Use of Polylactic Acid (PLA) Material for Asymmetric Spur Gear Manufactured by 3-D Printing

Abstract

If large and small pressure angles are considered for the drive and coast side profile of the gear tooth, then these gears are known as asymmetric gears. The two profiles of gear tooth are performing different functions for most gear drives. The one side carrying higher workload than the other. The Moto of designing asymmetric gear enables to increase load capacity, weight reduction, and vibration level. The coast profile is unloaded or very lightly loaded during operating the drive for given time period. Asymmetry of the tooth increases the contact ratio beyond the conventional gears’ limits. One of the important advantage of asymmetric gears is reduction of contact stress on the drive flanks, resulting in higher load capacity. Such types of benefits of asymmetric gears are well known. In this work, asymmetric gear is designed, fabricated (by using 3-D printing method), and result obtained of analysis of the gear tooth (by using ANSYS software) and result obtained by experimentation have compared. By observing properties of different material I have selected the polylactic acid (PLA) for this work. From the comparison, it is concluded that the bending load carrying capacity of the spur gear is improved by using asymmetric teeth. Also it is noticed that the 3-D printing manufacturing method improves the strength of the gear.