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 Determining the residual resource of the hammer crushers’ rotor bearings

2020 ◽  
Vol 17 ◽  
pp. 00239
Author(s):  
Nail R. Adigamov ◽  
Rafis R. Shaikhutdinov ◽  
Ildus H. Gimaltdinov ◽  
Rishat R. Akhmetzyanov ◽  
Rafik S. Basyrov
Keyword(s):  
Input Data ◽  
Production Efficiency ◽  
Residual Life ◽  
Animal Husbandry ◽  
Scientific Result ◽  
Rolling Bearings ◽  
Agricultural Enterprises ◽  
Sudden Failure ◽  
The Republic ◽  
Rotor Bearings

The practice of operating machinery and equipment that are used in animal husbandry and in the processing of its products has shown low reliability of feed crushers. As of 01.01.2019, in the agricultural enterprises of the Republic of Tatarstan there are about 1200 machines for grinding feed, of which 800 pcs. are hammer crushers. Most of these crushers have a service life of 10 to 13 years and are objects with low reliability. Mostly emergency stops occur due to the destruction of the rotor bearings. In the event of a sudden failure, unplanned repairs and a decrease in production efficiency occur. At the Department of Operation and Repair of Machines of Kazan State Agrarian University, research was carried out and a scientific result was obtained, which was implemented in the adapter to the vibrometer to determine the residual life of rolling bearings. Input data for this device were obtained during operational research and further analysis of the data.

scholarly journals AVIATION ENGINES DIAGNOSTICS BY ESTIMATING THE METAL CONTAMINATION IN OILS

2019 ◽  
Vol 22 (3) ◽  
pp. 35-44 ◽  
Author(s):  
K. I. Gryadunov ◽  
A. N. Kozlov ◽  
M. L. Nemchikov ◽  
I. S. Mel’nikova
Keyword(s):  
Residual Life ◽  
Operating Time ◽  
Diagnostic Methods ◽  
Civil Aviation ◽  
Aviation Gasoline ◽  
Proper Training ◽  
And Performance ◽  
Diagnostic Complex ◽  
Simplified Procedures ◽  
Aviation Engines

Current trends of civil aviation development show a significant increase in the number of aircraft with aircraft piston engines. The Ministry of Transport of the Russian Federation is preparing a draft order on amendments to the Federal aviation rules for the preparation and performance of flights in civil aviation (FAP-128), which stipulate for simplified procedures of paid excursion flights implementation for light and ultralight aircraft and helicopters. It is obvious that this circumstance will significantly affect the expansion of the fleet of these aircraft. Accordingly, the state of piston engines operating on aviation gasoline value questions are becoming increasingly relevant. The current problems of aviation engines diagnostics by metal contents in oils are observed in the article. Their bugs, possible ways of solving this problems and bugs, actual developments in this direction are shown. The application examples of early diagnostic methods using the automated diagnostic complex “Prisma” are shown. The oil samples taken from An-2 aircraft АШ-62ИР piston engine analyses results attract the most interest. They show that with proper training of personnel the valuable information coming from the oil samples can be a source of important conclusions not only in aircraft engines accessories and assemblies state value, but also others systems, and also conclusions about the quality of fuel and lubricants used. Estimating the residual life method of the engine at various stages of its operating time on the metal content in the oils and the procedure for oil selecting, allowing to obtain reliable results, are suggested.

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.

scholarly journals Influence of radial clearance on nonlinear dynamics of a two-span three-support rotor system

2021 ◽  
Vol 233 ◽  
pp. 04012
Author(s):  
HE Xing ◽  
WU Yi-ming ◽  
LI Mo ◽  
ZENG Fan
Keyword(s):  
Periodic Motion ◽  
Rotor System ◽  
System Model ◽  
Radial Clearance ◽  
Structural Form ◽  
Single Cycle ◽  
Rolling Bearings ◽  
System A ◽  
Runge Kutta Method ◽  
Nonlinear Dynamic Characteristics

Aiming at the structural form of a certain rotor system, a double-span three-support rotor system model is established. It is supported by three rolling bearings and has a typical nonlinear characteristic. The fourth-order Runge-Kutta method is used to solve the differential equations and analyze the nonlinear dynamic characteristics of the rotor system when the radial clearance of the bearing changed. The research results: with the increase of the rear bearing radial clearance, the rotor system performs single cycle, periodic two and pseudo-periodic motion. With the three location bearing radial clearance increases, the rotor system performs single cycle, periodic two and periodic four motion. When the radial clearance is bigger, the rotor system performs two periodic motion. The influence law of radial clearance on double span three - braced rotor system is shown.

A degradation model for maintenance improvement in respect of cost and availability

2015 ◽  
Vol 21 (1) ◽  
pp. 55-69 ◽  
Author(s):  
Christophe Letot ◽  
Pierre Dehombreux ◽  
Edouard Rivière-Lorphèvre ◽  
Guillaume Fleurquin ◽  
Arnaud Lesage
Keyword(s):  
Preventive Maintenance ◽  
Residual Life ◽  
Operating Time ◽  
Hitting Times ◽  
Mean Residual Life ◽  
Reliability Model ◽  
Content Type ◽  
Degradation Data ◽  
Specific Item ◽  
The Mean

Purpose – The purpose of this paper is to highlight the need for degradation data in order to improve the reliability and the mean residual life estimation of a specific item of equipment and to adapt the preventive maintenance tasks accordingly. Design/methodology/approach – An initial reliability model which uses a degradation-based reliability model that is built from the collection of hitting times of a failure threshold. The proposed maintenance model is based on the cost/availability criterion. The estimation of both reliability and optimum time for preventive maintenance are updated with all new degradation data that are collected during operating time. Findings – An improvement for the occurrences of maintenance tasks which minimizes the mean cost per unit of time and increases the availability. Practical implications – Inspection tasks to measure the degradation level should be realized at least one time for each item of equipment at a specific time determined by the proposed methodology. Originality/value – The introduction of a criterion which helps the maintainer to decide to postpone or not the preventive replacement time depending on the measured degradation level of a specific item of equipment.

scholarly journals Classification of quality conditions of a traction motor frame insulation of locomotives

2019 ◽  
Vol 294 ◽  
pp. 03002
Author(s):  
Michail Kapitsa ◽  
Vasiliy Laguta ◽  
Yuriy Kozik
Keyword(s):  
Residual Life ◽  
Operating Time ◽  
Statistical Characteristics ◽  
Traction Motor ◽  
Limit Values ◽  
Voltage Curve ◽  
Frame Insulation ◽  
Recovery Voltage ◽  
Insulation Condition

The objective of the article is to determine the quality conditions of a locomotive traction motor frame insulation based on observations over the recovery voltage and classification of a tested insulation wear degree as well as to determine estimates of operating time until the insulation restoration or replacement with a new one. To classify the insulation quality conditions and to forecast its residual life until the restoration, a cluster analysis and discriminant analysis are used based on indicators reflecting the properties of an insulation recovery voltage curve. The study defines an information content received from frame insulation recovery voltage readings as compared with its resistance from the perspective of testing the insulation condition and predicting its residual life. Statistical characteristics of clusters corresponding to the insulation condition stages allow determining the limit values of predicting parameters and estimating the residual insulation life prior the restoration. To classify the insulation condition, an integrated evaluation of the insulation condition quality is proposed. Integrated evaluation is performed according to the recovery voltage curve and is used as an indicator during clustering. An experimental study of the proposed method practically confirmed its effectiveness.

scholarly journals PETROLEUM AND BITUMEN CONTAINING AND INDUSTRIAL ANTHROPOGENIC MATERIALS FOR CONSTRUCTION OF LONG-LASTING ROARDS

Neft i gaz ◽  
2020 ◽  
Vol 5 (119) ◽  
pp. 121-133
Author(s):  
B.A. ASMATULAYEV ◽  
Keyword(s):  
Operating Time ◽  
Power Saving ◽  
Road Transport ◽  
Road Maintenance ◽  
Technical Program ◽  
Resource Saving ◽  
Recoverable Resources ◽  
The Republic ◽  
High Level ◽  
Anthropogenic Wastes

This paper raises problem issues of technical conditions of the roads in the Republic in connection with the address of Kassym-Zhomart Tokayev, the President of the country to the people of Kazakhstan.The main problem is poor condition of roads infrastructure resulting in a high level of accidents on dual highways. The second problem is slow rate of roads’ construction and reconstruction according to outdated designing methods and traditional construction technologies for a short operating time of not more than 15-20 years that does not comply with worldwide standards of repair-free service life of roads of 50 years and more. Motorization of the country and freight traffic increases by 25-40% annually, the road load increased 2-3 times resulting in intensive destruction of outdated roads pavements. In connection with this the volume of repairs with respect to costs exceeds more than 50% of total road industry financing. The third problem is a high cost of roads construction. Cost plus technologies are still being widely applied in Kazakhstan. At the same time industrial waste discharge of Kazakhstan’s enterprises accumulated more than 45 billion tons of anthropogenic wastes including petroleum and bitumen containing anthropogenic materials with the application of which innovative resource-saving and power-saving nanotechnologies and nanostructured long-life materials were developed. At the same time, it is possible to reduce the cost of construction and expenses for road maintenance by 2-3 times within 50 years. In addition, to accelerate construction and repairs of 1-2 category roads by 2-3- times, while 3-4 category by 5-6 times. The scientific and technical program headed by national Engineering Academy of the Republic of Kazakhstan for 2021-2023 “To develop and implement efficient technologies of cast-insitu construction of road-transport structures according to world standards with a complex recycling of industrial anthropogenic wastes and recoverable resources” is developed for wide application of nanotechnologies and nanostructured materials in roads construction.

Study of the damage to 12Cr18Ni10Ti steel samples under low cycle fatigue using methods of nondestructive control

2021 ◽  
Vol 87 (5) ◽  
pp. 61-67
Author(s):  
A. A. Khlybov ◽  
Yu. G. Kabaldin ◽  
D. A. Ryabov ◽  
M. S. Anosov ◽  
D. A. Shatagin
Keyword(s):  
Structural Changes ◽  
Residual Life ◽  
Low Cycle Fatigue ◽  
Fatigue Cracks ◽  
Operating Time ◽  
Test Material ◽  
Magnetic Characteristics ◽  
Propagation Time ◽  
Cycle Fatigue ◽  
Number Of Cycles

The possibility of determining the degree of damage to flat samples in the area of low-cycle fatigue at the stage of accumulation of scattered damage before the appearance of a macroscopic crack is demonstrated. Flat samples were tested for cantilever bending at room temperature with a constant loading amplitude until a fatigue crack appeared. Austenitic steel 12Cr18Ni10Ti was used as a test material. The velocity (propagation time) of elastic waves in the material and the coercive force were measured upon testing at intervals of 500 cycles. The zone of damage development was analyzed and value of hardening (based on microhardness measurements) was determined within 15 mm of the developed crack. The analysis of the images of the alloy microstructures in the zone of the most likely crack propagation was performed following different number of cycles at the same point on the sample surface. The structural changes (γ – α transition (formation of martensite deformation)) that occur during cyclic loading, as well as nucleation and development of damage, followed by the formation of fatigue cracks, inevitably lead to changes in the elastic and magnetic properties of the material. At the initial stages of loading, we observed changes in the initial (both acoustic and magnetic) characteristics of the material, which later became stable or changed slightly. When operating time exceeded 80 % of the number of cycles before failure, a significant change in the measured parameters occurred. The obtained dependences of the acoustic and magnetic characteristics of the material provide reliable information about the current damage and can be used in estimating the residual life of the structures made of 12Cr18Ni10Ti steel.

Diesel engine condition assessment by operating oil parameters

2021 ◽  
pp. 222-224
Author(s):  
Keyword(s):  
Diesel Engine ◽  
Residual Life ◽  
Operating Time ◽  
Condition Assessment ◽  
Technical Condition ◽  
Engine Oil ◽  
Point Density ◽  
The Given ◽  
The Relationship ◽  
Engine Condition

The article substantiates the relationship between the given values of the parameters of the working oil and the residual life or failure of the diesel engine at low oil operating time (up to 4 thousand km). The results of studies of changes in the alkaline number, viscosity, flash point, density in the process of engine oil on cars KAMAZ-EURO, graphically presents the state of the engines known as a result of the operation of the dependencies and standards of the parameters of the operating oil. Keywords oil conditions; operating time; technical condition; residual life; alkaline number; viscosity

Torsional Vibrations of the Steam Turbine Shaft Line and Estimation of the Residual Life of Its Elements

2020 ◽  
Vol 63 (6) ◽  
pp. 91-98
Author(s):  
Vladimir Grabovskii ◽  
Keyword(s):  
Steam Turbine ◽  
High Speed ◽  
Residual Life ◽  
Operating Time ◽  
Electromagnetic Transients ◽  
Torsional Vibrations ◽  
Steam Turbines ◽  
Shaft Line ◽  
Operating Modes ◽  
Design Life

A comparative quantitative assessment of the damage and residual life of the shaft line elements for differ-ent types of high-power steam turbines at the end of their design life is made by mathematical modeling. The analysis covers all elements of the shaft line: from the steam turbine Central pump to the turbine generator ex-citer. The simulated circuit includes turbo generators, transformers, gate converters, AC and DC power lines. When modeling, an approach is used from the position of proper coordinates, which provides maximum meth-odological consistency of the models of the listed devices and allows you to directly reproduce electromagnetic and mechanical transients with the determination of instantaneous values of currents, voltages, electromagnet-ic and torsional moments. To estimate damage, we used the deformation criterion for soft and hard loads in the zone of low-cycle and force criterion in the zone of multi-cycle fatigue. The influence of the number of starts and running time of a steam turbine on the damage and residual life of its shaft elements is studied. When de-termining the remaining life, in addition to starts, other abnormal operating modes of the turbo generator were taken into account during the turbine operating time: short circuits and their disconnections, unsuccessful high-speed automatic re-activation, subsynchronous resonance due to both the operation of the control system of the PPT and the automatic generator excitation regulator. The influence of attenuation of electromagnetic transients in the generator and damping of torsional vibrations on the degree of reduction of the residual life of the shaft elements is analyzed. The results obtained can be used for a comprehensive solution of the issue of further operation of steam turbines that have spent their design life.

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