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About possibility of immediate evaluation of technical condition of mining
equipment using signal value of acoustic emission friction
To cite this article: V I Knyazkina et al 2019 IOP Conf. Ser.: Mater. Sci. Eng. 560 012068
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MEACS2018
IOP Conf. Series: Materials Science and Engineering 560 (2019) 012068
IOP Publishing
doi:10.1088/1757-899X/560/1/012068
1
About possibility of immediate evaluation of technical
condition of mining equipment using signal value of acoustic
emission friction
V I Knyazkina, K A Safronchuk and S L Ivanov
1Saint-Petersburg Mining University, 2, 21st line, Saint-Petersburg, 199106, Russia
E-mail: knyazkina.valeriya.94@mail.ru
Abstract. An experiment was conducted to confirm the reliability of the evaluation of the
technical condition of transmission elements during operation in terms of the magnitude and
nature of the acoustic emission signal, while completing the negative effect of the artificial
environment on the durability of the transmission elements. Thus, the results of the experiment
are presented where the acoustic emission signal in the friction pair was changed depending on
the pressure value in the contacting pair and the angular velocity value. The possibility of
obtaining an estimate of the technical state of the transmission elements during its operation in
terms of acoustic and emission characteristics has been experimentally confirmed.
1. Introduction
Currently the development of the mining economic sector is impossible to imagine without application
and usage of quarry and mining machines with high reliability and power. However the severe and
extreme conditions of mining machines exploitation lead to their low working time, to the significant
downtime periods for this equipment, labour intensity increase and high repair costs.
The matter for mining machines reliability is rather acute because its lifetime for open-air works
compared with that of the machines is much lower. Such machinery failures in quarry conditions have
drastic consequences with high probability [1,4,9].
An additional effective diagnostics of machines transmissions is suggested to be included into the
technology of mining machinery technical maintenance and repair (TMR). Such diagnostics is typical
for the strategy of TMR based on the actual condition [2,3], and it should help to use optimally the
mining machinery potential together with its reliability increase. Such maintenance is based on
obligatory application of the newest control and adjusting means and methods that allow finding out
the main part of different equipment defects. The maintenance is to use a complex approach to solve
the engineering and technical matters with the aim to keep the machines in workable condition. The
effective tool for such diagnostics is the estimation of the signal value in the acoustic emission range
and character caused by an interaction character of machine transmission working elements.
2. Non-destructive testing
Non-destructive testing is a wide group of analysis techniques used in science and industry to evaluate
the properties of a material, component or system without causing damage. The terms “nondestructive
examination”, “nondestructive inspection”, and “nondestructive evaluation” are also commonly used
to describe this technology. Non-destructive testing does not permanently alter the article being
MEACS2018
IOP Conf. Series: Materials Science and Engineering 560 (2019) 012068
IOP Publishing
doi:10.1088/1757-899X/560/1/012068
2
inspected, it is a highly-valuable technique that can save both money and time in product evaluation,
troubleshooting, and research.
Non-destructive testing is one part of the function of quality control and is complementary to other
long established methods. By definition non-destructive testing is the testing of materials for surface
or internal flaws or metallurgical condition without interfering in any way with the integrity of the
material or its suitability for service.
It is possible to decrease the risks of emergency failures by damages and defects early discovery
and to plan rationally the means and forces by carrying out the technical maintenance [5,4,10,12]
when providing the data analysis about the signal character and value of acoustic emission friction.
The analysis is made according to estimation results of the machinery technical condition.
To provide the transmissions work of normal mining machinery in hard ambient conditions of its
exploitation, the lubrication is to guarantee separation of contacting surfaces, to prevent galling and
sticking, to decrease wear intensiveness. Besides from the above listed requirements, the lubrication is
to have stable viscosity, low solidification temperature, good anticorrosion properties [3,6,7,11].
To estimate oils lubricating capability, it is necessary to check the real friction couple contact
condition. The signal of acoustic emission friction does not depend on temperature and contacting pair
materials, on tested lubricant properties and on the contacting square of the parts.
3. Result and Discussion
The experiments with usage of the device ARP-11 (Bearing life analyzer) produced by METKATOM
Ltd are held. In the experiments a relative index D is measured that is proportional to the value of
acoustic emission appearing in the friction couple “counterbody – plate” and to the index of friction in
the couple [2,8,10].
Figure 1 shows the changing in the signal value of acoustic emission friction described by the index
D for a sequence row of angular speeds by constant pressures in a contacting pair.
Figure 1. Value dynamics of index D depending on speed in the contacting pair
with the lubricant “Industrial oil I-20”.
The figure shows a stable existing trend of acoustic emission signal increasing together with the
angular speed increase. Herewith the higher the pressure in the contacting pair, the more intensive the
increase in index D. It bears evidence about degradation of the contacting pair friction conditions,
pressing lubrication out of the contact area and transfer from volumetric friction to dry friction.
Figure 2 demonstrates the character of acoustic emission value change described by index D for a
sequence of pressure values in a contacting pair by constant angular speeds.
Similar to the angular speed parameter influence, the trend reveals that the acoustic emission signal
value corresponding to the friction factor should change depending on pressure in the contacting pair.
Transfer to the dry friction condition by high speeds happens already according to low pressure values,
MEACS2018
IOP Conf. Series: Materials Science and Engineering 560 (2019) 012068
IOP Publishing
doi:10.1088/1757-899X/560/1/012068
3
that is, low speeds in the contacting pair in the normal conditions are kept even by significant forces
[3,5,9].
Figure 2. Value dynamics of index D depending on pressure in the contacting pair
with the lubricant “Industrial oil I-20”.
Taking into consideration the discovered trends, based on laboratory experiments it becomes
possible to find out the limit friction areas with the value lower than 4 MPa. This area is a limit
parameter for a particular lubrication type “Industrial oil I-20”. During the experiment it has been
found out that for the condition estimation, for example, of a mechanical transmission represented by a
2-stage gearbox, it is not obligatory to mount sensors on each of the components. To estimate
integrally the condition of all transmission elements and to discover those that cause most of the
problems, it is enough to determine the distinctive points on the gearbox case body. Such method
provides the possibility to simplify significantly the monitoring system to follow the technical
condition of a technically complicated object in terms of maintenance strategy on base of actual
condition. More than that, the ARP-11 device allows composing a database about the equipment
condition, and it provides the possibility to fix degradation processes in dynamics [2,11].
4. Conclusion
The important rule aimed to provide the exploitation reliability of transmission elements in mining and
quarry machines consists in high-quality regular maintenance and repair. The most informative
parameters to estimate the condition of a mining machine transmission are the value and type of the
acoustic emission signal [3,13]. A particular usage of this information widens possibilities of the
existing non-destructive inspection methods and results in emergency failures prevention, the rational
forces and media distribution by technical maintenance and repair. It is experimentally confirmed that
changes in the acoustic emission value reflect the friction processes in a contacting pair, and according
to this value the type of friction can be estimated. As a result of the research, we have confirmed the
possibility to evaluate the working surfaces condition of the interacting transmission elements, to
control the surface wear, to estimate the workability of the entire assembly or a separate kinematic pair
without disassembling the gearbox. Hereby the adequacy of the received information seems to be
enough to make a particular decision [2,5].
References
[1] Artemyev A A To a question of assessment of a resource of elements of transmissions of
mining machines: the scientific publication Mining Equipm. and Electromecan. 9 31-35
[2] Fedorov D V, Potapenko V S 2006 Analysis and Trends in the Development of Acoustic-
Emission Diagnostic Systems for Bearing Units Transp. Ural. 3 15-19
MEACS2018
IOP Conf. Series: Materials Science and Engineering 560 (2019) 012068
IOP Publishing
doi:10.1088/1757-899X/560/1/012068
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[3] Knyazkina V I, Ivanov S L 2017 Experimental measurements of the magnitude of the acoustic
and emission signal for assessing the state of transmission of mining machines Proc. of the
13th Int. Conf. on Mining, Constr. and Energy "Socio-Economic and Environm. Probl. of
Mining, Construction and Energy" (Tula) vol 1 (Tula: State University) 140-144
[4] Knyazkina V I, Safronchuk K A, Ivanov S L 2018 About the possibility of rapid assessment of
the technological condition of mining equipment by the magnitude of the acoustic emission
signal of friction Actual Probl. of Improv. the Efficiency and Safety of Operating Mining and
Oilfield Equipment: Mater. of the V Int. Sci. And Pract. Conf. "Mining And Petroleum
Electromechanics (Perm) (Perm: Perm National Research Polytechnic University) 39-471
[5] Kuzmin A N, Filippov S Yu 2008 Acoustic emission testing of load-lifting mechanisms In the
World of Non-Destructive Testing 2 46-48
[6] Marlin S A, Potapenko V S 2001 Ultrasonic acoustic emission diagnostics of bearing
assemblies: scientific publication In the World of Non-Destruction Control 2 62-63
[7] Maznev A S, Fedorov D V and Potapenko V S 2005 A device for automatic voltage control on
battery banks Lokomotiv 12 27
[8] Nosov V V 2015 Assessment of the impact hazard of a section of a rock massif according to the
results of the registration of its seismic-acoustic activity Notes of the Mining Institute
[Zapiski Gornogo Instituta – in Russian] 216 62-75
[9] Nosov V V and Kotov Yu V 2001 Developing Algorithms for Estimating Strength on the Base
of Imitating Structural Model of Acoustic Emission.I. Effect of Instability of Acoustic-
Emission Coefficient Russian J. of Nondestruct. Testing 37(9) 644-649
[10] Nosov V V and Eltchaninov G S 2011 The Effect of Strength State Nonuniformity on the
Acoustic Emission of Structural Materials Russian J. of Nondestruct. Testing 47(12) 824-833
[11] Nosov V V 2016 Diagnostics of machines and equipment (SPb: “Lan” publishing house) p. 376
[12] Poddubnaya A A 2008 Evaluation of lubricity of transmission oils of mining machines Notes of
the Mining Institute [Zapiski Gornogo Instituta – in Russian] 178 86-90
[13] Gongtian S and Wu Z 2010 Study on Spectrum of Acoustic Emission Signals of Bridge Crane
Insight: Non-Destruct. Test. and Cond. Monit. 52(3) 144-147
