Rigid Logged Coupling: An Improved Coupling with Less Material and Low-Stress Concentration

Abstract

The paper is about a new coupling design that can be used to connect two shafts in the same line without any axial or angular misalignment. The goals of the new design are to reduce the amount of material required to produce other couplings and reduce the chances of failure due to different stress distribution patterns. Rigid flanged coupling is used as a reference for comparison. The design consists of mainly three parts body, pins and logs (strips of metal used to connect the body). The holes are done on outer surfaces of the hexagonal or a square prism of each body while one surface of each body faces each other. The logs are used to join the two bodies with the help of pins in the holes. The coupling is designed using Autodesk Fusion 360. Proper mathematical analysis of the couplings is done to get the difference in the material used. This design can be used to connect both, shafts with the same diameter or shafts with different diameters. The design has less stress concentration around holes and in whole design in general and is similar in the manufacturing process as the presently available couplings. For the safety of the operator or user, the coupling is covered with a protective case to avoid the failed parts (if any) to hit the operator or the user. The dimensions are found using stress analysis and considering the modes of failure for each section of the part. Shear and tensile failure have been considered at the parts of the assembly. The bending effect has also been considered for parts wherever adequate. The stress analysis results have also been found out using Autodesk Fusion 360. To observe the effects and results of stress analysis, similar working conditions have been simulated with the coupling designed in Autodesk Fusion 360.