摘要
可动性问题是Stephenson六杆机构综合与分析中最基本也是最困难的问题,它包括回路缺陷、曲柄存在和运动顺序等问题的判别。将Stephenson六杆链看作一个基础四杆链和双杆组组成,则其回路特性由基础四杆链的回路特性与双杆组的构形以及他们的相互作用决定。基于基础四杆链和双杆组的两个公共副之间的距离,提出了Stephenson六杆链回路的识别原理和方法,给出了回路缺陷的判别方法及实现步骤,推导了各种Stephenson六杆机构曲柄存在条件,得到了一种与主动副无关的机构运动顺序问题的判别方法。系统地解决了Stephenson六杆机构精确点综合中最棘手的三个问题并易于计算机自动设计,对于机构的分析和综合有重要的参考价值。
The mobility problem is most fundamental and most difficult in the process of Stephenson six-bar chains analysis and synthesis. They are referred to the problems associated with the circuit defect, the existence of a crank, and the order of motion. A Stephenson six-bar chain is composed of a basis four-bar chain and a dyad, and its circuit properties are determined by the circuit properties of the basis four-bar chain and the configurations of dyad and the intersection between them. Based on the distance of two common joint between the basis four-bar and the dyad that a Stephenson six-bar chain contains, the theory and method to identify the circuits of Stephenson six-bar chain are presented. The procedures of identifying circuit defect are given, the conditions of crank existing of any type of Stephenson six-bar linkages are deduced, and the method of determining whether Stephenson six-bar linkages satisfy the order of motion is gained. The results resolve three of the most troublesome problems encountered in the precision point synthesis of Stephenson six-bar linkages. This research has significant value for linkages analysis and synthesis.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2004年第11期26-34,共9页
Journal of Mechanical Engineering
基金
国家自然科学基金重点资助项目(50135040)
