Dual clutch rear axle and method of operation

An adaptive torque delivery system for a primary front wheel drive vehicle comprising, in combination,

• a primary drive line disposed forward in such vehicle and having a differential, a pair of axles and a pair of primary tire and wheel assemblies,
• a secondary drive line disposed rearward in such vehicle and having a twin clutch differential, a pair of secondary axles and a pair of secondary tire and wheel assemblies,
• said twin clutch differential including an input member, a gear set driven by said input member and driving an output member, a pair of clutches operably disposed between said output member and a respective one of said secondary axles, each of said clutches disposed upon a reaction force member having two spaced-apart stops and including a multiple disc clutch assembly and a clutch operator disposed between said two spaced-apart stops,
• a wheel speed sensor having an output associated with each of said primary and said secondary tire and wheel assemblies, and
• a microprocessor having a plurality of inputs for said speed sensor outputs and a pair of outputs driving a respective one of said clutch operators of said pair of clutches.

A method of operating a dual clutch axle in a secondary drive line of a motor vehicle having primary front wheel drive comprising the steps of:

• independently sensing a speed of four tire and wheel assemblies of such motor vehicle,
• sensing a speed of one of primary and secondary prop shafts,
• converting such sensed speeds into electrical signals,
• providing such signals to individual inputs of a microprocessor,
• providing a transaxle having a primary output driving a primary differential and primary tire and wheel assemblies and a secondary output,
• providing a twin clutch rear axle having a bevel gear set driven by said secondary output and driving both clutches of said twin clutch rear axle,
• providing independent electrical signals from said microprocessor to each of said clutches of said twin clutch rear axle to engage said clutches and deliver torque to a respective one of a pair of rear axles and secondary tire and wheel assemblies to control yaw in said motor vehicle.

A clutch for use in a motor vehicle drive line component comprising, in combination,

• an input
• an output member having a pair of spaced-apart stops,
• a modulating clutch assembly disposed on said output member between said pair of spaced-apart stops, said modulating clutch having a first plurality of clutch discs disposed for rotation with said input, a second plurality of clutch discs interleaved with said first plurality of clutch discs and disposed for rotation with said output member and a clutch operator for compressing said first and said second pluralities of clutch discs,
• said clutch operator including a stationary electromagnetic coil, a rotor partially surrounding said electromagnetic coil, a band of magnetic flux directing material disposed about said rotor and an armature disposed adjacent said rotor, and
• a ball ramp operator having a pair of opposed circular members defining complementarily configured opposed ramped recesses and rolling members disposed in said recesses whereby relative rotation of said members translate said members axially, whereby reaction force generated during clutch operation is contained in said output member.