相切型传递的加速度表现

摘要

The tangent mechanism composed by a round plate and a rocker bar is a classical training example for learning motion composite.However the conventional recipe of selecting the moving point and moving frame is not applicable to the case with arbitrarily smoothed edges.For analyzing the acceleration transmitted by the arbitrarily smoothed edge pair,the definition formulas of acceleration is used in this paper,and the involved velocities are determined by the base point approach.The key analysis covers some limits,such as the arch length changing rate,the limit of the secant direction and the derivative of the unitary vector of common tangent.The acceleration relationships along the common tangent and normal are achieved finally.%圆盘/摇杆类相切型传递机构是复合运动训练的典型题目,但是传统所用的动点/动系的做法无法推广到边缘曲线为任意形状的情形.为了分析相切型传递的加速度关系,笔者直接使用加速度的定义式,其中速度用基点法获得.通过分析弧长变化率、割线方向、公切线单位矢量导数等极限,最终获得了沿公切向和公法向的加速度分量关系.