| 摘要 |
<p>PURPOSE:To accomplish speeding up in a single travelling operation, smooth and accurate actions individually in a simultaneous slewing and travelling operation and to obtain higher efficiency for each working at modes of operations other than travelling. CONSTITUTION:Fixed delivery pumps of equal capacity 1-4 are employed. In a single travelling operation, alone, the fluids discharged from the first and second pumps 1 and 2 flow together to the travelling motor 84 and those from the third and fourth pumps 3 and 4 flow together to the travelling motor 85 separately to increase the travelling speed. In the simultaneous slewing and travelling operation, the fluid from the fourth pump 4 flows to the tank 18 while the fluids from the first, the second and the third pumps 1-3 are fed to the slewing motor 81 and right and left travelling motors 84 and 85 independently. In the other modes of operations, the fluids discharged from four pumps 1-4 are effectively utilized to speed up the actuator in the low pressure range while in the high pressure range, with the unloading of the fourth pump, the fluids discharged from the other three pumps are adequately utilized.</p> |
