Research On Vertical Axial Flow Threshing Device And Technology Of Wheat Harvester

The threshing device is the core component of the wheat harvester.Its threshing separation performance directly determines the harvesting quality of wheat.The study of the theory and technology of threshing wheat separation is the key to improve the harvest operating performance of the wheat combine harvester.This project aims at solving the problems of low feeding amount,low efficiency,serious losses of existing wheat harvesters.It also develops and studies high-input,high-efficiency,low-loss vertical flow wheat threshing devices and performs EDEM simulations and field simulations.The experiment showed that the best working parameters of the vertical flow wheat threshing device during wheat harvesting are as follows;This will improve the technical level of the vertical flow wheat threshing device,accelerate the upgrading of products,and promote the progress of China’s agricultural harvesting machinery industry have important significance.The main research work includes the following aspects:(1)According to the current trend of the development of the wheat harvester to high-power efficient threshing,the overall structure of the vertical flow wheat threshing device and the main working components:feed screw,threshing element,concave plate,roller cover and so on were calculated and designed;The theoretical analysis of the process of feeding wheat spirally and feeding wheat in the longitudinal flow threshing drum was carried out,which provided a theoretical basis and reference for the design of feeding spiral.(2)A vertical-flow wheat threshing device was developed.The main structural parameters of the device,including feed volume,drum rotation speed,and threshing clearance,were analyzed by single factors,and the influence of these parameters on the threshing effect and power consumption was determined.It can be known from the test results that the total power consumption and grain loss of the vertical flow wheat threshing device are affected by such factors as the feeding amount of the drum,the rotation speed of the drum,the spacing of the struts,the threshing gap,and the ratio of grass and corn.(3)Based on the discrete element method,a discrete element model of the material object was established,and the movement process of the wheat mixture material in the threshing device was simulated using the EDEM simulation software as a platform.Through observing the mixed material in the model,it was found that the device was very good at transporting the wheat mixture.The variation of the average speed and displacement of the grain in the device over time was analyzed.(4)Selecting the rotating speed,threshing clearance and drum inclination angle as the experimental factors affecting the threshing performance of the vertical flow wheat threshing device,the multi-factors test was performed on the vertical flow threshing device to find out the main factors and influence the impurity rate of the device.The correlation between the loss rate performance indicators and the significant degree of influence of various factors on the performance indicators are analyzed;the test results show that:the vertical flow wheat threshing device has a rotating speed of 800r/min,a threshing gap of15mm,and a drum inclination of 8~o Under the parameters,the average loss rate of wheat harvest was 0.29%and the average impurity content was 0.11%.