端面倾斜对粗糙表面机械密封性能的影响

针对航空泵用机械密封实际操作条件,考虑粗糙表面弹塑性接触,基于质量守恒的JFO(Jakobsson-Floberg-Olsson)空化理论建立了倾斜粗糙端面机械密封环的液体润滑和混合润滑计算模型;采用有限单元法求解PC(Patir and Cheng)平均Reynolds方程,获得端面液膜的压力分布;对比研究了在不同的密封压力、中心膜厚和转速条件下,端面倾斜角对粗糙表面和光滑表面机械密封性能参数的影响规律.结果表明:随着倾斜角增大,端面的承载力增大,摩擦力先减小而后增大,泄漏率增大;当端面倾斜角较小时,粗糙表面机械密封性能优于光滑表面机械密封性能.

Mechanical Seal Performance of Rough Surface Influenced by Tilt

According to the actual operating conditions of mechanical seal used in aviation pumps, a theoretical model of hydrodynamic and mixed lubrication conditions was developed for mechanical seal with rough and tilted surfaces. The model considered elastic plastic contact between rough surfaces, and the Jakobsson Floberg Olsson (JFO) cavitation boundary condition of mass conservation in lubrication film. Finite element method was used to solve the Patir and Cheng average Reynolds equation, and the fluid film pressure distribution between seal surfaces was obtained. The influence of the non dimensional tilt angle on the seal performance was analyzed under different values of sealed pressure, central film thickness and rotational speed. A performance comparison between rough and smooth surfaces was conducted with a mechanical seal. The results showed that with increasing tilt angle, the load carrying capacity and the leakage rate increased, the friction force decreased firstly and then increased. The mechanical seal with rough surfaces had better performance than that with smooth surfaces when one of seal surfaces had a small tilt angle.