基于拟动力学的航空发动机主轴滚子轴承热弹流润滑分析

以D1842926航空发动机主轴滚子轴承典型工况为算例,基于拟动力学分析结果,获得滚动体与套圈之间的接触微区运动和受力状态,分别用Hamrock-Dowson(H-D)拟合公式,Wilson-Sheu(W-S)热修正公式和热弹流数值法得到最小膜厚,并与试验测试数据进行了对比,结果表明,H-D最小膜厚误差非常大,W-S热修正最小膜厚比H-D误差要小,但误差仍在40%以上,文中数值结果与试验数据较为一致,误差10%以内;对比不同速度下三种算法的最小膜厚分布,低速时三者较为一致,随着速度的提高,H-D最小膜厚误差越来越大,而W-S最小膜厚在速度增大到一定程度后反而降低;随着径向载荷的增大,润滑膜压力增大,膜厚减小,两端的压力略高于中间;随着转速增大,润滑膜膜厚增大,压力基本没有变化。

TEHL Analysis of Aero-engine Mainshaft Roller Bearing Based on Quasi-dynamics

Taking type D1842926 aero-engine mainshaft roller bearing under typical operating conditions as cases, based on quasi-dynamic results, the motion and force at micro-contact region are obtained, and the minimum film thickness(MFT) are calculated with H-D formula, W-S formula and thermal elastohydrodynamic lubrication (TEHL) analysis, the MFT of the 3 algorithms are compared with testing results, which indicate H-D MFT have a large error, though the error of W-S MFT is smaller than that with H-D formula, the error is still above 40%, the numerical analysis results show a well agreement with testing data and the error is within10%. The MFT under different velocities are compared with 3 algorithms, which show well agreements under low velocity, but the error of H-D MFT becomes larger with the increasing velocity, and W-S MFT become smaller as the velocityreachesa certainvalue; The global film pressure increase and the thickness decrease with the increase of radial load, the pressure in both ends are a little higher than that in the middle; The film thickness increase with the increase of velocity, but the pressure keep unchanged.