Конструювання, виробництво та експлуатація сільськогосподарських машин. Загальнодержавний міжвідомчий науково-технічний збірник.
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Ідентифікатор медіа: R30-03925 (рішення Національної ради України від 25.04.2024 р. № 1418).
Мови видання: українська, російська, англійська, періодичність - один раз на рік.
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Item type:Item, Износостойкость сопряжений с зазором, восстановленных полиамидоэпоксидными пористыми покрытиями(ЦНТУ, 2020) Цапу, В. И.; Горобец, В. Ф.; Цапу, В. І.; Горобець, В. Ф.; Tapu, V.; Gorobet, V.В статье представлены результаты исследования износостойкости сопряжений с зазором, восстановленных путем нанесения пористого полимерного композиционного материала на одну из составляющих пару трения деталь. Установлено, что полученные нами пористые полимерные композиционные покрытия позволяют уменьшить износ по сравнению с композиционными покрытия без пор в 1,64 раза. У статті представлені результати дослідження зносостійкості спряжень з зазором, відновлених шляхом нанесення пористого полімерного композиційного матеріалу на одну із деталей, що складають пару тертя. Встановлено, що отримані нами пористі полімерні композиційні покриття дозволяють зменшити знос в порівнянні з композиційними покриття без пустот в 1,64 рази. The using of polymeric materials as coatings for the restoration of worn–out machine parts has found application in the industry of repairment. Their wider use is hampered because of poor adhesion strength, shrinkage, ageing, low wetting ability and other properties of polymeric materials. To improve the physical and mechanical properties of polyamide P12, it is advisable to add to the composition of various substances that help to reduce shrinkage, ageing, increase wear resistance. It is proposed to increase the oil absorption of the surface layers of polymer composite coatings by introducing 5...10% of sodium chloride (NaCl) into the composition. The obtained porous coatings were further subjected to wear tests under various lubrication conditions. The wear rate of the composite material under different lubrication conditions is different, so after 240 hours of testing, friction wear without lubrication was 18.8 ±2 μm, when using water – 16.8 ±2 μm, and when using LITOL 24 grease – 10±1 μm ... When using LITOL 24, a positive gradient of interfacial resistance of molecular bonds and surface layers is provided. Abrasion of the latter, as a rule, is not abrasive, but frictional and manifests itself in the separation of different, configurations of particles from the surface layer. Also, the lubricant is in the friction zone for longer because it is retained in the artificially formed pores of the surface layer of the coating. The presence of grease in the friction zone reduces the wear rate of the metal counter body. In those cases when there was no lubrication or there was water, the wear rate of the metal counter body was higher and practically had the same character. So, after 240 hours of testing, the following results were obtained: with friction and without lubrication In.l.=14 ±1 µm; friction in the presence of running water Iwater=13±1 µm; friction when using Litol 24, I=9±1 μm. Based on the results obtained, it can be stated that for a metal–porous polymer composite sliding friction pair, the types of lubricants affect the intensity of their wear. It should be noted that during the first hundred hours of testing, the evolution of the wear of the friction pair with different types of lubricant is practically the same and has a tendency to increase smoothly. This type of wear can be explained by the transfer of the composite material to the metal counter body. After removing this layer from the metal counter body, the process of its wear is different and depends on the type of lubricant. Metal counter bodies practically do not change the nature of wear when using water as a lubricant, as well as when friction without lubrication, but when using LITOL 24 lubricant, the wear rate is much less. The durability of friction pairs largely depends on the size of the gap. Thus, for the friction pairs studied with friction without lubrication, the linear intensity of the change in the gap value for 240 hours of testing will be 6.03 ∙ 10–8, for the condition of friction in running water and with Litol 24 lubricant, respectively 5.5 ∙ 10–8 and 3.6 · 10–8. In other words, we can say that in the studied area of 240 hours, the gap in friction pairs with friction without lubrication increased by 60 μm per 1 km of the distance travelled, when using water at 55 μm/km and 36 μm/km when using Litol 24 lubricant. It was found that the intensity of the increase in the gap in the friction pair when using a porous polymer coating based on a polyamide epoxy composition as a counter body in a metal–polymer friction pair, under lubrication conditions with Litol, is 1.64 times less than when using such coatings without pores. The obtained porous coatings showed higher wear resistance when using water as a lubricant (1.1 times less than that of the base one). The results obtained confirm that the creation of a porous surface layer in the coating of the polymer composition will contribute to an increase in the service life of the recovered friction pairs by replacing the usual metal–metal pair with a metal–polymer one.Item type:Item, Восстановление подшипниковых узлов скольжения полиамидоэпоксидными композиционными материалами(ЦНТУ, 2019) Малай, Л. Г.; Горобец, В. Ф.; Попескул, А. Т.; Malai, L.; Gorobet, V.; Popescul, A.Целью работы явлляется изучение трибологического поведения полиамидоэпоксидных композиционных материалов (ПЭКМ), в зависимости от концентрации отдельных компонентов. В качестве объекта исследования были выбраны трибологические пары металл–ПЭКМ, наполненные стеклянными микросферами и другими материалами. Мета роботи полягає у вивченні трибологічної поведінки поліамідоепоксидних композиційних матеріалів (ПЕКМ), в залежності від концентрації окремих компонентів. В якості об’єкта досліджень були обрані трибологічні пари метал–ПЕКМ, які наповнені скляними мікросферами та іншими матеріалами. The reliability, productivity and competitiveness of agricultural machinery, as well as related industries, is largely determined by the resource of sliding bearing units, which during operation are influenced by many adverse factors such as: high dust content, bad weather, temperature fluctuations, high humidity, aggressive medium, uneven loads, mechanical shocks, vibrations and shock loads, insufficient lubrication, etc. Therefore, the development and implementation of new materials for the restoration of sliding bearing units capable of working in such conditions is quite relevant and is of interest to science and practice in the field of technical service of agricultural machinery. Tribological tests were carried out on a universal tribometer UMT–2 using a special module for the pin–disk friction pairs. Visualization and recording of research results were carried out using a special program. The deviation of the location of the corresponding surfaces does not exceed 25% of the size tolerance of the corresponding surfaces. The studies were carried out under the following conditions: pressure 1 MPa, sliding speed 1,5 m/s, radius from the centre of the disk to the axis of sample 40 mm, Litol 24 was used as a lubricant. The proposed composite material as a matrix contains PA–12 polyamide (OST 6–05–425) – 70% and the epoxy oligomer P–EP.534 (TU 6–10–189–83) – 30%, and as fillers: molybdenum disulfide DM–1 (TU 48–19–133–90), hollow glass microspheres MS–VP gr. 5–4% and basalt fibre. The composite material was applied by hot pressing to one of the ends of the pins made of ordinary carbon steel without heat treatment. Studies on optimizing the composition of PECM were carried out using mathematical planning of experiments, namely, a 3–factor non–compositional plan of the Box–Benkin type. The obtained data were processed using the STATGRAPHICS program. An analysis of the equation shows that all factors contribute to a decrease in the coefficient of friction of the polyamide epoxy composition with steel (b1, b2 and b3, have negative values). Molybdenum disulfide, then glass microspheres and, finally, basalt microfiber (|b1|>|b2|>|b3|) most affects the coefficient of friction. The value of the optimal coefficient of friction (K=0,115). The values of these factors in coded coordinates are 5% – molybdenum disulfide, 23% – hollow glass microspheres and 4,31% – basalt microfiber from the composition. Based on the results of the studies, the following conclusions can be drawn: tribological monitoring of laboratory samples from composite polyamide–epoxy materials tested on carbon steel disks using LITOL lubricant showed a beneficial effect of all components of the composition on the friction coefficient; The results obtained made it possible to determine the optimal composition of PECM, at which the lowest coefficient of friction was achieved (K=0,115).Item type:Item, Опыт использования альтернативного топлива в автомобилях и его воздействие на окружающую среду(ЦНТУ, 2019) Бешлягэ, И. И.; Малай, Л. Г.; Горобец, В. Ф.; Бешляге, І. І.; Bershliage, I.; Malai, L.; Gorobet, V.В работе представлено описание результатов экспериментальных исследований экологических характеристик двигателя с воспламенением от сжатия, работающего на альтернативных видах топлива (дизельное топливо, биодизельное топливо в смеси с дизельным топливом, чистое биодизельное топливо и чистое рапсовое масло). Приведены результаты определения выделения дыма при работе двигателя с различными видами топлива, выброса CO2, СО и СН в выхлопных газах в зависимости от мощности двигателя. Изложены выводы и рекомендации по снижению вредных выбросов от работы двигателя на дизеле и биодизеле в атмосферу. У роботі представлено опис результатів експериментальних досліджень екологічних характеристик двигуна із запалюванням від стиснення, що працює на альтернативних видах палива (дизельне паливо, біодизельне паливо в суміші з дизельним паливом, чисте біодизельне паливо і чисте рапсове масло). Наведено результати визначення виділення диму при роботі двигуна з різними видами палива, викиду CO2, СО і СН у вихлопних газах в залежності від потужності двигуна. Викладено висновки і рекомендації щодо зниження шкідливих викидів від роботи двигуна на дизелі і біодизель в атмосферу. The article is devoted to determining the main technological, operational and environmental characteristics of the operation of an internal combustion engine. Research was conducted using classic diesel, pure rapeseed oil, and a mixture of diesel and rapeseed oil in different proportions. The article provides a methodology for experimental research of the main technological, operational and environmental characteristics of the operation of the D-241L direct injection engine on various types of fuel. The qualitative characteristics of the used fuel are described. In the first series of experiments, smoke emission indicators were determined during engine operation at 1000 rpm and 2100 rpm with various types of fuel. It was revealed that the operating mode does not significantly affect the formation of smoke. In the following series of experiments, studies were made of the formation of harmful gases depending on the engine load. The regularities of emissions of carbon monoxide (CO), carbon dioxide (CO2) gases and hydrocarbon (CH) are determined when using various types of fuel. It was found that carbon dioxide emissions are minimal when using a mixture of diesel (25%) and rapeseed oil (75%) in all engine operating modes. The minimum emissions of carbon monoxide and hydrocarbon for this mixture are observed only when the engine is running with a load of 75%. The results obtained allow us to draw the following conclusions. The physic-chemical properties of rapeseed oil differ significantly from the properties of diesel and mixtures. Rapeseed oil is not recommended for a long time to be used in engines with direct injection, since it does not completely burn out. To use rapeseed oil as a fuel for direct injection diesel engines, some modifications are required in their design. When the engine is running on pure rapeseed oil, the gas phase of emissions is higher compared to other types of fuel, which characterize the deterioration of the combustion process of the fuel mixture. Rapeseed oil and its mixture with a diesel engine reduce carbon monoxide and hydrocarbon emissions in exhaust gases at an engine load of 75%.