Multi-Level Torque Clutch

摘要

A clutch assembly is disclosed having a clutch housing and a shaft. A clutch pack selectively couples rotation of the clutch housing and the shaft. The clutch pack includes a primary backing plate, a reaction plate, first and second friction plates disposed between the backing plate and the reaction plate, and a secondary backing plate disposed between the first and second friction plates. A first actuator selectively applies pressure to the reaction plate to move the reaction plate toward the primary backing plate. A second actuator controls movement of the secondary backing plate to switch the clutch pack between a low torque state and a high torque state. In the low torque state, the secondary backing plate cannot move longitudinally toward the primary backing plate beyond a locked position. In the high torque state, the secondary backing plate can move beyond the locked position.

主权项

1. A multi-level torque clutch assembly comprising:
a clutch housing having an internal surface that defines an inner cavity within said clutch housing; a shaft disposed within said inner cavity of said clutch housing, said shaft extending along a longitudinal axis and having an outer surface; a clutch pack disposed radially between said clutch housing and said shaft that selectively couples rotation of said clutch housing and said shaft; said clutch pack including a first end and a second end opposite said first end that is longitudinally spaced from said first end; a first actuator that selectively applies pressure to said first end of said clutch pack to force said first end toward said second end and longitudinally compress said clutch pack; said clutch pack including a primary backing plate disposed at said second end of said clutch pack, wherein said primary backing plate is retained on one of said clutch housing and said shaft such that said primary backing plate cannot move longitudinally relative to said clutch housing and said shaft beyond a predetermined limit; said clutch pack including a reaction plate disposed at said first end of said clutch pack that operably receives pressure from said first actuator and that is moveable along said longitudinal axis relative to said clutch housing and said shaft; said clutch pack including a first friction plate and a second friction plate disposed adjacent one another and between said primary backing plate and said reaction plate, said first and second friction plates being moveable along said longitudinal axis relative to said clutch housing and said shaft; said clutch pack including a secondary backing plate disposed between said first and second friction plates; and a second actuator controlling movement of said secondary backing plate to selectively switch said clutch pack between a low torque state and a high torque state, wherein said second actuator prevents said secondary backing plate from moving longitudinally toward said primary backing plate beyond a locked position when said clutch pack is in said low torque state, and wherein said second actuator permits longitudinal movement of said secondary backing plate toward said primary backing plate beyond said locked position when said clutch pack is in said high torque state.