Front suspension design for an electric delivery vehicle

The Paxster EDV is a small Norwegian electric vehicle for delivery of mail and parcels. It is used by a number of companies, including the Norwegian Postal Service. The company wants to improve their front suspension, this wish is the basis of the thesis. Several suspension types are used in the automotive industry. They all have different advantages and disadvantages making them more or less suited for different use cases. The suspension types are often split into independent and not independent suspensions, with various sub-categories. Typical examples of independent suspensions types are double wishbone and MacPherson setups. Dependent suspensions generally connect the two wheels with a solid axle, letting the wheels influence each other. Companies often develop the base MacPherson or double wishbone concepts further by adding elements to increase control. Paxster EDV currently utilizes a standard type of double wishbones. The system is easy to use but is still somewhat complex compared to a MacPherson setup. Through discussions with Paxster, a choice of either an improved double wishbone setup or a MacPherson setup was deemed appropriate. This minimizes the development cost, as both suspension types are common and well known. The Paxster EDV is a utility vehicle that needs to be able to hit an aggressive price point, this rules out complex hi-per struts, active suspension components and other more complex systems. The overall goals of the project were to improve the driving characteristics, lower cost and increase the free lateral space. The final product is an improved front suspension setup, specifically for the Paxster EDV, utilizing mostly standard components, except for the wishbone, steering bracket and the need to modify the chassis mounting points. The setup offers improved driving characteristics in several areas, for example by almost eliminating bump steer, a lower caster angle and more optimal negative camber gain during bump. The suspension system also offers lower complexity and cost due to fewer parts, as well as offering more free lateral space than the current solution . The wishbone exceeds the goals for strength and is designed to leverage welding, bending and cutting extrusions and sheet metal, a method Paxster already utilizes to a large extent