Permanent Magnets Design and Magnetic Field Analysis of Multi-disc Coreless Permanent Magnet Synchronous Motor

This paper presents a new multi-disc coreless permanent magnet synchronous motor whose permanent magnets are arranged in the “Halbach array”. Unit motor combined structure is adopted to simplify processing technology of the motor. Airgap magnetic flux density is increased taking advantage of high remanence and coercive force of NdFeB permanent magnet material and high gathering magnetism function of Halbach array. This also makes coreless motor possible. The structure and the characteristics of the motor using Halbach array are also introduced. The FEM analysis has been done to build the mathematical model and study the magnetic field characteristics of the motor. And finally the interrelated design parameters of permanent magnet and arrangement between unit motors are determined according to the results of die FEM analysis.