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Formation mechanisms of maximal loads on cutters and cutting heads of coal mining machines

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Category: Content №5 2021

Last Updated on 29 October 2021

Published on 30 November -0001

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Authors:

Yu.N.Linnik, orcid.org/0000-0003-3968-0026, Federal State Educational Institution of Higher Education State University of Management, Moscow, Russian Federation, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

V.Yu.Linnik, orcid.org/0000-0001-5130-8222, Federal State Educational Institution of Higher Education State University of Management, Moscow, Russian Federation, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

S.A.Prokopenko, orcid.org/0000-0002-0141-5377, National Research Tomsk Polytechnic University, Kemerovo, Russian Federation, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

A.Zich, orcid.org/0000-0002-8171-0375, MS QF GmbH, Oderwitz, Federal Republic of Germany

повний текст / full article

Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu. 2021, (5): 043 - 048

https://doi.org/10.33271/nvngu/2021-5/043

Abstract:

Purpose. To determine an influence exerted by the cutting mode and by geometry of cutters on the impact loads in various scenarios of cuttersolid inclusion interaction.

Methodology. Mathematical simulation, statistical analysis

Findings. Fracture of coal seams of a complex structure which contain solid discontinuities (solid inclusions and hard dirt bands) is associated with generation of impact loads on cutters and cutting heads of mining machines which cause a decrease in the productivity of the coal extraction process and premature failure of their components and elements. This impairs efficiency of coal cutting and causes premature failure of different components and parts. It is found that when a cutter cuts an inclusion or touches it, the size of the inclusion has no influence on the value of the peak load. On the contrary, in case of tear-out of an inclusion, the peak cutting force value essentially depends on the size and shape of the inclusion, as well as on the brittleness and plasticity of coal as these properties govern coal-inclusion cohesion. It is found that out of all modes of cutter-solid inclusion interaction, the highest loads arise in the mode of central cutting of inclusions. The mechanisms and behavior of occurrence of loads in short-term cutting of large (unbroken) solid inclusions by a group of cutters are discussed. The maximal loads on groups of cutters on cutting heads can also arise in gradual stalling when the average loading level approaches the tractive effort torque of electric motor when a group of cutters cuts many solid inclusions simultaneously, or in undermining of roof rocks, or in cutting hard dirt bands.

Originality. The probabilities of solid inclusion cutting by a cutter are determined for different outputs of a cutting head, and the action times of the maximal peak load in cutting a coal strip 100 m long are assessed. The relations are proposed to calculate the levels and action times of maximal loads on a group of cutters in cutting solid inclusions, as well as the coefficients of variation in the loads and the loading inequality of a cutting head.

Practical value. The results obtained by the authors should be taken as a basis in determination of the maximal instantaneous torque in the cutting head transmission to be used later on in calculation of the long-term strength of the transmission components.

Keywords: coal, cutter, cutting head, coal mining machine, solid inclusions, cutting force, cuttability

References.

1. Zich, A., Linnik, Yu.N., & Linnik, V.Yu. (2015). Selecting parameters of cutter-loader drums for specific operating conditions. GeoResources Journal Germany, (2), 40-45.

2. Prokopenko, S.A., Ludzish, V.S., & Kurzina, I.A. (2017). Design of New-Class Picks for CutterLoaders. Gornyi Zhurnal, (2), 75-78.

3. Mametyev, L.E., Khoreshok, A.A., Tsekhin, A.M., & Borisov,A.Y. (2019). Research of interaction of the cutting tool with the coal massif. Mining Equipment and Electromechanics. https://doi.org/10.26730/1816-4528-2018-6-34-39.

4. Zakharov, Y.N., & Shcherba, T.P. (2014). Study of the effectiveness of a cutting drum of a shearer. Mining informational and analytical bulletin (scientific and technical journal), (2), 43-48.

5. Chunming Shen, Baiquan Lin, Fanwei Meng, Qizhi Zhang, & Cheng Zhai (2012). Application of pressure relief and permeability increased by slotting a coal seam with a rotary type cutter working across rock layers. International Journal of Mining Science and Technology, 22(4), 533-538. https://doi.org/10.1016/j.ijmst.2012.01.016.

6. Kumar, C., Murthy, V.M.S.R., Kumaraswamidhas, L.A., & Prakash, A. (2018). Design Methodology for Cutting Drum, Power Rating and Operational Control of Surface Miner under Varied Rock Conditions An Approach. Journal of Mining Science, (4), 582590. https://doi.org/10.1134/S106273911804404X.

7. Gerike, B.L., Klishin, V.I., & Gerike, P.B. (2016). A new index of rock-breaking tool efficiency. Journal of Mining Science, (52), 481-486. https://doi.org/10.1134/S1062739116030682.

8. Khoreshok, A.A., Mametiev, L.E., Tsekhin, A.M., & Borisov,A.Yu. (2012). Underground Mining Machines and Equipment. In Cutting Tools: Educational Aid, Kemerovo: KuzGTU.

9. Aksenov, V.V., & Khoreshok, A.A. (2014). Determination Procedure of Cutting Tool Parameters: Review and Discussion. In Energy Safety of Russia. New Approaches to Advancement in Coal Industry: XVI Conference Proceedings, (pp. 9294). Kemerovo: Inst. Uglya SO RAN, 92-94.

10. Gorbatov, P.A. (Ed.) (2011). Prediction of Maximal Loads in Systems of Shearer Cutting Drum Drives. Donetsk: DonNTU UNITEKH.

11. Yao, Q., Li, X., Sun, B., Ju, M., Chen, T., Zhou, J., & Qu, Q. (2017). Numerical investigation of the effects of coal seam dip angle on coal wall stability. International Journal of Rock Mechanics and Mining Sciences, 100, 298-309. https://doi.org/10.1016/j.ijrmms.2017.10.002.

12. Schwartzkopff, A.K., Melkoumian, N.S., & Xu, C. (2017). Fracture mechanics approximation to predict the breakdown pressure using the theory of critical distances. International Journal of Rock Mechanics and Mining Sciences, 95, 48-61. https://doi.org/10.1016/j.ijrmms.2017.03.006.

13. Stoxreiter, T., Martin, A., Teza, D., & Galler, R. (2018). Hard rock cutting with high pressure jets in various ambient pressure regimes. International Journal of Rock Mechanics and Mining Sciences, 108, 179-188. https://doi.org/10.1016/j.ijrmms.2018.06.007.

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