The Study Of Drag Reduction Performance Of Narrow Tooth Soil Working Parts With Its Geometric Characteristics

The soil working parts, as the direct carrier of engineering machinery and agricultural machinery which interacing with the soil, consume a lot of energy in the processing process. Reducing working resistance of soil working parts, has important significance to improve the mechanical efficiency, energy saving and emission reduction. Our research group discovered that soil animal’s claw contour curve has the variable curvature geometry contour curve, which is its key to have drag desorption ability. Therefore, finding the relation between directrix of the soil working parts and working resistance has an enlightening significance to find the best alignment with the drag reduction performance and design the resistance reduction and energy conservation soil parts.Analyzed and summarized the typical directrix of the bulldozing plate, shovel, bucket and other construction machinery, disk plow, plow, and other agricultural machinery, we get straight line, arc, parabola, bionic, cycloid curve. From the angle of curvature geometry(curvature radius curvature trend line, comb and trajectory curvature center), we analysis the intrinsic properties of these typical alignments. According to the current research results of all relevant researchers, we infer that the diretrix which has the curvature of the trend line has many fluctuations, and fluctuations in value approaching to zero curve, the radius of curvature center has tended to the same point and distributed on both sides of the original curve, be used to the soil working parts have better drag reduction performance. Executed the explicit dynamic analysis, we obtained the working resistence and soil disturbance under different cutting speeds. We designed and machined the vatiable curvature subsoiler according to the parts which has the minimum working resistance in the finite element analysis. In contrast, we processed the " mechanical standard " subsoiler. Through tested the field work resistance, we found, compared to the " mechanical tandard" subsoiler, the variable curvature subsoiler reduced working resistance to 6.24 percents in 4km/h, 21.63 percents in 8km/h, 13.64 percents on all speed range. we validated the conclution that the soil working parts with the variable curvature alignment have better drag reduction effect in theory analysis and simulation anlysis. To further, it vertifies that by the geometrical characteristic of the curvature of the directrix, we can judge the working resistance of the contact surface. This is the first study to try to find the optimal alignment curvature of drag reduction of soil working parts from the angle of geometric characteristics, which opens a new direction for the study of resistance reduction and energy saving in soil working parts.