| The interface leakage of friction pair in key parts of mechanical seal is the most important leakage part in the whole sealing device.Mechanical seal system is a complex component composed of multi field,multi system and multi parts.As one of the most important parts,the normal operation of the friction pair is the key of the whole seal system.The complex working conditions lead to the breaking of the balance condition of the sealing condition of the friction pair.According to the basic principle of stable operation of multi-body and multi-field friction pairs,the dynamic characteristics of the interface of friction pairs are analyzed from a macro point of view to grasp the heat transfer and deformation of friction pairs in the normal operation process of mechanical seal;in view of the similarity between fractal theory and rough surface,fractal theory is introduced into the description of friction pairs,and W-M fractal function is established as the evaluation A means of the end surface morphology of the friction pair provides a model basis for the analysis of the mechanical seal interface.In this paper,the friction pair of contact mechanical seal is taken as the research object,and the whole heat transfer model of the seal ring of the friction pair is established.The friction heat is loaded to the interface of the friction pair as the only heat source through the heat structure coupling calculation.The temperature field distribution of the end face of the friction pair,the deformation of the end face and the influence of the different end face ratio on the heat transfer performance of the end face of the friction pair are obtained by changing the working condition parameters.The results show that the highest temperature and the largest heat flow seal of the seal ring are concentrated near the inner diameter of the friction pair end face;the friction pair material with good thermal conductivity is more conducive to the temperature conduction of the friction pair interface;with the increase of the specific pressure of the sealing medium and spring,the deformation of the friction pair increases gradually,and with the increase of the rotating speed,the deformation of the friction pair decreases.According to the relationship between surface roughness and W-M fractal function,the fractal number and characteristic scale coefficient are changed as influencing factors,which proves the feasibility of using W-M fractal function to evaluate the friction interface.A friction pair model based on W-M fractal function is established to study the dynamic pressure effect of friction pairs with different fractal dimensions.The results show that with the increase of fractal dimension,the pressure between the interface of the friction pair increases with the constant inlet and outlet pressure.Compared with the concave convex position,the convex position bears more pressure,and the concave position stores a certain amount of fluid,which reduces the pressure.When selecting the material of the end face of the friction pair,choose the material with flat surface,which is conducive to the formation of the oil film and the stability of the seal balance. |
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