Static and dynamic vibration analyses of switched reluctance motors including bearings, housing, rotor dynamics, and applied loads

This paper presents a thorough numerical study of vibration analysis in electric motors, with particular application to switched reluctance motors (SRMs), using three-dimensional finite-element analysis (3-D FEA) methodology. It covers the major vibration sources: mechanical, magnetic, and applied load. The following analyses are presented. 1) A 3-D modal analysis including stator and rotor structures, shaft, end shields, bearings, and housing. 2) An unbalanced rotor dynamics analysis of the rotor, which is important for deciding on the eccentricity of the rotor mass to ensure that the vibration of rotor and housing is within acceptable limits. 3) A harmonic analysis to identify the range of speeds producing high vibration and noise that should be skipped over quickly during acceleration. 4) A stress analysis under different loading conditions (a simulation of load testing) to predict the deformation of the shaft and rotor. Apart from frequently reported modal analysis on the stator of SRMs in two dimensions, these 3-D vibration analyses are essential to examine the vibration in SRMs as a whole.