BEARING BUSH

Abstract

A bearing bush includes a core, an intermediate sleeve surrounding the core in a manner extending in a circumferential direction, an outer sleeve surrounding the intermediate sleeve in a manner extending in the circumferential direction, an elastomer body disposed between the intermediate sleeve and the outer sleeve, and a stop device. In embodiments, at axial ends of the core, the stop device protrudes from the core in a radial direction and limits a movement of the intermediate sleeve in an axial direction. The intermediate sleeve is mounted on the core and, relative to the stop device, in a circumferentially rotatable manner. The outer sleeve has several projections. The intermediate sleeve has at least one counter-projection which overlaps in the radial direction with the projections for limiting the axial deflection of the outer sleeve relative to the core.

Claims

1. A bearing bush, comprising a core, an intermediate sleeve surrounding the core in a manner extending in a circumferential direction, an outer sleeve surrounding the intermediate sleeve in the circumferential direction, an elastomer body disposed between the intermediate sleeve and the outer sleeve, and a stop device which, at axial ends of the core, protrudes from the core in a radial direction and limits a movement of the intermediate sleeve in an axial direction, wherein the intermediate sleeve is mounted on the core and, relative to the stop device, in a circumferentially rotatable manner, wherein the outer sleeve has several projections, wherein the intermediate sleeve has at least one counter-projection which overlaps in the radial direction with the projections for limiting an axial deflection of the outer sleeve relative to the core, and wherein the elastomer body has a protruding region, which protrudes beyond the intermediate sleeve in the axial direction and abuts against the stop device in a sealing manner.

2. The bearing bush according to claim 1, wherein the protruding region abuts against a circumferential face of the stop device.

3. The bearing bush according to claim 1, wherein the intermediate sleeve, on axial ends, has one limiting projection, respectively, which projects in the radial direction from the intermediate sleeve.

4. The bearing bush according to claim 1, wherein the protruding region is disposed between the stop device and the intermediate sleeve, between the stop device and the limiting projection.

5. The bearing bush according to claim 4, wherein the intermediate sleeve, at an axial face facing towards the stop device, and/or the stop device, at an axial face facing towards the intermediate sleeve, has a cutout in which the projecting region is disposed.

6. The bearing bush according to claim 1, wherein the projecting region has at least one sealing lip abutting against the stop device.

7. The bearing bush according to claim 1, wherein a surface between the intermediate sleeve and the core and/or between the intermediate sleeve and the stop device is provided with a lubricant.

8. The bearing bush according to claim 7, wherein the core and/or the intermediate sleeve have at least one recess for accommodating the lubricant, in a lubricant groove extending in the axial direction.

9. The bearing bush according to claim 8, wherein the recess is disposed at an axial outer face of the intermediate sleeve facing towards the stop device.

10. The bearing bush according to claim 1, wherein the elastomer body is attached by vulcanization to the outer sleeve.

11. The bearing bush according to claim 1, wherein the elastomer body is partially spaced apart from the outer sleeve and/or the intermediate sleeve by a second gap.

12. The bearing bush according to claim 11, wherein the elastomer body has a second sealing lip sealing the second gap.

13. The bearing bush according to claim 11, wherein the second gap is disposed between two projections and/or between two counter-projections.

14. The bearing bush according to claim 11, wherein the elastomer body has an additional padding member extending into the second gap.

15. The bearing bush according to claim 1, wherein the intermediate sleeve and/or the elastomer body has a slit extending in the axial direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0069] The invention will be explained in more detail with reference to the attached drawings. In the drawings:

[0070] FIG. 1 shows a schematic representation of a first embodiment of a bearing bush;

[0071] FIG. 2 shows a sectional view along the line of cut A-A from FIG. 1;

[0072] FIG. 3 shows an enlarged section of a second embodiment of the bearing bush;

[0073] FIG. 4 shows an enlarged section of a third embodiment of the bearing bush;

[0074] FIG. 5 shows an enlarged section of a fourth embodiment of the bearing bush;

[0075] FIG. 6 shows a schematic representation of the way in which the bearing bush according to FIG. 1 is produced;

[0076] FIG. 7 shows a schematic representation of a fifth embodiment of a bearing bush;

[0077] FIG. 8 shows a schematic representation of a sixth embodiment of a bearing bush;

[0078] FIG. 9 shows a cross sectional view along the cut B-B from FIG. 8;

[0079] FIG. 10 shows a schematic representation of a seventh embodiment of a bearing bush in a sectional view according to the line of cut B-B; and

[0080] FIG. 11 shows a schematic representation of an eighth embodiment of the bearing bush.

DETAILED DESCRIPTION

[0081] A bearing bush 10 has a core 11, an intermediate sleeve 12, an elastomer body 13, an outer sleeve 16, and a stop device 17. The core 11 serves for attaching the bearing bush 10 to a part of a vehicle. In particular, the core 11 has an axial bore through which a bolt for attaching the bearing bush 10 can be pushed.

[0082] Optionally, the core 11 is a single-part component. The stop device 17 may be pressed onto the core 11. In the embodiment illustrated in FIG. 1, the stop device 17 is formed by a first annular disk 17a and a second annular disk 17b which are each pressed onto the core 11. The stop device 17 serves for limiting an axial deflection of the intermediate sleeve 12 relative to the core 11.

[0083] By means of a first gap 18, the intermediate sleeve 12 is mounted on the core 11 in a circumferentially rotatable manner. Moreover, the first gap 18 extends between the intermediate sleeve 12 and the stop device 17. However, when the bearing bush 10 is mounted, the first gap 18 is closed to the extent that a clearance-free plain bearing is produced between the core 11 and the intermediate sleeve 12. Furthermore, when the stop device 17 is provided, the first gap 18 is made smaller to such an extent that a clearance-free plain bearing is also produced between the stop device 17 and the intermediate sleeve 12. Thus, the intermediate sleeve 12 is rotatably mounted also relative to the stop device 17. Thus, the first gap 18 is represented in an enlarged manner in the Figures. The first gap 18 is filled with a lubricant, particularly a lubricating grease, in order to provide a low-wear sliding mounting of the intermediate sleeve 12 on the core 11 and the stop device 17, or to set the sliding friction characteristics in a targeted manner. Furthermore, the coefficient of static friction and the coefficient of sliding friction can be adjusted by providing the lubricant, which can contribute to preventing noise.

[0084] In the embodiment shown in FIG. 1, the intermediate sleeve 12 has four counter-projections 22 projecting in the radial direction towards the outer sleeve 16. Two of the counter-projections 22, which are provided at the axial ends of the intermediate sleeve 12, may be configured as a first limiting projection 12a and a second limiting projection 12b. An axial outer face of the first and second limiting projections 12a, 12b facing towards the stop device 17, particularly the first annular disk 17a and the second annular disk 17b, is configured to be parallel to the extent of the first annular disk 17a and the second annular disk 17b, respectively.

[0085] The outer sleeve 16 has projections 21 projecting in the radial direction from the outer sleeve 16 towards the intermediate sleeve 12. The outer sleeve 16 has a first axial end portion 16a and a second axial end portion 16b, which are disposed at the axial ends of the outer sleeve 16 and are respectively situated opposite the first limiting projection 12a and the second limiting projection 12b.

[0086] The elastomer body 13 is provided between the outer sleeve 16 and the intermediate sleeve 12. The elastomer body 13 is attached to the intermediate sleeve 12 by vulcanization. In the embodiment illustrated in FIG. 1, a second gap 24 is provided between the elastomer body 13 and the outer sleeve 16, particularly in the region of the first end portion 16a, the second end portion 16b and between the projections 21. The second gap 24 preferably extends in the entire circumferential direction. Optionally, the projections 21 and the counter-projections 22 may also extend in the entire circumferential direction.

[0087] The elastomer body 13 has a protruding region 13a configured as a unit of the same material with the elastomer body 13. The protruding region 13a protrudes in the axial direction beyond the intermediate sleeve 12 and, in particular, beyond the first limiting projection 12a and the second limiting projection 12b. The protruding region 13a is provided on both axial ends of the bearing bush 10.

[0088] In the embodiment illustrated in FIG. 1, the protruding region 13a abuts against a circumferential face 17c of the stop device 17. In particular, the protruding region 13a has first sealing lips 14 abutting against the circumferential face 17c of the stop device 17. The contact surface between the protruding region 13a and the stop device 17 is reduced by providing the first sealing lips 14, which minimizes the abutting surface in the case of a rotation of the outer sleeve 16, and thus of the intermediate sleeve 12, relative to the core 11 and thus the stop device 17, thus offering a good sealing effect with, at the same time, a longer service life. The first gap 18 is sealed by means of the protruding region 13a, so that the lubricant cannot escape from the first gap 18 and the entry of dirt into the first gap 18 is prevented.

[0089] Optionally, the protruding region 13a has a second sealing lip 15, which abuts against the outer sleeve 16, particularly against the first axial end portion 16a and the second axial end portion 16b. The second sealing lip 15 seals the second gap 24, so that dirt cannot enter the second gap 24. Optionally, the first sealing lip 14 and/or the second sealing lip 15 are formed as a unit of the same material with the protruding region 13a.

[0090] As is apparent particularly from FIG. 2, the outer sleeve 16 has a two-part configuration. In particular, the two parts of the outer sleeve 16 consist of two half-shells which, in the mounted state, contact each other at an edge extending in the axial direction.

[0091] With the exception of the following differences, the embodiment of the bearing bush 10 shown in FIG. 3 matches the embodiment shown in FIG. 1. In this embodiment, the first gap 18 is not only provided between the two projections 21, but also between the two counter-projections 22. In this case, the second gap 24 is respectively disposed between the outer sleeve 16 and the elastomer body 13. Moreover, the elastomer body 13 has an additional padding member 26 with a convexly curved outer contour 26a. The additional padding member 26 extends into the second gap 24. In the embodiment illustrated in FIG. 3, the additional padding member 26 is respectively disposed between two counter-projections 22.

[0092] Furthermore, the thickness of the elastomer body 13 between the projection 21 and the counter-projection 22 is chosen in such a way that the elastomer body 13 is compressed between the projection 21 and the counter-projection 22. In the region in which the elastomer body 13 extends substantially in the radial direction, the elastomer body 13 is compressed between the projection 21 and the counter-projection 22. This means that in the case in which the outer sleeve 16 is not provided, the thickness of the elastomer body 13 is greater (see dashed line in FIG. 3) than in the case in which the outer sleeve 16 were provided. In the region of the extent in the axial direction, the thickness of the elastomer body 13 is greater than the distance between axial side surfaces of the projection 21 and the counter-projection 22.

[0093] Axial side surfaces of the projections 21 and/or of the counter-projections 22 extend almost perpendicularly to the axial direction, i.e. almost parallel to the radial direction. A deviation of up to 25, particularly up to 15, is possible, as is indicated in FIG. 1, for instance. Furthermore, the projection 21 and the counter-projection 22 overlap in the radial direction, so that an intermeshing between the projections 21 and the counter-projections 22 is accomplished.

[0094] The overlap in the radial direction between the projection 21 and the counter-projection 22 is as great as possible, so that as much of the elastomer body 13 as possible is effective between the projection 21 and the counter-projection 22 in the event of a deflection in the axial direction, whereby high axial rigidity can be obtained. Further, the axial rigidity of the bearing bush 10 may be increased by as many projections 21 and counter-projections 22 as possible being provided. The bias of the elastomer body 13 between the projection 21 and the counter-projection 22 in the axial direction also increases the axial rigidity.

[0095] The radial rigidity of the bearing bush 10 also increases with the increase of the axial rigidity. The second gaps 24 are provided in order to counteract this effect. In particular, the second gap 24 serves as a freewheel, so that it is predominantly the rigidity of the additional padding member 26 that is effective in the case of radial vibrations with an amplitude smaller than the thickness of the second gap 24 in the radial direction. For this purpose, the additional padding member 26 abuts against the projection 21 and thus against the outer sleeve 16. Only when the additional padding member 26 is fully compressed does the elastomer body 13 come into contact with the outer sleeve 16 in the region of the second gap 24, in which no additional padding member 26 is provided, so that this region of the elastomer body 13 is also effective. Thus, this procedure results in a progressive course of the characteristic curve of the rigidity. In particular, the increase in the radial rigidity accompanying the increase of the axial rigidity can be compensated by providing the second gap 24 with and without an additional padding member 26.

[0096] The embodiment of the bearing bush 10 shown in FIG. 4 matches the embodiment shown in FIG. 3. The fact that the additional padding member 26 is provided, not between two counter-projections 22, but between two projections 21, must be considered the sole difference.

[0097] The embodiment of the bearing bush 10 shown in FIG. 5 matches the embodiments shown in FIGS. 3 and 4, except for the fact that the elastomer body 13 is connected to the outer sleeve 16, and not to the intermediate sleeve 12. For example, the elastomer body 13 may be attached by vulcanization to the outer sleeve 16. Optionally, the protruding region 13a abuts against an axial outer face 16c of the outer sleeve 16; in particular, the protruding region 13a is attached to the axial outer face 16c of the outer sleeve 16 by vulcanization. Thus, the second gap 24 is provided between the elastomer body 13 and the intermediate sleeve 12, wherein the additional padding member 26 protrudes radially inwards into the second gap 24. The second sealing lip 15 also protrudes radially inwards from the elastomer body 13 and abuts against the intermediate sleeve 12.

[0098] The assembly of the bearing bush 10 according to FIG. 1 is depicted in FIG. 6. First, the core 11 is provided and the intermediate sleeve 12 is pushed onto the latter. Prior to the intermediate sleeve 12 being pushed on, the elastomer body 13 with the protruding region 13a has optionally been attached to the intermediate sleeve 12 by vulcanization. After the intermediate sleeve 12 has been pushed onto the core 11, the stop device 17 is connected to the core 11, e.g. by pressing it on. Then, the two parts of the outer sleeve 16 are placed on the elastomer body 13.

[0099] In all embodiments shown, the elastomer body 13 may optionally be attached by vulcanization to both the intermediate sleeve 12 and the outer sleeve 16, wherein the protruding region 13a, in particular, is also attached to the axial outer face 16c of the outer sleeve 16 by vulcanization. Furthermore, it is possible that the elastomer body 13 is attached by vulcanization exclusively to the outer sleeve 16.

[0100] The bearing bush 10 according to FIG. 7 matches the bearing bush 10 according to FIG. 1 and only differs therefrom in that the protruding region 13a does not abut against a circumferential face 17c of the stop device 17. Rather, the protruding region 13a abuts against an axial face of the stop device 17 that faces towards the intermediate sleeve 12. Furthermore, a cutout 28, in which the protruding region 13a is disposed, is respectively provided on the intermediate sleeve 12, particularly on the first limiting projection 12a and the second limiting projection 12b. Thus, the protruding region 13a is disposed between the intermediate sleeve 12, in particular the first and second limiting projections 12a and 12b, and the stop device 17, in particular the first annular disk 17a and the second annular disk 17b. In this case, the sealing lip 14 protrudes from the intermediate sleeve 12 in the axial direction towards the stop device 17.

[0101] With the exception of the following differences, the bearing bush 10 according to FIG. 8 matches the bearing bushes 10 according to FIG. 1. The bearing bush 10 according to FIG. 8 additionally has a recess 23 in the form of a lubricant groove 23a. The recess 23 serves for accommodating a lubricant and thus acts as a lubricant reservoir. The recess 23 may also be configured as a pocket. In the embodiment illustrated in FIG. 8, the lubricant groove 23a is disposed in the intermediate sleeve 12 and extends over the entire axial length of the latter. Furthermore, the lubricant groove 23a extends in the radial direction along the first and second limiting projections 12a, 12b. In this case, the lubricant groove 23a is optionally provided in a circumferentially uniformly distributed manner, as is apparent from FIG. 9.

[0102] With the exception of the following differences, the bearing bush 10 according to FIG. 10 matches the bearing bushes 10 according to FIG. 1. In the bearing bush 10 according to FIG. 10, a slit 30, which extends in the axial direction and/or at a slight angle to the axial direction, is provided. The slit 30 extends in the radial direction through the intermediate sleeve 12 and the elastomer body 13. By means of the slit 30, a bias can be applied after placement of the outer sleeve 16, and the radial thickness of the first gap 18 can be adjusted.

[0103] With the exception of the core 11 having a two-part configuration, the bearing bush 10 according to FIG. 11 matches the bearing bushes 10 according to FIGS. 1 to 10. A first core part 11a and a second core part 11b are separated from each other by a cut in the radial direction. In this embodiment, the stop device 17 is formed as a projecting member, which is integrally formed with the first core part 11a and the second core part 11b.