A numerical model has been developed to analyze both static and dynamic characteristics of a coupled porous journal and thrust bearing system that is used to support a rotating shaft in a magnetic hard disk drive. The analyzed system is composed of a porous sleeve, a herringbone-grooved solid thrust plate and a flanged shaft, where the bottom end is closed to form a cantilever spindle. The inner surface and the bottom face of the porous sleeve operate as a herringbone-grooved journal and thrust bearing, respectively. The model is based on the narrow groove theory for the bearing oil film, and Darcy’s law for the internal flow in the porous sleeve. The pressure distribution, static equilibrium position of the shaft and dynamic coefficients are obtained under a given external axial load. There exists a window of permeability of the porous sleeve that presents significant advantage to prevent the creation of a sub-ambient condition and to maintain a large thrust bearing film thickness at the expense of some loss of dynamic performance.

Issue Section:
Technical Papers
Keywords:
numerical analysis, machine bearings, disc drives, hard discs, porous materials, tribology, Fluid Film Bearing, Porous Bearing, Journal Bearing, Thrust Bearing, Hard Disk Drive
Topics:
Bearings, Equilibrium (Physics), Permeability, Pressure, Thrust bearings, Numerical analysis, Clearances (Engineering), Disks, Flow (Dynamics)
1.
Zirkelback
,
N.
, and
San Andres
,
L.
,
1998
, “
Finite Element Analysis of Herringbone Groove Journal Bearings: A Parametric Study
,”
ASME J. Tribol.
,
120
, pp.
234
–
240
.
2.
Zhu
,
J.
, and
Ono
,
K.
,
1999
, “
A Comparison Study on the Performance of Four Types of Oil Lubricated Hydrodynamic Thrust Bearings for Hard Disk Spindles
,”
ASME J. Tribol.
,
121
, pp.
114
–
120
.
3.
Jang
,
G. H.
, and
Kim
,
Y. J.
,
1999
, “
Calculation of Dynamic Coefficients in a Hydrodynamic Bearing Considering Five Degrees of Freedom for a General Rotor-Bearing System
,”
ASME J. Tribol.
,
121
, pp.
499
–
505
.
4.
Jang
,
G. H.
, and
Chang
,
D. I.
,
2000
, “
Analysis of a Hydrodynamic Herringbone Grooved Journal Bearing Considering Cavitation
,”
ASME J. Tribol.
,
122
, pp.
103
–
109
.
5.
Hirayama, T., and Yabe, H., 2001, “A Study on Operating Characteristics of Spiral Grooved Journal Bearings—An Investigation of the Boundary Contour of Gas–Liquid Interface,” Proc. International Tribology Conference Nagasaki, 2000, K. Ichimaru et al., eds., JST, Tokyo, III, pp. 1633–1638.
6.
Zhang, Q. D., Winoto, S. H., Chen, S. X., and Chong, H. C., 2001, “Design of Fluid Film Bearing for Spindle Motor in Hard Disk Drives,” Proc. International Tribology Conference Nagasaki, 2000, K. Ichimaru et al., eds., JST, Tokyo, III, pp. 1645–1650.
7.
Jang
,
G. H.
, and
Yoon
,
J. W.
,
2002
, “
Nonlinear Dynamic Analysis of a Hydrodynamic Journal Bearing Considering the Effect of a Rotating or Stationary Herringbone Groove
,”
ASME J. Tribol.
,
124
, pp.
297
–
304
.
8.
Jang
,
G. H.
, and
Yoon
,
J. W.
,
2003
, “
Stability Analysis of a Hydrodynamic Journal Bearing With Rotating Herringbone Grooves
,”
ASME J. Tribol.
,
125
, pp.
291
–
300
.
9.
Zang, Y., and Hatch, M. R., 1995, “Analysis of Coupled Journal and Thrust Hydrodynamic Bearing Using a Finite-Volume Method,” Advances in Information Storage and Processing Systems, ISPS-Vol. 1, pp. 71–79.
10.
Rahman, M., and Leuthold, H., 2001, “Computer Simulation of a Coupled Journal and Thrust Hydrodynamic Bearing Using a Finite-Element Method,” Proc. International Tribology Conference Nagasaki, 2000, K. Ichimaru et al., eds., JST, Tokyo, III, pp. 1639–1644.
11.
Wang
,
Y.
,
Wang
,
Q. J.
, and
Lin
,
C.
,
2003
, “
Mixed Lubrication of Coupled Journal-Thrust-Bearing Systems Including Mass Conserving Cavitation
,”
ASME J. Tribol.
,
125
, pp.
747
–
755
.
12.
Hori, Y., and Okoshi, K., 1976, “Stability of a Rotating Shaft Supported by Porous Bearings,” Proc. JSLE-ASLE International Lubrication Conference, 1975, T. Sakurai, ed., Elsevier, Amsterdam, pp. 333–340.
13.
Kaneko
,
S.
,
Hashimoto
,
Y.
, and
I
,
H.
,
1997
, “
Analysis of Oil–Film Pressure Distribution in Porous Journal Bearings Under Hydrodynamic Lubrication Conditions Using an Improved Boundary Condition
,”
ASME J. Tribol.
,
119
, pp.
171
–
178
.
14.
Meurisse
,
M.-H.
, and
Giudicelli
,
B.
,
1999
, “
A 3D Conservative Model for Self-Lubricated Porous Journal Bearings in a Hydrodynamic Steady State
,”
ASME J. Tribol.
,
121
, pp.
529
–
537
.
15.
Vohr
,
J. H.
, and
Chow
,
C. Y.
,
1965
, “
Characteristics of Herringbone-Grooved Gas-Lubricated Journal Bearings
,”
ASME J. Basic Eng.
,
87
, pp.
568
–
578
.
16.
Hamrock, B. J., 1994, Fundamentals of Fluid Film Lubrication, McGraw-Hill, New York.
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