Wheel Loader Rear Axle Mounting for Weld Deformations : Exploration and Evaluation of Alternative Mounting Methods

Abstract: Welded structures susceptible to weld deformations require sequent processing to allow for mounting of precision components. This thesis includes a case study of the rear axle mount on a Volvo L220 wheel loader. A product development process was deployed in order to explore and evaluate alternative mounting methods such that manufacturing cost due to sequent processing could be decreased. Analysis of the frame variations showed any new concepts has to accommodate variations of up to $\delta z=-1.24\pm3.5$ mm. The product development process found two potential concept philosophies; transferring concepts which improves upon the current concept by transferring the processing away from the frame onto smaller components that are cheaper to process, and absorbing concepts that avoids sequent processing by absorbing the frame variations altogether. The transferring concept "Custom Plate" was selected for further development. The concept is based on the principals of reverse engineering by manufacturing a custom plate from a 3D surface map of the deformed mounting surface, placed between the frame and rear axle bridge, matching the surface geometry of both entities. The concept showed no apparent critical strength issues when simulated in CATIA V5. However, the economical gain of the concept is slim and depends heavily what spaces can be allocated for additional processing machinery. Suggestions for further development of the concept are given along with a discussion of improvements outside of the system boundary of the project, such as simulation of welds and welding sequence, and collection, storing, analysis, and visualisation of data.