平面单自由度多环机构传递特性评价

摘要

Based on Assur group theory,the structural features of planar single DOF multi-loop mechanism are analyzed.According to topological relationship between Assur group and input/output links of the mechanism,the general description method of planar single DOF multi-loop mechanism is given.Based on this,the transmission of Assur group is defined with the concept'virtual coefficient'in screw theory.The transmission index of single DOF multi-loop planar mechanism is given accord to the connection relationship of Assur group.Finally,one cam-linkage mechanism is proposed as an example for the transmission analysis compared with the traditional methods.The result proves that the proposed method is closely related to the actual working state of the mechanism and verifies the effectiveness of the transmission index.%基于Assur杆组理论,分析平面单自由度多环机构的结构特征,根据Assur杆组与机构输入和输出构件之间的拓扑关系给出平面单自由度多环机构的一般化描述方法.在此基础上,采用螺旋理论的虚系数概念,定义Assur杆组的传递特性,根据杆组之间连接方式构建出平面单自由度多环机构的整体传递特性指标.以一种凸轮连杆机构为例进行传递特性分析,该种方法与机构的实际工作状态密切相关,验证了传递特性指标的有效性.