针对当前机械装备对行星轮系“高承载能力的需求”和对行星轮系“体积和质量的限制”的矛盾，项目以凹凸接触S型齿轮行星轮系新齿形设计为切入点，以实现高承载能力、良好均载性能的凹凸接触S型齿轮行星轮系设计为最终目标展开研究。首先采用基于啮合线的齿形设计方法设计新齿形，基于微分几何、空间啮合理论、轮齿几何接触分析、轮齿承载接触分析，建立新型齿轮传动的啮合特性分析数学模型，系统的研究新齿形的几何接触与加载接触，并进一步研究其承载能力及啮合效率。在此基础上建立凹凸接触S型齿轮行星轮系静、动力学模型，分析误差、弹性支撑、太阳轮浮动、齿形对轮系均载和动载的影响，研究行星轮系均载设计，寻求并掌握最佳均载设计方法。最后通过样机的设计、制造与试验进行验证，全面实现凹凸接触S型齿轮行星传动设计理论的研究与实践。该项目的研究为凹凸接触S型齿轮行星轮系的设计和制造奠定理论基础，为高承载行星轮系的发展提供一个新的途径。

Due to the contradiction between the present mechanical equipment’s “demand for high load-carrying capacity” of planetary gear train and “restriction of volume and mass” of planetary gear train, the new tooth design of the S-gear planetary gear train with concave-convex contact is taken as the breakthrough point, and the design of the concave-convex contact S-gear planetary gear train with high load-carrying capacity and high load-sharing performance is taken as the ultimate goal to carry out the research in this project. Firstly, the new gear is designed using the tooth design method based on the meshing line, and the analysis model of meshing characteristics of the new gear drive is established based on the differential geometry, spatial meshing theory, tooth contact analysis and loaded tooth contact analysis to systematically study the geometric contact and loaded contact of the new gears, then, the load-carrying capacity and the meshing efficiency of the new gears are further studied. On the above basis, the static and dynamic models of the S-gear planetary gear train with concave-convex contact are established to analyze the effects of errors, elastic support, floating sun gear, tooth profile on the characteristics of load-sharing and dynamic of gear train. After that, the load-sharing design of the planetary gear train is studied, and the optimum design method of load-sharing is sought and mastered. Finally, the research and practice of the design theory of the S-gear planetary gear train with concave-convex contact is fully realized via the design, manufacture and experimental test of the prototype. The research of this project will lay a theoretical foundation for the design and manufacture of the S-gear planetary gear train with concave-convex contact and provide a new way for the development of planetary gear train with high load-carrying capacity.