| 摘要 |
PURPOSE:To make a hydraulic motor lockable at the desired position, by forming a closed circuit with those elements, such as a variable delivery pump, a hydraulic motor and a counterbalance valve, and installing a selector valve in addition, while imparting a braking force to the hydraulic motor with a variable delivery pump employed. CONSTITUTION:A closed circuit is formed of a variable delivery pump 2, a hydraulic motor 6 and a counterbalance valve 4 in combination, and a pilot chamber 15 of the valve 4 and a discharge port 2a of the pump 2 are coupled together via a pilot selector valve 41. Likewise, the selector valve 41 is interconnected to an inflow port 6a of the hydraulic motor 6 whereby the pilot chamber 15 of the counterbalance valve 4 is made so selectably at will to either a tank 42 or the discharge port 2a. And, when the pilot chamber 15 is opened to the tank 42, both inflow and outflow ports 6a and 6b of the hydraulic motor 6 are closed as well as when the pilot chamber 15 is interconnected to the discharge port 2a, this discharge port 2a of the pump 2 and the inflow port 6a of the hydraulic motor 6 are interconnected each other. |
