考虑三维运动和相对滑动的滚动球轴承局部表面损伤动力学建模研究

Dynamic Modeling of Rolling Ball Bearing with Localized Surface Defects Considering Three Dimensional Motions and Relative Slippage

滚动体通过局部表面损伤时轴承的运动参数及动力学响应是轴承疲劳损伤分析和故障诊断的有效输入和重要依据。基于GUPTA轴承模型构建具有局部表面损伤的滚动球轴承的完整动力学模型。该模型中每个轴承元件(滚球、内圈及外圈)具有6个自由度,并且考虑了元件之间的相对滑动和润滑牵引特性。在对局部表面损伤进行建模时,完整考虑了损伤出现后由于材料缺失而引入的额外间隙,以及损伤对赫兹接触刚度及接触载荷作用方向的影响。研究滚球在通过局部表面损伤时轴承的加速度与滚球/损伤之间冲击力的对应关系,以及轴承转速和损伤宽度对轴承振动响应的影响规律。仿真结果表明,由于考虑了相对滑动和滚球/损伤之间冲击力的影响,本模型能够对具有局部表面损伤的球轴承进行更为合理的动力学特性分析,可为滚动球轴承的疲劳损伤分析和故障定量诊断提供一定的理论依据。

Vibration responses and kinematic parameters when a ball rolls over and impacts with a localized surface defect can provide efficient inputs and theoretical foundations for bearing fatigue analysis and fault diagnosis. A dynamic model for rolling ball bearings with localized defects is proposed based on GUPTA model. In this model,every bearing component（i.e.,rolling ball,inner raceway and outer raceway） has 6 degrees of freedom. Relative slippage and lubricant traction are also considered. Moreover,defects are modeled completely with consideration of additional clearance due to material absence,changes of Hertzian contact stiffness and changes of contact force directions. The relationships between bearing accelerations and impact forces at balls and defects are analyzed. Furthermore,the effects of the shaft speed and the defect width on bearing vibrations are investigated. The simulation results show that,because the relative slippage and the impact force effect are all considered,the proposed model is capable of simulating the dynamic characteristics of rolling ball bearings with surface defects more reasonable and providing valuable conclusions for fatigue analysis and quantitive diagnosis of rolling ball bearings.