Study On Dynamic Characteristics Of Rotor System With Foundation Looseness

In the rotating machinery,the rotor system often has rubbing and loosening faults,so rubbing and loosening affect the stability of the rotor system operation.Oil film force,rubbing force and looseness all show nonlinear characteristics,so that the rotor system also has a certain nonlinearity.In the system,the change of parameters will cause the dynamic behavior of the rotor system to change.Therefore,it is of great significance to study the changes of the parameters of the rotor system's dynamic behavior.This paper mainly studies the dynamic characteristics of the rotor system based on the foundation looseness.Firstly,this paper studies the rotor system model with one end loose under the action of rubbing force,and lists the dynamical differential equations of the system and carries out non-dimensionalization of the equation.Through numerical simulation and simulation,the dynamic behavior of the rotor system is deeply studied and analyzed.Based on the benchmark parameters,the paper selects variable parameters,draws the system's bifurcation diagram,axial orbit diagram,Poincaré cross-section map,etc,and studies and analyzes the influence of the system's dynamic parameters on the dynamic characteristics of the system.The changes in the system stiffness ratio,mass ratio,eccentricity,bearing end damping coefficient,etc,have a great influence on the dynamic characteristics of the loose rotor system.The research and analysis show that:(1)As the stiffness ratio increases,the stability of the system decreases gradually.(2)As the value of the damping coefficient increases,the stability of the system increases gradually.(3)When the friction coefficient is moderate,The system is in periodic motion.When the friction coefficient is larger or smaller,the stability of the system is gradually reduced.(4)When the mass ratio is small,the chaotic motion of the rotor system occurs in the medium speed range,increasing the mass ratio value,the chaotic motion area.Diffusion and a larger range,further increasing the mass ratio,the chaotic movement area has been reduced.Secondly,the dynamic behavior of loose rotor model at both ends under oil film force is studied and analyzed.The system dynamic differential equations are listed and the equations are dimensionless.Through numerical simulation and simulation,the dynamic behavior of the rotor system is deeply studied and analyzed.Based on the benchmark parameters,the paper selects variable parameters,draws the system's bifurcation diagram,axial orbit diagram,Poincaré cross-section map,etc,and studies and analyzes the influence of the system's dynamic parameters on the dynamic characteristics of the system.The changes in the system stiffness ratio,mass ratio,eccentricity,bearing end damping coefficient,etc,have a great influence on the dynamic characteristics of the loose rotor system.The influence of various parameters on the system can be roughly summarized as:(1)As the system stiffness ratio,mass ratio,and eccentricity value gradually increase,the chaotic motion area of the system gradually increases the stability of the system gradually decreases.(2)When the damping coefficient of the bearing end is small,the chaotic motion region of the rotor system is larger,the system is in an unstable state,and then the damping coefficient is increased,the chaotic motion region is gradually reduced,and the stability of the system motion is improved.