What is a Clutch

A clutch is a device that transmits power between two mechanisms (usually rotating) selectively. When the clutch is engaged, it ¡°slips¡± until the two mechanisms rotate at the same speed and the power is transmitted. When the clutch is disengaged, the two mechanisms are decoupled and allowed to rotate at different speeds. Power is not transmitted. Clutch is similar in principle to brake. In a brake, the driven mechanism would be connected to a fixed frame.

 

In a magnetic particle clutch, an energized coil applies magnetic flux to magnetic particles in a powder cavity causing them to bind together. The binding of the particles causes the driving (rotor) and driven (armature) components to experience drag which causes torque to be transmitted from one to the other via the particles. The strength of the binding (and accordingly, the deceleration torque generated) can be finely controlled by the varying the amount of current provided to the coil.