Thermohydrodynamic Analysis and Pad Temperature Measurement of Tilting Pad Journal Bearing with Worn Pad

표면이 마모된 틸팅 패드 저널베어링의 열윤활 해석 및 온도 측정

  • Lee, Donghyun (Dept. of System Dynamics, Korea Institute of Machinery and Material) ;
  • Sun, Kyungho (Dept. of System Dynamics, Korea Institute of Machinery and Material) ;
  • Kim, Byungock (Dept. of System Dynamics, Korea Institute of Machinery and Material) ;
  • Kang, Donghyuk (Dept. of System Dynamics, Korea Institute of Machinery and Material)
  • 이동현 (한국기계연구원 시스템다이나믹스 연구실) ;
  • 선경호 (한국기계연구원 시스템다이나믹스 연구실) ;
  • 김병옥 (한국기계연구원 시스템다이나믹스 연구실) ;
  • 강동혁 (한국기계연구원 시스템다이나믹스 연구실)
  • Received : 2017.06.13
  • Accepted : 2017.07.31
  • Published : 2017.08.31


With the increase in adoption of tilting pad journal bearings (TPJBs), various failure mechanisms related to TPJBs have been reported, of which pad wear is a frequently reported one. Pad wear causes change in geometry of the bearing, which can sometimes result in the failure of the entire system. The objective of this research is to investigate the influence of pad wear on the pad temperature, which is one of the widely used condition monitoring methods for TPJBs. For the theoretical investigation, thermohydrodynamic (THD) analysis was conducted by solving the generalized Reynolds equation and the 3D energy equation. The results of the analysis show that the temperature of the loaded pad increases while that of the unloaded pad decreases, when there is wear on the loaded pads. In addition, the minimum film thickness decreases with an increase in the wear depth. A validation test was conducted with a test rig, which mimics the axial turbine when a test rotor is supported by two TPJBs. The test bearing consists of five pads with a diameter of 60 mm, and a resistance temperature detector (RTD) is installed in the pad for temperature monitoring. The test was performed by replacing the two loaded pads with the worn pad. The test result for the TPJB with wear depth of $30{\mu}m$ show that the temperatures of the loaded pads are $8^{\circ}C$ higher and that of the unloaded pad is $2.5^{\circ}C$ lower than that of the normal TPJB. In addition, the predicted pad temperature shows good agreement with the measured pad temperatures.


Supported by : 한국 연구 재단


  1. Ettles, C. M. McC, "The analysis and performance of pivoted pad journal bearings considering thermal and elastic effects", Journal of Lubrication Technology, Vol. 102, No. 2, pp. 182-191, 1980.
  2. Knight, J. D., Barrett, L. E., "Analysis of tilting pad journal bearings with heat transfer effects", Journal of Tribology, Vol. 110, No. 1, pp. 128-133, 1988.
  3. Brugier, D., Pascal, M. T., "Influence of elastic deformations of Turbo-Generator tilting pad bearings on the static behavior and on the dynamic coefficients in different designs", Journal of Tribology, Vol. 111, No. 2, pp. 364-371, 1989.
  4. Taniguchi, S., Makino, T., Takeshita, K., Ichimura, T., "A thermohydrbdynamic analysis of large tilting-pad journal bearing in laminar and turbulent flow regimes with mixing", Journal of Tribology, Vol. 112, No. 3, pp. 542-548, 1990.
  5. Suh, J., Palazzolo, A., "Three-dimensional dynamic model of TEHD Tilting-pad journal Bearing-Part I: Theoretical modeling", Journal of Tribology, Vol. 137, No. 4, pp. 014703, 2015.
  6. Su, J., Palazzolo, A., "Three-dimensional dynamic model of TEHD Tilting-Pad Journal Bearing-Part II: Parametric studies", Journal of Tribology, Vol. 137, No. 4, pp. 014704, 2015.
  7. Fillon, M., Bligoud, J., Frene, J., "Experimental study of Tilting-Pad Journal Bearings-Comparison with theoretical thermoelastohydrodynamic results", Journal of Tribology, Vol. 114, No. 3, pp. 579-587, 1992.
  8. Bang, K., Kim, J., Cho, Y., "Comparison of power loss and pad temperature for leading edge groove tilting pad journal bearings and conventional tilting pad journal bearings", Tribology International, Vol. 43, pp.1287-1293, 2010.
  9. Wygant, K. D., Flack, R. D., Barrett, L. E., "Measured performance of Tilting-Pad journal bearings over a range of Preloads-Part I: Static operating conditions", Tribology Transactions, Vol. 47, No. 4, pp. 576-584, 2004.
  10. Shu, J., Hwang, C., "Thermal deformation induced preload change in the tilting pad journal bearing," J. Korean Soc. Tribol. Lubr. Eng., Vol. 32, No. 1, pp. 1-8, 2016.
  11. Kim, T., Choi, T., Kim, C., "Rotordynamic performance predictions of tilting pad journal bearing with rocker-back pivots and comparison with published test results", J. Korean Soc. Tribol. Lubr. Eng., Vol. 31, No. 6, pp. 294-301, 2015.
  12. Lee, T., Kim, T., "Finite element analysis of pivot stiffness for tilting pad bearings and comparison to hertzian contact model calculations," J. Korean Soc. Tribol. Lubr. Eng., Vol. 30, No. 4, pp. 205-211, 2014.
  13. Whalen, J. K., Allen, J., Hess, T., Craighton, J., "Babbitted Bearing Health Assessment", Proceedings of the Forty First Turbomachinery Symposium, 2012.
  14. Dufrane, K. F., Kannel, J. W., McCloskey, T. H., "Wear of steam turbine journal bearings at low operating speeds", Journal of Lubrication Technology, Vol. 105, No. 2, pp. 182-191, 1983.
  15. Kumar, A., Mishra, S. S., "Steady state analysis of noncircular worn journal bearings in nonlaminar lubrication regimes", Tribology International, Vol. 29, No. 6, pp. 493-498, 1996.
  16. Scharrer, J. K., Hecht, R. F., Hibbs, R. I., "The Effects of wear on the rotordynamic coefficients of a hydrostatic journal bearing", Journal of Tribology, Vol. 113, No. 1, pp. 210-213, 1991.
  17. Fillon, M., Bouyer, J., "Thermohydrodynamic analysis of a worn plain journal bearing", Tribology International, Vol. 37, No. 4, pp. 129-136, 2004.
  18. Lee, D., Sun, K., "Thermohydrodynamic analysis and pad temperature measurement of a tilting pad journal bearing for a turbine simulator", J. Korean Soc. Tribol. Lubr. Eng., Vol. 33, No. 3, pp. 112-118, 2017.