Gear

Abstract

The invention aims to improve not only the resistance to abrasion and scoring, but also the fatigue strength against pitting and chipping, without increasing the number of steps of the manufacturing process. The tooth face 2 of the gear is smoothed by gyro polishing. In the thus smoothed tooth face 2, a multitude of microscopic recesses 3 are randomly formed by liquid honing in which microscopic hard particles are collided with the tooth surface together with liquid. By the liquid honing, a large compressive residual stress is produced on the tooth face 2. This improves not only the resistance to abrasion and scoring, but also the fatigue strength against pitting and chipping, without increasing the number of steps of the manufacturing process.

Dependencies are inferred from the claim text.