ELECTRONIC CONTINUOUS VARIABLE TRANSMISSION FOR BAJA RACE CAR

Abstract

The Baja race car’s mechanical CVT had two major issues that served as the primary reasons for undertaking this project. The first issue was the tedious and error-prone process of tuning the CVT. The second issue was the mechanical CVT not being properly sealed which put the components inside at a risk of damage from dirt and water. The team designed and built a prototype E-CVT for the SAE Baja Competition that would counter those issues. The E-CVT design consists of two pulleys connecting the engine and gearbox that change their diameter based on data collected from the engine. The data collection is based on the telemetry system previously designed by Baja SAE’s Electrical sub-team. By using electric motors in conjunction with sensors and microcontrollers, the E-CVT algorithmically changes the gear ratio between the engine and gearbox. The E-CVT's insulated wiring and protective casing at IP54 certification level ensures its protection from water and dirt in the off-road racing environment. The new system offers greater adjustability and increased reliability. After carrying out the acceptance tests, the E-CVT system was shown to be capable of handling overvoltage and overcurrent as well as a successful collection/sending of data to the central data collection microcontroller. The bench test of the completed E-CVT displayed the changing gears at the engine’s peak power.