Browsing by Author "Korendiy, Vitaliy"

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    Analysis and improvement of two-mass vibrating tubular conveyers with two-cycle electromagnetic drive
    (Publishing House of Lviv Polytechnic National University, 2016) Shenbor, Vladyslav; Koruniak, Petro; Korendiy, Vitaliy; Brusentsov, Volodymyr; Brusentsova, Marta
    The analysis of structure diagrams of the two-mass tubular conveyer with two-cycle electromagnetic drive is carried out in the article. Two methods of designing of the elastic system are considered; calculation formulas for elastic system computation are deduced according to different requirements for the operating parameters of conveyers; the comparative analysis of two types of elastic systems is conducted. The recommendations for designing the lengthy tubular vibrating conveyers are presented. According to the considered structural diagrams of the elastic system the models of the lengthy vibrating conveyers with the transporting distances l =1,5...4 m are developed. On the basis of these models the lengthy vibrotransporting systems with the transporting distance l = 5...30 m were developed, manufactured and applied in industry. The considered systems ensures the transportation of loose materials (porcelain composition, sand etc.) with maximal speeds up to 800 mm/sec and productivities (for tubes with internal diameter D =100 mm) up to 30 tons per hour for. It is reasonable to use both considered schemes of elastic systems for development of vibrating tubular conveyers with electromagnetic drive. The conveyers may be designed in two modifications: overhead and supporting. The obtained dependencies allow optimization of the structure and considering the important technical parameters of conveyers (maximal permissible oscillations amplitude, springs stresses, productivity etc.) in the design phase.
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    Analysis of structure and kinematics of four-bar crank-rocker walkingmechanism
    (Publishing House of Lviv Polytechnic National University, 2015) Korendiy, Vitaliy
    Problems and prospects of using the walking mode for producing motion of robotic systems are considered. Advantages and spheres of the use of mobile robotic systems equipped with walking movers are substantiated. Preferences of cyclic (lever) walking mechanisms are analyzed. The kinematic parameters of four-bar crank-rocker walking mechanism, constructed on the basis of Chebyshov-Umnov mechanism, are accepted as the subject of research. The process of motion of the supporting foot of the walking mechanism is accepted as the object of research. The main aim of the investigation consists in carrying out structure and kinematics analysis of the mentioned mechanism with further derivation of analytical dependencies for calculating kinematic parameters of the supporting foot motion. The special features of the structure of four-bar walking mechanism and theoretical foot loci (paths) are considered. The form of the most reasonable path for further research is established. As a result of carried out structure analysis, it is ascertained that the mechanism consists of two structural groups: that of the first class and that of the second class second order first type. As a result of kinematics analysis, the analytical expressions for calculation of coordinates of the supporting foot hinge of the walking mechanism depending on geometric parameters of the mechanism and the angle of the crank rotation are deduced. The prospects of further investigation under the themes of the paper are analyzed. In particular, the goal function, which may be used for further optimization of structural parameters of the mechanism, is considered and the use of applied software for solving optimization problem is suggested. The optimization problem consists in evaluating such geometric parameters of the walking mechanism which allow the motion of the supporting foot in accordance with the prescribed (specified) path.
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    Combined mechanical systems of anti-storm protection of horizontal-axis wind turbines
    (Lviv Polytechnic Publishing House, 2015) Korendiy, Vitaliy; Vergeles, Vitaliy; Lviv Polytechnic National University
    The necessity of further improving of existent regulation mechanisms is motivated for the purpose of increasing of accuracy of power regulation, effectiveness and reliability of wind turbines functioning in wide range of wind speeds. The prospects of creation of combined mechanical systems are considered, where the possibilities of simultaneous blades turning and folding, blades turning (or folding) and wind-wheel deflection out of wind direction are provided.
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    Derivation of analytical dependencies for determining stiffness parameters of vibration isolators of vibratory machine
    (Lviv Politechnic Publishing House, 2020) Lanets, Oleksii; Kachur, Oleksandr; Korendiy, Vitaliy; Lviv Polytechnic National University
    Problem statement. While designing vibration isolators, the essential attention should be paid to the safety factors such as the levels of vibration and noise, as well as to the material and the structure of isolators. In major vibratory technological equipment, there are used full-metal vibration isolators, which can be designed in the form of coil (cylindrical, conical, helicospiral) or flat (leaf-type, disc-type) springs. The problems of stress-strain analysis of metal springs used for vibration isolation of various vibratory equipment are of urgent interest among the designers and researcher. The engineering techniques of step-by-step calculation of full-metal vibration isolators of different types of vibratory technological machines are not thoroughly presented in the modern information resources. Purpose. The present paper is aimed at developing and implementing the detailed algorithm of determining the stiffness parameters of the metal coil springs used for vibration isolation of large-scale vibratory machines. Methodology. The investigations are carried out using the basic laws and principles of solid mechanics and theory of vibrations. The calculations were conducted using MathCAD software; the computer simulation of the spring’s stress-strain state was performed using SolidWorks software. Findings (results) and originality (novelty). The improved design of the vibratory conveyer-separator is considered. The engineering technique of calculating the passive vibration isolators of various vibratory equipment designed in the form of metal coil springs is developed. The proposed technique is implemented while designing the vibration isolation system of the vibratory conveyer-separator. The system’s operational characteristics are determined, and the computer simulation of the springs stress-strain state is carried out. Practical value. The proposed design of the vibratory conveyer-separator can be implemented in various industries (machine-building, chemical, pharmaceutical, food-processing, construction, mining, metallurgy, textile industries etc.) for conveying different loose, bulky and piecewise products, and separating them into fractions of different sizes. Scopes of further investigations. While carrying out further investigations, it is necessary to analyse the influence of the proposed design of vibratory conveyer-separator on the foundation during its operation, and to consider the necessary of applying the additional fixation systems.
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    Design and operational peculiarities of four-degree-of-freedom double-legged robot with pneumatic drive and turning mechanism
    (Lviv Politechnic Publishing House, 2020) Korendiy, Vitaliy; Zinko, Roman; Lozynskyy, Vasyl; Havrylchenko, Oleksandr; Lviv Polytechnic National University
    Problem statement. Mobile robots are of significant interest among scientists and designers during the last several decades. One of the prospective drives of such robots is based on pneumatically operated walking (stepping) system with no use of electric, heat, magnetic or other types of energy. This allows the use of pneumatically-driven robots in the cases when the use of other energy sources is prohibited (e.g., in some gaseous or fluid mediums). At the same time, the walking (stepping) type of moving increases the manoeuvrability and cross-country capability of the mobile robot, and decreases the harmful effect of its interaction with the supporting surface (e.g., the fertile soil surface) in comparison with wheeled or caterpillar drives. Purpose. The main purpose of this research consists in substantiation of structure and parameters of pneumatic system of four-degree-of freedom mobile robot with orthogonal walking drive and turning mechanism. Methodology. The research is carried out using the basic laws and principles of mechanics, pneumatics and automation. The numerical experiment is conducted in MathCAD software; the computer simulation of the robot’s motion is performed using SolidWorks software; the modelling of the pneumatic system operation is carried out in Festo FluidSim Pneumatic software. Findings (results) and originality (novelty). The improved structure of the mobile robot with orthogonal walking drive and turning mechanism is proposed. The pneumatically operated system ensuring the robot’s curvilinear motion is substantiated. Practical value. The proposed design of walking robot can be used while designing industrial (production) prototypes of mobile robotic systems for performing various activities in the іnvironments that are not suitable for using electric power or other types of energy sources. Scopes of further investigations. While carrying out further investigations, it is necessary to design the devices for changing motion speed of the robot and the height of lifting of its feet.
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    Development of experimental horizontal-axis wind turbine with sail-type blades
    (Lviv Polytechnic Publishing House, 2016) Korendiy, Vitaliy; Bushko, Oleksandr; Barabash, Volodymyr; Lviv Polytechnic National University
    The analysis of structure of horizontal-axis wind turbine with sail-blades is carried out. Its operational features are overviewed. The technique of experiment replication is developed. The scopes of further investigations are presented.
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    Improvement of structural diagrams of vibratory separators with electromagnetic drive
    (Видавництво Львівської політехніки, 2017-12-23) Korendiy, Vitaliy; Shenbor, Vladyslav; Shenbor, Yurii; Lviv Polytechnic National University
    The features of construction of structural schemes of vibratory separators based on vibratory conveyors with electromagnetic drive are considered. The structural diagram of the vibratory separator developed on the basis of three-mass oscillatory scheme with the possibility of transporting the mixture and the separated component by vibratory transportation in opposite directions is proposed, and the device operation is substantiated. The main criteria of separation efficiency are presented. The possible directions of effective implementation of vibratory separators are suggested.
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    Mobile robotic systems with walking movers and mechanisms of orientation
    (Lviv Polytechnic Publishing House, 2015) Korendiy, Vitaliy; Bushko, Oleksandr; Denderys, Nazar; Lviv Polytechnic National University
    The expediency and areas of use of walking machines are substantiated. Three simplest diagrams of cyclic (lever) walking mechanisms (four-link, four-link with possibility of changing the position of the rocker arm rotation axis, six-link) are considered. Principal diagram of the lever mechanism of orientation of walking module with two cyclic movers is propounded and its operating features are analyzed.
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    Modellingand simulation of pneumatic system operation of mobile robot
    (Lviv Politechnic Publishing House, 2020) Korendiy, Vitaliy; Kachur, Oleksandr; Havrylchenko, Oleksandr; Lozynskyy, Vasyl; Lviv Polytechnic National University
    Problem statement. Mobile robots are currently of significant interest among researchers and designers all over the world. One of the prospective drives of such robots is equipped by a pneumatically operated orthogonal system. The processes of development and improvement of orthogonal walking robots are significantly constrained because of the lack of an open-access comprehensive scientific and theoretical framework for calculating and designing of the energy efficient and environmental-friendly pneumatic walking drives. Purpose. The main purpose of this research consists in the kinematic analysis, motion modelling and pneumatic system simulation of the mobile robot with an orthogonal walking drive. Methodology. The research is carried out using the basic laws and principles of mechanics, pneumatics and automation. The numerical modelling of the robot motion is conducted in MathCad software. The computer simulation of the robot kinematics is performed using SolidWorks software. The operational characteristics of the robot’s pneumatic system are investigated in Festo FluidSim software. Findings (results) and originality (novelty). The improved design of the mobile robot equipped by the orthogonal walking drive and turning mechanism is thoroughly investigated. The motion equations of the orthogonal walking drive are deduced, and the graphical dependencies describing the trajectories (paths) of the robot’s feet and body are constructed. The pneumatically operated system ensuring the robot rectilinear and curvilinear locomotion is substantiated. Practical value. The proposed design of the walking robot can be used while developing industrial (production) prototypes of mobile robotic systems intended for performing various activities in the environments that are not suitable for using electric power. Scopes of further investigations. While carrying out further investigations, it is expedient to design the devices for changing the robot locomotion speed and controlling the lifting height of its feet.
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    Optimization of structure of sorting vibratory separators
    (Lviv Politechnic Publishing House, 2017-01-01) Shenbor, Vladyslav; Korendiy, Vitaliy; Brusentsov, Volodymyr; Lviv Polytechnic National University, Lviv, Ukraine
    The problem of substantiation of operational efficiency of vibratory separators designed on the basis of vibratory hopper feeders with electromagnetic vibrations exciters and with conic working bowls is considered in the article. The complex of factors influencing the accuracy and productiveness of separation of coins and disk-shaped products on two or more fractions is overviewed. New models of structures for the effective solution of separation problems are proposed. The design of a highly-efficient and high-performance separator with independent oscillations disturbance is described. The results of experimental investigations of vibratory transportation in elliptical modes of vibrations and of the study of separation efficiency are presented. The recommendations that developers and researchers of such devices may use are given.
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    Simulation modelling of dynamic processes due discontinuous frictional treatment of the flat surfaces
    (Lviv Politechnic Publishing House, 2020) Gurey, Volodymyr; Korendiy, Vitaliy; Kuzio, Ihor; Lviv Polytechnic National University
    Friction treatment refers to surface strengthening (hardening) methods using highly concentrated energy sources. In the course of this processing in the surface layers of the processed surfaces of parts the strengthened layer with nanocrystalline structure is formed. The formed layer has specific physical, mechanical, chemical properties, as well as improved performance properties, which are significantly different from the base metal. A highly concentrated energy source is formed in the contact area of the tool-part due to the high-speed friction (60–90 m/s) of the tool on the treatment surface. Frictional treatment of flat parts according to the kinematics of the process is similar to grinding. The strengthening process was carried out on an upgraded surface grinder. The tool is a metal disk made of stainless-steel. Transverse grooves are formed on the working surface of the tool to intensify the process of forming a strengthened (reinforced) layer with a nanocrystalline structure. The grooves form additional shock loads in the contact area of the tool-treatment surface of the part. These shock loads increase the shear deformation of the metal of the parts’ surface during treatment, which affects into formation the quality parameters of the parts’ surface and surface layer. To study the friction treatment process, the calculation scheme of the elastic system of the machine was developed. A simulation model for the study of dynamic processes that take place during the friction treatment of flat surfaces was built. This model gives possibility to determine the displacements and velocities of the machine table on which the part is fixed and the tool, and to determine their mutual displacement and also calculate the reaction of the machine table.
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    Structural and kinematic synthesis of the 1-Dof eight-bar walking mechanism with revolute kinematic pairs
    (Lviv Politechnic Publishing House, 2017-10-19) Korendiy, Vitaliy; Lviv Polytechnic National University
    Problem statement. The use of existing and the most widespread drives (wheeled and caterpillar one) is sometimes limited by complicated operational conditions while moving on rough terrain. The mentioned drives require a relatively flat surface to be operated effectively. A rocky or a hilly terrain imposes the demand of the use of alternative types of drives, in particular, walking ones. Purpose. In this paper, there will be proposed and analysed one of the possible structures of the walking mechanism for mobile robotic system to be used on rough terrain. Methodology. While carrying out the investigations, the structural and kinematic synthesis of the eight-bar hinge-lever walking mechanism has been performed using the well-known methods of the Theory of Machines and Mechanisms, in particular, the method of closed vector loops. In order to conduct experimental investigations and simulation of the mechanism motion, the applied software SolidWorks and MapleSim has been used. Findings (results). The structure and geometrical parameters of the eight-bar walking mechanism have been synthesized with the aim to ensure the required trajectory and kinematic characteristics of the supporting foot motion. Originality (novelty). The analytical dependencies describing the trajectory of each hinge of the analysed walking mechanism have been derived and the kinematic optimization synthesis problem has been solved. This allowed to substantiate of the mechanism’s geometrical parameters and to analyse its kinematic characteristics. Practical value. The proposed structure of the walking mechanism can be effectively used in various mobile robotic systems and in transporting and technological machines in order to ensure the possibility of their use on rough terrain where there is no ability to use wheeled and caterpillar drives. Scopes of further investigations. While carrying out further research, it is necessary to analyse the influence of the weight coefficients on the solution of the optimization problem, as well as to take into account the necessity of changing the step length and the foot lifting height during the process of walking according to the surface obstacles sizes.
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    Structure analysis of sixand eight-link walking mechanisms
    (Lviv Polytechnic Publishing House, 2016) Korendiy, Vitaliy; Skripnik, Roman; Khomych, Ihor; Lviv Polytechnic National University
    Structure analysis of six- and eight-link walking mechanisms is carried out. Structure formulas of corresponding mechanisms are formed. The recommendations for further kinematic analysis method selection are presented.
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    Substantiation of parameters and analysis of operational characteristics of oscillating systems of vibratory finishing machines
    (Lviv Politechnic Publishing House, 2017-10-19) Korendiy, Vitaliy; Zakharov, Viktor; Lviv Polytechnic National University; ISKRA PJSC
    The calculation diagrams of oscillating systems and operation features of vibratory finishing machines are considered. The mathematical models of three-mass and four-mass oscillating systems are presented. The amplitude values of the oscillating masses displacements are derived. The functions of inertial and stiffness parameters optimization are formed. The optimization problems are solved with a help of MathCAD software. On the basis of synthesized inertial and stiffness parameters, the amplitude-frequency characteristics of the oscillating systems of vibratory finishing machines are formed and analyzed. In order to verify the validity of the proposed theoretical approaches, the simulation of the mathematical model of the oscillating system motion is carried out by means of numerical solving of the system of differential equations of the oscillating masses motion. The proposed structural diagrams and the operation schemes of the vibratory finishing machine, as well as the derived analytical formulas may be used by designers, researchers and technologists while improving existent and developing new equipment for vibro-finishing treatment.
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    Substantiation of structure and parameters of pneumatic system of mobile robot with orthogonal walking drive
    (Видавництво Львівської політехніки, 2019-03-20) Korendiy, Vitaliy; Zinko, Roman; Muzychka, Diana; Lviv Polytechnic National University; Dniprovsky State Technical University
    Problem statement. Mobile robots have awoken a large interest between scientists and designers in the last few years. One of the prospective drives of such robots is based on pneumatically operated system with no use of electric, heat, magnetic or other types of energy. Purpose. The main purpose of this research consists in substantiation of structure and parameters of pneumatic system of mobile robot with orthogonal walking drive. Methodology. The research is carried out using the basic laws and principles of mechanics, pneumatics and automation. The numerical experiment is conducted in MathCAD software and computer simulation of the robot’s motion is performed using SolidWorks software. Findings (results) and originality (novelty). The improved structure of the mobile robot with orthogonal walking drive is proposed. The pneumatically operated system ensuring the robot’s motion is substantiated. Practical value. The proposed design of walking robot can be used while designing industrial (production) prototypes of mobile robotic systems for performing various activities in the environments that are not suitable for using electric power. Scopes of further investigations. While carrying out further investigations, it is necessary to ensure the possibility of changing motion direction of mobile robot by means of pneumatic drive. In addition, it is expedient to design the devices for changing motion speed of the robot and the height of lifting of its feet.
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    Substantiation of the shape of a solid oxide fuel cell anode using the stress-strain and shape-dependent crack deceleration approaches
    (Видавництво Львівської політехніки, 2019-03-20) Kuzio, Igor; Vasyliv, Bogdan; Korendiy, Vitaliy; Borovets, Volodymyr; Podhurska, Viktoriya; Lviv Polytechnic National University; Karpenko Physico-mechanical Institute of the NAS of Ukraine
    Stress and strain distributions in the YSZ–NiO spheroidal shape anode-substrate for a solid oxide fuel cell (SOFC) under pressure of operating environment were calculated using the finite element analysis. The features were then compared with ones of the cylindrical shape anode. The radii ranges for the cylindrical and spheroidal (segments of a sphere) parts of the anode ensuring its improved deformation resistance and more uniform stress distribution were suggested. Based on the calculations, an anode of the cylindrical shape with top and bottom convex surfaces (a spheroidal shape anode), with the spheroid to cylinder radii ratio R / Rc in the range from 5 to 20 is suggested. Itsspecific volume V / Sc isin the range from 1 to 2.5 mm. The stressesin the most dangerous areas (i. e. along the axis and the closed-loop fixing) and maximum strain, caused by external gas pressure on the anode working surface, are decreased by 10–30 % and 20–40 % respectively as compared to an anode of the cylindrical shape of the same radius and volume features. This increases the lifetime of a solid oxide fuel cell. A three-dimensional curve of intersection of the surfaces of stress distribution in the anode along its axis and the closed-loop fixing was approximated which displays the values of balanced stresses depending on V / Vc and R / Rc parameters. Also, the advantage of the spheroid shaped SOFC anode-substrate over conventional flat one was substantiated using a shape-dependent crack deceleration approach.
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    Substantiation of usage expediency and analysis of exploitation problems of low-power wind turbines
    (Lviv Polytechnic Publishing House, 2015) Korendiy, Vitaliy; Vergeles, Vitaliy; Lviv Polytechnic National University
    Wind energy is considered as one of the most perspective, developed and ecologically clean energy resource. Nevertheless, it is associated with several harmful factors which influence environment. That’s why basic causes and zones of vibration initiation in wind turbines, as well as negative vibratory and acoustic factors of wind turbine influence on natural beings, are analyzed. In conclusion it is substantiated that the ecological problems of low-power wind turbines may be neglected and they should be widely used for economic development and energy independence improvement of our country.
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    Technological equipment for finishing treatment
    (Lviv Polytechnic Publishing House, 2016) Gavrilchenko, Oleksandr; Zakharov, Viktor; Korendiy, Vitaliy; Lviv Polytechnic National University; PAT “Iskra”
    The known methods of lap finishing (lapping) of vibrating finishing machines with circular trajectories of lap oscillations are analyzed. The theoretical overview of lap finishing (lapping) with the laps placed in the area of circular sector is presented in this paper.
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    Two-mass vibrating conveyer with nonparallel flat springs
    (Publishing House of Lviv Polytechnic National University, 2016) Koruniak, Petro; Nishchenko, Iryna; Shenbor, Vladyslav; Korendiy, Vitaliy
    The analysis of operation of vibrating conveyers with nonparallel placement of flat springs is carried out. The motion of mechanical oscillating system is investigated. The structure of the supporting unit for flat springs fastening is propounded. This structure allows simplifying of setting-up of two-mass vibrating conveyers with the aim to ensure the effective operation. The models of conveyers with nonparallel placement of springs, providing the accurate calculations of rigidities and angles of flat springs inclinations, considerably simplify the structures of conveyers and their setting-up to ensure the prescribed angles of vibrations. The proposed structure of fastening of flat springs ends allows increasing of operation efficiency of the two-mass vibrating conveyer. Due to such setting-up of the equipment it is possible to compensate some of its theoretical and structural faults. On the basis of presented investigations, it is planned to develop the three-mass models of conveyers-separators with transporting of separated components in different directions.
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    Ways of improvement of operational efficiency of hopper devices
    (Publishing House of Lviv Polytechnic National University, 2016) Koruniak, Petro; Shenbor, Vladyslav; Korendiy, Vitaliy; Bezpalov, Anatoliy; Brusentsov, Volodymyr
    The operation of hopper devices, which are used in industry, civil engineering, agriculture and transport, is analyzed on the article. The external factors, which influence the process of charging, storing and discharging of loose cargo (freights) from hopper tanks, are overviewed. The subject of research of presented paper is the improvement of mechanisms of fracturing of products hangs-up (bridges) in hoppers at the stage of designing and setting up of hopper devices. In order to solve the stated problem the schemes of bridges fracturing and the structures of devices for debarment of products bridging and their uniform outflow from the hopper tank are proposed. The proposed schemes are based on the principles used in development of vibratory machinery with mechanical, cam and electromagnetic vibratory principles of structures forming. For cam spring device of bridges fracturing the technique of calculation of stiffness of elastic system and of the necessary forces for performing of technological process of bridges fracturing is presented and the recommendations for choosing of the stiffness of the system of elastic elements are suggested. For the hoppers with spring and electromagnetic blocks of bridges fracturing and of metered (batched) feeding of products the structural diagrams of devices are presented and the recommendations for usage of various modifications of devices are suggested. The influence of parameters of flat spring elements on the efficiency of devices operation is overviewed. The structural diagrams of devices with one-cycle and two-cycle electromagnetic vibration exciters and the modifications of elastic systems are considered. the structural diagram of the production prototype of the hopper feeder is presented. The materials of the article, the proposed structural diagrams, the operation scheme of the hopper feeder and the derived analytical formulas may be used by designers, researchers and technologists while improving of existent and developing of new devices.