Clutch with Decremental Torque Function

A 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 backing plate retained on one of said clutch housing and said shaft such that said backing plate cannot move longitudinally relative to said clutch housing and said shaft beyond a predetermined limit;
• said clutch pack including an applied plate slidably retained on one of said clutch housing and said shaft such that said applied plate is moveable along said longitudinal axis relative to said clutch housing and said shaft;
• said clutch pack including a plurality of friction plates disposed between said backing plate and said applied plate, said plurality of friction plates being slidably retained on one of said clutch housing and said shaft such that each friction plate of said plurality of friction plates is moveable along said longitudinal axis relative to said clutch housing and said shaft;
• said clutch pack including a plurality of reaction plates disposed between said backing plate and said applied plate in an interleaving relationship with said plurality of friction plates, said plurality of reaction plates being slidably retained on one of said clutch housing and said shaft such that each reaction plate of said plurality of reaction plates is moveable along said longitudinal axis relative to said clutch housing and said shaft;
• a primary actuator that selectively applies pressure to said applied plate to move said applied plate toward said backing plate in order to longitudinally compress said clutch pack and couple rotation of said clutch housing and said shaft;
• a first set of secondary actuators that selectively applies pressure to a first reaction plate of said plurality of reaction plates to longitudinally move said first reaction plate independently of said applied plate;
• and
• a second set of secondary actuators that selectively applies pressure to a second reaction plate of said plurality of reaction plates to longitudinally move said second reaction plate independently of said applied plate and independently of said first reaction plate.

A method of engaging a clutch assembly having a shaft, a clutch housing, and a clutch pack including a backing plate, an applied plate, and a plurality of friction plates and reaction plates disposed between the backing plate and the applied plate in an interleaving relationship, the method comprising the steps of:

• applying torque to the shaft;
• preventing the backing plate from traveling longitudinally beyond a predetermined limit measured relative to the shaft and the clutch housing;
• applying pressure to at least one plate in the plurality of friction plates and reaction plates to move the at least one plate longitudinally toward the backing plate in order to compress a portion of the clutch pack disposed between the at least one plate and the backing plate;
• and
• applying pressure to the applied plate to move the applied plate longitudinally toward the backing plate in order to compress the plurality of friction plates and reaction plates disposed between the applied plate and the backing plate to transfer torque from the shaft to the clutch housing via the clutch pack.