Preload and stiffness
Due to the large number of cylindrical rollers in each of the rows, with line contact between them and the raceways, there is a minimal amount of elastic deformation in the bearing under load from any direction.
To provide maximum stiffness the rollers are calibrated during assembly so that a preload is achieved in each row once mounting is complete. Appropriate preload extends bearing service life, improves rigidity and running accuracy, while reducing noise levels.
As a result of the closely controlled preload, stiffness in any direction can be considered constant.
In cases where a heavy axial load acts on an axial-radial cylindrical roller bearing, the loaded roller set can deflect and reduce the preload on the second thrust roller set. In severe cases, the second thrust roller set can become completely unloaded, which can cause the rollers to skid and damage the raceways or subject the cage to impermissible stresses. For additional information, contact the SKF application engineering service.