Novel bidirectional linear actuator for electrohydraulic valves

This paper presents a permanent-magnet actuator with bidirectional and high levels of linear force over short strokes. The actuator can be used in electrohydraulic valves. Its static and dynamic performances were analyzed by using two-dimensional finite-element magnetic field solutions that take into account the nonlinearity of the material. The measured and simulated results are highly consistent. Experimental results show that the prototype actuator can produce a force of /spl plusmn/60 N, its nonlinearity is less than 0.5%, and the hysteresis is less than 2% within a stroke of /spl plusmn/1 mm. The actuator's frequency response (-3 dB) can reach 150 Hz.