The article presents the results of a study of a high-performance grain cleaning machine for the preliminary cleaning of grain pile with a closed aspiration system. The fl ow regimes of the "air-grain pile" mixture determined by the Reynolds number and the bulk concentration of particles are established. As a result of the modeling, further directions for improving pneumatic systems of grain cleaning machines were determined: the cleaning effi ciency of the Е 0 fraction of pure grain from light impurities, shriveled and crushed grain reaches 82%, the output cleanliness of the grain was 93.7%, and the loss of full grain to waste P z = 0,017%. The average speed of the air fl ow in the separating channel is U = 7.12 m/s, its coeffi cient of variation across the width of the separating channel is v = 12,7%. The results of the experimental data confi rmed the adequacy of using mathematical modeling of the air fl ow in the pneumatic system of a grain cleaning machine to substantiate the basic parameters of the pneumatic system.
The article gives the results of the comparative tests of wear-resistance and reliability of metal-cutting tools equipped with carbides of ВК8, Т5К10 ,Т15К6, КНТ16 and ТН20 brand marks undergoing linear turning of test cylinders steel-faced with Np-30KhGSA wire. Intense hardness, structural imperfection and ridgeness of the metal coating make its further mechanical processing more difficult. Experimental technique is based on the cutting temperature persistence. Optimum cutting data for the cutting bits equipped with carbides of ВК8, Т5К10, Т15К6, КНТ16 and ТН20 brand marks have been found. Comparative tests proved that wearresistance of the instruments equipped with carbides Т5К10, Т15К6 and КНТ16 is 1,4-1,8 times higher than of those equipped with ВК8 carbide.
The purpose of this work is a mathematical description of sieve frame structural and technological parameters necessary for the implementation of the technological process model of a grain cleaning machine operation. The paper presents the results of the study of the grain cleaning machine sieve frame operation. A kinematic study of a flat swivel multi-link mechanism of the grain cleaning machine sieve frame was made. The method of determining the coordinates of the sieve frame nodal points was developed to calculate their speed. Structural and technological parameters of the mechanism were also studied.
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<p>This article presents the results of a study of the sieve mill of a grain cleaning machine with a drive based on a linear asynchronous motor instead of a classic mechanical drive. The purpose of this work is to describe the structural and technological parameters of a sieve mill with a linear asynchronous drive to implement a mathematical model of the technological process of a grain cleaning machine work. A kinematic study of the flat hinged mechanism of the sieve mill of a grain cleaning machine was carried out, for which all geometric dimensions are known and the laws of motion of the leading link - the electric drive of the sieve mill based on a linear asynchronous motor are determined. As a result, the following were determined: kinematic modes <italic>k</italic><sub><italic>P</italic></sub> > <italic>k</italic><sub><italic>B</italic></sub> > <italic>k</italic><sub><italic>H</italic></sub> of sieve mill vibrations under various technological conditions; laws of motion of all parts of the mechanism of the sieve mill, movement, speed (0.34... 0.36 m/s) and acceleration (5.8... 6.9 m/s<sup>2</sup>) of the driven links; a mathematical model of the kinematic scheme of a sieve mill of a grain cleaning machine with a drive from a linear induction motor has been developed. The use of a linear induction motor compared to existing (classical) drive designs as a drive of a sieve mill in a grain-cleaning machine significantly reduces the metal consumption of the structure (drive shafts, transmission mechanisms, connecting rods, bearings are excluded from the structure), and energy consumption is also reduced due to pulse drive operation; makes it possible in a wide range of technological parameters regulation for various crops, including various physical and mechanical parameters of the crop being cleaned.</p>
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For many years, the Kazan State Agrarian University has been engaged in research to find new highly effective technical solutions for processing seeds of various crops in the conditions of agricultural producers. One of these developments is a machine for removing the husk from the seed of the aeromechanical type. A distinctive feature of these machines is using in the design an additional working body, made in the form of a mesh confusor, located on the exhaust pipe of the fan-thrower. The aim of the work is mathematical modeling of the movement of achenes in the working areas of aeromechanical devices. The study uses the positions of gas dynamics and analytical geometry. The size and direction of the air flow in the working areas of the seed material are influenced by the geometric parameters of the main working bodies. According to the mathematical solutions, it can be seen that the components of the air flow velocity in the transverse and longitudinal directions change along the length of the confusor. And to determine the parameters of the movement of the achene in the working areas of machines for removing the husk from aeromechanical seeds, it is necessary to know the physical, mechanical and technological properties of seeds, the parameters of the air flow, as well as the structural and technological parameters of the surfaces of the main working bodies. The resulting mathematical models describe the movement of the seed air mixture in the working area, with a numerical solution on a computer you can get a graphical image of the trajectory of the movement of seeds in the confusor, which allows to build a nomogram for calculating the parameters of the confusor and segment, thus justifying the main design and technological parameters of the machine for removing the husk from the seed of the aeromechanical type.
The purpose of this study is to increase the efficiency of the technological process of a combine harvester cleaning system. It involved the simulation of the actual work process, the identification of problem areas and the uniform airflow distribution across the width of the sieve mill. The method for determining the class of ‘air-grain heap’ flow in the combine harvester cleaning system is presented in order to provide the mathematical description of its technical work process. As a result, the volumetric (Q = 8·10–6 ÷ 2.5·10–4) and mass (W = 0.01 ÷ 0.3) concentration of a grain heap in different sections of the sieve mill of the combine harvester cleaning system. The experimental measurements of the airflow speed on the sieve mill’s surface for the existing structures of the cleaning system in modern grain harvesters were 3.75 ÷ 10.2 m/s. The data obtained will be used in the future to implement a mathematical model for a complete description of the technological process of a combine harvester cleaning system using methods based on two-phase flow mechanics.
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