Research On Lubrication Performance Of Fluid Pivot Journal Bearing

Compared with the traditional tilting pad bearing,the structure of the fluid pivot journal bearing is simpler.The liquid film is used to support the floating of the bearing and avoid the wear of the fulcrum.Therefore,it has excellent stability and reliability,and is widely used in high-speed rotating equipment abroad.In this dissertation,the static and dynamic characteristics of fluid pivot journal bearing are studied,and the influence of bearing structure parameters on the lubrication performance of bearings is analyzed.The main research contents include the following aspects:1.Based on the structural principle of fluid pivot journal bearing,the possible floating state of the bearing pad is analyzed.Under the one-sided floating state of pad,the Reynolds equation of the inner and outer oil film is established,the expression of the oil film thickness is derived,and the distribution law of the recess pressure is studied.2.By combining the Reynolds equations of the inner and outer oil film,the flow balance,torque balance and force balance equations on both sides of the bearing are established,and the iterative algorithm of the static balance position of the bearing is given.Combined with the structural parameters and operating conditions of the bearing,the static characteristics of the fluid pivot journal bearing are analyzed,and the influence of preload factor and eccentricity on its static characteristics is obtained.3.The dynamic characteristic coefficient of the inner hydrodynamic oil film is solved by the perturbation pressure method.Through the flow balance in the recess,the mass conservation equation of the lubricating oil was established,and the stiffness and damping coefficients of the outer hydrostatic oil film were calculated.The effects of eccentricity,preload factor and widthdiameter ratio on the characteristics of the inner and outer oil films were obtained.4.The oil film area is meshed by WorkBench software,and the laminar lubrication performance of fluid pivot journal bearing is calculated and analyzed by Fluent software.The influence of bearing operating parameters on oil film pressure and bearing pendulum angle is obtained,and the influence of bearing operating parameters on bearing floating and bearing stability is discussed.