粗糙度纹理对有限长线接触混合润滑影响

Effects of Rough Surface Topography on the Characteristics of Mixed Lubrication in Finite Line Contact

采用统一Reynolds方程建立有限长线接触混合润滑模型,研究横向、纵向和二维规则表面粗糙度的波长、幅值及工况变化对润滑影响.结果表明:波长、幅值与工况对三种表面粗糙度接触副的润滑影响类似;随着载荷增大,平均膜厚降低,摩擦系数、接触载荷比与接触面积比均增大;随着转速升高,平均膜厚增大,摩擦系数、接触载荷比与面积比均降低,其中摩擦系数随转速进一步增大而小幅升高.在润滑状态转换区域润滑特征参数变化显著,而其他润滑区域变化平缓.沿卷吸速度方向的压力与膜厚波动分布存在相位差,垂直方向则同相位;相同的工况和粗糙度参数时,纵向粗糙度分布更有利于接触润滑.

A mixed elastohydrodynamic lubrication （mixed EHL） is developed for finite line contact model with the unified Reynolds equation. This model is used to comprehensively show the effects of the wavelength and amplitude of roughness, working conditions on the three types of major roughness orientations： transverse, longitudinal, and isotropic. Results show effects of the wavelength and amplitude, as well as the working conditions were almost similar for three types roughness orientations. As the load increased, the friction coefficient, contact load ratio and contact area ratio increased, while the average film thickness decreased. As the speed increased, the friction coefficient, contact load ratio and contact area ratio decreased, while the average film thickness increased. The characteristic parameters of lubrication varied significantly from the full-film and mixed to boundary lubrication. Along the direction of entrainment velocity, it is misplaced for the distribution of pressure and film thickness fluctuation. The longitudinal roughness is more advantageous to contact lubrication.