Research And Improvement Of The Selection System Of 4LZ-1.0 Simple Combine Harvester

Southern region is the main producing area of rice in China.However,in the southern areas,the soil is so soft that the large-scale combine harvester cannot adapt to the farming environment.So it is necessary to employ simple combine harvester.However,many simple combine harvesters have the disadvantages of poor cleaning effect,poor working environment,etc.In order to solve these problems,this paper makes research on the cleaning system of 4LZ-1.0 simple combine harvester.The main conclusions are as follows:(1)First,Pro/E software was used to draw the 3D model of the 4LZ-1.0 small combine harvester.Then this paper puts forward four kinds of plans for transmission improvement,including gear type,belt type,gear box type,and motor-driven type.After considering multiple factors,including adjustability,difficulty of processing,economy,transmission efficiency and so on,it was found that the motor-driven type are the most suitable one.Then the structural parameters of the main components have been calculated.Based on multi-body dynamics theory and finite element theory,the multi-body dynamics software RecurDyn was used to simulate the work process.Finally,the meshing transmission ratio was tested.The tooth contact force,the rotation torque and the verification of the maximum equivalent stress were calculated.(2)In order to reduce the degree of accumulation at the entrance of the cylindrical screen,ANSYS Workbench's CFX module was used to simulate the wind farm to obtain a streamline diagram,wind speed cloud diagram and wind speed of vector diagram.It was found that the fluctuations and vortices in the wind farm are the main causes for stacking.Then some proposals were executed,and the fluctuations significantly reduced.(3)In order to solve the problem of high impurity rate in the screened material,the CFD-DEM coupling technology was used to simulate the material screening process.It was found that the material accumulation in the cylinder screen was an factor caused this problem.Then this paper proposed a method of installing deflectors on the inner wall of the screen.Compared with the before,the cleaning rate,loss rate and screening efficiency have improved significantly.Finally,the Modal module of ANSYS Workbench was used to do modal analysis on the new cylindrical screen.The natural frequency range of the first to sixth modes was 157Hz-260Hz,which was within the safe frequency range.(4)This paper has made harvest test in accordance with the "YT 498-2013 Rice Combine Harvester Operation Quality" and "GBT 8097-2008 Harvester Combine Harvester Test Method." The experimental results show that the performance have greatly improved.The indicators are as follows:cutting height is 15.23cm,loss rate is 3.3%,crushing rate is 0.2%,stalk-cutting rate is 94%,no pollution and leakage.The impurity content is 7.4%,which greatly reduced before the improvement.