ZF Hysteresis Brakes and Clutches
Electrically operated hysteresis brakes and clutches allow contact-free torque transmission. As a result they are not susceptible to wear and need no maintenance. Slip torque and synchronous torque can be adjusted to any level between zero and the maximum, dependent only on the set magnet coil current. The set torque, meanwhile, is largely none speed dependent.
Because there are no wearing parts Hysteresis Brakes and Clutches do not produce the dust associated with traditional brakes and clutches make them ideal for use in food, medical or other environments where cleanliness is essential
ZF Hysteresis brakes cover nominal torques between 0.05 and 40 Nm, and torques of up to 760 Nm if an integral planetary step is added. Although the same size as their standard counterparts, the high performance range can easily cope with double the slip power, even four times the slip power for brief periods. This means that braking power totalling up to 2000 W can be achieved.
There are four types of hysteresis clutches available, covering nominal toques of 0.4 to 12 Nm.
Two types of controller are available - the ZFERM is a multi-function unit that can operate in closed or open loop and accept feedback inputs from dancer arm, roll follower, load cell, ultrasonic sensor, speed sensor or any 0-10 volt source. The ZFIS controller is a simple driver card for any of the ZF units and can be configured with potentiometer input for a pre-set level or accept a 0-10 volt or 4-20mA signal from an external source.