摘要 |
A fluid power system includes a hydraulic machine. A pilot-controlled supply valve controls high-pressure fluid to the machine. The valve is coupled between the hydraulic machine and a high-pressure fluid source, and includes a control port for an actuation signal. The supply valve allows passage of fluid from the machine to the fluid source, but blocks passage of fluid from the fluid source to the machine while closed, or permits passage of fluid from the fluid source to the machine while open. The supply valve biases toward closed or open according to an actuation signal at the control port. A pressurization valve is also coupled between the hydraulic machine and the high-pressure fluid source. The pressurization valve blocks passage of fluid from the fluid source to the machine while in a first position, and allows a restricted passage of fluid between its input and output ports while in a second position, to allow pressure to equalize on either side of the supply valve before the supply valve opens. |