| 摘要 |
<p>An infinitely variable belt-drive transmission for an engine comprises a primary pulley (24) having a hydraulically shiftable disc (24a), a secondary pulley (28) having a hydraulically shiftable disc (25a), a belt (26) engaged with both pulleys, and a hydraulic circuit having a pump (37) for supplying oil. The transmission has a control system which includes a transmission ratio control valve (44) responsive to engine speed for controlling the oil supply and for shifting the disc (25a) of the primary pulley (24) to change the transmission ratio, and a pressure regulator valve (43) which responds to the transmission ratio and controls the line pressure in the hydraulic circuit. A piston (62) is slidably mounted in the hydraulic cylinder (27b) of the primary pulley (24) and a valve (61) having a solenoid (67) controls the application of line pressure to the hydraulic cylinder to shift the piston (62) so as to restrict the movement of the disc in the direction towards the maximum transmission ratio position.</p> |
