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.