Computational assessment of the allowable static contact loading of a roller-slewing bearing׳s case-hardened raceway

Abstract

A computational model for the assessment of the static load capacity of roller-slewing bearings with a case-hardened raceway is presented in this paper. The proposed 3D numerical model considers different influential parameters (arbitrary roller geometry, actual mechanical properties of raceway׳s material, tilted contact between the roller and raceway segment, etc.) on the allowable contact loading between rollers and their raceway. Within this paper, three representative types of roller geometries and their effect on the static load capacity are investigated: a cylindrical roller (ZR), a logarithmical roller (LN) and a partially crowned roller (ZB). For each type of roller, two different criteria are then used to determine the limit contact loading: (i) permanent indentation criterion and (ii) subsurface damage criterion.The results of a comprehensive computational analysis have shown that there are significant differences between each roller type with regards to limit contact load. The other important influencing parameters are the case depth of the raceway and the tilt angle, which mainly depends on the bearing clearance, and the contact loading. The proposed model and results presented here may allow manufacturers to take into account some particularities of large slewing bearings to improve their static load capacity.