An Approach for Narrowing the Method of Selection of Profile Shift Coefficient for A Given Helical Gear Pair

Profile shift or Addendum modification is provided in gear teeth to avoid undercut, improve strength and running properties or adjust the centre distance. Along with this, it is generally recommended for gears with a critical number of teeth, non-standard entre distance, obtain balances specific sliding or obtain reduction in sizes. However, there is no specific ready data that advises how to use it and what value can be opted. This research work is performed to investigate the effect of addendum modification on various parameters like contact ratio, tooth root strength, specific sliding, and undercutting. A pair of helical gears with 24 teeth and 97 teeth with 20-degree pressure angle and 13.4022-degree helix angle is considered for study purposes. The results are compared with the kissSoft data, and charts are prepared to establish the selection of addendum modification parameters for both gear and pinion. As an output of this research work, a graph is produced to help in narrowing the selection of profile shift coefficient with an excel tool for performing various functions. This work was specific to the sample case, whereas the same methodology can be implemented for other pairs of gears.