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Date submitted2022-05-12
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Date accepted2022-09-15
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Date published2022-12-29
Problem solution analysis on finding the velocity distribution for laminar flow of a non-linear viscous flushing fluid in the annular space of a well
- Authors:
- Vasiliy I. Nikitin
Modern drilling fluids are non-linear viscous media with an initial shear stress. In classical scientific works on hydromechanical modeling of drilling fluids motion in pipes and annular channels the Shvedov – Bingham approximation and Ostwald – de Waale power-law model were used, which did not fully account for behavior of technological fluids in a wide range of shear rates. This article presents a numerical solution for a mathematical model of drilling fluid motion of the three-parameter Herschel – Bulkley rheological model in the annular space of the well. The Herschel – Bulkley model in the rheological equation takes into account the presence of initial shear stress and a tendency for viscosity to change with shear rate, which distinguishes it from the Ostwald – de Waale and Shvedov – Bingham models. The target function in solving the equation of motion is the velocity distribution in the radial direction of the upward flow of the flushing fluid. The analysis of obtained solution is based on the theory of velocity profile influence on quality of cuttings removal during wellbore cleaning. Due to peculiarities of mathematical statement of the task, which supposes necessity of differential equation of motion solution, Wolfram Mathematica computational software has been used as a calculation tool. The analysis of numerical solution allowed to draw conclusions about the possibility of its application in evaluation of velocity profile when drilling fluid moves in annular space of the well. The possibility for application of modified excess coefficient as a relative quantitative parameter for evaluation of velocity profile uniformity was substantiated.
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Date submitted2022-03-24
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Date accepted2022-07-21
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Date published2022-12-29
A probabilistic study on hole cleaning optimization
- Authors:
- Seyyed Shahab Tabatabaee Moradi
Hole cleaning is considered as one of the most important drilling fluid functions. An efficient hole cleaning ensures a reliable well drilling practice with minimum troublesome problems. In this study, two main steps of hole cleaning, i.e., cuttings removal from under the bit and cuttings transport to the surface are discussed based on the drilling data of a shale formation. The traditional models for optimization of each step are presented. As the models require variety of input data, which are usually subjected to some extent of errors and uncertainties, the output of the model is also an uncertain parameter. Using Monte Carlo simulation, a simple probabilistic study was conducted to quantify the certainty level of the obtained results. Based on the result of this study, it is shown that for the proposed well, a good hole cleaning is expected. However, a more reliable decision for further hole cleaning optimization should be made considering the results of uncertainty analysis.
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Date submitted2021-12-19
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Date accepted2022-07-21
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Date published2022-11-10
Increasing the content of coarse fractions in the mined coal mass by a combine using paired cuts
The main volume of coal is mined underground using shearers. In modern shearers, auger actuators are mainly used, which are distinguished by the simplicity of design, manufacturability and reliability. However, in the process of separating coal from mass by cutting, the yield of fine grades is 40-50 % of the total production volume. Therefore, the search and development of technical solutions that provide an increase in the yield of large fractions in the process of coal mining with auger shearers is an urgent task. Traditionally, this problem is solved by increasing the thickness of the slices, which is achieved by installing cutters with a larger radial reach and increasing the shearer feed rate. An unconventional way to increase the cross section of slices by forming energy-efficient paired and group slices with mutual superposition of stress fields in the mass from the action of neighboring cutters is considered. The results of modeling the process of cutting coal confirm that an increase in the efficiency of destruction of the rock mass by the cutters of the auger executive bodies of the shearer can be achieved by a complex technical solution, including the formation of paired cuts and combined stress zones in the rock mass. As a result, the output of large fragments when cutting with paired cutters increases by 1.3-1.8 times compared with cutting with a single cutter.
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Date submitted2021-10-15
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Date accepted2022-09-06
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Date published2022-11-10
Experimental research on the thermal method of drilling by melting the well in ice mass with simultaneous controlled expansion of its diameter
- Authors:
- Danil V. Serbin
- Andrey N. Dmitriev
During the seasonal work of the 64th Russian Antarctic Expedition in 2018-2019 at the “Vostok” drilling facility named after B.B.Kudryashov (“Vostok” station, Antarctic) specialists of Saint Petersburg Mining University conducted experimental investigations on the process of drilling by melting with simultaneous expansion of wells in the ice mass. A test bench and a full-scale model of a thermohydraulic reamer-drilling tool were developed, manufactured and tested for the research. The first bench tests of the full-scale model proved its efficiency and suitability for experimental drilling with simultaneous expansion of wells in ice mass; its operational capabilities were determined and the drawbacks that will be taken into account in future were found out. The article substantiates the choice of constructive elements for thermohydraulic reamer-drilling tool. It is determined that the technology of full diameter drilling with simultaneous expansion of the well in ice mass can be implemented by combining contact drilling by melting and convective expansion with creation of forced near-bottomhole annular circulation of the heated heat carrier. Dependencies of expansion rate on main technological parameters were determined: active heat power of heating elements in penetrator and circulation system, mechanical drilling rate, pump flow rate. According to the results of investigations, the experimental model of thermohydraulic reamer-drilling tool will be designed and manufactured for testing in conditions of well 5G.
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Date submitted2020-05-13
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Date accepted2021-05-21
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Date published2021-09-20
Increasing the efficiency of technological preparation for the production of the manufacture components equipment for the mineral resource complex
An increase of components production for the equipment intended for oil and gas production is a key factor for analyzing existing technological processes and searching for new technological solutions to improve the efficiency of the production process and the quality of components. The article presents a simulation model designed to determine the rational technological processing parameters for the production of the “Centralizer shell” part. The basis for optimizing the working cycle of a production line is synchronization based on the principle of proportionality, which involves equalizing the duration of all technological operations with the rhythm of the production line. Synchronization of technological operations on the production line is carried out by choosing rational cutting parameters for each technological transition (cutting speed, feedrate, number of working passes). The “Centralizer shell” part is made of titanium alloy VT16, which has high strength, corrosion resistance and ductility. For the part under consideration, the permissible values of the cutting parameters were determined based on the calculation of the total processing error, as well as the frequency of replacement of the worn cutting tool. The simulation model described in the article made it possible to increase the efficiency of the production process due to the synchronization of technological operations and the search for rational technological parameters, as well as to improve the manufacturing quality of the “Centralizer shell” part by analyzing the processing error at various parameters of the technological process.
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Date submitted2020-07-04
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Date accepted2021-03-29
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Date published2021-09-20
Transition between relieved and unrelieved modes when cutting rocks with conical picks
In the modern theory of rock cutting in production conditions, it is customary to distinguish two large classes of achievable cutting modes – relieved and unrelieved. The kinematics of rock-breaking machines in most cases determines the operation of the cutting tool in both modes in one cycle of the cutting tool. The currently available calculation methods have been developed for a stable, usually unrelieved cutting mode. In this article, the task is set to determine the conditions for the transition between cutting modes and the modernization of the calculation method for determining the forces on the cutting tool. The problem is solved by applying methods of algebraic analysis based on the search for the extremum of the force function on the cutter, depending on the ratio of the real cut spacing to the optimal spacing for the current chip thickness. As a result of solving the problem, an expression is obtained for determining the chip thickness, for which, at the specified parameters, the transition between the relieved and unrelieved cutting modes is provided. The obtained result made it possible to improve the method of calculating the forces on the cutting tool in the areas of the cutter movement with relieved cutting.
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Date submitted2019-11-04
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Date accepted2020-01-12
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Date published2020-10-08
PDC cutter pressure on plastic-brittle rock in the process of its destruction
- Authors:
- Oleg B. Trushkin
- Hamzja I. Akchurin
Presently, there are no methods for calculating the parameters of the drilling practices with rock-cutting tools equipped with polycrystalline diamond composite (PDC cutters). To create such a method requires the studying their work. The article presents the results of bench studies of the PDC cutters in the process of a rock sample breakdown when reproducing the actual layout of the cutters on the working surface of the bit. An important parameter of PDC cutters operation, which is necessary for the bit load analysis, is the pressure of the cutters on the rock during its breakdown. The total pressure of a cutter on the rock can be broken into two mutually perpendicular components: the forcing pressure and the cutting pressure. It is proposed to evaluate the PDC cutters loading at breakage of rocks of different hardness using relative values of forcing and cutting pressures, which are calculated relative to the yield strength of the rock by the die. It is established that the variability of the average relative pressures of forcing and cutting is significantly influenced by drifting per bit turnover and the radius of the cutter on the bit. The dependences of the maximum relative pressures of PDC cutters at the plastic-brittle rock breakdown on the drifting per bit turnover and the radius of the cutter location on the bit are obtained. It has been established that when drifting up to 0.4 mm per turn, the main mechanism of breakdown is cutting, and with the increase of the breakdown depth, the process of forcing becomes decisive.
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Date submitted2019-06-28
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Date accepted2019-09-03
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Date published2019-12-24
Development of a drilling process control technique based on a comprehensive analysis of the criteria
- Authors:
- V. V. Neskoromnykh
- M. S. Popova
Compliance with drilling operations requirements is achieved by introducing advanced approaches to the management of the drilling process. Main requirement is to reduce the time and material costs for construction of the well. Increase in drilling speed is provided by rational selection of rock cutting tools and modes of its use. Development of a new generation of rock cutting tools is a complex process and requires systematic, integrated approach. In order for high costs of developing and manufacturing the tool to pay off without significantly increasing the cost of drilling, considerable attention should be paid to scientifically justified methods for its running. At well drilling using bottomhole telemetry systems with full computer support for the drilling process, there is a reasonable possibility of using a control technique based on objective results of the drilling process coming directly from the bottomhole of the well in real time. Use of a full factorial experiment is justified for processing data that affect drilling performance. Aim of the research is to develop a drilling process management technique based on a comprehensive analysis of criteria online. Objects of research: rock destruction mechanism during drilling; parameters affecting the process of well drilling; optimization of well drilling processes. The research used the following: experimental drilling with a diamond tool at the bench, method of a full factorial experiment, analytical studies. Article highlights the factors affecting the performance of a diamond rock cutting tool in the process of drilling a well, notes main criteria affecting the efficiency of the drilling process. It also describes mechanism of volumetric destruction, defines the conditions for the destruction of rock at various drilling modes and the dependence of the change in deepening per round on the parameters of the drilling modes. Technique of controlling the parameters of the drilling mode is considered, which allows determining indirectly the mode of rock destruction at the bottomhole of the well and choosing optimal values of the parameters for the drilling mode that correspond to the most favorable conditions.
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Date submitted2019-07-23
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Date accepted2019-09-19
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Date published2019-12-24
Estimation of abrasiveness impact on the parameters of rock-cutting equipment
Development of equipment, which provides access to underground mineral deposits and their extraction, requires the use of all the accumulated experience and advanced scientific research in the area of mechanical rock cutting. The most important issues of using mechanical rock cutting tools are their wearability and consumption, which have an impact on technical and economic indicators of project efficiency. The paper describes Russian and foreign practices of estimating tool wear resistance, expressions to determine critical cutting speed, methods to evaluate tool consumption. It is demonstrated that wearability of mechanical tools and associated effects are to a large extent defined by rock abrasiveness. It is highlighted that in Russia the index is calculated using Baron-Kuznetsov method, which is briefly described in the paper. In many countries with a highly-developed mining industry, rock abrasiveness is estimated with a Cerchar Abrasiveness Index (CAI), recommended by the International Society for Rock Mechanics. Its description is also presented in the paper.
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Date submitted2019-07-06
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Date accepted2019-08-25
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Date published2019-12-24
Improving the efficiency of technological preparation of single and small batch production based on simulation modeling
Technological preparation of production is an integral stage of the production process, which is characterized by high complexity, which is largely felt in the conditions of single and small-scale types of production. The effectiveness of technological preparation of production is increased through automation with the use of simulation modeling. The objective of the study is to develop a simulation model that allows you to determine a rational version of the process for processing a batch of parts. The simulation model described in the article allows to analyze the production schedule of the enterprise, build processing routes, evaluate options for using various types of workpieces and technological equipment, determine the acceptable values of cutting conditions, and choose a rational variant of the technological process of processing a batch of parts. The developed simulation model is based on the principles of modular technologies, the part is considered as a combination of individual elementary surfaces. Each elementary surface contains information about the technological processing route, technological equipment and the type of technological equipment used in its manufacture, cutting conditions and the size of the allowance for each processing stage. The rational choice of the technological process is selected on the basis of multicriteria analysis according to three criteria: the value of variable costs, the production time of a batch of parts and the value of the processing error. The analysis of these criteria is made and the parameters that have the greatest impact on their value are determined. The developed classification of surface elements is described: design elements, technological elements, basic elements, as well as a mathematical model based on which the calculation of the values of the criteria for choosing a rational option.
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Date submitted2018-11-05
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Date accepted2019-01-01
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Date published2019-04-23
Features of elementary burst formation during cutting coals and isotropic materials with reference cutting tool of mining machines
- Authors:
- V. V. Gabov
- D. A. Zadkov
- Khac Linh Nguyen
The paper considers the cutting of brittle coals and rocks by a single cutter of a mining machine, in contrast to the generally accepted integral approach, different from the standpoint of the formation of successive elementary bursts that make up the cut. The process of the formation of an elementary bust in time is viewed as successive phases. Due to the complexity and multi-factor nature of the process, preference is given to experimental bench studies using reference cutters, isotropic materials, and real rock blocks. The bursting parameters values greatly influence the time of static forces action, the peculiarities of the formation of stress fields in the undercutter zone of the rock mass and the conditions for the emergence and development of main cracks in the near-cut zones during the cutting process. The accepted phase-energy method of analyzing the process, which most closely matches the structure of the studied process, revealed a more significant, than previously expected, effect on the cutting process, variability of cutting speed and potential energy reserve in the cutter drive. The paper discusses the possibility of purposeful formation of the parameters of elementary bursts. It describes new ways to improve the efficiency of cutting coal and rocks, in particular, reducing the maximum loads and specific energy consumption. It also considers the possibility of reducing the grinding of the rock mass and dust formation.
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Date submitted2018-09-08
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Date accepted2018-10-27
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Date published2019-02-22
Special strategy of treatment of difficulty-profile conical screw surfaces of single-screw compressors working bodies
- Authors:
- A. S. Vasilev
- A. A. Goncharov
The article deals with the problems arising during the shaping of complex profile tapered helical surfaces. These surfaces form the geometry of the working bodies of single-screw miniature compressors, which have great prospects for use in mobile miniature compressor plants, which is especially important for medical and space technology, robotics, oil and gas and mining industries. Due to the fact that the capabilities of existing CAD systems do not allow obtaining three-dimensional models of these surfaces, the problem of preparing a control program for a CNC machine arises, since the calculation of the tool path in CAM systems when processing complex surfaces is impossible without a three-dimensional surface model. To solve the problem, an automated programming system was developed that implements a formalized toolpath calculation in accordance with the proposed special processing strategy for conical helical surfaces. As the initial data for calculating the toolpath, the system needs information about the tool geometry and the helical surface in a parametric form, which makes it possible to abandon the construction of a three-dimensional surface model. The results of processing prototypes for the proposed strategy are given.
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Date submitted2018-07-21
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Date accepted2018-09-03
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Date published2018-12-21
Possibilities of open eruption elimination by drilling tools
- Authors:
- P. Bujok
- M. Klempa
- M. Jakubcik
- J. Ryba
- M. Porzer
The most important raw materials for different industries are oil and natural gas. With increasing consumption, the demand for drilling and the quality of production increases. Therefore, the exploration and production of hydrocarbons requires not only first-class machinery and technological equipment, but also qualified personnel. Exploration and drilling, production of hydrocarbons, like any other industry, cannot avoid accidents, emergencies and catastrophes. The worst type of well accident is undoubtedly an open eruption of the extracted crude oil. Open eruption can lead to serious injuries to the rig personnel, damage and destruction of equipment, negative environmental impact and loss of crude oil. Exploratory drilling can cause the rise of pressure and its subsequent manifestations. During the first deep drilling, there may not be enough information about the drilled horizons. If the reservoir pressure in the production horizon is higher than the hydrostatic pressure of the fluid in the well (for example, drilling mud), the formation fluids flow into the well and move towards the surface, which causes open eruption. The rig personnel must be properly trained to be able to recognize the occurrence of rising pressure by various signs and to respond effectively to the situation. Sometimes, under the influence of the human factor or equipment failure, open eruption still occurs. The article discusses the possibilities of eliminating open eruptions with drilling tools.
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Date submitted2018-05-04
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Date accepted2018-07-23
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Date published2018-10-24
Analysis of possible enhancementof properties of VK15 material used for drilling tools
- Authors:
- Yu. A. Kurganova
- K. S. Panina
- P. S. Beshenkov
Traditionally, when drilling hard and abrasive rocks, it is recommended to use a tungsten-cobalt hard alloy VK15. The analysis of information on the possibility of improving the potential of the material has demonstrated the existence of mechanisms that provide structural transformations that enhance its strength, hardness and toughness. The use of such technology instead of traditional methods will lead to an increase in the operating efficiency and durability of the tool. During the work, experimental samples of alloy VK15 were obtained by sintering in four different modes. Then their properties were analyzed. The results of the metallographic study carried out on the «Carl Zeiss» microscope made it possible to estimate the distribution of tungsten carbide grains in cobalt bon and show the grinding of the carbide phase. Thus, with traditional sintering, the amount of tungsten carbide grains with an average size of less than 1 μm in diameter from the entire size range reaches 19.5 %, while after additional heat treatment with a holding time of 1280 °C, the value was 41.5 %; 900 °C – 59.1 %; 600 °С – 54.5 %. The maximum improvement results were the following: hardness by 18 %, a coercive force by 49 %, and crack resistance by 11 % of the traditional alloy, there were achieved at 900-1280 °C. A hypothesis has been put forward on the formation of additional structural elements not detected by the methods of optical metallography. Studies of the topology and structure of the samples on an atomic force microscope confirmed the presence of nanoscale inclusions from 20 to 40 nm (presumably tungsten carbide) in a cobalt bond.For VK15, comparative studies of properties and analysis of the microstructure of experimental samples obtained by the traditional sintering and modified technology have shown that the sintering mode at 900 °C is a priority.
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Date submitted2017-10-25
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Date accepted2018-01-17
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Date published2018-04-24
Innovative technology of large-size products manufacture
- Authors:
- S. N. Sanin
- N. A. Pelipenko
Advantages and prospects for the use of mobile robotic machine-tools in the manufacture of large parts in the mining, cement and nuclear industries are considered, as well as the importance of using welded structures to reduce production costs. Schemes for finishing mechanical machining of welded large-sized parts such as bodies of revolution with the use of mobile robotic machine-tools equipped with a belt-grinding tool, an enlarged description of the technological process for manufacturing a large-sized shell of a welded structure are presented. The conclusion is made that it is necessary to take into consideration the use in the industry of frameless production technology, especially for the machining of large-sized parts, and the use of small mobile robotic machine-tools is a productive approach and has a prospective character. The technological approaches proposed in the article make it possible to remove the restriction on the overall size and mass of the parts being manufactured, which are proposed to be manufactured directly at the site of future operation. The effectiveness of this technology is confirmed both by theoretical research and by practical data of the authors. It was noted that the production by the domestic machine-tool industry of mobile universal and special robotic machine-tools will allow the country's engineering industry to be brought to a new, high-quality world level.
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Date submitted2014-12-11
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Date accepted2015-02-11
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Date published2015-12-25
Influence of the type of hardening treatment on wear-resistant materials of mining equipment
- Authors:
- V. I. Bolobov
- S. A. Chupin
For example, steel 110G13L as the material of teeth of excavator buckets, shows that the work hardening (hardening) is an effective means to increase (up to 10 times) the wear resistance of components in contact with abrasive media, such as marble, yielding the steel in a state of hard-ening of hardness. In the case of wear on the rocks (granite, gabbro) with a hardness greater than the hardness of steel, the effect of hardening has almost no effect. It was found that high-temperature thermomechanical treatment of steel 35HGSA as the material of holders of rotary cut-ters (strain at 900 С, water quenching, tempering at 230 С) leads to a substantial increase of its hardness (23 %) and durability (38 %) compared to typical heat treatment used in the manufacture of cutting tools at the factory.
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Date submitted2014-10-09
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Date accepted2014-12-26
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Date published2015-08-25
Improving the precision of manufacturing power hydraulic cylinders of powered roof supports based on a vibration-damping tooling system
- Authors:
- V. V. Maksarov
- Yu. Olt
The article deals with a new system of a vibration-damping tool, the effect of which is achieved by a combination of the multi-layer principle and the use of anisotropic properties of sheet metal. Operation of such tool systems in turning operations can reduce high-frequency vibra-tions arising in the process of cutting due to the ordered disorientation of anisotropic plate texture of a multilayer modular tool holder that allows you to efficiently dissipate oscillatory wave energy at the boundary of transition between the plates of the tool holder. This method allows increasing the resistance of the tool cutting edge significantly and expanding the technological capabilities for the effective selection of cutting modes to ensure compliance with requirements for dimensional and geometric accuracy, quality of processed surfaces of powered roof supports, hydraulic units, mining machinery and equipment.
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Date submitted2009-08-08
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Date accepted2009-10-26
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Date published2010-02-01
Relationship between wear resistance of cutting bit body of mining tool and distribution of hardness along the cutting bit
- Authors:
- M. P. Talerov
In present article the courses of low wear resistance of rotary cutting bit body and also the courses of one-sided wear are described. The results of hardness of the cutting bit body from various manufacturers are represented here. In summary a conclusion was made that the utilization of thermal treatment after pressing removes specific structure that can be the course of one-sided wear genesis.
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Date submitted2008-11-19
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Date accepted2009-01-04
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Date published2009-12-11
Complex modernisation of manufacture on Open Society «Severstal»
- Authors:
- V. M. Vasiltsova
- O. A. Popova
- S. N. Vinogradov
The metallurgical complex is a part of the manufactures making a basis of industrial and defensive potential of Russia. For increase in volume and production improvement of quality are defined internal possibilities of manufacture on the basis of its modernisation. Attempt of actualisation of the term «modernisation» at the expense of the complex approach to its treatment and workings out of the mechanism of acceptance of corresponding organizational and administrative decisions is undertaken. The technique is specified and the estimation of a technical condition of the equipment is carried out, the technical and economic analysis of modernisation on Open Society «Severstal» is carried out. Ways of perfection of a control system by updating of industrial potential of the metallurgical enterprise taking into account the requirement of the complex approach are defined.