The Study of DC Motor Noise and Vibration

The noise and vibration characteristics of permanent magnet direct current motors along with the associated primary sources of noise, vibration and transmission paths are presented in this paper. Included are various methods and techniques to reduce or attenuate the levels of noise and vibration which emanate from the motor. The sources of noise and vibration are the results of the interactions from the brush and commutator, the gear and worm meshing characteristics, and the armature shaft and bearing system. The noise and vibration emanating from the motor sources are transmitted to the motor housing, supporting mounting structures, and subsequently radiated into the environment. The various methods found to significantly reduce the levels of motor noise and vibrations from their sources are discussed in detail.