Abstract:Roughness of Gaussian distribution can more accurately describe the rough outline curve amplitude distribution 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 runningin 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 multigrid 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.