Study On The Dynamic Characteristics Of Screw Shaft Of Cow Dung Pickup Machine

For cow dung pick up machine in cow dung cleaning process caused by rotor instability run bigger noise and vibration problems,this article will first generation prototype rotation improvement for the rotor structure,double helical blade double throw dung as the research object,analyzes the dynamic unbalance of the rotor caused by uneven quality of the influence of support bearing,validated the rationality of the improved rotor structure.Specific work contents are as follows:? The dynamic equilibrium state of the screw shaft without random adhesion is verified and calculated.The mass,the center of mass and the overall mass and centroid of the shaft are calculated for each segment of the shaft,and the centrifugal force generated by each segment of the shaft is obtained.Using the two-sided balance method,the vector sum of the centrifugal force of each segment of the rotating shaft on the P and Q faces at the left and right ends of the rotating shaft is obtained.The results show that the screw shaft has good dynamic balance performance under ideal working conditions.?Discuss the effect of the dynamic imbalance caused by the random adhesion of the spiral shaft on the service life of the bearing.Using MATLAB software to obtain the coordinates of 10 random points on the curved surface of the rotating shaft,and calculate the coordinates of the overall centroid of the spiral rotating shaft when the attached objects are randomly adhered.The spiral shaft-bearing mechanical model is established,and the calculation formula of the radial restraining force of the bearing at both ends is derived.The range of the radial force of the bearing is determined,and the service life variation range of the bearing is finally obtained.?On the basis of static contact stress simulation analysis,the fatigue life of tapered roller bearings is analyzed by adding S-N curve of materials and Fatigue tool fatigue life analysis tools.The minimum cycle times of bearing materials are obtained,and the sensitivity of fatigue life of materials to the variation of alternating load is discussed.?The finite element model of spiral shaft was established,and the modal analysis results show that the cow manure machine can finished the picking operation smoothly.?The finite element model of the bearing supported at both ends of the helical shaft is established.The static and dynamic contact stress of tapered roller bearings are simulated by finite element method.The simulation results are compared with the results of Hertz theory and the yield limit of materials.The correctness of the simulation results is verified.It is concluded that the equivalent contact stress is within the yield limit of the material and the material will not be destroyed.On the basis of the static contact stress simulation analysis,the material S-N curve and the Fatigue tool fatigue life analysis tool were added to analyze the fatigue life of the tapered roller bearing.