不同润滑状态下表面粗糙度对人字槽密封性能的影响

摘要

为研究端面形貌对液膜密封密封性能的影响,在人字槽液膜密封端面结构的基础上,建立考虑密封表面粗糙度的数学模型,采用端面形貌表征值(微凸体周向与径向的长度比)和表面粗糙度标准差(综合表面粗糙度的均方根偏差)表征粗糙参数,分析不同润滑状态下表面粗糙度参数对人字槽密封性能的影响.计算结果表明:在混合摩擦状态时,随着端面形貌表征值的增加,摩擦因数和泄漏量逐渐减小,液膜承载能力变大;随着表面粗糙度标准差的增加,摩擦因数和泄漏量变大,液膜承载能力下降;在全液膜密封状态时,随着端面形貌表征值的增加,摩擦因数不变,泄漏量减小,液膜刚度先增大后略为减小;随着表面粗糙度标准差的增加,摩擦因数不变,泄漏量和液膜刚度变大.%In order to study the effect of different groove micro-structures of sealing end face on the sealing performance of liquid film seal,a mathematical model considering the surface roughness was established based on the herringbone groove liquid film seal end structure.The roughness parameters were characterized by the topographic characterization (the ratio of the ratio of the involute to the radial direction) and the standard deviation of the surface roughness (the mean square deviation of the integrated surface roughness).The influence of surface roughness parameters on sealing performance of herringbone groove under different lubrication conditions was analyzed.The results show that in a mixed friction state the friction coefficient and the leakage show decreasing tendency,and the bearing capacity of the liquid film is increased with the increase of surface topography.With the increase of standard deviation of surface roughness,the bearing capacity of liquid film is decreased and the friction coefficient and the leakage are increased.In a liquid film seal state,with the increase of surface topography,the friction coefficient no longer changes,the leakage is decreased,the stiffness of liquid film seal is increased slightly and then decreased.With the increase of the standard deviation of the surface roughness,the friction coefficient does not change,the leakage and the film stiffness are increased.