NUST MISIS, Moscow, Russia:
I. N. Klementieva, Senior Lecturer, Candidate of Engineering Sciences
D. A. Kuziev, Associate Professor, Candidate of Engineering Sciences, da.kuziev@misis.ru

One of the critical objectives set by the long-term program of the coal industry development up to 2030, approved by the Government of the Russian Federation is coal extraction by the most effective open pit mining method using draglines. Traction of draglines is composed of a drive winch and rope transmissions. Digging (excavation) duration makes up to 30 % of the total operating cycle of a dragline. During digging, the traction, drive, gears and rope transmissions of a dragline are exposed to considerable dynamic loads. Deloading of the dragline traction is achievable through the use of an elastically damping device inserted in the rope transmission. With longer duration of the bucket performance, the force in the drag cables grows consequent on the increase in the digging resistance, tangential weight of the filled bucket and in the bucket–rock friction force as a result of the growing mass connected to the drag cables. At the same time, stiffness of the drag cables increases as their length gets shorter. Put it otherwise, the natural frequency in the drag cables–bucket system is a variable value and varies from the moment of the bucket breakaway up to the moment of digging termination. It is shown analytically that the efficient reduction in dynamic loading requires that the natural frequency of the elastic damper mounted in the rope transmission of a dragline is lower than the natural frequency in the rope cables–bucket system at the end of digging.

1. Development Program for the Coal Industry in Russia up to 2030. Approved by the Russian Federation Government Decree No. 1099 dated June 21, 2014 (as amended 05.04.2019). Available at: http://docs.cntd.ru/document/420204008 (accessed: 15.12.2021).
2. Walking dragline excavators. Uralmash. Available at: https://uralmash-kartex.ru//assets/gallery/Ekskavatoryi/Draglajnyi/Драглайны_шагающие.pdf (accessed: 19.12.2020).
3. Belyakov Yu. I., Vladimirov V. M. Improvement of excavation at open pits. Moscow : Nedra, 1974. 303 p.
4. Dombrovskiy N. G., Pankratov S. A. Digging machines. Moscow : Gosstroyizdat, 1961. Part I : Singlebucket excavator. 651 p.
5. Makhno D. E., Shadrin A. I., Avdeev A. N., Makarov A. P. Cold brittleness and cold resistance of metalware in mining machines in the conditions of the North. Irkutsk : Izdatelstvo IrGTU, 2010. 231 p.
6. Fedorov D. I., Bondarovich B. A., Pereponov V. I. Reliability of metal structures in digging machines. Design and evaluation methods. Moscow : Mashinostroenie, 1971. 216 p.
7. Poderni R. Yu. Mechanical equipment of open pits : Tutorial. 8^th edition, revised and enlarged. Moscow : Mining Media Group, 2013. 593 p.
8. Chulkov N. N., Chulkov A. N. Drive design for quarrying machines. Moscow : Mashinostroenie, 1979. 104 p.
9. Gustov Yu. I., Sletov S. Yu. Forecasting of tribomechanical indicators of the system traction rope – KVSh lifts by slip friction coefficient. Lift and Transportation Engineering. 2019. No. 1-2(96). pp. 2–4.
10. Lebedev G. V., Khoroshavina T. A., Yarovikov V. A., Gogelashvili G. Sh., Tselishcheva L. V. Dependence of sliding friction coefficient on different factors. Nauchnomy progressy – tvorchestvo molodykh. 2016. No. 1. pp. 54–57.
11. Solovev S. V., Kuziev D. A. Dragline ESh-10/70 linkage stiffness parameters study. Ugol. 2017. No. 1. pp. 37–38.
12. Solovev S. V., Kuziev D. A. Dependence of strip-mine dragline work process dynamics from elasticdamping parameters of its linkage gear. Ugol. 2014. No. 2. pp. 60–62.
13. Kai Zhang, Guoxi Li, Jing Zhong Gong, Meng Zhang. Research on Assembly Data Mining Technology of Complex Mechanical System. Procedia CIRP. 2016. Vol. 44. pp. 97–101.
14. Zhenjun Li, Xiaomo Yu. Data mining technology for mechanical engineering computer test system. Mechanical Systems and Signal Processing. 2020. Vol. 141. DOI: 10.1016/j.ymssp.2020.106628
15. Biderman V. L. Mechanical vibration theory. 3^rd revised edition. Moscow : URSS, 2017. 416 p.
16. Yang S., Mi X., Wang X., Li D., Liu W., Liu X. A design method of inertial navigation's damping device based on rubber equivalent dynamic Young's Modulus. Zhongguo Guanxing Jishu Xuebao. Journal of Chinese Inertial Technology. 2019. Vol. 27, Iss. 5. pp. 695–700.
17. Kuznetsov N. K., Iov I. A., Iov A. A. Developing electromechanical model of walking dragline traction mechanism. Vestnik Irkutskogo gosudarstvennogo tekhnicheskogo universiteta. 2017. Vol. 21, No. 11(130). pp. 53–66.
18. Heidari H. R., Safarpour P. Design and modeling of a novel active squeeze film damper. Mechanism and Machine Theory. 2016. Vol. 105. pp. 235–243.