GB2114697A - Clutch release bearing assembly - Google Patents

Abstract

A clutch release bearing assembly for a motor vehicle comprises a bearing element (15) disposed between an operating element (13) and an actuator (14). The bearing element can move transversely in any direction relative to the operating element and the actuator, and swivel means (42) are provided permitting a relative inclination between the bearing element (15) and the support guide (11) for the actuator (14). These swivel means are disposed directly between the bearing element (15) and the actuator (14). This arrangement can compensate for substantial defects in parallelism between the hub of the clutch and the axis of the support guide. The operating element (13) is carried by an axially slidable support member (19). <IMAGE>

Description

SPECIFICATION Clutch release bearing assembly U.K. Patent Application No. 8202535 (publication No. 2092256A) describes a clutch release bearing assembly for a motor vehicle, comprising an operating element, carried by an axially-slidable support member, which is acted upon by a control member, in practice a disengaging fork, an actuator, forming an extension-piece, which is mounted to slide axially on a support guide and which, under the action of the operating element, is capable of acting on the disengaging device of a clutch, and a bearing element interposed between the operating element and the actuator, which can move transversely in any direction, either relative to the operating element or relative to the actuator.

This arrangement, which is therefore characterised in that the bearing element can move transversely in any direction relative to two separate elements, namely the operating element and the actuator, between which it is disposed, facilitates the required self-centering between the actuator and the disengaging device on which it acts, even if, as is the case in question, this actuator axially forms an extension-piece engaged to slide on a separate support guide.

This earlier patent application also makes provision for the use of swivel means to permit a relative inclination between the bearing element and the support guide for the actuator, in practice the hub of the clutch in question, and thus overcomes the consequences of a possible defect in parallelism between the axis of this hub and that of the support member for the operating element.

In the embodiment described more particularly in the aforementioned patent application, these swivel means are disposed between the operating element and its support member.

Although, in practice, under normal operating conditions, this arrangement has given and is still capable of giving satisfaction, it has been shown that, under particularly difficult test conditions, which are generally more severe than these normal operating conditions, and in particular if the parallelism defect between the axis of the hub of the clutch and that of the support member for the operating element is very pronounced, and/or if the disengaging device of the clutch in question, and especially that part of the latter on which the actuator bears (for example the radical ends of the fingers of a diaphragm spring) is out of true, deficiencies can be observed.

The reason for this is that, in the event of a parallelism defect between these two axes and/or a deformation defect of the disengaging device, the bearing element, which, in contact with the actuator, centres itself on the latter, causes an oscillatory movement relative to the axis of the support member for the operating element.

In order to accommodate the parallelism defect between the axes in question and/or the deformation defect of the disengaging device, this bearing element, like the operating element and the actuator, within the limits of the sliding play of the latter on its support guide, becomes inclined relative to the axis of the support member for the operating element.

Because of the resulting skew relative to the said axis, the operating element, in contact with the swivel means of its support member, is the subject of relatively large cyclic oscillatory forces.

This is more especially the case because the corresponding swivel means, by virtue of their construction, necessarily have a relatively large overall diameter since it has been developed around a central dead zone permitting the axial engagement of the operating element on its support member, and because the operating element is at a distance from the actuator.

This, it is not infrequent to observe seizing of the operating element relative to its support member, at the location of the corresponding swivel means, or even more or less pronounced punching of the central part of this operating element involved in the formation of these swivel means, due to a fatigue phenomenon associated with the speed of rotation of the assembly.

The present invention provides in general terms an arrangement which overcomes these disadvantages and thus increases the operating life of the bearing assembly in question.

Accordingly, the present invention provides a clutch release bearing assembly suitable for a motor vehicle, of the kind which uses an axially slidable operat;ng element carried by a support member, which operating element Is acted upon by a control member, which in practice is a disengaging fork, an actuator, forming an extension-piece, which is mounted to slide axially on a support guide and which, under the action of the operating element, is adapted to act on the disengaging device of a clutch, and a bearing element which is disposed between the operating element and the actuator, and which can move transversely in any direction, either relative to the operating element or relative to the actuator, in combination with swivel means permitting a relative inclination between the bearing element and the support guide for the actuator, the swivel means being disposed directly between the bearing element and the actuator.

By virtue of such an arrangement, only the actuator forming an extension-piece becomes inclined relative to the axis of the support member in the event of a parallelism defect between this axis and that of the clutch and/or a deformation defect of the disengaging device, the bearing element, like the operating element, in contrast remaining perpendicular to the axis of the support member.

Thus, the bearing element is no longer the cause of any particular force between the operating element and its support member.

In practice, according to a preferred embodiment, the bearing element and the actuator each possess, opposite one another, a transverse plate, and the swivel means disposed between them are formed between the transverse plates, preferably in the immediate vicinity of the axis of the assembly, either one of the transverse plates being plane while the other, for contact with the first, possesses a projecting boss.

As a result, the contact zone between the bearing element and the actuator is virtually a point contact, and, even in the event of a parallelism defect between the axes in question, the contact zone is formed over a circumference which is always of very small diameter.

The effect of such a parallelism defect are thereby advantageously minimised.

French Patent No. 1,366,763 made provision for the use of swivel means between an actuator, forming an extension-piece, and a bearing element. However, the bearing assembly in this patent is very different from that forming the subject of the present Application.

In fact, the bearing element in the said patent is directly carried by the corresponding disengaging fork, so that, because of the pivoting of the latter, a relative movement, which necessarily generates wear, takes place between the two constituent elements of the corresponding swivel means, one of which is necessarily plane.

None of this applies to the clutch release bearing assembly according to the invention, there being no relative movement developed between the two constituent members of the swivel means used, both of which could be spherical if desired.

The two assemblies are therefore very different.

In order that the invention may be more fully understood, embodiments in accordance therewith will now be described by way of example, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a view in axial section of a clutch release bearing assembly; Figure 2 is a similar view to that of Figure 1 showing a modified embodiment; Figures 3, 4 and 5 each show part of Figure 1 on a larger scale, each relating respectively to a modified embodiment; and, likewise, Figures 6 and 7 each show part of Figure 1, each relating respectively to other modified embodiments.

Figures 1 and 2 show a clutch release bearing assembly of the kind described in U.K. Patent Application No. 8202535.

Figures 1 and 2 partially show, in broken lines, at 10 the clutch housing, at 11 the hub of the clutch, and at 12 its disengaging device, which in known manner, may simply consist of the radial ends of the fingers of a diaphragm spring.

As decribed in the aforesaid patent application, the clutch release bearing assembly provided for acting on this disengaging device 12 uses an operating element 13, which, carried by a support member 19 mounted to slide axially in a bore 20 in the housing 10, is acted upon by a control member, in practice a disengaging fork (not shown), an actuator 14, forming an extensionpiece, which is mounted to slide axially on a support guide, formed in practice by the hub 11, and which, under the action of the operating element 13, is capable of acting on the disengaging device 12, and a bearing element 15, which interposed between the operating element 13 and the actuator 14, can move transversely in any direction, either relative to the operating element 1 3 or relative to the actuator 14.

In the embodiment shown in Figure 1, the operating element 13 is in-the form-of a support plate of suitable shape, which, by means of a central recess 21 bordered by an axial flange 22, is firmly fixed to the support member by tight engagement on an axial extension 23 of the support member, and which, in the case of a bearing assembly with residual load ensuring a permanent axial force on the assembly in the direction of the disengaging device 12, simply bears axially against a transverse shoulder 25 on the said support member 19.

In a variant, shown in Figure 2, an elastic ring 26 can be provided for axially retaining this operating element 13, if appropriate, the said elastic ring 26 being engaged in a groove 27 provided for this purpose at the periphery of the extension 23 of the support member 1 9.

This ring can be, for example, a metal split ring or a ring made of elastomer.

In the case where the elastic ring 26 is a ring made of elastomer, the operating element 13 is engaged by hand on the elastic ring 26 by means of its central recess 21, passing over the said ring by virtue of elastic deformation of the latter, and it is immobilised in rotation relative to the support member 19 by a pin (not shown); in such a case, the operating element 1 3 can be without an axial flange 22, and the axial extension 23 of the support member 19 can be shorter.

In-the embodiments shown, the bearing element 1 5 is a standard ball bearing with an inner ring 16 and an outer ring 17.

By means of its inner ring 16, it is capable of acting on the actuator 1 4 in ways described in detail below, and, by means of its outer ring 17, it bears axially on the support plate forming the operating element 13.

Moreover, it is connected axially to this operating element 1 3 via a housing 29 and is thus carried by the latter.

In the embodiments shown, this housing 29 comprises, on the one hand, an elastic front wall 30, which, for example, undulates in a circular pattern in the manner of the undulating washers sold commercially under the name "ONDUFLEX", as shown, and by which it bears axially on the edge of the outer ring 17 of the bearing element 1 5, opposite the operating element 13, and, on the other hand, a plurality of lugs 31, which are distributed in a circular arrangement and by which it engages with hooks 32 provided for this purpose on the said operating element 13, on the outer periphery of the support plate forming this operating element.

The inner ring 16 of the bearing element 15 is axially spaced apart from the operating element 1 3, that peripheral area of this operating element 1 3 against which the said bearing element 1 5 bears by means of its outer ring 1 7 being axially offset relative to its main part.

Moreover, this peripheral area, which is delimited by an axial rim on which the hooks 32 are formed at intervals, is sufficiently developed in the radial direction to allow the bearing element 1 5 to move transversely in any desired direction relative to the operating element 13.

Briefly, as in the aforementioned patent application, the clutch release bearing assembly according to the invention has sustained selfcentering, it being possible for the bearing element 1 5 to move transversely in any-direction relative to the operating element 13, and the axially-acting elastic washer formed by the front wall 30 of the housing 29 keeping this bearing element 1 5 in position when the latter is not otherwise subject to any force.

Also as in the previous patent application, the actuator 14 possesses an axial wall 35 by means of which it is engaged to slide on the hub 11 forming its support guide, and, at that end of this axial wall which is opposite the bearing element 15, is formed with a radial flange 37 by means of which it is capable of acting on the disengaging device 12.

In the embodiment shown in Figure 1, this flange 37, which is directed radially outwards and which, for contact with the disengaging device 12, has a curved profile transversely, is integral with the axial wall 35.

According to the invention, swivel means are provided in order to permit a relative inclination between the bearing element 1 5 and the hub 11 forming the support guide for the actuator 14, the said swivel means being disposed directly between the said bearing element 1 5 and the said actuator 14.

In practice, in the embodiments shown, the bearing element 15 and the actuator 14 each possess a transverse plate facing one another, namely a transverse plate 40 for the bearing element 15 and a transverse plate 41 for the actuator 14, and the swivel means are formed between the transverse plates 40, 41 which this bearing element 1 5 and this actuator 1 4 thus possess.

In the embodiments shown, these transverse plates 40 and 41 are both solid, that is to say that they do not possess any recess in their central zone, and the swivel means disposes between them can thus be formed in the immediate vicinity of the axis of the assembly.

In the embodiments shown, either one of these transverse plates 40, 41 is plane, and the swivel means disposed between the said transverse plates 40, 41 result from the fact that, for contact with the one which is plane, the other possesses a projecting boss 42, which is preferably rounded.

In the embodiments illustrated in Figures 1 to 4, this boss 42 is formed on the transverse plate 40 of the bearing element 1 5, while the transverse plate 41 of the actuator 14 is plane.

For example, in Figures 1 and 2, this boss 42 results from a local, overall spherical deformation of the transverse plate 40.

In a modified embodiment, as shown in Figures 3 and 4, it can be formed by a part suitably added to this transverse plate 40, such as a bush riveted to the latter, as in Figure 3, or a bead crimped in this transverse plate 40, as in Figure 4.

Preferably, and as shown, the bush shown in Figure 3 is rounded, as mentioned above.

In the embodiments shown in Figures 1 and 2, the transverse plate 40 of the bearing element 1 5 is formed- by a piece added to the inner ring 16 of the latter.

For example, as in Figure 1, this transverse plate 40 possesses axially, at its periphery, a flange 44 by means of which it is force-fitted to the inner ring 16 of the bearing element 15, and more precisely into a clearance 45 provided for this purpose at the inner periphery of this inner ring.

This transverse plate 40 is then preferably made of metal, for example of suitably treated steel.

In a modified embodiment, as shown in Figure 2, the transverse plate 40 of the bearing element 1 5 possesses axially, at its periphery, at least two elastically deformable lugs 46, the ends of which possess a projecting bead, preferably bevelled, as shown, and by means of which it is snapped onto the inner ring 16 of the said bearing element 1 5.

For this purpose, this transverse plate 40, which, as previously, is engaged in a clearance 45 provided at the inner periphery of this inner ring 1 6, at one of the axial ends of the latter, bears against a transverse shoulder 48 limiting this clearance 45, and, at its other axial end, the inner ring 16 possesses, for snap-on co-operation with the elastically deformable lugs 46, a bevel 49 complementary to the corresponding bevel in the said lugs.

The transverse plate 40 is then preferably made of synthetic material.

As a corollary to this, in the embodiment shown in Figure 1, the transverse plate 41 of the actuator 14 is integral with the corresponding axial wall 35, the assembly comprising this axial wall 35, the radial flange 37 and the transverse plate 41 of the actuator 1 4 being produced conjointly by stamping.

In a modified embodiment, as shown in Figure 2, the radial flange 37 and the transverse plate 41 of the actuator 14 can form parts which are separate from the axial wall 35 of the latter, these parts being suitably added, for example by crimping, as shown, to the corresponding ends of this axial wall 35.

Whatever the case may be, and as can easily be understood, in the event of a parallelism defect between the axis of the support member 1 9 for the operating element 13, on the one hand, and the axis of the hub 11 forming the support guide for the actuator 1 4 on the other hand, and also in the event of a deformation defect of the disengaging device of the clutch in question, the said actuator, by virtue of the swivel means according to the invention, can freely become inclined relative to the bearing element 15, in contact with the boss 42 on the latter, and within the limits of its sliding play on the said hub 11, in order to compensate for such a defect.

As shown in Figure 2, swivel means formed, for example, by an annular bead of rounded crosssection, 60 provided at the inner periphery of the axial wall 35 of the actuator 14, for contact with the hub 11 can also be provided between this actuator 14 and this hub 11, in combination with the swivel means provided, according to the invention, between the bearing element 1 5 and the actuator 14.

The inclination of the actuator 1 4 relative to the bearing element 1 5 is thereby advantageously facilitated, as is also its sliding on the hub 11.

In the embodiment illustrated in Figure 5, the boss 42 is formed on the transverse plate 41 of the actuator 14.

In the case in question, this is a local overall spherical deformation in the latter.

However, the modified embodiments illustrated in Figures 3 and 4 can also be applied to this transverse plate 41.

In the modified embodiments illustrated in Figures 6 and 7, the transverse plate 40 of the bearing element 1 5 is integral with the inner ring of the latter, either by being attached to that axial end of this inner ring 1 6 which is closer to the actuator 14, as in Figure 6, or by being attached to that axial end of this ring 16 which is further from this actuator 14, as in Figure 7.

In the embodiments shown, the boss 42 is formed on this transverse plate 40 of the bearing element 1 5 by local deformation of the latter.

However, as previously, the modified embodiments illustrated in Figures 3 and 4 can equally well be applied.

The present invention is not moreover limited to the embodiments described and shown, but encompasses any modified procedure and/or modified combination of their various elements within the scope of the appended claims.

Claims (13)

1. A clutch release bearing assembly of the kind comprising an operating element carried by an axially slidable support member which operating element is adapted to be acted upon by a control member such as a disengaging fork, an actuator comprising an extension-piece, which is mounted to slide axially on a support guide and which, under the action of the operating element is adapted to act on the disengaging device of a clutch, and a bearing element located between the operating element and the actuator, which bearing element is movable transversely in any direction, either relative to the operating element or relative to the actuator, in combination with swivel means permitting a relative inclination between the bearing element and the support guide for the actuator, said swivel means being disposed directly between said bearing element and said actuator.

2. A clutch release bearing assembly according to Claim 1, wherein the bearing element and the actuator are each provided with a transverse plate, and said transverse plates face one another and the swivel means are formed between the said transverse plates.

3. A clutch release bearing assembly according to Claim 2, wherein the swivel means are formed in the immediate vicinity of the axis of the assembly.

4. A clutch release bearing assembly according to Claim 3, wherein at least one of the transverse plates is solid.

5. A clutch release bearing assembly according to Claim 3 or Claim 4, wherein either one of the transverse plates is plane, and the swivel means disposed between the said transverse plates comprise, for contact with the plane transverse plate, a preferably rounded projecting boss on the other transverse plate.

6. A clutch release bearing assembly according to Claim 5, wherein said boss results from local deformation of the transverse plate in question.

7. A clutch release bearing assembly according to Claim 5, wherein said boss is formed by a part suitably added to the transverse plate in question, such as, for example, a riveted bush or crimped bead.

8. A clutch release bearing assembly according to any one of Claims 2 to 7, in which the bearing element is formed by a ball bearing, and the transverse plate of said bearing element is formed by a part added to the inner ring thereof.

9. A clutch release bearing assembly according to Claim 8, wherein the transverse plate of the bearing element is provided with an axial flange by means of which it is force-fitted to the inner ring of this bearing element.

1 0. A clutch release bearing assembly according to Claim 9, wherein the.transverse plate of the bearing element is formed axially with at least two elastically deformable lugs by means of which it is snapped onto the inner ring of this bearing element.

11. A clutch release bearing assembly according to any one of Claims 2 to 7, in which the bearing element is formed by a ball bearing, and the transverse plate of said bearing element is integral with the inner ring thereof.

12. A clutch release bearing assembly according to any one of Claims 1 to 11, wherein swivel means are also provided between the actuator and its support guide.

13. A clutch release bearing assembly substantially as hereinbefore described with reference to Figure 1, Figure 2, or Figure 1 as modified by any one of Figures 3, 4, 5, 6 or 7 of the accompanying drawings.