to FIG. 3A, and

[0037] FIG. 3C is a top view of the portion of the pivot bearing according to FIG. 3A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] In FIG. 1, a clearance compensation element 2 of a valve train of an internal combustion engine is shown. Concerning the general construction of such a clearance compensation element and its use, reference is explicitly made to the previously known solutions mentioned above according to DE 199 50 585 A1, DE 37 25 245 A1 and DE 195 05 406 A1, both of which are incorporated herein by reference as if fully set forth. For actuating a valve shaft 12, the clearance compensation element 2 has, in its lower section, a pivot bearing 1 that includes a first part 3 in the form of a ball and a second part 5 in the form of a ball socket. The ball 3 has a convex surface 4 that is in sliding contact with the concave surface 6 of the ball socket 5 in the assembled state of the arrangement.

[0039] It is essential that the second part 5 surrounds the ball 3 with undercut in the axial direction a. Here, refer to an area 7 of the second part 5 that surrounds the ball 3 with undercut—viewed in the axial direction a.

[0040] Both the ball 3 and also the ball socket 5 are left free from plastic deformation after their production (i.e., after the cutting or non-cutting processing, heat treatment, and fine processing).

[0041] This applies especially also to the assembly process of the ball 3 and ball socket 5, in which both parts are moved toward each other and pressed together relative to each other in the axial direction a; this is indicated in FIG. 1 by the arrow.

[0042] So that the stated assembly process can take place without plastic deformation, a circumferential edge 8 that has a relatively thin construction is arranged on the ball socket 5. Recorded in FIG. 1 are the radial thickness d of the circumferential edge 8 and the diameter D of the ball 3. The radial thickness d of the circumferential edge 8 is here on the order of magnitude of 5% of the diameter D of the ball 3.

[0043] Accordingly, during the stated axial relative motion, the ball socket snaps onto the ball 3, so that a fixed connection between the two components 3 and 5 is produced.

[0044] To be able to perform the mentioned snapping process with especially minimal and possibly damaging deformation, preferred special measures are taken that are illustrated in FIGS. 2 and 3.

[0045] Here, in two different embodiments, the second part 5, that is, the ball socket, of the pivot bearing 1 is shown. For holding the ball 3, the ball socket 5 has an opening 9 in which the ball enters for assembling the two parts.

[0046] As given from the respective FIGS. 2C and 3C, the opening 9 does not have a round construction, but instead a non-round shape.

[0047] In the solution according to FIG. 2C, an elliptical shape is provided; from FIG. 3C it can be seen that the opening 9 has a contour with three areas especially far from the axis a. Recorded in FIG. 3c are three positions 10 in which the circumferential edge 8 has, with its radial inner surface, a maximum distance b from the axis a (in the elliptical solution according to FIG. 2C, these are, accordingly, two such positions 10).

[0048] If the length 11 (see FIGS. 2B and 3B) of the smallest inner circumference of the edge 8 is considered, it follows that this length is at least as large as the maximum ball circumference. Accordingly, in this case it is possible, in an especially simple way, to realize the snapping process of the ball socket 5 onto the ball 3, because to do this, only the non-round contour has to be temporarily deformed into a round contour, which can take place without plastic effects and thus is especially gentle on the materials.

[0049] The circumferential edge 8 is, in the case of the construction according to FIG. 3, preferably constructed as a curve of constant width, i.e., every diametrically opposed points of the contour have an equal distance from each other.

[0050] With the proposed construction, it is possible to realize the pivot bearing with very few parts that can be produced, in turn, relatively simply and economically.

LIST OF REFERENCE SYMBOLS

[0051] 1 Pivot bearing

[0052] 2 Clearance compensation element

[0053] 3 First part (ball)

[0054] 4 Convex surface

[0055] 5 Second part (ball socket)

[0056] 6 Concave surface

[0057] 7 Area of second part with undercut

[0058] 8 Circumferential edge

[0059] 9 Opening of the second part

[0060] 10 Position with maximum distance

[0061] 11 Length of smallest internal circumference

[0062] 12 Valve shaft

[0063] a Axial direction

[0064] d Radial thickness

[0065] D Diameter of the ball

[0066] b Maximum distance