| Summary: | The current diploma thesis describes the design and the development of the drivetrain system used by the UoP5e, an electric racecar which took place in Formula Student UK 2017 and FSG 2017 competitions, representing the University of Patras, and specifically the department of Mechanical and Aeronautics Engineering. Formula Student competition is an international design competition organized by the SAE International (former Society of Automotive Engineers). The concept of the competition is the design of a single seat open wheeled racecar, for a fiction manufacturing company, focused on the weekend racer. The student teams design and manufacture their own prototypes, based on rules published by the competitions. The final scoring divides into two categories, the static events which include the design presentation (150 points), the cost and manufacturing (100 points) and the business plan presentation (75 points), and the dynamic events which include acceleration (75 points), skidpad (75 points), autocross (100 points), endurance (325 points) and finally efficiency (100 points). Considering the current developments in the field of the automotive industry, the competition has created an electric racecar class, and UoP Racing has been developing electric racecars since 2012, when the change from internal combustion power units to full electric power units was decided. This diploma thesis focuses on the decision making process of the mechanical design, the development and the manufacturing of the drivetrain system of an electric racing vehicle. A drivetrain system of an electric vehicle is considered every device that produces and transfers mechanical power. It includes the electric motor, the gearbox, the differential and the transmission of power to the driven wheels of the vehicle. The drivetrain of UoP5e is comprised by a high power density electric motor [EMRAX 228 HC LC] mounted across the vehicle’s longitudinal axis, a custom-developed single speed twin-stage transaxle type gearbox, a limited slip clutch-pack differential integrated to the gearbox and a system of floating tubular steel driveshafts. The design was focused on three main characteristics the reliability of the components, the vehicle performance aspects and the economically feasible design solutions. The reliability is ensured through the structural analysis and the physical testing of each component. The vehicle performance aspects are evaluated through a self-developed acceleration performance model, coded in MATLAB. Finally the economically feasible design solutions are based in a design for manufacturing approach, meaning that every developed component’s design is carefully balanced between performance characteristics and manufacturing feasibility.
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