Abstract
In order to investigate the influence of peening on the fatigue life of steel gears, the steel rollers and gears cavitation shotless peened and shot peened with different conditions were fatigue-tested using a roller testing machine and a gear testing machine. The hardness and the compressive residual stress of test rollers and gears increased by these peenings. The surface roughness of those increased by the shot peening, whereas those did not increase so much by the cavitation shotless peening. In the fatigue tests, the fatigue life of most shot peened gears was as long as that of the non peend gear in this experimental range. On the other hand, the fatigue life of most cavitation shotless peened rollers and gears was longer than that of the non peend roller and gear. It follows from these that the cavitation shotless peening is good for the increase in fatigue life of steel gears, because the surface roughness does not increase so much by cavitation shotless peening.
