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A life cycle of mining machines includes, among others, such processes as:

  • an installation of a machine in the working or its relocation to another working (e.g. equipping or disassembly of longwall faces),
  • planned exchange of assemblies or components,
  • damage repairs,
  • maintenance services,
  • a removal of a machine.

These processes are performed in the conditions which differ significantly from those at producers’ site. The factors impeding a realization of these processes include: confined working space, inclined and slippery floor, insufficient lighting, lack of lifting and hoisting equipment, used in the in-house transport. Besides, during assembly and disassembly activities it is indispensable to operate components of large overall dimensions and of big weights in confined working space. These activities require awkward body postures of operators and their significant physical effort.

The first assembly of a machine at the producer’s site does not reveal all the difficulties, which can be experienced at work underground such as a limited access to some areas, an insufficient field of vision, lack of possibility to get appropriate forces due to a limitation of range of limbs motion and impeded use of tools.

Limitations and impediments in a realization of maintenance and repair processes can be identified with virtual prototyping methods at the design stage of machines. To achieve this objective a virtual work environment, consisting of computer models of material objects (machines and equipment) and of models of human anthropometric features should be created. Computer simulations of activities, performed during surveys and repairs are created and assessed in the environment, which is shown in the photos below.

Activities performed:

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a) in a factory
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b) underground

 

Scenarios of technical and technological development of
the hard coal mining industry

A realization of the foresight project entitled: “Scenarios of technical and technological development of the hard coal mining industry”, financed by the European Union and the Ministry of Science and Higher Education, within Action 1.4 of the Sectoral Operational Programme  - Increase of Competitiveness of Enterprises, years 2004 – 2006, started on 1st July 2006. Strengthening a collaboration between the research and development sector and the economy.

The project will be finished on 30th June 2008. It is coordinated by the GIG – Central Mining Institute in Katowice.
Its participants are as follows:

  • AGH University of Science and Technology in Cracow,
  • Mineral and Energy Economy Research Institute in Cracow,
  • Silesian University of Technology in Gliwice,
  • EMAG Automation and Safety Systems in Katowice,
  • KOMAG Mining Mechanization Centre in Gliwice.

The project objective is a determination of scenarios of a technical and technological development as well as functioning of the hard coal mining industry in the condition of sustainable development. The technologies of hard coal winning and processing as well as forecasts of their development trends till the year 2020 will be monitored.

The project assumptions include:

  • a demand of Poland, European Union and other markets for raw materials till the year 2020,
  • hard coal resources according to the present and forecasted assessments,
  • conditions of the sustainable development of the minerals winning industry until the year 2020,
  • present technical and technological conditions of hard coal winning and processing industry,
  • competitiveness of foreign producers.

One of the project results will be a creation of the data bank about selected technologies, possibilities of their development and about their effectiveness as well as about personal data of expert groups. The final stage of the project will include a preparation of a report, containing among others:

  • a description of scenarios of hard coal mining technologies,
  • presentations of monitoring principles of hard coal mining technologies development, a periodic verification of developed scenarios,
  • suggestions of communication forms with decision-makers to transfer information about the results of the verification procedures.

Present conditions in the mining sector, such as production concentration, increase quality, reliability and functionality requirements. At the same time a phase of experimental operation of a material prototype in in-situ conditions gets reduced. Some limitations connected with testing material prototypes of mining machines impose a necessity of searching new prototyping methods. One of them is a method of creating virtual prototypes of mining machines, which enables to test future technical means at the early designing stage.

Virtual prototyping is a process of creating and testing virtual prototypes. It starts from a construction of geometric models of products, which are then used for conducting a computer simulation, which is shown below. Virtual prototyping includes processes of designing, production, maintenance as well as recycling. A virtual prototype is a set of criterial models of the same technical means. Criterial models are created for anticipated criterial conditions. Criterial conditions, in the strength aspects, include selected critical sets of loads or supports. An identification of criterial conditions is performed both during an operation as well as on a test rig. Within this particular research project virtual prototypes have been subjected to a verification in the following aspects: strength, functional and ergonomic.

An operation of virtual prototypes has been tested, among others, using the Finite Elements Method (FEM), the software for an analysis of kinematics and dynamics of mutli-body systems (MBS), reverse-engineering designing method (RE) and the software for a visualisation and analyses of anthropotechnical systems. A method of constructing virtual prototypes includes guidelines for a creation of analytical models of mining machines, with particular attention paid to their future validation. A verification of criterial models of a virtual prototype has been performed on a test rig available at the KOMAG Centre.

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Exemplary analyses of a virtual prototype of a longwall shield support
 

The subject of the research project includes a development of a method of a hoisting machine pulley design, using strength analyses, based on the Finite Elements Method (FEM) and dynamic analyses, using a mathematical model, describing a mine shaft hoist.

The developed mathematical models, describing dynamics of a shaft hoist, will be used for a determination of loads, changeable in time, which will become boundary conditions in the strength analysis conducted with the Finite Elements Method (FEM).

At present the Finite Elements Method is commonly used for strength analyses of hoisting machine components, in particular of a pulley. The analytical methods, used up to the present time, for determining the boundary conditions of loads in a pulley strength analysis are simplified to a significant extent and thus inaccurate. Traditional methods of determining loads omit several, essential parameters connected with operational dynamics of a mine shaft hoist such as: a hoist operational speed, a position of conveyances, elasticity of hoisting and balance ropes. These dynamic parameters are considered in the mathematical modelling process of a mine shaft hoist. Basing on such models it is possible to determine a character of changes and values of loads during an operation of a hoisting machine in a significantly more accurate manner than in the case of traditional analytical methods, which enables to conduct a more accurate strength analysis of hoisting machine components, in particular of a pulley.

Intensive cooling system of shearer ranging arms of high power with an installation of forced lubrication of gears

An intensive cooling system of shearer ranging arms of high power with an installation of forced lubrication of gears is a result of a research and development project, realized together with the Zabrzanskie Mechanical Works, Joint Stock Company (Zabrzańskie Zakłady Mechaniczne S.A.) within the framework of the Targeted Project No 6ZR8 2005 C/06 664, supported by the Ministry of Education and Science. An installation of this cooling system requires a significant modification of the R500 ranging arm, in particular as regards a lubrication and water installations. After an adaptation, this system can be applied to other types of shearer ranging arms, equipped with an installation of forced lubrication, a water installation and having sufficient space in the ranging arm frame for installing coolers. Both installations form a joint water and lubricating system.

Laboratory tests of the research model of the R500 ranging arm will enable to assess an effectiveness of cooling the gear oil, using the coolers of the intensive cooling system.

An intensive cooling system of shearer ranging arms of high power will improve lubricating conditions of gears and bearing pairs, having a direct impact onto increasing both the operational life of the gear oil as well as the operational life of shearer ranging arms.

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