Calculating method of radial stiffness of cylindrical roller bearings

Most of the previous researches about roller bearing stiffness assumed the solid contact stiffness of roller and raceways as the overall roller bearing stiffness. However, oil-film stiffness due to the relative motions between roller and raceways is also an important source of the roller bearing stiffness. In this paper, the load distribution and the elastic deformation of cylindrical roller bearing were analyzed. A formula to calculate the static stiffness of roller bearing was derived from Hertz contact theory, and then influences of oil film thickness were studied with introducing EHL theory and Dowson-Higginson formula. A numerical expression for calculating overall radial stiffness of roller bearing was established. The new calculating method of cylindrical roller bearing stiffness was proved of high accuracy through a practical example.