Generating interchangeable 20° spur gear sets with circular fillets to increase load carrying capacity

This article presents a new spur gear 20° design that works interchangeably with the standard 20° system and achieves increased tooth bending strength and hence load carrying capacity. In this design, a circular fillet replaces the normal trochoidal fillet, yielding larger cross-sections at the tooth root and lower stress concentration. The actual working tooth profiles remain unaffected. To verify this design, a series of numerical simulations was carried out using the boundary element method (BEM), and the results were confirmed with subsequent laboratory testing.