反转轴间气膜密封振动过程分析

Vibration process analysis of a gas film seal in counter-rotating shafts

对一种双端面反转轴间气膜密封因外界扰动而引起的振动进行了研究,用有限元方法计算了两个端面的气膜刚度和阻尼,分析了瞬态扰动力作用下前密封跑道和主密封环的振动过程,并研究了系统质量、压力等因素对振动的影响。结果表明,系统的自由振动频率主要由前密封跑道质量决定,主密封环质量对自由振动频率影响较小;同一密封跑道质量对应的不同的环道质量对系统的振动收敛时间影响不大;系统的压差越大,所能承受的扰动力越小,越易瞬时振动失稳。该计算结果对气膜密封的动力学响应分析具有一定的指导意义。

The vibration process of a double-faced gas film seal in counter-rotating shafts was studied here.The stiffness and damping of both end faces of the seal were calculated with finite element method.The vibration process of the seal caused by transient force was analyzed.Then,the effects of the system mass and pressure on the vibration of the system was studied.The results showed that the free vibration frequency of the system is mainly dependent on the mass of the seal racetrack,and the effect of the primary seal ring mass on the free vibration frequency could be neglected;the different ratios of the system mass to the same racetrack mass has little influence on the convergent time of the vibration of the system;as the pressure raises,the force that the system can bear becomes smaller and the system is easy to be unstable.The calculation and analysis above was helpful for the dynamic response analysis of a gas film seal in counter-rotating shafts.