Detent force minimization of a novel linear-rotary permanent magnet actuator with independent magnetic circuit structure

The paper proposes a novel linear-rotary permanent magnet actuator (LRPMA) with independent magnetic circuit structure, which can decrease the coupling relationship between the permanent magnet flux path and armature flux path, and of the adjacent phases. The thrust force of the LRPMA can be improved by changing the distance between the stator segments in the axial direction. A 3D ideal model is built for analyzing the magnetic flux density and a simplified model of one section for thrust force calculation is built, and the expression of cogging force, end force, normal force are derived by analytic method and Maxwell stress tensor method. The simulated results show that the detent force can minimized when the distance between the stators in axial direction, which has the similar results of that analyzed by finite element method.