FR2461158A1 - SELF-CENTERING CLUTCH STOP - Google Patents

Abstract

THE AXIAL TIGHTENING PROVIDING THE SELF-CENTERING OF THE STOP IS OBTAINED BY MEANS OF ELASTIC TAPES 16 AS AN INTEGRAL PART OF THE RADIAL PORTION 9 OF THE GUIDE SLEEVE 10 IN MOLDED SYNTHETIC MATERIAL. A SIMPLIFICATION OF MANUFACTURE AND ASSEMBLY IS THUS OBTAINED.

Description

The subject of the present invention is a clutch bearing comprising

  means ensuring its self-centering during declutching operations, in particular by means of an axial clamping device ensuring a certain friction force between a radial portion of one of the rings of a rolling bearing and a radial branch corresponding to a sleeve guiding the clutch release bearing on a guide tube. More specifically, the invention relates to a self-centering clutch stop for disc clutches and in particular for diaphragm clutches, said stop comprising a rolling bearing for example ball bearings and a guide sleeve allowing an axial sliding on a fixed guide tube, inside which the gearbox shaft rotates and allowing a substantially radial displacement of the assembly of the stop so as to bring it into a correctly centered position relative to the diaphragm, this position being maintained after

the declutching operation.

  Clutch stops of this type comprising a ball bearing or equivalent are provided with elastic means allowing a certain displacement of the stop relative to the shaft of the vehicle gearbox or relative to the guide tube on which moves the stopper. A radial branch of one of the bearing rings comes into frictional contact with a radial portion of the guide sleeve of the stop on the guide tube. During the first clutch release operations, the stop can therefore move in the radial direction, the respective surfaces of the bearing ring and the guide sleeve ensuring a certain friction under

  the action of the elastic clamping means.

  The guide sleeve is frequently made of synthetic material, for example by molding, which makes it possible to lighten the whole of the stop and improve the sliding of the

sleeve on the guide tube.

The object of the present invention is to simplify the manufacture of a clutch bearing of this type by reducing the number of parts to be assembled by integrating the means.

  axial clamping to the guide sleeve itself.

2461 15 &

  The self-centering clutch bearing according to the invention comprises a rolling bearing provided with an internal ring and an external rolling ring enclosing rolling elements as well as a guide sleeve which can slide axially on a tube. -guide and having a radial portion in friction contact with one of the rings of the bearing under the action of axial clamping means. According to the invention, the guide sleeve comprises elastic clamping means forming an integral part of said sleeve and cooperating with a radial branch of the bearing race which is in frictional contact with the

  radial portion of the guide sleeve.

  In a first embodiment, the elastic means

ques are arranged at the periphery of the radial portion of the sleeve and are curved substantially radially in order to enclose a radial branch directed towards the outside of

the bearing ring.

In another embodiment, the elastic means are on the contrary arranged substantially at the base of the radial portion of the sleeve and enclose a branch

radial directed towards the inside of the bearing ring.

In a preferred embodiment, the elastic means

  that comprise a plurality of tongues exerting a clamping action on the face of said radial branch of the bearing ring which is opposite to the face coming into contact with the radial portion of the sleeve in order to ensure the self-centering effect of the stop. The radial branch of the rolling ring then advantageously has radial protuberances each cooperating with one of the aforementioned tongues. To ensure the rotational locking of the assembly relative to the ring of the bearing, one of its radial protrusions preferably has a recess

  larger in size than the corresponding tab

  dante who comes to enter this recess.

In a variant, the deformable tongues forming an integral part of the guide sleeve, have a deformable curved portion allowing snap-on mounting and are arranged in line with windows

made in the cylindrical portion of the guide sleeve.

  The base of the curved portion of the tongues may be in the extension of the cylindrical portion of the sleeve or, on the contrary, of the radial portion of the sleeve. In another embodiment, the elastic means comprise a plurality of pins which can be introduced into recesses made in the radial branch of the ring of the bearing and provided at their ends with at least one latching spout. These pins are integral with a thinned portion of the radial portion of the guide sleeve so as to have the elasticity necessary for the operation of the

  self-centering stop of the invention.

  The invention can be applied, according to the embodiments, to a clutch stop whose inner ring is rotating and comes into contact with the diaphragm of the clutch or on the contrary to a clutch stop whose outer ring is rotating and cooperates with the diaphragm, the internal ring then being fixed. In all cases, the guide sleeve therefore cooperates with a radial branch of

the bearing ring which is kept fixed.

The invention will be better understood on studying the description.

tion of some embodiments of the invention taken by way of non-limiting examples and illustrated by the accompanying drawings, in which FIG. l is an axial sectional view of a first embodiment of a clutch stopper according to the invention in which the elastic tightening is done by means of a plurality of tongues cooperating with radial protrusions of the outer ring fixed; fig. 2 is a sectional view along II-II of FIG. 1; fig. 3 is a view in axial section of a second embodiment similar to that of FIG. l but suitable for the case where the inner ring is fixed and the outer ring rotating; fig. A is an axial section view of another embodiment in which the elastic tongues are arranged at the base of the radial portion of the guide sleeve; fig. 5 is an axial section view of a variant of the embodiment of FIG. 4; fig. 6 is an axial section view of another embodiment in which the elastic clamping means comprise clamping pins;

  and fig. 7 is a detail view in section along VII-

VII of fig. 6.

  As shown in Figs. l and 2 the clutch stop according to the invention comprises a ring

  inner bearing i with thin wall made by embou-

  weaving of a sheet or tube, having a tubular part 2 and a toroidal raceway 3 for a row of balls 4. The tubular part 2 is extended by a toric part 5 which can come into contact with the surface d 'a diaphragm or an equivalent element not shown in the figure, allowing actuation of a clutch. In this embodiment, the inner ring i is therefore rotated as soon as it enters

contact with the diaphragm surface.

The ball bearing of the clutch bearing is completed by a fixed outer ring referenced 6 as a whole, also with thin wall, produced by stamping a sheet or tube. The outer ring 6 has a toroidal raceway 7 for the balls 4 as well as a radial branch 8 directed towards the outside, being in relation to the balls 4, opposite the toric bearing surface 5 of the inner ring 1. A portion of the front annular surface of the radial branch 8 is in frictional contact with a radial annular portion 9 secured to a guide sleeve 10 preferably made of reinforced synthetic plastic material and capable of sliding on a tube- guide it

  shown in dashes in fig. 1.

The thrust rolling bearing is completed by a

  cage 12 which holds the balls 4 and a protective flange

tion 13 set on a radial branch 14 directed outwards

  of the outer ring 6. A wear plate 15 of structure

general annular structure in the form of a metal sheet covers the front face of the radial portion 9 of the sleeve 10 which is opposite the front face in contact with the radial branch 8 of the outer ring 6. During operation of the stop, a clutch release fork, not shown in the figure, comes to rest

on the wear plate 15 and thus causes a displacement

  axial of the entire stop relative to the tube-

  guide 11, the guide sleeve 10 sliding on said

  guide tube by its cylindrical portion.

  The elastic clamping between the radial portion 9 and the outer ring 6 is ensured by a plurality of elastic tongues 16 which form an integral part of the radial portion 9 of the guide sleeve 10. The elastic tongues 16 are arranged at the periphery of the radial portion 9 of the sleeve 10. They comprise a base part 17 directed substantially axially in the direction of the rolling bearing, that is to say opposite the wear plate 15. This base part 17 continues with a part curved 18 which itself ends with a tapered end 19 directed substantially radially inward. Thanks to this particular shape, the tongues 16 have a

suitable elasticity.

The number of elastic tabs 16 is chosen appropriately. In the example shown, the tabs

16 are eight in number.

The radial branch 8 of the outer ring 6 has at

regular intervals on its outer periphery of the protrusions

  radial sessions 20 in number identical to that of the elastic tongues 16 and each cooperating with one of said

elastic tabs 16.

To ensure the rotational locking of the assembly

  formed by the guide sleeve 10 and the fixed outer ring 6, one of the radial protrusions 20, referenced 20a, has a recess 21 visible in FIGS. 1 and 2, the dimensions of which are greater than those of the elastic tongues 16. The elastic tongue 16 which cooperates with the radial projection 20a can therefore penetrate with a certain clearance inside the recess 21. The end 19 of said elastic tongue 16 then abuts on the radial sides of the recess 21 preventing any rotation

relative to the fixed inner ring 6.

To facilitate mounting, each radial projection preferably has two chamfers 22 which allow the ends 19-of the elastic tongues 16 to be gradually deformed during mounting by relative rotation of the

  outer ring 6 relative to the guide sleeve 10.

  During the action of the control member of the clutch release bearing or clutch on the wear plate 15 by a thrust in the axial direction, the stop as a whole moves axially relative to the guide tube 11, the sleeve guide 10 sliding on the latter. The rolling bearing of the thrust bearing can move in a radial plane in order to center relative to the diaphragm of the clutch which comes into contact with the O-ring portion 5 of the inner ring 1, which is thereby rotated. Automatic centering is obtained by radial displacement of the bearing, the radial branch 8 of the fixed outer ring 6 being maintained in friction contact with the corresponding front wall

of the radial portion 9 of the guide sleeve 10. The friction

ment necessary for self-centering is generated by the elastic clamping effect in the axial direction obtained by the elastic tongues 16 cooperating with the radial protrusions 20. The displacement of the stop relative to the guide sleeve 10 is made possible by a suitable clearance remaining between the inner ring 2 and the cylindrical surface

of the guide sleeve 10.

  The variant of fig. 3 o identical pieces

bear the same references, does not differ from the embodiment

  tion of fig. 1 and 2 only by the fact that the inner ring of the bearing is fixed. The internal ring 23 therefore comprises in this variant a radial branch 24 directed towards the outside and playing exactly the role of the radial branch 8 of the external ring 6 of the embodiment of FIGS. 1 and 2. For this purpose, the radial branch 24 also has on its periphery a plurality of protrusions 25, one of which

has a blocking recess 26.

The bearing is completed by a rotating external ring 27 coming into contact with a toric portion 28 with the

surface of a diaphragm not shown in the figure.

  In this variant, the axial tightening ensuring self-

centering that the stop is therefore produced by the elastic tongues 16 integral with the radial portion 9 of the guide sleeve 10 which cooperate with the different protuberances

25 of the fixed inner ring 23.

  In the embodiment of FIG. 4 o identical parts have the same references, the guide sleeve 27 has a different structure. In this

  variant indeed, the elastic tongues 28 are dis-

  placed substantially at the base of the radial portion 29

of the guide sleeve 27. They can be deformed elas-

  by entering windows 30 adapted for this purpose, and made in the cylindrical portion 31 of the guide sleeve 27, said windows 30 being disposed at the adjacent end of the wear plate 15 of said

cylindrical portion 31.

  The fixed outer ring 32 comprises on the one hand a radial branch 33 on which the protective flange 34 is crimped and on the other hand a radial branch 35 directed inwards which comes into frictional contact with the opposite front face of the radial portion 29 of the guide sleeve 27. The internal periphery of the radial branch 35 which is in the form of a continuous flange in the example illustrated in FIG. 4 is clamped against the radial portion 29 by the clamping spouts 36

bent outwardly of the elastic tabs 28.

  Note that in this embodiment, each lan-

  elastic guettes 28 has a base portion 37 directed substantially radially inward and extending the radial portion 29. The base portion continues with a curved substantially axial portion 38 which ends in the clamping spout 36. When mounting the rolling bearing on the guide sleeve 27, the elastic tongues 38 are deformed in order to allow the radial branch 35 to pass, which is then enclosed by the nozzles 36 of the different

elastic tabs 28.

Although in the variant illustrated in FIG. 4 the radial branch 35 is in the form of a continuous flange, it will be understood that it would be possible to also provide a different structure for this radial branch in particular with a plurality of protrusions as in

  the embodiments of figs. 1, 2 and 3.

The variant of fig. 5 o identical parts

bear the same references, does not differ from the embodiment

tion of fig. 4 as by the shape of the elastic tongues.

In this embodiment, in fact, the elasticated tabs

that 39 which enclose the radial portion 35 of the fixed outer ring 32 are also arranged in the vicinity of the

  base of the radial portion 40 of the guide sleeve 41.

They can also be deformed during assembly in windows 42 made in a portion of the cylindrical part 43 of the guide sleeve 41 located in the vicinity of the base of the radial portion 40 on the side of the bearing.

stop. In this embodiment, the elasticated tabs

that 39 have a base portion 44 extending in a substantially axial direction the cylindrical portion 45 of the guide sleeve 41 which is located in line with the radial portion 40. The base portion 44 is bent substantially 900 radially outward in a thinned clamping portion 46 which acts on the radial branch 35 so as to exert an axial clamping against the radial portion of the guide sleeve 41. The elastic tongue 39

  continues with a portion 47 curved in a sensitive direction-

  axial with the free end slightly inclined towards

  the axis of the stop, penetrates inside the window 42.

  During the snap-fit mounting of the rolling bearing, the branch 35 gradually deforms the elastic tongues 39 by coming to bear on the inclined end of the

portions 47 which penetrate even more into the windows 42.

  As for the variant of fig. 4, the radial branch

  in the form of a collar could in this embodiment

  tion be replaced by a radial branch having a

plurality of growths as in the embodiments

tion of fig. 1, 2 and 3.

  In the embodiment illustrated in FIGS. 6 and 7 o identical parts have the same references, the elastic clamping means integral with the guide sleeve 48 consist of four pins 49 arranged in the vicinity of the base of the radial portion 50 of the guide sleeve 48. These pins 49 directed substantially axially towards the rolling bearing cooperate with the radial branch 51 of the fixed outer ring 52. To do this, each stud 49 comprises, as can be seen in particular in FIG. 7, two tongues 53 each provided with a clamping spout 54 and separated by a recess 55. The two tongues 53 are attached to a thinned part 56 of the radial portion 50 of the guide sleeve 48. The two clamping spouts 54 of the nipples 49 come to bear on the opposite side of the

  radial branch 51, the nipples 49 penetrating \ into recesses

  radial elements 57 formed in the bore of the radial branch 51. During the snap-fit mounting of the rolling bearing on the guide sleeve 48, the tongues 53 can deform thanks to the existence of the recess 55 in order to allow the introduction of nipples 49 in

recesses 57 and the snap-fit of the spouts 54.

  The elasticity of the tightening during operation of the stopper by self-centering is ensured in this variant by

thinned portions 56.

In all cases, a notable simplification is obtained.

  the manufacture and assembly of the stop, thanks to the integrated

gration of elastic clamping means allowing self-

centering, to the guide sleeve itself made preferably

  by molding a synthetic material.

246115 &

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Claims (14)

1. Self-centering clutch bearing comprising a rolling bearing provided with an inner ring and an outer bearing ring enclosing rolling elements, a guide sleeve which can slide axially on a tube-   guide and having a radial portion in contact with friction   ment with one of the bearing rings under the action of axial clamping means, characterized in that the guide sleeve comprises elastic clamping means forming an integral part of said sleeve and cooperating with a radial branch of said bearing ring in contact friction with the radial portion of the guide sleeve.   2. Clutch bearing according to claim 1, character-   laughed at by the fact that the elastic means are disposed at the periphery of the radial portion of the sleeve and are curved substantially radially in order to enclose a radial branch directed towards the outside of said ring of the bearing. 3. Clutch bearing according to claim 1, character-   laughed at by the fact that the elastic means are arranged at the base of the radial portion of the sleeve and are bent substantially radially to grip a radial branch   directed towards the inside of said bearing ring. 4. Clutch bearing according to any one of the claims.   previous cations, characterized in that the elastic means comprise a plurality of tongues exerting a clamping action on the face of said radial branch of the rolling ring which is opposite to the face in contact with the radial portion of the sleeve.   5. Clutch bearing according to claim 4, character-   laughed at by the fact that the radial branch of the rolling ring has cooperating radial protuberances each with one of the aforementioned tabs.   6. Clutch bearing according to claim 5, character-   laughed at by the fact that one of the protuberances has a recess of dimensions greater than those of the corresponding tongue thus ensuring a rotation blocking of the bearing ring.   7. Clutch bearing according to any one of the claims. cations 4 to 6, characterized in that the said tongues are deformable in order to allow snap-on mounting and for this purpose comprise a curved portion arranged in line with windows formed in the cylindrical portion of the guide sleeve. 8. Clutch bearing according to claim 7, character-   laughed at by the fact that the curved portions have a base part extending the cylindrical portion of the sleeve.   9. Clutch bearing according to claim 7, character- laughed at by the fact that the curved portions have a base portion extending inwardly the portion radial of the sleeve.   10. Clutch bearing according to any one of the res-   dications 1 to 3, characterized in that the elastic means comprise a plurality of pins which can be introduced into recesses in the radial branch of the bearing ring and provided at their end with at least one snap-on spout. 11. A clutch bearing according to claim 10, charac-   terrified by the fact that the nipples are integral with a   thinned portion of the radial portion of the guide sleeve.   12. Clutch bearing according to claims 10 or 11, characterized in that the nipples comprise two tongues each provided with a snap-fit spout and separated   by a recess improving elasticity. 13. Clutch bearing according to any one of the res-   dications previous, characterized in that said   bearing ring is the fixed outer ring. 14. Clutch bearing according to any one of the res-   dications 1 to 12, characterized in that said ring of the bearing is the fixed inner ring.