Analysis of the Tribological Behavior and Meshing Stiffness of Microcavity Gear Pairs under Starved Lubrication and Heavy Load Conditions

This study explores the tribological performance and meshing stiffness of microcavity spur gear pairs operating under starved lubrication and heavy load conditions. Sliding–rolling tests and analytical modeling were performed on three gear surface types: Type A (non-textured), Type B (microcavities with 67 μm diameter, 54 μm depth, and 654 μm spacing), and Type C (microcavities with 128 μm diameter, 13 μm depth, and 599 μm spacing). Compared to the non-textured Type A, Type B reduced the friction coefficient by 16.8% (initial value: 25.9%) and decreased wear depth, as indicated by a 23.5% reduction in surface roughness (Rz). The time-varying meshing stiffness (TVMS) model further showed that Type B mitigated stiffness degradation (≤0.25%) by lowering friction, whereas Type C increased both friction and contact area, leading to greater stiffness loss (up to 0.5%). These results suggest that an appropriately designed microcavity texture can enhance tribological behavior while maintaining meshing stiffness, providing valuable insights for improving gear performance under extreme operating conditions.