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http://dx.doi.org/10.9725/kstle.2015.31.3.109

Study on Wear of Journal Bearings during Start-up and Coast-down Cycles of a Motoring Engine - I. Theory and Analysis Procedure  

Chun, Sang Myung (Dept. of Automotive Engineering, Hoseo University)
Publication Information
Tribology and Lubricants / v.31, no.3, 2015 , pp. 109-124 More about this Journal
Abstract
This paper presents a wear analysis procedure for the journal bearings on a stripped-down single-cylinder engine during start-up and coast-down by motoring. A journal bearing is in the mixed elastohydrodynamic (EHL) lubrication region when the shaft speed is less than the corresponding lift-off speed. Below the lift-off speed, a wear scar can form on bearing surfaces. In part 1 of this paper, we develop the appropriate formulations and the calculation procedure for the analysis. Specifically, we formulate an equation for modified film thickness in a journal bearing considering the additional wear volume. In order to obtain the modified specific wear rate induced by the modified Archard’s wear coefficient, we utilized the extended non-dimensional diagram for the specific wear rate, k, the fractional film defect coefficient, Ψ and the asperity load sharing factor, γ2. This asperity load sharing factor is newly calculated by setting the Zhao-Maietta-Chang (ZMC) asperity contact pressure equation coupled with the central film thickness equation derived by using the ZMC asperity contact model equal to the modified central contact pressure derived by using the central (or maximum) contact pressure at the dry rough line-contact configuration. We can use the procedure introduced in this paper to determine the lifetime (or longterm) linear wear in radial journal bearings that is a result of repeated stop-start cycles.
Keywords
asperity contact; lift-off speed; mixed elastohydrodynamic lubrication; start-up and coast-down cycle; wear volume;
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1 Beheshti, A., Khonsari, M. M., “An Engineering Approach for the Prediction of Wear in Mixed Lubricated Contacts”, Wear, Vol. 308, pp. 121-131. http://dx.doi.org/10.1016/j.wear.2013.10.004, 2013.   DOI
2 Beheshti, A., Khonsari, M. M., ”Asperity Microcontact Models as Applied to the Deformation of Rough Line Contact”, Tribol. Int., Vol. 52, pp. 61-74. http://dx.doi.org/10.1016/j.triboint.2012.02.026, 2012.   DOI
3 Hamrock, B. J., Fundamentals of Fluid Film Lubrication, McGraw Hill, New York; London, 1994.
4 Holm, R., Electrical contacts, Almqvist & Wiksell, Stockholm, 1946.
5 Chun, S. M., “Simulation of Engine Life Time Related with Abnormal Oil Consumption”, Tribol. Int., Vol. 44, pp. 426-436. DOI:10.1016/j.triboint.2010.11.020, 2011.   DOI
6 Archard, J. F., “Contact and rubbing of flat surfaces”, J. Appl. Phys., Vol. 24, pp. 981-988, 1953.   DOI
7 Ligterink, D. J., de Gee, A. W. J., “Measurements of Wear in Radial Journal Bearings”, Tribotest Journal, Vol. 3, No.1, pp.45-54. 1354-4063, 1996.   DOI
8 Kingsbury, E. P., “Some Aspect of the thermal desorption of a boundary lubricant”, J. Appl. Phys, Vol. 29, pp. 888-891, 1958.   DOI
9 Rowe, C. N., “Some aspects of heat of adsorption in function of a boundary lubricant”, ASLE Trans., Vol. 9, pp. 101-111, 1966.   DOI
10 Shi, F., Wang, Q. J., “A Mixed-TEHD Model for Journal-Bearing Conformal Contacts – Part I: Model Formulation and Approximation of Heat Transfer Considering Asperity Contact”, Trans. ASME, J. Tribol., Vol. 120, pp. 198-205, 1998.   DOI
11 Majumdar, B. C., Hamrock, B. J., “Effect of Surface Roughness on Elaostohydrodynamic Line Contact”, ASME J. Lubr. Technol., No. 104, pp. 401-409, 1982.
12 Khonsari, M. M., Booser, E. R., Applied Tribology: Bearing Design and Lubrication, Wiley, New York, 2008.
13 Masjedi, M., Khonsari, M. M., “Film Thickness and Asperity Load Formulas for Line-Contact Elastohydro-dynamic Lubrication with Provision for Surface Roughness”, Trans. ASME, J. Tribol., Vol. 134, No. 1, 011503. DOI: 10.1115/ 1.40005514, 2012.
14 Chang, W. R., Etsion, I., Bogy, D. B., “An Elastic-Plastic Model for the Contact of Rough Surfaces”, Trans. ASME, J. Tribol., Vol. 109, pp. 257-263, 1987.   DOI
15 Zhao, Y., Maietta, D. M., Chang, L., “An Asperity Microcontact Model Incoporating the Transition from Elastic Deformation to Fully Plastic Flow”, Trans. ASME, J. Tribol., Vol. 122, pp. 86-93, 2000.   DOI
16 Kogut, L., Etsion, I., “A Finite Element based Elastic-Plastic Model for the Contact of Rough Surfaces”, Tribol. Trans., Vol. 46, pp. 383-390, 2003.   DOI
17 Masjedi, M., Khonsari, M. M., “Theoretical and Experimental Investigation of Traction Coefficient in Line-contact EHL of Rough surfaces,” Tribol. Int., Vol. 70, pp. 179-189, http://dx.doi.org/10.1016/j.triboint. 2013.10.004, 2014   DOI
18 Vogelpohl, G. “Thermal Effects and Elasto-Kinetics in Self-acting Bearing Lubricationx”, Proceedings of International Symposium on Lubrication and Wear, Huston, pp. 766-815, 1965.
19 McCool, J. I., “Relating Profile Instrument Measurements to the Functional Performance of Rough Surfaces”, Trans. ASME, J. Tribol., Vol. 109. No. 2, pp. 264-270, 1987.
20 Vogelpohl, G., “Geringste zulässige Schmierschichtdicke und Übergangsdrehzahl”, Konstruktion, Vol. 14, No. 12, pp. 461-468, 1962.
21 Lu, X., Khonsari, M. M., “On the Lift-Off Speed in Journal Bearings”, Tribol. Lett., Vol. 20, No. 3-4, pp. 299-305. DOI: 10.1007/s11249-005-9124-y, 2005.   DOI
22 Chun, S. M., “Aeration Effects on the Performance of a Turbocharger Journal Bearing”, Tribol. Int., Vol. 41, pp. 296-306, DOI:10.1016/j.triboint.2007.08.006, 2008.   DOI
23 Landheer, D., Faessen, J. F. M., de Gee, A. W. J., “A transition diagram for plain journal bearings”, Tribol. Trans., Vol. 33, pp. 418-424, 1990.   DOI
24 Illner, T., Bartel, D., Deters, L., “Determination of the Transition Speed in Journal Bearings under Consideration of Bearing Deformation”, Tribol. Int., Vol. 82, pp. 58-67, 2015.   DOI
25 Chun, S. M., Lalas, D. P., “Parametric Study of Inlet Oil Temperature and Pressure for a Half-Circum- ferential Grooved Journal Bearing”, Tribol. Trans., Vol. 35, No. 2, pp. 213-224, 1992.   DOI
26 Patir, N., Cheng, H. S., “An average Flow Model for Determining Effects of Three-Dimensional Roughness on Partial Hydrodynamic Lubrication”, ASME J. Lubr. Technol., Vol. 100, pp. 12-17, 1978.   DOI
27 Booker, J. F., “Dynamically Loaded Journal Bearings: Mobility Method of Solution”, ASME J. Basic Engineering, Vol. 87, pp. 537-546, 1965.   DOI
28 Patir, N., Cheng, H. S., “Application of Average Flow Model to Lubrication between Roughness Sliding Surfaces”, ASME J. Lubr. Technol., Vol. 101, pp. 220-230, 1979.   DOI
29 Chun, S. M., Parametric Study of Thermal and Unsteady Effects in Hydrodynamic Lubrication of Journal Bearings, Ph.D. thesis, Wayne State University, Detroit, Michigan, 1989.
30 Fragoulis, A. H., Instantaneous Frictional Torque of Reciprocating Combustion Engines, Ph.D. thesis, Wayne State University, Detroit, Michigan, 1988.