基于逾渗理论的机械密封界面静态泄漏预测方法

发布时间：2018-04-03 18:08

本文选题：机械密封　切入点：逾渗理论　出处：《摩擦学学报》2017年06期

【摘要】：针对现有机械密封泄漏机理研究存在的不足,利用Hertz理论研究机械密封界面接触力学问题,揭示了孔隙率随端面形貌、端面载荷等参数的变化规律;基于逾渗理论,探讨了不同网格层数下密封界面的逾渗阈值与孔隙率的关系,建立了密封界面泄漏通道模型,以及泄漏率与端面形貌参数关系表达式;研制了机械密封静态泄漏测试装置,测试了6组不同端面形貌试件在一定介质压力下的泄漏率.结果表明:密封界面的初始孔隙率?0随着分形维数D的增大而增大;端面比压pc增大,孔隙率?减小,并随着D的增大和尺度系数G的减小,?快速减小,直至填实.在端面比压作用下,密封界面的孔隙率均大于0.593,密封界面泄漏通道可以简化为单层网格逾渗模型.密封环的表面越粗糙,其密封界面的孔隙率越大,而由孔隙连通形成的泄漏微通道孔喉尺寸就越大,致使密封界面的泄漏率越大;泄漏率理论预测值与试验结果具有良好的吻合度,验证了本文泄漏预测方法的合理性.
[Abstract]:In view of the shortcomings of the existing research on the leakage mechanism of mechanical seal, the contact mechanics of mechanical seal interface is studied by using Hertz theory, and the variation law of porosity with the parameters such as end surface morphology, end surface load and so on is revealed, based on percolation theory,The relationship between the percolation threshold and porosity of sealing interface under different mesh layers is discussed, the leakage channel model of sealing interface and the expression of leakage rate and the relationship between leakage rate and surface morphology parameters are established, and the static leakage testing device of mechanical seal is developed.The leakage rate of 6 groups of specimens with different end surfaces under certain pressure was measured.The results show that the initial porosity of the sealing interface increases with the increase of fractal dimension D, and the specific pressure of the end face increases with the increase of the porosity.With the increase of D and the decrease of scale coefficient G?Reduce quickly until it is filled.Under the specific pressure of the end face, the porosity of the sealing interface is greater than 0.593.The leakage channel of the sealing interface can be simplified as a single-layer mesh percolation model.The rougher the surface of the seal ring, the greater the porosity of the sealing interface, and the larger the pore throat size of the leakage microchannel formed by the connection of the pores, the greater the leakage rate of the sealing interface.The theoretical prediction of leakage rate is in good agreement with the experimental results, which verifies the rationality of the proposed method.
【作者单位】：南京林业大学机械电子工程学院;
【基金】：国家自然科学基金项目(51375245,51505230)资助~~
【分类号】：TH136

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