Patent EP-2495466-A1 (EP)
Inventor: FRANK HUBERTUS
IPC: C21D9/40
Filed: 2011-12-22
Abstract: The rolling element arrangement comprises a ball-, cylindrical roller-, barrel roller-, or tapered roller-shaped rolling element (2), a ball rolling element raceway system (1), and a roller/ball combination of the raceway system for the purpose of two rolling bearing rings mounted to each other and ring segments or segmented rings mounted to each other. A rolling element raceway is hardened: along its ring shape in contact area between the rolling element and a rolling bearing ring (3, 4); and by induction- or inductive hardening methods. The rolling element arrangement comprises a ball-, cylindrical roller-, barrel roller-, or tapered roller-shaped rolling element (2), a ball rolling element raceway system (1), and a roller/ball combination of the raceway system for the purpose of two rolling bearing rings mounted to each other and ring segments or segmented rings mounted to each other. A rolling element raceway is hardened: along its ring shape in contact area between the rolling element and a rolling bearing ring (3, 4); and by induction- or inductive hardening methods. An overlap region and an end of the hardened rolling element raceway are given at the beginning. The overlap region extends itself along the rolling element raceway, and has a region of lower hardness than a hardness slip-region surrounding the overlap region. The hardness slip-region is inclined or tilted, and non-linearly extends through the overlap region. An initial region and an end region of the hardened region cover overlie or overlap along a raceway normal. The hardness slip-region or the region of the lower hardness: is inclined at a certain angle of 45[deg] with respect to raceway normal; and extends toward an imaginary connection line between upper and lower overlap regions, where an actual course of the hardness slip-region is partially formed in a free-, a curved- and/or an arc-shaped manner and contains a straight section. The region of lower hardness extends through the overlap region in track- or band-shaped manner. The region of lower hardness is completely or partially reworked or relief-grinded. A relief grinding-region and the region of lower hardness or the hardness slip-region are closely adjacent to each other and/or completely or partially overlapped or superimposed along the raceway normal. The overlap region with the region of lower hardness is given in each raceway of the rolling element arrangement. An outlet region of hardness zones is inclined in the overlap region at the certain angle of greater than 5[deg] and smaller than 85[deg] with respect to the normal raceway. The rolling element overrunning the relief grinding-region is supported for the main hardened region or the hardness zone and is carried by the hardness zone. A hardening depth of the hardened region or the hardness zone is less than 10 mm. The track- or band-shaped region of the lower hardness is less than 50 mm. The rolling bearing ring consists of heat-treated steel or a rolling bearing steel material such as semiprecious steel material as well as X20Cr13. The hardened regions have a Rockwell hardness of 48-65 HRC. The region of the lower hardness has a Rockwell hardness of less than 48 HRC, or a core hardness of a base material.