BigPatents India

An electromagnetic clutch assembly having a solenoid activated ball ramp operator provides reduced power consumption and improved control. The electromagnetic clutch assembly includes a primary or pilot friction clutch pack and a secondary or main friction clutch pack. An annular solenoid coil cooperates with an annular operator or plunger. When the coil is energized, the annular plunger translates and compresses the primary or pilot friction clutch pack. Activation of the pilot clutch pack retards motion of one of the members of the ball ramp operator which, in turn, compresses a secondary or main friction clutch pack disposed across the input and output members. (FIG.1).