| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a hydraulic driving gear decreasing a back pressure by eliminating a check valve to provide a circuit directly returned to a tank. SOLUTION: Supply oil routes 4A, 4B having oil hydraulic pumps 3A, 3B and discharge oil routes 5A, 5B are respectively provided corresponding to a pair of tanks 2A, 2B. The supply oil routes 4A, 4B and the discharge oil routes 5A, 5B are connected to a hydraulic operating parts 6A, 6B. A solenoid valves 7A, 7B are interposed in the discharge oil routes 5A, 5B, a branch routes 8A, 8B from the solenoid valves are connected to the tanks 2A, 2B in an opposite side. The tank is provided with respectively an upper level sensor 9A, 9B and a lower level sensor 10A, 10B. The solenoid valve is turned on by detecting operation of the upper level sensor, the discharge oil route is connected to the branch route. The solenoid valve is turned off by detecting operation of the lower level sensor, the branch route is interrupted.</p> |
