Pulley with asymmetric torque-sensitive clutching

摘要

A pulley assembly for an automobile accessory drive system includes a shaft engaging hub, a nut threaded onto the shaft engaging hub, an annular bushing, and one or more brake shoes positioned around the outside of the annular bushing all housed with a pulley member. The nut is capable of axial translation relative to the annular bushing and the annular bushing is capable of expanding radially outward in response to the axial translation of the nut in a first direction to provide frictional engagement between the inner coupling surface of the pulley member and the outer coupling surface of the brake shoes, which transfers torque from the pulley member to the input shaft. The nut includes a generally frustoconical outer surface, opposite its inner threaded surface, for seating the nut in the annular bushing.

主权项

1. A pulley assembly for use in an automobile accessory drive system, the pulley assembly comprising:
a shaft engaging hub including an axis of rotation, an outer threaded surface, and a bore for receiving an accessory input shaft for engagement therewith;
a pulley member including a bore that receives the shaft engaging hub, the pulley member including an inner coupling surface and an outer peripheral belt-engaging surface;a nut including an inner threaded surface that is engaged with the outer threaded surface of the shaft engaging hub, the nut having a generally frustoconical outer surface opposite the inner threaded surface;an annular bushing having the nut seated therein for rotation therewith; and one or more brake shoes positioned around an outside of the annular bushing, the brake shoes having an outer coupling surface in frictional contact with the inner coupling surface of the pulley member; wherein the nut is capable of axial translation relative to the annular bushing and the annular bushing is capable of expanding radially outward in response to the axial translation of the nut in a first direction.