Hydrodynamic performance of gas microbearings, fabricated with deep X-ray lithography and electroplating, will be presented in this article. Static performance in terms of load parameters and attitude angles was calculated using Molecular Gas Lubrication (MGL) theory. Threshold speed and allowable rotor mass were calculated to investigate safe operating conditions of the fabricated gas microbearings using orbit simulation. Finally, improved bearing designs were proposed to increase stability.

Issue Section:
Research Papers
Keywords:
hydrodynamics, X-ray lithography, electroplating, machine bearings, numerical analysis, lubrication
Topics:
Bearings, Journal bearings, Stress, Thrust bearings, Stability, Numerical analysis, Rotors, X-ray lithography, Lubrication
1.
Frechette, L. G., Jacobson, S. A., Enrich, F. F., Ghodssi, R., Khanna, R., Wong, C. W., Zhang, X., Breuer, K. S., Schmidt, M. A., and Epstein, A. H., 2001, “Demonstration of a Microfabricated High-Speed Turbine Supported on Gas Bearings,” Proc. Solid-State Sensor and Actuator Workshop, Hilton Head, NC.
2.
Orr, D. J., 1999, Macro-Scale Investigation of High Speed Gas Bearings for MEMS Devices, PhD. Thesis, MIT, Cambridge.
3.
Gad-el-Hak, M. 2001, The MEMS Handbook, CRC Press Boca Raton, FL, pp. 9–24.
4.
Feiertag
,
G.
,
Ehrfeld
,
W.
,
Lehr
,
H.
,
Schmidt
,
A.
, and
Schmidt
,
M.
,
1997
, “
Accuracy of Structure Transfer in Deep X-ray Lithography
,”
Microelectron. Eng.
,
35
, pp.
557
–
560
.
5.
Guckel
,
H.
,
1998
, “
High-Aspect-Ratio Micromachining Via Deep X-ray Lithography
,”
Proc. IEEE
,
86
(
8
), pp.
1586
–
1593
.
6.
Malek
,
C. K.
,
Jacson
,
K. H.
,
Bonivert
,
W. D.
, and
Hruby
,
J.
,
1996
, “
Masks for High Aspect Ratio X-ray Lithography
,”
J. Micromech. Microeng.
,
6
, pp.
228
–
235
.
7.
Kim
,
D.
,
Lee
,
S.
,
Jin
,
Y.
,
Desta
,
Y.
,
Bryant
,
M. D.
, and
Goettert
,
J.
,
2003
, “
Micro Gas Bearing Fabricated by Deep X-ray Lithography
,” Microsys. Technol., in press.
8.
Cameron, A., 1966, The Principles of Lubrication, Wiley, New York.
9.
Fukui
,
S.
, and
Kaneko
,
R.
,
1988
, “
Analysis of Ultra-Thin Gas Film Lubrication Based on Linearized Boltzman Equation: First Report-Derivation of Generalized Lubrication Equation Including Thermal Creep Flow
,”
ASME J. Tribol.
,
110
, p.
253
–
262
.
10.
Kang, S. C., 1997, A Kinetic Theory Description for Molecular Lubrication, Ph.D. thesis, Carnegie Mellon University.
11.
Burgdorfer
,
A.
,
1959
, “
The Influence of the Molecular Mean Free Path on the Performance of Hydrodynamic Gas Lubricated Bearings
,”
ASME J. Basic Eng.
,
81
, p.
94
–
100
.
12.
Patankar, S. V., 1980, Numerical Heat Transfer and Fluid Flow, McGraw-Hill, New York.
13.
Yum, K., 2002, Numerical Simulation of Micro Air-Lubricated Journal Bearings for 3-D Microactuators, MS thesis, Mech. Eng., UT-Austin.
14.
Pirro, D. M., and Wessol, A. A., Lubrication Fundamentals, 2nd edition, Exxon Mobil, 2001.
15.
Pan, C. H. T., Kim, D., and Bryant, M. D., 2003, “Dynamic Analysis of the Long Plain Journal Bearing in the Nanotechnology Environment,” 2nd Int. Symp. on Stability Control of Rotating Machinery (ISCORMA-2), Gdansk, Poland.
16.
Cheng
,
H. S.
, and
Pan
,
C. H. T.
,
1965
, “
Stability Analysis of Gas-Lubricated, Self-Acting, Plain, Cylindrical, Journal Bearings of Finite Length, Using Galerkin’s Method
,”
ASME J. Basic Eng.
,
87
(
1
), pp.
185
–
192
.
17.
Castelli
,
V.
, and
Elrod
,
H. G.
,
1965
, “
Solution of the Stability Problem for 360° Self-Acting, Gas-Lubricated Bearings
,”
ASME J. Basic Eng.
,
87
(
1
), pp.
199
–
210
.
18.
Fuller
,
D.
,
1969
, “
A Review of the State-of-the-Art for the Design of Self Acting Gas-Lubricated Bearings
,”
ASME J. Lubr. Technol.
,
91
(
1
), pp.
1
–
16
.
19.
Piekos
,
E. S.
, and
Breuer
,
K. S.
,
1999
, “
Peusospectral Orbit Simulation of Nonideal Gas-Lubricated Journal Beariongs for Microfabricated Turbomachines
,”
ASME J. Tribol.
,
121
, pp.
604
–
609
.
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 by ASME
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