| Summary: | 碩士 === 臺灣大學 === 機械工程學研究所 === 95 === A methodology based on the concept of kinematic fractionation for the revelation of kinematic characteristics and classification of geared mechanisms is presented. It is shown that structurally non-fractionated geared mechanisms can be considered as the combination of kinematic units (KUs). Each KU is considered as the basic motion transmission module inside a geared mechanism. Admissible connections of KUs are identified according to the structural characteristics of one- and two-DOF geared mechanisms of up to four KUs. Such configurations are then used to construct possible propagation paths of motion via the assignments of input and output links. Since the propagation paths can be modeled by the control block diagram problems, the kinematic relations between input and output links are formulated to gain matrices. According to the types of entities in a gain matrix, various kinematic behaviors are disclosed. The complete kinematic behavior of single KU is revealed and three gain forms of KU is basic of global gain since the geared mechanism is combination of KUs. The global gain of the mechanism is determined by three factors: the configuration decides the transmission flow at KU level, the common linkage between KUs of the mechanism limit the thin edge type of local input and output in the connection of KUs, the assignment of input, ground and output decides the thin edge type of global input and output. From the factor of global gain, there are three gain type are identified and characteristics of geared mechanism are more clear. It is believed that such kinematic characteristics can be readily transformed into the functional requirements and synthesis of geared mechanisms of up to four KUs can be accomplished much easier.
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