Blog

How does an electromagnetic brake work?

How does a brake on a motor work?

Power off brakes stop or hold a load when electrical power is either accidentally lost or intentionally disconnected. In the past, some companies have referred to these as "fail safe" brakes. These brakes are typically used on or near an electric motor. Typical applications include robotics, holding brakes for Z axis ball screws and servo motor brakes. Brakes are available in multiple voltages and can have either standard backlash or zero backlash hubs. Multiple disks can also be used to increase brake torque, without increasing brake diameter. There are 2 main types of holding brakes. The first is spring applied brakes. The second is permanent magnet brakes.

Spring type - When no electricity is applied to the brake, a spring pushes against a pressure plate, squeezing the friction disk between the inner pressure plate and the outer cover plate. This frictional clamping force is transferred to the hub, which is mounted to a shaft.

Permanent magnet type – A permanent magnet holding brake looks very similar to a standard power applied electromagnetic brake. Instead of squeezing a friction disk, via springs, it uses permanent magnets to attract a single face armature. When the brake is engaged, the permanent magnets create magnetic lines of flux, which can in turn attract the armature to the brake housing. To disengage the brake, power is applied to the coil which sets up an alternate magnetic field that cancels out the magnetic flux of the permanent magnets.

Both power off brakes are considered to be engaged when no power is applied to them. They are typically required to hold or to stop alone in the event of a loss of power or when power is not available in a machine circuit. Permanent magnet brakes have a very high torque for their size, but also require a constant current control to offset the permanent magnetic field. Spring applied brakes do not require a constant current control, they can use a simple rectifier, but are larger in diameter or would need stacked friction disks to increase the torque.


0 Comments
Leave a Comment
Your email address will not be published. Required fields are marked *
Submit Comment
Concact Us Now
Gear Motor Manufacturer,Planet Gearbox Manufacturer,Planet Gear Motor Manufacturer,automotive motor Manufacturer-Ningbo Twirl Motor Co.,Ltd
NO.1269 Mingshu Road,Jiangshan Industrial Zone, Yinzhou District, NingboZhejiang Province China
You can trust us
We are a professional Manufacturer in China, and we are constantly innovating so that our customers can have better products and services.
© 2018 Gobalsir Inc.    RELATED ARTICLES        SiteMap.html    SiteMap.xml
Marketing Support by Globalsir
Enter your inquiry details, We will reply you in 24 hours.
Name can't be empty
E-mail can't be empty
Company can't be empty
Phone can't be empty
Products can't be empty
Message can't be empty
Verification code error
code
Refill