Analysis of the sealing performance and influencing factors of stepped spiral groove seals for hot oil pumps

Abstract This study numerically investigates the thermohydrodynamic behaviour of non-contact mechanical seals operating under low-to-medium rotational speeds and high-temperature fluid conditions. To address the performance limitations of conventional groove designs in non-isothermal regimes, a Stepped Spiral-T Hybrid Groove configuration is proposed and compared with classical Spiral Groove and Deep-Shallow Groove seals. A three-dimensional model is established, and parametric analyses are conducted to investigate the effects of spiral angle, groove width ratio, and groove depth. Results show that the SSTHG significantly lowers liquid-film temperature through enhanced convective heat dissipation while maintaining controlled leakage. In addition, the SSTHG exhibits moderated pressure peaks, improved load-carrying capacity, and reduced friction relative to the SG and DASG designs, demonstrating superior performance under demanding thermal-viscous conditions.