Modulating clutch having passive torque throughout threshold

摘要

A modulating clutch for disposition and use in a motor vehicle drive train includes a disc pack clutch assembly and clutch actuator. The clutch actuator includes an assembly for generating compressive force which is applied to the clutch pack assembly and a preload member which partially engages the clutch pack to provide torque transfer up to a predetermined level without activation of the clutch actuator. Activation of the clutch actuator increases the torque transfer or throughput above the predetermined level. The differential of the present invention thus functions passively as a limited slip differential by allowing torques in excess of the predetermined torque level to slip each axle relative to the driveline input thereby provide a constant, minimum level torque coupling between the driveline and each axle. When the clutch actuator is energized, it may be utilized to control torque transfer at levels above the predetermined level between the input and output of the clutch mechanism. The modulating clutch of the present invention has application in vehicle differentials.