College - Author 1
College of Engineering
Department - Author 1
Mechanical Engineering Department
Degree Name - Author 1
BS in Mechanical Engineering
College - Author 2
College of Engineering
Department - Author 2
Mechanical Engineering Department
Degree - Author 2
BS in Mechanical Engineering
College - Author 3
College of Engineering
Department - Author 3
Mechanical Engineering Department
Degree - Author 3
BS in Mechanical Engineering
College - Author 4
College of Engineering
Department - Author 4
Mechanical Engineering Department
Degree - Author 4
BS in Mechanical Engineering
Date
3-2025
Primary Advisor
John Fabijanic, College of Engineering, Mechanical Engineering Department
Abstract/Summary
Hub motors are compact electric motors mounted directly on each outboard wheel hub. Utilized in Formula SAE and Formula Student vehicles, this configuration offers several advantages over traditional drivetrains, including packaging optimization within the chassis, vehicle traction, and improved efficiency. Although hub motors are not yet common in 4WD vehicles, they are being explored for use in EVs and may become more common in the future. Every year, Cal Poly Racing FSAE designs and builds a formula-style race car. To improve drivetrain performance, the team is investigating the achievability of a hub motor 4WD drivetrain, requiring extensive research, development, and testing. This project focuses on designing a planetary gearbox and its requisite housing for integration with a hub motor 4WD system. The team has developed a novel suspension and drivetrain upright design to accommodate this system and evaluate its performance before full vehicle integration.
The planetary gearbox is derived from pervious Cal Poly Racing Formula upright designs, utilizing their trademarks of in-house manufacturing, requirements driven design. The assembly features 3 component compound gear sets, a ring gear, and sun gear. Additionally, the upright has been adapted to support the AMK hub motor with mounting features on the upright for an adapter plate which will support both the AMK hub motor and potential a cooling jacket. The hub was also revised to accommodate the gearbox structures while maintaining its signature features such as mounting face for the OZ magnesium center lock wheels as well as brake rotors and hub bearing seat.
The gear fatigue analysis was conducted using AGMA standards, supported by an interactive spreadsheet to evaluate design trends and their impact on gearbox performance. COTS (Commercial off the shelf) components were used, when possible, to prioritize two main factors: (1) reduced in house manufacturing utilization and, (2) readily available components for purchase. This allowed the team to purchase both planet gears, and all gearbox hardware.
URL: https://digitalcommons.calpoly.edu/mesp/808
Included in
Applied Mechanics Commons, Computer-Aided Engineering and Design Commons, Manufacturing Commons, Other Engineering Commons, Other Materials Science and Engineering Commons, Other Mechanical Engineering Commons, Structural Engineering Commons