SG Transmission
Fail-Safe Brakes

When power is applied, the brake releases

Contact an expert to find out more about our Fail-Safe Brakes


Technical Information

SG Transmission fail-safe brakes can be used for all applications where rotating machines must be stopped quickly when switched off or when the power fails.  When power is applied, the brake releases and will stay in the off position allowing the machine to work or shaft to rotate.

Fail-safe brakes generate torque through the clamping together of friction surfaces, the method of clamping determines the two available types as spring applied or permanent magnet brakes.

It has been common place to apply spring applied brakes to static holding applications (rear of motors) and permanent magnet brakes to frequent on-off applications (rear of servo motors).

Spring applied brakes use multiple springs and a magnetic coil to clamp the rotor (with friction surfaces), when power is applied to the coil the magnetic force pulls an armature plate away from the friction surfaces. The springs in the coil are compressed and the rotor is free to rotate.

Permanent magnet brakes use a permanent magnet disc to generate magnetic energy which clamps the friction surfaces together against a stationary housing to give the required braking torque. When power is returned to the brake coil, the armature plate is released the shaft is free to rotate.

SG Transmission is able to offer three types of fail-safe brakes namely, spring applied, permanent magnet and the recently developed permanent magnet toothed brakes.

Customers should adopt good design practises when installing a fail-safe brake on a machine so as to eliminate any potential hazards to people and machines in the event of power failure.