| 摘要 |
<p>PROBLEM TO BE SOLVED: To drive and brake a hydraulic motor while maintaining constant tension only with one hydraulic pump by providing a selector valve connected to both ends of a main line provided with the hydraulic motor, a main return line and a hydraulic pump to feed oil from the hydraulic pump in an optional quantity to one optional end of the main line and to make excess oil flow to the main return line. SOLUTION: Oil is fed to a main line 1 including a hydraulic motor M, from a tank 4 through a feed line 3 by a hydraulic pump P connected to an engine 2 serving as a power source. Both end parts of the feed line 3 and main line 1 are connected to a selector valve 5. The selector valve 5 can feed oil fed from the hydraulic pump P through the feed line 3, in an optional quantity to one optional end of the main line 1. Excess oil is returned to the tank 4 from a return line 6. A pressure holding line 7 connected to the return line 6 is extended from the discharge side of the hydraulic motor M during normal rotation and provided with first and second check valves 8, 9.</p> |
