Magnetic Hysteresis Brakes

Precise, permanent, worry-free tension control for fibre-optic cable, light gauge wire, and a variety of power transmission applications.

Magnetic hysteresis brakes use permanent magnets surrounding a hysteresis disc to provide a constant torque, without external power. By varying the displacement of the magnetic hysteresis disk, this torque can be quickly adjusted by a machine operator. The magnetic brakes are ideally suited to control winding applications in the wire, cable and converting industries and anywhere a constant torque is required. There is no magnetic particle leak (the magnetic field is fully contained within the device). As the braking force is created by non-contact means (magnetic field instead of friction) the device is subject to minimum wear and is almost maintenance free. The devices can also be used in custom form as magnetic drive couplings for environmentally sealed units or as a torque limiter on a rotating drive system.


Why use Magnetic Hysteresis Brakes?
- Constant torque independent of shaft (rotor) speed
- No break-away torque
- No contacting or wearing parts
- No friction elements - same smooth torque year after year
- No magnetic particles to leak or contaminate end product
- Operable in some of the most difficult wet environments
- No external electricity to operate
- Brake (with shaft) and clutch (with hollow shaft) available
- Custom designs are also available.


How they operate
All important internal clearances are ground to tolerances of less than .025mm (.001 inch). Magnet assemblies (purple) surround our hysteresis assembly (gold). When like poles face each other, they produce maximum magnetic saturation of the hysteresis disc, forcing lines of flux to travel circumferentially through the hysteresis disc. This produces maximum torque.

When opposite poles face each other, they produce minimum saturation of the hysteresis disc. The lines of flux travel right through the hysteresis disc.
Combinations of adjustment angles between these two extremes gives infinite adjustability. Because there are no contacting surfaces, the setting can be maintained indefinitely.

Torque (Nm) :  0.001 to 0.014
Bending moment (Nm) :  0.22 
Heat dissipation (watts) :  2.2 
Max. RPM at max. torque :  1500

Torque (Nm) :  0.003 to 0.014
Bending moment (Nm) :  1 
Heat dissipation (watts) :  13
Max. RPM at max. torque :  900

Torque (Nm) :  0.03 to 1.36
Bending moment (Nm) :  n/a 
Heat dissipation (watts) :  n/a 
Max. RPM at max. torque :  200

Torque (Nm) :  0.003 to 0.014
Bending moment (Nm) :  4 
Heat dissipation (watts) :  13 
Max. RPM at max. torque :  900

Torque (Nm) :  0.11 to 2.8
Bending moment (Nm) :  225 
Heat dissipation (watts) :  150 
Max. RPM at max. torque :  200

Torque (Nm) :  0.42 to 7.9
Bending moment (Nm) :  225 
Heat dissipation (watts) :  150 
Max. RPM at max. torque :  180

Torque (Nm) :  0.035 to 0.62
Bending moment (Nm) :  12 
Heat dissipation (watts) :  18 
Max. RPM at max. torque :  450

Torque (Nm) :  0.14 to 4.5
Bending moment (Nm) :  17 
Heat dissipation (watts) :  95 
Max. RPM at max. torque :  180

Torque (Nm) :  0.014 to 0.56
Bending moment (Nm) :  5 
Heat dissipation (watts) :  18 
Max. RPM at max. torque :  450

Torque (Nm) :  0.33 to 7.9
Bending moment (Nm) :  23 
Heat dissipation (watts) :  150 
Max. RPM at max. torque :  180

Torque (Nm) :  0.33 to 7.9
Bending moment (Nm) :  23 
Heat dissipation (watts) :  150 
Max. RPM at max. torque :  180

Torque (Nm) :  0.015 to 1.46
Bending moment (Nm) :  225 
Heat dissipation (watts) :  28 
Max. RPM at max. torque :  180

Torque (Nm) :  0.68 to 15
Bending moment (Nm) :  23 
Heat dissipation (watts) :  180 
Max. RPM at max. torque :  180

Also Available...

Assemblies for Constant Tension and Accessories
Machinery Products Index
Magnetic Hysteresis Brakes Part Numbers