General Description Industrial: Electromagnetic Power Off Permanent Magnet Brake
Electromagnetic, direct current permanent magnet brakes operate similar to spring applied brakes but have some unique properties. Electromagnetic permanent magnet brakes are designed to stop and hold a rotating shaft or to simply hold the shaft in place. Their function is opposite from a traditional electromagnetic brake. When no electric power is going to the brake, the brake is considered engaged and holding. The two main reasons for using these brakes are safety and accuracy.
Ogura Features Industrial: Electromagnetic Power Off Permanent Magnet Brake
Small profile: Smaller diameter and are lighter in weight than spring applied brakes.
Zero backlash: Critical in medical and other high precision applications.
Fast response time: Brake coils are normally 90 or 24 volts DC. To reduce engagement time, a diode can be used to help collapse the magnetic field faster.
Variable torque: Permanent magnet brake torque can be controlled.
How It Works Industrial: Electromagnetic Power Off Permanent Magnet Brake
Engagement: Brakes are engaged magnetically and disengaged electrically. Powerful rare-earth magnets on the base of the brake create magnetic flux. This flux is free to travel through the coil shell creating a magnetic attraction between the coil shell and the armature.
Disengagement: When voltage or current is applied to the brake, the coil becomes an electromagnet. This produces magnetic lines of flux, which opposes and negates the force created by the permanent magnets. The spring pulls the armature away from the coil shell creating an airgap, so the hub and whatever is attached to the hub is free to rotate.