基于拟动力学的航空发动机主轴球轴承热弹流润滑分析

以航空发动机主轴球轴承高速高温重载典型工况为算例,基于轴承拟动力学分析,得到滚动体与套圈之间的微接触区运动和受力状态,分别用Hamrock-Dowson(H-D)拟合公式和翟文杰热修正公式计算了最小膜厚(MFT),同时结合热弹流润滑分析得到最小膜厚分布,对比了试验测试、H-D拟合、翟文杰热修正和热弹流润滑分析4种算法的最小膜厚,并根据膜厚比判定了轴承的弹流润滑状态.结果表明:H-D拟合和翟文杰热修正最小膜厚与试验测试结果相差较远,热弹流润滑分析结果与试验数据吻合性较好,误差10%以内;探讨了不同工况下的轴承弹流润滑性能.结果表明:存在径向载荷时,润滑膜整体压力增大,膜厚减小;随着转速增大,压力减小,膜厚增大,但是增大的趋势减缓. 

Thermal elastohydrodynamic lubrication analysis of aero-engine mainshaft ball bearing based on quasi-dynamic

Taking aero-engine mainshaft ball bearing under typical high speed and load conditions as cases, the motion and loaded states of micro-contact region were obtained based on quasi-dynamic analysis, and the minimum film thickness(MFT) was estimated with Hamrock-Dowson(H-D) formula and ZHAI Wenjie thermal modified formula; meanwhile, the MFT under various conditions was acquired through thermal elastohydrodynamic lubrication(EHL) analysis. Comparing the MFT of experiment testing, H-D, ZHAI Wenjie and numerical analysis, the EHL status was ensured by film thickness ratio. Results indicate that H-D and ZHAI Wenjie's MFT have large difference with experiment results, but numerical analysis shows a well agreement with experiment data and the error is within 10%.The operating condition effects on EHL property were discussed. Results indicate the global film pressure increases and the thickness decreases in the presence of radial load; the film pressure decreases and the thickness increases with the increase of speed, but the trend becomes slower.