Research On Loading Carrying Characteristics Of Foli Gas Thrust Bearing Based On Contact Mechanics

Foil gas thrust bearing is a kind of high-speed bearing with elastic structure as a support.It is widely used in aerospace,air circulation,high-speed turbine machinery.Foil thrust bearings have many theories of structural design and analysis theory.However,this kind of multi-layer foil gas thrust bearings which will be study in this paper,few research is found in China and abroad.Its working principle is similar to that of the bump foil bearing,but the structural design is different.Therefore,new structural theories need to be used.The main work of this paper is to derive a new theory to calculate its static characteristics and optimize its structural parameters.Like all of gas bearings,the multi-layer gas-dynamic thrust bearing,rotor rotated to drive gas flow between the bearing and the rotor to generate hydrodynamic pressure effect.However,the multi-layer structure design makes the deformation of the foil structure affect each other.The calculation of foil deformation cannot simply be equivalent to the spring model.In order to fit the practical calculation of the performance of this kind of bearing,the fan-shaped thin plate model theory was deduced first,and contact mechanics of every layer was study.A series of numerical calculations have been carried out to compared with the results of ANSYS simulation to verify the feasibility of the theory.After the structural model is established,the gas dynamic Reynolds equation and the film thickness equation are established under the cylindrical coordinates.The finite difference method is used to solve the Reynolds equation on the fan-shaped area to get the film pressure and film thickness.Using the method of weak coupling,the model of the structure and the gas equation are solved simultaneously,and the characteristics of the bearing under stable operation are obtained.According to the static characteristics,the difference between multi-layer bearing and bump bearing is analyzed,and the deformation and contact characteristics of multi-layer bearing are analyzed emphatically.In order to guide the design of the bearing,the influence of various structural parameters and flow field parameters on the bearing characteristics and friction characteristics are studied.After calculation,the most suitable structural parameters are proposed.And use these parameters to manufacture a thrust bearings,set up a test platform and test,The final experimental results and calculation results are within the allowable range of error,which proves the feasibility of the calculation results.