CALCULATION OF STATOR RADIAL VIBRATION FOR A HYBRID STEPPING MOTOR USING 3D FINITE-ELEMENT METHOD

This paper presents results from radial force and stator radial vibrat ion calculations using the 3D finite element method. Because of the sp ecial construction of a hybrid stepping motor with both unipolar flux due to the rotor magnet and heteropolar fluxes due to the currents in stator poles it is treated as a 3D magnetostatics problem. The radial force in the air gap under each stator pole has been calculated by the Maxwell stress method. The variation of radial force under each pole with one rotor tooth pitch movement is analyzed by Fourier series to o btain the force frequency spectrum with magnitudes and phase angles. I t is then multiplied by the corresponding measured stator mobility val ues to obtain the stator radial vibration. The results are compared wi th experimental data and have shown a reasonable agreement.