PIVOT CRADLE BEARING SYSTEM AND METHOD FOR PRODUCING A SYNCHRONISATION DEVICE OF A PIVOT CRADLE BEARING SYSTEM

Abstract

A pivot cradle bearing system includes a curved cage segment in which rolling elements are guided, which are arranged between two bearing parts which can be pivoted relative to each other. A synchronization device, which is designed for the synchronization of the relative movement of the bearing parts with the displacement of the cage segment, comprises a pivot arm, which is mounted in the cage segment. A ball-and-socket joint, by means of which a snap-action connection is formed, is provided to support the pivot arm in the cage segment.

Claims

1. A pivot cradle bearing system comprising: a curved cage segment, in which rolling elements are guided, which are arranged between two bearing parts which can be pivoted relative to one another, wherein a synchronization device, which is designed for the synchronization of a relative movement of the bearing parts with the displacement of the cage segment, comprises a pivot arm, which is mounted in the cage segment, wherein a ball-and-socket joint, by means of which a snap-action connection is formed, is provided to support the pivot arm in the cage segment.

2. The pivot cradle bearing system according to claim 1, wherein an outer sliding bearing piece of the ball-and-socket joint is formed directly by the cage segment.

3. The pivot cradle bearing system according to claim 2, wherein a spring arrangement is formed by the outer sliding bearing piece.

4. The pivot cradle bearing system according to claim 3, wherein the spring arrangement comprises a plurality of spring tongues arranged in an annular manner, each of which is separated from one another by a groove and is formed integrally with a bearing plate, which is formed by the cage segment and in which the ball-and-socket joint is disposed.

5. The pivot cradle bearing system according to claim 4, wherein the spring tongues are surrounded by a single annular groove and do not project beyond the bearing plate.

6. The pivot cradle bearing system according to claim 4, wherein the spring tongues are designed as elevations projecting beyond the bearing plate.

7. The pivot cradle bearing system according to claim 5, wherein the spring tongues are directed radially outwards with respect to a pivot axis of the pivot cradle bearing system.

8. The pivot cradle bearing system according to claim 1, wherein the cage segment is made of plastic and the pivot arm, including an inner sliding bearing piece of the ball-and-socket joint is made of metal.

9. A method for producing a synchronization device of a pivot cradle bearing system, comprising the following steps: providing a cage segment provided for guiding rolling elements, which has a bearing plate through which an outer sliding bearing piece is formed, providing a pivot arm which has a spherical thickened portion spaced apart from ends thereof as an inner sliding bearing piece, wherein a diameter of the inner sliding bearing piece is greater than a minimum inner diameter of the outer sliding bearing piece, inserting the pivot arm into the cage segment, wherein the outer sliding bearing piece is elastically expanded and the inner sliding bearing piece snaps into the outer sliding bearing piece.

10. The method according to claim 9, further comprising snapping the pivot arm into a ball-and-socket joint from an outside, relative to a pivot axis of the pivot cradle bearing system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Below, two exemplary embodiments of the disclosure are explained in more detail by means of a drawing. In the figures:

[0028] FIG. 1 shows components of a first exemplary embodiment of a pivot cradle bearing system in an exploded view,

[0029] FIG. 2 shows a synchronization device of the pivot cradle bearing system according to FIG. 1 in a sectional view,

[0030] FIG. 3 shows a detail of the arrangement according to FIG. 2,

[0031] FIG. 4 shows a cage segment of a second exemplary embodiment of a pivot cradle bearing system,

[0032] FIG. 5 shows a detail of the pivot cradle bearing system comprising the cage segment according to FIG. 4.

DETAILED DESCRIPTION

[0033] Unless otherwise stated, the following explanations relate to both exemplary embodiments. Parts that correspond to each other or have basically the same effect are marked with the same reference symbols in all figures.

[0034] A pivot cradle bearing system 1, only part of which is shown, comprises a curved cage segment 2 made of plastic, in which rolling bodies not shown, namely cylindrical rollers, are guided in cage pockets 3. In the fully assembled state of the pivot cradle bearing system 1, the rolling bodies contact a pivot cradle and a housing as bearing parts that can be pivoted relative to one another. The pivot cradle bearing system 1 is part of an axial piston machine not shown further, i.e., an axial piston pump or an axial piston motor. The volume flow through the axial piston machine can be influenced with the aid of the pivot cradle bearing system 1. With regard to the basic structure and function of the pivot cradle bearing system 1, reference is made to the prior art cited at the outset.

[0035] The pivot cradle bearing system 1 includes a synchronization device, denoted 4 as a whole, which ensures that the pivoting of the cage segment 2 is coordinated with the relative movement between the bearing parts which can be adjusted with respect to one another. The synchronization device 4 comprises a pivot arm 5, which is mounted in the cage segment 2. Here, the pivot arm 5 and the cage segment 2 form a sliding bearing, namely a ball-and-socket joint 6. The ball-and-socket joint 6 is formed by an inner sliding bearing piece 8, which is provided directly by the pivot arm 5, and an outer sliding bearing piece 7, which is provided by a bearing plate 9 of the cage segment 2. The bearing plate 9 is slightly curved in accordance with the curvature of the cage segment 2 and merges into a cage strip 10. The cage strip 10 is connected to a further cage strip 11 via webs 12, wherein a cage pocket 3 is formed between two webs 12 that are adjacent in a circumferential direction. The webs 12 are oriented in parallel with the pivot axis of the pivot cradle bearing system 1. Overall, the cage segment 2 is therefore an integral plastic part.

[0036] The inner sliding bearing piece 8 formed by the pivot arm 5 is also referred to as a joint ball. Furthermore, the pivot arm 5 has an end ball 13, 14 at each of its two ends. The joint ball 13 arranged radially inside the cage segment 2, i.e., the end ball 13 that is spaced apart from the pivot axis of the pivot cradle bearing system 1 less than the cage segment 2, has a smaller distance from the joint ball 8 than the outer end ball 14. This is tantamount to an outer arm 15 of the pivot arm 5 being longer than an inner arm 16. The length of the arms 15, 16 is measured in each case starting from the center of the ball-and-socket joint 6, i.e. from the center of the spherical inner sliding bearing piece 8.

[0037] The inner sliding bearing piece 8 is designed to be symmetrical to an imaginary plane in which the center of the inner sliding bearing piece 8 lies and to which the longitudinal axis of the pivot arm 5—with respect to its arrangement according to FIG. 2—represents a surface normal. In contrast, the outer sliding bearing piece 7 is designed to be asymmetrical to the plane through the ball-and-socket joint 6: An inner portion 17 of the outer sliding bearing piece 7 provides an uninterrupted sliding surface. A spring arrangement 18, which provides a segmented sliding surface, adjoins the inner portion 17 radially outwardly—with respect to the pivot axis of the pivot cradle bearing system 1.

[0038] The spring arrangement 18 is part of a snap-action connection, denoted 19 as a whole, which is established between the cage segment 2 and the pivot arm 2. As an integral part of the bearing plate 9 and thus of the entire cage segment 2, the spring arrangement 18 in both exemplary embodiments comprises four spring tongues 20 which, starting from the inner portion 17, extend radially outwards. The spring tongues 20 together describe an annular shape, wherein a groove 21 is visible between each two spring tongues 20.

[0039] In the exemplary embodiment according to FIG. 1, the annular spring arrangement 18 is surrounded by an annular groove 22, which allows deflection of the individual spring tongues 20 during assembly. In this case, the complete spring arrangement 18 is arranged between the inner and outer surfaces of the bearing plate 9, each curved in accordance with the cage segment 2.

[0040] In contrast to this, the spring tongues 20 in the exemplary embodiment according to FIG. 4 project beyond the bearing plate 9. In this case, the inner portion 17 of the outer sliding bearing piece 7 formed by the bearing plate 9 is interrupted by a gap 23, so that the outer sliding bearing piece 7 describes an open annular shape, that is, a C-shape. In this case, there is no annular groove on the spring arrangement 18. Insertion chamfers on the individual spring tongues 20 present in the design according to FIG. 1 are also denoted by 24.

[0041] In both exemplary embodiments, the pivot arm 5, which is aligned radially—with respect to the pivot axis of the pivot cradle bearing system 1—is snapped into the outer sliding bearing piece 7 from the outside. Conversely, if necessary, non-destructive disassembly of the synchronization device 4 is possible by pulling out the pivot arm 5 to the outside. The two end balls 13, 14 have a smaller diameter than the joint ball 8 and thus do not hinder the assembly or disassembly of the metal pivot arm 5.

LIST OF REFERENCE NUMERALS

[0042] 1 pivot cradle bearing system [0043] 2 cage segment [0044] 3 cage pocket [0045] 4 synchronization device [0046] 5 pivot arm [0047] 6 ball-and-socket joint [0048] 7 outer sliding bearing piece [0049] 8 inner sliding bearing piece, joint ball [0050] 9 bearing plate [0051] 10 cage strip [0052] 11 cage strip [0053] 12 web [0054] 13 inner end ball [0055] 14 outer end ball [0056] 15 outer arm [0057] 16 inner arm [0058] 17 inner portion of outer sliding bearing piece [0059] 18 spring arrangement [0060] 19 snap-action connection [0061] 20 spring tongue [0062] 21 groove [0063] 22 annular groove