Effects of addendum modification on root stress in involute spur gears

Abstract

A study into the effects of addendum modification on root stress in involute spur gears with various pressure angles are presented in this project work. The range of addendum modification co-efficient is taken from negative value to positive value through zero by considering both the upper limit(peaking limit) and the lower limit (undercutting limit). The root stress factor is found out for various loading positions. The variation of root stress factor with addendum modification co-efficient is shown when only the driving gear is modified. A study into the effects of addendum modification on root stress using mathematical formulation as well as finite element analysis when both the driver and follower are modified at the same time also for different gear ratios. The value of root stress factor decreases with an increasing addendum modification coefficient when only the driver is modified. The root stress factor also decreases when pressure angle is increased. The root stress factor is further decreased when both the driver and follower are modified at the same time. The root stress factor decreases further as the gear ratio increases.