圆弧等宽凸轮廓线的设计与分析

Design and Analysis of Constant Breadth-Cams with Circular Arc Profile

本文对框架从动件在极限位置上具有仃歇而位移轮廓角Φ≠120°的对称圆弧等宽凸轮及不对称圆弧等宽凸轮的几何尺寸公式进行推导.另外,对不对称圆弧等宽凸轮外廓的最小尺寸H_0、尺寸A的极限范围及运动规律进行分析研究,得出的结论适用于从动件在极限位置上具有仃歇的所有圆弧等宽凸轮.当Φ>120°时,存在多种凸轮廓线,均在框架行程h相同条件下,具有相同的最小尺寸H_0,但各凸轮廓线互不相同,可供设计人员任意选择以满足生产要求.并附有设计举例.

In this paper the author has developed the formulae for calculating the geometrical dimensions of constant-breadth cams conjugating with rectangular frame-shaped followers which have a dwell at the upmost or lowest position.The cam profile may consist of either symmetmical or non-symmetrical circular arcs and the displacement angle of its profile of the formerΦ is not equal to 120 degrees.In addition, for the non-symmetrical cam the minimum breadth H0, the limitations of the dimension A(i.e.the distance between the cam totating center and any other center of the profile are)and the kinematic behaviour are examined. The results obtained by the author are applicable to any constant-bredth cam with circular arc profile for a follower which has a dwell at its extreme positions.When the displacement angle of profile is greater than 120 degreee for the same follower stroke h there are many different cam profiles with the same breadth H0.it makes the designer chose the most suitable one to meet his engane-ering requirements.A design example is also included to illustrate the application of the theory developed in this paper.