Contact stress of helical gear in heavy truck transmission

In view of the poor working conditions and large load bearing of the transmission gear of a heavy truck, which is prone to the impact of meshing in and out and sudden load change, resulting in the increase of vibration and noise and the reduction of transmission accuracy and bearing capacity, the static and dynamic contact analysis of the meshing process of the transmission helical gear is carried out by using the finite element analysis software ANSYS and ANSYS-DYNA; The effects of different backlash and stiffness of helical gear support shaft on the dynamic contact stress of helical gear are discussed; In order to improve the stress concentration of helical gear in the meshing process, the effects of different modification methods on the contact stress of helical gear are compared and analyzed, which lays a foundation for the design of transmission with low noise, stable transmission and large bearing capacity.

① Parametric modeling of involute helical gear model.

Based on the principle of gear meshing, the tooth profile and helix equation of involute gear are deduced, using ug4 0 software for parametric modeling and gear pair model assembly of involute helical gears with different geometric parameters, so as to provide a solid model for the next contact finite element analysis.

② The error of contact calculation between local tooth model and full tooth model is compared and analyzed.

In order to save the simulation cost and improve the analysis efficiency, four common local tooth and full tooth finite element analysis models with and without flange are established, and the contact calculation errors between different local models and full tooth models of helical gear are compared.

③ Mesh generation of helical gear in HyperMesh.

Mesh the helical gear pair with HyperMesh software to obtain a high-quality mesh for contact analysis in ANSYS and ANSYS / LS-DYNA software.

④ Finite element analysis of static contact stress of involute helical gear.

Based on Hertz contact theory, the nonlinear finite element static simulation of helical gear pair is carried out by using ANSYS software to simulate and calculate the size and distribution of contact stress in the meshing process of gear pair.

⑤ Finite element analysis of dynamic contact stress of involute helical gear.

The nonlinear contact dynamic simulation of involute helical gear pair is carried out by using ANSYS / LS-DYNA display dynamic finite element analysis software; The dynamic contact simulation of gear models with different backlash and different support shaft stiffness is carried out to further study the influence of backlash and support shaft stiffness on dynamic contact stress.

⑥ Gear modification of involute helical gear.

According to the distribution of contact stress and the improvement of stress concentration, the influence of different modification methods on the contact stress of helical gear is compared and analyzed. Through the modification of helical gear, the problem that the strength of helical gear does not meet the requirements in the dynamic contact analysis of helical gear is solved.