The Experiment Research On Parameters Of Nails Teeth Of The Axial Flow Threshing And Separating Device

Paddy is one of the main grains in china. it plays an extremely significant role in grain producing. To speed up the development of the mechanization of paddy producing, improve comprehensive production capacity of paddy, is an important measure to ensure grain safety of china, which also has great meaning to promote modernized agriculture. Axial flow threshing device is used more and more widely in practical producing, for which has favourable function, wide adaptability, gentle threshing and adequate separating, therefore the deep researching to axial flow threshing device seems very necessary. This article which is on the bases of summarizing and analyzing the existing state of domestic and foreign research to gather paddy by axial flowing, through the method which combining theory analysis with experimental study, research and explore on the function and parameters of the nails teeth of axial flow threshing and separating device deeply. Drawing conclusions as follows:1.The test study of single factor on nails teeth distance has show that: When the nails teeth distance changed ,The Extractives along the axial and circumferential distribution is similar. The change of nails teeth distance has great effect on power consumption, unthreshed loss rate, total loss rate and straw broken degree. It also has effect on broken ear rate, rubbish rate and brown rice rate in some degree, but it isn't very obvious. When other parameters are certain and the nails teeth is 16cm, the power consumption, rubbish rate, broken ear rate,brown rice rate, straw broken degree, mixed loss rate, unthreshed loss rate, total loss rate and other performance indicators of device are descend equally.2.On the base of the test result of single factor, select crop feed rate, rotor speed and concave clearance, three factors, the regression model about the performance index and factors are obtained by quadratic orthogonal rotary experimental designing many factors being in progress, and analysed the influence regularity of different factors on power consumption, broken ear rate, rubbish rate and total loss rate; Obtain the principal factors which influence performance indicators; Adopt main objective function, according to equation of regression of different performance index and optimize the result by MATLAB, and comprehensively conclude the optimize parameters: crop feed rate is 2kg/s, rotor speed is 600r/min, concave clearance is 30mm, through checking test,the performancewe gain meet the technique request very much.3.We photographed the progress of grain threshing and separating in the threshing and separating space on line by the high-speed photography, researching and analyzing motion trace of paddy threshing progress of broken ear, colliding progress of kernels, motion trace of short straw and dropping trace of the mixture distribution by image returning. Some conclusions were drawn as follows: the paddy come into the threshing and separating space, the kernels of paddy are separated from the branch with nails teeth impacting by the threshing parts, stripping and rubbing between the rotor and concave. Most kernels which are threshed overcome the obstruction of the thin layer and break through the thin layer to reach concave surface where they come into being separated by gravity and centrifugal force. Motion trace of most free kernels is a straight-line, move horn with axial direction of rotor in the threshing space. The motion trace of broken ear is parabola in threshing space. Its motion progress doesn't move in parallel but move and surge ahead continuously in threshing space. The motion trace of short straw is curve for its light mass, and the change of the moving speed is by a bigger margin. Free kernels easily are collided by the threshing parts, straws, etc. The motion trace and motion direction will change after colliding. When mixture exhausted from concave, its motion trace is curve which is down acceleration.The motion trace of kernels is regularity, motion trace of most kernels is parabola, while, motion trace of residues is irregular curve and the motion is unstable, fluctuation rang of velocity is bigger.