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Item type:Наукова стаття, Influence of Technological Methods of Processing on Wear Resistance of Conjugated Cylindrical Surfaces(Springer, Cham, 2021) Zablotskyi, Valentyn; Tkachuk, Anatolii; Moroz, Serhii; Prystupa, Stanislav; Svirzhevskyi, KostiantynWear of any tribological pair leads to malfunction or failure of the entire mechanism. It is known that the process of wear of friction pairs occurs in three periods: running-in, normal wear, accelerated wear (destruction). Working surfaces of parts that are formed in the manufacturing process receive micro geometric characteristics (roughness, undulation), according to the regulated technological norms. These characteristics describe the properties of the technological surface topography. However, quantitative micro geometric parameters change as they evolve during running-in, and the surface receives a new operational relief that is stable for a long time during normal wear. It is an operational relief of conjugate surfaces that characterizes the qualitative properties of parts for a long period of operation. The running-in process, which is based on complex mechanical, physical, and chemical processes, determines the overall wear resistance of parts. After this period, the physical, mechanical, and geometric characteristics of the surface acquire optimal values corresponding to the operating conditions. Rational performance characteristics during normal wear can self-sustain, and they are continuously reproduced independently in the same values. This state of the surface layer is observed before the beginning of the third stage of the life cycle. Traditionally, to ensure regulated micro geometric characteristics of the working surfaces used grinding, smoothing, and lapping diamond pastes. At the present stage of development of equipment and technology in a row with the mentioned finishing operations, there is an operation of high-speed turning, which allows reaching high purity of surfaces with the lowest cost of the technological process.Item type:Наукова стаття, Methods of Evaluating the Wear Resistance of the Contact Surfaces of Rolling Bearings(2021) Svirzhevskyi, Kostiantyn; Zabolotnyi, Oleg; Tkachuk, Anatolii; Zablotskyi, Valentyn; Cagáňová, DagmarIn modern conditions of development of mechanical engineering, high priority is given to experimental and material science aspects of assessing the wear resistance of conjugate friction surfaces, which consist of the selection of materials with high wear resistance characteristics. However, this way, you can only reduce the intensity of the wear process, but not control the wear process itself and, most importantly, the changes in the state and performance of the mating surfaces that occur as a result of the wear process. The durability of machines is laid down at the design stage and depends on the design scheme, materials used, lubricants, and other factors. An increase in the durability of mated machine parts is impossible without creating modern engineering methods for calculating wear resistance, which would consider the physical and mechanical characteristics of materials (friction pairs, modes of operation of the load node, and angular velocity), external friction conditions (environment, and lubrication), as well as the design and technological features of the friction interface. During the wear of two contiguous bodies, the unevenness of one surface is exposed to the unevenness of the other surface. In this case, the irregularities of the more durable material act similarly to the abrasive elements, cutting off the thin chip from the micro-irregularities of the surface of the less durable material. At the same time, the irregularities that cut this chip wear themselves out, just as cutting abrasive tools wear out.Item type:Наукова стаття, Modeling the Dynamics of Centerless Mortise Grinding on Rigid Supports(2025) Chalyj, Vasyl; Moroz, Serhii; Tkachuk, Anatolii; Zablotskyi, Valentyn; Zabolotnyi, OlegThe paper examines the influence of the dynamic parameters of the machine and the geometry of the adjustment of rigid supports on the formation of undulations of the surfaces of roller bearing rings. A complex mathematical model of the machine tool system for centerless mortise grinding was developed, and the influence of the dynamic parameters of the machine tool and the geometry of the setup of rigid supports on the formation of undulations of the processed surfaces was analyzed. The SWaAGL-50 mortise centerless grinding machine’s technological system is presented as a linear mechanical model, and the elastic movements along the ОХ axis are considered. Based on the equations of kinetic and potential energies compiled in the form of Lagrange, the equations of motion of the relevant elements of the technological system were obtained. The formula of the dynamic accuracy function was found, which characterizes the inconsistency of the movement of the grinding wheel and the part.Item type:Наукова стаття, The Structure of Automated Control Systems for Precision Machining of Parts Bearing(2022) Trokhymchuk, Ivanna; Svirzhevskyi, Kostiantyn; Tkachuk, Anatolii; Zabolotnyi, Oleg; Zablotskyi, ValentynOne of the ways to improve the quality of bearing parts is the introduction of automatic control systems to improve the technological reliability of machines and increase the accuracy of machining of roller bearing rings. A significant advantage of these systems is that it is possible to compensate for technological factors by cheaper means compared to such as increasing the rigidity of the technological system, processing in modeswith lower productivity, processing using more passes, usingmanualmethods to compensate for wear of cutting tools, maintaining the required rigidity of the machine and the accuracy of its elements through periodic repairs. These methods are associated with either a loss of cyclical productivity or a significant loss of unproductive nature. Therefore, the errors of automated control systems should be considered as processing errors or as a scattering field of the dimensions of parts manufactured on a machine equipped with an automatic control system for precision machining. The share of error of the most automated control system in the total balance of the total size error is quite small and does not exceed 10…20%. The task of improving the accuracy and ensuring stability in technological systems is complex, so it is solved only by a comprehensive method by improving the accuracy of all elements of the technological system. Thus, automated control systems for precision machining of bearing parts is one of the main subsystems of flexible automated production in the concept of Industry 4.0.Item type:Наукова стаття, ЕLECTROMAGNETIC FIELD EQUATIONS IN NONLINEAR ENVIRONMENT(2024) Lyshuk, Viktor; Tkachuk, Anatolii; Zablotskyi, Valentyn; Selepyna, YosypThe paper proposes electromagnetic field equations from the point of view of their adaptation to numerical methods. Maxwell'sequations with partial derivatives are used, written concerning field vectors, which most fully reproduce the picture of physical processes in electrical engineeringdevices. The values of these vectors provide comprehensive information about the field at any spatio-temporal point. The concept of creating mathematical models of electrical devices adequate to physical processes has been developed. Mathematical transformations are carried out according to the rulesof differential calculus. Dynamic processes in the elements of electrotechnical devices were analyzed using the apparatus of mathematical modeling.An algorithm for implementing differential equations with partial derivative numerical methods using computer simulation was implemented. The obtained results made it possible to understand the nature of electromagnetic phenomena in nonlinear media. The paper provides calculations of the field parameters in a flat ferromagnetic plate and the groove of the rotor of an electric machineItem type:Наукова стаття, MODELLING OF DYNAMIC MODES IN A DC MOTOR FOR ELECTRIC VEHICLE(Polytechnika Lubelska, 2026) Lyshuk, Viktor; Tkachuk, Anatolii; Moroz, Serhiy; Yevsiuk, Mykola; Khvyshchun, Mykola; Prystupa, Stanislav; Zablotskyi, ValentynThe paper investigates mathematical models of a DC electric motor with independent excitation for electric vehicles and PWM as a speed control method. Differential equations of electromechanical state are written in normal Cauchy form. This representation simplifies the computational process, since integration is carried out by the explicit numerical method of Runge-Kutta of the fourth order, which is simpler than implicit and more accurate than single-step explicit methods. The symbolic programming language Force 2.0, which is a variant of the Fortran language, is used for modelling. Compared to mathematical packages of simulation modelling, it is convenient in terms of low time costs for compiling the program itself, since the program includes model equations together with initial conditions, a numerical method, and an integration procedure. The developed models take into account electromagnetic couplings of the motor's electrical circuits and make it possible to simulate dynamic operating modes. Such models can be used to analyse the operation of motors both autonomously and as an element of an electromechanical system, including valve converters. The operation and transient modes of a DC motor are simulated, the simulation results are given, and their analysis is presented. The results confirmed the correctness of the chosen approach to modelling and numerical methods, as well as compliance with the classical theory of electric machines.Item type:Наукова стаття, METHOD FOR EVALUATION QUALITY PARAMETERS OF TELECOMMUNICATIONS SERVICES(2022-06-30) Zablotskyi, Valentyn; Selepyna, Yosyp; Lyshuk, Viktor; Yakymchuk, Natalia; Tkachuk, AnatoliiCurrently, cellular networks have become widespread, the operators of which simultaneously use the infrastructure of the second generation GSM networks, DCS to build third generation W-CDMA networks that provide broadband multiple access with code division. At the same time,the problem of providing high-speed Internet connections is exacerbated due to the growing volume of data of diverse types transmitted over the Internet. When testing the entire network coverage area, the total number of voice calls increases, so a method of long-term measurement of bit rate of information transmission via wireless communication channels is proposed, which does not increase the service information in the network.Mathematical modelingof Internettraffic consumption using the proposed measurement method is performed and entropy estimates of information channel bandwidthare given.