Abstract: From the view of fractal theory and topological graph,a systematic synthesis methodology and a novel analysis approach of two-Translational and two-Rotational (2T2R) hybrid mechanisms were proposed.The basic concept of topological graph and the fractal theory were introduced.The kinematic characteristic and algorithm were expounded,the kinematic characteristic was composed by route,branch and kinematic pair,while the algorithm was comprised of route rule and the calculation rule of union-intersection-preserving.The model between hybrid mechanism and fractal theory was established,and the procedure of type synthesis methodology was concluded in detail.Meanwhile,the three translational hybrid mechanism was synthesized.A method for analyzing the kinematic characteristic of 2T2R hybrid mechanisms was proposed and applied to the synthesized structure by which the validity of the proposed methodology was demonstrated.

Key words: hybrid mechanism, type synthesis, fractal theory, two-translational and two-rotational

摘要： 为综合得到具有两移两转运动特征的混联机构,基于分形理论和机构拓扑图,提出一种系统的混联机构型综合与分析方法。介绍了机构拓扑图和分形理论的概念及关系;叙述了机构的运动特征和运算法则,运动特征包括路径、支链和运动副的定义与表达形式,运算法则含有路径法则串并联计算规则;建立了混联机构与分形的关系模型,归纳出混联机构构型综合的具体步骤,并综合出具有两转两移运动特征的混联机构。提出混联机构运动特征的分析方法,并用该方法分析了所综合出的两转两移混联机构的末端运动特征,验证了该构型的正确性,证实了所述方法的可行性。

关键词: 两转两移混联机构, 构型综合, 分形理论, 运动特征