Shot Peened Gears As Evaluated By Single Tooth Fatigue Tests

Author:  Wulpi, D. J.
Source:  International Harvester Company
Doc ID:  1956006
Year of Publication:  1956
Abstract:  
Shot peening improves the fatigue strength of gear teeth. There is generally no argument over that statement. But how much of an improvement can actually be made in the load carrying capacity? Many gears have been run in rotating tests showing that the life at a constant load is increased or that higher loads can be carried without failure. these show, in a general way, that the bending strength of the teeth is increased by shot peening. However, other types of gear failure - such as pitting, scuffing, or wear - often tend to confuse the results when tests are run at thigh loads or extended times. This makes the quantitative evaluation of shot peening quite difficult with rotating tests. Gears can fail in so many ways that it is often desireable to isolate the type of failure under study by eliminating the possibility of other types of failure.