| 摘要 |
A hydraulic system comprised of a pump (10), a first valve (15) in the inlet (11) to the pump (10), and a second valve (18) which activates or deactivates a third valve (20) which permits the loading and unloading of the pump discharge. A motor (16) is provided to operate the first valve (15) for opening or closing the pump inlet (11). This motor (16) also actuates the second valve (18) in concert with the operation of the first valve (15) to open or close a vent port to the third valve (20) which opens or closes the passage (19) from the pump discharge to tank, located away from the pump inlet (11). This permits unloading the pump discharge during the restriction (23) of the pump inlet (11) and allows the loading of the pump discharge after the opening of the pump inlet (11). With the pump inlet (11) restricted (23), the system provides a low restrictive passage (23) for circulating the prescribed small volume of flow used to lubricate and cool the pump. |
