Lubricant flow properties of polyalphaolefin (PAO) oil have been experimentally investigated based on a ball-on-disc configuration under micro oil supply condition. The oil pool shape and central film thickness in the contact region were obtained using fluorescence microscopy and optical interferometry, respectively. It has been found that the relative length between the inlet meniscus and Hertzian center point in the oil pool to Hertzian radius was much larger than 1 in a smaller lubricant supply of 20 μl, and the corresponding contact region initially entered the elastohydrodynamic lubrication (EHL) region and then became starved with the increasing speed. The variations of the relative film thickness as a function of starvation degree and the ratio of relative length to Hertzian radius were proposed to explain the obtained results. Besides, the fluorescence technique was used to directly observe the inlet meniscus position of the oil pool and helped to gain more understanding of the lubricant flow properties under micro oil supply condition.

References

1.
Chevalier
,
F.
,
Lubrecht
,
A. A.
,
Cann
,
P. M. E.
,
Colin
,
F.
, and
Dalmaz
,
G.
, 1995, “
Starved Film Thickness: A Qualitative Explanation
,”
Tribol. Ser.
,
33
, pp.
249
257
.
2.
Chevalier
,
F.
,
Lubrecht
,
A. A.
,
Cann
,
P. M. E.
,
Colin
,
E.
, and
Dalmaz
,
G.
, 1998, “
Film Thickness in Starved EHL Point Contacts
,”
ASME J. Tribol.
,
120
, pp.
126
133
.
3.
Guangteng
,
G.
, 1993, “
A Study of Squeeze and Starvation in Elastohydrodynamic Lubrication
,”
Ph.D. thesis
,
University of London
,
London, UK
.
4.
Wedeven
,
L. D.
,
Evans
,
D.
, and
Cameron
,
A.
, 1971, “
Optical Analysis of Ball Bearing Starvation
,”
ASME J. Lubr. Technol.
,
93
, pp.
349
363
.
5.
Chiu
,
Y. P.
, 1974, “
An Analysis and Prediction of Lubricant Starvation in Following Contact Systems
,”
ASLE Trans.
,
17
, pp.
22
35
.
6.
Pemberton
,
J.
,
Evans
,
D.
, and
Cameron
,
A.
, 1976, “
A Mechanism of Fluid Replenishment in Elastohydronamic Contacts
,”
Wear
,
37
, pp.
184
190
.
7.
Hamrock
,
B. J.
, and
Dowson
,
D.
, 1977, “
Isothermal Elastohydrodynamic Lubrication of Point Contacts, Part IV, Starvation Results
,”
ASME J. Lubr. Technol.
,
99
, pp.
15
23
.
8.
Damiens
,
B.
,
Venner
,
C. H.
,
Cann
,
P. M. E.
, and
Lubrecht
,
A. A.
, 2005, “
Starvation Lubrication of Elliptical EHD Contacts
,”
ASME J. Tribol.
,
126
, pp.
105
111
.
9.
Wen
,
S. Z.
, 1990,
Principles of Tribology
, 1st ed.,
Tsinghua University Press
,
Beijing
.
10.
Venner
,
C. H.
,
Popovici
,
G.
,
Lugt
,
P. M.
, and
Organisciak
,
M.
, 2008, “
Film Thickness Modulations in Starved Elastohydrodynamically Lubricated Contacts Induced by Time-Varying Lubricant Supply
,”
ASME J. Tribol.
,
130
, p.
041501
.
11.
Hiromu
,
H.
, and
Masayuki
,
O.
, 2010, “
Stabilization Method for Small-Bore Journal Bearings Utilizing Starved Lubrication
,”
ASME J. Tribol.
,
132
, p.
011703
.
12.
Damiens
,
B.
,
Lubrecht
,
A. A.
, and
Cann
,
P. M. E.
, 2001, “
Lubrication Regimes in Rolling Element Bearings
,”
Tribol. Ser.
,
39
, pp.
295
301
.
13.
Cann
,
P. M. E.
,
Damiens
,
B.
, and
Lubrecht
,
A. A.
, 2004, “
The Transition Between Fully Flooded and Starved Regimes in EHL
,”
Tribol. Int.
,
37
, pp.
859
864
.
14.
Faraon
,
I. C.
, and
Schipper
,
D. J.
, 2007, “
Stribeck Curve for Starved Line Contacts
,”
ASME J. Tribol.
,
129
, pp.
181
187
.
15.
Smart
,
A. E.
, and
Ford
,
R. A. J.
, 1974, “
Measurement of Thin Liquid Films by A Fluorescence Technique
,”
Wear
,
29
, pp.
41
47
.
16.
Ting
,
L. L.
, 1980, “
Development of a Laser Fluorescence Technique for Measuring Piston Ring Oil Film Thickness
,”
J. lubr. Tech.
,
102
, pp.
165
170
.
17.
Sugimuar
,
J.
,
Hashimoto
,
M.
, and
Yamamoto
,
Y.
, 2000, “
Study of Elastohydrodynamic Contacts With Fluorescence Microscope
,”
Tribol. Ser.
,
35
, pp.
609
617
.
18.
Sugimuar
,
J.
, and
Akiyama
,
M.
, 2001, “
Study of Non-Steady State Grease Lubrication With Fluorescent Microscope
,”
Tribol. Ser.
,
39
, pp.
285
294
.
19.
Myant
,
C.
,
Reddyhoff
,
T.
, and
Spikes
,
H. A.
, 2010, “
Laser-Induced Fluorescence for Film Thickness Mapping in Pure Sliding Lubricated, Compliant, Contacts
,”
Tribol. Int.
,
43
, pp.
1960
1969
.
20.
Azushima
,
A.
,
Yanagida
,
A.
, and
Tani
,
S.
, 2011, “
Permeation of Lubricant Trapped Within Pocket Into Real Contact Area on the End Surface of Cylinder
,”
ASME J. Tribol.
,
133
, p.
011501
.
21.
Pit
,
R.
,
Hervet
,
H.
, and
Leger
,
L.
, 1999, “
Friction and Slip of a Simple Liquid at a Solid Surface
,”
Tribol. Lett.
,
7
, pp.
147
152
.
22.
Reddyhoff
,
T.
,
Choo
,
J. H.
,
Spikes
,
H. A.
, and
Glovnea
,
R. P.
, 2010, “
Lubricant Flow in an Elastohydrodynamic Contact Using Fluorescence
,”
Tribol. Lett.
,
38
, pp.
207
215
.
23.
Qian
,
S. H.
,
Guo
,
D.
,
Liu
,
S. H.
, and
Lu
,
X. C.
, 2011, “
Experimental Investigation of the Lubrication Failure of Polyaolefin Oil Film at High Slide/Roll Ratios
,”
Tribol. Lett.
,
44
, pp.
107
115
.
24.
Xiao
,
H. P.
,
Guo
,
D.
,
Liu
,
S. H.
,
Xie
,
G. X.
,
Pan
,
G. S.
,
Lu
,
X. C.
, and
Luo
,
J. B.
, 2011, “
Direct Observation of Oil Displacement by Water Flowing Toward an Oil Nanogap
,”
J. Appl. Phys.
,
110
, p.
044906
.
25.
Ma
,
L. R.
, and
Zhang
,
C. H.
, 2009, “
Discussion on the Technique of Relative Optical Interference Intensity for the Measurement of Lubricant Film Thickness
,”
Tribol. Lett.
,
36
, pp.
239
245
.
26.
Luo
,
J. B.
,
Wen
,
S. Z.
, and
Huang
,
P.
, 1996, “
Thin Film Lubrication. Part I. Study on the Transition Between EHL and Thin Film Lubrication Using a Relative Optical Interference Intensity Technique
,”
Wear
,
194
, pp.
107
115
.
27.
Xie
,
G. X.
,
Luo
,
J. B.
,
Liu
,
S. H.
,
Guo
,
D.
, and
Zhang
,
C. H.
, 2011, “
Nanoconfined Liquid Aliphatic Compounds Under External Electric Fields: Roles of Headgroup and Alkyl Chain Length
,”
Soft Matter
,
7
, pp.
4453
4460
.
28.
Xie
,
G. X.
,
Luo
,
J. B.
,
Liu
,
S. H.
,
Guo
,
D.
, and
Zhang
,
C. H.
, 2010, “
Electric-Fields-Enhanced Destabilization of Oil-In-Water Emulsions Flowing Through a Confined Wedgelike Gap
,”
J. Appl. Phys.
,
108
, p.
064314
.
29.
Xiao
,
H. P.
,
Guo
,
D.
,
Liu
,
S. H.
,
Lu
,
X. C.
, and
Luo
,
J. B.
, 2010, “
Experimental Investigation of Lubrication Properties at High Contact Pressure
,”
Tribol. Lett.
,
40
, pp.
85
97
.
30.
Xie
,
G. X.
,
Luo
,
J. B.
,
Liu
,
S. H.
,
Guo
,
D.
, and
Zhang
,
C. H.
, 2011, “
Thin Liquid Film Lubrication Under External Electrical Fields: Roles of Liquid Intermolecular Interactions
,”
J. Appl. Phys.
,
109
, p.
114302
.
31.
Du
,
H. S.
, 1999, “
Study on Elastohydrodynamic Lubrication With Fluorescent Technique
,”
Ph.D. thesis
,
Tsinghua University
,
Beijing
.
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