Method of Manufacturing a Gear

Author:  Hiroyoshi Tawa; Masahiko Mitsubayashi; Hideyuki Sakaue; Keisuke Kadota
Source:  US Patent 9,457,451
Doc ID:  2016050
Year of Publication:  2016
Abstract:  
The problem of the present invention involves providing a gear that has high tooth-root bending strength and for which there is no chipping of the tips of the teeth. Accordingly, the surface of the gear is carburized and the gear is strengthened by imparting residual stress, with the residual stress in the region with a surface depth of 5 um to 20 um being -1000 MPa or less, and the residual stress in the region with a surface depth of 50 um to 150 um being -1000 MPa or greater.