DETERMINATION OF PRODUCTION REASONS OF VIBRATION AND NOISE LEVEL SCATTERING OF MASS-PRODUCED INDUCTION MOTORS

Abstract

ABSTRACT A considerable variation in noise and vibration data between members of a group of nominally identical mass-produced induction motors has been observed. The paper describes the analysis of production causes of vibration and noise level scattering, common to a small three-phase squirrel-cage motors. The presented method is based on dimensional chains of physical and geometrical quantities. The method is used to determine the contribution of dimensional and other parameters in the vibration and noise level scattering of induction motors A calculation procedure for the vibration velocity and sound-power level has been formulated. The mechanical and magnetic sources without neglecting the effect of stator frame, bearing shields and rotor residual flux harmonics have been considered. Analytical results are compared with experimental statistical results of two groups of nominally identical induction motors and good agreement is obtained. The method should be very useful for the industry for assessing the causes of excessive dispersion of vibration and noise level of mass-produced motors. The method can also be applied to vibration and noise data analysis of newly-designed machines.