Film thickness and traction curves of wind turbine gear oils

The film thickness and the traction curves of four fully formulated wind turbine gear oils were measured on a ball-on-disc device. All oils have the same viscosity grade (ISO VG 320) and different formulations: ester, mineral, PAO and mineral+PAMA. Film thickness and traction coefficient results will be presented. The film thickness measurements were compared with predictions using film thickness equations from the literature. •Four wind turbine gear oils were selected.•Film thickness measurements at different temperatures.•Torque loss was measured for a type C40 FZG gears.•Traction coefficient and Stribeck curves.