Analysis And Synthesis On Type And Configuration Of Variable Degree Of Freedom Mechanism

The variable degree of freedom mechanism is a kind of special mechanism that the mechanism's degree of freedom can be changed by its structural constraints or systematic damp constraints in the moving course, and has certain motive regulation, thus this mechanism can realize different functions. The advance of this mechanism not only brought vitality and vigor to traditional mechanisms but also enriched the conception of traditional mechanisms and the method of mechanism design. According to different requirements, the variable degree of freedom mechanism can change its configuration in its moving process to adapt various missions and complete the function such as safe protection, order action, balance force etc. If these functions are completed by the conventional mechanism, the design will be more or very complex. So there are amplitude applications in some special realms of modern mechanical transmission.According to the basic theories of planar mechanism, the forming methods of the variable degree of freedom mechanism and the control method of the freedom are analyzed, concluded the functions and specific applications of the variable degree of freedom mechanism. To study and analyze other different types of the variable degree of freedom mechanism, such as, transformation mechanism, compliant mechanism, metamorphic mechanism and generalized variable structure linkage, the investigation broadens the field for researching variable degree of freedom mechanism.The configuration transformation was described to the process of mobility that can be changed in variable degree of freedom mechanism by topological theory. Respectively, the brake mechanism, the steel automatic clamp and sever mechanism's structures before and after their configuration transformation were analyzed and compared by the method of matrix transformation and matrix removing ranks, and the influencing rules of structural change of the kinematical chain were found. The structural characteristics of the variable degree of freedom mechanism were revealed. On the basis, the structural synthesis of aircraft loading gear mechanism was studied, and the correctness of the consolidated results was verified.At last, the configuration's degree of freedom, kinematics and force of the rolled steel dimension confirmed mechanism are analyzed. The recurrence formula between kinematics variables which exist in two adjacent configurations is established and the kinematics simulation is analyzed for this mechanism. The research result provided the theory basis for researching a series of issues about variable degree of freedom mechanism such as the intensity of various parts, mechanical balance and mechanical vibration etc.