| 摘要 |
<p>HYDRAULIC CONTROL SYSTEM A hydraulic control system is provided including a fluid reservoir, a variable displacement pump having a fluid input in fluid communication with the reservoir and having a fluid output, and a fluid actuated displacement control mechanism for controlling the displacement of the pump. A control valve is placed in fluid communication with the fluid output of the variable displacement pump and with the reservoir and is adapted to control the flow of fluid to a fluid actuated device. The control valve includes means for developing a control pressure signal. A sensor valve is placed in fluid communication with the control pressure signal, the displacement control mechanism, and the reservoir for placing the control pressure signal in fluid communication with the displacement control mechanism or for placing the displacement control mechanism in fluid communication with the reservoir, in response to the magnitude of the pressure control signal, thereby controlling the displacement of the pump in response to the magnitude of the pressure control signal. The control valve includes a plurality of plungers for controlling the flow of fluid between a central passageway, a supply manifold, service ports, and an exhaust manifold. Each of the plungers includes a plurality of metering notches for providing the only continuous flow path through the central passageway between the inlet and the exhaust port when the plungers are between a neutral position and an operating position. The fluid actuated displacement control mechanism is mechanically connected to the pump for controlling its displacement. The mechanism is provided with a fluid passage for placing the mechanism in fluid communication with the pump drain. The fluid passage includes a flow restriction which varies in response to the position of the mechanism.</p> |
