Abstract: Abstract The extendible cone of the double extendible nozzle is a spatial symmetrical mechanism and indeterminate issue.The distortion of the cone is difficult to work out.Refer to double muffle actuator,it is three supports girder and indeterminate issue.The fits between inner actuator mid actuator and outer actuator are glide fit,because information seal between them is rubber ring and it′s distortion is complex,information reaction of supports is difficult to calculate,but,calculated the reaction of supports is key to solve design of joint parts of cone and nozzles. On the basis of calculating the motion of the mechanism and dynamics parameters,we work out the reaction of supports using simplified method.

摘要： 双级延伸喷管的基础锥和一、二级延锥为一空间对称机构，属超静定问题，是解决锥体与作动筒之间联接件结构设计的关键。为此，在用数值计算方法求解机构运动参数基础上，采用近似法解决了支反力的求解问题。计算结果与加速度试验曲线基本一致，为作动筒设计提供了可靠的理论依据。

关键词: 火箭发动机;可延伸喷管;绞接;静定结构;挠性支持