A study on electromagnetic induced vibration of the three-phase induction motor for small cooling fans by experimental analysis (Reduction of electromagnetic induced vibration by magnetic wire specification)

Abstract

Recently, cooling fans have been used for not only general industrial machines but also precision machines, such as medical care products and optical equipment, and these generate more requirements about vibration limitations. The main vibration of cooling fans caused by rotating unbalance and resonance has been reduced, so electromagnetic induced vibration, which was not considered before, now has to be reduced. The purpose of this study is to control the electromagnetic induced vibration of 2 poles three-phase induction motors that rotate fast, such as for cooling fans. In this paper, it is shown that, the number of coils that is one of the magnet wire specification controls electromagnetic force and electromagnetic induced vibration by an experimental study of 2 poles three-phase induction motor that has an output of 70W, as follows; the difference of magnet wire specification can be quantified by the space distribution of magnetomotive force (SDMF), SDMF can be inferred from measuring data of magnetic flux by sensor wire method to be confirmed identical to the theory, the effective value of the difference between SDMF and a sine wave has correlation with electromagnetic induced vibration and increasing number of coils from 1 coil / pole / phase to 3 coils reduces the effective value of the difference between SDMF and a sine wave, and also reduces electromagnetic induced vibration about 20 dB.