| 摘要 |
PURPOSE:To reduce the size of a device, by a method wherein, in a fluid transmission in which the discharge amount of a pump is controlled to be kept at a constant value by means of a constant speed unit, the unit is switchable into a lock or a free state by means of a cam in linkage with control of a discharge control value unit. CONSTITUTION:A variable volume pump, operated by a prime mover, and an actuator are interconnected through a pair of circuit to form a closed circuit, a discharge circuit 14 of a discharge pump 3 for supplying pressure oil is connected to said closed circuit, and a discharge amount control valve unit A and a constant speed valve unit B are located in the discharge circuit 14. The unit B detects the discharge amount of a variable volume pump as a differential pressure between parts before and behind an orifice 8 in a circuit 5, and a valve 42 is actuated according to the differential pressure. A cam 55, being capable of shifting the valve 42 to a lock position or a free position, is positioned to an engaging part 57 located to the intermediate part of the valve 42, and the cam 55 is operated in linkage with a control handle 12 of the unit A. |
