Effect of Inlet Shear Heating Due to Sliding on Elastohydrodynamic Film Thickness

Elastohydrodynamic film thickness was measured for a 20-mm ball bearing using the capacitance technique. The bearing was thrust loaded to 90, 448, and 778 N (20, 100, and 175 lb). The corresponding maximum stresses on the inner race were 1.28, 2.09, and 2.45 GPa (185,000, 303,000, and 356,000 psi). Test speeds ranged from 400 to 14,000 rpm. Film thickness measurements were taken with four different lubricants: (a) synthetic paraffinic, (b) synthetic paraffinic with additives, (c) neopentylpolyol (tetra) ester meeting MIL-L-23699A specifications, and (d) synthetic cycloaliphatic hydrocarbon traction fluid. The test bearing was mist lubricated. Test temperatures were 300, 338, and 393 K. The measured results were compared to theoretical predictions using the formulae of Grubin, Archard and Cowking, Dowson and Higginson, and Hamrock and Dowson. There was good agreement with theory at low dimensionless speed, but the film was much smaller than theory predicts at higher speeds. This was due to kinematic starvation and inlet shear heating effects. Comparisons with Chiu’s theory on starvation and Cheng’s theory on inlet shear heating were made.

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Anharmonic variations in elastohydrodynamic film thickness resulting from harmonically varying entrainment velocity

Proceedings of the Institution of Mechanical Engineers Part J Journal of Engineering Tribology ◽

10.1243/13506501jet669 ◽

2009 ◽

Vol 224 (3) ◽

pp. 239-247 ◽

Cited By ~ 5

Author(s):

P Kumar ◽

M M Khonsari ◽

S Bair

Keyword(s):

Film Thickness ◽

Entrainment Velocity ◽

Elastohydrodynamic Film Thickness

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Elastohydrodynamic Film Thickness Mapping by Computer Differential Colorimetry

Tribology Transactions ◽

10.1080/10402009908982229 ◽

1999 ◽

Vol 42 (2) ◽

pp. 361-368 ◽

Cited By ~ 16

Author(s):

M. Hartl ◽

I. Křupka ◽

M. Liška

Keyword(s):

Film Thickness ◽

Elastohydrodynamic Film Thickness

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An Analysis of Elastohydrodynamic Film Thickness in Tapered Roller Bearings

Elastohydrodynamics - '96 Fundamentals and Applications in Lubrication and Traction, Proceedings of the 23rd Leeds-Lyon Symposium on Tribology held in the Institute of Tribology, Department of Mechanical Engineering - Tribology Series ◽

10.1016/s0167-8922(08)70488-7 ◽

1997 ◽

pp. 617-637 ◽

Cited By ~ 4

Author(s):

R Yamashita ◽

D Dowson ◽

C M Taylor

Keyword(s):

Film Thickness ◽

Roller Bearings ◽

Tapered Roller ◽

Elastohydrodynamic Film Thickness ◽

Tapered Roller Bearings

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Paper 14: Measurement of Film Thickness in a Taper Roller Bearing

Proceedings of the Institution of Mechanical Engineers Conference Proceedings ◽

10.1243/pime_conf_1969_184_376_02 ◽

1969 ◽

Vol 184 (12) ◽

pp. 103-110

Author(s):

D. A. Jones ◽

A. B. Crease

Keyword(s):

Film Thickness ◽

Surface Finish ◽

Thrust Bearing ◽

Roller Bearing ◽

Rolling Contacts ◽

Rolling Elements ◽

Elastohydrodynamic Film Thickness ◽

Taper Roller Bearing

This paper describes an attempt to measure the elastohydrodynamic film thickness generated within the rolling contacts of a conventional taper roller thrust bearing. The technique used is simple and unambiguous and should be capable of application irrespective of the surface finish or geometry of the rolling elements.

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A Numerical Study of Friction in Isothermal EHD Rolling-Sliding Sphere-Plane Contacts With Spinning

Journal of Tribology ◽

10.1115/1.4001104 ◽

2010 ◽

Vol 132 (2) ◽

Cited By ~ 13

Author(s):

H. Dormois ◽

N. Fillot ◽

W. Habchi ◽

G. Dalmaz ◽

P. Vergne ◽

...

Keyword(s):

Film Thickness ◽

Numerical Study ◽

Friction Reduction ◽

Shear Stresses ◽

Fluid Viscosity ◽

Stress Distributions ◽

Eyring Model ◽

Element Approach ◽

Transverse Shear Stresses ◽

Shear Heating

This paper presents a study of the spinning influence on film thickness and friction in EHL circular contacts under isothermal and fully flooded conditions. Pressure and film thickness profiles are computed with an original full-system finite element approach. Friction was thereafter investigated with the help of a classical Ree–Eyring model to calculate the longitudinal and transverse shear stresses. An analysis of both the velocity and shear stress distributions at every point of the contact surfaces has allowed explaining the fall of the longitudinal friction coefficient due to the occurrence of opposite shear stresses over the contact area. Moreover in the transverse direction spinning favors large shear stresses of opposite signs, decreasing the fluid viscosity by non-Newtonian effects. These effects have direct and coupled consequences on the friction reduction that is observed in the presence of spinning. They are expected to further decrease friction in real situations due to shear heating.

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