具有局部表面损伤的滚动球轴承动力学建模

Dynamic Modeling and Vibration Response Simulation for Rolling Ball Bearings with Local Surface Defects

提出了一种滚动球轴承局部表面损伤故障的动力学分析方法。模型中每个轴承元件具有6个运动自由度,并完整地考虑了陀螺效应、离心力及润滑牵引等动力学因素。通过几何特征的变化对局部表面损伤进行了建模。采用四阶变步长Runge-Kutta-Fehlberg积分法对动力学方程进行了数值求解,并在时域和频域中对动力学响应进行了分析。研究结果表明,由于考虑了润滑剂的牵引效果,计算得到的故障特征频率较纯滚动假设下的计算结果有一定的差异。文中综合考虑了轴承元件的三维运动、相对滑动、润滑效应以及局部表面损伤等因素,因此所提出的模型更为全面、有效和实用。

A dynamic model is developed in order to simulate the vibrations of rolling ball bearings causedby local surface defects on bearing raceways.In this model,each bearing element(i.e.inner ring,outer ring and rolling balls)has 6degrees of freedom to completely describe its dynamic characteristics in threedimensional space.The model incorporates gyroscopic effects,centrifugal forces,and lubrication tractions between bearing elements.Additionally,the vibration effect of local surface defects in raceways is modeled through surface profile changes.The obtained equations of motion are solved numerically by using a fourth order Runge-Kutta-Fehlberg scheme with a step-changing criterion.Vibration responses of the bearing are analyzed in domains of both time and frequency.Because lubrication tractive forces are considered,characteristic defect frequencies calculated by the dynamic model are less different from the ones calculated on the assumption of pure rolling.The proposed model contains the three dimensional motions of each bearing element,relative slippage,lubrication effects,and local surface defects,which is more comprehensive,effective,and practical than studies currently available in literature.