Overview of Permanent Magnet BrakesAt SEPAC, we provide innovative electromagnetic clutch and brake solutions for a wide range of applications and industries. One of our standard product offerings is permanent magnet brakes, which have a power-off design that ensures safe stopping and/or holding of a load in the absence of power.

How Do Permanent Magnet Power-Off Brakes Work?

Our PMB series permanent magnet power-off brakes feature a magnet body assembly that when installed is fixed to stop it from rotating and an armature assembly containing the friction surface which is secured to the shaft via a hub. In the absence of power (i.e., no power is applied), the magnetic field emitted by the permanent magnet generates a force that is strong enough to attract the armature and produce torque. This engages the fixed and rotating components, which stops and/or holds the load. In the presence of power (i.e., power is applied), the flux path of the permanent magnet is reversed, which reduces the holding force. The loss of force prompts the diaphragm spring to release the armature, which, in turn, releases the brake. This allows the shaft to rotate freely.

Features of PMB Series Permanent Magnet Power-Off Brakes

PMB series brakes are made with samarium cobalt rare earth magnets, which makes them highly resistant to demagnetization. Some of their other key features include:

  • Steel on steel friction surface
  • True zero backlash is standard
  • Higher Torque vs Diameter than spring engaged brakes
  • Large magnet body “thru” bore (allowing cables to be run through)
  • Simple Installation

Modified designs and customized assemblies are available.

Applications of Permanent Magnet Power-Off Brakes

Our permanent magnet power-off brakes offer unique advantages that make them highly suitable for specific applications. For example:

  • Subsea Robotic Arms
  • Armatures for Surgical Robots
  • Mining Robotics

Contact the Experts at SEPAC Today

If you’re looking for electromagnetic brakes you can trust, turn to the experts at SEPAC. We’ve designed, engineered, and manufactured brake solutions for decades. This extensive experience enables us to deliver quality products for even the most specific or unique applications. To learn more about our permanent magnet brakes, check out this product page or submit a request for more information.


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