Patent ID: 7455075
Filing Date: 2008-11-25
Classification: F16K,Y10T

Abstract:
1. A servo valve, comprising: a chamber having first and second end caps with first and second pilot valve seats with openings to first and second ports; a force motor comprising a stator having a stator coil and forming a cylindrical portion of said chamber, wherein said force motor further comprises: an armature assembly moveable inside said chamber in response to a current in said stator coil, wherein said armature assembly is held on either end of said chamber with elastic members, wherein said armature assembly comprises: wherein each of said plurality of pilot valves is formed when a pilot interfaces with one of said first and second pilot valve seats; said plurality of guide/stops forms a portion of said stator of said force motor; plurality of magnets are magnetically polarized axially in opposing directions; a third port coupled to said chamber and configured to receive fluid under pressure; and surface features located on said armature base and on one of said plurality of guide/stops, wherein said surface features are sloped to modify a magnetic path of first and second air gaps and leakage paths between said one of said plurality of guide/stops and said armature base whereby the linearity of a magnetic force to an applied input current can be adjusted by adjusting said surface features,