Effects of Sand and Dust Particles on Tooth Surface Wear in Wind Turbine Gears

Abstract. Sand and dust particles entering gear meshing interfaces induce abrasive wear, yet whether frictional responses reflect particle-size-dependent wear severity remains unclear. Wear tests on 18CrNiMo7-6 steel compared particle-free contact with three particle-size ranges (0–30μm, 30–60μm, and 60–100 μm). Friction coefficients and wear volumes were measured, and worn surfaces were characterized using three-dimensional topography, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). Experimentally determined wear coefficients were incorporated into a dynamic Archard model to predict tooth surface wear distributions. Compared with the particle-free group, the mean friction coefficient and wear volume increased by 33.3–70.1% and 35.9–86.8%, respectively. From 0–30 to 60–100 μm, the mean friction coefficient increased by 27.6%, whereas wear volume decreased by 27.2%. The finer particles exhibited pronounced grooving and lateral wear-track expansion, while coarser particles showed greater wear debris accumulation and residual Si and O. Under identical dynamic loading and sliding conditions, predicted wear was minimal near the pitch point. High-wear regions occurred on the approach side of the driving gear and recess side of the driven gear, and wear peaks did not coincide with contact pressure peaks. These findings support gear wear risk assessment, wear-resistant design, and service reliability in sand- and dust-laden environments.