Design and analysis of a permanent magnet slotted limited-angle torque motor with special tooth-tip structure for torque performance improvement

This paper presents a permanent magnet (PM) slotted limited-angle torque motor (LATM) with special tooth-tip structure for torque performance improvement. A magnetic equivalent circuit (MEC) for the PM slotted LATMs is obtained and implemented in the design process. Then, finite element method (FEM) is employed to validate the design equations and to analyze both cogging torque and armature reaction influence on torque performance of PM slotted LATMs. In order to improve torque performance including angular operation range and the peak torque, a special tooth-tip structure is proposed, which is obviously different from conventional tooth-tip shape of motor. Finally, a prototype machine is established and its experimental results are presented and discussed. The experimental results confirm torque performance improvement by utilized this special tooth-tip structure.