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Heavy operating conditions of mining machines as well as the high level of dynamic loads lead to reduction of their service life. The quantitative estimation of the machine reliability by one of the feature – service life – has become widely distributed in all the branches of engineering. Technical diagnosis is one of the important methods of impro...
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Citations
... Consequently, it is possible to effectively describe the fault type and to achieve strong operability in the systems. Monitoring the belt conveyor drive motor electrical parameters [18] or the reductors [19] can also serve as a basis for predictive diagnostics to detect anomalies and possible defects, so it is possible to fix them before they result in a failure. ...
Together with the research and development of belt conveyors, diagnostic methods for their reliable operation have been developed. Our research is focused on the development of a diagnostic system and method of sensing the magnetic markers implemented directly into the conveyor belt, as in this way, it is possible to determine the velocity of the conveyor belt, which can be a source of information about the potential malfunction of the drive unit, control system, or of the belt itself. The magnetic markers can be also used to mark the particular segments of the conveyor belt, which can significantly enhance maintenance procedures thanks to the identification of damaged segments and the possibility to stop the conveyor belt in the maintenance area. However, problems can occur with the implementation of the magnetic markers. To prevent the magnetic markers from falling out, FEM (finite element method) simulations and analyses of commercially available magnetic markers with different dimensions were performed to analyze the nominal and friction force and related average contact pressure acting on the magnetic markers implemented into holes drilled into the conveyor belt in the curved state when passing through the drum.
... Since rock and coal transportation are organized as separate traffic flows, which have only one thing in common -excavation and loading equipment, then calculation of indicators for these traffic flows is performed separately. The situation is the same for both surface and underground mining [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][21][22][23][24][25][26][27][28][29], as well as for various geo-environmental issues where consideration of cargo flows of different genesis is required [32,33,[35][36][37][38][39][40]. ...
The study of the technology of excavation and loading operations at more than 15 open pit mines of Kuzbass with the use of trucks shows the general similarity of the technological process in terms of providing transport operations of haul trucks: loading is often carried out at the level of excavator standing, less often – below the level of excavator standing. The predominant scheme of haulage haul truck approach for loading – dead-end, less often – circular, very seldom – through. When digging trenches and working narrow strips, it is difficult to approach excavators due to insufficient width of the site for turning, the necessity of safety and barrier shafts, etc. In this case, the maneuvering time of the haul trucks and their exchange time for loading depends considerably on the skills of the haul truck driver. Considering that the mining operations at the open-pit mines are gradually going deeper and deeper, there is no reason to assume that the width of the vehicle turning sites will increase in the future. Therefore, the use of autonomous heavy platforms, which do not require turning during their delivery for loading, seems very promising in the so-called cramped working conditions. In this work the question of working time losses at haul trucks exchange at loading in real conditions is briefly considered, dependence of average speed of movement and time of trip on a distance of transportation is resulted.
... All organizational tasks in mining [1][2][3][4][5][6][7][8][9][10][11][12][13] (open-cut mining in general) are subdivided into planned (prescheduled, scheduled for implementation) and unplanned (to eliminate violations of the technological process and the resulting unscheduled downtime of equipment) [14][15][16][17][18][19][20][21]. Unplanned downtime of excavators account for 20-50% of the calendar time [22][23][24], and 30-50% of unscheduled downtime refers directly to the process of excavation and loading [25][26][27][28]. ...
Automobile transport currently dominates the transportation of overburden and coal at open pit mines. Its share has been steadily growing since the 1970s. This is due to objective reasons, first of all, a rather limited area of application of railway transport: a significant transport distance, a large cargo traffic and a small depth of the quarry. First of all, it concerned the depth of open-cut mines, because when deepening the quarry for one trench it was necessary to extract considerable volumes of overburden to provide accommodation of transport berms because of the big radius of curvature of a railway track, which reached 200 m. Therefore, given the fact that open-pit mining went to a greater depth at almost all enterprises, there was a widespread abandonment of rail transport for intra-pit transportation in favor of automobile transport. For various reasons, a fairly economical and promising mode of transport – conveyor transport – has not become widespread at Kuzbass coal mines. Not least of all, this is due to climatic conditions, as well as the complexity of mining and geological conditions of the Kuznetsk Basin, which are among the most complicated in the world. Suffice it to say that more than 80% of coal seams have a complex or very complex structure. Therefore, the problem of research and description of the key characteristics in open-pit mining is very urgent.
... It is known that maximum excavator output is achieved with lower digging and lower haul truck standing; however, there are certain mining and technical conditions in which such an arrangement of the haul truck relative to the excavator is not possible. Such a problem does not exist at underground mining [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. Therefore, it is necessary to use other, less profitable in terms of output, variants of positioning of excavation and transport equipment [26][27][28][29][30][31]. ...
When studying the influence of excavator bucket capacity on haul truck loading time, it is necessary to assess the technical and economic performance of the complex. If the cost of the machine shift of the complex will not cover the increase in productivity, then it is inexpedient to use this complex. This issue requires further, more detailed study and performance of detailed technical and economic analysis. Also, it is necessary to consider classical recommendations about ratio of excavator bucket capacity and haul truck body. It should be noted that at present, there is a significant divergence in the size range of excavators: powerful, with a large capacity bucket, rope shovels are used for mining the coalless zone; small maneuverable hydraulic shovels – for mining the coal-bearing zone. In this paper, we will try to combine the first and the second: consider hydraulic excavators with maximum bucket capacity, which is reasonable to use when mining overburden. In addition, a detailed study of the options of mutual arrangement of excavator and haul truck has not been performed until recently, this work is intended to fill this gap.
... Причиной аварийных отказов конических (угловых) редукторов, используемых в приводах хода ШСВ, является разрушение зубьев ведущей и ведомой шестерен. По информации, полученной от персонала сервисных служб, конические редукторы требуют сложных и постоянных регулировочных работ при монтаже и в процессе эксплуатации [8,14]. ...
Statistical data on the reliability of self-propelled mine cars (SPMC), operating in the potassium mines of the Verkhnekamskoye potassium and magnesium salts deposit are analyzed. Identified the main nodes that limit the resource SPMC. It has been proven that the most common failures of self-propelled cars are the failure of wheel hubs, bevel gears and traveling electric motors. The analysis of the system of maintenance and repair of mine self-propelled cars. It is indicated that the planning and preventive system of SPMC repairs is characterized by low efficiency and high material costs: car maintenance is often carried out upon the occurrence of a failure, which leads to prolonged downtime not only of a specific haul truck, but of the entire mining complex. A method for assessing the technical condition of the electromechanical part of a mine self-propelled car by the nature of power consumption is proposed. This method allows you to control the loading of the drives of the mine self-propelled car, as well as to assess the technical condition of the drives of the delivery machines in real time.
Upon expiration of the standard service life of a mine propelled car specified in the operational documentation, its further operation is prohibited and the car is subject to industrial safety expertise. As part of the examination, it is necessary to determine the operating time and calculate the service life of a mine self-propelled car outside the regulatory period. A method has been developed for determining the residual service life of mine car on the basis of instrumentation control data in the conditions of potash mines.
... На участке L II комбайн работает с возрастающими остановками, обусловленными загрузкой вагона. На участке L III комбайн простаивает в ожидании ШСВ и во время его загрузки [6,7]. ...
Quarry automobile transport is most important in the transportation of overburden and coal in open-cast mining operations. In this article, based on the existing analysis of the use of classic haul trucks, the change in their output is determined by some influencing factors: the type of loading of the rock mass and the bucket capacity of the excavator used. It is taken into account that when loading an unmanned dump truck, there is no need to maneuver the vehicle, which increases output, especially with a small haulage arm. Some output calculation results are given and areas for further research are identified.
The article presents the method of controlled modification of engine oil, as well as the results of operational studies to assess the service life of heavy-duty vehicle engines. The method of controlled modification of engine oil includes a system of five levels of information helping to assess the technical condition of engines of heavy-duty vehicles, including mining dump trucks. The first level of the methodology includes the use of subjective methods for determining the technical condition of engines by its external manifestations. The second level of the methodology includes the use of simple instrumental methods and means of obtaining diagnostic information about the technical condition of the engine and its subsystems. The third level of the technique involves the use of a drip test of engine oil. The fourth level of the methodology includes the chemical analysis of engine oil samples. The fifth level of the technique involves spectral analysis of engine oil to determine the presence of metals.
The justification of the linear displacement sensors installation in mine workings is described in this paper. The required technical characteristics of the sensors are given. The main types of primary linear displacement converters are presented. The choice of inductive solenoid-type converters and sensors based on linear differential transformers (LVDT) is justified. The advantages and disadvantages of inductive transducers, their accuracy and measurement limits are described, and measuring methods of inductance of the solenoid-type transducers and the converter output signal based on LVDT are considered. The results of sensors experimental studies based on the solenoid-type inductive transducers are presented.
The article discusses ways to reduce energy consumption in the open-pit mining of minerals in the conditions of Kuzbass by reducing the sticking to the working automobile equipment and excavator complexes. When excavating and transporting cohesive rocks, due to a sharp change in climatic conditions, adhesion-cryogenic processes occur (sticking, freezing on excavator buckets, dumpcars, conveyor belts, dump truck bodies, etc.). This significantly reduces the efficiency of excavating and transport complexes. In this paper, we consider the adhesion-cryogenic processes affecting the rock, methods of anti-sticking for the selection of optimal solutions.
