Power Loss and Axial Load Carrying Capacity of Radial Cylindrical Roller Bearings

摘要

The application of cylindrical roller bearings (CRB) is widespread in mechanical engineering. CRB can carry comparatively high loads and are usable in high speed ranges. These bearings have been proven to be variably applicable and economic. With lipped inner and outer rings CRB permit the transmission of axial loads in addition to radial loads. The axial load is induced on the lip of the inner or the outer ring and transferred by the roller end face contacts to the opposing lip. In comparison to an only radially loaded bearing, there are additional friction losses in the contact between the lip and the roller ends as a result of sliding. The limiting factors for the permissible axial load are high temperatures, which can cause smearing and seizing, lip fracture, fatigue failure and wear. In consequence of the axial loading, the stresses in the contact between the roller and the raceway rise and the fatigue durability of the bearing is reduced. At high speeds the permissible thrust load is dominantly limited by high temperatures. At low speeds the limiting factors are lip fracture and wear. Within the examination an extensive test program with different bearing geometries is carried out. Thereby the decisive measure is the friction torque of the bearings. The friction torque of a thrust loaded radial cylindrical roller bearing is mainly dependent on the parameters speed, load, size and design of the bearing. An analytical simulation model, which has been developed at the institute, allows calculating the lubrication conditions, the stresses within the lip - roller contact and the axial load dependent friction torque. The intention of the study is to enlarge the application range of radial cylindrical roller bearings by means of a more precise determination of the thrust load capacity and to allow more economic designs.