Schaeffler North America

Diaphragm clutch

Diaphragm clutch details


Function of the clutch
As a result of further developments in vehicle construction, today’s clutch components must satisfy a host of requirements that have a significant influence on the comfort behaviour of the vehicle. These include soft start-up, swift gear shifting, vibration damping and noise minimisation. The designers have squared up to these requirements. A modern clutch is typified by speed resistance, high transmission reliability, low overall height, low engagement forces and a long lifespan. The main components of a clutch are: Clutch pressure plate, disc flywheel and friction disc.

Together with flywheel and friction disc, the clutch pressure plate forms a friction system and is mounted to the flywheel by bolts in the housing. The pressure plate ensures that the engine torque is transferred via the friction disc to the transmission intake shaft. In the 70’s, the diaphragm spring clutch has consistently eliminated bolt springs from the passenger car. The contact force required for transferring engine torque is now provided by a slotted diaphragm spring. The diaphragm spring is significantly noticeable to the driver, because he needs to apply less pressure on the pedal due to the lower engaging force. Depending on clutch structure and actuation type, there is either the drawn or the compressed diaphragm spring clutch.

The LuK conventional diaphragm spring clutch is a compressed clutch. In this case, the polygon hub is bolted to the V-belt pulley on the crankshaft. The force flow is transferred through clutch housing into the flywheel bolted to it. The contact plate is attached to the clutch housing by plate springs. The cams on the contact plate project through the openings in the housing. The outer diaphragm spring are supported on these cam. It is attached to the housing by bolts and wire rings. The disengage bearing is arranged on the cylindrical outer diameter of the polygon hub and can move. The torque is transferred to the transmission intake shaft through the friction disc. This is a hollow shaft and sits on crankshaft stump between clutch and engine.


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