Means of Improving Gear Life

Author:  Dale L. Taipale
Source:  US Patent 4,167,864
Doc ID:  1979053
Year of Publication:  1979
Abstract:  
Disclosed herein is a process of compression stressing a metal workpiece having a body with a central bore so as to produce a residual compressive stress in the workpiece to increase the fatigue strength of the workpiece. The process includes the steps of forcing the workpiece onto a mandrel to induce an initial tensile stress in the body, thereafter inducing a compressive stress in the surface of the workpiece by shot blast treatment of the surface of the wokrpiece, and thereafter separating the workpiece from the mandrel to increase the compressive stress in the surface of the workpiece.