Article on raceway crowning of roller bearings

Contact pressure distribution in bearings is determined by micro-geometry of the contact surfaces, related axial and radial loads and by misalignment between shaft and housing, while especially cylindrical and tapered roller bearings are very sensitive for misalignment which can be caused by both initial manufacturing deviations or by elastic deflection due to operation conditions. In most applications, loads and misalignment can hardly be influenced why optimization of micro-geometry is very important for reaching proper contact pattern without any critical pressure peaks and thus providing sufficient lifetime of the bearing.

By means of finite-elements-method, contact pattern due to operational loads and deflections can be assessed which allows discussion of different concepts for micro-geometry. Subsequently both optimized geometry can be determined and influence of tolerances can be estimated. Based on that, detailed specifications for micro-geometry can be developed for each particular bearing and application.

As optimization based on sophisticated simulation of each particular case is very expensive, in a second step, a simplified method has been developed which allows transferring of results from one case to a family of similar applications. Subsequently, micro-geometry of roller bearings can be controlled by reasonable effort and precision which is sufficient for a broad spectrum of applications.