2014 年 80 巻 820 号 p. DR0383
In this paper, the phenomenon of vibration and noise in a small fan motor caused by electromagnetic forces were experimentally investigated. First, vibration characteristics of the fan motor in a non-operating state were determined by experimental modal analysis. Next, vibration and noise characteristics of the fan motor in an operating state were determined. The rotational speed was continuously decreased from 2200 r/min to 1200 r/min while the measurements were taken. A detailed frequency analysis was also performed to investigate the directional patterns of noise at the rotational speed which the significant resonance were confirmed. In addition, analysis on the vibration and noise of the fan motor after turning off its power were performed. As a result, it was found out that the significant vibration and noise were generated in the axial direction, and were resonance phenomena between harmonic frequency of electromagnetic force and natural frequency of the fan.
