Transient Coupling Study Of Dynamics And Tribology On Sliding Bearing

The radial sliding bearing of rotating machinery has been the main research topic in the field of tribology.In the analysis of the bearing lubrication,the oil pressure and bearing temperature will respectively cause the elastic deformation and thermal deformation of bearing bush and journal,which lead to the change of oil film thickness.When the oil pressure and bearing themperature reach a certain degree,it needs to be considered that the change of lubricating oilviscosity and density with temperature and pressure.Therefore,it is necessary to introduce the thermoelastic hydrodynamiclubrication theory in the lubrication analysis of the radial sliding bearing.For dynamic load sliding bearing under variable condition,the changing operating condition,such as shaft rotational speed and journal load,will cause the difference of bearing lubrication status.Then,it needs to introduce the time factor on the basis of thermoelastic hydrodynamiclubrication theory,which establishes the transient thermoelastic hydrodynamiclubrication theory.In conclusion,the lubrication analysis of radial sliding bearing is a four-dimensional mathematical problem.The dissertation introduces the transient analysis model of radial sliding bearing lubrication research,which uses the generalized Reynolds equation based on the average flow model to carry out the oil pressure calculation considering roughness of the lubrication surfaces,derives the energy equation of lubricant oil and the heat conduction equation of bearing bushto carry out the bearing temperature calculation.The transient thermoelastic hydrodynamiclubrication model on sliding bearing are built by means of combining the Reynolds equation,bearing energy equation,and journal movement equation.Thedimensionless equations are adopted to improve the numerical stability,and the finite difference method is used to discrete the dimensionless equations.The decoupling calculation method is designed by analyzing the coupling relationship among bearing dynamics and tribology.The calculation procedure is compiled using Fortran language.Compared with the previous calculation model and experimental data,the steady and transient state calculation results of the model in this dissertation are more consistent with the experimental data,which can verify the accuracy of the model.The bearing dynamics and tribology properities under several typical changing operation conditions are considered,including journal rotation speed increases,the impulse load and dynamic unbalance quality.The dissertation gets the following conclusions.In the process of journal rotation speed raising,larger rotation speed raising will increase the possibility of journal eddy,and larger early speed can greatly reduce journal running stability,and the increase of load will enhance journal stability.