Experimental Research On Wear Failure Mechanism Of Spindle Hook Teeth Of Cotton Picker

Xinjiang is China’s largest cotton production area and commodity cotton base,cotton as an important economic crop in the Xinjiang region has an extremely important strategic position.Cotton picker as a large cotton harvesting equipment,because of its low picking costs and efficient picking efficiency,is widely used in China’s Xinjiang region cotton harvesting process.As the key core component of the cotton picker,the performance of the spindle directly determines the picking quality and picking efficiency of the cotton picker in the field.At the same time,spindle is also the most consumable wear parts of the cotton picker,the field operation process spindle hook teeth are prone to wear failure problem.For the picking operation process spindle hook teeth are prone to wear failure,and the mechanism of the wear failure of the hook teeth is unclear.In this thesis,cotton picker spindle is the object of study,on the basis of the mechanism of spindle operation,combining theoretical analysis and finite element simulation analysis,the mechanical behavior analysis of spindle picking cotton and collision process with cotton stalks is carried out.Through the performance test of the spindle coating and field test,the research on the wear failure mechanism of the spindle is carried out,and the change of the hook tooth wear failure of different installation positions of different kinds of spindle is compared and analyzed,characterizing the microscopic shape of wear failure of hook teeth,analyzing the cause of wear failure of hook teeth,and revealing the mechanism of wear failure of spindle during cotton picking operation in the field.The study provides a reference basis for further improving the wear failure mechanism of spindle,guiding the construction of high wear-resistant coating on the surface of spindle,and realizing the localization of the high-abrasion-resistant cotton picker spindle.The main research contents are as follows:(1)Mechanical behavior and finite element analysis of spindle during cotton picking operation.The mechanism of spindle picking operation was analyzed.the picking area is identified as the area where spindle wear is likely to occur,carry out the mechanical analysis of spindle picking and cotton colliding with cotton stalks,a simulation model of spindle picking area was established,combined finite element simulation analysis and collision simulation analysis,stress and strain distribution patterns of spindle picking and collision with cotton stalks were revealed,the dangerous parts of the spindle hook teeth that are prone to failure during the cotton picking operation and the areas where the spindle and cotton stalks are prone to collision were identified.(2)Field test of spindle and coating performance test and wear characterization method.In order to explore the reasons and the evolution process of the wear failure of the spindle hook teeth.In the experiment,different kinds of spindles were selected for field experiments,and spindle samples were obtained for field experiments at different installation heights,a test plan for micro-morphology,hardness,adhesion,phase structure,elemental composition and corrosion resistance of the spindle coating and a field test method for the characterization of spindle sample wear were formulated.(3)Testing and analysis of the coating properties on the surface of spindle.In order to explore the effect of coating properties on the wear resistance of spindle field operations,the research combined with the spindle structure parameters,and the production and characterization method of spindle samples was formulated.Scanning electron microscope,microhardness tester,coating adhesion tester,X-ray diffractometer,energy dispersive spectrometer,electrochemical workstation and other instruments were used to compare and analyze the surface cross-section micromorphology,hardness and adhesion of the spindle coating,phase structure,element composition and corrosion resistance.The results provide a reference for the analysis of wear failure changes in different types of spindle field operations.(4)Experimental study on the mechanism of wear failure of spindle hook teeth.The wear failure changes of the spindle samples obtained in the field test were characterized,and the wear area and wear width of the hook teeth were extracted to describe the wear change of the spindle hook teeth,the wear failure changes of hook teeth of different kinds of spindle and different installation heights were compared,and the wear failure appearance of spindle hook teeth was characterized,and the reasons for the wear and failure of hook tooth were analyzed,the wear failure mechanism of the spindle hook teeth in the field cotton picking operation is revealed,and it is concluded that the wear of spindle hook teeth is mainly caused by the combined effect of abrasive wear,fatigue wear and oxidation wear.