微机电系统径向气体轴承特性研究

充分考虑气体滑流边界条件的影响,结合硬球分子模型,提出一种可变温度二阶滑流修正Reynolds方程,并运用Newton-Kantorovich法(NKM)分析微机电系统(MEMS)径向气体轴承的特性,结果表明,微气体轴承与传统气体轴承相比,其承载能力有所降低;在大偏心率条件下,随着温度的升高,工作气体粘度及其分子平均自由程增大,使微气体轴承的承载能力进一步降低;针对微旋转机械转速高、长径比小等特点,讨论了转子转速、长径比及温度对径向微气体轴承特性的影响。

Characteristics of Micro Gas Journal Bearing

A new second-order slip flow based on a modified Reynolds equation, which is derived by combining the second-order gas slip boundary conditions and Hard Sphere Molecule model, is proposed. It can be used to investigate the influence of the temperature of the working gas on a thin film lubrication. By applying the new modified Reynolds equation to the model of micro gas bearings and solving it numerically using Newton-Kantorovich Method(NKM), the static performance of the micro gas bearing is investigated. The simulation results show that the load capacity of the micro gas bearing is largely reduced compared to the conventional ones. As the temperature increases, its load capacity increases at lower temperatures and then decreases when the temperature is high. The effects of the rotational velocity and the length to diameter ratio are investigated to account for their influence on the inherent characteristics of the micro gas bearings.