空间谐波传动柔性齿轮的长寿命优化设计理论

新一代空间飞行器先进有效载荷在轨任务实施对谐波齿轮传动等核心活动部件提出了高可靠、长寿命服役要求。柔性齿轮由于承受连续交变载荷，是谐波传动最易发生破坏或失效的薄弱环节。项目以空间谐波传动柔轮为研究对象，探索特殊极端工况下其动态服役行为及传动界面失效机理。在此基础上，利用谐波传动动力学与微观界面力学，开展柔轮宏-微观力学多尺度结构优化设计；综合考虑空间环境热效应和传动副机械热载荷影响，开展柔轮传动副空间热环境适应性优化设计；揭示材料冶金及热处理显微组织对柔轮传动副界面力学行为影响，开展柔轮材料显微组织优化设计；建立柔轮固体润滑膜接触力学模型分析润滑膜-基体系统应力行为及剥落磨损机理，提出柔轮界面润滑膜优化设计与配伍理论及方法。项目借助柔轮加速寿命试验验证所提长寿命优化设计理论的有效性，最终建立空间谐波传动柔轮服役寿命主动优化设计准则，为空间飞行器核心活动部件高可靠长寿命应用奠定一定理论基础。

High reliability and long life are required for critical transmission part, such as harmonic gear drive, used in modern spacecraft in order to better fulfil on-orbit tasks. Due to experiencing continuous alternating load, flexspline is easier to suffer damage or failure, which becomes a weak component in harmonic drive. The present project focuses on flexspline in harmonic gear drive. The dynamic service behavior of flexspline under extreme conditions and its transmission interface failure mechanism are explored. Further, based on harmonic drive dynamics and interface mechanics, multi-scale optimization design for flexspline structure is conducted; with considering both the thermal effect of space environment and mechanical heat load caused by transmission, the thermal adaptive optimization design for flexspline is applied; the influence of material microstructure produced by metallurgy or heat treatment on interface mechanics is investigated to carry out microstructure optimization design for flexspline; based on the analyses on the stress distribution of lubricating film-matrix system and disbanding/wear mechanism through an established contact mechanics model for flexspline coated with solid lubricating film, the optimization design for interface lubricating film is conducted. Finally, accelerated life test for flexspline is performed to verify the effectiveness of the life evaluation theory. The present project is expected to develop a service life optimization design criteria for flexspline in harmonic drive, so that theoretical basis can be laid for long-life application for high-performance critical transmission part of spacecraft.