多级斯特封的密封性能分析  

Sealing performance analysis of multi-stage step seal

作　　者：孙英杰 孙江宏[1] SUN Yingjie;SUN Jianghong(Mechanical Electrical Engineering School,Beijing Information Science&Technology University,Beijing 100192,China)

机构地区：[1]北京信息科技大学机电工程学院,北京100192

出　　处：《北京信息科技大学学报（自然科学版）》2024年第4期25-32,共8页Journal of Beijing Information Science and Technology University

基　　金：2019年产业技术基础公共服务平台项目(0714EMTC000898)。

摘　　要：为研究背压影响下的多级斯特封密封性能转变规律,以两级斯特封为例,建立二维轴对称模型,从宏观结构力学角度研究背压对密封性能的影响;考虑粗糙度与空化效应,搭建流固耦合的混合弹流润滑模型,从密封机理角度进一步分析背压产生的原因。实验结果表明:在宏观上,随着背压值增加第一级斯特封接触长度减少且逐渐失去密封效果,接触压力向唇口集中且峰值升高,易疲劳磨损;第二级斯特封的O形圈将压力有效传递至密封环,使接触压力增加且压力峰值外移,摩擦阻力增加。在密封机理上,第一级斯特封的介质外泄、第二级斯特封的介质回流和两级斯特封的净泄漏量差促使背压形成;背压造成内外行程总摩擦力不稳定,设备运行不畅且难以控制。In order to study the transformation law of sealing performance under the influence of back pressure,a two-dimensional axisymmetric model was established by taking the two-stage step seal as an example.The influence of back pressure on sealing performance from the perspective of macroscopic structural mechanics was studied.Considering the roughness and cavitation effects,a fluid-solid coupling mixed elastohydrodynamic lubrication model was built,and the cause of back pressure was further analyzed from the perspective of the sealing mechanism.The experimental results show that at the macro level,as back pressure increases,the contact length of the first-stage step seal decreases and gradually loses its sealing effect,and the contact pressure concentrates on the lip,increasing its peak value and making it more vulnerable to fatigue and wear.The O-ring of the second-stage step seal transfers the pressure to the sealing ring effectively,so that the contact pressure increases and the pressure peak moves outward,leading to increased friction resistance.In terms of the sealing mechanism,the medium leakage of the first-stage step seal,the medium backflow of the second-stage step seal,and the net leakage difference of the two stages of step seal promote the formation of back pressure.Back pressure causes an unstable total friction force between instroke and outstroke,which makes the equipment unable to run smoothly and difficult to control.

关 键 词：斯特封 多级密封结构 结构力学 密封机理 

分 类 号：TB42[一般工业技术]