Patent Document ID: 9074970
Application ID: 14009975
Patent Flag: 1

Claim One:
1. A method for determining a fatigue limit for rolling contact initiated fatigue of a rolling bearing, the method comprising: running a rolling bearing, having a plurality of rolling elements arranged between an outer and an inner ring, wherein the rolling bearing is exerted to a load which generates sub-surface transformations in a rolling element contact zone of the outer or inner ring, and identifying a set of sub-surface transformations in the contact zone along a raceway portion of the rolling bearing, and measuring, for each sub-surface transformation in the raceway portion, a position parameter value representative of sub-surface depth and a stress parameter value representative of contact stress in the contact zone, wherein the method further comprises: generating a data set of sub-surface transformations comprising the position parameter values in relation to the stress parameter values for each sub-surface transformation, determining a fatigue parameter value representative of a predicted fatigue limit for the rolling bearing based on the generated data set of sub-surface transformations, determining at least one shear stress level parameter value representative of shear stress in the contact zone, wherein the shear stress level parameter value depends on contact zone depth and exerted contact stress, and comparing the at least one shear stress level parameter value with the data set of sub-surface transformations.