一、前言 随着宇航事业的发展,高能液体推进剂的应用,石墨材料作为涡轮泵的动密封元件已日益普遍。液氧密封是石墨密封材料的应用领域之一。液氧和其它超低温流体在润滑系统中将引起一些特殊问题。 液氧粘度很低,在—18.3℃时液氧的粘度只有普通润滑剂粘度的四百分之一,其润滑性能较差。同时液氧是强氧化剂,对于转动密封来说,尽可能减少泄漏是非常重要 I. Introduction With the development of aerospace industry, the application of high-energy liquid propellants, graphite materials as the dynamic sealing components of turbo pumps has become increasingly common. Liquid oxygen seal is one of the applications of graphite seal material. Liquid oxygen and other cryogenic fluids in the lubrication system will cause some special problems. Liquid oxygen viscosity is very low, the viscosity of liquid oxygen at -18.3 ℃ is only one fourth of the viscosity of ordinary lubricants, its lubricating properties are poor. While liquid oxygen is a strong oxidizer, it is important to minimize leakage as far as rotary seals are concerned