DYNAMIC LOADS INFLUENCING ON ELEMENTS OF MULTI-MOTOR HYDRAULIC DRIVE OF CCM COOLER

Based on dynamic model of multi-motor drive of continuous casting machine (CCM) coolers, mathematical model is formed andevaluation of low- frequency dynamic processes occurring in the drive is performed. Model of the coolers drive is an eight-mass dynamic system with elastic connections between masses. Description of links takes into account presence of gaps and damping properties in them. Active load in dynamic model is described by mechanical characteristic of hydraulic drive. The cooler moving beams and cooling metal mass are regarded as reactive loads. Motion of all masses of the model is described through the system of second-order differential equations. Integration of differential equations was carried out by Runge-Kutta method. To analyze influence of various­ factors on loads that arise in cooler drive, a software program was written. Evaluation of dynamic processes in the CCM cooler drive shows that dynamic component of load in the elements of machine for vertical displacement of mobile beams is of a significant value. Dynamic response factor K_d in the drive elements reaches 2.2  –  2.3. Analysis of the factors influencing dynamic processes in the cooler drive reveals that the optimum ratio of masses of metal located in cooler and moving beams of the cooler is close to 1.6  –  1.7. The minimum dynamic coefficient is close to 1.5. The nature of change in drive dynamics due to viscosity of working fluid of hydraulic drive is smoothly decreasing linear dependence with a minimum corresponding to fluid viscosity value of 4·10–5   m2/s. Speed of vertical displacement of the moving beams of the coolers also affects dynamic processes that arise in their drive. At the same time, the dynamic response factor is higher with the higher speed. Within the limits of change in speed of movement of the moving beams of the cooler referred to in the paper, K_d varies from 2 to 2.2. Dynamic model of multi-motor hydraulic drive of cooler of a walking-type used in the work makes it possible to analyze low-frequency dynamic processes occurring in hydraulic drive. As a result, it be comes possible to identify degree of influence of various design and power conditions of operation of hydraulic drive on low-frequency oscillations in it and, to develop optimal design solutions in terms of its operability using calculating tool.

1. Spivakovskii A.O., D’yachkov V.K. Transportiruyushchie mashiny: Uchebn. posobie dlya mashinostroitel’nykh vuzov [Transporting machines: Manual for machine-building universities]. Moscow: Mashinostroenie, 1983, 487 p. (In Russ.).

2. Savel’ev A.N., Kozlov S.V. Estimation of operational reliability of the CCM cooler with hydraulic drive. In: Materialy shestnadtsatoi nauchno-prakticheskoi konferentsii po problemam mekhaniki i mashinostroeniya [Materials of 16th Sci.-Pract, Conf. on Problems of Mechanics and Mechanical Engineering]. Novokuznetsk: Sib-GIU, 2006, pp. 152–159. (In Russ.).

3. Frolov K.V. Modern Problems of Vibrations in the Systems “Man-machine-Environment”. Studies in Environmental Science. 1981, vol. 13, pp. 1–41.

4. Frolov K.V. Metody sovershenstvovaniya mashin i sovremennye problemy mashinostroeniya. Osnovy proektirovaniya mashin [Me­ thods of improving machines and modern problems of mechanical engineering. Basics of machine design]. Moscow: Mashinostroenie, 1984, 224 p. (In Russ.).

5. Il’in M.M., Kolesnikov K.S., Saratov Yu. Teoriya kolebanii. Uchebnik dlya vuzov [Theory of oscillations. Textbook for universities]. Moscow: Izd-vo MGTU im. N.E. Baumana, 2003, 271 p. (In Russ.).

6. Savel’ev A.N., Stupakov M.I. Opredelenie dinamicheskikh nagruzok v tekhnologicheskom oborudovanii. Uchebn. posobie [Determination of dynamic loads in process equipment. Manual]. Novokuznetsk: SibGIU, 1999, 32 p. (In Russ.).

7. Savel’ev A.N., Stupakov M.I., Savel’ev N.V. Dinamika tyazhelonagruzhennykh tekhnologicheskikh mashin. Uchebn. posobie [Dynamics of heavy-duty technological machines. Manual]. Novokuznetsk: SibGIU, 2005, 190 p. (In Russ.).

8. Savel’ev A.N., Kozlov S.V., Anisimov D.O. Features of formation of dynamic models of multi-motor hydraulic drives of CCM coolers. Vestnik Sibirskogo gosudarstvennogo industrial’nogo universiteta. 2016, no. 2 (16), pp. 28–31. (In Russ.).

9. Savel’ev A.N. Teoriya rabotosposobnosti tekhnologicheskikh ma­ shin [The theory of working capacity of technological machines]. Kemerovo: Kuzbassvuzizdat, 2008, 225 p. (In Russ.).

10. Shabana A.A. Dynamics of Multibody Systems. Cambridge: Cambridge University Press, 2005.

11. Astashev V.K., Babitskii V.I., Vul’fson I.I. Dinamika mashin i upravlenie mashinami: spravochnik [Dynamics of machines and machine control: Reference book]. Kreinin G.V. ed. Moscow: Mashinostroenie, 1988, 239 p. (In Russ.).

12. Eich-Soellner E., Fuehrer C. Numerical Methods in Multibody Dynamics. Stuttgart: Teubner, 1998.

13. Amirouche F. Fundamentals of Multibody Dynamics. Boston: Birkhäuser, 2006.

14. Trubetskov D.I., Rozhnev A.G. Lineinye kolebaniya i volny: Uchebnoe posobie dlya vuzov [Linear oscillations and waves: Manual for universities]. Moscow: Izd-vo fiziko-matematicheskoi literatury, 2001, 416 p. (In Russ.).

15. Bashta T.M., Rudnev S.S., Nekrasov B.B. etc. Gidravlika, gidromashiny i gidroprivody. Uchebnik dlya mashinostroitel’nykh vuzov [Hydraulics, hydraulic machines and hydraulic drives. Textbook for machine-building universities]. Moscow: Mashinostroenie, 1982, 423 p. (In Russ.).

16. Chuprakov Yu.I. Gidroprivod i sredstva gidroavtomatiki [Hydraulic drive and hydroautomatics]. Moscow: Mashinostroenie, 1979, 232  p. (In Russ.).

17. Schiehlen W. ed. Multibody Systems Handbook. Berlin: Springer, 1990.

18. Stoer J,. Bulirsch R. Numerische Mathematik 2,4 Auflage. Berlin: Springer, 2000.

19. Nayfey A.H., Balachandran B. Aplied Nonlinear Dynamics. New York: Wiley 1995.

20. Vvedenie v teoriyu mekhanicheskikh kolebanii: Ucheb. posob. dlya vtuzov [Introduction to the theory of mechanical oscillations: Manual for technical colleges]. Panovko Ya.G. Moscow: Nauka, 1991, 255 p. (In Russ.).