Estimation of the rated viscosity ν1
Green shading shows the area where ndm ≤ 10,000 [mm/min]. At these lower ndm values, AW or EP additives are needed to reduce wear.
Orange shading shows the area where ndm ≥ 500,000 [mm/min] for up to 200 mm bearing mean diameter, and ndm ≥ 400,000 [mm/min] for larger bearing mean diameters. At these higher ndm values, operating temperature must be given more attention. Certain bearing types, such as spherical roller bearings, tapered roller bearings and spherical roller thrust bearings, normally have a higher operating temperature than others, such as deep groove ball bearings and cylindrical roller bearings, under comparable operating conditions.
