Design and Fabrication of a Novel Corner Wheel Module for Urban Vehicles

Abstract

This thesis proposes a new design of corner wheel modules for narrow vehicles. Independent corner wheel modules with integrated powertrain, suspension, steering, and camber mechanisms combined with x-by-wire technology can replace engines, mechanical linkages, and drive shafts in vehicles. The integration of such components in the corner module creates extra room that can be used for passenger comfort. The proposed module is especially appropriate for small and narrow vehicles where packaging of all vehicle subsystems is a demanding task. It also significantly simplifies the complex chassis design and assembly process of vehicles. The new concept introduced in this thesis utilizes a four-bar linkage as the steering mechanism for the first time. This corner module also incorporates another four-bar mechanism to provide active camber control for the wheel. It is shown how an active camber control considerably improves the rollover threshold of narrow vehicles. The combination of these two four-bar mechanisms results in a virtual kingpin axis that provides stability for the chassis system. This approach results in a highly compact design for the corner module that can be integrated into narrow vehicles. The feasibility of the kinematic design, mechanical design, and stress analysis is confirmed by fabricating a full sized prototype. This prototype was tested in the laboratory environment and verified the simulation results presented in this thesis. The prototype also showed that the new design is easy to assemble for manufacturing purposes and more importantly this module can easily be maintained during its life time.