Flow field study and lubrication performance optimization of gearbox based on the SPH method

Journal article, 2025

Gearboxes play a pivotal role in the transmission systems of rail vehicles, directly influencing power efficiency, operational reliability, and safety. Inadequate lubrication within these systems can result in excessive heat generation, gear wear, and compromised performance. While experimental investigations have provided insights into lubrication dynamics, they are often constrained by high costs and limited observational precision. To address these limitations, a smoothed particle hydrodynamics (SPH) approach is employed to simulate the internal flow field and optimize the lubrication performance of a rail vehicle gearbox. In the investigation, the effects of rotational speed, oil volume, and temperature on lubrication characteristics are systematically evaluated through comprehensive numerical simulations. Parameter optimization is achieved via Taguchi's method supplemented by analysis of the signal-to-noise ratio and analysis of variance (ANOVA) to identify the optimal operating conditions. The results indicate that increasing the rotational speed, oil immersion depth, and temperature can enhance the lubricant distribution uniformity. Specifically, under the optimal conditions of 4000 rpm, 3.0 h oil immersion depth, and 100 degrees C, the oil volumes in the gear meshing zone and the two bearing regions increase by 183%, 50.8%, and 11.5%, respectively, compared with those of the baseline values. Overall, this work provides a novel integration of SPH modelling with Taguchi optimization techniques, significantly contributing to the enhancement of gearbox lubrication performance. The findings offer practical guidance for improving the reliability of rail vehicle transmission systems and extending the applicability of the proposed methodology to other complex mechanical systems.