We investigated the lubricating characteristics between a vane and piston lubricated with an oil-refrigerant mixture. Theoretical analyses were performed using mixed elastohydrodynamic lubrication analysis theory, taking metallic contacts into account. Lubricating conditions were evaluated by comparing the theoretical results of piston dynamics based on actual surface roughness distributions measured by SEM, with the experimental results measured under practical operation. We conclude that (1) lubricating conditions between the vane and piston can be assumed to be within the mixed lubricating zone, in which the coefficient of friction changes from 0.04 to 0.08, and the contact force is almost equally supported by oil film and metallic contact; (2) the coefficient of friction decreases as the contact force increases because the ratio of pressure rise of the oil film to the decrease in clearance is much greater than that for metallic contact pressure; and (3) in mixed EHL analysis, it is important not only to measure the actual surface roughness but also to select the appropriate contact model.

Issue Section:
Research Papers
Topics:
Clearances (Engineering), Compressors, Dynamics (Mechanics), Elastohydrodynamic lubrication, Friction, Pistons, Pressure, Refrigerants, Surface roughness, Theoretical analysis
1.
Greenwood, J. A., and Williamson, J. B. P., 1966, “Contact of Nominally Flat Surfaces,” Proceedings of the Royal Society (London), Series 295A, pp. 300–319.
2.
Greenwood
J. A.
, and
Tripp
J. H.
,
1970
, “
The Contact of Two Nominally Flat Rough Surfaces
,”
Proceedings of The Institution of Mechanical Engineering Part I
, Vol.
185
, No.
48
, pp.
625
–
633
.
3.
Kobayashi
H.
,
1993
, “
Tribology of Rotor and Blade in Rotary Compressor
,”
The Tribologist (in Japanese)
, Vol.
38
, No.
7
, pp.
599
–
604
.
4.
Padhy
S. K.
,
1993
, “
On the dynamics of a rotary compressor: part 1— Mathematical modeling
,”
Advances In Design Automation—Volume 1
, ASME, DE-Vol.
65–1
, pp.
207
–
217
.
5.
Padhy
S. K.
,
1993
, “
On the Dynamics of a Rotary Compressor: Part 2—Experimental Validation and Sensitivity
,”
Advances In Design Automation—Volume 1
, ASME, DE-Vol.
65–1
, pp.
219
–
227
.
6.
Patir
N.
, and
Cheng
H. S.
,
1970
, “
Effect of Surface Roughness Orientation on the Central Film Thickness in E. H. D. Contacts
,”
Proceedings of the Institute of Mechanical Engineering Part I
, Vol.
185
, No.
48
, pp.
15
–
21
.
7.
Patir
N.
, and
Cheng
H. S.
,
1978
, “
An Average Flow Model for Determining Effects of Three-Dimensional Roughness on Partial Hydrodynamic Lubrication
,”
ASME JOURNAL OF LUBRICATION TECHNOLOGY
, Vol.
100
, pp.
12
–
17
.
8.
Shimizu
T.
,
1976
, “
Frictional Loss on Rolling Piston of Air conditioning Rotary Compressor
,”
Refrigeration (in Japanese)
, Vol.
51
, No.
589
, pp.
959
–
965
.
9.
Tanaka
S.
,
1996
, “
Lubrication Characteristics of Refrigerator/Air Conditioning Rotary Compressor
,”
The Tribologist (in Japanese)
, Vol.
41
, No.
3
, pp.
247
–
254
.
10.
Yanagisawa
T.
,
1982
, “
Motion Analysis of Rolling Piston in Rotary Compressor
,”
Transactions of JSME, Series C (in Japanese)
, Vol.
48
, No.
429
, pp.
732
–
740
.
11.
Kreisle
L. F.
,
1956
, “
Very Short Journal-Bearing Hydrodynamic Performance Under Conditions Approaching Marginal Lubrication
,”
Trans. ASME
, Vol.
78
, p.
955
955
.
12.
Peeken
H.
,
1960
, “
Die Berechnung extrem kurzer Gleitlager
,”
Konstruktion
, Vol.
12
, No.
3
, pp.
104
–
110
.
13.
Leung
M.
,
Hiseh
C. K.
, and
Goswami
D. Y.
,
1997
, “
Application of Boltzman Statistical Mechanics in the Validation of the Gaussian Summit-Height Distribution In the Rough Surfaces
,”
ASME JOURNAL OF TRIBOLOGY
, Vol.
119
, pp.
846
–
850
.
This content is only available via PDF.
Copyright © 1999
 by Journal of Tribology
You do not currently have access to this content.