Low noise hydraulic servo valve

摘要

A fluid flow control valve which includes a body formed to define a chamber having inlet, outlet and actuating ports for supplying and receiving fluid to and from external hydraulic machinery to be actuated and including a valve spool formed with several lands and slidably arranged in the chamber for controlling the flow of fluid through the ports, in which the lands and ports are located and arranged so that some of said ports transmit fluid only from said chamber outward while the remainder of the ports transmit fluid only from the ports into the chamber, and which also includes a matrix of restrictors interposed in each of those ports which transmits fluid outward from the chamber, and in which the lands are arranged to control the flow of fluid through only those ports which transmit fluid outward while leaving the flow of fluid into the chamber through the remaining ports unimpeded for all positions of the spool.