Vibration analysis of a deep groove ball bearing with localized and distributed faults subject to waviness based on an improved model under time-varying speed condition

In this paper, a six-degree-of-freedom (6-DOF) comprehensive dynamic model of bearing-pedestal having waviness on its inner race and different sized surface damages has been presented to investigate the vibration response under time-varying speed conditions. It can provide a good solution to further analyze rotor systems with unfixed or elastic-supported pedestals, where vibrations in both horizontal and vertical directions are crucial. A signal processing method for fault feature extraction and enhancement of rolling element bearing in varying speed conditions is proposed. Vibration patterns with different raceway waviness and different sized surface damages are specifically studied. Characteristic frequencies are observed, which can be used for diagnosis of different sized waviness and faults under time-varying speed process. The present study will provide new insights into dynamic behavior of bearing system,