Acoustic Behavior of Squirrel Cage Induction Motors

The evaluation of distinct influences to the acoustic noise emission of industrial standard squirrel cage motors is fairly a very sensitive and complex topic. Main interest is thereby given to the influence of the complete mechanical induction motor design to the almost manifold acoustic response under sinusoidal power supply. This includes the investigation of unexpected effects even caused by passing critical speed values which are corresponding to mechanical resonance frequencies. To take remedial measures, totally-closed stator topologies and rotor skewing opportunities, have been deeply investigated in a comparatively manner. The performed comparatively measurement of the speed dependent equivalent continuous A-weighted surface sound pressure level gives a good overview about the principal design influences.