Experimental Study On Wear Of Journal Bearing Of Roter System With Torque Excitation

Large rotating machinery,such as Gas turbines,fans and compressors etc,are the key equipment in machinery,power,petrochemical and other industries.As the turbine-generator unit and other large equipment are increasingly slenderized and more complex,the large torque is easily acted on shafts repeatedly in the rotor system.Under the excitation of torque frequently,wear of journal bearing rotor system will be changed obviously,which affects the stability of rotor system.So,the study of wear test of journal bearing the rotor system under torque excitation can effectively monitor the rotor system and ensure the safe transportation of the rotor system.The study of wear test of journal bearing the rotor system under torque excitation was carried out in the single span double disc rotor test rig,some studies have been carried out as followed.(1)Considering the nonlinear oil film force and the influence upon the rotor system of elastic supporting system,the variation of load of journal bearing supporting with the constant torque of different amplitude were studied.The oil film pressure and oil film the thickness of the shaft-journal bearing friction pair with the constant torque of different amplitude were analyzed by simulation,and the lubrication of of the shaft-journal bearing friction pair was calculated.The experiment was carried out in the single span double disc rotor test rig,the concentration data of the wear debris of journal bearing on the iron spectrum were extracted and wear particle concentration change trend was predicted by combination forecasting model and the forecast results of the forecast model were compared.The rotor system with the constant torque of different amplitude were tested,oil sample of rotor test were collected and analyzed by Ferrography.The typical characteristics of wear particle of journal bearing with torque excitation were find out.Through the experiment,the characteristics of abrasive particles of journal bearing are summarized and the wear mechanism of journal bearing with torque excitation is studied.(2)According to the variation law of wear particle concentration in journal bearing of rotor system with torque excitation,a least squares support vector machine regression,grey forecast and exponential smoothing method were adopted to predict of wear particle concentration variation of journal bearing.A combination forecasting method based on IOWGA operator was adopted and the forecasting model of abrasion wear particle concentration of a rotor system and the evaluation index system was established.The results show that the prediction accuracy of the combined forecasting model based on IOWGA operator is higher than that of the three single forecasting methods,and the effect is better.It makes up for the deficiency of single prediction model and it is an effective method to predict the particle concentration in lubricating oil.(3)The impact factors of journal bearing wear and wear life in the rotor system were analyzed,and the effect of wear life of journal bearing of rotor system with torque excitation was studied.The experiment was carried out in the single span double disc rotor test rig,wear of journal bearing of rotor system with the constant torque and speed of different amplitude were measured.Based on theory of the classical Archard wear model,an improved Archard wear model was proposed.The wear life prediction model of journal bearing of the rotor system was established by calculating the relationship between the wear rate of journal bearing with the constant torque and speed of different amplitude.It is believed that the knowledge gained in this study will provide reference for repairing or changing of journal bearing of the rotor system.