几何与动力约束结合的凸轮机构基本尺寸优化

Size Optimization of Cam Mechanisms due to the Combination of Both Geometric and Dynamic Constraints

考虑凸轮与转子间最大压力角及凸轮轮廓最小曲率半径等几何约束条件的同时 ,结合最大接触压应力、最大剪应力等动力约束条件 ,对凸轮机构基本尺寸优化问题进行了研究 ,提出了优化方法。最后辅之实例 ,结果表明低速时上述最小尺寸由几何约束条件控制 ,中速时主要受动力约束条件限制 ,高速时则完全由动力约束条件所主宰。

In the paper, the dynamic response of the cam mechanism with a translating roller follower and without impact vibration between the cam and the roller is presented. The problem of size optimization of the cam is analyzed under both geometric constraints, which mainly consist of the maximum pressure angle and the minimum radius of curvature, and dynamic constraints, namely the maximum stress and the shearing strength at the contacting area between the cam and the roller. Comparisons of the corresponding results of size optimization under different cam angular velocities and different follower displacement throws are illustrated by a numerical example. It can be concluded that the minimum size of the cam is reined by geometric constraints at lower angular velocity region and governed by dynamic constraints at the higher one.