Abstract: The present invention relates to a clutch assembly for selectively coupling a supercharging blower or other driven device to a mechanical output of a prime mover, such as a diesel engine. The clutch assembly includes an input member which is preferably flexibly coupled to a rotatable blower drive gear member connected to the engine. The input member is journalled about a centrally disposed hub. An output shaft is secured to the hub and carries power to the driven device. The input member includes a plurality of longitudinally oriented slots which receive radially extending lugs formed on a first plurality of disc pack clutch plates. A second plurality of clutch plates or separators is interleaved with the first plurality of clutch plates to form a friction disc pack clutch. The second plurality of clutch plates includes centrally disposed splines which engage complementarily sized splines formed on the hub. A radially extending piston plate is formed integral with the hub.

Abstract: A torque limiting mechanism provides for a spring loaded coupling of driver and driven friction discs for simultaneous and uniform rotation. A spring retainer system is incorporated which provides restraint against expansion of the spring beyond a predetermined limit. In a preferred embodiment the spring becomes inoperative to urge the discs together after friction linings on the discs have worn to a predetermined design limit. A condition of zero torque is thereby created, thus signalling need for replacement of friction linings.