DESIGN SPACE APPROACH FOR OBTAINING AN OPTIMIZED GEAR PAIR

Abstract

The work presented in this dissertation deals with the elaborate design of spur and helical gear and optimization of a helical gear set. The gear-set so produced can further be used to result into the smallest size of a gear-box which could favourably be used in many engineering applications. Attention is focused upon reducing the volume of the gear-set and the stresses are calculated keeping into consideration the various critical points where the stress intensity is dominant in nature. Before proceedifig to the actual design and optimization aspect, a brief review is done on the work of similar nature that has been done by experimentalists and designers in the past. In case of spur gears the objective function to be minimized was center to center distance subject to constraints on bending stresses, contact stresses and involute interference, standard gear tooth geometry was considered. Literature survey indicates that a lot of work has been done in this direction in case of spur gears but not much work has been reported on the design of compact helical gear sets. The volume (or weight) of the pinion is considered as the objective function to be minimized. Input parameters for the optimization are power to be transmitted, gear ratio, pinion input speed, normal pressure angle, helix angle, material parameters, axial contact ratio required. In the process use is made of both the conventional trend as well as the modern trends. After having taken the input parameters, a full depth system of gear dimensions and a set of standard modules is selected along with