Research On Dynamic Characteristics Of Rotor-Bearing System And Bearing Wear Coupling Characteristics

Bearings are important supporting components of rotating machinery such as aero engines,vehicle engines,and gas turbines.The healthy operation of bearings is the basis for ensuring the normal operation of rotating machinery.Wear is one of the main factors leading to bearing failure.Wear reduces the operating accuracy of the bearing and rotor system,and significantly affects the operating reliability of the entire rotating equipment.The research on bearing wear in the rotor-bearing system and the dynamic characteristics of the rotor system are of great significance for exploring the evolution of bearing wear and troubleshooting wear affects the dynamic response characteristics of the rotor system,and the rotor system with bearing wear provides an important theoretical basis.In this paper,two angular contact ball bearings support the rotor-bearing system as the research object,the bearing wear depth study of evolution and the rotor system dynamic characteristics of rotor system under the rotor speed,bearing preload and preload parameters and influence turntable position.The EMD method is used Combining the spectrum analysis method to analyze the wear failure of rolling bearings.The specific work mainly includes:(1)Based on Lagrangian equations,a dynamic model of a five-degree-of-freedom rotor-bearing system is established.In the dynamic model,the rotating shaft is regarded as a rigid body,and the mass of the rotating disk and the rotating shaft is concentrated in the center of the rotating disk;by establishing the relationship between the contact force and contact deformation of the rolling element and the raceway inside the bearing,the force of the bearing on the rotating shaft is obtained.(2)Based on the classical model of Archard,inside and outside the rolling bearing raceway wear depth calculation model was established.In this calculation model,the contact pressure distribution and sliding speed distribution of the contact interface between the rolling elements and the raceway are fully considered,and the influence of lubrication on the wear coefficient is introduced to establish a wear model suitable for the calculation of the wear depth of the ball bearing raceway.(3)The coupling analysis method of bearing wear evolution and rotor system dynamic response is proposed.On the one hand,the bearing raceway wear depth is calculated based on the contact parameters and speed parameters between the rolling elements and the raceway inside the bearing obtained by the dynamic analysis;on the other hand,the raceway wear depth obtained is regarded as the bearing clearance and introduced into the rotor-bearing The system dynamics model analyzes the dynamic response of the rotor system under wear.The two analysis processes alternately carry out the coupling analysis of bearing wear and system dynamic response.(4)Based on the dynamic model and the wear depth model,according to the proposed method of coupling analysis,Rotor speed dynamics influence the turntable bearing preload and location parameters rotor system bearing wear and rotor system.The system was studied.The results show that the influence of the bearing characteristics of the rotor dynamic bearing system is close to the rotor speed and load preload;rotor speed has a significant influence on the bearing wear,bearing preload little effect on the bearing wear.Changes in the position of the turntable will not cause changes in the dynamic characteristics of the rotor.Bearing wear depth of the significant changes.(5)The EMD method and the cross-correlation analysis method are introduced,and the EMD analysis of the simulation signals under different wear amounts is carried out.Based on the early wear failure characteristics of rolling bearings,the EMD method combined with the frequency spectrum analysis method is used to analyze the wear failures of rolling bearings.The results show that with the increase of the amount of wear,the proportion of the fault frequency component of the inner ring of the system gradually increases,and the component of the rotation frequency gradually decreases.