| 摘要 |
An improved hydraulic valve assembly comprising a directional valve, such as a spool valve, and a pilot valve of a unique design. The pilot valve comprises a rocker arm, which is controlled by motor means imparting a torque on the rocker arm so as to move a pair of flappers toward and away from associated nozzles controlling pilot pressure to opposite ends of the directional valve. When one of a pair of transducers senses the pressure of hydraulic fluid returning from the directional valve, an opposing torque is imparted to the rocker arm. Equilibrium is achieved when the torques balance each other. The nozzles are provided with annular buffers preventing the nozzles and the flappers from being pressed against each other. The directional valve employs flow restrictors of a unique design wherein annular plates, in a stack, are provided with integral, arcuate, spaced baffles. The baffles, which are equal in angular width, are interdigited so as to provide serpentine paths for hydraulic fluid flowing radially through such restrictors. |
