Analysis of an Axial-Flux Slotted Limited-Angle Torque Motor with Quasi-Halbach Array for Torque Performance Improvement

Better torque performance and higher reliability have long been the focus of research for slotted limited-angle motors (LATMs), which are primarily used to position first-stage valves in electrohydraulic servosystems. This paper presents a high axial-flux LATM with quasi-Halbach array improvement including constant range (CTR) output torque. Firstly, structure two sets windings operation principle proposed is analyzed. Secondly, brief design procedure presented, selections open slot double-stator single-rotor (DSSR) interior rotor surface mounted permanent magnet (PM) illustrated, geometric parameters optimized obtain optimal LATM. Then, 3-D finite-element method (FEM) employed compare conventional PM terms cogging torque, no-load back EMF, results show that has 10% 25% CTR. Meanwhile, flux linkages under various conditions verify good magnetic isolation. Finally, prototypes different types manufactured series experiments performed validate analysis.