Dynamic analysis of spindle-bearing system considering bearing wear evolution

Bearing wear is an inevitable and a slowly evolving process. It affects the dynamic response of spindle-bearing systems by changing contact status between ball elements and raceways, causing the machining accuracy of spindle-bearing system to be gradually decreased. The effects of bearing wear evolution on dynamic characteristics of spindle-bearing system are worthy of further investigation, which can provide valuable insights into the wear-induced quantitative diagnosis in spindle-bearing system. In current work, a comprehensive mechanical–thermal–wear coupled model of the spindle-bearing system is proposed to analyze dynamic characteristics of spindle-bearing system considering bearing wear evolution effects. The bearing wear, temperature change and dynamic response under different preload displacements, working loads and spindle speeds conditions are discussed. The results show that both bearing preload and working load significantly affect bearing wear. The magnitude of temperature change of the spindle-bearing system decreases at first and then nearly keeps constant with bearing wear. Bearing wear changes the dominant frequency of the spindle-bearing system and leads to more abundant dynamic response frequency compared with no wear condition. Low- and medium-speed conditions are more valuable than high-speed condition for identifying bearing wear severity. The results of this study could be of significance in decision-making processes that would require identification and quantitative diagnosis of bearing wear evolution and system lifetime prediction.