Vibration Analysis of An AFPMSM with Two Contra-rotating Rotors

This paper aims to investigate the vibration performance of an axial flux permanent magnet synchronous machine (AFPMSM) with two contra-rotating rotors. A rapid analytical model of the electromagnetic forces acting on the tooth tips of the AFPMSM is proposed. The nodal forces distributing on the teeth are converted into radial, tangential and axial concentrated forces. Furthermore, the force modulation effect of stator teeth is considered during the analysis. On this basis, the radial and axial vibration accelerations excited by the forces in different directions are obtained and compared. The results show that the forces in any direction can cause both the radial and axial vibrations. Finite element analysis (FEA) and experimental tests are conducted and the results validate the correctness of the proposed analytical model. Besides, the vibration performance of the machine is investigated. The proposed analysis method and vibration study are benificial to the identification and reduction of vibrations in PMSMs