Design Modification of Bending Strength of Spur Gear in Worst Loading Conditions with Material Change

Abstract

Spur gears are extensively used in power transmission systems due to their simple geometry, efficient torque transfer capability, and reliable operational performance. However, under severe loading conditions, bending stress concentration at the tooth root becomes a major factor influencing gear failure and structural durability. This study presents the design modification and bending strength evaluation of a spur pinion under worst loading conditions through material substitution between steel and aluminium alloy. Analytical design calculations were performed based on predefined geometric parameters including module, number of teeth, face width, and operating pressure. A three-dimensional CAD model was developed using Solid Edge ST7 and imported into ANSYS Workbench for finite element analysis. Comparative evaluation was conducted to assess equivalent stress, deformation characteristics, weight reduction, and operational suitability. The simulation results revealed that aluminium alloy produced nearly equivalent stress values compared with steel while significantly reducing component weight. Although steel exhibited lower deformation and higher stiffness, aluminium demonstrated acceptable structural performance with improved weight efficiency and corrosion resistance. The findings indicate that aluminium alloy can serve as an effective lightweight alternative for pneumatic actuator spur pinion applications while maintaining safe operating conditions.