Effects of Addendum Modification on Bending Fatigue Strength of Spur Gears : 2nd Report, Casehardened Gears

抄録

Load carrying capacity of gears for tooth breakage often poses a critical problem especially in casehardened gears. The present paper describes a study into the effect of addendum modification on bending fatigue strength of casehardened spur gears. Analysis is made regarding the effects of addendum modification on the true stresses at the root fillet in connection with the worst loading point and also on the bending fatigue strength of gear tooth. Bending fatigue strength of casehardened gears can be improved considerably by selecting the proper amount of addendum modification. Addendum modification factor B_x for bending strength is derived from the analytical and experimental results and the bending fatigue strength of profile shifted gears can be estimated with fairly high accuracy, by introducing this factor into the strength design of gears.