Electromagnetic Vibration of Small Squirrel Cage Three-Phase Induction Motor

Abstract

The small squirrel cage three-phase induction motor has been used in all types of industry for a number of years. Motor radial vibration and noise caused by electromagnetic force are addressed in this paper.
At first, the frequency of the harmonic fluxes, which are main factor of vibration and noise, is discussed. Then modes and frequencies of electromagnetic radial force wave, induced by these harmonic fluxes, were calculated.
Natural frequency responses and modes of experimental motors were measured. Also frequencies and modes of vibration were measured on a running experimental motor. The experimental data was compared with the calculated values.
As a result, it was newly confirmed that modes of the running motor were determined to be a function of the natural frequency mode of the structure, not by modes of the electromagnetic radial force wave. It became clear that these modes did not rotate around the core. They were stationary waves.