RELEASE BEARING

Abstract

Release bearings for actuating a clutch are provided, and may include a bearing ring arranged non-rotatably on a sliding sleeve mounted on a transmission input shaft and a rotatable bearing ring, which interacts with a spring of the clutch. A row of rolling elements may be arranged radially between the two bearing rings and have pressure lines oriented obliquely with respect to a bearing longitudinal axis. The rolling elements may each be bodies of revolution with a circular-arc-shaped generatrix, wherein a center angle between radii bounding the circular-arc-shaped generatrix is smaller than 180. The non-rotatable bearing ring may have a raceway shaped complementary to a shape of the rolling elements and may guide the rolling elements in an axial direction. The rotatable bearing ring may have a raceway shaped as a spherical surface with a sphere radius corresponding to the generatrix of the rolling elements.

Claims

1. A release bearing for actuating a clutch, comprising: a bearing ring, which is arranged non-rotatably on a sliding sleeve mounted on a transmission input shaft, a rotatable bearing ring, which interacts with a spring of the clutch, a row of rolling elements, which are arranged radially between the two bearing rings and have pressure lines oriented obliquely with respect to a bearing longitudinal axis, wherein the release bearing is configured to compensate for a reaction force, which is tilted relative to the bearing longitudinal axis and acts on the rotatable bearing ring, wherein the rolling elements are each in the form of bodies of revolution with a circular-arc-shaped generatrix, wherein a center angle between radii bounding the circular-arc-shaped generatrix is smaller than 180, wherein the non-rotatable bearing ring has a raceway which is adapted in complementary fashion to a shape of the rolling elements and which guides the rolling elements in an axial direction, and wherein the rotatable bearing ring has a raceway which is adapted to the shape of the rolling elements and which is in the form of a spherical surface with a sphere radius corresponding to the generatrix of the rolling elements.

2. The release bearing as claimed in claim 1, wherein the rolling elements have a shape of a barrel roller, wherein an inner bearing ring is designed as the non-rotatable bearing ring having a raceway that guides the rolling elements axially, and an outer bearing ring is designed as the rotatable bearing ring having a raceway in the form of a hollow sphere.

3. The release bearing as claimed in claim 1, wherein the rolling elements have a shape of a waisted roller, wherein an outer bearing ring is designed as the non-rotatable bearing ring having a raceway that guides the rolling elements axially, and an inner bearing ring is designed as the rotatable bearing ring having a spherical raceway.

4. The release bearing as claimed in claim 1, wherein the pressure lines of the rolling elements form an angle of between 75 and 85 with the bearing longitudinal axis.

5. The release bearing as claimed in claim 4, wherein the pressure lines of the rolling elements form an angle of 80 with the bearing longitudinal axis.

6. The release bearing as claimed in claim 1, wherein a possible tilting angle of the rotatable bearing ring relative to the non-rotatable bearing ring is limited by a stopper.

7. The release bearing as claimed in claim 6, wherein the stopper is formed by circlips arranged on an outer circumference of the bearing ring or on an inner circumference of the outer rotatable bearing ring.

8. The release bearing as claimed in claim 1, wherein the release bearing is sealed off on both axial sides by sealing ring washers, which are each mounted in a fixed manner on one of the bearing rings by one circumferential edge and rest sealingly on the other bearing ring with the other circumferential edge.

9. The release bearing as claimed in claim 6, wherein the stopper is formed by a retaining ring, a first end of which is connected to one of the two bearing rings in a manner which prevents relative rotation and translation and a second end of which is coupled to the other bearing ring in a manner which is subject to play and allows degrees of freedom in axial and radial directions.

10. A release bearing for actuating a clutch, comprising: a bearing ring arranged non-rotatably on a sliding sleeve mounted on a transmission input shaft; a rotatable bearing ring, which interacts with a spring of the clutch; a row of rolling elements arranged radially between the two bearing rings and having pressure lines oriented obliquely with respect to a bearing longitudinal axis; the rolling elements each being bodies of revolution with a circular-arc-shaped generatrix, wherein a center angle between radii bounding the circular-arc-shaped generatrix is smaller than 180; the non-rotatable bearing ring having a raceway shaped complementary to a shape of the rolling elements and which guides the rolling elements in an axial direction; and the rotatable bearing ring having a raceway shaped as a spherical surface with a sphere radius corresponding to the generatrix of the rolling elements.

11. The release bearing as claimed in claim 10, wherein the rolling elements have a shape of a barrel roller, wherein an inner bearing ring is designed as the non-rotatable bearing ring having a raceway that guides the rolling elements axially, and an outer bearing ring is designed as the rotatable bearing ring having a raceway in the form of a hollow sphere.

12. The release bearing as claimed in claim 10, wherein the rolling elements have a shape of a waisted roller, wherein an outer bearing ring is designed as the non-rotatable bearing ring having a raceway that guides the rolling elements axially, and an inner bearing ring is designed as the rotatable bearing ring having a spherical raceway.

13. The release bearing as claimed in claim 10, wherein the pressure lines of the rolling elements form an angle of between 75 and 85 with the bearing longitudinal axis.

14. The release bearing as claimed in claim 13, wherein the pressure lines of the rolling elements form an angle of 80 with the bearing longitudinal axis.

15. The release bearing as claimed in claim 10, wherein a possible tilting angle of the rotatable bearing ring relative to the non-rotatable bearing ring is limited by a stopper.

16. The release bearing as claimed in claim 15, wherein the stopper is formed by circlips arranged on an outer circumference of the bearing ring or on an inner circumference of the rotatable bearing ring.

17. The release bearing as claimed in claim 10, wherein the release bearing is sealed off on both axial sides by sealing ring washers, which are each mounted in a fixed manner on one of the bearing rings by one circumferential edge and rest sealingly on the other bearing ring with the other circumferential edge.

18. The release bearing as claimed in claim 15, wherein the stopper is formed by a retaining ring, a first end of which is connected to one of the two bearing rings in a manner which prevents relative rotation and translation and a second end of which is coupled to the other bearing ring in a manner which is subject to play and allows degrees of freedom in axial and radial directions.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The disclosure is explained in greater detail below by a number of illustrative embodiments. For this purpose, a drawing is attached to the description. In the drawing:

[0022] FIG. 1 shows an axial partial section through a release bearing having a barrel roller, in a tilted position,

[0023] FIGS. 2a-2b shows a release bearing according to FIG. 1 in different tilted positions on a reduced scale,

[0024] FIG. 3 shows a release bearing approximating to that in FIG. 1 having waisted rollers as rolling elements, and

[0025] FIG. 4 shows a release bearing approximating to that in FIG. 1 having a retaining ring.

DETAILED DESCRIPTION

[0026] The release bearing 2 illustrated in FIG. 1 comprises an inner bearing ring 4, which is arranged non-rotatably on a sliding sleeve (not shown), an outer bearing ring 6, which is rotatable relative to the inner bearing ring and interacts with a diaphragm spring (not shown) of a clutch, and rolling elements 10, which are arranged between the two bearing rings 4, 6 and are guided in a cage 8. The rolling elements 10, which are designed as barrel rollers in the present illustrative embodiment, roll, on the one hand, on a raceway 12, which is formed on the inner bearing ring 4, guides the rolling elements 10 axially and has a concave cross-sectional profile adapted to the barrel shape of the rolling elements. On the other hand, they roll on a hollow-spherical raceway 14, which is formed on the inner circumference of the outer bearing ring 6 and the radius R1 of which with respect to the longitudinal axis 15 of the bearing corresponds to the generatrix that defines the barrel shape of the rolling elements. The pressure line D of the rolling elements 10 forms an angle of about 80 with the longitudinal axis 15 of the release bearing 2.

[0027] During operation, the rotating outer bearing ring 6 can be tilted relative to the inner bearing ring 4. FIG. 1 shows the outer bearing ring 6 in an end position tilted to the left. This end position is determined by a circlip 16, which is arranged on the inner circumference of the outer bearing ring 6 and serves as a stopper. A circlip 17 arranged on the outer circumference of the inner bearing ring 4 delimits the raceway 12 thereof axially at the side.

[0028] In order to be able to design the release bearing 2 as a permanently lubricated bearing, it is sealed off on both axial sides by the sealing ring washers 18, 20, which are each mounted in a fixed manner on the rotating outer bearing ring 6 by their outer circumferential edge and rest sealingly on the non-rotatable inner bearing ring 4 by their inner circumferential edge. The contact surface 22 present on the inner bearing ring 6 is designed and dimensioned in such a way that the sealing rings 18, 20 make contact in every tilted position of the outer bearing ring 6 while providing full sealing, as can be seen in FIG. 1.

[0029] FIG. 2 shows the release bearing 2 according to FIG. 1 in various tilted positions, namely in an end position tilted to the left in FIG. 2a, in an un-tilted central position in FIG. 2b and in an end position tilted to the right in FIG. 2c. In particular, FIG. 2 also shows that the sealing ring washers 18, 20 rest against the associated contact surface 22 formed on the outer circumference of the inner bearing ring 4 in each of the tilted positions while providing full sealing.

[0030] FIG. 3 shows an embodiment of a release bearing 24 according to the disclosure in which the rolling elements 26 have the shape of a waisted roller. On the one hand, they roll on a raceway 30, which is formed on the outer bearing ring 28, guides the rolling elements axially and has a convex cross-sectional profile adapted to the shape of the rolling elements 26. On the other hand, the waisted rolling elements 26 roll on a raceway 34 in the form of a spherical surface, which is formed on the outer circumference of the inner bearing ring 32 and the radius R2 of which with respect to the longitudinal axis 15 of the release bearing 24 is equal to the radius of the generatrix that determines the shape of the contact surface of the rolling elements 26. In the illustrative embodiment according to FIG. 3, the outer bearing ring 28 is preferably designed as a bearing ring connected non-rotatably to a sliding sleeve, and the inner bearing ring 32 is designed as a rotating bearing ring which interacts with a diaphragm spring.

[0031] The circlips 16, 17 for limiting the tilting movement of the inner bearing ring 32 and the sealing ring washers 18, 20 at the axial ends for sealing off the release bearing 24 correspond to the elements described with reference to FIG. 1 and therefore do not need to be described again.

[0032] FIG. 4 shows an embodiment of a release bearing 2 according to FIG. 1 with bearing rings 4, 6 that are not tilted relative to one another, although the circlips 16, 17, which may be laborious to install, have been omitted. Instead, the release bearing 2 is held together in a very simple manner until it is installed as intended between the transmission and the internal combustion engine of a motor vehicle by just a single component, namely a retaining ring 35. This retaining ring 35 is pressed onto the outer circumference of the outer bearing ring 6 by its first end 36a in such a way as to be secure against relative rotation and translation. A shoulder 37, which extends in the radial direction, is provided on the other, inner bearing ring 4. The free edge 38 of the second end 36b of the retaining ring 35 is angled radially inward, wherein, in the installed state and without the two bearing rings 4, 6 being tilted relative to one another, the free edge 38 retains an axial play Sa relative to the shoulder 37 and the second end 36b and the free edge 38 retain a radial play Sr1 relative to the shoulder 37 and a radial play Sr2 relative to the inner bearing ring, respectively. This retention of axial and radial play Sa, Sr1, Sr2 ensures that the inner bearing ring 4 is coupled to the outer bearing ring 6 by the retaining ring 35 and that, despite this coupling, the two bearing rings 4, 6 can tilt relative to one another without hindrance. Moreover, this retention of play Sa, Sr1, Sr2 between the free end 36b and the free edge 38 relative to the shoulder 37 and to the inner bearing ring 4, respectively, leads to the formation of a gap or preliminary seal, thereby keeping coarse contaminants away from the sealing washer 18 and therefore prolonging the ability to function thereof.

REFERENCE SIGNS

[0033] 2 release bearing [0034] 4 inner bearing ring [0035] 6 outer bearing ring [0036] 8 cage [0037] 10 rolling elements [0038] 12 raceway on the inner bearing ring 4 [0039] 14 raceway on the outer bearing ring 6 [0040] 15 longitudinal axis of the release bearing [0041] 16 circlip [0042] 17 circlip [0043] 18 sealing ring washer [0044] 20 sealing ring washer [0045] 22 contact surface [0046] 24 release bearing [0047] 26 rolling elements [0048] 28 outer bearing ring [0049] 30 raceway on the outer bearing ring 28 [0050] 32 inner bearing ring [0051] 34 raceway on the inner bearing ring 32 [0052] 35 retaining ring [0053] 36a,b end [0054] 37 shoulder [0055] 38 free edge [0056] angle of the pressure line [0057] D pressure line [0058] R1 radius [0059] R2 radius [0060] Sa axial play [0061] Sr1,2 radial play