Servo valves

Abstract

An electrohydraulic servo valve generally comprises an electrical torque motor, a flexible member and a rigid beam arranged to control a flow of hydraulic fluid into a hydraulic block, and a spool slidingly mounted in the hydraulic block for axial movement in response to a differential pressure. The torque motor includes a drive member connected to the rigid beam and moveable to deflect the beam and flexible member in response to an electrical input. According to this disclosure, a feedback spring is directly connected to the beam so as to transmit a return force in response to movement of the spool. The feedback spring is a one-piece spring member fixedly attached to the spool and arranged to absorb radial displacement of the spool within the hydraulic block.

Dependencies are inferred from the claim text.