中文摘要：

在旋转导向钻井系统中,可控弯接头是重要的导向钻井工具。介绍了可控弯接头结构,并对该结构中钢球的受力和接触情况进行阐述。采用赫兹理论对钢球与滚道进行分析计算,了解其在工作过程中具体的运动情况以及在受到工作载荷之后的摩擦磨损状态;通过MATLAB软件分析机构中各因素对摩擦应力的影响程度及趋势,为机构后续设计及改进提供依据。

英文摘要：

The controlled bent sub is an important steerable drilling tool of the rotary steerable drilling system.In this article,a brief introduction on the controlled bent sub is made,the force and the contact situation of the balls in the structure is elaborate as well.The balls and the raceways＇ stress were calculated with the Hertz theory to understand the friction and wear when they sustain the work load.The curves between each parameter and the friction and stress were plotted by MATLAB.According to this curves,each parameter＇s impact and trend on the friction stress can be found to provide the basis for subsequent designs and improvements for this institution.