Elastohydrodynamic Lubrication And Dynamic Analysis Of Roller Bearing-rotor System

With the development of high speed,high precision and high service performance of modern rotating machinery,the operation stability of the bearing-rotor system has been widely concerned.As a key support of the rotor of the rotating machinery,lubrication of the rolling bearing has profound influence on stable operation of the rotor system.Therefore,this dissertation studies the elastothermohydrodynamic lubrication of rolling bearing and the dynarmic characteristics of roller bearing-rotor system under the condition of elastohermohydrodynamic lubrication.The main contents of the dissertation are presented as follows:1.The infinite length roller pair of elastothermohydrodynamic lubrication model is established.The Reynolds equation,film thickness equation,viscosity equation,density equation,load equation and energy equation are solved by the finite difference method.Then,the oil film pressure distribution,oil film thickness distribution and oil film temperature distribution are obtained.Meanwhile,the influence of the entrainment velocity,load and slide-to-roll ratio on the lubrication performance is investigated.2.The finite length roller pair of elastothermohydrodynamic lubrication model is established.The lubrication model is solved by the finite difference method.Then,the oil film pressure distribution,oil film thickness distribution and oil film temperature distribution are obtained.Meanwhile,the influence of the entrainment velocity,load and slide-to-roll ratio on the lubrication performance is studied.3 The bearing-symmetrical rigid rotor sy stem is modeled.The stiffness and damping of the roller bearing under the condition of elastothermohydrodynamic lubrication are obtained.The dynamic equation of the system is solved by the Newmark method.The orbit diagram,Poincare map and time series are obtained.Moreover,the nonlinear responses of the system are investigated.The research in this dissertation can provide the theoretical basis for dynamic design of roller bearing-rotor system under the condition of elastothermohydrodynamic lubrication.