Since clutches are subject to wear during use in the vehicle, LuK, as the first clutch manufacturer, put a great deal of effort into developing a type of wear compensation system for the clutch, and put it in production in 1995. The self-adjusting clutch SAC uses a load sensor (sensor-diaphragm spring) to activate its wear compensation by turning a ramp ring. This compensation mechanism has made it possible to decrease operating loads. The compensation for the clutch wear has also made it possible to increase the clutch service life by about 1.5 times without any significant change in the operating load over the service life. The wear adjustment system of the SAC – consisting of the sensor-diaphragm spring (load sensor) and the deep-drawn steel adjuster ring – is characterized by very high functional precision. Since a harmonic operating load curve is required in addition to comfortable clutch operation, the SAC was created with the capacity to be tuned to specific vehicle characteristic curves. One of the mechanisms that makes this possible is the compensation spring, which can generate the flatter characteristic curves that are frequently desired.
The newly developed SAC II.
provides a further optimization of the system. Here, the load sensor is not comprised of a second diaphragm spring, but rather of the sensor fingers formed from the main diaphragm spring and special tangential leaf springs with a decreasing characteristic curve.