Analysis of influencing factors of sealing face performance of mechanical seal coating

doi:10.11949/j.issn.0438-1157.20171544

Abstract

Abstract:

The application of sealing ring for mechanical coating, which combines the characteristics of wearresistant coating with the characteristics of the toughness base material, depends on experience. There is a lack of research on its performance. A thermal structural coupling model consisting of rotating seal ring, stationary seal ring and stationary ring seat was established by using ANSYS software. It considers the influence of the coating surface deformation, the liquid film reverse pressure and the temperature between the sealing rings. The correctness of the analytical model is validated by the experiment. The influence of coating structure and material on the product of seal face pressure and maximum velocity ((P_bV)_max), the seal face in the highest end temperature (T_max), coatings on the surface of the maximum tensile stress (σ_max), maximum shear stress of the main interface (τ_max), the interface maximum side effect of shear stress (σ_cmax) and the maximum tensile stress (τ_cmax) was analyzed, and the coating structure and material were determined. The results show that the coating thickness, the coating and the substrate of the thermal expansion coefficient and elastic modulus ratio mainly affect the coating surface of the maximum tensile stress. For the coating surface design the thermal expansion coefficient of coating and substrate should be more than 0.5, the spraying angle should be 15°-30°, the elastic modulus ratio should be below 2.5, and the coating thickness should be 0.4-0.6 mm.

Key words: mechanical seal, coating surface, stress

摘要：

机械密封覆层密封环能够综合利用耐磨覆层与韧性基体材料的优良特性，但其应用主要依靠经验，缺乏针对其性能的研究。利用ANSYS软件建立釜用机械密封动环、静环和静环座组成的热-结构耦合模型，综合考虑覆层端面变形、液膜反压和密封环温度之间的相互作用，并试验验证了分析模型的正确性。分析覆层结构和材料组合对密封端面最大端面比压与速度的乘积（P_bV）_max、最高端面温度T_max，覆层表面最大拉应力σ_max、主界面最大切应力τ_max、侧界面最大切应力σ_cmax和最大法向拉应力τ_cmax的影响，并确定最佳的覆层结构和材料组合。分析结果表明：覆层厚度、覆层与基体的热膨胀系数比和弹性模量比的变化主要影响覆层表面最大拉应力；覆层端面设计中，覆层厚度取值宜在0.4～0.6 mm，喷涂角度宜取15°～30°，覆层与基体的热膨胀系数比宜在0.5以上，弹性模量比宜在2.5以下。

关键词: 机械密封, 覆层端面, 应力

CLC Number:

TB301

LI Shuangxi, SUN Xiandong, ZHANG Peng. Analysis of influencing factors of sealing face performance of mechanical seal coating[J]. CIESC Journal, 2018, 69(7): 3181-3189.

李双喜, 孙宪栋, 张鹏. 机械密封覆层密封环端面性能分析[J]. 化工学报, 2018, 69(7): 3181-3189.

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