ENSURING THE QUALITY OF MANUFACTURING GEAR TRANSMISSIONS IN POWER MECHANICAL ENGINEERING

2019 ◽  
pp. 155-166
Author(s):  
O. Yakimov ◽  
S. Uminsky ◽  
N. Klimenko ◽  
L. Bovnegra ◽  
Yu. Shikhireva
Keyword(s):  
Surface Layer ◽  
Residual Stresses ◽  
Power Plants ◽  
Operating Conditions ◽  
Engineering Industry ◽  
Power Engineering ◽  
Important Place ◽  
Continuous Increase ◽  
Gear Grinding

The development of modern power engineering goes along the line of continuous increase of speeds, efficiency and power units. Gears and gearboxes are crucial parts of modern mechanisms and occupy an important place in the domestic power engineering industry. The strength and durability of gears, in addition to design factors, to a large extent depends on the processing techniques. The final stage of manufacturing such wheels is the gear grinding operation. In the process of tooth-grinding, complex and unique thermomechanical processes take place in the thin surface layer. As a result of short-term heating to high temperatures, structural transformations, called prizhogami, occur in such a surface layer, and in some cases even micro and macro-cracks. In addition, there are cases of manufacturing gears with hidden grinding defects (for example, the appearance in the surface layer of teeth of large tensile stresses), which reduces the service life, and in some cases causes the teeth to break under operating conditions. The development of effective measures to ensure the quality of the surface layer during a gear grinding operation largely depends on the ability to predict (or calculate) temperatures and residual stresses along the depth of the cemented tooth layer. A method for calculating the internal residual stresses arising during gear grinding of wheels from cemented steels is proposed. On the basis of the performed calculations and experiments, the ways of improving the quality of manufacturing the working surfaces of gears used in units of thermal and nuclear power plants are proposed and substantiated.

scholarly journals IMPROVING GRINDING OF GEAR WHEELS APPLIED IN GEARBOXES OF POWER ENGINEERING

2021 ◽  
pp. 45-56
Author(s):  
Oleksiy Yakimov ◽  
Natalia Klimenko ◽  
Kateryna Kirkopulo ◽  
Andrey Pavlyshko ◽  
Sergyi Uminsky ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Operating Conditions ◽  
Power Engineering ◽  
Important Place ◽  
Continuous Increase ◽  
Method Of Calculation ◽  
Gear Grinding ◽  
Thermomechanical Processes

Development of modem power engineering follows the line of continuous increase in speed, coefficient of corrosive action and capacity of units. Gears and reducers are responsible parts of modem machinery and occupy an important place in the domestic power engineering construction. Durability and wear resistance of gears, apart from the design factors, also depends on the technological methods of treatment. The final stage of production of such wheels is the operation of gear grinding. In the process of gear grinding in a thin surface ball there are complex thermomechanical processes. As a result of short-time heating to high temperatures, structural transformations, burns, and in some cases even micro- and macro-thicknesses occur in such a surface bail. In addition, there are cases of making tooth wheels with adjacent defects grinding (for example, the appearance of the surface of the ball teeth of large tensioning forces), which reduces the life of the work, and in some cases causes a breakdown of the teeth in operating conditions. Development of effective measures to ensure the quality of the surface of the ball on the operation of grinding baggage in part depends on the possibility of predicting (or calculation) of temperatures and residual loads on the depth of the cemented teeth ball. The method of calculation of internal surplus Toads occurring during grinding of wheels with cemented steels is suggested. On the basis of the performed calculations and experiments the ways to improve the quality of production of working surfaces of gears, which are used in the wits of thermal and nuclear power plants are suggested and grounded.

scholarly journals Rated definition of degree of cutter coating influence upon parameters of surface layer quality of parts worked

2017 ◽  
Vol 2 (7) ◽  
pp. 20-24
Author(s):  
Вячеслав Безъязычный ◽  
Vyacheslav Bezyazychnyy ◽  
Максим Басков ◽  
Maksim Baskov
Keyword(s):  
Surface Roughness ◽  
Surface Layer ◽  
Residual Stresses ◽  
Layer Surface ◽  
Wear Resistant Coatings ◽  
Cutter Wear ◽  
Definition Of ◽  
Surface Layer Quality ◽  
The Impact

The impact of cutter wear-resistant coatings upon cutting process parameters and characteristics of surface layer quality in the parts worked: residual stresses, a degree and a depth of work hardening of a surface layer, surface roughness is investigated.

Turbo Gas Power Plants Performance Evaluation for Putting Into Commercial Operation

2009 ◽  
Author(s):  
Erik Rosado Tamariz ◽  
Norberto Pe´rez Rodri´guez ◽  
Rafael Garci´a Illescas
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Performance Test ◽  
Operating Conditions ◽  
Technical Requirements ◽  
Requirements Specifications ◽  
Commercial Operation ◽  
International Regulations ◽  
Operational Tests

In order to evaluate the performance of new turbo gas power plants for putting in commercial operation, it was necessary to supervise, test and, if so the case, to approve the works of commissioning, operational and acceptance of all equipments and systems that constitute the power plant. All this was done with the aim of guaranteeing the satisfactory operation of these elements to accomplish the function for which they were developed. These activities were conducted at the request of the customer to confirm and observe that the evidence of the tests was carried out according to the specifications and international regulations. The putting into commercial operation activities were done in collaboration with the supplier and manufacturer of equipment, the client and the institution responsible for certification and approval of the plant. All this in a logical and chronological order for the sequence of commissioning tests, operation and acceptance. Commissioning tests were carried out on-site at normal operating conditions, according to the design and operation needs of each power plant of a group of 14. Once the commissioning tests were completely executed and in a satisfactory manner, operational tests of the plants were developed. This was done by considering that they must operate reliable, stable, safe and automatically, satisfying at least, one hundred hours of continuous operation at full load. After evaluating the operational capacity of the machine, it was necessary to determinate the quality of the plant by carrying out a performance test. Finally, it was verified if every unit fulfills the technical requirements established in terms of heat capacity of the machine, noise levels and emissions. As a result of this process, it is guaranteed to the customer that the turbo gas power plants, their systems and equipments, satisfy the requirements, specifications and conditions in agreement with the supplier and manufacturers referring to the putting into commercial operation of the plant.

scholarly journals Selected Properties of the Surface Layer of C45 Steel Parts Subjected to Laser Cutting and Ball Burnishing

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3429 ◽  
Author(s):  
Agnieszka Skoczylas ◽  
Kazimierz Zaleski
Keyword(s):  
Surface Layer ◽  
Residual Stresses ◽  
Laser Cutting ◽  
Experimental Studies ◽  
Hardened Layer ◽  
Ball Burnishing ◽  
Absolute Value ◽  
The Impact ◽  
Compressive Residual Stresses

In this article, we report the results of experimental studies on the impact of ball burnishing parameters on the roughness, microstructure and microhardness of the surface layer of laser-cut C45 steel parts. We also analysed the distribution of residual stresses generated in the surface layer of these parts. Laser-cut parts often require finishing to improve the quality of their surface. The tests performed in this study were aimed at assessing whether ball burnishing could be used as a finishing operation for parts of this type. Ball burnishing tests were performed on an FV-580a vertical machining centre using a mechanically controlled burnishing tool. The following parameters were varied during the ball burnishing tests: burnishing force Fn, path interval fw and the diameter of the burnishing ball dn. Ball burnishing of laser-cut C45 steel parts reduced the surface roughness parameters Sa and Sz by up to 60% in relation to the values obtained after laser cutting. Finish machining also led to the reorganization of the geometric structure of the surface, resulting in an increase in the absolute value of skewness Ssk. This was accompanied by an increment in microhardness (maximum microhardness increment was ΔHV = 95 HV0.05, and the thickness of the hardened layer was gh = 40 µm) and formation of compressive residual stresses in the surface layer.

scholarly journals Changes of Insulation Properties of Photovoltaic Cables Caused by Ageing Treatment

2020 ◽  
Vol 6 (1) ◽  
pp. 6-9 ◽  
Author(s):  
Juraj Packa ◽  
Vladimir Kujan ◽  
Daniel Štrkula ◽  
Vladimír Šály ◽  
Milan Perný
Keyword(s):  
Power Plants ◽  
Real Life ◽  
Life Time ◽  
Operating Conditions ◽  
Solar Panels ◽  
Font Size ◽  
Long Term Stability ◽  
Cable Systems

<span style="font-family: 'Times New Roman',serif; font-size: 10pt; mso-fareast-font-family: 'Times New Roman'; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: AR-SA;" lang="EN-US">An important part of the photovoltaic power plants are cable systems. The dielectric properties of cables, reliability and durability depend on quality of production processes, operating conditions and degradation factors, as well. Expected lifetime of cable systems is more than 20-30 years in general. Their failure free operation and long-term stability of properties has a direct impact on the economic return of the investments. According to our experiences the tests in compliance with valid standards are not adequate to verify real life time during operation. Photovoltaic cables intended for use in outdoor applications for the connection between the solar panels and possible connection between panels and inverter were chosen for our experiments. <span style="-ms-layout-grid-mode: line;">The changes </span>of insulation resistance and breakdown voltage caused by some degradation factors, mainly water, are presented. This research was inspired by real failure in operation.</span>

scholarly journals Surface layer quality in compressor titanium blades at multiaxes deep grinding

2017 ◽  
Vol 2 (12) ◽  
pp. 15-19
Author(s):  
В. Полетаев ◽  
V. Poletaev ◽  
Е. Цветков ◽  
E. Tsvetko
Keyword(s):  
Titanium Alloy ◽  
Surface Layer ◽  
Residual Stresses ◽  
Gas Turbine ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Blade Surface ◽  
A Value ◽  
Surface Layer Quality

The investigation results of technological conditions impact at multiaxes deep grinding upon quality of titanium alloy blade surface layer in the compressors of gas turbine engines (GTE) are presented. The grinding mode impact upon a surface and a value of residual stresses in a surface layer of blades is defined and also conditions for defect occurrence as burns on blade surfaces under machining are detected.

Restoration of Agricultural Machines Surfaces by White Cast Iron with the Formation of Technological Repair Units

2018 ◽  
Vol 927 ◽  
pp. 43-47
Author(s):  
V.K. Afanasyev ◽  
A.P. Chernysh ◽  
S.V. Dolgova
Keyword(s):  
Surface Layer ◽  
Cast Iron ◽  
White Cast Iron ◽  
Low Cost ◽  
Operating Conditions ◽  
Technological Environment ◽  
New Approach ◽  
Selection Of ◽  
Agricultural Machines

This article develops a fundamentally new approach in the selection of optimal methods for restoring of worn surfaces of agricultural machines’ tools with the formation and application of technological repair units. Based on the systematization and linkage of modular worn-out surfaces, their operating conditions, technological environment and the choice of their optimal combinations, it found a low-cost method of restoring details with white cast iron to gain a necessary quality of a new surface layer.

scholarly journals Belarus Power Engineering System Modeling Taking into Account the Nuclear Power Plant Commissioning

2021 ◽  
Vol 64 (1) ◽  
pp. 5-14
Author(s):  
A. A. Mikhalevic ◽  
U. A. Rak
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Energy Systems ◽  
Operating Conditions ◽  
Power Engineering ◽  
Power Balance ◽  
Engineering System ◽  
Large Share ◽  
Load Duration

The article presents the analysis of the specific features of modeling the operation of energy systems with a large share of nuclear power plants (NPP). The study of operating conditions and characteristics of different power units showed that a power engineering system with a large share of NPP and CHPP requires more detailed modeling of operating modes of generating equipment. Besides, with an increase in the share of installations using renewable energy sources, these requirements are becoming tougher. A review of the literature revealed that most often the curve of the load duration and its distribution between blocks are used for modeling energy systems. However, since this method does not reflect a chronological sequence, it can only be used if there are no difficulties with ensuring power balance. Along with this, when the share of CHP and nuclear power plants is high, to maintain a balance of power one must know the parameters and a set of powered equipment not only currently but, also, in the previous period. But this is impossible if a curve of load duration is used. For modeling, it is necessary to use an hourly load curve and to calculate the state of the energy system for each subsequent hour in chronological order. In the course of a comparative analysis of available computer programs, it was not possible to identify a suitable model among the existing ones. The article presents a mathematical model developed by the authors, which makes us possible to simulate the operation of a power engineering system with a large share of NPP and CHPP while maintaining the power balance for each hour of the forecast period. Verification of the proposed model showed good accuracy of the methods used.

The influence of technological factors on the nature of the distribution of residual stresses on the surface of the workpiece during cutting

2021 ◽  
pp. 34-43
Author(s):  
A. A. Chudina
Keyword(s):  
Surface Layer ◽  
Residual Stresses ◽  
Experimental Studies ◽  
Cutting Speed ◽  
Chemical Properties ◽  
Operating Conditions ◽  
Workpiece Material ◽  
Technological Factors ◽  
Compressive Stresses ◽  
Compressive Residual Stresses

This article describes the basic information about the residual stresses that occur as a result of mechanical processing. The influence of such technological factors as geometric parameters of the cutting part of the tool, physical and chemical properties and structural and phase state of the workpiece material to be processed, cutting modes (feed, cutting speed, cutting depth) and lubricating and cooling technological means on the nature of the distribution of residual stresses in the surface layer of the workpiece is studied. The literature sources that present experimental studies of the influence of the above factors are analyzed. As a result, it was found that the negative front angle contributes to the appearance of compressive residual stresses on the surface. It was established that an increase in the area of the wear surface leads to a decrease in compressive stresses and the appearance of tension stresses. An increase in the cutting speed leads to a decrease in the amount of tension stresses. However, an increase in the speed when turning steel 45 does not lead to compressive residual stresses, as the heat factor will prevail during processing, and when turning steel 309, a high cutting speed will contribute to the hardening of the surface layer and, as a result, the appearance of residual compressive stresses. Depending on the ductility of the material, an increase in the feed can lead to both compressive residual stresses and tension stresses. This is due to the fact that when using other materials, heating can lead to quenching or tempering of the surface layer and, accordingly, to other results that will depend on the phase structural transformations occurring in the material. However, the effect of cutting coolant is ambiguous and will depend on how much heat is released in the cutting area. Thus, knowing the operating conditions of the product, it is possible to adjust the nature of the distribution of residual stresses on the surface by changing certain technological factors.

scholarly journals Key Barriers of Digital Transformation of the High-Technology Manufacturing: An Evaluation Method

2021 ◽  
Vol 13 (20) ◽  
pp. 11153
Author(s):  
Alexey Borovkov ◽  
Oleg Rozhdestvenskiy ◽  
Elizaveta Pavlova ◽  
Alexey Glazunov ◽  
Konstantin Savichev
Keyword(s):  
Quality Of Life ◽  
Evaluation Method ◽  
Digital Transformation ◽  
Engineering Industry ◽  
Power Engineering ◽  
Advanced Manufacturing ◽  
Engineering Company ◽  
Advanced Manufacturing Technologies ◽  
Manufacturing Technologies

It is acknowledged that quality of life is related to economic development in a country or region. The impact of the ongoing transfer to the digital economy on economic growth, sustainable development, and quality of life has been a recent academic focus, finding that the development of digitalisation of the economy and society is happening at a comparable pace. Yet, despite the availability of governmental support and overall strategic orientation of top managers, there is evidence of low digital/advanced manufacturing technologies adoption readiness across economic sectors. Therefore, the object of the research is the digital/advanced manufacturing technologies adoption readiness, which can be assessed on both industrial and organisational levels. The authors carried out an expert poll that has shown low digital/advanced manufacturing technologies adoption readiness on the industrial level (average readiness of 2.18 across estimated industries). For this reason, the focus subject of the research is the evaluation method for determining barriers of digital transformation on organisational level. The review of the academic literature and available digital maturity assessment models has shown the lack of metrics for barrier evaluation. The objective of the research is to develop a method for digital-transformation barrier evaluation. An analytical research method is used to develop a ready-to-use method in a form of a questionnaire that can be applied to measure an overall digital-transformation barrier level and identify problem areas for a manufacturing enterprise. The developed method is approbated in two large industrial companies. The overall barrier equals 39.3% for a power engineering company, which is a deterrent barrier. The overall barrier equals 75.0% for a machine-building company, which is a limiting barrier. The results of approbation correspond with results of the expert poll: the power engineering company has a lower barrier level, which is in line with the engine building and turbine engineering industry showing higher levels of readiness to adopt digital technologies. This finding supports the hypothesis about the rationality of the author’s method.

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