Multiple Disk Electromagnetic Brake

Multiple Disk Electromagnetic Brake

Multiple disk brakes are used to deliver extremely high torque in minimal dimensional requirements. These brakes can be used either wet or dry, which makes them ideal to run in multiple speed gear box applications. Machine tool applications top the list where these brakes are used.


  • High torque/compact design: The multiplication of surface area in a multiple disk brake allows for one of the smallest torque to size ratios available.
  • Wet or dry application: Brakes can be used in an oil/gear box environment (wet), or as a stand alone clutch (dry).
  • Fast Response (wet): For fast response special channels are cut in the friction disks to allow the oil to flow faster.
  • High heat dissipation (wet): In an oil environment, the oil is used to take heat away from the friction disks for better heat dissipation.

How It Works

Engagement: Electromechanical brakes operate via an electric actuation, but transmit torque mechanically. When voltage/current is applied to the coil, it creates a magnetic field. This turns the coil into an electromagnet, which develops magnetic lines of flux. The magnetic flux attracts the armature to the face of the brake. As it does so, it squeezes the inner and outer friction disks together. The armature and hub are normally mounted on the shaft (customer supplied) that is rotating. Since the brake coil is mounted solidly, the brake armature, hub and shaft come to a stop in a short amount of time.

Disengagement: When current/voltage is removed from the brake, the armature is free to turn with the shaft. Springs hold the armature away from the brake surface when power is released, creating a minimal drag.

Cycling: Cycling is achieved by turning the voltage/current to the coil on and off. Slippage should occur only during deceleration. When the brake is engaged, there should be no slippage once the brake comes to a full stop.