Dynamic Modeling And Vibration Spectrum Analysis Of Angular Contact Ball Bearings Under Axial Load

The operation condition of angular contact bearing is the key of whether the mechanical can work well.In this paper,the failure mechanism and running state of the bearing is studied in space environment.As in space environment it is unable to obtain bearing running condition information,so the simulated space environment bearing vibration information are got and analysised,so as to choose a optimal bearing from a large number of candidate installed in the spacecraft.At present,the life state monitoring methods of solid-lubrication rolling bearings in the simulated space environment include friction torque test and temperature test.However,the friction torque and temperature include a single bearing life characteristic information,are insensitive to the performance degradation of the bearing during the normal life cycle,and cannot effectively reflect the deterioration of the bearing performance.The vibration test has been paid attention to as a means to monitor the life status of the solid-lubrication rolling bearing under the simulated space environment.It has great potential in the characterization and prediction of the life of the solid-lubrication rolling bearing.The dissertation focuses on the problems of precision failure and difficulty in assessing the life status of space rolling bearings.Based on the vibration signal as the footing point,the dynamic model of the ground-simulated space rolling bearing is established and the failure mechanism is analyzed.The main characteristics of the vibration signal of bearing failure accuracy are summarized,and the evolution process of the bearing vibration signal with the wear status was analyzed and modeled.Then the vibration data of the bearing in the simulated vacuum environment were compared and verified.The specific research content is as follows:1.The load of the angular contact bearing,the fluctuation of the rotational speed and the aggravation of the wear caused the failure of the bearing.The thesis analyzed the wear of the bearing under the static conditions such as the change of the curvature radius of the bearing,the contact force and the change of the contact torque through the analysis theory of the angular contact bearing.The change of the vibration signal in the state can reveal the basic running performance of the bearing.2.The oil film thickness of angular contact ball bearings under the steady-state EHL condition is studied.The stiffness and damping characteristics of the ball-raceway contact pair are discussed in detail.The total stiffness and total damping of the angular contact ball bearing system were determined and the vibration equation of the angular contact ball bearing was obtained.3.Based on the theory of statics analysis,this paper establishes the dynamic model of angular contact bearings and presents transients for the contact angle of the ball.Analyze the traction and interaction forces generated by the contact of the steel ball with the stiffness and analyze the effect it will have on the running characteristics of the bearing.4.In order to analyze the dynamic characteristics of the bearing in a simulated vacuum environment on the ground,the properties of the solid lubricant particles are discussed.The generalized Reynolds equation is established to analyze the traction force variation model of the elliptical contact area of the solid lubrication bearing,and the accurate description of the contact form of the solid lubrication space rolling bearing is realized.5.Through the angular contact ball bearing vibration test system,the bearing vibration signal is collected to analyze the time domain characteristics and frequency domain characteristics of the vibration signal.In combination with the established model,the vibration spectrum of the angular contact ball bearing is analyzed to establish a basis for more detailed analysis of the bearing spectrum.In the end,the article summarizes the work of this article and looks forward to the next research direction.