| 摘要 |
PURPOSE:To reduce a power loss by controlling a passage switching means, in order, according to an oil consumption amount of a hydraulic device. CONSTITUTION:First and second pump mechanisms P1 and P2 are provided and the delivery passages 1a and 1b of the pump mechanisms P1 and P2, respectively, are branched into passages 2a and 2b on the output side and passages 3a and 3b on the reflux side. A switching valve 18 by which a flow passage is switched in response to a pressure in an output line 5 is located in the passages 2a and 2b on the reflux side. Since a difference between a delivery flow rate of working oil to the output line 5 and an oil consumption amount of a hydraulic device G is produced as the fluctuation in a pressure of the output line 5, a delivery flow rate of working oil is controlled, in order, by means of the switching valve 18 operated in response to a pressure in the output line. |
