Permanent magnet toroidal motor (PMTM) is a novel spatial motor that integrates toroidal drive system and permanent magnet synchronous motor. The unbalanced magnetic pull (UMP) with planet rotor eccentricity is the main cause of vibration in PMTM. In this paper, the analytical model of magnetic field with planet rotor eccentricity is established with the consideration of magnetic flux leakage. The calculation results of eccentric magnetic fields are compared with simulation results of finite element model. Based on the Maxwell tensor method, the analytical model of UMP with planet rotor eccentricity is established. The changes of UMP with initial eccentricity are obtained. The UMP is analyzed with the effects of eccentric distance and angle. The transient variations of UMP are discussed with different eccentric situations respectively. In addition, both simulation and calculation results for UMP have a good agreement, which verifies the validity of analytical model.
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