链环式超越离合器自锁条件及数学模型

Selfhold condition and its mechanical model of chain-ring overrunning clutch

链环式超越离合器是一种原创性的、高性能的摩擦式超越离合器,其自锁条件的数学模型一直以带传动的Euler公式作为条件判据,与实际的情况有很大的偏差。该文对链环式超越离合器的自锁条件进行了深入分析,通过建立精确的力学模型、分析机构工作原理的本质,重新定义了其自锁条件判据。新判据的计算结果为两个随工作状态变化的量纲1的数据比较,实验证明其真实反映了超越离合器的自锁情况。新数学模型可作为该离合器设计和研究的指导依据,对于该离合器的产品化、系列化有很重要的意义。

The chainring overrunning clutch is a recently introduced friction overrunning clutch. A simplified mechanical model was used to analyze the selfhold condition using Euler's expression, but experiments showed that there were considerable errors. This paper presents a new model based on further analysis of the working principles which showed that Euler's expression is not suitable for the selfhold condition of a chainring overrunning clutch. The result compares two dimensionless parameters that are functions of the mechanism state. Experiments show that the result precisely describes the selfhold condition of a chainring overrunning clutch so the model can be used for product design.