急回机构中非圆齿轮节曲线的设计

提出了一种以非圆齿轮为前置机构的急回机构。将非圆齿轮节曲线的设计分为等速行程和过渡行程两段进行讨论，通过对所得三种传动比函数的比较，确认了两种较为理想的传动比函数。使所设计机构能实现输出件在工作区间内完全等速，且具有较好的急回特性，比传统的六杆急回机构能更好地满足实际应用中的不同需求。

DESIGN OF THE PITCH CURVES OF NONCIRCULAR GEARS FOR QUICK RETURN MECHANISM

A quick return mechanism incorporating noncircular gears is presented. During the course of designing, the noncircular gears' pitch curves are divided into two parts to discuss, i.e. uniform-velocity range and accelerating range. Two kinds of superior speed-ratio functions are accquired by comparing three kinds of speed-ratio functions which are attained here. The designed mechanism can make the output part get uniform velocity in the working area and better quick return character. It is more suitable for different needs than traditional six-bar quick return mechanism in practical applications.