It is scientifically proven that the main factors affecting the productive potential of the animals, are the structure of fodder farms, the quality of feed and methods of feeding. It is known that concentrated fodder are an important component in the diet of animals and contribute to a stronger manifestation of their productive potential. For grinding grain into livestock is usually used crusher with different working bodies. The most widely is spread hammer mill grain crusher. This happens due to the simplicity of their construction and relatively high resource of working bodies. Currently, for farmers are of great interest the small-sized feed factories and units, which include crusher grain with a fan. However, along with the obvious advantages of hammer crusher, like with forced feeding of material and with pneumatic, have a number of disadvantages, one of which is the increased wear of their working bodies: hammers, screens, fan blades. The greatest interest from the point of reducing wear represent fan blades, as changing their shape, it is possible to reduce or increase the intensity of wear. In addition, they are more prone to wear, since all of the crushed material passes through them with great speed, while in the grinding chamber, the amount of grain distributed over a larger number of hammers, and the relative velocity of grains in it decreases. The analysis showed that the intensity of wear of working surfaces of the blades of the fan depends on the coefficient of friction of grains on the blade, the angle of the blade to the radius of the rotor disc, and the greatest influence on friction force has a peripheral speed of the blades. To increase the service life of the blades and reduce the intensity of wear and tear it should be choosen the correct form of the smallest possible radius of curvature. The method is proposed on the basis of which it is possible to calculate the amount of wear of fan blades, taking into account its aerodynamic characteristics.
Dual-flow hydromechanical transmissions are becoming increasingly widespread in the designs of modern land transport and traction machines (tractors, automobiles and high-speed crawler vehicles). This happens mainly due to the desire to increase the efficiency of transmission, although the capabilities of dual-flow hydromechanical transmissions are broader. In order to select a dual-flow hydromechanical transmission scheme in relation to specific operating conditions, it is necessary to know the advantages and disadvantages of various schemes, their potential capabilities. The evaluation of the operation of each circuit can be made on the basis of their kinematic and force analysis. The article deals with 12 dual-flow schemes of hydromechanical transmission with a differential element in inlet and outlet with a mixed meshing of gears, the results of the power analysis are shown. For the estimated parameters of a double-flow hydromechanical transmission were taken: й - power ratio of a double- гмп flow hydromechanical transmission; ан - coefficient of loading of the pump wheel of the torque converter; ам -load factor of the mechanical branch of the closed transmission contour; аa - load factor of the solar gear of the three-link differential mechanism. For each of the schemes considered, analytical dependencies of the estimated parameters on the internal parameters of the hydromechanical transmission were obtained. For the parameters were used the characteristic k of planetary gear set, power йгт and kinematic игт gear ratios of torque converter. It is assumed that, at the boundaries of the range й = да and й = 0. Calculations have been performed to determine the parameters й , гмп гмп гмп ан , ам u аа for different values of k and й , results of which made possible to evaluate the potential transforming properties of the schemes of two-flow hydromechanical transmissions independently of the model of the used hydrotransformer.
Perspective structures of machine and tractor units for combination of technological operations when performing of the field mechanized works are offered. Combination is based on the operations coinciding on agrotechnical terms of the performed works: introduction of mineral fertilizers - stubble processing of the soil; hulling of an eddish - application of fertilizers; chisel plowing soils - introduction of mineral fer-tilizers; crops of intermediate cultures - processing of the soil and etc. Efficiency of combination is determined by higher quality of the performed works without gap by time, moisture economy, elimination of the losses brought in the soil of materials (seeds, fertilizers, pesticides), respect for threading and rhythm of production processes, decrease in need for the equipment and a labor power and all cost types (labor, cash, energy). All this promotes increase in competitiveness of the made products. Completion of the offered new structures of multipurpose aggregates is based on use of the serial basic machines checked in production (deep-rippers, plows, cultivators, disk tools, seeders, etc.) equipped with various devices for introduction of mineral fertilizers, seeds, their seal which are also checked in or-dinary operation to the soil on the optimum depth and a compacting of crops. Except economic effect of combination of transactions by the provided aggregates are obvious agro-nomical and cost efficiency: decrease in consolidation and a puddled condition of the soil that influences its fertility, complete use of soil moisture that guarantees amicable shoots and future harvest.
The purpose of the paper is to perform a comparative analysis of the strength properties of impellers made of a composite material with strength properties of impellers made of aluminum alloy. The main method of this study is the finite element method. Pre-and post-processor Femap was used to prepare the model and process the research results. The calculations were performed using a linear solver NX Nastran. Calculations are carried out for two wheel sizes (two diameters) and two calculated cases (for maximum working angular velocity and for destructive velocity). During research stress-deformed states of impellers were obtained. Stress distribution is qualitatively identical in all design options. Redistribution of stresses in impellers due to different materials stiffness is absent. Strength factor as a result of replacement of materials for the 1st and 2nd sizes fell by 7.8 and 5 %, respectively (absolute values - 1.06 and 1.16 respectively). Stress-deformed states obtained during strength calculation can be used for the subsequent manufacture of an impeller made of an anisotropic material. The calculation of frequencies and forms of free oscillations showed a decrease in the frequencies of free vibrations of impellers made of composite material, but it should be noted that even the «lowest» frequencies have approximately twice the maximum frequencies of the working range of the turbocharger. The results of the analysis show the promise of replacing materials in order to improve reliability. Strength calculation showed the need for additional experimental studies of impellers made of composite materials.