Driving System And Frame Optimization Design Of Cutting Longitudinal Flow Threshing Cleaning Device

In recent years,with the increase in the utilization rate of the cut longitudinal flow combine harvester,higher requirements have been put on the work performance and work efficiency of the threshing cleaning device for its core components.The design of the drive system of the cut and longitudinal flow threshing and cleaning device of the existing products is unreasonable,the layout of the threshing and separation drive system is relatively complex,the rotation speed of the threshing roller is fixed,and the adaptability to crops is poor.The overall structure of the threshing and cleaning rack is not compact,the stress distribution of the rack is uneven,and there is a situation of strength redundancy in the rack.By optimizing the threshing and cleaning drive system and the lightweight design of the frame,the reliability of power transmission of the threshing and cleaning device can be improved,and the stability and patency of the whole longitudinal-flow combined-harvester machine operation can also be improved.The paper takes the Taihu Lake TH988 cutting longitudinal flow full feed combine harvester as the research object,combines theory,simulation analysis and experiment to optimize the transmission system and frame of the threshing cleaning device.The main tasks are:(1)Summarize the problems existing in the transmission system of the existing threshing and full-flow feeding combine harvester cleaning system,and set up a new transmission scheme according to the working flow,working relationship,and transmission system design principles of the working components of the cutting longitudinal flow threshing cleaning device.The results of the field trial on the longitudinal flow combined harvester threshing cleaning device were designed in the analysis group to design the working parameters of the transmission components and verify the key parameters.Between the cutting longitudinal rollers,a two-speed reversing transmission box device is designed to solve the drawback that the rotational speed of the threshing roller is not adjustable.(2)The reliability of the threshing cleaning drive system requires the strength of the rack to support it.Taking the Taihu Lake TH988 cutting longitudinal flow full-feeding combine harvester as the research object,the three-dimensional model of the threshing cleaning rack was plotted using SolidWorks software,and the rack wasobtained according to the stress distribution values of the transmission components mass distribution and the operating parameters of the rotating components.Stress distribution.Based on the material strength theory,using ANSYS workbench software static modules to simulate the analysis of the rack,the rack strength redundancy distribution is obtained.Optimize the structural topology of the rack with the weight reduction goal of 15%.According to the topology optimization results of the structure,consider the design requirements of the installation requirements of the transmission components,the load distribution of the rack,and the manufacturing process,etc.,and perform the structure and structure of the threshing cleaning rack.The optimal design of the shape.(3)In addition to meeting the design requirements in terms of weight and strength distribution,the threshing cleaning rack also contributes to the stability of the drive system.The ANSYS workbench software was used to perform modal analysis on the optimized threshing cleaning rack to obtain the low-order modal parameters of the rack.Analyze the natural frequency and mode shape of the low-order modes to provide reference for the optimal design of the frame structure.At the same time,compare the modal parameters with the excitation frequency generated by other working components on the combine harvester to check whether the rack will Resonance occurs.Through the experimental modal test system,the modal parameters of the optimized threshing cleaning rack are analyzed,and the results obtained from the two modal analysis methods are compared and analyzed from the two aspects of the natural frequency and the vibration mode to verify the finite element mode.The accuracy of the analysis results and the feasibility of finite element modal analysis methods.(4)The test components of the optimized threshing cleaning device's transmission components were tested.The test results showed that the threshing cleaning device operated smoothly under both no-load and full-load operating conditions,and the transmission component working parameters met the design requirements.The standard of harvesting operation was achieved;quality comparison tests were performed on the threshing and cleaning racks before and after optimization.The test results showed that the weight of the optimized rack was 5.7%,and the weight of the rack was more obvious.