Development of a Limited-Angle Torque Motor With a Moving Coil

Abstract

This paper presents a novel limited-angle torque motor (LATM) with a moving coil for oscillating mirror system. The proposed LATM has a constant torque coefficient over its operation range, rapid dynamic response, and easy mounting oscillating mirror owing to a special structure of the stator and the rotor. In design process, some design equations are derived to analyze toque coefficient, moment of inertia, and other parameters of the LATM. A novel optimization approach is carried out to obtain the maximum torque/moment of inertia ratio in consideration of the stator outer diameter and volume limitations. Coil parameters have also been optimized by this method so that a less time constant can be obtained. In addition, 3-D finite-element analysis is performed for verifying the proposed optimization method. Finally, a prototype machine is accomplished and its experimental results are presented and discussed. Meanwhile, a conventional position closed loop system of the LATM is established to validate the dynamic performance of the LATM.