Patent ID: 7217215

Claim:
A power transfer assembly comprising: a plurality of balls distributed radially about a longitudinal axis of the power transfer assembly, each ball having a tiltable axis about which it rotates; an input disc in contact with the balls; an output disc in contact with the balls; an idler coaxial and rotatable about the longitudinal axis and in contact with the balls; a bearing disc mounted along the longitudinal axis and operationally coupled to the input disc; a fluid pressure drive device adapted to vary the contact force between the bearing disc and the input disc; a limiting member configured to limiting the axial displacement of the bearing disc; wherein the limiting member produces an elastic resistance against a direction of the displacement when there is no fluid pressure from the pressure drive device and the bearing disc receives an input torque; and an axial force generator adapted to generate a contact force between the input disc, the output disc, the balls and the idler, wherein the axial force generator comprises: a thrust washer coaxial with the idler, the washer having a first side facing the input disc and having a set of thrust ramps formed on the first side; a set of thrust-receiving ramps formed on the input disc facing the thrust washer; and a plurality of thrust elements in contact with the thrust ramps and the thrust-receiving ramps.