考虑轴颈涡动的滑动轴承动力特性数值研究

Numerical study on dynamic characteristics of journal bearing considering journal whirling motion

基于非定常动网格技术建立了考虑轴颈涡动频率与涡动轨迹的滑动轴承动力特性求解模型。在验证求解模型准确性的基础上,研究了轴颈正弦直线涡动轨迹、圆涡动轨迹、椭圆涡动轨迹下,涡动频率和偏心率对滑动轴承动力特性的影响。研究结果表明:轴颈的周期性涡动导致轴承油膜最小间隙和油膜压力周期性变化,油膜最小间隙越小,油膜压力越大;随着轴颈正弦轨迹涡动,由此形成的油膜力也呈正弦规律变化,且变化频率与轴颈涡动频率相同,但油膜力的相位滞后于轴颈涡动位移的相位;轴颈涡动频率及涡动轨迹对滑动轴承动力特性影响较大,需要考虑轴颈涡动对滑动轴承动力特性的影响。随着偏心率的增加,动力特性系数绝对值均随之增大。

The unsteady solution combined with mesh deformation technique was used to establish a solution model of the dynamic characteristics of journal bearing in consideration of whirling frequency and orbit of the journal. On the basis of verifying the accuracy of the so-lution model, the influences of whirling frequency and eccentricity on the dynamic character- istics of journal bearing were studied when journal whirled with sinusoidal orbit, circular or- bit and elliptical orbit. Study results indicate that the radical clearance and oil film pressure change along with the whirling motion of the journal. The smaller radical clearance means the greater oil film pressure. With the sinusoidal whirling orbit of the journal, oil film forces change, and the frequency of the oil film force is the same as whirling displacement of the journal. However, the phase of oil film force lags behind the whirling displacement. The whirling frequency and orbit of the journal greatly influence the dynamic characteristics of journal bearing, so the whirling motion of the journal should be considered. With the in- crease of eccentricity, the absolute value of the dynamic coefficients increase.