基于功能模块变换的齿轮连杆导引机构综合

刚体导引运动综合是机构设计中的典型问题，为避免采用Burmester运动几何学理论为基础的传统综合方法出现机构的结构类型和功能特性方面的缺陷，探讨基于机构功能模块相似变换的广义综合理论，建立以功能特性为主线的导引机构综合方法。由于该广义综合方法以标准机构功能模块为最小设计单元，为扩展其结构类型，对能够产生复杂运动规律的齿轮连杆机构进行研究，以建立相应的基本尺寸型机构功能模块。首先，通过对齿轮连杆机构的构型分析研究传动功能与导引功能之间的转换映射，将传动机构转化为导引机构；其次，采用复数矢量法进行齿轮连杆机构运动学分析，建立包括构件相对尺寸、导引转角函数、导引点轨迹和运动几何标识的全拓扑信息机构功能模块；然后，分析机构的尺寸参数及齿轮传动比参数和导引功能特性的双向映射规律，得出合理调整预选功能模块尺寸参数的方法，以确保求解机构满足预期的功能特性要求。最后，以某粉料产品加工生产线中要求实现手抓短暂平移导引功能的机构设计为例，分析和求解运动任务的几何标识，并提取预选齿轮连杆机构功能模块的几何标识，给出几何标识之间的相似变换方法，得到满足工艺要求的求解机构实际尺寸和位置参数，对设计结果的验证表明了该广义综合方法的有效性和实用性。

Synthesis of Geared Linkage Mechanism for Guidance Task Based on Function Module Transformation

Rigid body guidance synthesis is a typical problem in mechanism design. In order to avoid the defects by traditional synthesis methods based on Burmester kinematic geometry theory, such as the limitation of mechanism structure type and the uncertainty of mechanism function, a generalized function oriented geometric synthesis method based on similarity transformation of the mechanism function modules was discussed. Since the standard mechanism modules were considered as basic design units for this method, the structure type of guidance mechanism modules need to be extended for a larger solution space. Therefore, the geared linkage structure that can generate complex motion patterns was taken into account, aiming at the establishment of corresponding function module through kinematic analysis. At first, the transformation and mapping method between transmission function and guidance function were obtained through the configuration analysis of geared linkage, thus converting the transmission mechanism to the guidance mechanism through changing the rotation center of output gear. Secondly, the complex vector method was introduced for the kinematic analysis to obtain the guidance function, after that the geared linkage function module with full topology information was established, which includes the transmission characteristics as well as the guidance characteristics, i.e. the relative dimensional parameters, the guidance angle performance, the guidance point trajectory and the motion geometric identifier. Then, in order to obtain the method for adjusting dimensional parameters of the preselected function module, a bidirectional mapping rule between relative dimensions and achievable guidance functions was revealed. At last, a practical guidance mechanism design task for powder production with partial parallel guidance function requirement was given, the similarity transformation of geometric identifier between geared linkage function module and the guidance task was presented, then the actual solution mechanism size and position parameters which meet the technical requirements were obtained, finally the validity and practicability of the proposed generalized synthesis method were verified by the analysis of design results.