For the analysis of fatigue crack propagation of spur gears, the calculation of crack propagation life of spur gears is a very important link. The accurate prediction of crack propagation life of spur gears is helpful to prevent serious accidents in the operation of parts. By predicting the crack propagation life, the work of parts can be interrupted in advance before fracture. The main work of predicting the fatigue crack propagation life of spur gears is to study the crack propagation life in the fatigue fracture process. Although the fracture process is divided into three steps, there are many difficulties in predicting the crack initiation life, mainly using damage mechanics and nondestructive testing technology; The third step instability propagation in the fracture process is of little significance to reality. At present, the research on the fatigue crack life of spur gears mainly focuses on the crack propagation life. Using the formula to predict the crack propagation life by calculating the crack propagation rate of spur gears is the most common method.
Based on the data obtained by simulating the crack propagation process of spur gear, the crack propagation life and crack propagation rate of spur gear fatigue crack under different tooth direction distributed loads are calculated. The main conclusions are as follows:
(1) The crack propagation rate of spur gear is calculated. The results show that under the same load, the longitudinal crack propagation rate is slower than the transverse crack propagation rate of spur gear; Under different loads, the uneven load distribution along the tooth direction will accelerate the crack propagation rate of spur gears.
(2) The crack propagation life of spur gear under ideal uniform load and actual load is predicted. The results show that uneven load distribution will reduce the fatigue life of gear.