As a sophomore, I designed the rear gearbox/transfer case of the car. This serves as the final (fixed) reduction of the drivetrain, between the CVT and rear axles. With our loaded half-shaft rear suspension layout, it must withstand suspension forces of ~3800 lbf from the rear axles and transfer it to the frame. It also contains the 2WD/4WD shifter mechanism and a set of bevel gears to send power to our front drivetrain.

Even after increasing the footprint to accommodate a new, off-center propshaft layout, I reduced the weight by over 6 lbs compared to the previous year.

The gears were optimized by designing to an aggressive 5-hour lifespan using a torque-speed load spectra collected from on-car rear axle strain gauges in past endurance races. The tooth geometry analysis was performed in KISSSoft, and an Ansys model was used to analyze gear webbing geometry.

Ansys models of each of the five shafts in the transfer case were independently created, applying loads from the gears, CVT, and the suspension loads from the rear axles. The loads on the bearings were probed and then used to create a 20-scenario assembly-level study on the case using Ansys.