Evaluation and Verification of Surface Durability of Power Transmission Triboelement Concerning of Micro-and Macro-Configuration

对机械提出了轻质、紧凑、高强度、高可靠性等要求，因此，高可靠性的评估和验证以及提高表面耐久性是最重要的课题之一。在这项研究中，进行了三维接触应力分析，同时考虑了牙冠等宏观结构和微观结构(如粗糙度、硬度和残余应力分布)，并对表面失效和耐久性进行了评估。对不同微观和宏观表面形态的滚子和齿轮副的表面失效和耐久性进行了检测和评价。对于表面宏观形态，研究了凸度对表面耐久性和牵引性能的影响。在无边缘载荷或边缘载荷较小的情况下，法向载荷下的滚动接触疲劳强度随凸度半径的增大而增大。相反，牵引性能随着冠化半径的减小而提高。阐明了高滚动接触疲劳强度和牵引性能相结合的最佳凸度的存在，以及动力传动摩擦机械零件凸度设计的重要性。在微观形态方面，测量了滚子和齿轮副喷丸、二次喷丸以及空化无喷丸等处理后的显微组织、残余应力分布和表面粗糙度。考虑硬度分布和残余应力分布的接触分析得到的应力与硬度之比的幅值适用于表面耐久性和疲劳寿命的评估。

Light weight, compact, high-strength, high-reliability and so on have been required to machines, therefore highly reliable evaluation and verification as well as improvement of surface durability is one of the most important subjects. In this study three dimensional contact stress analyses was conducted in considering of both macro-configuration such as crowning and micro-configuration such as asperity, hardness, and residual stress distributions, and the surface failure and durability were evaluated. The surface failure and durability were also examined and evaluated with rollers and gear pairs with various micro and macro surface configurations.As to surface macro-configuration, the influence of crowning on surface durability and traction performance was investigated. In case that no edge load or minor edge load occurred, the rolling contact fatigue strength evaluated with the normal load increased with increasing crowning radius. On the contrary, the traction performance increased with decreasing crowning radius. It was clarified that the optimal crowning, where both the high rolling contact fatigue strength and the traction performance were combined, exists and the importance of the crowning design of the power transmission tribomachine elements.As to micro-configuration, hardness distribution, residual stress distribution, and surface roughness of rollers and gear pairs with shot-peening, double shot-peening, and some other treatments such as cavitation shotless peening were measured. The amplitude of the ratio of the stress to the hardness obtained by the contact analyses in consideration of hardness distribution and residual stress distribution measured would be suitable for evaluation of the surface durability and the fatigue life.