DETERMINATION OF THE MAIN PARAMETERS OF THE ROTARY MOWER CUTTING APPARATUS

Abstract

For mowing grass during harvesting of hay or haylage, support-free mowers with rotary movement of knives are used mainly, the productivity of which is much greater than segment-finger mowers. Free-cutting cutting apparatuses with rotational movement of knives happen with their rotation around the vertical (rotary) and horizontal (rotary) axes. Mowers that are equipped with rotary cutting devices significantly grind grass, so they are used in mower-grinders and lawn mowers. The purpose of the work is to substantiate the methodology for calculating the structural and kinematic parameters of rotary cutting devices, corresponding to the conditions of their use. The main parameters characterizing the operation of rotary cutting devices are: area, mows than in one revolution of the disk; knife working length; overlapping knives of adjacent rotors; cutting speed. In determining the basic parameters of the rotary cutting apparatus of the mower, the following assumptions were made. It was believed that the angular speed of the rotor and the translational speed of the mower are unchanged, and the movement of the unit is straightforward. In addition, the cutting apparatus performs mowing in a plane parallel to the soil surface, that is, in a plane perpendicular to most plant stems. It is shown that the absolute speed of any point of the knife varies from the maximum value equal to the sum of the peripheral speed of this point and the aggregation speed of the mower, to the minimum - the difference of the above speeds. It was found that the working length of the cutting edge of the knife is directly proportional to the speed of aggregation of the mower and inversely proportional to the angular velocity of the rotor and the number of knives mounted on it. The overlap of the path of the knives of adjacent rotors depends on the radius of the rotor; the number of knives mounted on it and the kinematic mode of operation of the cutting apparatus. Moreover, an increase in the radius of the rotor requires an increase in overlap, and an increase in the kinematic mode and the number of knives leads to a decrease in the overlap between the paths of the knives. The resulting dependence, which allows you to determine the area, mows than in one revolution of the rotor.