Clutch valve system for static hydraulic continuously variable transmission

摘要

A clutch valve system for use in a static hydraulic continuously variable transmission in which a hydraulic closed circuit is formed between a swashplate type hydraulic pump and a swashplate type hydraulic motor, wherein a first annular oil chamber and a second annular oil chamber are concentrically defined in the pump cylinder adjacent to annularly arranged cylinder bores of a pump cylinder in the hydraulic pump, the first oil chamber being adapted to be connected to the cylinder bores which are in a discharge stroke and the second oil chamber being adapted to be connected to the cylinder bores which are in a suction stroke; a plurality of clutch valves are radially arranged in the pump cylinder for providing the communication or discommunication between both the oil chambers by the radial movement thereof; and a clutch control ring engaged with the clutch valves for relative rotation therebetween so as to surround these clutch valves is pivoted on a fixing structure for pivotal movement between a clutch ON position in which it brings all the clutch valves into a closed state in the diametrical direction of the pump cylinder and a clutch OFF position in which it brings some of the clutch valves into an opened state.