Abstract: A model is presented for driving torque of asynchronous motors based on the principles of electromagnetism applied to electrical machines and a method is proposed for analyzing the sideband-structure of its vibration. Moreover, this paper discusses properties of vibration modulation and non-overlay of sidebands, Dealing with failure cases of asynchronous motors, this paper processes and analyzes real signals of vibration generated by various faults such as wear and unbalance of rotating shaft and voltage fluctuation. The results of experiments are consistent with theoretical conclusions. As a result of studying asynchronous motor vibration, the analytical method of sideband-structure can be applied to identify its characteristic frequencies, monitor its health conditions and diagnose its faults.

Key words: Asynchronous motor, Electromagnet, Vibration