0
Research Papers: Elastohydrodynamic Lubrication

Film Thickness and Rolling Resistance in Starved Elastohydrodynamic Lubrication of Point Contacts With Reflow

[+] Author and Article Information
Takashi Nogi

Japan Aerospace Exploration Agency,
7-44-1 Jindaiji-higashimachi,
Chofu, Tokyo 182-8522, Japan
e-mail: nogi.takashi@jaxa.jp

Contributed by the Tribology Division of ASME for publication in the JOURNAL OF TRIBOLOGY. Manuscript received December 29, 2014; final manuscript received March 12, 2015; published online April 29, 2015. Assoc. Editor: Xiaolan Ai.

J. Tribol 137(4), 041502 (Oct 01, 2015) (8 pages) Paper No: TRIB-14-1317; doi: 10.1115/1.4030203 History: Received December 29, 2014; Revised March 12, 2015; Online April 29, 2015

Elastohydrodynamic lubrication (EHL) film thickness and rolling resistance play a critical role in determining friction, wear, life, and other tribological characteristics of rolling bearings. Although film thickness formulas are widely used and experimentally verified, accurate prediction of the film thickness is still difficult under starved conditions. This paper presents a numerical study of starved EHL point contacts using a nonuniform inlet film thickness obtained from a modified Coyne–Elrod boundary condition. An experimental verification of the numerical results is also presented. Based on the results of a parametric study, inlet distance formulas are obtained as a function of the initial film thickness, the fully flooded central film thickness, and the capillary number. By using the inlet distance formulas and the Hamrock–Dowson formulas, the central film thickness, the minimum film thickness, and the viscous rolling resistance can be calculated.

Copyright © 2015 by ASME
Your Session has timed out. Please sign back in to continue.

References

Dowson, D., and Higginson, G. R., 1959, “A Numerical Solution to the Elastohydrodynamic Problem,” J. Mech. Eng. Sci., 1(1), pp. 6–15. [CrossRef]
Dowson, D., and Higginson, G. R., 1966, Elastohydrodynamic Lubrication, the Fundamentals of Roller and Gear Lubrication, Pergamon Press, Oxford, UK.
Hamrock, B. J., and Dowson, D., 1976, “Isothermal Elastohydrodynamic Lubrication of Point Contacts, Part I—Theoretical Formulation,” ASME J. Lubr. Technol., 98(2), pp. 223–229. [CrossRef]
Hamrock, B. J., and Dowson, D., 1976, “Isothermal Elastohydrodynamic Lubrication of Point Contacts, Part II—Ellipticity Parameter Results,” ASME J. Lubr. Technol., 98(3), pp. 375–381. [CrossRef]
Hamrock, B. J., and Dowson, D., 1977, “Isothermal Elastohydrodynamic Lubrication of Point Contacts, Part III—Fully Flooded Results,” ASME J. Lubr. Technol., 99(2), pp. 264–275. [CrossRef]
Wolveridge, P. E., Baglin, K. P., and Archard, J. F., 1970, “The Starved Lubrication of Cylinders in Line Contact,” Proc. Inst. Mech. Eng., 185(1), pp. 1159–1169. [CrossRef]
Wedeven, L. D., Evans, D., and Cameron, A., 1971, “Optical Analysis of Ball Bearing Starvation,” ASME J. Lubr. Technol., 93(3), pp. 349–363. [CrossRef]
Hamrock, B. J., and Dowson, D., 1977, “Isothermal Elastohydrodynamic Lubrication of Point Contacts, Part IV—Starvation Results,” ASME J. Lubr. Technol., 99(1), pp. 15–23. [CrossRef]
Chevalier, F., Lubrecht, A. A., Cann, P. M. E., Collin, F., and Dalmaz, G., 1998, “Film Thickness in Starved EHL Point Contacts,” ASME J. Tribol., 120(1), pp. 126–133. [CrossRef]
Elrod, H. G., Jr., 1981, “A Cavitation Algorithm,” ASME J. Lubr. Technol., 103(3), pp. 350–354. [CrossRef]
Cann, P. M. E., Damiens, B., and Lubrecht, A. A., 2004, “The Transition Between Fully Flooded and Starved Regions in EHL,” Tribol. Int., 37(10), pp. 859–864. [CrossRef]
Pemberton, J., and Cameron, A., 1976, “A Mechanism of Fluid Replenishment in Elastohydrodynamic Contacts,” Wear, 37(1), pp. 185–190. [CrossRef]
Coyne, J. C., and Elrod, H. G., Jr., 1970, “Conditions for the Rupture of a Lubricating Film, Part I: Theoretical Model,” ASME J. Lubr. Technol., 92(3), pp. 451–456. [CrossRef]
Coyne, J. C., and Elrod, H. G., Jr., 1971, “Conditions for the Rupture of a Lubricating Film, Part II: New Boundary Conditions for Reynolds Equation,” ASME J. Lubr. Technol., 93(1), pp. 156–167. [CrossRef]
Nogi, T., 2015, “An Analysis of Starved EHL Point Contacts With Reflow,” Tribol. Online, 10(1), pp. 64–75. [CrossRef]
Goksem, P. G., and Hargreaves, R. A., 1978, “The Effect of Viscous Shear Heating on Both Film Thickness and Rolling Traction in an EHL Line Contact—Part I: Fully Flooded Conditions,” ASME J. Lubr. Technol., 100(3), pp. 346–352. [CrossRef]
Aihara, S., 1987, “A New Running Torque Formula for Tapered Roller Bearings Under Axial Load,” ASME J. Tribol., 109(3), pp. 471–477. [CrossRef]
Zhou, R. S., and Hoeprich, M. R., 1991, “Torque of Tapered Roller Bearings,” ASME J. Tribol., 113(3), pp. 590–597. [CrossRef]
Goksem, P. G., and Hargreaves, R. A., 1978, “The Effect of Viscous Shear Heating on Both Film Thickness and Rolling Traction in an EHL Line Contact—Part II: Starved Conditions,” ASME J. Lubr. Technol., 100(3), pp. 353–358. [CrossRef]
Biboulet, N., and Houpert, L., 2010, “Hydrodynamic Force and Moment in Pure Rolling Lubricated Contacts. Part 1: Line Contacts,” Proc. Inst. Mech. Eng., Part J, 224(8), pp. 765–775. [CrossRef]
Biboulet, N., and Houpert, L., 2010, “Hydrodynamic Force and Moment in Pure Rolling Lubricated Contacts. Part 2: Point Contacts,” Proc. Inst. Mech. Eng., Part J, 224(8), pp. 777–787. [CrossRef]
Ankouni, M., Biboulet, N., and Lubrecht, A. A., 2013, “Load Carrying Capacity and Friction in Starved Hydrodynamically Lubricated Circular Contacts,” Proc. Inst. Mech. Eng., Part J, 227(12), pp. 1438–1444. [CrossRef]
Nogi, T., and Kato, T., 1997, “Influence of a Hard Surface Layer on the Limit of Elastic Contact—Part I: Analysis Using a Real Surface Model,” ASME J. Tribol., 119(3), pp. 493–500. [CrossRef]
Liu, S., Wang, Q., and Liu, G., 2000, “A Versatile Method of Discrete Convolution and FFT (DC-FFT) for Contact Analyses,” Wear, 243(1–2), pp. 101–111. [CrossRef]
Wang, W. Z., Wang, H., Liu, Y. C., Hu, Y. Z., and Zhu, D., 2003, “A Comparative Study of the Methods for Calculation of Surface Elastic Deformation,” Proc. Inst. Mech. Eng., Part J, 217(2), pp. 145–154. [CrossRef]
de Vicente, J., Stokes, J. R., and Spikes, H. A., 2006, “Rolling and Sliding Friction in Compliant, Lubricated Contact,” Proc. Inst. Mech. Eng., Part J, 220(2), pp. 55–63. [CrossRef]
Guangteng, G., Cann, P. M. E., and Spikes, H. A., 1992, “A Study of Parched Lubrication,” Wear, 153(1), pp. 91–105. [CrossRef]
Guangteng, G., and Spikes, H. A., 1996, “The Role of Surface Tension and Disjoining Pressure in Starved and Parched Lubrication,” Proc. Inst. Mech. Eng., Part J, 210(2), pp. 113–124. [CrossRef]

Figures

Grahic Jump Location
Fig. 1

Example of the boundaries and a micrograph around the contact

Grahic Jump Location
Fig. 2

Example of the film thicknesses outside the boundaries

Grahic Jump Location
Fig. 3

Schematic diagram of the EHL traction apparatus

Grahic Jump Location
Fig. 4

Schematic diagram of the principle of the rolling resistance measurement

Grahic Jump Location
Fig. 5

A set of the traction curves in the CW and CCW directions

Grahic Jump Location
Fig. 6

The dimensionless pressure (top) and the dimensionless film thickness (bottom)

Grahic Jump Location
Fig. 7

The ratio of the film thickness to the gap height (top) and the dimensionless shear stress (bottom)

Grahic Jump Location
Fig. 8

Comparison between the numerical and experimental results for the dimensionless central film thickness

Grahic Jump Location
Fig. 9

Comparison between the numerical and experimental results for the dimensionless minimum film thickness

Grahic Jump Location
Fig. 10

Comparison between the numerical and experimental results for the dimensionless viscous rolling resistance

Grahic Jump Location
Fig. 11

Effect of the capillary number and the dimensionless initial film thickness on the dimensionless inlet distance

Grahic Jump Location
Fig. 12

Effect of the dimensionless fully flooded central film thickness on the dimensionless inlet distance

Grahic Jump Location
Fig. 13

Relation between the reduction factor of the central film thickness and the inlet boundary parameter

Grahic Jump Location
Fig. 14

Relation between the reduction factor of the minimum film thickness and the inlet boundary parameter

Grahic Jump Location
Fig. 15

Relation between the reduction factor of the viscous rolling resistance and the inlet boundary parameter

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In