Analysis Of Static And Dynamic Characteristics And Parameter Optimization Of Spiral-grooved Gas Journal Bearing

As a type of dynamically-pressurized gas bearing with excellent comprehensive performance,the spiral groove aerodynamic gas bearing has a wide range of applications.Mastering the theoretical analysis and optimized design methods of spiral groove aerodynamic gas bearings is of great significance for bearing design and application.This paper conducts static and dynamic characteristic analysis and optimized design of spiral groove aerodynamic radial gas bearings.The main research contents of this paper are as follows:(1)Based on the Reynolds equation for dynamically-pressurized gas lubrication under isothermal conditions and the gas film thickness equation,the basic equations for calculating the static characteristics of spiral groove aerodynamic radial gas bearings are established.The finite difference method is used to solve the equations to obtain the static characteristics such as gas film pressure,bearing capacity,and attitude angle of the spiral groove aerodynamic radial gas bearing.The influence of bearing parameters such as groove length ratio,groove width ratio,groove depth ratio,groove angle,number of grooves,and eccentricity on the bearing carrying performance is analyzed.(2)By introducing dynamic eccentricity and dynamic attitude angle in the complex domain,the basic equations for calculating the dynamic characteristics of spiral groove aerodynamic radial gas bearings are derived under arbitrary small perturbation.The dynamic stiffness and damping coefficients of spiral groove aerodynamic radial gas bearings are solved,and the influence of bearing parameters such as groove length ratio,groove width ratio,groove depth ratio,groove angle,eccentricity,and compression ratio on the dynamic characteristics of spiral groove aerodynamic radial gas bearings is analyzed.(3)With the help of the MATLAB optimization toolbox and the weighted extreme method,an optimization mathematical model for the bearing capacity,stiffness,and stability of spiral groove aerodynamic radial gas bearings is established.By solving the mathematical model,single and multi-objective function optimization designs are performed on spiral groove aerodynamic radial gas bearings,and the optimized results are compared and analyzed.(4)Based on the bearing design parameters optimized for maximum load capacity,the spiral groove aerodynamic radial gas bearing is processed and a test bench is constructed.Experimental research is conducted on the maximum load capacity and the change of bearing attitude angle under large eccentricity of the spiral groove aerodynamic radial gas bearing.Finally,the theoretical calculation results of this article are compared and analyzed with the experimental results to verify the correctness of the calculation method of this article.