Analytical study of the velocity of the lubricating fluid in the hydrodynamic journal bearing with the effect of centrifugal force for short bearing type

Keywords: centrifugal force of the lubricating fluid, short bearing, floating ring bearing, velocity of lubricant, analytical method, hydrodynamic journal bearings

Abstract

The paper aims to obtain the expression of the velocity of lubricating fluid in the hydrodynamic journal bearings by analytical method. In the classical short-bearing theory, the fluid flow was studied by ignoring the effect of centrifugal force of the lubricating fluid film. However, the self-oscillation of the shaft of high-power motors does not follow the rules in classical hydrodynamic lubrication theory. To explain this phenomenon, a modified form of Reynolds equation, in which the influence of centrifugal force of the lubricant is not ignored, is established. The study aims to establish the modified Reynolds equation by including the effect of centrifugal forces for the case of the short bearing type. Integration of the Navier-Stokes equations, yield the expressions for the components of velocity of the lubricating fluid in the gap. The oil’s pressure in the hydrodynamic journal bearing is obtained by solving the modified Reynolds equation. The numerical results are considered in the case of the stable equilibrium position of the motion of the shaft, i.e. the symmetry axis of the shaft does not move. The plots of the velocity components in the tangential axial direction are displayed too. The theoretical results of a parabolic velocity distribution similar to that of a Newtonian fluid, derived from a Bingham plastic flow model. The flow in the gap, which are obtained by analytical method, are completely consistent with its boundary conditions and its physical properties. Further, with these results, the paper as a lemma to solve the dynamics problem in floating ring bearing with the influence of the centrifugal force of the lubricant

Downloads

Download data is not yet available.

Author Biography

Nguyen Van Thang, Hanoi University of Industry

Department of Mechanical Engineering 

References

Loytsyanskiy, L. G. (1987). Mekhanika zhidkosti i gaza. Moscow: Nauka, 823. Available at: https://www.rfbr.ru/rffi/ru/books/o_26855#1

Hori, Y. (2002). Hydrodynamic Lubrication. Springer Tokyo, 231. doi: https://doi.org/10.1007/4-431-27901-6

Belyaev, A. K., Krommer, M., Irschik, H., Nguyen, V. T. (2008). Forces and moments acting on the rapidly rotating floating bearing. XXXVI International Summer School-Conference “Advanced Problems in Mechanics”, 104–111.

Nguyen, V. T. (2011). Sily i momenty, deystvuyuschie na rotor v upornom podshipnike skol'zheniya, s uchetom gidrodinamiki smazki i tsentrobezhnykh sil. Nauchno-tekhnicheskie vedomosti Sankt-Peterburgskogo gosudarstvennogo politekhnicheskogo universiteta. Fiziko-matematicheskie nauki, 1, 116–122. Available at: https://cyberleninka.ru/article/n/sily-i-momenty-deystvuyuschie-na-rotor-v-upornom-podshipnike-skolzheniya-s-uchetom-gidrodinamiki-smazki-i-tsentrobezhnyh-sil

Tondl, A. (1971). Dinamika rotorov turbogeneratorov. Leningrad: Energiya, 387.

Boyaci, A., Hetzler, H., Seemann, W., Proppe, C., Wauer, J. (2008). Analytical bifurcation analysis of a rotor supported by floating ring bearings. Nonlinear Dynamics, 57 (4), 497–507. doi: https://doi.org/10.1007/s11071-008-9403-x

Dubois, G. B. (1953). Analytical derivation and experimental evaluation of short-bearing approximation for full journal bearing. Report 1157. Available at: https://digital.library.unt.edu/ark:/67531/metadc60530/m1/1/

Hatakenaka, K., Tanaka, M., Suzuki, K. (2002). A Theoretical Analysis of Floating Bush Journal Bearing With Axial Oil Film Rupture Being Considered. Journal of Tribology, 124 (3), 494–505. doi: https://doi.org/10.1115/1.1454104

Kirk, R. G., Alsaeed, A. A., Gunter, E. J. (2007). Stability Analysis of a High-Speed Automotive Turbocharger. Tribology Transactions, 50 (3), 427–434. doi: https://doi.org/10.1080/10402000701476908

Li, C.-H. (1982). Dynamics of Rotor Bearing Systems Supported by Floating Ring Bearings. Journal of Lubrication Technology, 104 (4), 469–476. doi: https://doi.org/10.1115/1.3253258

Mutuli, S., Bonneau, D., Frene, J. (1986). Velocity Measurements in the Grease-Lubricating Film of a Sliding Contact. A S L E Transactions, 29 (4), 515–522. doi: https://doi.org/10.1080/05698198608981715

Li, J. X., Höglund, E., Westerberg, L. G., Green, T. M., Lundström, T. S., Lugt, P. M., Baart, P. (2012). μPIV measurement of grease velocity profiles in channels with two different types of flow restrictions. Tribology International, 54, 94–99. doi: https://doi.org/10.1016/j.triboint.2012.03.007

Guo, H., Xia, B. Q., Cen, S. Q. (2011). Performance Analysis of High Speed Floating Ring Hybrid Bearing in the Laminar and Turbulent Regimes. Advanced Materials Research, 197-198, 1776–1780. doi: https://doi.org/10.4028/www.scientific.net/amr.197-198.1776


👁 64
⬇ 79
Published
2022-07-30
How to Cite
Thang, N. V. (2022). Analytical study of the velocity of the lubricating fluid in the hydrodynamic journal bearing with the effect of centrifugal force for short bearing type. EUREKA: Physics and Engineering, (4), 93-100. https://doi.org/10.21303/2461-4262.2022.001962
Section
Engineering