Patent ID: 8640723

Claim:
A pilot valve configured to provide a control pressure to a subsequent valving component within a dynamic fluid system, said pilot valve comprising: a valve body having a supply port, a return port, and a control pressure port, said control pressure port being in fluid communication with said subsequent valving component; an axial bore formed in said valve body and in fluid communication with each of said supply, return, and control pressure ports; a valve spool slidably supported within said axial bore of said valve body, said valve spool adapted to control fluid flow through said supply, return, and control pressure ports, and having symmetrical transition segments to simultaneously vary, for a given range wherein said supply port and said return port are in direct fluid communication with each other, the rate of change of area with respect to displacement of both said supply and return pressure ports upon being displaced, thereby providing a variable resistance to fluid flowing therethrough and reducing the quiescent power of said pilot valve, and wherein said valve spool is positionable to terminate fluid communication between said supply and control pressure ports; a motor that displaces, in a selective manner, said valve spool within said axial bore about said supply, return, and control pressure ports to apportion fluid therethrough to provide a desired control pressure to said subsequent valving component, wherein said motor urges said valve spool in a direction to open said supply port; and a feedback system having a feedback port in continuous fluid communication with said control pressure port and a feedback passage in continuous fluid communication with said feedback port and said valve spool, said feedback passage configured to receive pressurized fluid therein to act against said valve spool and to urge said valve spool in a direction to close said supply port with a negative feedback force on said motor.