Reducing the Noise and Vibration of the BLDC Motor's Stator by Shifting its Natural Frequencies to Higher Values

Regarding the necessity of low noise and low vibration operation of the BLDC motors in some especial applications, a novel method is proposed in this paper in order to shift the natural frequencies of a BLDC motor’s stator to higher values. Therefore the noise and vibration of the structural resonances can be reduced since the electromagnetic excitation forces in the BLDC motor have lower magnitudes at higher frequency components. The proposed method is based on placing a single hole, with definite diameter and location, on definite regions of the stator cross sectional area (each region contains one stator tooth and its upper parts in the stator’s yoke). The frequency analyses have been done in the SolidWorks software environment and the best diameter and location of each hole is extracted by the Response Surface Methodology (RSM).Preventing the magnetic saturation of the stator structure and the motor cogging torque enhancement prevention are considered as constraints for the problem. The new method also can be used for other types of electrical machines’ stator.