Fracture Causes of Gear Teeth of Third Gear Shaft of Driving Reducer

The gear teeth fracture accident occurred in the process of using the third gear shaft of the driving reducer. The fracture causes of the gear teeth were analyzed by means of macro analysis, chemical composition analysis, micro fracture analysis, metallographic examination and hardness test. The results show that the fracture property of the gear shaft teeth was brittle overload fracture. The main causes of the gear tooth fracture failure were that the intersection angle between the gear end face and the tooth surface root was not chamfered, rough machining and short-time overload.