上传主动锥齿轮断裂分析

发动机返厂检查发现上传主动锥齿轮的一个轮齿发生断裂。通过对断裂齿轮进行断口宏微观分析、金相组织和硬度检查，分析认为锥齿轮的断裂性质为弯曲疲劳，疲劳断裂的原因是齿根弯曲应力过大。对齿轮齿厚、齿根圆角进行测量，对齿根圆角过渡情况进行检查，并运用有限元分析方法对锥齿轮断齿受力进行模拟分析。结果表明:齿根弯曲应力过大是因为齿厚超差导致齿轮啮合位置偏离，同时齿轮在加工过程中齿根存在加工接刀尖边导致齿根应力分布改变，出现应力集中。后续采取改进齿轮的加工工艺及加强对齿轮的制造质量控制等措施，避免该类故障再次发生。

Fracture Analysis of Active Bevel Gear

It is found that one tooth of an active bevel gear is broken by an engine return inspection. Through macroscopic and microscopic analysis, metallographic structure and hardness test of fracture gear, analysis shows that the fracture property of bevel gear is bending fatigue, and the reason of fatigue fracture is the excessive bending stress of tooth root. Check the tooth thickness root fillet measurement and root fillet transition. And the finite element analysis method is used to simulate the force on the broken teeth of the bevel gear, results show that the bending stress is too large because the tooth thickness tolerance the gear meshing position deviation of gear at the same time, in the process of root tip caused by root processing with changes of stress distribution, stress concentration. After that, measures such as improving the processing technology of gears and strengthening the manufacturing quality control of gears were taken, and no such failures occurred again.