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基于质量守恒的JFO空化边界条件建立了雷列台阶-环槽机械密封端面润滑理论模型,采用有限单元法求解Reynolds控制方程,获得了端面膜压、密度比与液膜流线分布,分析了其密封机理与性能规律.结果表明:密封环端面内径侧的圆环浅槽和端面中部的圆环深槽组合结构可造成合理的空化现象,达到空化减漏的目的.其中,端面中部的圆环深槽是端面高压侧雷列台阶和端面低压侧圆环浅槽的隔离带,使得端面低压侧压力分布受端面高压侧压力分布的影响极小.密封流体进入低压侧圆环浅槽时,端面间隙突然发散,压力低于该工况温度下的饱和蒸汽压,整个圆环浅槽区液膜空化,达到零泄漏并出现大量的回流现象.外径侧雷列台阶提供良好的动压承载能力,实现了端面的非接触.雷列台阶和环槽织构的组合应用使得该机械密封具有优良的综合性能.
Based on the JFO cavitation boundary conditions of mass conservation, a theoretical model of Rayleigh step-ring groove mechanical seal face lubrication is established. The finite element method is used to solve the Reynolds equation of control, and the surface film pressure, density ratio and liquid film flow line distribution are obtained. Its sealing mechanism and performance law.The results show that the combination of the annular shallow groove on the inner diameter side of the seal ring and the annular deep groove on the middle of the end face can cause a reasonable cavitation phenomenon and achieve the purpose of cavitation and leakage reduction.Among them, The ring deep groove is the isolation zone of the high pressure side thunder column step and the low pressure side annular shallow groove on the end face so that the pressure distribution on the low pressure side of the end face is very little affected by the pressure distribution on the high pressure side of the end face.The sealing fluid enters the low pressure side ring shallow groove , The gap between the end faces suddenly diverges and the pressure is lower than the saturated vapor pressure at the working temperature, and the liquid film in the shallow groove area of the circular ring is cavitated to reach zero leakage and a large amount of reflow phenomenon occurs. Dynamic pressure bearing capacity, to achieve the non-contact end faces.The combination of Rayleigh steps and ring groove texture makes the mechanical seal has excellent overall performance.