Patent ID: 6526864
Filing Date: 2003-03-04
Classification: F16K,Y10T

Abstract:
A direct drive servovalve comprising:a valve body, a valve spool having a longitudinal axis, a sleeve, a smart material element, and a mechanical lever having first and second ends wherein the lever is mounted to a pivot support means and the lever is positioned relative to the smart material element and valve spool such that expansive motion induced into the smart material element enforces motion on the first end of the mechanical lever such that the first end motion is amplified by the lever at the second end of the lever and the second end of the lever drives a spool linkage which in turn drives the end of the valve spool causing the valve spool to shift along its longitudinal axis a distance commensurate with the amplified motion of the second end of the lever, wherein the spool linkage passes through the center of the valve spool and attaches to the far end of the valve spool relative to the mechanical lever, and wherein the sleeve surrounds the valve spool and nests within the valve body and the sleeve is longitudinally positionable relative to the valve spool such that the smart material element determines the valve spool position through the mechanical lever and wherein fine tuning of the relative position of the valve spool to the valve body porting is performed by positioning of the sleeve relative to the valve spool.