GB2227293A

GB2227293A - An hydraulic clutch-actuator having a plastics body and associated with a sheet metal clutch release bearing

Info

Publication number: GB2227293A
Application number: GB8928613A
Authority: GB
Inventors: Christoph Puhl; Ferdinand Eckert
Original assignee: FAG Kugelfischer Georg Schaefer KGaA; Kugelfischer Georg Schaefer and Co
Current assignee: IHO Holding GmbH and Co KG
Priority date: 1988-12-22
Filing date: 1989-12-19
Publication date: 1990-07-25
Also published as: FR2641049A3; DE8815881U1; GB8928613D0; FR2641049B3

Abstract

An hydraulic clutch-actuator comprising a clutch bearing (7), a slide sleeve (6) arranged to act on the bearing (7) and also serving as a piston (4), and an actuator casing (1) provided with a pressure-medium inlet (2). The casing (1) comprises a plastics material and includes a tubular chamber (3) for a pressure medium. The slide sleeve (6), which is constructed as a sleeve piston (4) provided with a seal (5), extends into and is axially displaceable in the tubular chamber (3). The slide sleeve (6) carries on its other end portion the clutch bearing (7). The clutch bearing (7) is provided with an outer race (8) formed of sheet-metal, without having been machined. The outer race (8), owing to its being spring-biased in an axial direction, is adjustable in a radial direction, rests against an abutment ring (12) and is surrounded by a sheet-metal cap (9), which makes the clutch bearing (7) a part of the actuator's constructional unit and which is secured to the sleeve (6) by means of a retaining ring (10). <IMAGE>

Description

An hydraulic clutch-actuator The present invention relates to an hydraulic clutch-actuator comprising a clutch bearing, a slide sleeve arranged to act on the bearing and also serving as a piston, and an actuator casing provided with a pressuremedium inlet.

An hydraulically operable clutch-actuator is known from DE-Gm 84 22 401. However, a disadvantage of this construction is that it has a massive structure for both the casing and the bearing, which are cast-steel products necessitating machining. This is difficult and expensive.

A clutch bearing made of sheet metal is also known from DE-Gm 19 75 536. The outer race of this bearing is surrounded by a sheet metal cap simultaneously serving as a slide sleeve. However, no provision is made for adjusting the outer race in a radial direction.

It is an aim of the present invention to provide a low-cost, light and reliable hydraulic clutch-actuator which can be manufactured substantially without having to be machined. The present invention also aims at rendering it possible for the bearing's outer race to be radially adjustable and for the actuator to form, until its installation, a single constructional unit.

Accordingly, the present invention is directed to an actuator having the construction set out in the opening paragraph of the present specification, in which a) the casing comprises a plastics material and includes a tubular chamber for a pressure medium; b) the slide sleeve, which is constructed as a sleeve piston provided with a seal, extends into and is axially displaceable in the tubular chamber; c) the slide sleeve carries on its other end portion the clutch bearing; d) the clutch bearing is provided with an outer race formed of sheet metal, without having been machined;; and e) the outer race, owing to its being spring-biased in an axial direction, is adjustable in a radial direction, rests against an abutment ring and is surrounded by a sheet-metal cap, which makes the clutch bearing a part of the actuator's constructional unit and which is secured to the sleeve by means of a retaining ring.

Advantageously, a bellows and a compression spring may be arranged on the sheet-metal cap and the casing to seal the actuator.

Also advantageously, the actuator may be provided with tape-like means for its protection during transport, the means being arranged so as to be snapped upon a first operation of the actuator.

The combination of a plastics casing, a plastics side sleeve, a sheet-metal bearing and a sheet-metal cap taken in conjunction with the tape-like means for the actuator's protection during transport provide a low cost and light clutch-actuator.

An example of an hydraulic clutch-actuator embodying the present invention is illustrated in the accompanying drawings, in which Figure 1 is an axial sectional view of the actuator; Figure la shows on a larger scale parts enclosed within the circle labelled X in Figure 1; and Figure 2 is a side view of the actuator including means for its protection during transport.

A plastics casing 1 is shown in Figure 1 provided with a pressure-medium inlet 2 and a tubular chamber 3, into which a stepped slide sleeve 6, which is constructed as a sleeve piston 4 provided with a seal 5, extends and is axially displaceable therein. The sleeve 6 carries a clutch bearing 7 on its other end portion, the clutch bearing 7 having an outer race 8 formed of sheet metal, without having been machined. The outer race 8 is surrounded by a sheet-metal cap 9 which makes the bearing 7 a part of the actuator's structural unit and which is secured to the sleeve 6 by means of a retaining ring 10.

A corrugated spring washer 11 is arranged axially between the cap 9 and the outer race 8 and biases the bearing 7 in an axial direction. Owing to this bias, the washer 11 pushes the bearing 7 against an abutment ring 12 joined to the cap 9 with the result that it is adjustable in a radial direction. A compression spring 13 is arranged between the cap 9 and the casing 1 and serves to cushion and to bias the bearing. A bellows 14 is fastened to the cap 9 and the casing 1 to seal the actuator.

As shown in Figure 2, the actuator is held together, until it is installed in a clutch, by tape-like means 15 provided to protect it during transport. The protecting means, which may be, for example, a small plastics tape, will be snapped when the clutch is operated for the first time. As soon as pressure is transmitted from the master cylinder of the clutch through the inlet 2, the pressure in the chamber 3 will also rise, with the result that the sleeve piston 4 will be axially displaced towards the left (viewing the actuator as in Figure 1), will take with it the bearing 7 mounted on the sleeve 6, and will thus push the inner race against the clutch.

When the pressure drops, the bearing and the sleeve piston will be moved back by the clutch spring (not shown) into their original positions.

Claims

1. An hydraulic clutch-actuator comprising a clutch bearing, a slide sleeve arranged to act on the bearing and also serving as a piston, and an actuator casing provided with a pressure-medium inlet, in which a) the casing comprises a plastics material and includes a tubular chamber for a pressure medium; b) the slide sleeve, which is constructed as a sleeve piston provided with a seal, extends into and is axially displaceable in the tubular chamber; c) the slide sleeve carries on its other end portion the clutch bearing; d) the clutch bearing is provided with an outer race formed of sheet metal, without having been machined; ; and e) the outer race, owing to its being spring-biased in an axial direction, is adjustable in a radial direction, rests against an abutment ring and is surrounded by a sheet-metal cap, which makes the clutch bearing a part of the actuator's constructional unit and which is secured to the sleeve by means of a retaining ring.

2. An hydraulic clutch-actuator according to claim 1, in which a bellows and a compression spring are arranged on the sheet-metal cap and the casing to seal the actuator.

3. An hydraulic clutch-actuator, in which the actuator is provided with tape-like means for its protection during transport, the means being arranged so as to be snapped upon a first operation of the actuator.

4. An hydraulic clutch-actuator substantially as described herein with reference to the accompanying drawings.