静压止推气浮轴承动特性的微扰动法研究

为了实现对静压气浮轴承的动特性进行研究，提出并设计了一种具有可变截面积均压槽的静压气浮轴承，结合气浮轴承的力学振动模型采用微扰动法建立了气浮轴承动态控制方程，运用有限差分法对气浮轴承动态控制方程进行了数值求解，得到了气浮轴承的动态刚度和阻尼。计算结果表明：当振动较小时静压止推气浮轴承的动态刚度值与静态刚度值相当，在气膜间隙为5.5 μm左右时，气浮轴承的动、静刚度均达到最佳值；在同一供气压力下，随着气浮轴承气膜间隙的增大，其动阻尼呈非线性减小，气膜间隙对气浮轴承动阻尼系数的影响较大。

Research on Dynamic Characteristics of Aerostatic Thrust Bearings Based on Perturbation Method

An aerostatic thrust bearing with pressure-equalizing groove with variable sectional area is designed to research the dynamic characteristics of aerostatic thrust bearing. Based on the mechanical vibration model of gas bearings, the dynamic control equations of gas bearings is established by using perturbation method, and the dynamic control equations are sovled to obtain the dynamic stiffness and damping of gas bearings by the finite difference method. The results show that the dynamic and static stiffness values of aerostatic thrust bearings are equal when the vibration is small, and the dynamic and static stiffnesses of gas bearings reach the optimum value when the gas film thickness is about 5.5 μm; the dynamic damping decreases nonlinearly with the increase in gas film thickness at the same air supply pressure, and the gas film thickness greatly affects the dynamic damping coefficients of air bearings.