Operation of an Electric Clutch

Energizing the electric clutch  field coil with DC power creates a powerful electromagnet.  The armature plate is pulled onto the rotor with considerable force.  This closes the airgap and connects the pulley to the shaft.  The round spring allows the armature to move back and forth depending on whether the clutch is engaged or disengaged.  It also transmits torque from pulley to shaft or shaft to pulley in either direction (clockwise or counterclockwise) with no backlash.