A STUDY ON AN OPTIMIZED DESIGN OF A HELICAL GEAR PAIR

Abstract

The work presented in this dissertation deals with the optimization of a non-standard helical gear set. Attention is focused upon reducing the volume of a gear set subjected to constraints on bending stress, pitting stress and involute interference. Before proceeding to the actual design and optimization . aspect, a brief review is done on the work of similar nature that was done by experimentalists and. designers in the past. The review indicates that precise gear-ratio specifications often make it difficult or even impossible, to produce a workable planetary gear combination . with standard- gears. This is particularly true where space limitations must also be considered. Special centre distance, volume (or weight) or gear ratios of ordinary gear combinations are equally impossible with standard gears. Non-standard gears can overcome such limitations. A lot of work has been done in case of standard gears but no such work has been reported on the optimization of Non-standard helical gear pairs. The present work is directed towards the optimization of a non-standard helical gear pair. The non-standard gears are generated through shifting of the cutter profile, which depends on the input parameters. The two different systems namely So-gearing and S-gearing which are normally used in non-standard gearing are undertaken in this work. A graphical optimization process is employed where in the module and the number of teeth on the pinion is spread along the two mutually perpendicular axes and the constraint equations are plotted on a log-log scale. The design space so