Dynamic Characteristics Analysis And Fatigue Life Study Of A Transmission Gear

Transmission gears are the core component to realize transmission function,it is necessary to study its dynamic mechanical properties and fatigue life.In this paper,dynamic finite element analysis was used to analyze the meshing of the transmission gears,and studied the fatigue of gears based on the dynamic analysis results.Established the model of gears based on the design theory of involute helical gears and the detailed parameters of transmission gears.The transmission gears system is assembled according to the structure and arrangement of transmission.Meshed the gears in the pre-processing software.Calculated the torque and speed of different gears when the torque of the engine is the maximum,and the speed reaches the maximum in the maximum torque condition,then set the boundary conditions of gear analysis.Analyzed the stress distribution and change of gears based on the finite element dynamic analysis method.Compared the the maximum contact stress and the maximum bending stress with the allowable stress calculated by theory,both contact stress and bending stress met the strength requirements.During the dynamic meshing process,the meshing number,the meshing position and the length of the contact line all have certain influence on the contact stress and the bending stress.Analyzed the influence of surface friction coefficient,load torque and speed on the dynamic stress of the gears.When the friction coefficient is bigger,the load torque is bigger and the speed is faster,the contact stress and bend stress will increase.Used the maximum stress in the dynamic meshing of the gears as the stress input,set the load spectrum,defined the contact fatigue property curve and the bending fatigue characteristic curve of the gears,then predicted the contact fatigue life and bending fatigue life of gears.The results show that the fatigue life of each gear in line with standard requirements.Finally,the durability test of transmission gears was carried out on the test bench,the results verified that the transmission gears meet the fatigue requirements.