DYNAMIC CHARACTERISTICS OF SUNFLOWER STEMS
The article is focused on the technical solution of the problem of reduction of sunflower achenes loss in the process of its harvesting by the grain combine. It is substantiated that increase of sunflower achenes losses is the result of striking impact of the working bodies of the reaper reel. The layout of the reaper machine operation, which is equipped with a screw-reel for sunflower harvesting purposed to reduce the acceleration of the sunflower stem movement, and accordingly, the loss of achenes has been analyzed. The sunflower stem scheme, which shows its geometric and dynamic characteristics used in the mathematical derivation of expressions for determining the moments of stem portions inertia is suggested and the dimensions of the geometric portions are denoted. Using the Steiner theorem, there were determined the moments of the portions inertia with regard to portions of the axes of the system of x0, y0, z0 coordinates. The equations of circumference of sunflower head base and the arc of its sphere are described. As result of mathematical transformations there were obtained the total moments of sunflower stem inertia.