Dynamic Study Of The Magnetically Support Cracked Rotor Sets

Rotor system is crucial part of rotating machine,so the running performance of rotorinfect system’s work efficiency.The reasonable designparameter and suitable work speedcould effectively reduce mechanical failure,in this paper we research in system’s nonlineardynamics to provide theoretical basis of parameter design and troubleshooting.Rotor system has strong nonlinear characteristics with many uncertain factors,the oil filmpressure and electromagnetic force are nonlinear,also undergo nonlinear influence of fatiguecracks,rub-impact fault and air turbulence,movement form will diversification by the changeof rotor speed,stiffness coefficient,damping coefficient and mass eccentricity.This thesis mainly studies dynamic study of the magnetically support cracked rotor sets,Compare with tradition rolling bearing and sliding bearing,magnetic bearing has severalremarkable advantages:higher mechanical transmission efficiency,lower friction loss,withoutlubrication,non-pollution,all of this meet new requirments of rotor system’s development.Willwidespread use in production, especially in some specialized application,in the bio-medicaland precise space electronic devices,which requirements of clean, high transduction efficiencyof special occasions. A mechanical model of rotor magnetic bearing system considering crackand rub-impact is established. According to Newton’s second law, the system’s differentialequation of motion is obtained.Application method of Runge-Kutta in simulation motionresponse.The vibration changed by ratio is analyzed by using bifurcation map,Poincaremap,time domain waveform and spectrum analysis.Through the analysis of the changes ingraphics we get the working space of period motion,quasi-periodic motion and chaos.Eachmotion state unstable by the change of different parameter,it is useful to design rotarymachinery and provide theoretical basis in fault identification and troubleshooting of practicalwork.