How Reell Wrap Spring Clutches Work
As electric current is passed through the stationary coil, lines of magnetic flux are generated and used to attract the control ring to the shoulder. This control ring is attached to the spring which wraps down onto a hub as the input is turned. Torque is transferred from the input, through the spring, to the output. After electric current is removed, the magnetic attraction is lost, causing the clutch to disengage as the spring unwraps.