This project was completed for MECH 360– Design of Mechanical Elements, at UVic. The project specifications were to design a gearbox for a small-scale ferris wheel which utilized a 0.5-5kW electric motor operating constantly at 1750 RPM, with a gearbox efficiency of 97% and a 20-year lifetime. Requirements for the project included the design of all gearbox components (gears, shafts, housing, etc.), material selection (for custom components as well as bearings and fasteners), and failure analysis of the gears. The final gearbox design featured four-stage gear reduction with spur gears mounted on parallel shafts resulting in a total gear reduction ratio of 437.5:1. The theoretical output would be 1.157kNm at 4 RPM from an input of 500W at 1750 RPM. Key design considerations included ease of maintenance, overall size and weight, and longevity. Optimization of gear size was completed to achieve the smallest gear width (minimizing overall size and weight of the unit) which met the group’s desired safety factor. The housing was designed with maintainability and longevity in mind, and as such features easy access to the gear train and acts as a lubricant reservoir for the largest gears which facilitated splash lubrication.
Among other tasks, I was responsible for the gear failure analysis. To accomplish the gear failure analysis, I wrote a MATLAB script which took in various parameters including material properties and gear contact information, and returned the minimum acceptable face width and the associated safety factors.
