Patent ID: 6287232
Filing Date: 2001-09-11
Classification: F16H

Abstract:
A non-finite speed ratio transmission device for use with a vehicle, comprising:a toroidal continuously variable transmission which varies a speed ratio according to a gyration angle of a power roller gripped by an input disk and output disk, the power roller varying the gyration angle according to a displacement of a supporting member which supports the power roller;a fixed speed ratio transmission which varies a rotation speed of the input disk at a fixed speed ratio;a planetary gear unit having a final output shaft which varies a rotation direction according to a relation between a rotation output speed of the toroidal continuously variable transmission and a rotation output speed of the fixed speed ratio transmission;a hydraulic cylinder comprising a first oil chamber and second oil chamber, which displaces the supporting member according to a differential pressure between the first oil chamber and the second oil chamber;a direction change-over valve which comprises a valve body, a pressure port selectively connected to one of the first oil chamber and second oil chamber, according to whether the speed ratio of the toroidal continuously variable transmission should be increased or decreased, based on the displacement of the valve body, a first drain port connected to the first oil chamber when the pressure port is connected to the second oil chamber, and a second drain port connected to the second oil chamber when the pressure port is connected to the first oil chamber;an actuator which displaces the valve body;a feedback member which connects the supporting member and direction change-over valve, and feeds back a displacement of the power roller to the direction change-over valve, the valve body being displaced by the feedback member in a direction opposite to a direction of displacement of the valve body due to the actuator;a first oil pressure control valve which is connected to the first drain port of the direction change-over valve and varies a pressure of the first drain port between zero and the pressure of the pressure port; anda second oil pressure control valve which is connected to the second drain port of the direction change-over valve and varies a pressure of the second drain port between zero and the pressure of the pressure port.