Berechnung der Massstabilität von Wälziagerbauteilen

Bearings are precision machine elements and even minute alterations in the size of the individual components can change the internal clearance and the mounting conditions for the bearing. No hardened steel is completely dimensionally stable, meaning that the microstructure may undergo changes on exposure the operating conditions (time, temperature and stress). Such changes induce volume changes of the material and thereby size changes of the individual bearing components. If the material is also exposed to static structural stresses like the hoop stresses induced in bearing inner and outer rings when interference fitted, respectively, on a shaft or in a housing, the dimensional change may be magnified. This paper describes the mechanisms behind these thermally and mechanically activated dimensional change mechanisms and presents a model for the calculation of dimensional change under actual bearing operating conditions. The model is used, in combination with other modelling tools, to help optimizing the selection of bearings for any given application condition. The capabilities of the modelling tool will be demonstrated, based on selected application examples.