Mulugeta Habtemariam (PhD)Natenael Fantaye2024-07-312024-07-312023-06https://etd.aau.edu.et/handle/123456789/3349This thesis is about the design of a novel mechanism that will be used in tire repair shops for installing/removing all wheels of a passenger car at the same time. Numerous important repair activities in such shops require all wheel removal. Such activities include all-tire replacement, tire rotation, wheel balancing, wheel alignment and associated suspension repair and brake inspection and service. The work technicians perform to accomplish such activities, although assisted by modern tools and equipment still requires manual work as there is lack of machine or equipment for simultaneous all wheel removal/installation. Currently, technicians that work in tire repair shops are exposed to various musculoskeletal injuries such as strains, sprains and overuse injuries from manual activities such as lifting and maneuvering of wheels, repetitive motion such during work having to work and dirty and noisy environment. The methodology followed includes identifying the functions of the device to be, decomposing them to sub functions, generating alternative concepts to meet the decomposed functions and embodiment design of components assemblies and modules. Part of the resulting overall mechanism is a symmetric 16-bar mechanism that performs the wheel-positioning task. This mechanism required a special attention because its motion is complex. Therefore, as a graduate-level work, this thesis rigorously analyzes the motion of every link in this particular mechanism and every joint that connects the links by using specialized kinematic and dynamic multibody simulation process. The results of the simulation part are position, velocity, acceleration and joint force values – data critically important for further design decisions. Results of the synthesis part is geometric shapes and dimensions of 31 major components and 5 major modules that create the overall mechanism. Geometry and dimension of every component, how they assemble, and their relative motion with respect to one another is thoroughly worked out to the point that further steps of the design process (i.e. detail design) have been reduced into a routine engineering task of sizing cross sections of components and selecting materials to prevent component failure during service. In conclusion, the resulting design solution enables simultaneous all-wheel removal/installation without a need for manual work in the process thereby removing the problems on technicians mentioned above. Also, the complex 16-bar mechanism’s motion is fully characterized by determining all motion parameters that describe its motion. More importantly, significant dynamic forces that result from accelerating masses of the links are determined exhaustively through multibody simulation. Having these force data is crucial to further steps in the design process as these forces must be taken into consideration in subsequent stress and deflection analyses.en-USmechanism designlinkage synthesiskinematic and dynamic simulation of mechanismsThesis