Abstract:Load spectrum is the key to the prediction of gear residual fatigue life. In order to accelerate the fatigue test and improve the prediction efficiency of residual fatigue life, a method of compiling the program load spectrum of gear based on Rain-flow counting was proposed. By analyzing the load of gear teeth in a meshing period, the corresponding dynamic load spectrum was extracted, and the Rain-flow count of the load spectrum was realized by the recursive algorithm of Rain-flow count. The mathematical model of counting results was determined by hypothesis testing,and the probability density function was determined by maximum likelihood estimation.The maximum load was determined,and the program load spectrum was established.Based on the established program load spectrum,gear life was predicted by Miner fatigue accumulation hypothesis and local stress strain method. The predicted results are basically consistent with the fatigue test results,which proves the validity of the program load spectrum.