Study On The Influence Of Wear Particle Contamination On The Running State And Performance Deterioration Of Rolling Bearings

Rolling bearings are important basic components of mechanical equipment in aerospace,transportation,wind power generation and many other fields.When affected by the environment,sealing,wear and other factors,its lubricant will inevitably be polluted by foreign materials,which will damage the performance of the bearing,and even lead to malignant accidents in serious cases.The bearing abrasive wear caused by pollutants directly causes the increase of bearing clearance and vibration,which is the main reason for the early failure of rolling bearings in many cases.At present,there are relatively few research results at home and abroad on the motion state and performance deterioration of bearings caused by abrasive wear.In this thesis,using a method of combining theoretical calculation,experimental testing and simulation analysis,taking the deep groove ball bearing installed in the horizontal two-roll comprehensive experimental rolling mill as the research object,the impact of wear particle pollutants on the vibration characteristics and wear state of the rolling bearing was studied,which has important theoretical significance and engineering value.The main research work of this thesis is as follows:1.Based on Hertz contact theory,considering the influence of bearing clearance change caused by abrasive wear,the dynamic model of the bearing system is established by using the centralized mass point method,and the displacement,velocity and acceleration vibration characteristics of the system are solved by using the fourth-order Runge Kutta method.2.With the horizontal two-roll comprehensive experimental rolling mill as the test platform,the research on the vibration characteristics and rolling force of deep groove ball bearing under the influence of silicon carbide abrasive particles of different sizes was carried out.The clearance of deep groove ball bearing was identified by using leadpressing measurement method,and the wear surface morphology of deep groove ball bearing after the experiment was detected by ultra depth of field microscope,and the influence rule of abrasive particle size on the vibration characteristics,rolling force,clearance and wear degree of deep groove ball bearing was analyzed.3.The virtual prototype model of deep groove ball bearing with different wear degree caused by different sizes of abrasive particles was established,and the influence rule of wear caused by abrasive particles on the vibration response of deep groove ball bearing was obtained and verified by comparison with the test results.The influence of radial force and bearing clearance on the load distribution of rolling element and the dynamic response of bearing vibration under different external excitation conditions such as bearing clearance,external load and speed were studied through numerical simulation.Through this research,the influence rule of the size of silicon carbide abrasive particles in the lubricating grease of deep groove ball bearing on the bearing vibration signal,rolling force,clearance and surface wear degree was obtained.The characteristic values that can effectively monitor the vibration of deep groove ball bearing with the change of the size of abrasive particles during no-load and rolling of rolling mill were found respectively,and the influence rule of the radial force and bearing clearance on the load distribution of the rolling element and the vibration response of deep groove ball bearing.The results can be used as a reference for vibration monitoring analysis,health status evaluation and control of deep groove ball bearings under the action of abrasive particles.