Research and development of bending fatigue of heavy duty transmission gears

He Xiaohua of Chongqing University analyzed and studied the bending fatigue strength of 20CrMoH gear. Combined with mathematical statistics theory and reliability principle, the bending fatigue strength of this kind of gear is analyzed by using test method and finite element analysis method, and the fatigue life of gear teeth is estimated by ANSYS / FE-SAFE.

Li Jinpeng of Dalian University of technology used the APDL parametric modeling function of ANSYS software to model the gear. With the help of ANSYS finite element analysis software, the gear rack meshing of the lifting system of a domestic offshore drilling platform was analyzed, and the tooth root bending stress and tooth surface contact of the gear teeth with large modulus were analyzed.

Li Zhihai of Henan University of science and technology deduced the bending fatigue strength test method suitable for bevel gears by using the bending fatigue strength method of spur gears. A pair of 20CrNiMo meeting the requirements are designed by using the finite element software ansysworkbench, and the limit torque range of the test bevel gear is predicted according to the bending fatigue limit of the cylindrical gear, the service environment and geometric parameters of the test bevel gear. Finally, the conversion relationship between the applied torque and the bending stress of the small gear root is obtained, It provides data support for subsequent simulation and test. According to the above method, a set of spiral bevel gears meeting the requirements is designed.

Taking helical gear as the research object, Wu Zhenpeng and others modeled helical gear, simulated the crack propagation path in three-dimensional state by using ABAQUS software, created healthy gear and gear models with cracks at different depths, analyzed the influence of cracks at different depths on gear meshing stiffness, and made a vibration test-bed, The vibration signals of healthy gear and cracked gear are analyzed, and the frequency domain characteristics of different crack lengths are obtained.

Taking the involute cylindrical gear with initial crack at the root as the research object, Liu Xinbo et al. Studied the fatigue crack propagation characteristics and life of the tooth root. Through the application of linear elastic fracture mechanics, the crack propagation is linearly equivalent, the fatigue propagation path of the tooth root crack is calculated and verified by the fatigue bending test machine, The results show that the error between the test and simulation results is small and within the trusted range.

By establishing several spur gears with different transition fillet radii, Wan Guoxin et al. Studied that the root crack propagation is affected by the root transition fillet radius. The results show that the root crack propagation trend basically does not change with the change of the transition fillet radius. When the initial crack length is the same, the root crack propagation rate decreases with the increase of the transition fillet radius, The corresponding gear fatigue life will be longer.