Operation Analysis and Torque Performance Optimization of a Novel Self-Aligning Limited-Angle Vibration Torque Machine

This article presents a new machine topology configuration of a self-aligning limited-angle vibration torque permanent magnet (PM) machine (LAVM). This kind of machine has a simple structure including 4 pieces of PMs and 2 stator teeth. It can operate in a reciprocating rotation at a high frequency and generate high-frequency vibration torque. Unlike conventional limited-angle torque motors, the LAVM is naturally equipped with auto zero-returning (ZR) performance for its rotor can return to the initial position automatically when no current is applied. The LAVM also shows a resonance phenomenon for the vibration amplitude reaches the maximum in a certain excitation frequency. The operation principles and optimization of LAVM are analyzed through finite element analysis (FEA). To increase the zero-position torque and improve the auto ZR capacity, a sensitivity analysis is conducted first, and then the parameters of this machine are optimized in the aspects of applied current value, PM geometric, PM-pole angle, and overlap coefficient using the parametric sweep method. The analysis results can serve as the design guidelines of LAVM. Finally, the prototype machine is manufactured and tested to validate the theoretical analyses.