Design And Experimental Study On Crushing Device Of Corn Combine Harvester With Ear And Stem Harvesting

With the rapid development of the mechanized corn harvest technology and equipment level,and the implementation of the relevant policies and regulations banning the burning of straw,it has become an inevitable trend of mechanized corn harvest for the combined corn harvester to harvest corn ears and straw at one time.Aiming at the problems of high power consumption and low pickup rate of comminuting device in existing corn combine harvester,this paper designed the comminuting device and solved the problems of high power consumption by reducing the rotating speed.With straw crushing device speed and blade structure as the research object,the design and development of maize straw crushing device,and has carried on the field experiment,based on the maize straw bundle of straw crushing pressure square requirements,by optimizing the structural parameters of the blade and knife roller speed solve the problem of large low collecting rate and low power consumption,the main research contents and conclusions are as follows:(1)The three-dimensional solid design of the crushing device establishes the three-dimensional solid model of crushing roller,blade,shell and overall assembly.The crushing roller is composed of a cutter shaft,a cutter base and a blade.The design of the blade includes four types of optional blades.The shell is composed of two end plates and a curved mask plate.The design of the end plate and the curved mask plate takes into account the working requirements of the straw conveying parts after crushing and carries out the overall design.(2)Finite element analysis of the crushing device model.Solidworks Simulation was used to analyze the stress of the model established by four blade forms,and the distribution cloud charts of the equivalent stress,displacement and safety coefficient of the four models were obtained.The analysis results proved that the design of the blade met the requirements of stiffness,strength and safety conditions.Using ANSYS Workbench,the prestressed modal analysis of the grinding cutter shaft in the crushing device was carried out,and the natural frequency and modal mode shapes of the first 6 orders of the grinding cutter shaft system were obtained respectively.The results of modal analysis show that the designed speed of grinding cutter shaft is far lower than the lowest limit speed of the system,which meets the needs of practical work.(3)Production and field test of crushing device.According to the results of design and simulation,crushing device was made and assembled on three-row self-propelled corn combine.Single factor field test and test were conducted on four kinds of blades with three kinds of cutter shaft speed selected.The test results showed that the combined blade had the best effect.At a low rotation speed of 800r/min on the cutter shaft,the stubble height after operation was 6.7cm,and the picking loss rate was 2.082%.Moreover,there was no clogging in the crushing and conveying device,which met the operation requirements.