深低温氢气润滑箔片气体动压轴承特性研究

Research on Performances of Deep Hypothermia Hydrogen Gas Foil Bearings

针对实际工程运用中氢气润滑箔片气体动压轴承出现的湍流效应,结合氢气润滑箔片气体动压轴承所处的深低温状态,利用壁面定律修正经典气体雷诺方程,耦合Link-Spring力学模型后求解并获得了以深低温氢气作为润滑介质的箔片气体动压轴承静动态特性;对比箔片气体动压轴承在深低温氢气与其他润滑气体介质时的静态特性,分析偏心率、环境压力、宽径比和名义间隙等参数对箔片气体动压轴承静动态特性的影响.结果表明,相较于常温常压空气和低温高压氮气,以低温高压氢气为润滑介质的箔片气体动压轴承的承载力相对较低,但可通过增大轴承的偏心率、工作环境压力、宽径比、动力黏度和减小轴承的名义间隙等方式增大承载力;轴承的直接动态刚度系数随环境压力的增大而增大,随名义间隙的增大而减小.

Aiming at the turbulence effect of hydrogen gas foil bearings in practical engineering applications,the static and dynamic performances of the gas foil bearings,lubricated by low-temperature hydrogen,are obtained by coupling the Link-Spring model and Reynolds equation,where the Reynolds equation is modified by the law of the wall,combined with deep hypothermia state of hydrogen gas foil bearings.The static performances of the gas foil bearing lubricated by low-temperature hydrogen and other gas media are compared.The effects of eccentricity,ambient pressure,width-diameter ratio,and nominal clearance on the static and dynamic performances of the gas foil bearing are analyzed.The results showed that the load capacity of gas foil bearing in low-temperature and high-pressure hydrogen conditions is relatively low compared with that of atmospheric air and low-temperature and high-pressure nitrogen lubricating conditions.The load capacity can be intensified by increasing the eccentricity,ambient pressure,width-diameter ratio,the dynamic viscosity coefficients,and reducing the nominal clearance.The direct dynamic stiffness coefficients show an upward trend with the increasing ambient pressure and the decreasing nominal clearance.