基于洛毕达极限法则的机构奇异位置运动分析

Kinematic Analysis at Singular Points of Linkages Based on L'Hospital's Theorem

提出了运用洛毕达极限法则分析机构通过死点或切换点时的角速度或速比的新方法 ,并具体应用于具有切换点的GRASHOFneutral机构和GALLOWAY机构的运动分析 .计算分析和实验结果证明 :这两种特殊的平面双曲柄机构的运动周期是原动曲柄旋转二整周 ,而并非通常的一整周 .发现当GALLOWAY机构的相对杆长差取很小值时 ,机构能输出具有超长近似停歇期和反向自锁特性的间歇运动 。

In this paper,using the L'Hospital's theorem,a new method for analysis of velocity or transmission ratio of mechanisms with dead points or change points is presented.According to this method,it is demonstrated that double crank planar four-bar linkages with change points (such as GRASHOF neutral linkage and GALLOWAY mechanism)can make the crank rotate two turns as a period of motion by the kinematic analysis and the experiments.