DETERMINATION OF OPERATION MODE PARAMETERS OF A CUTTING UNIT OF THE DEVICE FOR POTATO DECAPITATION

The technological method of decapitation (the removal of apical shoots) helps to increase the potato yield. For carrying out decapitation a mechanised device has been designed. Agrotechnical requirements for decaptivation include a high-quality cut of apical shoots without looseness, as this injury contributes to the introduction of various, especially viral, pathogens. To prevent diseases, the cut place is treated with a disinfectant solution. An important element of the device is the cutting mechanism. The authors suggest a design algorithm of a rotary cutting device able to make free cuts. It has been determined that with an increase in the number of cutting blades, the intensity of changes in the size of the outer diameter of the rotor decreases. With an increase in the number of cutting edges from one to two, the outer diameter of the knife will decrease by 21.3%, from two to three – by 9%, from three to four – by 5%. The total length of the cutting edges of the rotor depends on its minimum radius, cutting speed and the machine speed. The authors have calculated the external diameter of the knives at different rotor speeds and the values of its internal diameter depending on the number of cutting edges. The calculated speed of the unit has amounted to 2 m/s. The authors have found that to ensure quality and reliable cutoff of potato shoots when carrying out decapitation, one should use a cutting rotor with three blades rotating with a frequency of 1200 min-1, with the outer diameter of the cutting edges not less than 0.35 m, and the working height of the blade of 0.04 m.