MIE.46 – Custom Baja Continuous Variable Transmission

• Keenan Brunner
• Fabricio Gomez
• Het Thakore
• Hannah Thiel
• Howard Tseng
• Long Vuong

For this project the team went through the design process of creating a custom Continuously Variable Transmission (CVT) along with a ventilated cover for a SAE Collegiate Design Series off-road vehicle used in SAE sanctioned Baja competitions. To create this CVT and the new ventilated CVT Cover the group went through the engineering design process which included multiple design ideas, a Solidworks models, ANSYS simulations, and validation evaluations. Briefly the design process entailed preliminary research of established CVT designs which was subsequently used in conjunction with the vehicle parameters and project description to create tools to organize functional analysis/concept generation in the form of objective tree and function means tree. From project description the CVT will connect the primary power source, the Kohler CH440 engine, and the transfer element, a sprocket and chain system. The current problems the Baja vehicle experiences with standard CVTs are that they overheat easily and have belt slippage. To fully design this CVT, the group created a custom electrically controlled primary clutch to be used in series with an off-the-shelf secondary clutch, which will allow for more precise changes from low to high gear. The group also created a well-ventilated CVT cover made of aluminum with a directional hose to prevent overheating. The final design utilizes a rocker-arm that actuates with an electric linear actuator. The linear actuator will use a push-bar to move the thrust bearing housing of the primary clutch to rotate the sheeve and allow linear travel. The new electrically controlled CVT is planned to be used on the SAE 2023-24 Baja vehicle for their second-generation four-wheel drive system.