Non-destructive Prognostics for Rolling Bearings by Eddy Current Testing

Abstract

Rolling bearings, which are assembled into various industrial machinery, are regularly replaced after being used for a period of time, even if they have not failed. It is important to predict failure of rolling bearings not only for safe operation of machineries but also for resource conservation. The X-ray diffraction (XRD) is known as an effective method for estimating the remaining useful life (RUL) of rolling bearings. However, it is a destructive approach sometimes requiring cutting bearing rings. Therefore, non-destructive and simple diagnostic method for estimating RUL of rolling bearings using Eddy Current Testing (ECT) has been developed by focusing on the experimental evidence that changes in microstructure of the steel cause changes in the magnetic property. Rolling contact fatigue tests were conducted using several types of rolling bearings, and it was found that the ECT measurement results on raceway surface show a determined behavior with fatigue progress. The tendency of changes did not depend on bearing type, material or heat treatment. Additionally, measurement results by ECT were related to those by XRD. Above experimental results suggest that ECT can be applied to estimate RUL of rolling bearings as a non-destructive and simple method.