Design And Dynamic Stability Analysis Of Tiller Rotary Knife

China’s Micro farming machine is the main way to produce imitation of foreign products in shape, not inherent in the more in-depth understanding, therefore, the existing manufacturing mode in our country can not make up for the material properties, heat treatment process, the design criteria and standards and other aspects of the gap with foreign countries. Put forward a new structure design scheme considering the above problems, the dual drive micro tillage machine. In order to solve the problem of soil and roots of friction fatigue and vibration impact of the rotary blade and tip resistance is caused by the failure of the rotational symmetry, six blade knife for the strength evaluation and its structure was improved 5 times by using the finite element software, and then the five kinds of improved structure numerical model was set up, the numerical analysis of the static and modal of the rotary blade, the final optimal harmonic response analysis. The analysis results show that static strength, with the optimization of rotary blade structure improvement of the maximum stress concentration and the maximum deformation decreased significantly. The modal analysis results also show that the third optimization, 3 kinds of improved arc rotary blade natural frequencies are increased in the 100 Hz and split the work frequency. Through the comparative analysis of five kinds of optimization of rotary symmetrical curved blade wheel round rotary blade improved structure strength, natural frequency, vibration mode and dynamic stability. Rotary blade type of stress concentration is very small, the natural frequency is very high, can improve the fatigue life characteristics, good wear resistance and long service life etc.. If you do not consider the effects of the eccentricity ratio, in the frequency range of arc rotary blade vibration and resonance phenomenon does not appear. The results of the harmonic response analysis showed that the main vibration direction, the flywheel rotation symmetric curved blade angle of the rotary blade is basically the same as in X, Y and Z direction, the displacement response is small and the design of the rotary blade dynamic response performance can meet the requirements, well away from the resonance phenomenon, meet the micro farming machine efficiency. Rotary blade of harmonic response analysis and modal analysis results are in agreement with the results, on the one hand proves the correctness of the analysis results, on the other hand, the structure transformation of the rotary blade provides a theoretical basis.