Dynamic loading effects on the fatigue mechanism, and crack propagation in rolling element bearings using density estimation: a signal processing analysis

Bearings play a crucial role in supporting the rotating shaft and withstanding different kinds of loading. Thus, failure in the bearing not only halts shaft operation but also affects machine functioning as a whole. To better understand fatigue behaviour and increase machinery reliability, crack propagation in bearings is a critical failure mechanism. To examine the effects of fatigue loading on crack initiation and propagation, an axial groove defect was seeded on the outer race of a tapered roller bearing. It was observed from the experimentation that as the crack initiates and propagates, the density level was also increasing. Hence, a new technique, based on the deviation in the density estimation of the measured vibration data, is suggested, which demonstrates an increasing trend with a broader tail and an increase in the value of density estimation and can be related to crack initiation and propagation. The results showed that loading causes the crack to propagate faster in less time and affects the remaining useful life drastically. The proposed method provides an efficient and reliable tool for early fault detection, condition monitoring and predictive maintenance of rolling element bearings.