Failure Analysis of Transmission Gear for Heavy Vehicles

For early failure problems, which are broken teeth of the first transmission driving gear in the test, this paper studies the problem in the failure mechanisms such as chemical composition analysis, fracture surface analysis as well as the metallographic structure morphology inspection analysis of failure gear. The results show that the main reasons causing abnormal fracture of the failure gear are the insufficient root shot peening strengthening, the small fillet of the spline groove and the inadequate rim thickness of the rim. This paper uses the finite element method to analyse the contact stress of failure gear and puts forward an improving design method.