A THEORETICAL STUDY OF THE PROCESS OF TRIMMING BEET TOPS USING PASSIVE BLADES

Based on the principle that the potential energy of the system is equal to the external work expended during the trimming of sugar beet roots with a passive flat knife, the study substantiates the possibility of reducing the load on the working body by rationally selecting the knife installation angle relative to the axis of motion of the top-trimming unit. It has been established that changing this angle directly affects the cutting force and the length of the knife travel path in the root crown zone. Therefore, a properly selected blade angle makes it possible not only to reduce the force acting on the knife, but also to improve the quality of top removal by increasing the cutting path and ensuring more stable interaction between the blade and the root surface. Before performing the technological process of sugar beet top trimming, it is advisable to analyze the geometric parameters of the roots, primarily the average crown diameter, since this parameter determines the initial conditions for calculating the cutting force. By setting the blade thickness of the trimming device and using the established analytical dependence, the required force applied to the blade can be determined. Taking into account the strength limit of the blade material, the recommended operating speed of the unit is then calculated. At the same time, speeds that may cause resonance phenomena in the trimming device must be excluded from the acceptable range. Knowing the cutting force and the knife angle, the natural frequency of the device is determined using the proposed relationship. Further analysis of the obtained results makes it possible to identify the travel speeds at which resonance may occur. These speeds should be avoided during operation, as they can increase dynamic loads, reduce trimming quality, and accelerate wear of the working body. Thus, the proposed approach provides a consistent procedure for selecting the geometric and kinematic parameters of a passive flat knife, ensuring lower cutting resistance, improved top-trimming quality, and more reliable operation of the sugar beet harvesting unit.