Reporter of the Priazovskyi State Technical University. Section: Technical sciences

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Authors: M.V. Margulis, Y.Y. Kostenko

Relevant scientific and technical problems in relation to mechanical engineering is development of new technological processes that make it possible to achieve high accuracy and durability of machine parts that meet the requirements imposed on them. So it is important to develop a new method to make a flat gear teeth by plastic deformation of the ingot. The article deals with the actual problem of improving productivity and quality of plane wheels teeth that are widely used in advanced wave, planetary and other transmissions. A progressive method to produce flat gear teeth gear by plastic deformation of the ingot with two knurl rollers alternately moving reciprocally in the direction not intersecting the axis of the ingot mounting surface has been described in the article. The working surface of the rollers corresponds to the resulting shape of the teeth. The schemes of the teeth installing and knurling have been shown. The necessary material and the heat treatment of the knurling tools have been described. Its use will significantly increase the wear resistance of the working surfaces of the teeth and their durability as well as to increase productivity and its manufacturing costs. The material of the rollers is BC15steel. The surface layer of the knurling tools was subjected to nitration, surface hardness being up to 65 HRC. Knurling is made in the5236P shaper suited for this purpose

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Authors: M.V. Margulies, R.A. Islamgeriev

The analysis of the existing lathe devices for machining of eccentric details and the reasons for the development of a new universal machine device– a shifting lathe center-have been described in the article. The device design, its operating principle, the main parts functions and elements of the case were described and illustrated One of the most complicated cases of eccentric shaft turning, that is turning design and scheme of the eccentric shaft of precessional harmonic drive with intermediate rolling bodies when the proposed device was used was described in the article. The shifting lathe center can reduce the complexity of the machine tool for turning eccentric shafts configuration. The ability to install the shifting center in the tailstock and headstock of the lathe, and the availability of the leash makes it possible to turn various eccentric parts, conical surfaces, to apply the device to compensate for the emerging taper in cylindrical shafts processing. All the above mentioned makes the device universal. The specific feature of this device is the use of a ball center and the connection of the centering element with the adjusting screw by a fine thread screw, this increasing the precision machining. The protective cover of the device makes it possible to reduce the chance of possible injury from protruding parts of the device, namely the leash and the centering element

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Authors: E.I. Ivanov, V.V. Vavilkina

This article describes the processing optimization and minimizing the number of tool changes. Two versions for setting the processing scheme, according to the rules for processing scheme setting for the «processing center» machines were offered. In the first version, according to the classical technology processing of each hole is carried out over all the passes, providing for the required accuracy of sizes and shapes. In the second version the number of tool changes is minimized. This method consists of dividing all the holes into groups according to their diameters. All the holes of the same diameter are processed over one pass; then the tools are changed and the holes of some other diameter are processed and so on. Let us consider the optimization problem. The traveling salesman problem - is one of the most famous problems in the theory of combinatorics. The problem is as follows: a travelling salesman (hawker) must find the most advantageous route coming out of a town and visiting all other towns from 2,3,…to...n just once in an unknown order and come back to the first town. The distances between all the towns are known. It is necessary to determine in what order the Salesman must visit the towns so that the route should be the shortest. There exists just one absolutely precise algorithm - sorting options. This option is the longest, so the most inefficient. There are also simpler methods to solve the traveling salesman problem: the branch and bound algorithm and ant colony method and method of genetic algorithms

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Authors: Levitskaya T.О.

Assessment of the relative error in the sessile drop method automation. Further development of the sessile drop method is directly related to the development of new techniques and specially developed algorithms enabling automatic computer calculation of surface properties. The sessile drop method mathematical apparatus improvement, drop circuit equation transformation to a form suitable for working, the drop surface calculation method automation, analysis of relative errors in the calculation of surface tension are relevant and are important in experimental determinations. The surface tension measurement relative error, as well as the error caused by the drop ellipsoidness in the plan were determined in the task of the sessile drop automation. It should be noted that if the drop maximum diameter (l) is big or if the ratio of l to the drop height above the equatorial diameter(h) is big, the relative error in the measurement of surface tension by sessile drop method does not depend much on the equatorial diameter of the drop and ellipsoidness of the drop. In this case, the accuracy of determination of the surface tension varies from 1,0 to 0,5%. At lower values the drop ellipsoidness begins to affect the relative error of surface tension (from 1,2 to 0,8%), but in this case the drop ellipsoidness is less. Therefore, in subsequent experiments, we used larger drops. On the basis of the assessment of the relative error in determining the liquid surface tension by sessile drop method caused by drop ellipsoidness in the plan, the tables showing the limits of the drop parameters (h and l) measurement necessary accuracy to get the overall relative error have been made up. Previously, the surface tension used to be calculated with the relative error in the range of 2-3%

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Authors: V.B. Strutinsky, O.A. Іschenko, V.P. Grishko, D.A. Vorobyov

The restoration of slide rest guides of the automatic lathe PUB 130 was made by using a polymeric material in the laboratory, and the measurements of the rest displacement strength were made on a specially created experimental stand with the ADC and the PC and subsequent determination of the coefficient of friction. The performed experiments revealed that in the speed range of saddle feed from 0,0228 to 0,075 m/s, the coefficient of friction is within 0,047-0,055. At the same time, the transition to the low-feed (0,0005-0,0022 m/s) results in to marked increase of the friction coefficient and the rest hopping movement. However, this phenomenon is likely due to the fact that elastic tie in the form of steel beam with tensometers was put into the feeder of the rest. This explanation let us hope that, with rigid connection of the drive and the rest such a phenomenon will not take place and the value of friction will not differ substantially from the friction obtained at high speeds. The obtained results make it possible to consider the use of a polymer material to be the optimal way to restore worn-out machines

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Authors: S.V. Burmistrov, O.M. Panasko

Steady improvement of microelectronics necessitates deeper understanding of existing methods for discrete structures synthesis, as well as development of new ones. Сombinational circuits of digital blocks are an important class of discrete structures, and Boolean functions are the mathematical models of their functioning. The purpose of this paper is to describe an alternative method of Boolean functions with a large number of arguments minimization. The method is implemented basing on the decomposition of Boolean functions through reducing the value of the basic factor K. Shannon’s decomposition of Boolean functions means Boolean functions decomposition into two summands with respect to some i-argument. The ratio between the number of arguments in informing and in the basic parts of each series member is determined by coefficient K. K is the number of arguments, which is part of the series member basis. The value of K is the criterion of minimizing of the logic equations of Boolean functions y=f(x1,x2,x3,…,xn). The basic factor K is optimal if its informing part value is equal to Qi=1 or Qi=0. Decomposition of Boolean functions does not always result in the minimal form of Boolean functions. It provides a consistent decomposition of Boolean functions, and arguments are essentially equal. Therefore a method of parallel decomposition is proposed in this article. This method is based on decomposition of Boolean functions by simultaneous changes in all the arguments of the basic factor K. Parallel decomposition process consists of two stages. In the first stage, the full list of all the basic parts -Φi with the optimal value of the basic factor K are determined. In the second stage on the basis of Φi complete list of answers is formed. The paper provides a detailed description of the parallel decomposition algorithm for the minimization. Parallelization of the minimization process accelerates the whole process. The software for the minimization of Boolean functions with a large number of arguments on the basis of the described algorithm has been developed. Parallelization process, which is offered for the longest stages of the minimization process makes it possible to obtain minimal forms of Boolean functions by utilizing multiprocessor systems in a relatively short period of time. This has a positive effect on the speed of the digital blocks logical design

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Authors: O.D. Razmyshlyaev, O.M. Serenko, P.O. Vydmysh, M.V. Ageeva

A computation method to determine the induction minimum level of the stationary transverse magnetic field (TMF) has been offered; given the field removing drops from the butt ends of electrodes 3, 4, 5mm in diameter that results in an increase of the electrodes melting productivity. Research has shown that building up under transverse magnetic field (TMF) results in the slant of the butt ends of the electrode, and TMF induction increasing the slant angle in relation to the horizon increases. The computation method takes account of the slant on the butt end of the electrode. The method of balance of the followings integral forces, acting on a drop at building up under TMF is used in the computation method: electromagnetic force resulting from building-up current in the drop and TMF induction transverse constituent interaction; the force and the drop weight force. The drop on the electrode butt end was approximated as a semiellipsoid. It has been stated that at the building-up current is equal to 500A, TMF induction of TMF, at which the drop tears away from the butt ends of the electrodes, does not much depend on the diameter of the electrodes and is approximately 20 mTl. Current increasing, induction of TMF diminishes. It is true for the height of the drop equal the electrode radius. The height of the drop reducing by one half, the induction is doubled. The calculated information was checked experimentally. THF induction is taken to be minimum if the electrode melting coefficient is increased by 5% as compared to that at hidden arc building-up at no-TMF conditions. The experimental and the calculated data agree very closely for 3 and 4mm diameter electrodes. For 5mm diameter electrodes the experimental data are less than the calculated data. Can it be explained that at melting 5mm diameter electrode the drops are bigger than at melting 3mm diameter electrode, that resulting in more effective induction. The data can be recommended for being used for hidden arc building-up with TMF

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Authors: P.D. Lezhniuk, O.D. Demov, Yu.Yu. Pivniuk

A method of phased installation of compensating units in electrical distribution networks using relative voltage drops as integral indicators was proposed. Introduction of compensating units is one of the most effective ways to reduce electricity losses in distribution networks. In accordance with the existing methods this task is carried out in two ways: maximum reduction of losses and providing acceptable levels of voltage in load nodes. Complicated mathematical methods, nonlinear programming methods in particular, are necessary to solve this problem. Results of the calculations, obtained by these methods, are difficult to be checked on compliance with both criteria, since they characterize different technical parameters. On the other hand, these criteria are of common physical nature which makes it possible to form the integral indicators evaluating both active power losses and voltage drops. The aim of the article is to research and use integral indicators which evaluate both active power losses and voltage drops. A mathematical model of positioning compensating units in electrical network was presented. A calculation example of the phased establishing of compensating units in electrical distribution network by two methods: the one being in use now and the proposed one were presented. Calculation results are given in tabular and graphical forms. These results show the coincidence of the results obtained by these two methods. Proposed method provides minimum active power losses, specified relative voltage drop value and makes it possible to simplify the introduction of compensating units through linearization

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Authors: S.K. Podnebenna

This article describes the features of VAR compensation of variable loads. One of the most common non-symmetric non-linear power consumers are welding power sources. Time and duration of the work of these sources vary randomly. To compensate the consumption of reactive power on the basis of consumption data from the three-phase electricity meters is inefficient. Compensation devices power should be calculated taking into account the asymmetrical consumption/generation of reactive power per phase and changing consumption patterns. Thyristor-controlled reactor, thyristor-switched capacitors, hybrid VAR compensators, active compensators (STATCOMs), «dynamic capacitors» can be used as the VAR compensation devices. Thyristor-controlled reactors can provide smooth regulation of reactive power, but they have high weight and size parameters and are additional sources of higher harmonics. Thyristor-switched capacitors provide stepwise ad-justment of reactive power and are subject to the current higher harmonics. Hybrid VAR compensators make it possible to isolate capacitors from the higher harmonics and ensure smooth regulation, which is achieved by active filter introduction to the reactive power compensation devices based on thyristor-switched capacitors. However, this increases the cost of a compensator and complicates its control system. STATCOMs provide smooth regulation of reactive power, but they are too expensive.Perspective direction in the development of effective VAR compensation devices is «dynamic capacitor». As a result of a feasibility study the prospects for further research of electrical grids power efficiency through the development of effective devices for VAR compensation have been established

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Authors: Z.J. Vorotnikova

Information on the existing methods of non-stationary temporal rows modelling and a method of automatic design of non-stationary temporal rows of technological parameters worked out by the author by SSA method and its further use to analyze the technological process have been presented in the article. The task of researches is to develop such an algorithm that would make it possible to carry out automatic design of non-stationary temporal rows of technological parameters as data from comptrollers arrive and are being stored in CAS server database to be used to analyze the technological process next. The fulfilled analysis of existing methods of non-stationary rows of technological parameters design showed that presently there no theoretical base making it possible to make up such models. The algorithm of automatic modeling and a method of non-stationary temporal rows of technological parameters models storing with the purpose to use them in the imitation and expert systems for further analysis of technological process have been offered. The design method used in the process means additive presentation of temporal rows, where a row can be presented as combination of two sets of different in their nature components. In the article correlation of maximal amount of stationary and non-stationary submodels is presented for 26 parameters (for 180 segments), design quality, and statistical parameters of noise

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Authors: V.М. Zyuz, V.V. Baluhtina

The article deals with the state policy of Ukraine realization in the field of health and life protection, use of the natural environment and providing safe living conditions, recreation, life protection upon the water, accidents prevention, search and rescue of people in distress on the water. The modern concept of safety and water rescuing takes into account the conclusions of the Commission on ecology, natural resources and recreation. Safety upon the water is achieved through correct information of the coastal outline and the natural phenomena around, correct choice of bathing-beaches and equipment, proper visual aids, well organized bathing, systematic explanatory work as to the rules of conduct on the water and precautionary measures, swimming training. Work in the rescuing service demands that the rescuer should be conscious, responsible, willing to help, being able to rescue the drowning. The rescue service task is to protect people from the dangers which they may be subjected to during bathing or swimming. To prevent people losing their life a series of preventive measures should be taken. These include: monitoring on beaches, oral and written instruction to swimmers as to proper behavior on the water, use of proper posters, training of swimmers, lifeguards. The profession of a rescuer on the water is always associated with risk. Therefore, always, before executing their duties, the future rescuers must undergo special training and prove they have the necessary knowledge, skills and qualifications. Otherwise, erroneous actions of a rescuer may lead to injury and death of both the victims of an accident and the members of his team. The reasons for possible accidents on the waters of the Azov sea have been analyzed in the article. Improved methodological basis for the training of lifeguards, including: knowledge of the coastline and beaches, types of sea shores, waves and currents as well as the first aid have been described

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Authors: E.I. Ivanov, E.V. Chuchmai

This article describes the typical algorithms for choosing modern tools made by foreign firms Sandvik Coromant and Walter. The use of modern tools is effective on both new and old equipment. Algorithms ensure orderly operation of engineers in the development of new or upgrading old processes, and may also be useful for students enrolled in the specialty "Mechanical Engineering". The use of modern tools is effective on both new and old equipment. Correctly chosen tool make it possible for you to quickly recoup the cost of new equipment and significantly improve the work of the old equipment. Currently, all cutting tools can be divided into the following groups: a) a solid; b) composite; c) assembly; d) modular (dial-up). In composite cutting tools and parts theholders are attached permanently. For example, the attachment can be blocked by welding or soldering. At modular and modular cutting tools and parts are detachable. In those parts of the modular tool there are separate assembly units (modules) with standardized mounting surface. Thus one and the same cutter head may be attached to a holder (mandrel housings) of different configuration and function. The choice of the cutting part of such tools includes determining the shape and size of the indexable insert (SMP), the geometry of its front surface, corner radius and tool material. Selecting the holder (mandrel body) includes determining its type and size. It is necessary to take into account the possibility of technological equipment (type and size of the mounting surfaces of the tool holder and tool spindle).After selecting the tool it is necessary to determine working regimes

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Authors: O.S. Yandulskyy, G.O. Trunina

The criteria of optimal voltage regulation in the electrical distribution network (EDN) with a source of dispersed generation (SDG) were formulated, if they belong to either one or different owners, taking into account the peculiarities of voltage regulation by means of the SDG and the OLTC system of the transformer. It was found out that under the conditions of economic unprofitability of voltage regulation, in accordance with the above criteria, the owners should take up coordinated work – the general objective function of voltage regulation to improve the effectiveness of regulation and achieve cost-effectiveness. The criteria of optimal voltage regulation if EDN and SDG belong to one owner were formulated. If their work becomes coordinated it is necessary to know exactly which transformer must be regulated; so a transformer with OLTC system should be chosen. Selection sequence is based on the calculation of the sensitivity of the voltage at the nodes within SDG with respect to OLTC position. The proposed OLTC system and SDG coordinated work makes it possible to increase the effectiveness of voltage regulation in the EDN with SDG under different conditions of ownership and increase the economic profitability of regulation

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Authors: V.L. Bakulevsky

A model for the calculation of technical losses of electricity in the air lines with voltage of 6-35 kV based on neural networks with due regard to meteorological factors has been worked out; the main components of the model have been considered and researched; the best ones being selected, that is: a set of input variables, volume of excerpts (training, control and testing), architecture and net-work activation function, network learning algorithm was proposed. Simulation was conducted in OS STATISTICA Neural Networks. Input variables are: transmission line (TL) active load, transmission line rated voltage, transmission line cross section and length of wire, average air temperature, wind speed, rainfall availability; output variable – that is technical losses in electric transmission line. To select the optimal input vector model the data selection methods were used: variables testing using trial and error method, variables stepped inclusion and exclusion algorithm. It has been proved that the most important variables are TL active load and average air temperature. all input variables under review should be included in the created artificial neural network (ANN). It was determined that the optimal volume for ANN training set given parameters made 250 observations, control and test excerpts volume were respectively 250 and 332 observations. It has been proved that the best type of architecture is multilayer perceptron ANN that being compared to radial basis functions and generalized regression network is characterized by minimal errors and complexity of the network. ANN of the following architecture: multilayer perceptron, 7 neurons in the input layer, 5 neurons in the hidden layer, 1 output neuron, logistics as activation function – has been taken optimal

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Authors: Yu.P. Goncharov, E.I. Sokol, V.V. Zamaruev, V.V. Ivakhno, S.Yu. Krivosheev, О.V. Eres'ko, E.A. Malyarenko, B.О. Styslo, М.V. Panasenko, V.G. Sychenko, E.М. Kosarev

The arising deficiency of traditional energy sources necessitates the use of renewa-ble energetics. One of the advantages of the sources of renewable energy is the possibility of constructing a system of distributed generation. For conditions of Ukraine distributed generators placed along the existing facilities with a linear arrangement are the most promising. The railways with their land dispossession belt can be used for these purposes. The distributed generation systems in railway transport can also be used in the regions with an unstable electricity supply, improving power quality, feeding autonomous objects of railway infrastructure. Distributed generation equipment can be used to reduce bias and voltage unbalance in power systems of stationary consumers. The projects using solar energy for the needs of railway transport show their high adaptability and efficiency. The article is devoted to the development of the DC power supply system. The railway contains additional longitudinal DC line with an operating voltage of about 1 kV and a system of semiconductor converters for connecting the longitudinal line and the main contact system through matching modules. Sequential positioning of the longitudinal line and the photo module is consistent with their properties as a current source that is proportional to the intensity of solar radiation. Semiconductor converters should be made using the same "a forward" topology, which simplifies the electrical circuit. Amorphous magnetic alloy is the most promising material for the existing isolation transformers in the system. Proper value of the operating frequency of the AC intermediaries is about 1 kHz. Traction power supply system with distributed PV generation, discussed in this article, will make it possible to put into practice the concept of intellectual traction power supply, optimizing the process of electric energy consumption in the traction net-work

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Authors: V.A. Demchenko

Experimental and theoretical studies of the wheel surface outline influence on the horizontal and cross forces interacting between the elements of the track and the rolling stock, operating on the Ukrainian railways, have been carried out. The theory modelling the rolling stock wheel pair impact on the stability of the wheel pairs motion in contact with the track has been further developed. Experimental study of the locomotive wheel pairs rolling surface has been carried out. Analyzing the experimental studies we have found out that the wheel pairs with reinforced surface, have a greater resistance to wear and tear but just to a certain extent, and then the rolling surface geometric dimensions wear and tear rate increases sharply. The digital outline obtained by means of laser scanning was used to calculate transverse horizontal forces. The calculations were made for three types of wheel pairs wear at the speeds up to 160 km/h, the track curves radii varying from 300 m to 1000 m. The two types of rails- R65 and UIC-60 both new and worn were used. Analyzing the results of the calculations it can be concluded that the rolling surface state influences the horizontal lateral force, wheel pair vibration amplitude; the critical speed of the locomotive reduces. Thus, to know the critical speed which must be higher for any wear of the rolling speed of locomotive wheel pairs is very impor-tant as it ensures the decrease of the track side effects. The theoretical results make it possible to estimate track and rolling stock interaction force; it can be concluded that the locomotive wheel pairs suspension rigidity influences the cross force too