Marine transmission gears usually have large size, and often experience severe working conditions, such as heavy load, large transmission power and high speed ratio, together with the effect of surface asperities, which cause coexisting lubrication-contact state and seriously stress concentration, and further may lead to micro-pitting and fatigue failure. In this paper, the subsurface stress prediction model of the timing transmission spur gears of marine engine is developed, together with considering real 3D machined surface roughness and mixed lubrication-contact state. Results show, when the contact bodies with perfect elastic behavior,the maximum von Mises stress appears on the surface and no longer shows regular distributions along the line of action because of the 3D roughness.The transverse turned surface can reduce the subsurface stress greatly, the shaved and ground surfaces cause large subsurface stress and high-pressure area on the surface. The influence of surface roughness on the stress state is increased under the special conditions of low velocity and high power density, and the contact state is greatly improved by optimizing the parameters of tooth width. Effects of different materials indicate nylon-nylon contact surfaces has the smallest maximum stress compared with that in other four pairs. However, nylon-nylon contact surfaces have the highest friction coefficients, which can easily lead to severe wear or scuffing failures.

船用传动齿轮通常尺寸大，常经受重载、大传动功率、高速比等恶劣工况，再加上表面凹凸不平的影响，造成润滑-接触状态并存，应力集中严重，进一步可能导致微点蚀和疲劳失效。本文开发了船用发动机正时传动正齿轮的亚表面应力预测模型，同时考虑了真实的 3D 加工表面粗糙度和混合润滑接触状态。结果表明，当接触体具有完美的弹性行为时，最大 von Mises 应力出现在表面上，并且由于 3D 粗糙度不再显示沿作用线的规则分布。横向车削表面可以大大降低次表面应力，剃光和磨削表面在表面产生较大的次表面应力和高压区。在低速、高功率密度的特殊条件下，增加了表面粗糙度对应力状态的影响，通过优化齿宽参数大大改善了接触状态。不同材料的影响表明，尼龙-尼龙接触面的最大应力与其他四对相比最小。但是，尼龙-尼龙接触面的摩擦系数最高，很容易导致严重磨损或擦伤失效。在低速、高功率密度的特殊条件下，增加了表面粗糙度对应力状态的影响，通过优化齿宽参数大大改善了接触状态。不同材料的影响表明，尼龙-尼龙接触面的最大应力与其他四对相比最小。但是，尼龙-尼龙接触面的摩擦系数最高，很容易导致严重磨损或擦伤失效。在低速、高功率密度的特殊条件下，增加了表面粗糙度对应力状态的影响，通过优化齿宽参数大大改善了接触状态。不同材料的影响表明，尼龙-尼龙接触面的最大应力与其他四对相比最小。但是，尼龙-尼龙接触面的摩擦系数最高，很容易导致严重磨损或擦伤失效。