Patent ID: 6725990
Filing Date: 2004-04-27
Classification: F16D

Abstract:
A power transmission device comprising:an input member adapted to receive drive torque from a source of torque; an output member adapted to provide drive torque to an output device; a torque transfer mechanism operable for transferring drive torque from said input member to said output member; said torque transfer mechanism including: a friction clutch assembly operably disposed between said input member and said output member; a ball screw operator having a first screw member mounted on said output member and a second screw member supported for axial movement relative to said first screw member for generating a clutch engagement force to be applied to said friction clutch assembly; a resilient coupling mechanism for coupling said first screw member for rotation with said output member; and a magnetorheological actuator having a rotor with a first portion fixed for rotation with said first screw member and a second portion disposed in a chamber filled with a magnetorheological fluid, and a electromagnetic coil arranged to vary the viscosity of said fluid in said chamber in response to electric control signals; and a controller for generating said electric control signals.