Summary: | 博士 === 國立成功大學 === 機械工程學系碩博士班 === 96 === Mechanisms with multiple topological structures during the operation process are called mechanisms with variable topologies (MVTs), and their corresponding kinematic chains are called variable chains. The kinematic joints whose types and/or motion orientations are changeable during the operation process of an MVT are called variable joints. The MVTs are usually designed for satisfying multiple design requirements. This work presents a systematic design methodology for MVTs and determines the variability configurations of mechanisms subject to the design requirements at each stag. First, locutions of mechanisms with multiple configurations including kinematotropic, metamorphic, discontinuously movable mechanisms, and MVTs are introduced. Then, the topological characteristics of variable joints subject to input motions are investigated. The operation as well as its principles are defined, and the concept of mapping functions of variable joints is provided. A mapping function method is provided to describe the topological characteristics of mechanisms and to determine the relationships of mechanism configurations between different stages. Moreover, fundamental synthesizing corollaries are established. Then, the concept of the simplified unified graph that represents topological changes in an MVT is used to address the configuration of MVTs. A sawing mechanism and a mechanical lock with variable passwords are exemplified to analyze their topological characteristics and configuration transformations of MVTs. Finally, according to the fundamental concepts, simplified unified graph, coordinate sequence, and mobility criterion at each stage, a design methodology is proposed for the configuration synthesis of MVTs. A mechanical lock with invariable passwords, a sawing mechanism, and a mechanical lock with variable passwords are exemplified to verify the feasibility of the design methodology. And, one new mechanical lock with invariable passwords, twenty-three new sawing mechanisms, and five new mechanical locks with variable passwords are obtained.
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