Parametric Study of Addendum Modification on Helical Gear Tooth Root Stress using Finite Element Analysis

Abstract

This study employs two-dimensional finite element analysis (FEA) to investigate the stresses at various points of helical gear teeth, including Von-Mises stress, principal stresses, maximum shear stress and normal stress calculations of external cylindrical gears with parallel axes. Initially, single involute symmetric helical gear tooth profiles with increasing positive addendum modification were modelled in Solid Edge ST5. The gear tooth geometry files were then imported to ANSYS 19 platform for static structural analysis. Three paths and six locations were identified for plane stress analysis. Path-1 was created on the clearance circle, path-2 on the pitch circle and path-3 on the addendum circle of the gear. The finite element model in ANSYS 19 was subjected to boundary conditions and results were obtained on the different paths and locations. The impact of addendum modification coefficient (AMC) on the tooth root, pitch point and tooth tip of an external cylindrical gear with parallel axes was explored and all stress components of addendum-modified gears were compared to a standard helical gear. The findings indicate that Von-Mises stress, principal stresses and shear stresses decrease with an increase in addendum modification on path-1, while they increase with an increase in addendum modification on path-2 and path-3. The study also highlights the importance of selecting an appropriate AMC to balance the strength of helical gear teeth with a smaller number of teeth.