| The Crank-group driving mechanism is a new type of transmission mechanism which can realize constant rotation between multiple axes, it mainly consists of different structural styles of crank member and connecting rod truss. This mechanism has many characteristics, such as the short transmission chain, efficient production, compact formulation and easier to fabricate and so forth. However, its dynamic balance is more complicated than a single rotor or common linkage mechanism on account of unbalance quality of all components will make the running mechanism produces vibrations and noises. Cranks, motor and each drive shaft should be integrated together in dynamic balance test bed by adding counterweight or elastic element to offset unbalance amount of mechanism and reduce vibration. Until now, the literature about parallel shaft or redundant transmission system dynamic equilibrium theory and experimental study is rare, the available literatures primarily focus on single rigid or flexible rotor dynamic balancing properties, this paper made the following three aspects of research work by means of theoretical analysis and experimental verification.(1)The dynamic characteristics of crank-group mechanism was discussed in depth by utilizing linear independent vector method, angular momentum substitution method, quality moment substitution method and quality substitution method to derive the balancing condition of shaking forces and shaking moments of mechanism, regarding it as a sort of planar linkage mechanism.(2)On the basis of simulation results of dynamics analysis software for different types of virtual prototyping model of crank-group mechanism, puts forward the verification of dynamic equilibrium condition and analysis on advantage and disadvantage, the optimal dynamic balance scheme was determined. Moreover, the impact on mechanism with adding elastic components was also discussed.(3)Six Crank-group Driving Mechanism dynamic balance test table was rebuilt based on original physical testing machine during which a set of test system were bought and also designed the corresponding experimental program. The dynamic balancing theory of Crank-group Driving Mechanism was tested by comparing horizontal and vertical acceleration of fixed revolute pair of each crank before and after imposing counterweight, proposes several improvement measures about designing shortcomings in the course of doing the experiment.This thesis explained the dynamic equilibrium theory, virtual prototype simulation and experimental tests of Crank-group Driving Mechanism according to the actual operating situation. Under the premise of kinematic characteristics of mechanism are met, the machine has more ideal dynamics balance effect. It has accumulated some experiences and laid foundation for the future theoretical innovation and experimental design methods. |
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