Hydraulic servovalve

摘要

A hydraulic servovalve controls the direction of flow of a working fluid and a flow rate of a working fluid between a plurality of ports. The hydraulic servovalve includes a spool axially movably disposed in a valve body for changing a direction of a working fluid and varying a flow rate of the working fluid, a sleeve disposed in the valve body and having a spool hole for housing the spool, a pair of hydrostatic bearings disposed in the sleeve around respective opposite end portions of the spool, and a plurality of windows defined in the sleeve as control orifices for controlling a flow rate of a working fluid. The hydraulic servovalve further includes a fluid passageway communicating between the supply port and the control port through one of the windows, and a fluid passageway communicating between the control port and the return port through the other of the windows.