Study On Influence Of Non-uniform Film Thickness Carrying Characteristics Of Heavy-duty Hydrostatic Thrust Bearings

With the transformation of China’s modern manufacturing industry,the country pays more and more attention to the processing of heavy and super heavy rotary parts.Hydrostatic thrust bearing is the core equipment for processing rotary parts,and its accuracy,reliability,lubrication performance and load-bearing performance will be the main focus of research.In the working process of hydrostatic thrust bearing,the main role of hydraulic oil is to support the workbench and lubricate the friction pair.When the working speed is too high or the load is too large,the oil film will become thin,leading to the decline of workpiece processing quality,and dry friction will occur in serious cases,leading to the friction failure of hydrostatic thrust bearing.Therefore,it is of certain practical significance to explore the variation law of lubricating oil film morphology in the working process and the influence of oil film deformation on the lubrication and bearing characteristics of hydrostatic thrust bearings.The oil film equation of hydrostatic thrust bearing was established according to hydrodynamics and heat transfer.The oil film flow and temperature rise equations were deduced theoretically,and the numerical relationship between oil film thickness and bearing capacity was constructed.CFX module was used to establish the simulation model of hydrostatic thrust bearing heat transfer,and the temperature field and oil film pressure field in the solid domain were obtained.The calculated results obtained from CFX were taken as the initial conditions for statics analysis and imported into the Static Structural module of Workbench platform to obtain the deformation field in the solid domain.The deformation of the solid domain will change the node displacement field of the fluid domain,that is,the oil film thickness will change.The deformed oil film model will be extracted and the above operations will be repeated.Multiple unidirectional fluid-structure coupling simulation was carried out by using the method of iterative oil film thickness,and the convergence threshold of multiple simulation was calculated by sorting out the simulation data.It is found that during the working process of hydrostatic thrust bearing,with the increase of the rotating speed of the workbench,the maximum temperature of the oil film gradually increases,the average pressure of the oil film increases first and then decreases,the deformation trend of the solid domain appears outward and oblique upward,and the oil film has the first uneven deformation.In the process of multiple iterations,the oil film gradually becomes thinner,showing a deformation trend of thinner inside and thicker outside.The average pressure gradually increases,the average temperature is almost unchanged,and the maximum temperature changes slightly.The solid domain always maintains an outward and oblique upward deformation trend.According to the oil film variation law obtained,it provides an important theoretical basis for improving the working stability of the hydrostatic thrust bearing,improving the machining accuracy of the workpiece and predicting the friction failure of the hydrostatic thrust bearing.