The Noise and Vibration Analysis of BLDC Motor Due to Asymmetrical Permanent Magnet Overhang Effects

This paper relates to a vibration analysis of brushless DC (BLDC) motors using the asymmetrical Z-axis overhang of permanent magnet. In BLDC motor, the asymmetrical Z-axis overhang of permanent magnet generates Z-axis thrust which leads to Z-axis eccentric force by commutated current on the rated load and then the Z-axis vibration. The Z-axis thrust ripple, the source of Z-axis vibration under commutated current, is analyzed by using 3-Dimensional Finite Element Method (3-D FEM), and the phenomena of Z-axis vibration is analyzed by experimentation.