Magnetic circuit modifications in a disc-type brushless motor with co-axial flux in stator

摘要

Advantages of disc-type permanent magnet (DTPM) motors such as low weight and relatively high torque-to-volume ratio, have led to wide use of this type of motors, particularly in drives having highest requirements on energy conversion efficiency. In the previous paper of the authors, the influence of permanent magnet dimensions, pole shoe width and air-gap length on the torque has been analysed for the so-called basic (or prototype) version of the motor tinder consideration. The ripple-cogging torque was effectively reduced by selection of an appropriate permanent magnet width and air-gap length. A good agreement of the developed numerical model with the physical model of the motor has encouraged the authors to extend the numerical model to include magnetic circuit modifications. As a result, two modified versions of the motor have been designed on a basis of successful simulation experiments and consequently, two modified motor structures have been constructed. This work is devoted to analysis of properties of modified magnetic circuit structures of a DTPM motor with co-axial magnetic flux in the stator. In this continuation study, the 3D FEM calculation of the magnetic field distribution and assessment of the integral parameters are treated as a basis for analysing the motion properties of the considered motor versions.