Dynamics Performance Analysis, Parameters Optimization And Proof For Transplanting Mechanism With Planetary Elliptic Gears

Mechanization of rice-transplanting was a main measure to improve rice-transplanting efficiency and lessen the farmers' labor intensity. If the mechanization level could be improved by 1% in our country, the rice yield would be increased 375 million kilogram per year. However, the rate of rice-transplanting by machine was at a low level, only 2.8 percent in our country at present. It was mainly due to the low reliability of the rice transplanter produced in our country. Moreover, the price of foreign high-speed rice transplanter was high and they could not fit the high rice seedlings of the autumn season in the south of China. Consequently, it was imperative under the situation to develop high-speed transplanter suitable for our country. Transplanting mechanism was the primary part of a transplanter. Its performance would directly affect the efficiency and the quality of rice seedlings transplanting. Therefore, the research in transplanting mechanism is worthy and significant for the development of high-speed transplanter in our country.Rotary-type transplanting mechanism of high-speed transplanter, with a transplant rate of 400-600 times per minute, represented the developing trend in the future. Funded by the National Natural Sciences Foundation of China, Prof. Zhao Yun of Zhejiang University had invented 5 rotary-type transplanting mechanisms. All of them could meet the demands of locus and pose (angle of seedling-separating and angle of seedling-pushing) of rice-transplanting. But the dynamics characteristics of these mechanisms had not been further studied yet. The aim of this research was to study the dynamics characteristics of the mechanism with planetary elliptic gears, establish the optimized models and obtain the optimal parameters of this type mechanism. The contents and results of the research were listed as follows.1) The principles of various rotary-type transplanting mechanisms of high-speed rice transplanter had been studied, and the subjects for further research-- studying their dynamics characteristics to improve their dynamics performance and further to enhance the efficiency were put forward. An innovative idea of two-stage-optimization for dynamics analysis was presented in the paper. The creativity of the idea was that the kinematics optimization (first stage optimization) results were the constraint for dynamics optimization (the second stage optimization). By two-stage-optimization, the mechanism made according to the optimal parameters could not only meet the requirements of kinematics, but also possesses optimal dynamics performance.2) Some rules and approaches for kinematics and dynamics analysis of transplanting mechanism withplanetary elliptic gears were brought forward. Following these rules and approaches, the mechanism analysis working would be simplified and some errors would be avoided. The methods for finding unique solution of inverse trigonometric functions were discussed. The differential equations of rigid body compound motion in analytical form were derived. The approach to solve dynamics equations one by one and corresponding means to analyze drive force were submitted, which was the basis for further study on kinematics and dynamics of the mechanism.3) Kinematics characteristics of transplanting mechanism with planetary elliptic gears were analyzed, and its mathematical models were established, which were verified by high-speed Video Tape Recorder.4) Based on the kinematics mathematical models, a system of human-computer interactions in collaboration was set up. And interactive optimization software was programmed with Visual Basic 6.0. Optimal parameters of transplanting mechanism with planetary elliptic gears which could meet the demands of rice-transplanting were obtained by this system, namely the first stage optimization.5) Dynamics characteristics of transplanting mechanism with planetary elliptic gears were analyzed, and its mathematical models were established. During dynamics analyzing, the effect of see...