Projeto e dimensionamento de uma caixa da câmbio com 3 velocidades para um veículo Baja SAE

Abstract

This study presents the design of a 4x4 transmission system with two forward gears and reverse, developed for a Baja SAE off-road vehicle. The motivation for this project arises from the need to update the powertrain configuration of the Baja Gralha Azul team from UTFPR - Ponta Grossa, considering the latest technical requirements of Baja SAE Brazil competitions, which mandate four-wheel drive for teams seeking qualification for international events. The main goal is to develop a robust and efficient gearbox integrated with the engine-CVT-differential assembly, capable of improving vehicle performance and reliability. The methodology adopted was based on the Integrated Product Development Process (PRODIP), including vehicle longitudinal dynamics modeling, component selection and sizing, and structural arrangement definition. The final transmission ratios of 10.5:1 for first gear and 7:1 for second gear provided significant performance improvements. The proposed system is expected to increase available tractive effort to 5000 N, representing a gain of approximately 2000 N over the previous configuration, as well as increase top speed over a 100-meter stretch from 41 km/h to 52 km/h and reduce the 30-meter acceleration time from 5.2 s to 4.35 s. The results demonstrate that the developed transmission system meets the project requirements and contributes to enhancing the competitive performance of the team, while also establishing a solid foundation for future developments, experimental validation, and structural or efficiency improvements.