Surface texturing, as a technology capable of markedly enhancing surface tribological properties, has garnered significant attention from researchers worldwide due to its multifaceted benefits, including friction reduction, wear resistance, vibration damping, anti-adhesion, and creep prevention. With the rapid development of our national defense industry, high reliability, efficiency, and lightweight have become design imperatives for aerospace gear transmission systems. Aerospace high-speed gears confront rigorous operating conditions characterized by high temperatures, high rotational speeds, and heavy loads. As core components of aerospace power systems, gears dictate the service life of aerospace equipment; nonetheless, the design of their surface tribological properties remains a weak aspect demanding further enhancement. To leverage surface texturing to improve the service performance of aerospace gear pairs, this study employed a three-dimensional isothermal line contact elastohydrodynamic lubrication (EHL) model to analyze the EHL performance of circular dimple textures with varying geometric parameters on gear pair surfaces at three typical engagement positions: the tooth top, pitch circle, and root. The study predicted the optimal geometric parameters for circular dimples at each engagement point and examined the impact of texture shape on lubrication performance. Numerical calculation results indicated that under specific parameters, surface texturing could increase the local film thickness on gear tooth surfaces, thereby enhancing lubrication performance. The optimal depth-to-diameter ratio for circular textures at three typical meshing positions was identified as 0.06. Meanwhile, the optimal area ratios were found to be smaller at the tooth root and pitch circle, being 5% and 12% respectively, whereas at the tooth top, the optimal area ratio increased to 32%. Additionally, gear pairs with surface texturing exhibited an augmented hydrodynamic pressure effect across their interacting surfaces, resulting in maximum oil film pressures for textured gear pairs that exceeding those of smooth gear pairs. Observations from oil film pressure distribution contour maps further revealed elevated oil film pressures in the regions near the lubricant outlet zones as it flowed through the textured areas. At various meshing points, comparisons were made regarding the lubrication performance imparted by gear surfaces textured with different morphological parameters. It was discovered that at the pitch circle and root of the teeth, circular textures performed the best, followed by rectangular ones, with elliptical textures yielding the least favorable results. Conversely, at the tooth tip location, elliptical parallel textures proved to be most efficacious. The analysis attributed these differences to the influence of the additional hydrodynamic pressure effects, a consequence of the size and shape of the converging wedges formed by the textures, on the elastic deformation of the gear surfaces. This in turn altered the oil film thickness at the contact interfaces. Both circular and rectangular textures possed broader converging wedges, leading to a greater average oil film thickness at the contact surfaces.

The above numerical results complement the missing texture optimization parameters in gear texturing, providing valuable references for enhancing the tribological properties of aeronautical high-speed gears. Furthermore, the research endeavors into micro-texturing design and its tribological characteristics hold significant theoretical significance and practical value for overcoming the technological bottlenecks related to fatigue wear failure of aviation gears under extreme operating conditions.