DefinePK

Abstract

Gears are machine elements used to transmit motion and power between rotating shafts by means of progressive engagements of projections. Gears have wide variety of applications. Their application varies from watches to very large mechanical units like the lifting devices and automotives. Engineering components made of composite materials find increasing applications ranging from space craft to small instruments. Overwhelming advantages such as light weight, higher dimensional stability and minimal attack by environment when compared with other ordinary mild steel gears. Modern level advanced polymer composite materials have opened a new level of soundless, lubricant free, high resilience and precision gearing in power and motion transmission. A proper understanding and prediction of gear failure is an important pre-requisite for any reliable application. In this project, a spur gear is designed using advanced modeling software (pro-engineer) and is meshed and analyzed using analysis software Abaqus 6.10 by the application of torque load. Two types of analysis are carried out using the software namely the static stress analysis and modal analysis. In static stress analysis tooth contact of a pair of spur gear system is analyzed as a body contact in three dimensional co-ordinates. The analysis consists of one loading condition to apply torque load on driving gear by constraining all degrees of freedom of driven gear. The hexagonal element model is meshed with in such a way that the elements around the gear teeth are fine and coarse at other places. The three dimensional elemental stresses and displacement magnitude are found out. Using modal analysis, the natural mode shapes and frequencies of composite gears is determined under free vibration. The interpretation of Eigen values which come from solving the system are that they represent the frequencies and corresponding mode shapes. The analysis is thus carried out making a comparison for a mild steel spur gear and carbon fibre / epoxy resin composite spur gear. The results in the variation of three dimensional stresses, displacement, frequencies and Eigen values are plotted and viability to manufacture such gears is predicted.