齿轮的常见失效形式有点蚀、胶合、磨损及疲劳折断等几种,对于它们发生的机理目前还不十分清楚。本文试用摩擦学知识来对前三种失效形式进行初浅的解释。先简要地介绍轮齿工作表面的相对滑动情况,并用表面力学来分析接触表层材料的应力分布。这是一种交变应力,当应力大小超过极限值时,早期微裂纹会失稳扩展导致了疲劳点蚀, The common failure forms of gears are pitting, gluing, wear and fatigue breakage, etc., and the mechanism of their occurrence is not yet clear enough. This article tries tribology knowledge to explain the first three forms of failure. Briefly introduce the relative sliding of the gear tooth surface, and use the surface mechanics to analyze the stress distribution of the contact surface material. This is a kind of alternating stress, when the stress exceeds the limit value, the early microcracks will instability expansion lead to fatigue pitting,