Перегляд за Автор "Dykha, O."
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Документ Determination of the dynamic hardness of greases as a characteristic of deformation properties in a tribocontact(Хмельницький національний університет, 2022) Dykha, O.; Staryi, A.; Dytyniuk, V.; Dykha, M.; Диха, О.В.; Старий, А.Л.; Дитинюк, В.О.; Диха, М.О.The efficiency of plastic oil is determined by the duration of its retention on the surface. Evaluation of the effectiveness of plastic lubricants depends on their mechanical properties. It is proposed to use the dependence of hardness on time when pressing a spherical indenter as one of the basic characteristics of the mechanical properties of plastic oils. The method of determining the function of oil hardness is based on the mechanics of contact interaction of a solid ball and a plane presented in this work, which has the property of creep according to the flow theory. One of the main methods of testing the deformation properties of plastic lubricants is to determine the number of penetrations. The number of oil penetrations is determined by the depth of indentation of the indenter; more informative for such a process is the ultimate pressure (hardness), which actually reflects the phenomenon of resistance to indenter indentation in the material. For uniform distribution of pressure under a spherical indenter the technique of construction of function of dynamic hardness of plastic materials is defined and on the basis of tests results of construction of dynamic hardness are received. Tests on contact creep of plastic lubricants are carried out, functions of dynamic hardness are received and the analysis of influence of character of change of dynamic hardness on wear processes in the presence of lubricants is carried out. To analyze the influence of deformation properties on the tribological properties of lubricants, comparative tests of the two above-mentioned types of lubricants on a four-ball friction device were performed. It was found that Litol-24 oil has the best wear resistance. The nonlinear period of running-in for this oil is practically absent that, obviously, under the given conditions of tests is connected with more stable in time deformation properties.Документ Experimental installation for wear tests of materials and coatings(Хмельницький національний університет, 2024) Stechyshyn, M.; Dykha, O.; Oleksandrenko, V.; Tsepenyuk, M.; Kurskoi, V.; Oleksandrenko, Ye.On the basis of the analysis of existing tribological testing methodologies, which includes the selection of controlled wear parameters, the influence of the type of friction, contact geometry, surface roughness, the scheme of tribological research, the choice of a machine 2168UМТ for friction testing of materials is substantiated. The friction machine allows you to install three samples at the same time, change the pressure in the contact zone in a wide range, control the moment of friction, the rotation frequency of the counterbody, the number of revolutions (friction path), change the rotation frequency, respectively, the sliding speed, automatically limit the distance traveled and other functions. The method of wear is adopted according to the finger-ring scheme, linear wear is monitored using an indicator rack with a value of divisions of the measuring device of 0.001 mm. To fix the samples on the machine caliper, holders were designed and manufactured, which ensure the self-fixation of the sample on the counterbody - a spherical joint made of the rolling body of the bearing. due to the fact that the samples were pressed against the counterbody with a force corresponding to the nominal contact pressure, they were self-aligned. After the sample was self-assembled, the whole structure was fixed by tightening the nuts. The counterbody is made of a rolling bearing ring, the material is steel SHX15, the hardness of the base is HRC 61. Three devices are mounted on the caliper for permanent lubrication of the running track immediately before the approaching sample. Thus, at certain values of pressure and speed, the mode of marginal friction can be reached, which was marked by a low coefficient of friction.Документ Friction and wear of current-transmitting contact elements of electric transport with the use of metal-graphite composite materials(Хмельницький національний університет, 2023) Kovtun, O.; Dykha, O.The work provides an analysis of research devoted to the problem of manufacturing and operation of current-transmitting elements of electric transport, namely, the durability of contact parts according to operational and tribological characteristics. The work of current-transmitting elements of electric transport consists in the continuous sliding of one element on the surface of another and is accompanied by wear. At the same time, two types of wear are distinguished: mechanical and electrical. It has been established that the correct choice of materials has the greatest impact on reducing friction and wear of electrical contact elements. The basis for this is graphite material, which has the best current-conducting characteristics, but has insufficient strength and wear resistance. Approaches to the creation of materials for electrical contact elements using composite metallographite materials based on copper, aluminum, lead and other materials are analyzed.Документ Influence of lubrication on the friction and wear of car rolling bearings(Khmelnytskyi National University, 2021) Dykha, O.; Makovkin, O.; Posonsky, S.The goal of the work is to develop computational and experimental approaches to determine the wear resistance of friction units with internal contact of cylinders with slip. The scientific novelty consists in taking into account the slip for calculating the friction path and the wear of the cylinders with internal contact and the proposed method for identifying the parameters of the wear law based on the test results. Practical value is the proposed methods to account load, slip and lubrication conditions on the resource for the design of friction units. The dependences for determining the friction path for internal rolling of cylinders have been considered. The design of an experimental setup for studying friction and wear of cylinders with slip has been proposed. Experimental studies have been carried out: paths of friction; wear of surfaces both with a key and without a key; the effect of lubricants on wear has been studied. The form of the wear model is proposed to determine the effectiveness of methods for increasing wear resistance. The method for determining the parameters of the wear law has been implemented based on the test results. The results show the efficiency of copper powder as an additive to a lubricant. It has been established that the wear of cylinders with a key is greater than the wear of cylinders without a key due to different friction paths. A practical example of determining the wear of a car hub shaft using the wear patterns is presented.Документ Investigation of the friction characteristics in the cylindrical sliding tribosystems(2017) Dykha, O.; Sorokatyi, R.; Makovkin, O.; Posonskiy, S.Документ Modern studies of tribological bearing systems: a review(Хмельницький національний університет, 2019) Dykha, O.; Dytynyuk, V.; Posonsky, S.; Zelenska, L.; Дыха, А.В.; Дытынюк, В.А.; Посонский, С.Ф.; Зеленская, Л.И.Sliding bearings are one of the important friction points of modern machines, ensuring their long-term operation. Sliding supports determine the accuracy of the executive movements of the working parts of the machines. Creating and researching reliable and accurate sliding bearings is an important engineering issue. This review presents the results of studies of bearings, published in recent years in specialized scientific journals. The issues of creating efficient structural bearing assemblies, including through the use of new hybrid materials and structures, are considered. Much attention is paid to the problem of bearing wear and reducing the coefficient of friction. Separately considered issues of computer modeling of working conditions and design of structures. Considered modern approaches to the calculated evaluation of bearings, the solution of contact problems. This review allows scientists and engineers to do the right task setting when planning further research on bearing tribo systems.Документ Optimization of technological parameters at discrete strengthening of steel cylindrical surfaces(Хмельницький національний університет, 2024) Dykha, O.; Dytyniuk, V.; Hrypynska, N.; Vychavka, A.The technologies of continuous strengthening of technological surfaces have practically exhausted their capabilities, which calls for the creation of fundamentally new approaches. The application of the principles of discrete-oriented strengthening of tribosystems has wide prospects for improving existing methods of strengthening due to the selection of modes and control of the geometric structure of the surface layer. The essence of the discrete-oriented strengthening method is the application of combined electromechanical processing and electrocontact cementation of cylindrical surfaces. The purpose of the work is to determine the parameters of discrete processing of cylindrical steel parts that are optimal according to the surface hardness criterion. Using the Statistica program, a factorial experiment was implemented according to the Box-Behnken plan, and the results of dispersion and regression analysis of the influence of processing parameters on microhardness were obtained. It was established that the following optimal parameters of DOZ processing are necessary to achieve the maximum values of microhardness (5950 MPa): current strength-500A, force-350 N, contact time-0.3 s.Документ Research on the influence of rolling element geometry on the wear resistance of drilling equipment bearings(Хмельницький національний університет, 2025) Makovkin, O.; Dykha, O.; Valchuk, I.; Kalaczynski, T.The article presents the results of experimental studies of the influence of the geometric parameters of rollers and raceways on the resistance of roller bearings to rolling element rotation and jamming. Failure of bearing assemblies due to roller rotation is a common cause of emergency equipment shutdown, which is accompanied by expensive repairs. The aim of the work was to determine the optimal ratio of roller length to its diameter (l/d) and the influence of raceway diameter (D) on critical wear, which leads to loss of roller stability. The research methodology was based on mathematical experimental design with variation of parameters l, d and D in laboratory conditions when simulating misalignment of the bearing assembly. An empirical relationship was established that quantitatively describes the relationship between roller geometry, raceway diameter and critical wear. The results showed that increasing l/d increases the resistance of the rollers to turning, while an excessive increase in D contributes to the growth of backlash and distortions. The most effective configuration was found to be the one with the maximum length and minimum diameter of the roller at a small value of D. The results obtained can be used for the design improvement of bearing assemblies, in particular in drilling equipment, in order to increase the resource and reliability of their operation.Документ Theory and experiment of tribological test methods(Хмельницький національний університет, 2022) Dykha, O.; Staryi, A.; Getman, M.; Fasolia, V.; Диха, О.В.; Старий, А.Л.; Гетьман, М.М.; Фасоля, В.О.Based on the analysis of the current state of test methods for wear of friction pairs and the need for methods with certain operating conditions, the problem of developing a theory of test methods for wear of friction pairs according to the ball-cylinder scheme was solved, which makes it possible to determine the parameters of wear models and the general characteristics of the wear resistance of materials. It is shown that the type of wear within the range of properties of the friction pair parameters ensures compliance with the basic conditions in contact: materials, lubrication, pressure, speed, temperature, type of movement, and other less significant factors. It has been established that one of the fundamental issues in the development and conduct of wear tests is to take into account the influence of the stationarity of the wear mode at a point. Test methods in steady and unsteady modes (transient mode) are different. The test method should be based on the solution of the contact problem for a friction pair sample-counter-sample. Based on the solution of wear-contact problem for the "ball-cylinder" scheme, a theory has been developed for identifying the parameters of the wear pattern. To solve the inverse problem, a method of approximating function is proposed and implemented. The power approximation of the experimental function after substitution into the resolving equation gives simple expressions for calculating the model parameters. The results obtained make it possible to predict the intensity of wear of tribocouples under given initial operating conditions: according to loads, sliding speed, char acteristics of lubricants and structural materials.Документ Tribological properties of anode-spark coatings on aluminum alloys(Хмельницький національний університет, 2022) Dykha, O.; Babak, O.; Makovkin, O.; Posonskiy, S.; Диха, О.В.; Бабак, О.П.; Маковкін, О.М.; Посонський, С.Ф.It is established that at present the technology of anode-spark coatings in general is well studied. However, the lack of recommendations for the choice of modes of technological processes and tribological characteristics in different operating conditions limit the widespread introduction of this technology. The task of this work was to analyze the processes of anode-spark coatings, improve technology and study the wear resistance of samples processed by this and traditional anode technology. The development of technology for the application of protective coatings on valve metals in the conditions of spark discharge included the choice of electrolyte and mode of operation of the bath: voltage, current density, hydrodynamic conditions and other parameters. Wear resistance tests were performed on a special installation. Structurally, the installation is made in two positions, which allows you to test two samples with different load conditions at a constant sliding speed. The design of the installation implements the friction scheme of the liner shaft. The study of anode-spark coatings in the mode of limiting lubrication was studied in the environment of industrial oil. The wear criterion was the weight wear of the samples according to the results of weight measurements before and after wear. It is established that prolonged electrolysis in the conditions of sparking leads to the formation of anode coatings that exceed in their properties the films obtained by non-sparking oxidation. Comparative studies of the wear resistance of anode-spark coatings and galvanic anode coatings under the same test conditions showed that the wear of anode-spark coatings is almost twice lower for the entire load range. The considered technology is recommended for increase of wear resistance of elements of devices from the aluminum alloys working in the conditions of corrosion and mechanical wear.Документ Vibration diagnostics of machine friction units: analysis of the current state and prospects(Хмельницький національний університет, 2023) Lytvynov, O.; Dykha, O.Vibration diagnostics makes it possible to detect defects in the friction parts of the machine at the early stages of their development, which provides for the repair or replacement of parts before they fail. In this work, an analysis of modern research on the use of vibration diagnostics in tribology is carried out, which includes aspects: vibration diagnostics in technology and tribology; vibration during friction and wear; vibration assessment methods; theoretical approaches in the analysis and modeling of vibrations. It is noted that an important aspect is the development and implementation of theoretical approaches in the analysis and modeling of vibrations, which allows a deeper understanding of the dynamics of friction and wear. This approach makes it possible to develop accurate and adaptive strategies for maintenance and optimization of tribotechnical parameters. It is shown that vibration diagnostics is not only a tool for detecting malfunctions, but also a key element for ensuring the long-term and efficient functioning of friction units of machines. The effective use of vibration diagnostics can significantly reduce maintenance costs, increase the reliability and productivity of equipment, which becomes an indispensable condition for the effective functioning of modern technical systems.Документ Визначення контактного тиску в циліндричній напрямній ковзання з перекосом осей(Хмельницький національний університет, 2024) Вичавка, А.; Диха, О.; Vichavka, A.; Dykha, O.Визначений вплив розмірів напрямної і кута перекосу на величину максимальних контактних тисків у циліндричній напрямній ковзання. Представлена розрахункова схема контакту з перекосом циліндричної напрямної. Для вирішення контактної задачі використовується наступна система вихідних рівнянь: умова рівноваги в контакті, умова суцільності в контакті, геометрична умова і залежність для контактного тиску. В результаті розв’язку системи отримаємо інтегральне рівняння для кута контакту і контактного тиску в будь-якому перерізі напрямної. Інтеграл у загальному рішенні зводиться до елементарних функцій із результатами наведеними в таблиці. Для функції переміщень у вигляді трапеції при заданому куті перекосу та довжині лінії контакту наведені графіки визначення переміщень в контакті і відповідно контактного тиску.Документ Нeat and mass transfer models at boundary lubrication to determine the transition temperatures(Хмельницький національний університет, 2021) Dykha, O.; Staryi, A.; Диха, О.В.; Старий, А.Л.At present, kinetic and thermodynamic methods for assessing the lubricating effect of oils are being increasingly developed. At the limit friction, the reduction of friction and wear of surfaces is due to the ability of the lubricant to form layers of adsorption or chemical origin on the surface. Analytical models of transition temperatures and wear in the limit lubrication mode must be used to mathematically describe the processes in the subsystems and the transition between them. The Fourier equation of thermal conductivity is accepted as the basic calculated dependence. It is assumed that the process of heat propagation under the conditions of formation of lubricating films is not Markovian, i.e. the magnitude of the heat flux is determined by the entire "history" of heat transfer in a certain elementary volume. The equation of motion of a lubricating film over the surface of a body that is being lubricated is obtained from the equation of motion for a Newtonian continuous medium. As a result, nonlinear heat and mass transfer models are obtained to determine the transition temperatures in the formation of boundary lubricating films in the concept of structural-thermodynamic approaches to describe the processes of boundary lubrication of surfacesДокумент Підвищення антифрикційних характеристик поршневих ущільнень компресора кондиціонера автомобіля(Хмельницький національний університет, 2024) Диха, О.; Свідерський, В.; Голенко, К.; Dykha, O.; Svidersrkyi, V.; Holenko, K.Проаналізовано недоліки, що мають місце при застосуванні фторполімерів у вузлі тертя поршневе ущільнення – циліндр компресора кондиціонера автомобіля. Розглянуті перспективні методи модифікації політетрафторетилену і вимоги до його наповнювачів. Проведені експериментальні дослідження підтвердили переваги антифрикційних композиційних фторопластових матеріалів модифікованих комбінованими наповнювачами: вуглецевим і скловолокном, вуглецевим волокном і порошком закису міді або свинцю для вузла тертя поршневе ущільнення – циліндр компресора кондиціонера автомобіля.Документ Розрахункова оцінка зносостійкості матеріалів напрямних ковзання(Луцький національний технічний університет, 2017) Диха, О.В.; Посонський, С.Ф.; Маковкін, О.М.; Вичавка, А.А.; Dykha, O.; Posonsky, S.; Makovkin, O.; Vychavka, A.Запропоновано розрахункові залежності для визначення кінетики зміни трибоконтакних параметрів в процесі зношування для мастильного профілю змінної глибини. Проведений розв`язок зносоконтактної задачі для плоских напрямних ковзання. За базову модель зношування прийнята лінійна залежність від безрозмірних комплексів контактного тиску і швидкості ковзання. Отримана формула для розрахунку зносу напрямних ковзання в залежності від шляху тертя.