精密齿轮传动是一种典型的关键基础件。研究高性能精密传动对于我国装备制造业及机械基础部件产业的振兴具有重要意义。本项目提出了一种能完全消除啮合间隙（无回差）、效率高、结构简单紧凑的新型无隙行星精密传动装置，其纯滚动接触啮合副由两组内齿轮与双联行星轮构成NN型结构，其中，内齿轮由若干呈锥面分布的滚动轴承组成，且内齿轮齿廓为滚动轴承外圆表面，双联行星轮齿廓为与之啮合的内齿轮齿廓曲面的包络曲面；该传动装置中的自动消隙机构可自动消除啮合副之间的啮合间隙并对其预紧。本项目将重点针对该新型无隙行星传动的基础理论开展研究，包括新型纯滚动接触啮合副的啮合原理、自动消隙机构的设计理论等，形成该新型传动纯滚动接触啮合副和自动消隙机构设计的核心技术，并通过试验测试获取基础性能数据，为其工业应用奠定基础。

The precision gear transmission is a typical key fundamental part. The research on the high performance gear transmission has significance on the revitalization of the industry equipment manufacturing and the mechanical fundamental parts. A new type of precision planetary gear transmission is proposed in this project, whose main characteristics are zero-backlash, high efficiency and compact structure. The pure rolling conjugated meshing gear pair is NN type and composed by two internal ring gears and a duplex planetary gear. The internal ring gear is composed by the rolling bearings, which are distributed in a cone surface. The tooth profile of the internal ring gear is the cylindrical surface of the rolling bearings, and the tooth profile of the duplex planetary gear is the conjugated enveloping tooth profile of the internal ring gear. The automatic elimination clearance device in this gear transmission can eliminate automatically the meshing clearance between the meshing gear pair. In this project, the fundamental theory of this new type of precision planetary gear transmission with zero-backlash will be studied, including the meshing principle and the design theory of the new pure rolling conjugated meshing gear pair, the design theory of the automatic elimination clearance device, etc.; the key technology of the pure rolling conjugated meshing pair and automatic elimination clearance device will be obtained; the fundamental performance data of this new gear transmission are also obtained by experiment research, which will lay a foundation for the industrial application.