Novel Bidirectional Rotary Proportional Actuator for Electrohydraulic Rotary Valves

This paper presents a bidirectional rotary actuator for electrohydraulic rotary valves using permanent-magnet rotor with output torques and angular displacements proportional to the excitation currents. Finite-element analysis provides the static characteristics of the actuator and the analysis is coupled to a nonlinear time domain simulation to determine the dynamic performance. The measured and simulated results agree well and show that the actuator can produce torques up to plusmn0.65 Nm, linear angular displacements of plusmn8deg with hysteresis less than 4%, and frequency bandwidth (-3 dB) about 190 Hz.