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Boundary Lubrication in Transient Elliptical Contact: Part 1—Theoretical Formulation and Results

  • Di-Chu Xu
  • Qi Zhang
  • Jiu-Gen WangEmail author
Regular Paper
  • 34 Downloads

Abstract

The transient elliptical contacts in boundary lubrication widely exist in modern mechanical systems with high durability. However, little attention has been paid to the squeeze effect of fluid film in this condition. A deterministic model which combines the contact mechanics with the pure squeeze lubrication model has been developed with the aim of understanding the squeeze effect of fluid film under the transient boundary lubrication. The leakage coefficient was introduced to capture the fluid leakage of rough surfaces. The squeeze effect of trapped fluid film was confirmed through comparing the fluid film stiffness in boundary lubrication with that of the elastohydrodynamic lubrication. Additionally, the effects of fluid film entrapment/leakage on the boundary lubrication performance were numerically analyzed during transients. The load capacity of the squeeze films is built up due to the trapped fluid film in the micro-valleys, which can be significantly affected by the interfacial shear coefficient of the boundary films. The simulation results show a good agreement with the experiments and justify the present numerical model is feasible in the boundary lubrication regime.

Keywords

Boundary lubrication Squeeze film effect Junction growth Leakage 

Notes

Acknowledgements

Funding was provided by National Natural Science Foundation of China (Grant No. 51375436), National Hi-tech Research and Development Program of China (Grant No. 2015AA043002), and Key Project of Science and Technology of Zhejiang Province (Grant No. 2017C01047).

References

  1. 1.
    Greenwood, J. A., & Williamson, J. B. P. (1966). Contact of nominally flat surfaces. Proceedings of the Royal Society of London, 295(1442), 300–319.Google Scholar
  2. 2.
    Zhao, Y., Maietta, D. M., & Chang, L. (2000). An asperity microcontact model incorporating the transition from elastic deformation to fully plastic flow. Journal of Tribology, 122(1), 86–93.Google Scholar
  3. 3.
    Majumdar, A., & Bhushan, B. (1991). Fractal model of elastic–plastic contact between rough surfaces. ASME Journal of Tribology, 113(1), 1–11.Google Scholar
  4. 4.
    Jackson, R. L., & Green, I. (2011). On the modeling of elastic contact between rough surfaces. Tribology Transactions, 54(2), 300–314.Google Scholar
  5. 5.
    Bosman, R., Hol, J., & Schipper, D. J. (2011). Running-in of metallic surfaces in the boundary lubrication regime. Wear, 271(7), 1134–1146.Google Scholar
  6. 6.
    Müller, M., Jäschke, H., Bubser, F., & Ostermeyer, G. P. (2014). Simulative studies of tribological interfaces with partially filled gaps. Tribology International, 78(4), 195–209.Google Scholar
  7. 7.
    Dowson, D., & Jones, D. A. (1967). Lubricant entrapment between approaching elastic solids. Nature, 214(5091), 947–948.Google Scholar
  8. 8.
    Yang, P., & Wen, S. (1991). Pure squeeze action in an isothermal elastohydrodynamically lubricated spherical conjunction part 1. Theory and dynamic load results. Wear, 142(1), 1–16.Google Scholar
  9. 9.
    Yang, P., & Wen, S. (1991). Pure squeeze action in an isothermal elastohydrodynamically lubricated spherical conjunction part 2. Constant speed and constant load results. Wear, 142(1), 17–30.Google Scholar
  10. 10.
    Christensen, H. (1962). The oil film in a closing gap. Proceedings of the Royal Society A, 266, 312–328.Google Scholar
  11. 11.
    Dowson, D., & Wang, D. (1994). An analysis of the normal bouncing of a solid elastic ball on an oily plate. Wear, 179(1), 29–37.Google Scholar
  12. 12.
    Larsson, R., & Höglund, E. (1995). Numerical simulation of a ball impacting and rebounding a lubricated surface. Journal of Tribology, 117(1), 94–102.Google Scholar
  13. 13.
    Li, X. M., Guo, F., & Wong, P. L. (2011). Movement of entrapped oil under pure rolling conditions. Tribology Letters, 43(2), 129–137.Google Scholar
  14. 14.
    Wedeven, L. D., Evans, D., & Cameron, A. (1971). Optical analysis of ball bearing starvation. Journal of Tribology, 93(3), 349.Google Scholar
  15. 15.
    Liu, S., Wang, Q., & Liu, G. (2000). A versatile method of discrete convolution and FFT (DC–FFT) for contact analyses. Wear, 243(1), 101–111.Google Scholar
  16. 16.
    Wang, W. Z., Wang, H., Liu, Y. C., Hu, Y. Z., & Zhu, D. (2003). A comparative study of the methods for calculation of surface elastic deformation. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 217(2), 145–154.Google Scholar
  17. 17.
    Polonsky, I. A., & Keer, L. M. (1999). A numerical method for solving rough contact problems based on the multi-level multi-summation and conjugate gradient techniques. Wear, 231(2), 206–219.Google Scholar
  18. 18.
    Sahlin, F., Larsson, R., Almqvist, A., Lugt, P. M., & Marklund, P. (2010). A mixed lubrication model incorporating measured surface topography. Part 1: Theory of flow factors. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 224(4), 335–351.Google Scholar
  19. 19.
    Xu, D., & Wang, J. (2016). On deterministic elastoplastic contact for rough surfaces. Tribology, 3, 015.Google Scholar
  20. 20.
    Dowson, D., & Higginson, G. R. (1996). Elastohydrodynamic lubrication: The fundamentals of roller and gear lubrication. Oxford: Pergamon Press. ISBN: 978-0080114729.Google Scholar
  21. 21.
    Roelands, C. J. A., Vlugter, J. C., & Waterman, H. I. (1963). The viscosity–temperature–pressure relationship of lubricating oils and its correlation with chemical constitution. Journal of Fluids Engineering, 85(4), 601–607.Google Scholar
  22. 22.
    Masjedi, M., & Khonsari, M. M. (2015). On the effect of surface roughness in point-contact EHL: Formulas for film thickness and asperity load. Tribology International, 82, 228–244.Google Scholar
  23. 23.
    He, T., Zhu, D., Wang, J., & Wang, Q. J. (2017). Experimental and numerical investigations of the stribeck curves for lubricated counterformal contacts. Journal of Tribology, 139(2), 021505.Google Scholar

Copyright information

© Korean Society for Precision Engineering 2019

Authors and Affiliations

  1. 1.School of Mechanical EngineeringZhejiang UniversityHangzhouChina
  2. 2.Shuanghuan Driveline Co., LtdHangzhouChina

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