| In recent years, the cycloid ball planetary transmission is developed into a new type of precise cycloidal transmission device which uses the moving ball as the transmission medium to replace the gear tooth in traditional gear drive. The ball engages with a cycle raceway that formed by internal and external cycloidal grooves to transfer movement and power. The ball always keeps in touch with cycloidal grooves through an axial preloading device. The transmission device can eliminate the meshing pair clearance and achieve no backlash transmission. And the ball is rolling friction with low energy consumption. The meshing quantity of ball and cycloid groove is large, and the transmission efficiency is high. The cycloid ball planetary transmission is a new precise transmission device with high efficiency and energy saving.Based on the structure features and transmission principle of the cycloid ball planetary transmission, the structure types and transmission ratio of the mechanism is analyzed, and the basic structure parameters of cycloid ball reducer is designed in traditional design menthod and optimization design menthod respectively. According to the best optimal design results, the solid model is established, and the motion simulation and finite element analysis is executed. The specific works are as follows:(1)The structure type of one stage and two stage cycloid ball planetary transmission is analyzed. The transmission ratio of structure type is calculated. The example analysis of the two stage parallel combination type is carried on by selecting three sets of data. The theoretical cure equation of cycloid and the ball position equation are introduced briefly.(2)The two stage cycloid ball reducer of the type I and type IV parallel combination is selected as the research object. According to the transmission ratio,power and the related calculation formula, the basic design parameters of the cycloid ball reducer is calculated by using trandition menthod. Then based on the theory of genetic algorithm, the optimization mathematical model of the two stage cycloid ball planetary transmission is established by taking the smallest volume and the highest efficiency as multiple targets function. And the genetic algorithm program is writed in MATLAB to optimize a set of optimal structural parameters of the reducer. Making a comparision between the tradition design results, the optimization design results and the round results, a set of optimal design parameters is obtained.(3)The optimal design results are selected as the structural parameters. The overall structure of the reducer of type I and type IV parallel combination is designed, and the parametric model is established by using parametric function of Pro/E. All parts of the reducer are assembled by using the assembly function of Pro/E. The assembly model of two stage cycloid ball reducer is obtained. The solid model is provided for analysis of the following chapters.(4)The assembly model of type I and type IV parallel combination is analyzed in ADAMS to get the angle velocity and angle acceleration curve of eccentric disc and output disc. And the drive ratio is verified. Then the solid model of type I and type III parallel combination is established, and the simulation analysis is analyzed in ADAMS to get the angle velocity and angle acceleration curve of eccentric disc and output disc. And the drive ratio is verified. The rationality of structure design of two stage reducer is verified.(5)Finite element analysis of two stage cycloid ball reducer is proceeded by using Workbench. With the input shaft and the cycloid disk system as the research object, the deformation, stress distribution and contact state of the deceleration part are analyzed. Then modal analysis of the input shaft and the cycloid disk system is carried on, and the former 6 order natural frequency and main vibration type are extracted. The modal characteristics are analyzed and compared to further verity the rationality of structure design of two-stage reducer. It can also provide reference to optimize the system structure of the reducer, avoid resonance, reduce noise, improve work performance, etc. |
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