Dynamic Pressure Lubrication Performance Of Water-lubricated Thrust Bearings And Optimization Of Heterogeneous Surfaces

In recent years,water-lubricated thrust bearings have attracted the attention of scholars at home and abroad for their advantages of environmental friendliness,high economic safety,small temperature rise and low power consumption.Water-lubrication thrust bearing is mainly used in all kinds of pumps,centrifugal compressor,turbine generator and steam turbine in large rotating machinery equipment,etc.Its main function is to bear the axial load,is to maintain the stability and reliability of the key components of machinery and equipment,directly affect the normal operation of equipment and maintenance cycle.With the development of industrial technology,this kind of equipment gradually moves towards the direction of high speed and high power,forcing the water-lubricated thrust bearing to be under the condition of high speed and heavy load.Therefore,higher requirements are put forward for the bearing capacity,anti-friction effect and other lubrication performance of thrust bearing.In order to improve the lubrication performance of thrust bearing,the slip/no-slip heterogeneous surface theory is introduced in this paper.Considering the boundary slip effect,the dynamic pressure lubrication performance of thrust bearing pad is studied.Firstly,considering the boundary slip effect,the mathematical model of flow field dynamic pressure lubrication for thrust pad of thrust bearing is established,and the numerical solution of the extended Reynolds equation,namely the finite difference method,is given.Through MATLAB calculation and simulation,the distribution law of pressure and shear force on the surface of thrust tile and its formation mechanism are analyzed.The effects of water film thickness,thrust shoe inclination and bearing speed on bearing capacity,friction force and friction factor of thrust bearing are studied.Secondly,the slip/no-slip heterogeneous surface theory is introduced to establish different heterogeneous surface distribution schemes,demonstrate the feasibility of slip/no-slip heterogeneous surface theory in the design of bearing thrust pad,and analyze the generation mechanism and variation law of dynamic pressurelubrication of thrust pad.Finally,a scheme of heterogeneous surface with slip-length and multiple slip-length is established respectively,and the influence rules of the area ratio,radial length ratio and the order and quantity of the slip-area on the bearing capacity and friction factor of the thrust pad are analyzed and compared,so as to optimize the design of the heterogeneous surface of the thrust pad.Through research and analysis,the change rule of lubrication performance and related slip parameters after optimization were obtained,which provided a technical reference for the design of heterogeneous surface of thrust shoe of water-lubricated thrust bearing.