Piezoelectrically actuated single-stage servovalve

The invention disclosed is a direct driven, smart material actuated servovalve providing very high actuation control bandwidth for moderate to large flow systems. The servovalve is comprised of a valve body and a valve spool, a smart material element such as a piezoelectric, electrostrictive or magnetostrictive material, and a mechanical lever. The lever is mounted to a pivot support in the valve body and is positioned relative to the smart material element and valve spool such that expansion/contraction motion induced into the smart material element enforces motion on the first end of the mechanical lever. This motion is amplified by the lever at the second end of the lever and drives the end of the valve spool. The resulting amplified motion causes the valve spool to shift along its longitudinal axis of sufficient distance to afford high bandwidth valve spool positioning on large flow valves. Localized spool position sensing and control electronics are further added to provide a self-contained, high bandwidth servovalve.