Analysis And Experimental Study On Roundness Error And Cylindricity Error Of Journal Bearing Rotor System

Nowadays,the development of machinery industry is moving towards high-speed,high-precision.Higher requirements was put forward to the rotating machinery,the very important part of machinery industry.In rotor system supported by journal bearing,the bearing manufacturing error directly affects the operating characteristics of the system.Roundness and cylindrical degree are the important components of manufacturing error.Hence,the system dynamics Models corresponding to those errors must be established to study.Firstly,the ideal circular model of the rotor-bearing system was established based on the nonlinear analysis theory and method of the rotor-bearing system.The finite difference method was used to solve the Reynolds equation.The oil film pressure was obtained and then the oil film force was obtained.The rotor’s displacement,velocity,acceleration at any time were obtained through Newton’s law.And then obtain the axis trajectory and the critical speed of the system.Based on Sommerfelds Number,the dimensionless stability operation parameter Op was used to describe the stability characteristic of the system.And the stability curve is generated.Bearing capacity,friction energy loss power were also analyzed.On this basis,three kinds of dynamics models of rotor-bearing considering the random roundness error are established.And the upper model was chosen as the model of random roundness error through analyzing and comparing with the others.The rationality of the finite difference meshing of the upper model was verified.The influence of random roundness error on system stability,friction power and carrying capacity is analyzed.The model of stochastic cylindrical error rotor system is established,and the rationality of finite difference meshing is obtained,and its influence on stability and friction power and carrying capacity of the system is analyzed.Finally,the correctness of the random roundness error and the random cylindrical error of the rotor system model is verified by the experimental bench test,and the random roundness error is verified.And the stability of system improved due to the existence of some random roundness error and the random cylindrical error.The research of this thesis has improved the study of manufacturing error influence on the rotor-bearing system,which is of reference value for the analysis and diagnosis of sliding rotor equipment.It provides theoretical support for designing rotor structural,extending rotor life,manufacturing and so on.