They are switched altermately in order to accelarate or decelerate the output shaft. Torque transmission is achieved using friction.

    As well as the basic versions with free drive and output shafts and hollow shafts, clutch-brake combinations are also available with built-on three-phase AC motors and with helical or worm gearboxes mounted at the output end. The drives can be used in either a horizontal or vertical mounting position. Using preassembled units significantly reduces design costs for new developments and the time spent on mounting.

    Friction clutches and brakes are subject to a certain amount of wear which is dependent on the switching energy used. Automatic adjusting devices (which are susceptible to faults) are no longer required, thanks to the the wear resistant, asbestos-free friction linings used.