在现代牵引动力机上,齿轮是一个重要的传动元件。它在实际工作过程中,往往承受着较大的、反复的弯曲应力。当工作应力超过齿轮本身强度时,将使齿轮在齿的危险断面——齿根部位产生疲劳裂纹,引起折断。从目前运行的传动齿轮的破损情况来判断,很大部分的损坏是属于此一原因。而就齿轮本身强度来说,除了与齿轮的材料有关外,往往在很大程度上取决于齿轮在热处理或表面热处理时产生的残余应力的大小。近年来,为了提高齿轮的弯曲疲劳强度, In modern traction power machines, the gear is an important transmission element. It is in the actual work process, often bear a larger, repeated bending stress. When the working stress exceeds the strength of the gear itself, it will make the gear in the dangerous section of the tooth - tooth root fatigue cracks occur, causing fracture. From the current transmission gear damage to judge, a large part of the damage is a reason for this. The strength of the gear itself, in addition to the gear material, often depends largely on the gear in the heat treatment or surface heat treatment generated when the size of the residual stress. In recent years, in order to improve the bending fatigue strength of gears,