Patent ID: 6764421
Filing Date: 2004-07-20
Classification: F16H

Abstract:
A pulley pressure control system for a transmission comprising a variable pitch primary pulley used as an input pulley or an output pulley including movable and fixed disks or two movable disks applied a pressing force or an elastic force generated to be variably press-controlled by a compressing device, and an endless belt movably held between said two disks, said pulley pressure control system comprising:a pressure application device for applying at least one of a pressing force and an elastic force to said movable disk, in which the pressing force applied to said movable disk regulates a speed ratio of said transmission by shifting a position of said endless belt on said pulley and the elastic force applied to said movable disk regulates torque using a frictional force; a pressing force supply path having one of pressing ends caused by both primary and secondary compressing devices responsive to two instructions and variable press-controlling directly said movable disk; an elastic force supply path having the other of said pressing ends caused by said primary and secondary pressing devices and variably press-controlling said movable disk indirectly through an elastic device compressed in series by said other pressing end; two driving sources, individually connected to said primary and secondary pressing devices, for driving one or both of said pressing force supply path and said elastic force supply path responsive to said instructions; and a control device for providing an instruction for each driving source and selecting the pressing force or the elastic force and regulating values of the pressing force or the elastic force.