GB2055437A

GB2055437A - Devices for disengaging clutches

Info

Publication number: GB2055437A
Application number: GB8024633A
Authority: GB
Original assignee: Industriewerk Schaeffler OHG
Current assignee: IHO Holding GmbH and Co KG
Priority date: 1979-07-28
Filing date: 1980-07-28
Publication date: 1981-03-04
Also published as: DE2930674A1; FR2466667A1; IT8023738A0

Abstract

A disengaging device for a vehicle clutch comprises a release bearing 1 carried by a sleeve 2 slidable on a guide tube 4 fixed to a gearbox. A pressed sheet-metal actuating lever 3 has an arm 5 on each side of the sleeve 2 with gaps 8 between these arms and flats 6 formed on the sleeve 2 to prevent its rotation. To take up the play arising from the gaps 8, while accommodating manufacturing tolerances for the lever 3, a leaf spring 9 with arms 10 is mounted in each gap 8. <IMAGE>

Description

SPECIFICATION Devices for disengaging clutches The invention relates to devices for disengaging clutches.

According to the present invention, there is provided a device for disengaging a clutch, comprising a clutch release bearing mounted on a sliding sleeve for axial movement therewith, an actuating lever for axially moving the release bearing while preventing rotation of the sleeve, the lever having an arm on each side of the sleeve with a gap providing play between the lever arms and the sleeve, and a damping element to take up the play between at least one of the lever arms and the sleeve.

In a known disengaging device for a vehicle clutch, a sleeve carrying a release bearing is centred on the guide tube of the gearbox input shaft by means of the sliding sleeve and is located axially against the bearing or contact surfaces of an actuating lever and the tongues of the clutch diaphragm spring. Since the actuating lever, being a drawn sheet metal part, is produced with relatively large tolerances, it is not possible to avoid the occurrence of gaps between the bearing surfaces of the actuating lever on the clutch release bearing and the sliding sleeve, due to which gaps an undesirable play is produced.

This play, in particular in the unloaded state of the clutch release bearing, in combination with the vibrations induced by the speed of the engine, is not only the cause of the occurrence of a disagreeable rattling noise, but, more seriously, symptoms of wear appear to an increasing degree in particular at the bearing or contact surface of the sliding sleeve.and may lead to premature failure of the disengaging device.

The invention thus enables the undesirable play to be eliminated by simple means and the defects resulting from such play are avoided.

The damping element may be in the form of a shaped spring under initial tension and acting resiliently substantially at right angles in the gap between the sliding sleeve and the actuating lever.

Moreover, in advantageous manner, the form may be such that a leaf spring having a strap by means of which it is attached to the housing of the clutch release bearing serves as the shaped spring. Such a damping element is not only simple and cheap to manufacture, but also causes no additional difficulties when the disengaging device is fitted, since this element already forms a structural unit with the clutch release bearing.

In another advantageous embodiment, the shaped spring consists of at least two tongues bent out of a part formed as a clamp in the manner of a pipe hanger and clamped on the sliding sleeve. Such a shaped spring can also be produced cheaply from sheet metal and can be fixed in closely conforming manner to the sliding sleeve, so that in this case also the shaped spring already forms a structural unit with the clutch release bearing during transport and on fitting.

The sliding sleeve could also be formed of injection-moulded plastics material, at least one shaped spring being formed integrally therewith during the injection moulding. The advantage is thereby obtained that no additional component at all has to be assembled.

The tongues may be bent so that they are slightly S-shaped and arranged in alignment in mirror image form with respect to one another.

Such a design ensures that the gap between the sliding sleeve and the actuating lever is resiliently bridged in a satisfactory manner.

It may be advantageous to bend two more tongues out of the part formed after the fashion of a pipe hanger and clamped on the sliding sleeve, these two tongues being arranged in mirror image form with respect to the first two tongues. Such an arrangement has the advantage that even in the case of rather large tolerances the actuating lever is supported resiliently against the sliding sleeve on both sides.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, in which: Fig. 1 shows a device according to the invention partly in elevation and partly in longitudinal section; Fig. 2 is a section on the line Il-lI in Fig. 1; Fig. 3 shows a modification of part of Fig. 1; Fig. 4 shows an axial section at right angles to Fig. 3; Fig. 5 shows a modification to the view of Fig.

3; Fig. 6 is an end view of Fig. 5; Fig. 7 shows a modification of Fig. 6; and Fig. 8 shows another embodiment corresponding to the section according to Fig. 2.

Figs. 1 and 2 show a device for disengaging a vehicle clutch comprising a clutch release bearing 1 which is fixed on a sliding sleeve 2 and is arranged to be axially movable with it by means of an actuating lever 3 on the guide tube 4. The actuating lever 3 embraces the sliding sleeve 2 in the region of two flat faces 6 by means of two parallel arms 5 and bears against a radial abutment surface 7 of the clutch release bearing 1. Due to the cooperation between the flat faces 6 on the sliding sleeve 2, and the parallel arms 5 of the actuating lever 3, the sliding sleeve 2 is prevented by simple means from being able to turn or twist with respect to the actuating lever 3.

As shown in Figs. 1 and 2, the gaps 8 left between the arms 5 of the actuating lever 3 and the flat faces 6 of the sliding sleeve 2 are each bridged by a shaped spring 9 which is under initial tension. A similar spring is shown in Figs. 3 and 4.

The shaped spring 9 is formed as a leaf spring and has two tongues 10 extending substantially parallel to the flat faces and connected in the middle by a strap 11, the end 12 of which is bent in the form of a U to form a clip for mounting spring 9 on the flange 13 of the clutch release bearing 1.

Since, with such an arrangement, the arms 5 of the actuating lever 3 bear against the U-shaped bent ends 12 of the shaped springs 9, which are made of a hardened material, the further advantage is obtained that the housing of the clutch release bearing does not have to be subjected to a separate hardening treatment.

Figs. 5 and 6 show a shaped spring 14 which consists of two tongues 15 bent so that they are slightly S-shaped and which are arranged in alignment in mirror image form with respect to one another and are bent out of a part formed as a clamp after the fashion of a pipe hanger 16. The pipe hanger 1 6 is shaped in accordance with the contour of the sliding sleeve 2 and is clamped thereon by means of a screw 17.

The shaped spring 18 according to Fig. 7 differs from that according to Figs. 5 and 6 only in that, in mirror image form with respect to the two tongues 1 5, two more tongues 19 are also bent out of the part formed after the fashion of a pipe hanger 1 6.

Fig. 8 shows an embodiment in which the sliding sleeve 20 consists of plastics material.

Moreover, the shaped springs 21 are formed on the sliding sleeve 20 in one piece therewith in the region of the flat faces 22 by injection moulding.

Claims

1. A device for disengaging a clutch, comprising a clutch release bearing mounted on a sliding sleeve for axial movement therewith, an actuating lever for axially moving the release bearing while preventing rotation of the sleeve, the lever having an arm on each side of the sleeve with a gap providing play between the lever arms and the sleeve, and a damping element to take up the play between at least one of the lever arms and the sleeve.

2. A device according to claim 1, wherein the damping element is in the form of a shaped spring under initial tension and acting resiliently substantially at right angles to the gap between the sliding sleeve and the actuating lever.

3. A device according to claim 2, wherein a leaf spring having a strap by means of which it is attached to the housing of the clutch release bearing serves as the shaped spring.

4. A device according to claim 2, wherein the shaped spring consists of at least two tongues bent out of a part formed in the manner of a clamp engaged around the sliding sleeve.

5. A device according to claim 1, wherein the sliding sleeve is of injection-moulded plastics material and at least one shaped spring is formed integrally therewith.

6. A device according to claim 4, wherein the tongues are bent so that they are slightly Sshaped and arranged in alignment in mirror image form with respect to one another.

7. A device according to claim 6, wherein in mirror image form with respect to the two said tongues, two more tongues are bent out of the part formed in the manner of a clamp.

8. A device for disengaging a clutch, substantially as hereinbefore described with reference to Figs. 1 to 4, Figs. 5 and 6 or Fig. 7 or Fig. 8 of the accompanying drawings.