Evaluation of Bending Fatigue Testing of Austempered Ductile Iron Spur Gears

Abstract

An experimental evaluation of bending fatigue strength for austempered ductile iron (ADI) spur gears wasperformed using a Zwick fatigue tester. The gear material was manufactured using vertical continuous casting,resulting in the radius of the graphite grains being smaller. The stress–number of cycles curve (S–N curve)for the bending fatigue strength of the ADI spur gears thus manufactured, without any specific surfacetreatments, was obtained using post-processing software. It was observed that when the reliability was 50%,the allowable root stress was 610 MPa. was calculated using an analytical method as well as the finiteelement method, and the difference between the values calculated using the two methods is only 7%. Thisstudy provides a reliable basis to rate the reliability design of small gearboxes in automation in the future.