Concept design of a portal gear reduction upright for F150 Raptor

Abstract

When modifying cars for highland expeditions it is crucial to lower the gear ratio to compensate for the increased diameter of the bigger tires typically used in these cars. The most common solution is to change the axle ratio for ring and pinion, but the downside to this solution is it increases the torque in all components downstream of the ring and pinion, including the ring and pinion system itself. To avoid this a portal gear reduction system can be used instead. In this solution the gearing is located at the wheel-hub so all components upstream of the portal do not see additional torque. At the same time it can be used to increase ground clearance. This solution exists for many types of cars, but not for the gen 3 F150 Raptor. This is a viable car to modify for highland expeditions and therefore the objective is to determine if this approach to modify the F150 Raptor for highland expeditions is feasible by making a concept design for the front axle. Appropriate gear reduction for the car and load on the system were found with the use of a traction model. A gear concept was designed which meet the requirements and load according to the AGMA standard. The solution was designed to t into the space of a 17" wheel, using Inventor and 3d-models for the gen 3 F150 Raptor, tire and wheel and other components. The conclusion is that a portal gear is a feasible solution for the F150 Raptor and can improve the performance in challenging circumstances. The gear system satisfed the driving and load requirements, with 1.41:1 gear reduction at the wheel-hub. The concept design t into the wheel but the upright design requires further analysis.Keywords / Efnisord: Ford, F150, Raptor, Portal, Gears, AGMA, Traction, Modi cation, Expeditions Niðurgírun, Gírar, Jeppi