Increasing the lifetime of roller bearings by using precision deep rolling

Increasing the lifetime of roller bearings by using precision deep rolling

Kategorien Konferenz (reviewed)
Jahr 2015
Autoren Denkena, B., Grove, T., Maiß, O., Neubauer, T., Poll, G., Dreier, S.:
Veröffentlicht in euspen´s 15th International Conference & Exhibition, 01. - 05.06.2015, Leuven, Belgien, S. 373 - 374.

It is a well-known fact that residual stresses can improve the lifetime of machined parts. Especially the lifetime of roller bearings is mainly affected by the residual stress state. Conventional machining processes like grinding and honing do not induce high compressive residual stresses in depth of 150 µm to 200 µm to affect the lifetime of roller bearings. Using a defined cutting edge in a hard turning process and applying a subsequent deep rolling procedure, the residual stresses can be shifted to a highly compressive state in great depth. However, due to grinding and honing roller bearings can be machined in a high quality of surface roughness, shape and geometry. In hard turning experiments it could be shown that a comparable part quality to grinding can be reached, if a suitable clamping technique is applied. Within the literature there is no knowledge about the part quality after deep rolling. According to the theory, deep rolling does not affect the shape of the machined parts. It smooths the surface, increases the hardness and induces compressive residual stresses. In deep rolling of roller bearings of the type NU206 C3 high compressive stresses in the subsurface region cause unacceptable shape changes. Within this paper, the shape deviation due to residual stresses is investigated and the main effects on residual stress state and shape deviation are identified. A procedure is introduced how to identify the optimal deep rolling process with respect to the roller bearings lifetime and the surface roughness-, shape- and geometry quality.