| 摘要 |
<p>PURPOSE:A means is provided to obtain a required revolving power greater than a specified value regardless of load on the arm, when rotating hydraulic motor and arm hydraulic cylinder are simutatneously operated. CONSTITUTION:When the load of the hydraulic arm cylinder 40 is less than that of the rotating hydraulic motor 50, oil pressure of pump 2 actuates the cylinder 40 to generated differential pressure at both sides of throttle E and switch valve 32a works. And when the cylinder 40 extends to cause the arm excavation, the switch valve 32a moves to the right, actuating throttle F. Then, the pump 32a increases its discharge pressure to the value corresponding to the resistance of the throttle F. Therefore, if the resistance of the throttle F is set to the value exceeding the motor 50 starting load, the pressure oil of the pump 3a is fed to the motor 50 to actuate it.</p> |
