【作者】 曹兴进；

【导师】 张光辉； 韦云隆；

【作者基本信息】 重庆大学 ， 机械设计及理论， 2003， 博士

【摘要】 提高齿轮齿面的承载能力一直是人们研究的重点，本文根据国家自然科学基金重点项目课题（No：59235082）及国家自然科学基金面上项目（No：59905024），围绕依托啮合理论和原位摩擦化学处理耦合研究产生的新构想——在线强化零件表面的技术，这一学科前沿进行了下列研究工作：为了使工作简洁，选用了一对直齿圆柱齿轮（spur gear pair），运用啮合理论对其齿面的共轭啮合进行仔细分析，建立了等效运动模型；运用弹性流体动力润滑理论（Elasto-Hydrodynamic Lubrication, EHL）对齿面间的润滑油膜厚度进行了计算，并通过油膜参数对齿面间的润滑状态进行了评估。按《GB3480-83渐开线圆柱齿轮承载能力计算方法》对齿轮的承载能力进行了计算。以无机硼酸盐为抗磨添加剂，按《GB11144-89 润滑油极压性能测定法（梯姆肯试验机法）》对制备的三组润滑油测定了OK值，其中3#油，即：ISOVG68机械油+5%Na2B4O7+2%RE纳米粉+1%BOA+1%T154为最高，达222.4N 。自己设计、搭建了功率流开放式齿轮运行实验台，并选用3#油为实验用润滑油，与ISOVG68机械油作润滑油进行对比实验。实验的结果为：ISOVG68机械油作润滑油时，在输入3000rpm，5.96Nm时，齿面发现沿节线出现大面积的点蚀，且齿面有塑性变形；以3#油为润滑油时，在输入3000rpm，8.59Nm时，齿面发生了明显的齿面塑性流动(plastic flow)，主动轮（小齿轮）在节线处出现明显的沟槽，从动轮（大齿轮）在节线处出现明显的棱脊，大小齿轮工作齿面均十分光洁，未发现点蚀现象发生。通过齿轮的表面分析（仅对用3#油的实验齿轮进行）发现：硼元素在齿轮表面的共轭啮合过程中，已渗进了齿轮的表面，形成了与基体的结构、性能完全不同的表面改性层；齿轮表面粗糙度下降了，这显然是跑合使得齿面的微小凸峰被大为减低的结果；齿轮表面的显微硬度提高了，这是由于硼元素渗进齿轮表面形成改性层和塑性流动造成加工硬化的协同作用的结果；通过这些研究指出了传统的齿轮润滑状态与表面损伤评估体系存在的问题：即按弹性流体动压润滑理论对齿轮传动副在给定的工况下进行计算，得出齿面间的润滑油膜厚度，再计算油膜参数，然后对油膜参数的评价而达到对齿轮表面损伤进行评估，未考虑到在边界润滑状态下，添加剂分解出的活性原子向齿轮表面渗透，形成与齿轮基体的结构、成分、性能完全不同的表面改性层，极大的提高了其抗疲劳强度。也指出了等效于ISO/DP6336/Ⅰ∽Ⅲ-1980的《GB3480-83渐开线圆柱齿轮承载能力计算方法》的缺陷：在考虑齿面间润滑状态对齿面接触强度<WP=6>承载能力影响时，是以弹性流体动力润滑理论为讨论问题的基础，未考虑边界润滑状态下，非活性润滑油抗磨添加剂在啮合过程中，由于各种有利因素会分解出活性原子，渗进齿轮表面，形成表面改性层，极大的提高了其承载能力。提出了对润滑剂系数进行修正的添加剂修正系数的设想和设计准则，即添加剂修正系数的主要考虑因素为齿轮副传递的载荷、转速、中心距、齿轮副的材料。同时，对添加剂修正系数的使用规范进行了探讨。更多还原

【Abstract】 Researchers often focus on raising the loading capacity of gear surface. Thus this paper, integrating mesh theory and in-situ trbochemical treatmeant, studies a new method---conducting the following research work by the technique of on-line strengthing the components’ surface.To make it simpler, a pair of spur gear is chosen to be carefully analyzed on its surface conjugate meshing by means of mesh theory, then a model of equivalent movement is built up. Next, the film thickness between the gears is calculated by using Elasto-Hydrodynamic, and its lubricating state is evaluated by using film parameter. Finally, the gear pair loading capacity is worked out based on 《GB3480-83 Methods for the calculation of load capacity of involute cylindrical gears》.Using inorganic borate as the anti-friction addictive, based on 《GB11144-89 Lubricating fluids—Measurement of extremeprssure properties—Timken method》, we get the OK value of three groups of lubrication oil, among which, No.3 oil, that is, ISOVG68 mineral lubricant+5%Na2B4O7+2%RE nanometer powder+ 1%BOA + 1% T154 is the highest, 222.4N.Self-designed and built gear rig with opened power circulation, No.3 oil is chosen as the lubrication oil for the experiment, an comparative experiment is made with ISOVG68 mineral lubricant as the lubrication oil. The result is: when ISOVG68 mineral lubricant used as the lubrication oil, put in 3000rpm，5.96Nm, the pitch line of the gear surface is found extensively pitting and the gear surface plastically deformed. When No.3 oil is used, put in 3000rpm，8.59Nm, the gear surface has an obvious plastic flow, an obvious groove is found on pitch line of the driving gear (the smaller one), an obvious edge is found on pitch line of the driven gear (the bigger one). The operating surfaces of both driving gear and the driven one is high in smooth finish, no pitting.Through the analysis on the gear surface (only based on the gear in experiment with No.3 oil), it is found that: boron on the gear surface permeates the surface in the process of conjugate meshing and forms the modifying layers totally different from its basic structure and function. The roughness of the gear surface reduces which is caused by much fewer tiny asperity on the gear surface due to running-in. In addition, microhardness of the gear surface has raised due to joint function of processing hardness since the boron on the gear surface permeating the surface forms modifying <WP=8>layers and plastic flow. Through this experiment some problems in the evaluation system of the traditional gear lubricating state and surface damage are pointed out, that is, the first, based on EHL the film thickness between the gears is calculated, the second, the film parameter is calculated, finally its lubricating state is evaluated by using film parameter and thus the surface damage of the gear is worked out. In the above it is ignored that in the state of boundary lubricating, the active atom resolved from the additive permeates the surface and forms the modifying layer totally different from its basic structure, elements and function and thus greatly raises the anti-fatigue strength. The drawback with GB3480-83 Methods for the calculation of load capacity of involute cylindrical gears equivalent to ISO/DP6336/I∽III-1980 is also pointed out: when taking into account lubricating state of gear surface influence on loading capacity of gear surface, In the above it is study on based EHL , and is ignored that in the state of boundary lubricating, as well as favorableness conditions in gear surface conjugate meshing, the active atom resolved from the additive permeates the surface and forms the modifying layer totally different from its basic structure, elements and function and thus greatly raises the loading capacity of gear surface . Idea and design rule of additive correcting coefficient , for correcting lubricant coefficient , is put forward. i.e. additive correcting coefficient mainly is related with load drove by gear pair, rotate speed, center distance, material for更多还原