Electromagnetic Vibration Subjected To Heterogeneous Air-Gap Electromagnetic Force Of Asynchronous Motor Rotor Supported By Flexible Bearing

In modern great industry, Motor is important equipment for power exportation. Special concerns have been continuously on its safely working. The resonance by electromagnetic force is a primary factor. Therefore, the study on the vibration of motor rotor subjected to electromagnetic force has important theoretical and practical significance.In this paper, electromagnetic vibration subjected to heterogeneous air-gap electromagnetic force of motor rotor supported by flexible bearing. Firstly, according to the Hertz's elastic contacting theory and method of the minimum squares, figure out the stiffness of deep groove ball bearing that as the support, Based on which to do whirling motion analysis of single-disk rotor. For the single-disk rotor supported by rigid and flexible support, solve for respectively its natural frequency using modal method, and counsel the influence of bearing stiffness and system damping to natural frequency. Research the critical speed of the single-disk rotor with eccentric mass by flexible support; propound how to regulate the bearing stiffness to keep the working speed off the critical speed.Secondly, on the basis of electromagnetic theory and the given motor size and electromagnetic parameter, get the radial direction electromagnetic force on the interface of stator and rotor, when the air-gap is homogeneous. And research its evolution along with angle and time under different outer voltage.Finally, according to the energy method, get the electromagnetic energy and electromagnetic force and electromagnetic flaming force when the air-gap is not homogeneous, the electromagnetic vibration equations of the no-load motor rotor whose Pole-pairs is four, supporting by flexible support are derived using Lagrange-Maxwell equation of no-conservative system. Solve and calculate them by means of programming, for the different bearing stiffness and outer voltage, Graph the variation curve of the vibration displacement, phase diagram, movement locus of rotor, electromagnetic force and electromagnetic energy. In addition, we get the regularity of aforementioned parameters amplitude at different eccentric mass and bearing stiffness.