Abstract
This study deals with a newly proposed electro-magnetic proportional actuator for hydraulic control valves, in which multi poles are arranged in a row. The force produced by this actuator is more than 2.5 times as large as that of conventional proportional electro-magnetic actuators of solenoid type. Performances of this actuator have been reported in previous papers. In this paper, influences of dimensions such as clearance between stator and armature, thickness of the armature and length of the top land of the armature are investigated experimentally. It becomes clear that the produced force increases with reduction in the clearance between stator and armature. Moreover, influences of the thickness of the armature are not so large as long as the length of the top land is smaller than 40% of the thickness of the armature. The results in this paper will be profitable for designing the actuator.