Study On Profile And Lead Modification Of Gear Coupling With Gearbox Stiffness Based On ANSYS

200,000 dwt mixing extrusion granulator brought forward higher requirements on the decreasing Gearbox. Therefore, further investigation on the tooth modification technique was of significance to enhance its load-bearing capacity and transmission stability.This paper researched on the former gear pair in the gearbox of 200,000 dwt mixing extrusion granulator, using APDL language to create parameterized gear contact model in ANSYS, combing with the integrated deformation of the tooth attained by the result of contact analysis and gearbox deformation, given the methods of calculating profile and lead modification parameters of helical gear according to the load distribution along the contact lines.First of all, according to the principle of gear meshing and on the basis of the theory of gear profile and lead modification ,a new approach on determining modification parameters by gear contact analysis was proposed.Secondly, parameterized helical FEA model was established which included gear shafts using APDL based on the involutes curve equation, the involutes curve helicoids equation and the root transition curve. The grid of the contact surface of finite element model was refined ground on derivation of the contact line equation to meet the solving precision. Then, contact anlysis mode was created and constrains and loads were applied depending on connection of parts. A complete software dealing with gear modification taking Visual Basic as a platform, SQL Server as a data carrier was developed, which could achieve all APDL programs.Then, without taking into account of deformation of gearbox, by calculating combined deformation of gear shaft using simplified method of reckoning gear shaft bending and torsional stiffness, in addition to load distribution of contact analysis result, calculation on three parameters of lead modification was performed. Similarly, three parameters of profile modification were calculated by the principle of gear meshing and integrated deformation of tooth.Then, the algorithms applying to determining modification parameters coupling with gearbox stiffness was proposed. A special unit was applied to carry out the transmission of force and displacement between gearbox and gear shaft and the gearbox stiffness matrix was gained making using of linear correlation of force and displacement on it, which helped to improve calculation efficiency. The analysis showed that gearbox stiffness had influence on tooth deformation and load distribution along contact lines, it was essential to take into account of gearbox displacement when determined modification parameters.Finally, loading distribution change of a tooth in the process of entering into meshing to ending meshing was graphically presented. The contrast showed that, proper modification effectively removed the tooth interference, reduced vibration and gear transmission noise, improved the uneven load distribution along the lead direction and raised the bearing capacity and service life.The research on the modification of helical gears in the gearbox of 200,000 dwt mixing extrusion granulator was of great value and significance for a further research of gear-driven kinematical capability.