中压机械密封端面接触状态和应力研究

Study on Contact State and Pressure of Medium Pressure Mechanical Seals

密封端面间的接触状态和应力分布影响着密封端面的磨损和变形,对机械密封的寿命和密封性能尤其重要。为研究密封端面间的接触状态和应力分布,建立机械密封动环、静环和静环座完整准确的双接触对有限元模型,分析工作压力、静环高径比(静环高度和外径的比值)、载荷系数和静环辅助O形圈内径比(O形圈的内径与机械密封平衡直径的比值)等参数对接触状态和应力分布的影响规律,得到密封端面间的接触状态和应力分布。结果表明:工作压力较低时端面接触应力分布均匀,端面全接触;但压力较高时接触应力分布可能不均匀,且工作压力越高分布均匀性越差,端面接触面积越小;静环高径比、载荷系数和静环辅助O形圈内径比等参数的增加会使接触应力分布更均匀,接触面积增加,端面最大接触应力减小,有利于密封的运转。

The contact state and stress between the mechanical seal face affect the wear and deformation of seal surface, and they are very important for the mechanical seal＇ s life and sealing performance. To study the contact state and stress distribution of the mechanical seal face, the complete and accurate finite element model was established for two contact pairs of rotator ring, stator ring and stator ring seat. The influence of working pressure, stator ring height diameter ratio （the ratio of stator ring height and outer diameter）, load factor, and O-ring position diameter ratio （the ratio of O-ring inside diameter and the balance diameter of mechanical seal） on the contact state and stress was analyzed, and the face contact state and stress distribution were obtained. The results show that the contact stress distribution is uniform at low work pressure and the face is full contact, while the contact stress distribution may not be uniform at high work pressure. And the higher the working pressure is, the worse the distribution uniformity of contact press, and the less the contact area becomes. The increase of stator ring height diameter ratio, load factor, and O-ring position diameter ratio will make the contact stress distribution more uniform, the contact area larger, and the maximum contact stress less, which is in favor of seal operation.