Abstract: Addressing the common challenge of microscale gas leakage at sealing interfaces of mining equipment under low vacuum conditions, this study analyzes the failure mechanisms of sprocket seals in vacuum environments. A microscale leakage mathematical model considering interface roughness, material elasticity, and rarefied gas slip flow is developed, revealing the transmission characteristics and nonlinear evolution of gas under vacuum pressure gradients. Using FEA-CFD coupled simulation, the stress distribution, flow field evolution, and leakage path dynamics of the seal are investigated under load disturbances and pressure gradients. The study results show that, at a vacuum level of 5 kPa, a compressive force of 1 000 N, and a roughness of 0.8 μm, the lubricant vapor leakage is 1.62 mL/min, 37.9% lower than that of the conventional structure, indicating a significant performance improvement. Further analysis reveals that material modulus, interface morphology, and vacuum rarefaction effects are decisive factors in determing sealing reliability. The findings not only enhance understanding of gas-solid coupling in vacuum seals but also provide theoretical and engineering guidance for advancing vacuum sealing technology and optimizing vacuum equipment design.

Key words: vacuum sealing, microscale gas flow, slip flow, leakage mechanism, multiphysics coupling