A disc-type motor with co-axial flux in the stator: - influence of magnetic circuit parameters on the torque

摘要

This paper presents a three-dimensional analysis of the magnetic field distribution for a three-phase, disc-type, permanent-magnet, brushless DC motor with co-axial flux in the stator. Calculations are carried out using the 3-D finite element method (FEM). The electromagnetic torque is determined from the Maxwell stress tensor. For comparison, various dimensions of permanent magnets, pole shoes and air gap are analysed. It is shown that the ripple-cogging torque can be effectively reduced by an appropriate permanent magnet width and air-gap length. The simulation results are in good agreement with experimental data obtained from the prototype motor.