Vol 35, No 1 (2025)

Introduction. The need to increase productivity of grain harvesting equipment and minimize crop losses has given rise to the increasing use of axial-flow combines (rotary harvester). The efficiency of harvesting operations depends on correct setting of the adjustable harvester parameters allowing full use of its design capabilities. For this reason, it is relevant to study the problems of optimal adjusting the working tools of a harvester operating in various environmental conditions.
Aim of the Study. The study was aimed at developing an approach to the choice of optimal values for the adjustable parameters of the rotor type grain harvesters.
Materials and Methods. Harvesting quality indices, adjustable parameters, and environmental factors are interdependent, so there has been used a linguistic approach to the description of the subject domain. Information about environmental conditions, the harvester technical state, interrelations between parameters and harvesting indicators is fuzzy that has led to the application of the theory of fuzzy sets to solve the problem of optimal choice of the adjustable parameters. The procedure of fuzzy logic inference has been performed in Fuzzy Logic Toolbox (MatLab) package.
Results. There are presented the results of the developed approach to the problem of operational presetting adjustable parameters of a rotary harvester when harvesting various grain crops under different environmental conditions. The problem solution concept has been developed on the basis of the fuzzy logic formalism. A linguistic description of the problem has been given. Models of the considered features in the form of membership functions are proposed, which adequately take into account the external conditions in which the harvester operates. Basic and extended term sets have been identified. The optimal models have been selected on the basis of the consistency analysis of fuzzy expert knowledge using the indicators of general and pair consistency of the models. The results of the solutions obtained have been illustrated. On the basis of collected and analyzed expert information there has been created a base of fuzzy expert knowledge including the fuzzy production rules for 12 adjustable parameters of TORUM harvester. Different combinations of the values of environmental factors have been considered, for which there has been given an inference about specific values of the adjustable parameters.

Discussion and Conclusion. The practical significance of the research carried out lies in
the creation of a basis for an intelligent information system to help a rotary harvester
operator in making decisions on choosing adjustable parameter values when harvesting
various grain crops. The use of such a system in field conditions in combination with sensors for continuous monitoring of harvesting conditions and an automated image analysis system will allow for a prompt response to changing conditions, significantly increase work efficiency and reduce decision-making time. The implementation of such systems will significantly reduce the information load on the operator, as well as use operators with little practical experience during harvesting. The development of such information systems creates the preconditions for increasing the level of automation of intelligent control of a grain harvester and is an important stage in the implementation of the approach to unmanned control of a harvester.

Introduction. With the standard mode, heat transfer in one-pipe heating systems is significantly inferior to heat transfer in two-pipe systems. The development of pulse technologies for heating systems made it possible to create a reversible heat transfer in which heat transfer in heating devices is improved through the heat transfer agent pulsation, but the heat transfer coefficient depends largely on technological solutions for creating this reversing mode. In this connection, developing original technological scheme for reversible heat transfer based on the diaphragm pump and substantiating optimal frequency range of its operation is relevant and practically important for improving one-pipe heating systems.
Aim of the Study. The study is aimed at increasing the efficiency of one-pipe heating systems through creating reversible heat transfer agent supply using a diaphragm pump.
Materials and Methods. There were used the methods of circuits, physical experiment and mathematical statistics to establish experimental dependences of the temperature difference for the heating and heated circuits of reversible heat transfer through one pipe on the frequency of pulsations of the heat transfer agent flow at different inlet temperatures in dynamics. The physical experiment was carried out at two heat transfer agent temperatures
(50 and 60°C).
Results. With the use of the laboratory setup for reversible heat transfer through one pipe, there have been found the optimal frequency for two heat transfer agent temperatures, providing an increase in the temperature difference in the circuits and the heat transfer coefficient. There have been found dependences of temperature difference for heating (external) and heated (internal) circuits of heat transfer and heat transfer coefficient for the heat exchanger on the pump diaphragm stroking rate.
Discussion and Conclusion. As a result of the physical experiment, it has been found that the heat energy transfer through one pipe is possible in a wide frequency range (from 0.15 to 0.4 Hz), while the greatest heat transfer is recorded at a frequency of 0.3–0.4 Hz. The technology of heat transfer through one pipe can be successfully used for heating common areas in apartment buildings, dormitories, industrial and agricultural facilities, and individual residential buildings.

Introduction. The main problem of the grain hammer mill is over-grinding of grain caused by untimely removal of the final product from the grinding chamber. A way to effect the air flow arrangement in the grain hammer mill is to change the air pressure around the grinding chamber. Therefore, the study of the effect of air pressure around the grain hammer mill on the quality and energy indicators of its operation is an urgent task today.
Aim of the Study. The study is aimed at determining the effect of air pressure around the grinding chamber on the air flow motion pattern in the grain hammer mill and its energy indicators.
Materials and Methods. For a theoretical study of the air flow circulation in the grinding chamber, there was constructed a geometric model of the rotor placed in the grinding chamber. The Reynolds averaged equations of a continuous medium motion was the basis for the mathematical model of air motion. The calculation results were used to construct the velocity fields for the air flow. To conduct experimental studies, there was designed a pressure chamber that allows changing the air pressure in the grain hammer mill.
Results. Based on the results of theoretical studies, it has been determined that the pressure decrease in the grinding chamber by 10 times reduces the power consumption by 112 watts. Experimental studies have shown that when the pressure in the grinding chamber decreases, the power consumed by the engine for all types of rotors decreases too. Also, an increase in air pressure in the grinding chamber leads to a change in the amount of grinded grain remains on the sieve to 0 mm: for the blade and hammer rotors, the amount of remains decreases, and for the hammer-blade rotor it increases.
Discussion and Conclusions. The results of theoretical and experimental studies have shown that decreasing the air pressure around the grinding chamber can decrease the energy costs for the technological process and air flow motion inside the grinding chamber, and reduce the over-grinding of grain. The study results make it possible to design the grinding chambers for grain hammer mills taking into account the air flow motion.

Introduction. An important area of agricultural industry development is improving the operating efficiency of wheeled mobile agricultural machinery. The real situation analyzing has shown the presence of a number of difficulties associated with many factors including high agricultural machine weight, which, along with increased performance, leads to the over-compaction of all soil layers that results in reduced yields of cultivated crops and increased energy consumption during subsequent processing. Despite the significant successes of domestic and foreign researchers and research teams in this area, these difficulties impede the development of an optimal solution to the problem. Therefore, the relevance of the materials presented in the work is beyond doubt.
Aim of the Study. The study is aimed at assessing of agro cross-country ability of the fifthgeneration domestic combine harvesters when harvesting winter wheat.
Materials and Methods. In the study of the agro cross-country ability of combine harvesters, there was applied an experimental method using the measuring complex “tire tester” and other control and measuring devices. As the test objects there were used the propelling devices of the combines on the tires of the models F-136, F-179, F-81E, F-81DP and by the company “Cood year” of the same standard size 30.5-32.
Results. There were determined the indicators of agro cross-country ability of fifth-generation combine harvesters with the wheel propelling devices equipped with the tires of different models. Using standard methods for determining the maximum pressures on soil and normal stress at a depth of 50 cm, it has been found that these combines do not meet the requirements of GOST R 58655-2019 at any options of completion of driving wheels with tires (except for the installation of experimental tires when soil moisture is not more than 0.5 NV). Direct measurement of the indicators of agro cross-country ability of combine harvesters has shown that judging by the figures of the maximum pressures when driving wheels are in contact with soil and stress caused at a depth of 0.5 m, the fifth generation combine harvester in harvesting spike cereals in the conditions of the Southern Federal District meets the requirements of GOST R 58655-2019 on all compared tire.
Discussion and Conclusion. Identifying agro cross-country ability indicators through direct measuring has shown that it is possible to use modern domestic combine harvesters equipped with radial tires (with optimal reinforcement of the inner structure) and experimental diagonal-parallel tires for harvesting spike cereals. The results of the study should be taken into account when equipping of the fifth generation combine harvesters with tires.

Introduction. The task of high-quality cleaning of root crops from soil is relevant at all stages of preparing roots for further processing, feeding to animals, and selling. In the machines for cleaning root crops from soil, there is mostly used water. With the water consumption for washing a unit of mass of soiled root crops up to 200–400%, the use of water creates a huge problem including soiled water treatment. The dry method of cleaning root crops is most common in practice and involves the use of appropriate machines, which are not always able to provide the required quality of the finished product. Therefore, the problem of developing a root crop cleaner by the dry cleaning method and substantiating the cleaner optimal parameters to ensure the required quality of the finished product is important and relevant.
Aim of the Study. The study is aimed at substantiating theoretically the parameters of a root cleaner with adjacent rollers rotating at different frequen cies.
Materials and Methods. The subject of the study is the technological process of cleaning root crops with the dry method. To realize this process, there has been developed a cleaner of root crops from soil, the key features of which are the use of a roller transport-cleaning working element and the ability of adjacent rollers rotate at different frequencies. Individual design parameters of the proposed cleaner have been substantiated theoretically.
Results. There have been determined the forces acting on the root crop when it is located on rotating rollers. There has been found the dependence of the angular displacement φ(t), angular velocity ω(t) of the root crop located on rotating rollers, and the dependence of the coefficient of root crop sliding friction on the rollers on the angle α, which determines the relationship between the main design parameters of the working element, in particular, the diameter of the rollers and the distance between them, and the physical and mechanical properties of the root cr ops.
Discussion and Conclusion. The studies of the root crop cleaner conducted in laboratory conditions have confirmed the results of theoretical studies and showed that with a length of the transport-cleaning working element of 2 m within a time of 34,4 s it is possible to achieve an efficient cleaning of 78% when the cleaner is equipped with 16 rollers and the ratio of the rotation frequencies for odd and even rollers is 220/250 min^–1. The study results are useful for creating and modernizing technical means for post-harvest processing of root crops, conducting further studies on technological improvement of similar means of mechanization of agricultural processes, and for using in the educational process to train technical special ists.

Introduction. The resistance of soil cultivation equipment components to abrasive wear is an important operational characteristic. Employing various methods to harden the surfaces of these components is an important task for agricultural machinery manufacturing. This article focuses on studying the effectiveness of using epoxy-gravel composites to harden composite ploughshares operating under conditions causing increased abrasive wear.
Aim of the Study. The study is aimed at substantiating the practical application of epoxygravel composites to harden composite ploughshares with the ability to restore the components having radial wear.
Materials and Methods. Within the framework of the study on restoring worn ploughshares of the reversible plough produced by “Kverneland Group” company and aggregated with the tractor “Kirovets K-744”, there were used coatings based on epoxy composite with gravel crumbs of different fractions, in which the ratio of epoxy compound to gravel filler was 50:50. During the machine-tractor unit operation, there was monitored the wear dynamics of the restored ploughshares. The ploughshares under study differed among themselves by the fraction of gravel crumbs in the epoxy composite. For each ploughshare under study, there were plotted the dependence of wear dynamics on operating time.
Results. The use of gravel chips with a dispersion of gravel particles of 1.75 mm in epoxy resin has shown the best resistance to abrasive wear. The optimal operational characteristics of the composite derive from the high adhesion of the particles to the epoxy base that prevents their delamination and provides the stability of the coating under mechanical and shock loads. This proves the effectiveness of using epoxy-gravel composites to harden the working surfaces of ploughshares that in the conditions of abrasive wear reduce the probability of radial wear.
Discussion and Conclusion. The conducted studies confirm that the use of epoxy-gravel composites makes it possible to increase the wear resistance of coatings by 2.8 times compared with factory-made parts. This allows increasing the service life of ploughshares operating under conditions of intense abrasive friction. The use of epoxy-gravel composites to harden ploughshares is important for agricultural enterprises, because of the high resource of hardened surfaces during their operation.