Wear of rolling element bearings

Bearing wear prognosis requires effective modelling and monitoring of rolling contact. Rolling contact wear is responsible for the damages initiating on and beneath the contacting surfaces. It is commonly observed in the experimental studies that rolling contact wear follows specific stages of initiation (i.e. debris, dentation, inclusions) and propagation (i.e. dents, micro-cracks, pits, spalls) over the lifetime. The initiation and propagation stages are functions of load induced stresses, material characteristics and operating conditions. Thus, different physical mechanisms are represented in the evolution of rolling contact wear. Different monitoring techniques have limited physical capability. Therefore, the purpose of this paper is to describe the evolution of rolling contact wear, which is measured using different possible monitoring techniques. Dynamic response, stress wave, and debris particles are the main outcomes for each stage of wear progress. The paper utilises a proposed five-stage model of rolling contact wear progress in order to explore the measured outcome of contact mechanics: Running-in, steady-state, defect initiation (dentations, pits, inclusions), defect propagation (extended pits, propagated cracks), damage growth (spalls). The paper is relevant in exploring the possible measurement techniques for the prognosis of the development of rolling contact wear.