scholarly journals ABOUT ESTIMATION OF THE INFLUENCE OF NON-UNIFORMITY OF INITIAL STATES ON LIFETIME OF FRICTION PAIRS AND TRIBO-FATIGUE SYSTEMS

2021 ◽  
Vol 2 (55) ◽  
pp. 88-96
Author(s):  
A.V. Bogdanovich ◽  
Keyword(s):  
Sliding Friction ◽  
Operating Time ◽  
Relative Number ◽  
Technical Condition ◽  
Rolling Bearings ◽  
Integral Characteristics ◽  
Circular Contour ◽  
Initial States ◽  
Number Of Cycles ◽  
Rate Dynamic

The article analyzes relationships of the non-uniformity of the initial states and the lifetime of friction pairs and tribo-fatigue systems based on the results of the inspection of the technical condition after operating time and laboratory tests. The non-uniformity of the initial states is determined by the variation within the tolerances of the geometry of the elements due to the manufacturing technology, and its influence on the wear rate, dynamic characteristics and lifetime of mechanical systems is estimated on the example of automobile sliding friction bearing pairs and rolling bearings. A laboratory experiment to assess the performance of a model of a tribo-fatigue system “shaft (steel 45) — roller (25ХГТ (25KhGT) steel)” due to local violation of the shaft geometry during rolling is analyzed. The correlation equations are given that link the integral characteristics of the local process of wear-fatigue damage, based on measurements of the circular contour of the test specimen (coefficients of asymmetry and non-uniformity), with the relative number of cycles until the limiting wear of the tribo-fatigue system “shaft (steel 45) — liner (silumin)” under sliding friction is reached.

Efficiency of application of the phase-chronometric method and neurodiagnostics for monitoring the degradation of rolling bearings during operation

2020 ◽  
pp. 43-50
Author(s):  
A.S. Komshin ◽  
K.G. Potapov ◽  
V.I. Pronyakin ◽  
A.B. Syritskii
Keyword(s):  
Life Cycle ◽  
Wavelet Analysis ◽  
Metrological Support ◽  
Rolling Bearing ◽  
Technical Condition ◽  
Measurement Information ◽  
Rolling Bearings ◽  
Vibration Diagnostics ◽  
Bearing Life ◽  
Alternative Approach

The paper presents an alternative approach to metrological support and assessment of the technical condition of rolling bearings in operation. The analysis of existing approaches, including methods of vibration diagnostics, envelope analysis, wavelet analysis, etc. Considers the possibility of applying a phase-chronometric method for support on the basis of neurodiagnostics bearing life cycle on the basis of the unified format of measurement information. The possibility of diagnosing a rolling bearing when analyzing measurement information from the shaft and separator was evaluated.

Contribution to Rolling Bearing Reliability Modeling

2011 ◽  
Vol 110-116 ◽  
pp. 2497-2503 ◽  
Author(s):  
Zdenek Vintr ◽  
Michal Vintr
Keyword(s):  
Operating Time ◽  
Rolling Bearing ◽  
Time To Failure ◽  
Rolling Bearings ◽  
Mean Time To Failure ◽  
Reliability Modeling ◽  
Time Between Failures ◽  
Large Groups ◽  
Mean Time

Rolling bearings are usually considered to be non-repaired items the reliability of which is characterized by mean time to failure, or so called basic rating life. Reliability describes these parameters well in case the bearings are used in operation up to the very time the failure occurs, or during the time corresponding with basic rating life. In case of railway applications the bearings are often used in large groups and are preventively replaced after much shorter operating time as compared with their basic rating life. In the article there is a model which enables us to describe the bearings reliability in this specific case and to specify a number of failures which might be expected from a group of bearings during operating time, or to determine mean operating time between failures of bearings.

Some Regularities of Life Time and Damage for the New Structural Material MoNiCa during Sliding Friction and Mechano-Sliding Fatigue

2021 ◽  
Vol 320 ◽  
pp. 90-96
Author(s):  
Aliaksandr Bahdanovich ◽  
Sergei Sherbakov ◽  
Ivan Lis ◽  
Regita Bendikiene ◽  
Ramūnas Česnavičius ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Structural Material ◽  
Mechanical System ◽  
Sliding Friction ◽  
Limit State ◽  
High Strength ◽  
Life Time ◽  
Average Wear ◽  
The Republic ◽  
Number Of Cycles

The results of an experimental study of damage for the structural material MoNiCa (it is high-strength cast iron VCHTG – patent of the Republic of Belarus № 15617) on sliding friction and mechano-sliding fatigue are analyzed in the report. Tests of the mechanical system shaft (a sample with a working part diameter of 10 mm made of 0.45 % carbon steel) - an insert (a prismatic counter sample with a cross section of 10 ´ 10 mm made of MoNiCa) were carried out. The kinetics of the change in average wear at 8 local points along the perimeter of the dangerous area of the sample is given for contact loads FN from 20 to 92 N of the mechanical system under study with MoNiCa inserts without heat treatment and with heat treatment. The test results of the system under study are also presented in the form of sliding friction and mechano-sliding fatigue curves in coordinates of the contact load FN – the number of cycles N until the limit state.

scholarly journals Organization of the Process of Productive Operation of Equipment as One of the Necessary Conditions of Rational Production Organization

2020 ◽  
Vol 9 (3) ◽  
pp. 3589-3593
Keyword(s):  
Labour Productivity ◽  
Unit Cost ◽  
Operating Time ◽  
Production Capacity ◽  
Working Hours ◽  
Technical Condition ◽  
Necessary Condition ◽  
Equipment Maintenance ◽  
Organization Of Production ◽  
Production Organization

The service and equipment repairing process is the necessary condition for the growth of production capacity of enterprises, and thereafter it predetermines the approach for organization of production and upbuilding of production streams. In the article different options of reduction of working hours loss are considered, due to equipment downtime elimination because of repair and equipment maintenance on the reason of the increased operation. Also, in the article reserves of growth of labour productivity and reductions of unit cost are identified. It is proved, that current equipment monitoring allows to eliminate different defects in rationing of operating time of the equipment, it also allows to reach the permanent production’s rhythms, to increase the monitoring level, to provide the timeliness delivery of materials and components. As the example, in the research was used factual material of planned measurement of technical condition of the equipment on a separate production of GAS Group, methods of monitoring of technical condition and productive equipment maintenance and standard criteria of the equipment’s condition were developed.

Maintenance of Power Equipment System Based on the Methods of Diagnosis and Control of Technical Condition

2018 ◽  
pp. 421-448 ◽  
Author(s):  
Dmitry Strebkov ◽  
Alexey Nekrasov ◽  
Anton Nekrasov
Keyword(s):  
Operating Time ◽  
Electrical Equipment ◽  
Technical Condition ◽  
Spare Parts ◽  
Actual Condition ◽  
Power Equipment ◽  
Service Strategy ◽  
Electrical Systems ◽  
Preventive Actions ◽  
Equipment System

Maintenance of the power equipment system is based on the industry standard of averaged volumes of standard maintenance and repair of power equipment, frequency and duration of the preventive measures, the nomenclature and consumption of materials and spare parts to perform operations. One of the more efficient uses of electrical equipment is to improve its maintenance system through the development and implementation of service strategies for the actual condition. The work proved the necessary conditions for the realization of electric service strategy on defining the main diagnostic parameter. The general mathematical model is proposed to implement the service strategy. The model is based on a study of basic parameters using random monotone normal type of process and diagnostic controlled parameter with three discrete product states (working, the state of preventive actions, and failure) and continuous operating time. The results of studies of the new techniques development for improving the operation of electrical systems are presented.

RANDOM SHUFFLING OF SWITCHING PARAMETERS IN A MODEL OF GENE EXPRESSION REGULATORY NETWORK

2005 ◽  
Vol 05 (01) ◽  
pp. 75-95 ◽  
Author(s):  
D. VOLCHENKOV ◽  
R. LIMA
Keyword(s):  
Gene Expression ◽  
Regulatory Networks ◽  
Relative Number ◽  
Error Tolerance ◽  
Time Model ◽  
Discrete Time Model ◽  
Regulatory Processes ◽  
Large Gene ◽  
Genetic Switches ◽  
Number Of Cycles

A discrete time model of large gene expression regulatory networks is considered. Transcriptional degrees of regulations and activation thresholds are shuffled randomly that helps to study the highly reproducible dynamical patterns of regulatory processes in a lack of empirical data concerning genetic switches. The multistationarity and multiperiodicity of oscillations exhibited by the system relay upon the feedback circuits. Statistics of their appearance depends upon the relative number of negative regulations between the genes of network, the number of cycles in the maximal graph, and their lengths. The model defined on the scalable graphs demonstrates the high persistence in oscillations and the high error tolerance.

scholarly journals Diagnostics of the technical condition and predic-tion of accident-free guaranteed operating time of heavily loaded machines gear wheels

2021 ◽  
pp. 54-61
Author(s):  
Anatoliy Gaydamaka ◽  
Yurii Muzykin ◽  
Volodymyr Klitnoi
Keyword(s):  
Least Squares Method ◽  
Limit State ◽  
Operating Time ◽  
Technical Condition ◽  
Final Decision ◽  
Heavy Duty ◽  
Gear Wheels ◽  
Scheme Selection ◽  
Operation Results ◽  
Selection Of

Problem. This article highlights the current state of diagnostics of gears on the level of accumulated fatigue damage in operation. The generalization of the known information on determination of a technical condition of separate gear wheels, especially with big modules (m> 20 mm), allows to outline prospects of development of such diagnostics of a technical condition of gear wheels directly in the course of operation. Goal. The goal of this study is to develop an algorithm for diagnosing the technical condition and forecasting a fault-free operation of the gears of heavy-duty machines. Methodology. The least squares method and the confidence interval method are used to predict accident-free guaranteed gear operation. Results. A procedure for diagnosing the technical condition of gears by measuring the hardness of the metal has been developed, which includes five main stages: selection of the device; choice of measurement scheme; selection of the number of measurements, number and relative position of measuring points; development of a design of a template for measurements; development of a device for fastening templates. When determining the accident-free guaranteed operating time on the basis of several criteria of the limit state, the final decision is made on the criterion that determines the minimum term. Originality. The method of forecasting accident-free guaranteed operating time of gears is chosen taking into account the stages of running-in and stable in linear function accumulation of damage in operation. Practical value. The use of the developed procedure for diagnosing the technical condition of the gears of gearboxes of heavy-duty machines will significantly increase the efficiency of their operation due to the transition from scheduled preventive maintenance to maintenance according to the actual technical condition.

scholarly journals PREVENTIVE MAINTENANCE STRATEGY FOR CRUSHING EQUIPMENT

2020 ◽  
Vol 15 (3) ◽  
pp. 71-76
Author(s):  
Il'dus Gimaltdinov ◽  
Bulat Ziganshin ◽  
Ilgiz Galiev ◽  
Andrey Dmitriev ◽  
Al'bert Muhametshin ◽  
...  
Keyword(s):  
Residual Life ◽  
Operating Time ◽  
Piezoelectric Sensor ◽  
Radial Clearance ◽  
Hammer Mill ◽  
Rolling Bearings ◽  
The Republic ◽  
Diagnostic Complex ◽  
Vibration Parameters ◽  
Rotor Bearings

The research was carried out in order to develop a mathematical model and a diagnostic complex to determine the residual life of the rotor bearings of hammer crushers. Residual life information is essential for proactive maintenance and to prevent equipment crashes. To achieve this goal, Kazan State Agrarian University (Republic of Tatarstan) carried out calibration studies of the dependence of the diagnostic parameters of vibration on the value of the radial clearances of the bearings. 3610 bearings with different radial clearances (0.02 mm, 0.08 mm, 0.13 mm, 0.2 mm, 0.27 mm) were alternately installed on the rotor of the KD-2 hammer mill, from the drive pulley side and from the fan side) and recorded the vibration parameters. The information was read using a piezoelectric sensor. Signal processing was performed using a VVM-201 vibrometer. The results of mathematical processing of these data are presented in earlier publications. To determine the change in the value of the radial clearance from the operating time in hours, retrospective studies were carried out directly in the agricultural enterprises of the Republic of Tatarstan: “Shaimurzinskoe agricultural enterprise named after A.Sh. Abdreev” of Drozhzhanovskiy region, JSC “Kiyatskoe”of Buinskiy region, the agricultural production complex “Ural”of Kukmorskiy region, etc. The average operating time of the bearings of the rotor of the hammer-type KD-2 forage grinder before the onset of a pre-failure state on the drive side was 1900 ... 2000 hours, on the fan side - 2000 ... 2100 h. Based on the results of the research, the values of the radial clearances and vibration parameters of the rolling bearings of the rotor of hammer crushers were experimentally established, the regularities of the change in the radial clearance of the rolling bearings of the rotor of hammer crushers were revealed depending on the operating time. The developed mathematical models for determining the radial clearance in the rotor bearings of the hammer crusher by vibration parameters and calculating the residual life are implemented in a diagnostic complex consisting of a commercially available VVM-201 vibrometer and a residual life attachment

scholarly journals TO THE QUESTION OF THE POSSIBILITY OF DEVELOPING TOOLS AND METHODS FOR INSTRUMENTAL DIAGNOSTICS OF HEAT EXCHANGERS OF TRANSPORT EQUIPMENT IN OPERATION

2021 ◽  
pp. 60-67
Author(s):  
A.P. Poslavsky ◽  
◽  
V.V. Sorokin ◽  
A.A. Fadeev ◽  
◽  
...  
Keyword(s):  
Heat Exchangers ◽  
Objective Assessment ◽  
Operating Time ◽  
Basic Structure ◽  
Technical Condition ◽  
Practical Significance ◽  
Time Interval ◽  
Problem Situation ◽  
Resource Saving ◽  
Diagnostic Support

Heat exchangers are used to stabilize and maintain the temperature regime of various units and systems of cars. The technical condition of heat exchangers in operation is different and unstable. At a certain operating time interval, the technical condition of any of the heat exchangers can become limiting due to the influence of various kinds of operational factors. The article analyzes the possibility of improving the means and methods of diagnostic support of automobile heat exchangers in operation. In the design and manufacture of automotive heat exchangers, they are tested in specialized laboratories equipped with test stands characterized by high capital and operating costs. The use of these stands for diagnosing heat exchangers in operation is not applicable. Due to the limitations and imperfections of the known methods and means of diagnosing automobile heat exchangers in operation, an objective assessment of their current technical condition is difficult and requires the search for new, more advanced diagnostic options. The relevance of the topic of the article lies in the search for ways to improve the diagnostic support, adapted for a quantitative assessment of the technical condition of heat exchangers in operation. The aim of the work is to improve the method and means of diagnosing heat exchangers in operation on the basis of modernizing the design of the test bench for radiator modules. Potentially a possible upgrade option was chosen previously developed by the authors stand for testing modules of automobile radiators, which is distinguished by the effect of resource saving when obtaining the test result. Achievement of the goal requires updating the architecture of the structural elements of the stand, and the search for design and technological solutions that contribute to the achievement of the goal. The methodological research toolkit is based on dialectically interrelated methods: analysis of a problem situation and subsequent design and technological synthesis. Scientific novelty lies in the development of conditions for modernization, allowing to expand the functionality of the basic structure of the stand. The practical significance of the results lies in the choice of the direction of research, with a new set of technical proposals and conditions for achieving the goal of the work.

scholarly journals Promising model range career excavators operating time assessment in real operating conditions

2020 ◽  
Vol 242 ◽  
pp. 228 ◽  
Author(s):  
Sergey IVANOV ◽  
Polina IVANOVA ◽  
Sergey KUVSHINKIN
Keyword(s):  
Good Condition ◽  
Operating Time ◽  
Mining Industry ◽  
Negative Influence ◽  
Technical Condition ◽  
Operating Conditions ◽  
Economic Losses ◽  
Mining Machine ◽  
Mining Equipment ◽  
Detailed Assessment

The development prospects of the mining industry are closely related to the state and development of modern mining machinery and equipment that meet the technical and quality requirements of mining enterprises. Enterprises are focused on a quantitative assessment – the volume of mineral extraction, depending on the functioning efficiency of a promising series of mining machines, which include modern mining excavators. Downtime and unplanned shutdowns of mining excavators directly depend on the operating conditions of the mining machine, which has negative influence on the machine as a whole and its technical condition, which entails a decrease in the efficiency of using expensive mining equipment and economic losses of the mining enterprise. The rationale for external factors that affect the operating time and technical condition of mining excavators is given. For a more detailed assessment of the influence of external influences on the efficiency of operation of mining machines, the influencing factors are divided into two groups: ergatic, directly related to human participation, and factors of a natural-technogenic nature, where human participation is minimized. It was revealed that factors of a natural-technogenic nature have the greatest influence. An algorithm is proposed for a comprehensive assessment of the technical condition and forecasting of operating time both in nominal and in real operating conditions, taking into account factors of a natural and technogenic nature. It is proposed, based on the developed program for planning and evaluating the life of a mining excavator, to adjust the schedules for maintenance and repair (MOT and R) in order to minimize the number of unplanned downtime of a mining excavator and maintain it in good condition.

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