GB2153478A

GB2153478A - A clutch release bearing

Info

Publication number: GB2153478A
Application number: GB08431786A
Authority: GB
Inventors: Patrick Muller
Original assignee: Automotive Products PLC
Current assignee: Automotive Products PLC
Priority date: 1984-01-12
Filing date: 1984-12-17
Publication date: 1985-08-21
Also published as: GB8431786D0; FR2558228B1; FR2558228A1

Abstract

The clutch release bearing comprises a first member 13 to which a releasing force is to be applied by a fork, a second member 14 for applying the releasing force to a clutch diaphragm 15 and ball bearings 16 through which the releasing force is transmitted from the first member to the second member. The first member 13 includes an eccentric weight 23 which biases the first member into a desired rotary position on a guide 10 during assembly to align lugs on the first member with the fork. <IMAGE>

Description

SPECIFICATION A clutch release bearing The invention relates to a clutch release bearing and is particularly but not exclusively concerned with a clutch release bearing of a motor vehicle transmission.

Clutch release bearings for cetain vehicles are actuated by a release fork which is driven by a cable or the slave cylinder of a hydraulic clutch operating circuit. One of the problems which occurs during assembly of the transmission components concerns alignment of the clutch release fork with fork locations on the release bearing. As access is sometimes quite restricted it can be difficult to hold the bearing in a desired rotational position in alignment with the fork and an object of the present invention is to provide a clutch release bearing which will simplify such assembly.

According to the invention there is provided a clutch releasembearing comprising a first member to which a releasing force is to be applied by a fork or other means, a second member for applying said releasing force to a clutch element, and bearing means through which the releasing force is transmitted from the first member to the second member, the first member including bias means for biasing the first member into a predetermined rotary position on a guide during assembly to align said first member with the fork or other means.

The bias means preferably comprises a weight arranged eccentrically on the first member. By using an eccentric weight, the first member will be turned by gravity about the guide to position location means on the first member in a desired position relative to said fork or other means which in use engages said location means.

The first member may comprise a sleeve which axially slidable on said guide and may also include a coaxial race mounted on the sleeve.

The race may include location means for the fork or other means, which location means is aligned with said fork or other means by the eccentric weight.

Preferably the race and sleeve are normally urged axially together by flexible means which facilitates limited axial mis-alignment of the race and sleeve. In such a case the flexible means may comprise a leaf spring which may, for example, be secured to the race by said eccentric weight.

The weight may be carried by a radial extension formed on the race.

Preferably the second member defines a further race for the bearing means and is secured axially to a diaphragm-type clutch spring. The second member may include a portion defining said further race and another portion axially fast therewith, the other portion extending through the diaphragm for applying said release force to one side of the diaphragm. Preferably the said other portion locates the diaphragm between a surface on said other portion and resilient means which biases the diaphragm and surface towards each other. The resilient means may have location means thereon which locates it relative to the second member or diaphragm. Conveniently the resilient means may be a belleville spring. The other portion of the second member may be a sheet metal element axially fast with the first said portion of the second member.

Preferably the second member applies the release force to the clutch element through a bearing engaging the clutch element. The said other portion of the second member may locate the bearing engaging the clutch element in such a case.

Clutch release bearings in accordance with the invention will now be described by way of example with reference to the accompanying drawings in which; Figure 1 is an end elevation of a clutch release bearing in accordance with the invention, Figure2 is a cross-section of the clutch release bearing in Figure 1 on the line ll-il in Figure 1 carried by a guide sleeve and engaging a clutch diaphragm, Figure 3 is an end view of another type of clutch release bearing in accordance with the invention co-operating with a clutch release fork, and Figures 4 to 6 are cross-sections similar to Figure 2 of further types of clutch release bearing in accordance with the invention.

Referring first to Figures 1 and 2, a tubular guide 10 is carried in known manner by a gearbox (not shown) of a vehicle transmission. The guide is coaxial with a drive input shaft (also not shown) for the gearbox. The guide 10 carries a clutch release bearing 12 which comprises a first member 13 which fits with working clearance on the guide 10, a second member 14 associated with a clutch diaphragm 15 and ball bearings 16 between the first and second members. In detail, the first member comprises a sleeve 17 and a coaxial outer race 18, the sleeve having an annular end flange 19 formed with an annular rim 20. The outer race 18 is formed with a radial extension 22 to which is fitted a weight 23. The weight has a stem 24 which passes through the extension 22 and through a leaf spring 25. The stem 24 is peened over at 26 to hold the weight and leaf spring securely to the outer race.The rim 20 of the flange 19 is cut away to leave a recess 27 in which the leaf spring 25 locates with working clearance.

The leaf spring engages the flange 18 and normally draws the outer race 18 against the rim 20. The resilient interconnection facilitates a certain amount of axial misalignment between the sleeve 17 and outer race 18. The second member comprises an inner race 28 which is axially fast with a ball holder 29. The inner race 28 is formed with a peripheral groove 30 in which a bead 32 on the ball holder snap fits. The ball holder 29 is formed with circumferentially spaced slots 33 to leave fingers 34 which pass through radial slots 35 in the diaphragm 15. The fingers 34 are turned outwardly so as to locate balls 36 as shown. A belleville spring 37 is arranged under compression between the diaphragm 15 and the inner race 38 and urges the inner race and diaphragm 15 against the balls 36. The ball bearings 16 are located between the inner and outer races which may be formed as metal pressings.The outer race is formed with locating lugs 38 for a clutch release fork, end portions of which are indicated at 39 in Figure 1.

The clutch release fork is mounted adjacent the clutch release bearing for operation by the normal slave cylinder of a hydraulic clutch operating circuit.

During assembly of the clutch release bearing the first member 13 once located on the guide 10 will be rotated on the guide by weight 23 as gravity urges the weight into its lowest position, the sleeve 17 being freely rotatable on the guide. The lugs 38 are so positioned that with the weight 23 in its lowest position the lugs will align with the fork ends 39 when the fork is assembled. Location of the fork against the lugs 38 is then a simple operation requiring no manipulation of the first member to effect alignment.The fork applies a releasing force in direction R to the outer race 18 which causes the sleeve 17 to slide along the guide 10, the force being transmitted to the diaphram through bearings 16, inner race 28, ball holder 29 and balls 36 to release the clutch (not shown) Figure 3 illustrates a clutch release bearing in which the lugs 38 on the outer race 18 are positioned to engage an inclined fork 31. It can be appreciated from Figure 3 that the position of the weight 23 can be selected appropriately during manufacture to suit any desired fork orientation In Figures 4 to 6 the first members 13 illustrated are the same as that in Figure 1 and will not be described again. However, Figures 4 to 6 illustrate a variety of second members 14 applicable to diaphram type clutches.

In Figure 4 the second member comprises an innner race 28 which carries an annular sheet metal pressing 40 in a peripheral groove 42. The pressing 40 has a series of circumferentially spaced dimples 43 which locate balls 36. A belleville spring 44 located in a further peripheral groove 45 in the inner race 28 urges the diaphragm 15 and pressing 40 against the balls 36. The spring 44 has a series of tongues 46 which locate in slots 35 in the diaphragm.

In Figure 5 the inner race 28 is axially fast with a series of out-turned fingers 50 which pas through slots 35 in the diaphragm and locate balls 36. The diaphragm 15 and fingers 50 are held against the balls 36 by a belleville spring 52 having a series of tongues 53 which locate in respective slots 54 defined between fingers 50.

In Figure 6 the inner race 28 carries a sheet metal pressing 60 which defines a ball holding groove 62 and has a cylindrical body 63. The body 63 has one or more sprags 64 pressed inwardly and which snap-fit into one or respective recesses 65 on the inner race. A belleville spring 66 similar to that in Figure 4 is provided in this embodiment.

Claims

1. A clutch release bearing comprising a first member to which a releasing force is to be applied by a fork or other means, a second member for applying said releasing force to a clutch element, and bearing means through which the releasing force is transmitted from the first member to the second member, the first member including bias means for biasing the first member into a predetermined rotary position on a guide during assembly to align said first member with the fork or other means.

2. A clutch release bearing according to claim 1 in which the bias means is a weight arranged eccentrically on the first member.

3. A clutch release bearing according to claim 2 in which the first member comprises a sleeve which is axially slidably on said guide and a coaxial race mounted on the sleeve for said bearing means.

4. A clutch release bearing according to claim 3 in which the race includes location means for the fork or other means, which location means is aligned with said fork or other means by the eccentric weight.

5. A clutch release bearing according to claim 2, 3 or 4 in which the race and sleeve are normally urged axially together by flexible means which facilitates limited axial mis-alignment of the race and sleeve.

6. A clutch release bearing according to claim 5 in which the flexible means comprises a leaf spring.

7. A clutch release bearing according to claim 6 in which the leaf spring is secured to the race by said eccentric weight.

8. A clutch release bearing according to any of claims 2 to 7 in which the weight is carried by a radial extension formed on the race.

9. A clutch release bearing according to any preceding claim in which the second member defines a further race for the bearing means and is secured axially to a diaphragm-type clutch spring.

10. Aclutch release bearing according to claim 9 in which the second member includes a portion defining said further race and another portion axially fast therewith, the other portion extending through the diaphragm for applying said release force to one side of the diaphragm.

11. A clutch release bearing according to claim 10 in which the said other portion locates the diaphragm between a surface on said other portion and resilient means which biases the diaphragm and surface towards each other.

12. A clutch release bearing according to claim 11 in which the resilient means has location means thereon which locates it relative to the second member or diaphragm.

13. Aclutch release bearing according to claim 12 in which the resilient means is a belleville spring.

14. A clutch release bearing according to claim 10,1112 or 13 in which the other portion of the second member is a sheet metal element axially fast with the first said portion of the second member.

15. Aclutch release bearing according to any preceding claim in which the second member applies the release force to the clutch element through a bearing engaging the clutch element.

16. A clutch release bearing according to claim 15 when appendant to any of claims 10 to 14 in which said other portion of the second member locates the bearings engaging the clutch element.

17. A clutch release bearing constructed and arranged substantially as described herein with reference to Figures 1 and 2, Figure 3, Figure 4, Figure 5 or Figure 6 of the accompanying drawings.