Abstract: According to the class I size synthesis theory based on the basic idea of releasing roller centers and cam axes，some basic theories and important conclusions were summarized to solve the optimal cam axes [O**1]which were the most eligible solution in the whole processes of obstacle avoidance perfectly.To propose a new algorithm aiming at solving the optimum solution of the mechanisms，an analytic criterion of rollers and cams for avoiding obstacles in the whole procedure and simplified search areas [Σ][2]and [Σ][0] were presented，and then brought forward an ergodic search method to solve the feasible areas of cam axes [O**1] and roller centers C through the whole processes of avoiding obstacle successfully.The dimensional synthesis of disk cam mechanisms for obstacle avoidance and compact floating roller pushrods were resolved.A mechanism synthesis example was displayed.

Key words: floating roller pushrod, class I dimensional synthesis, most eligible solution, obstacle avoidance success, solution area, compact size solution

摘要： 基于“双释放（释放滚子中心和凸轮轴心）的基本思想，根据Ⅰ类尺寸综合方法，分析推理得到最优凸轮轴心[O**1]是“整程避障成功”的最适任解，给出障碍集{Di}与许用边界{-Di}等若干概念，提出滚子、凸轮“整程避障成功”的解析判据，以及“简约搜索区域[Σ2]和[Σ0]”和求解凸轮轴心O1、滚子中心C解区域的遍历搜索方法，进而提出“机构紧凑尺寸解”的求解方法，圆满解决了面向避障和紧凑的浮动滚子推杆盘形凸轮机构尺寸综合问题。最后给出了机构尺寸综合的一个算例。

关键词: 浮动滚子推杆, Ⅰ类尺寸综合, 最适任解, 避障成功, 解区域, 紧凑尺寸解