微观形貌表征对直齿轮跑合弹流润滑的影响

Effect on Elastohydrodynamic Lubrication of Spur Gear Running-in by Microstructure Characterization

高斯分布粗糙度函数相比余弦粗糙度函数,能更贴近地描述跑合前齿面粗糙轮廓曲线幅度分布。研究高斯分布的齿面粗糙度对齿轮跑合过程中轮齿间油膜压力和膜厚的影响,探讨瞬态效应对轮齿润滑的影响,利用多重网格技术求得齿轮瞬态微弹流润滑的完全数值解。结果表明:采用高斯分布粗糙度时油膜压力变化明显,更符合啮合点出现粗糙峰而形成的轻微冲击对轮齿间油膜的影响,而采用余弦粗糙度时油膜压力则变化相对比较缓和;采用高斯分布粗糙度的最大油膜压力明显大于采用余弦粗糙度的最大油膜压力,故按照余弦粗糙度计算的最大油膜压力与实际最大油膜压力可能有较大偏差。

Roughness of Gaussian distribution can more accurately describe the rough outline curve amplitude distribu- tion of tooth surface before running-in than cosine roughness function. The effect of Gaussian distribution roughness on gear tooth lubrication oil film pressure and thickness during running-in was studied, and the influence of the transient effect on gear lubrication was discussed. The complete numerical solution about micro transient elastohydrodynamic lubrication of spur gear was obtained through muhigrid technique. The results show that, as compared to cosine roughness, there is an evident oil film pressure variation when considering roughness as Gaussian distribution, which conforms more to the influence of mild shock from rough peak at mesh point on oil film between gear teeth. However, the oil film pressure change is rather mild when considering roughness as cosine function distribution. The maximal oil film pressure with Gaussian distribution roughness is obviously much greater than that with cosine function roughness, therefore, the maximal oil film pressure calculated according to cosine function roughness may have larger deviation compared to the actual maximal oil film pressure.