GB2310021A

GB2310021A - A reduced length clutch operating device having at least three circumferentially separated hydraulic subunits

Info

Publication number: GB2310021A
Application number: GB9702186A
Authority: GB
Inventors: Hans-Gerd Eckel; Anja Kunkel
Original assignee: Carl Freudenberg KG
Current assignee: Carl Freudenberg KG
Priority date: 1996-02-06
Filing date: 1997-02-03
Publication date: 1997-08-13
Anticipated expiration: 2017-02-03
Also published as: GB9702186D0; GB2310021B; DE19604159C2; FR2744504A1; DE19604159A1; FR2744504B1

Description

2310021 CLUTCH OPERATING DEVICE The invention relates to a clutch

operating device for a gear unit, comprising a release bearing surrounding a shaft and axially movable by means of a piston-and-cylinder =it which can be supplied with a fluid medium and is statically mounted, guide means being provided to suppress radially directed deflection movements of the release bearing.

A clutch operating device of this kind is known from DE 4001607. In this case the piston-and-cylinder unit is annular in shape and coordinated in close proximity with the surface of the shaft. The structural shape is therefore complicated. In addition, it takes up considerable space in the axial direction, inasmuch as the release bearing, the piston- andcylinder unit and the guide means are arranged one following the other in the axial direction.

It is an object of the invention to further develop clutch operating device of the abovementioned type in such manner that less space is required in the axial direction, while its manufacture is simplified.

This object is achieved, according to the invention, by a clutch operating device of the type initially mentioned, wherein the piston - and- cylinder unit comprises at least three subunits which are uniformly spaced apart circumferentially around the shaft, and the guide means are arranged in the gaps formed by the circumferential spacing between the subunits. Consequently, the piston-andcylinder units contained in the subunits no longer need to be annular in shape, so that their manufacture is substantially simplified. They are arranged at a radial distance from the shaft, so that it is possible to dispose the guide means and/or the release bearing in a position which is at least partly overlapped in the axial direction by the subunits. The space required in the axial direction is thus substantially reduced.

The subunits are grouped together in a casing and have a stationary mounting, so that they can easily be supplied with a fluid medium under pressure, for example a 5 hydraulic liquid or a gas.

The guide means may be formed by first finger extensions of a component comprising the subunits, raid finger extensions projecting parallel to the longitudinal direction of the shaft, and surrounding the release bearing in the region of an outer boundary surface. The release bearing is generally formed by a grooved ball bearing. Its purpose is to transmit to the clutch the axially directed operating forces of the subunits. Its arrangement in a position overlapping the first finger extensions in the axial direction gives rise to a reduction of axial structural length.

The outer boundary surface may also form a component of a support ring in which the release bearing is received. The resulting saving of space corresponds to that discussed above. In addition, the further advantage is gained that the release bearing may correspond to any standard construction. This is of great advantage in the procurement of spare parts.

The springs or resiliently mounted release elements distributed in the circumferential direction in a clutch do not normally have completely identical resilience. This results in a rotational tilting moment on the release bearing. In order to prevent frictional forces, increased because of this tilting moment, from impeding the axial movement of the release bearing in the operation of the clutch, or even causing self-locking, it has been found advantageous for the boundary surface to be spherically formed, at least in the subregions in contact with the first finger extensions. The release bearing held therein can - 3 thus adapt to the variations in resilience of the springs in the circumferential direction and follow the yielding spring ends such that the loading of the release bearing is balanced in the circumferential direction at all points on the circumference. This is of great advantage for obtaining improved durability of the release bearing.

The wobbling movement of the release bearing as the result of this rotational tilting moment is connected with continuous shifting of fluid between the individual piston- and- cylinder units. so that with small connection cross-sections between the pie ton-and- cylinder units good damping of this wobbling movement is achieved.

On the support ring second finger extensions can be provided, these extending outwards in the radial direction and being in engagement with the subunits. The diameter of the release bearing can be reduced accordingly, so that production costs are lowered.

The structural length is still further shortened if the second finger extensions are provided at that end of the ring which is remote from the subunits and if operating means contained in the subunits overlap the support ring as far as the second finger extensions.

The present invention will now be described in more detail, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows a clutch in longitudinal section containing a clutch operating device according to an embodiment of the invention; and Figure 2 shows a front view of the clutch operating device shown in Figure 1.

The clutch operating device shown in Figures 1 and 2 is intended for a gear unit which forms a component of the drive train of a motor vehicle. The clutch operating device comprises a release bearing 1 surrounding a shaft 2 and axially movable by means of a piston- and- cylinder unit which is supplied with a fluid medium, is statically mounted and which comprises three subunits 3 uniformly spaced apart circumferentially around the shaft 2. Guide means are provided in the gaps, formed by the circumferential spacing, between the subunits 3. The guide means are f ormed by f irst finger extensions 6 of a component comprising the subunits 3, said f inger extensions projecting parallel to the longitudinal direction of the shaft 2, and surrounding the release bearing 1 in the region of an outer boundary surface 5. The latter forms a component of a support ring 7 in which the release bearing 1 is received. The boundary surface 5 is spherically formed in the region in contact with the first finger extensions 6. The support ring 7, including the release bearing 1 contained in it, is thus able to follow, by a wobbling movement, the resilience, likewise varying in the circumferential direction, of the release elements 10 of the clutch when the latter is set in rotational motion. Even in the event of unfavourable conditions, complete balancing, in the circumferential direction, of the loading of the release bearing 1 in the axial direction is thereby ensured. In comparison with known structural forms, the diameter of the release bearing can be markedly reduced by this means.

Provided on the support ring 7 are second f inger extensions 8, these extending outwards in the radial direction and being in engagement with the subunits 3. Owing to the fact that the second f inger extensions 8 are provided at that end of the support ring 7 which is remote from the subunits 3 and that operating means 9 contained in the subunits 3 overlap the support ring 7 as far as the second finger extensions, a further reduction of the structural length required in the axial direction is achieved. The operating means 9 of the subunits 3 are formed by pistons in the exemplary embodiment illustrated. These pistons are mounted on compression springs in the respective cylinders. Wear on the clutch disc resulting from operation is thus automatically taken up without readjustment of the clutch being required.

Claims

1. A clutch operating device for a gear unit, comprising a release bearing surrounding a shaft and axially movable by means of a piston- andcylinder unit which can be supplied with a fluid medium and is statically mounted, guide means being provided to suppress radially directed deflection movements of the release bearing, wherein the pistonand-cylinder unit comprises at least three subunits which are uniformly spaced apart circumferentially around the shaft, and the guide means are arranged in the gaps formed by the circumferential spacing between the subunits.

2. A clutch operating device according to claim 1, wherein the guide means are formed by first finger extensions of a component comprising the subunits, said finger extensions projecting parallel to the longitudinal direction of the shaft and surrounding the release bearing in the region of an outer boundary surface.

3. A clutch operating device according to claim 2, wherein the boundary surface forms a component of a support ring in which the release bearing is received.

4. A clutch operating device according to either of claims 2 or 3, wherein the boundary surface is spherically formed, at least in the region in contact with the first finger extensions.

5. A clutch operating device according to claim 3 or claim 4 when dependent thereupon, wherein on the support ring second finger extensions are provided, these extending outwards in the radial direction and being in engagement with the subunits.

6. A clutch operating device according to claim 5, wherein the second finger extensions are provided at that end of the support ring which is remote from the subunits, and operating means contained in the subunits overlap the support ring as far as the second finger extensions.

7. A clutch operating device for a gear unit, substantially as described herein with reference to the accompanying drawings.