Dynamic analysis of deep groove ball bearing with localized defects and misalignment

Abstract

BackgroundOuter ring localized defects and inner ring misalignment are very common failures in bearings, and they are likely to exist at the same time and have complex impacts on bearing performance, especially when the defect is both offset and bias. Currently, there is a lack of a deep groove ball bearing model that can reasonably simulate this situation. MethodsIn this paper, a new time-dependent displacement excitation model based on piecewise function is proposed to analyze the process of ball passing through both offset and bias defects considering inner ring misalignment, and a 5-degree-of-freedom dynamic model is solved to obtain the vibration response. ResultsThe results show that the offset distance and bias angle can significantly change the excitation durations of entering and leaving the defect, further affecting the acceleration impact. In addition, inner ring misalignment can increase or decrease the bearing acceleration root mean square, depending on the direction of misalignment, and these effects are also related to the misalignment magnitude and the defect location. DiscussionThis study presents a feasible solution to model defective bearings with misalignment, and provides a theoretical basis for bearing fault diagnosis and performance prediction.