SWITCHABLE WATER PUMP WITH DUAL FRICTION PLATE ACTUATION

摘要

An electromagnetic clutch includes a rotatable input member or pulley and a rotatable output member or shaft. A hub cover is coupled to the pulley and includes an inner facing surface located proximal an outer friction pad or clutch plate which is fixed for rotation with the output member. An armature plate is axially moveable relative to the output member and is biased toward a position of engaging the clutch plate and the hub cover for transferring a torque from the pulley to the output shaft. A self-energizing actuator converts rotary motion of the input member or pulley to linear movement of the armature plate to further engage the clutch. The actuator includes a biasing member urging relative rotation between the one of the input member and the output member and the armature plate to initially engage the armature plate and the clutch plate. An electromagnet is provided for axially translating the armature plate away from the friction plate to disengage the clutch plate from the hub cover thereby disengaging the input force from the pulley. The clutch plate is coupled to the shaft using a splined coupling which does not prevent axial movement of the clutch plate on the shaft.