DESCRIPTION
This is a shaft for a theoretical power system designed to support a 70 N-m torque, cycling on and off over the course of a ten-year lifetime. This involved the design of two spur gears, keys, a 46-inch shaft of varying diameter, two bearings, and the bolts to hold the bearings down. The components were designed with a safety factor of 3, considering several static and fatigue failure methods, slopes and deflections, critical speeds, and stress concentrations.
Shaft Design
PROCESS
This was a project completed in a Mechanical Engineering Design class at Northeastern University. The process started with a simple layout and a free body diagram of the given system for static loading. Four different fatigue failure criteria were used to estimate a shaft size. This iterative process and all engineering calculations, including deflections, slopes and others, were redone after a preliminary analysis and estimate of the shaft components and possible layout of gears and bearings. Additional analysis included key design for securing the gears, selection of rolling contact bearings with given input of power to the shaft, appropriate bolts for securing the bearings, and the different gear designs. This work was then presented in a 31-page professional report.
LESSONS LEARNED
In this project I learned all of the complicated calculations and design decisions that go into a seemingly simple subsystem. I learned to apply failure analysis for many different components as well as select parts and assemble them in CAD. I also improved my teamwork and group management abilities.
