Impact of Fillet Radius on Mesh Stiffness and Performance of Polyoxymethylene (POM) Spur Gears: A Parametric Numerical Study

Abstract The growing demand for lightweight, low noise polymer gears in high performance applications requires innovative design strategies to enhance their load bearing capacity. This study investigates the influence of fillet radius optimisation on the gear mesh stiffness (GMS) of polyoxymethylene (POM) spur gears, addressing critical gaps in polymer gear design. A combined finite element analysis (FEA) and parametric approach is employed to quantify the interplay between geometric modifications and mechanical performance. Using ABAQUS, different gear models are developed with varying fillet radii (0.5, 0.76, and 1.0 mm). Quasi Static structural analyses demonstrate that increasing fillet radius reduces stress concentrations at the tooth root, decreases the addendum tooth displacement by up to 6.16%, and enhances structural behaviour. A novel position dependent power law extrapolation method is introduced to predict GMS for untested fillet radii with less than 1% error compared to FEA results. This work provides actionable insights for designing efficient POM gears in applications such as electric vehicles and robotics, where weight reduction and mechanical reliability are paramount.