Variable-airgap, cylindrical, linear variable reluctance actuators for high-force, medium-stroke applications

This study describes a design feature for variable-airgap, cylindrical, linear variable reluctance actuators, which enhances their force capability at large airgaps. These features enable the actuators´ force-displacement characteristics to be tailored to the requirements of a particular application. The method presented is based on incorporating a series of circular grooves into the stator pole faces and corresponding projections into the armature. The utility of these features is demonstrated by means of a design study on an actuator with a rated force of 1 kN over a stroke of 3 mm. The findings from the design study are validated by experimental measurements.