GB2107818A

GB2107818A - Sliding sleeve for a clutch release bearing assembly

Info

Publication number: GB2107818A
Application number: GB08224701A
Authority: GB
Inventors: Manfred Brandenstein; Roland Haas; Ludwig Edelmann; Roland Bonengel
Original assignee: SKF Kugellagerfabriken GmbH
Current assignee: SKF GmbH
Priority date: 1981-08-27
Filing date: 1982-08-27
Publication date: 1983-05-05
Also published as: IT1210927B; JPS5846233A; IT8222996A0; GB2107818B; DE8128137U1; FR2512142B1; FR2512142A1; JPH0154575B2; IT8222735V0

Abstract

A sliding sleeve (1) for a clutch release bearing assembly is preferably made of plastics and has a plurality of axially extending grooves (26) in its radially outer surface. A thrust plate (23) has a plurality of inwardly extending tabs (25) engaging in the grooves. The walls of each groove are formed by resiliently deformable projections (32) which converge and then diverge along the length of the groove. The thrust plate is held against movement in one axial direction by the resilience of the projections (32) at the narrowest part of each groove. <IMAGE>

Description

SPECIFICATION Sliding sleeve for a clutch-release bearing assembly The present invention relates to a type of sliding sleeve for a ciutch-release bearing assembly, for example for a vehicle clutch, which comprises a hub body, preferably made of plastics material and at least one pressure plate secured to this hub body by a snap connection, which pressure plate has a bearing or contact surface, e.g. for the actuating lever of the clutch.

Patent specification DE 2240715 (Ferodo) discloses a sliding sleeve with a plastics hub body in which the clutch-actuating lever is applied against a metal pressure plate which is fixed by engagement behind two integrally formed straight bar-like projections arranged parallel to one another. This known sliding sleeve has the disadvantage that the projections can easily break off as a result of the constant loading and pressure plate is thus torn from its anchorage.

It is the object of the present invention to devise a sliding sleeve of the type defined initially, which consists of individual parts which can be produced cheaply and can be easily assembled, which are securely joined together and do not loosen or become detached, even if the hub material shrinks.

According to the present invention, this object is achieved in that the pressure plate is provided in the bore with radially inward directed tabs which under pre-load engage in axially extending grooves in the radially outer surface of the sliding sleeve and are retained therein in an axial direction by resilient projections.

Preferably the sliding sleeve is provided on its circumference with at least two axially extending, diametrically opposed grooves, the side walls of which facing one another, starting from the end face of the sliding sleeve until just before the end face of the flange, converge in axial direction and thereafter diverge as far as parallel-extending accommodating surfaces for the tabs of the pressure plate, the distance between the projections formed by the shaping of the side walls at the narrowest point being smaller than the width of the tabs.

In another aspect the invention provides, in combination, a sliding sleeve and a thrust plate for a clutch release bearing assembly, the thrust plate having an exposed axially facing contact surface, wherein the sliding sleeve has a plurality of axially extending grooves on its radially outer surface and resiliently deformable projections, and the thrust plate has a plurality of radially inwardly extending tabs engaging in the grooves with no circumferential clearance between each groove and its respective tab, the thrust plate being held against movement in one axial direction by the resiliently deformable projections.

An embodiment of the invention will now be described by way of example, reference being made to the accompanying drawings, of which: Figure 1 shows a side view, partly in section of a sliding sleeve with a clutch-thrust bearing, which on the side remote from the clutch has a snapfitted pressure plate; Figure 2 shows a view from the right hand end of the clutch-release assembly shown in Figure 1; Figure 3 shows a plan view of the clutchrelease assembly; and Figure 4 shows an enlarged view of part of the sliding sleeve in the vicinity of the pressure plate and the contact surface for clutch-thrust bearing.

The clutch-release bearing assembly shown in Figures 1 to 4 comprises a sliding sleeve 1 made of plastics material and a clutch-thrust bearing 2 which is positioned radially displaceably against a flange 3 of the sliding sleeve 1. The outer race 4 and the inner race 5 of the clutch-thrust bearing 2 are made from sheet metal and have tracks for balls 6 held in a cage 9. The outer race 4 has a convexiy shaped contact flange 7 for the diaphragm spring (not shown) of the clutch and is provided with an axially inward directed rim 8.

This rim 8 is flanged over radially outwards at the end and engages behind the inner race 5 with little clearance, so that the bearing races 4, 5, the balls 6 and cage 9 form an undetachable unit. A cover plate or disc 11 made of sheet metal is fitted on to the radially outward flanged rim 10 of the outer race 4, which cover plate extends radially inwardly close to the axially extending circumferential surface of the inner race 5 and forms therewith a narrow gap. The clutch bearing 2 is positioned with a radially outwardly extending flange 12 of the inner race 5 against the sliding sleeve 1 , the surfaces of which are reinforced for the application of the clutch-thrust bearing 2 and of the release lever (not shown).A damping ring 13 is arranged in the bore of the inner race 5, and has flexible inclined tongues 14 which, when the damping ring is centred, are spaced from the circumferential surface of the sliding sleeve 1 and resiliently resist the radial movement of the clutch bearing 2 upon exceeding a given amount of play, and also damp movements of the clutch bearing 2 relative to the sliding sleeve 1.

The sliding sleeve 1, made of plastics material, comprises a hub body 1 5 as well as the integrally moulded flange part 3, and on the side facing the clutch is provided with an annular sheet metal abutment plate of insert 1 6 embedded by casting or injection-moulding and of L-shape in crosssection. The insert 1 6 has an axially extended arm 1 7 provided with a plurality of apertures 1 8 arranged spaced apart on the periphery, whereby the sheet-metal insert 1 6 is securely anchored in the hub body 1 5 by the plastics material flowing therethrough during injection-moulding or casting.

The sheet-metal insert 1 6 has a radially directed arm 20 with an exposed surface 1 9 so that lowwear movement of the clutch bearing 2 on the sheet-metal insert 1 6 is achieved. Adjacent to the contact surface 1 9 the sheet metal insert 16 has a radially outer rim 21 which is axially offset in the direction away from the flange 3 and projects from the sliding sleeve 1. The offset portion 21 of the sheet metal insert 1 6 is provided with recesses 36, for example, four, into which engage respectively two diametrically opposed tabs 22 arranged on the periphery of the flange 12 of the inner race 5, so as to prevent the bearing race 5 from rotating relative to the sleeve 1.On the side of the flange 3 remote from the clutch, a pressure or thrust plate 23 with a contact surface 24 for the actuating lever (not shown) is positioned against the flange 3 of the sliding sleeve 1, said pressure plate having in the bore and spaced circumferentially apart four radially inward directed tabs 25. The tabs 25 engage under preload in axially extending grooves 26 in the radially outer surface of the sliding sleeve 1. The mutually facing side surfaces 27, 28 of the walls of the grooves 26 converge, starting from the end face 29 of the sliding sleeve 1, in the axial direction until just before the end face 30 of the flange 3 and thereafter diverge as far as the parallelextending accommodating side surfaces 31 for the tabs 25 of the pressure plate 23, so that mutually opposite projections 32 are formed.To enable the projections 32 to yield resiliently more easily, it is advantageous to provide besides the grooves 26 parallel-extending relief grooves 33 one on each side of the grooves 26 and to have the side surfaces 27, 28 converge towards one another radially outwardly, so that the distance apart of the side surfaces 27, 28 is the greatest in the vicinity of the groove base 34. Upon fitting the pressure plate 23 on to the circumference of the sliding sleeve 1, the projections 32 are pressed resiliently aside by the tabs 25 until the narrowest region 35 of the grooves 26 is reached. After the tabs 25 have passed this narrow region 35, the projections 32 return to their original position and fix the tabs 25 of the pressure plate 23, when positioned against the flange 3 of the sliding sleeve 1, between the parallel accommodating surfaces 31 of the groove 26 in an axial direction.

In this case it is advantageous to so choose the distance between the accommodating side surface 31 of the grooves 26 that the tabs 25 of the pressure plate 23 fit into the grooves 26 under pre-load, so that upon shrinkage of the plastics material it is not possible for any loosening or disconnection of the connection to occur.

Claims

1. Sliding sleeve for a clutch-release bearing assembly, for example for a vehicle clutch, which comprises a hub body, preferably made of plastics material, and at least one pressure plate secured to this hub body by a snap connection, which pressure plate has a contact surface, e.g. for the actuating lever of the clutch, characterised in that the pressure plate (23) is provided in the bore with radially inward directed tabs (25) which engage under pre-load in axially extending grooves (26) in the radially outer surface of the sliding sleeve (1) and are fixed therein in an axial direction by resilient projections (32).

2. Sliding sleeve as is claimed in claim 1, characterised in that it is provided on its radially outer surface with at least two axially extending diametrically opposed grooves (26).

3. Sliding sleeve as claimed in claim 1 or 2, characterised in that the mutually facing side surfaces (27, 28) of the grooves (26), for the formation of the projections (32), starting from the end face (29) of the sliding sleeve (1) until just before the end face (30) of the flange (3), converge in the axial direction and thereafter diverge as far as parallel-extending accommodating side surfaces (31) for the tabs (25) of the pressure plate (23), the clear distance between the projections (32) at the narrowest region (35) being smaller than the width of the tabs (25).

4. Sliding sleeve as claimed in one of claims 1 to 3, characterised in that the side surfaces (27, 28) of the grooves (26) converge radially outwardly, the distance of the side surfaces (27, 28) from one another being greatest in the vicinity of the groove base (34).

5. Sliding sleeve as claimed in one of claims 1 to 4, characterised in that near to the side wall of the grooves (26) relief grooves (33) are provided.

6. Sliding sleeve as claimed in one of claims 1 to 5, characterised in that the sliding sleeve (1) on the side facing the clutch is provided with a sheetmetal insert (16) embedded by casting or injection moulding and preferably of L-shape, the radially extending arm (20) of which insert protrudes from the flange (3) of the sliding sleeve (1) with a contact surface (19) and the outer rim of which has a cranked portion (21) which in perse known manner has recesses for accommodating tabs (22) arranged on the stationary bearing race (5).

7. Sliding sleeve as claimed in claim 6, characterised in that the axially directed arm (17) of the sheet metal insert (16) is provided with apertures (18).

8. In combination a sliding sleeve and a thrust plate for a clutch release bearing assembly, the thrust plate having an exposed axially facing contact surface, wherein the sliding sleeve has a plurality of axially extending grooves on its radially outer surface and resiliently deformable projections, and the thrust plate has a plurality of radially inwardly extending tabs engaging in the grooves with no circumferential clearance between each groove and its respective tab, the thrust plate being held against movement in one axial direction by the resiliently deformable projections.

9. A combination as claimed in claim 8, wherein the sliding sleeve is made of plastics and the thrust plate is made of metal.

10. A combination as claimed in claim 8 or 9, wherein the sleeve has at least one pair of diametrically opposed axially extending grooves.

11. A combination as claimed in claim 8,9 or 10, wherein the projections comprise the side walls of the grooves, and the facing side surfaces of the walls of each groove converge as they extend axially from one end of the sleeve toward the thrust plate then, before the thrust plate, the side surfaces diverge and then extend parallel with each other on each side of the respective tab, the internal width of each groove where the side surfaces start to diverge is less than the width of the respective tab and the internal width of the groove where the side surfaces are parallel with each other is such that there is no clearance between the side surfaces and the respective tab.

12. A combination as claimed in any one of claims 8 to 11, wherein the facing side surfaces of the walls of each groove converge as they extend radially outwardly.

13. A combination as claimed in any one of claims 8 to 12, wherein the sleeve has further axially extending grooves one on each side of the first said axially extending grooves.

14. A combination as claimed in any one of claims 8 to 13, wherein the sleeve is made of plastics and has a radially outwardly extending flange which is axially adjacent to and holds the thrust plate against movement in the other axial direction, and including an annular sheet metal abutment plate embedded in the sleeve, which abutment plate has a portion extending axially within the sleeve and a portion extending radially outwardly from the axially extending portion, which radially extending portion provides the flange with an exposed contact surface facing axially away from the thrust plate and which has a radially outer portion axially offset in the direction from the thrust plate toward the flange, which offset portion has recesses for reception of tabs of a bearing race ring.

1 5. A combination as claimed in claim 14 wherein the axially extending portion of the abutment plate has a plurality of apertures.

1 6. A combination of a sliding sleeve and a thrust plate for a clutch release bearing assembly substantially as herein described with reference to and as shown in the accompanying drawings.