Continuously variable traction roller transmission

Claim 1

A continuously variable traction roller transmission comprising: a casing; input and output toroidal discs arranged in said casing to face each other; a pair of traction rollers each being disposed between and in engagement with said input and output discs; roller supporting members respectively supporting said traction rollers through respective eccentrical shafts, each roller supporting member being so arranged that when moved axially, the member is rotated about its axis while pivoting the corresponding traction roller; hydraulic actuators for axially moving the respective roller supporting members; a process cam connected to one of said roller supporting members to move therewith; a speed change instruction means; a speed change control valve including a first member which is axially moved by said speed change instruction means and a second member which is movable coaxially relative to said first member, said control valve feeding said hydraulic actuators with hydraulic pressure whose magnitude depends on the relative displacement between said first and second members; a L-shaped pivotal link having one end pivotally connected to said second member and the other end operatively contacting with a cam surface of said process cam; and means defined by said cam surface of the process cam, said means increasing a rate of axial movement of the second member to a rotational movement of the roller supporting member when said traction rollers are in a condition for reducing the speed change ratio between said input and output discs but decreasing said rate when said traction rollers are in a condition for increasing the speed change ratio.