Research on Electromagnetic Vibration Behavior of Direct Current Motors

Electromagnetic vibration of Direct Current Motors (DCM) is one of main vibration and noise sources. Firstly, the vibration characters of DCM different from other type of electric machines are introduced in this paper. Expressions of electromagnetic forces and torques acting on the pole surfaces with unskew and skew rotor slots are also deduced from basic flux density expression and Maxwell intense force formula. Based on these, a new method to estimate electromagnetic vibration mode of different forces and torques with FEM is provided and validated by an example of DCM. Secondly, the electromagnetic vibration source waves and components are analyzed. Besides, vibration sources prediction of the prototype is obtained from transient analysis and some important conclusions mentioned above are proved by vibration test of DCM. In a word, Both conclusions and method on dealing with electromagnetic vibration problems can give a reference not only to low vibration DCM design but also to other electric machines vibration and noise treatment.