Release bearings

The functional purpose of release bearings

The clutch transfers the force of power, the release bearing guarantees function. The release bearing is the connecting link between the rotating clutch pressure plate for the engine, and the fixed release mechanism on the gearbox side. Nowadays virtually only pressure ball bearings are used to transfer the release forces over to the clutch pressure plate.

Construction forms

Releaser with graphite ring

Releaser with graphite ring
Swivel-mounted in a release-fork

Releaser centrally positioned on a toggle

Releaser centrally positioned on a toggle
The release bearing balls are set into the circumferential inner ring.

Lower revs increase the longevity of the release bearing.

Releaser with self-centring bearing form

Releaser with self-centring bearing form
The releasers are designed as self-centring components (radial movement approx. 1.5 mm) to balance unavoidable tolerances between the engine block and the gearbox cover. Initial clutch actions lead to an automatic centralisation on the lip of the membrane spring.

Releaser for pull clutches

Releaser for pull clutches:

  1. with fixed connection
    The releaser is fastened to the membrane spring of the pressure plate by means of a release ring.
  2. with a snap-on connection
    The release ring is mounted onto the lip of the membrane spring via a shaft spring. Upon activation of the releaser, the conical shaped inner ring will snap onto the release ring. The torsion force is transferred via a special wire ring. During dis­assembly, the connection between the pressure plate and the releaser can be broken using the wire ring.

Releaser with integrated driver cylinder

Releaser with integrated driver cylinder
Releaser and driver cylinder, as a complete unit, encompass the gearbox input shaft. A big advantage of this type of design is an automatic replacement as the clutch lining wears out.