Bi-Directional Overrunning Clutch With Improved Indexing Mechanism

A bi-directional overrunning clutch assembly for engaging secondary driven shafts in a four wheel drive vehicle, the assembly comprising:

• a differential housing including a differential case and a cover removably mounted to the case;
• a pinion input gear rotatably disposed within case and including a shaft extending out from the case and adapted to engage a drive shaft, the pinion input gear rotatable within the case;
• a ring gear located within the differential case and engaged with the pinion input gear such that rotation of the pinion input gear produces rotation of the ring gear;
• a bi-directional overrunning clutch housing formed on or attached to the ring gear such that rotation of the ring gear produces corresponding rotation of the clutch housing, the clutch housing having an internal diameter with a contoured surface, the clutch housing having a clutch pin extending outward from one side of the clutch housing;
• a pair of hubs substantially coaxially aligned with each other and located within the clutch housing, each hub adapted to engage an end of a secondary driven shaft;
• a roll cage assembly located within the clutch housing and including a roll cage with two sets of rolls, each roll disposed within a slot formed in the roll cage, the rolls spaced around the circumference of the cage, and a plurality of springs for positioning the rolls in the slots, wherein one set of rolls is located between a portion of the contoured surface of the clutch housing and an outer surface of one hub, and the other set of rolls is located between a portion of the contoured surface of the clutch housing and an outer surface of the other hub;
• an electromagnetic system for indexing the roll cage relative to the clutch housing, the electromagnetic system including first and second indexing devices for indexing the roll cage, and an electronic control system connected to each indexing device for activating the indexing devices,
• the first indexing device configured when activated to cause the roll cage to index in a first direction relative to the clutch housing so as to index the roll cage into an active drive state where the rolls are positioned to cause the secondary drive shaft to be coupled to the secondary driven axles when four wheel drive is needed, the first indexing device including an electronically controlled drive assembly attached to the differential housing at a location radially outward from one of the hubs, and a first armature plate disposed about the hub and adjacent to the electronically controlled drive assembly, the armature plate engaged with the roll cage;
• and
• the second indexing device configured when activated to cause the roll cage to advance in a second direction relative to the clutch housing that is opposite from the first direction so as to cause the roll cage to index into an active backdrive state where the rolls are positioned to cause the secondary driven shafts to be coupled to the secondary drive shaft for providing torque transfer from the secondary driven shafts to the secondary drive shaft during an engine braking condition;
• the second indexing device including an electronically controlled backdrive assembly attached to the differential at a location radially outward from one of the hubs, a second armature plate disposed about the same hub as the electronically controlled backdrive assembly and adjacent to the electronically controlled backdrive assembly, the second armature plate engaged with the roll cage, and a hub plate positioned between the electronically controlled backdrive assembly and the second armature plate, the hub plate engaged with the same hub as the electronically controlled backdrive assembly so as to rotate in combination with that hub, the electronically controlled backdrive assembly being electrically connected to the electronic control system.