Patent ID: 6102178
Filing Date: 2000-08-15
Classification: B60K,F16D,F16H,Y10T

Abstract:
A center differential device of the type including an input shaft adapted to receive input torque, at a speed of rotation representative of the speed of rotation of a pair of primary drive wheels, an output shaft adapted to provide driving torque to a pair of secondary drive wheels, and a clutch pack including at least a first friction disc fixed to rotate with said input shaft, and at least a second friction disc fixed to rotate with said output shaft, and means operable to move said friction discs between a disengaged position and an engaged position; characterized by:(a) said means operable to move said friction discs comprises a cam ramp actuator including first and second ramp plates, and a plurality of cam members, each operably disposed between said first and second ramp plates, and in engagement with first and second ramp surfaces, respectively;(b) said second ramp plate being disposed axially adjacent said friction discs and being operable to move said friction discs toward said engaged position, said second ramp plate being fixed to rotate with said output shaft;(c) said means operable to move said friction discs further comprising a viscous coupling including an input coupling member fixed to rotate with said input shaft, and an output coupling member;(d) said output coupling member being fixed to rotate with said first ramp plate, whereby, any speed difference between said input and output shafts will result in a corresponding slip speed between said input and output coupling members, thus generating a viscous shear torque representative of said slip speed, said viscous shear torque being applied to said first ramp plate to displace said cam ramp actuator from a neutral position to a clutch actuating position; and(e) said viscous coupling including a housing member cooperating with one of said input and output coupling members to define a viscous shear chamber, said output coupling member being disposed in said viscous shear chamber and including a shaft portion extending axially through said housing member and being in rotational engagement with said first ramp plate.