scholarly journals Increase of energy efficiency and competitiveness of mechanical systems on the basis of anisotropy of nonlinear frictional bonds

2019 ◽  
Vol 104 ◽  
pp. 01003
Author(s):  
Vladimir Shapovalov ◽  
Petr Shcherbak ◽  
Roman Kornienko ◽  
Vasilij Mishchinenko ◽  
Valentina Feizova
Keyword(s):  
Energy Efficiency ◽  
Friction Factor ◽  
System Reliability ◽  
Mechanical Systems ◽  
Dynamic Processes ◽  
Intensity Coefficient ◽  
Interaction Dynamics ◽  
Friction Units ◽  
Friction Surfaces

Interaction dynamics of contacting micro- and macroroughnesses of friction surfaces defines the main tribocharacteristics: friction factor, a wear-out type, its intensity, coefficient of energy efficiency of all the system. Reliability and energy efficiency of mechanical systems substantially depend on reliability and energy efficiency of their friction units. In their turn, reliability and energy efficiency of friction units are defined by interaction of the dynamic processes happening in frictional and mechanical subsystems.

scholarly journals Technology to Increase Hydrocarbon Wear Resistance of Friction Units of Hydrogen Aggregates

2019 ◽  
Vol 297 ◽  
pp. 09001 ◽  
Author(s):  
Mikhail Shalygin ◽  
Sergei Kuznetsov
Keyword(s):  
Wear Resistance ◽  
Steel Surface ◽  
Friction Pair ◽  
Dehydration Process ◽  
Diffusion Capacity ◽  
Friction Units ◽  
Surface Irregularities ◽  
Friction Surfaces ◽  
Technological Methods ◽  
Wear Tests

The causes of hydrogen wear of the friction surfaces involved in hydrocarbon transfer and distillation processes are considered. Some technological methods for reducing the hydrogen wear of parts and friction units operating in hydrocarbon environment are given. A comprehensive technology for obtaining the properties of the surface layer is proposed, which provides an increase in the wear resistance of a friction pair and smoothing the surface roughness. The increase in wear resistance is based on several mechanisms: (1) decreasing biographical hydrogen due to the dehydration process; (2) smoothing surface irregularities by saturating the surface with silicon; (3) reducing the diffusion capacity of the steel surface caused by diffusion siliconizing; (4) reducing grain size of the material. Comparative wear tests were carried out, which showed the effectiveness of the proposed methods.

Reliability Simulation and Prediction of Mechanical Equipment for Maintenance

2010 ◽  
Vol 139-141 ◽  
pp. 1060-1063
Author(s):  
Liang Pei Huang ◽  
Zheng Li Gong ◽  
Wen Hui Yue
Keyword(s):  
Service Life ◽  
Mechanical System ◽  
Density Function ◽  
System Reliability ◽  
Mechanical Systems ◽  
Mechanical Equipment ◽  
Time To Failure ◽  
Reliability Model ◽  
Estimate Reliability ◽  
Maintenance Policies

The mechanical equipment faults result from parts failure in the period of service time, due to reassembly and maintenance, the reliability model for mechanical equipment is broken, so it is necessary to research and estimate the safety reliability of mechanical system. Based on the time-to-failure density function of parts, the mechanical system reliability model is constructed to track the change course of age structure of part population for the mechanical systems that are reassembled and maintained. By means of simulation of the system reliability model, concerned parameters with mechanical systems service life are defined, it is discussed how the time-to-failure density function have influence on the service life for mechanical systems undergoing reassembly and maintenance. It is significant to estimate reliability and failure rate of systems and to establish reasonable maintenance policies.

scholarly journals Improvement of the tribological properties of heavy-loaded friction units “Centre block-footstep bearing” of a freight car

2021 ◽  
Vol 2131 (5) ◽  
pp. 052033
Author(s):  
A Sychev ◽  
V Avilov ◽  
M Savenkova ◽  
E Luneva ◽  
A Sychev
Keyword(s):  
Service Life ◽  
Tribological Properties ◽  
Friction Unit ◽  
Inorganic Polymers ◽  
Adhesion Properties ◽  
Friction Units ◽  
Physical Chemical ◽  
Operational Tests ◽  
Freight Car ◽  
Friction Surfaces

Abstract Various problems and different approaches of solution of such a problematic unit as “centre block-footstep bearing” of freight cars are discussed in the paper. The methods of improving the tribological properties of this friction unit by means of material modification of friction surfaces and perfection of physical, chemical and tribological properties of the used lubricants were studied. Grease lubricants common for friction units of railway machinery were used after being modified with inorganic polymers based on double metaphosphates. Bench and operational tests of the developed additive of the polymeric double metaphosphates were carried out. This additive reduces wear and increases the service life of the friction unit, due to the better adhesion properties of this additive. The variants with a change in the geometry of the contact surface of the disk between the bolster and the “centre block-footstep bearing” arrangement of the car are considered. Simulation of the parameters of movement in curved sections is proposed.

Study on Reliability of Mechanical Systems Based on Petri Nets and Failure Dependence

2012 ◽  
Vol 538-541 ◽  
pp. 2892-2896
Author(s):  
Qi Guo Hu
Keyword(s):  
Petri Nets ◽  
Mechanical System ◽  
Intermediate State ◽  
Systems Analysis ◽  
System Reliability ◽  
Mechanical Systems ◽  
Complex Relationship ◽  
Intersection Operation ◽  
Failure Dependence ◽  
Stochastic Event

Mechanical systems is vulnerable to be influenced of its structure and human factors for its subsystems, components and the complex relationship between each unit, causing the mechanical systems to be failed, which severely affects the reliability of the mechanical systems. based on Petri nets models of mechanical systems analysis, from safety, intermediate and failure three aspects, 3-level working model of “safety-intermediate-failure” is introduced to reflect the reliability (functioning fully) of mechanical systems, intermediary transition between reliable and failure, failure (can not work). Through using the union and intersection operation of stochastic event, and considering the different values of the related failure parameters among basic events which impacts on the reliability of mechanical system, eventually the calculation of mechanical system reliability vector with the intermediate state is established.

scholarly journals CLASSIFICATION OF STRENGTHENING TECHNOLOGIES, COVERING AND RESTORATION OF FUEL EQUIPMENT DETAILS OF DIESEL ENGINES

2019 ◽  
Vol 14 (3) ◽  
pp. 128-132
Author(s):  
Саид Шарифуллин ◽  
Said Sharifullin ◽  
Наиль Адигамов ◽  
Nail Adigamov ◽  
Павел Тополянский ◽  
...  
Keyword(s):  
Diesel Engines ◽  
Base Material ◽  
Atmospheric Pressure Plasma ◽  
High Heat ◽  
Technical Documentation ◽  
Wear Resistant Coatings ◽  
Thin Film Coatings ◽  
Friction Units ◽  
Urgent Task ◽  
Friction Surfaces

During operation, any technical product with friction units, as parts wear out, loses its working capacity and as a result cannot perform the specified functions with the parameters, established by the requirements of technical documentation. Today, the technological capabilities of manufacturing various machines and mechanisms have been exhausted throughout the world without noticeable wear on the mating surfaces of friction units. Depreciation is practically impossible to exclude. Therefore, a search for new ways to extend the life of technical devices by exposing them to friction surfaces is an urgent task. These requirements apply to the fuel equipment of automotive and combine diesel engines. In this paper, we analyze the known covering technologies for hardening and restoration of fuel equipment parts. The methodology of choosing the optimal covering process with the aim of hardening and restoration of parts of fuel equipment is formulated. In accordance with this concept of choosing a technology to increase the durability of fuel equipment parts, plasma finish hardening with the application of multilayer wear-resistant coatings is a promising technology. The paper presents the results of a study of the physicomechanical properties of diamond-like coverings of the DLCPateks type (a-C:H/a-SiOCN) obtained on friction surfaces by transporting an atomic and molecular stream of particles of liquid chemical compounds by a plasma jet of an atmospheric pressure plasma arc torch. The layer formed on the working surfaces is a non-metallic amorphous multilayer covering with a low coefficient of friction, increased microhardness, chemical inertness, hydrophilicity, high heat resistance and dielectric characteristics. In order to minimize possible defectiveness of the base material at the final stage of manufacturing parts of fuel equipment, it is proposed to apply thin-film coatings on them.

scholarly journals Reconstruction of Turbomachines on the Basis of the Flow Structure Visual Diagnostics

2020 ◽  
Vol 22 (2) ◽  
pp. 405-414
Author(s):  
Vasyl Arsiri ◽  
Oleg Kravchenko
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Flow Structure ◽  
Specific Energy ◽  
Specific Energy Consumption ◽  
Dynamic Processes ◽  
Hydraulic Efficiency ◽  
Different Types ◽  
Increase In Productivity

AbstractThe indicator of the quality of modern turbomachines is only the coefficient of efficiency, which characterizes the ratio of the useful work of compressors or fans to the energy expended on the drive. For the analysis of the quality of the motion, processes in flow parts, the values of resistances are used which are difficult to be considered as an indicator of the efficiency of dynamic processes. The report presents the results of visual diagnostics of the structure of flows during the movement in the elements of turbomachines, as well as options for improving the geometry of the flow parts - in the inlet pipes, impellers.For the analysis of the efficiency of the motion of liquids and gases in flowing parts, a calculated index is proposed - the coefficient of hydraulic efficiency of dynamic processes. The joint use of two indicators - the efficiency of transformation of different types of energy (efficiency of turbomachines) and the efficiency of dynamic processes in flowing parts allows us to develop and to analyze the results of reconstruction of turbomachines. Reconstruction of turbomachines with the purpose of improving the geometry of the flow parts provides an increase in productivity of turbines, compressors, fans and pumps, while reducing the specific energy consumption for the processes of compression and transport of liquids and gases. Optimization of turbomachines flow parts based of flow structure visual diagnostics allows to reduce noise and vibration, as well as to solve other problems.

MAGNETIC FIELD IMPACT UPON TRIBOTECHNICAL CHARACTERISTICS OF SLIDING FRICTION PAIRS WITH RESPECT TO FRICTION SHOCK ABSORBERS

2020 ◽  
Vol 2020 (11) ◽  
pp. 4-11
Author(s):  
Victor Tikhomirov ◽  
Aleksandr Gorlenko ◽  
Stanislav Volohov ◽  
Mikhail Izmerov
Keyword(s):  
Magnetic Field ◽  
Friction Factor ◽  
Sliding Friction ◽  
Friction Pair ◽  
Wear Intensity ◽  
Friction Contact ◽  
Positive Effects ◽  
Investigation Methods ◽  
Friction Surfaces ◽  
The Magnetic Field

The purpose of the work is to examine magnetic field impact upon properties of friction steel surfaces at “pin-disc” tests. The magnetic field impact upon a friction contact with the substantiation of the mechanism of its impact is proved experimentally, and also the results bringing to positive effects for friction pairs are emphasized. The analysis of experiment results has shown that a friction factor can be increased by 88% as compared with the version without magnetic field impact upon friction pair. At that under the magnetic field impact wear intensity becomes less for about half, and also friction surfaces quality becomes better as compared with the tests without a magnetic field as there are no vivid traces of plowing that is explained with the wear particles elimination from the friction area under the magnetic field impact. The investigation methods: the fulfillment of laboratory physical experiments with the use of the developed and patented laboratory plant according to the “pin-disc” scheme. The investigation results and novelty: the magnetic field impact upon a value of friction force, a factor of slip and wear intensity of friction surfaces is determined. The conclusion: it is possible to control a friction factor and wear intensity through the magnetic field impact upon a friction contact.

Laser Modification: Increasing the Wear Resistance of Friction Surfaces

2020 ◽  
Vol 836 ◽  
pp. 104-110
Author(s):  
V.I. Shastin ◽  
S.K. Kargapol’tsev
Keyword(s):  
Wear Resistance ◽  
Surface Layer ◽  
Theoretical Model ◽  
Laser Processing ◽  
Microstructural Analysis ◽  
Friction Units ◽  
Special Surface ◽  
Machine Parts ◽  
Friction Surfaces ◽  
Tribological Parameters

The article deals with topical issues of studying the physical, mechanical and tribological parameters of the surface layer of machine parts subjected to laser processing. Various options for modifying mating surfaces are evaluated and analyzed. The data of microstructural analysis and indicators of wear resistance are presented. A theoretical model of the wear of heat-strengthened surfaces is proposed, explaining the mechanism for increasing their wear resistance as a result of homogenization of the microstructure of a special surface layer with increased bearing capacity. It is experimentally confirmed that the greatest wear resistance is observed in friction units during mutual modification of mating surfaces.

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