In rotating equipment, thrust bearings aid to balance axial loads and control shaft position. In turbomachinery, axial loads depend on shaft speed and pressure rise/drop on the impellers. This paper details a water-lubricated test rig for measurement of the performance of hydrostatic thrust bearings (HTBs). The rig contains two water-lubricated HTBs (105 mm outer diameter (OD)), one is the test bearing and the other a slave bearing. Both bearings face the outer side of thrust collars of a rotor. The paper shows measurements of HTB axial clearance, flow rate, and recess pressure for operation with increasing static load (max. 1.4 bar) and supply pressure (max. 4.14 bar) at a rotor speed of 3 krpm (12 m/s OD speed). Severe angular misalignment, static and dynamic, of the bearing surface against its collar persisted and affected all measurements. The HTB axial clearance increases as the supply pressure increases and decreases quickly as the applied load increases. The reduction in clearance increases the flow resistance across the film lands, thus reducing the through flow rate with an increase in recess pressure. In addition, an estimated bearing axial stiffness increases as the operating clearance decreases and as the supply pressure increases. Predictions from a bulk flow model qualitatively agree with the measurements. Alas they are not accurate enough. The differences likely stem from the inordinate tilts (static and dynamic) as well as the flow condition. The test HTB operates in a flow regime that spans from laminar to incipient turbulent. Quantification of misalignment at all operating conditions is presently a routine practice during operation of the test rig.

References

References
1.
Norbin
,
C.
,
Childs
,
D.
, and
Phillips
,
S.
,
2016
, “
Including Housing-Casing Fluid in a Lateral Rotordynamics Analysis on Electric Submersible Pumps
,”
ASME
Paper No. GT 2016-58087.
2.
Sternlicht
,
B.
, and
Elwell
,
R. C.
,
1960
, “
Theoretical and Experimental Analysis of Hydrostatic Thrust Bearings
,”
ASME J. Basic Eng.
,
82
(
3
), pp.
505
512
.
3.
Rowe
,
W.
,
1983
,
Hydrostatic and Hybrid Bearing Design
,
Butterworths
,
London
, pp.
1
20
.
4.
San Andrés
,
L.
,
2000
, “
Bulk-Flow Analysis of Hybrid Thrust Bearings for Process Fluid Applications
,”
ASME J. Tribol.
,
122
(
1
), pp.
170
180
.
5.
San Andrés
,
L.
,
2002
, “
Effects of Misalignment on Turbulent Flow Hybrid Thrust Bearings
,”
ASME J. Tribol.
,
124
(
1
), pp.
212
219
.
6.
Osman
,
T. A.
,
Dorid
,
M.
,
Safar
,
Z. S.
, and
Mokhtar
,
M. O. A.
,
1996
, “
Experimental Assessment of Hydrostatic Thrust Bearing Performance
,”
Tribol. Int.
,
29
(
3
), pp.
233
239
.
7.
Coombs
,
J. A.
, and
Dowson
,
D.
,
1964
, “
An Experimental Investigation of the Effects of Lubricant Inertia in a Hydrostatic Thrust Bearing
,”
Proc. Inst. Mech. Eng.
,
179
(
3
), pp.
96
114
.
8.
Wang
,
X.
, and
Yamaguchi
,
A.
,
2002
, “
Characteristics of Hydrostatic Bearing/Seal Parts for Water Hydraulic Pumps and Motors—Part 1: Experiment and Theory
,”
Tribol. Int.
,
35
(7), pp.
425
433
.
9.
Glavatskih
,
S. B.
,
2002
, “
Laboratory Research Facility for Testing Hydrodynamic Thrust Bearings
,”
Proc. Inst. Mech. Eng., Part J: J. Eng. Tribol.
,
216
(
2
), pp.
105
116
.
10.
Gregory
,
R. S.
,
1974
, “
Performance of Thrust Bearings at High Operating Speeds
,”
ASME J. of Lubrication Tech.
,
96
(
1
), pp.
7
13
.
11.
Belforte
,
G.
,
Colombo
,
F.
,
Raparelli
,
T.
,
Trivella
,
A.
, and
Viktorov
,
V.
,
2010
, “
Performance of Externally Pressurized Grooved Thrust Bearings
,”
Tribol. Lett.
,
37
(3), pp.
553
562
.
12.
Belforte
,
G.
,
Colombo
,
F.
,
Raparelli
,
T.
,
Trivella
,
A.
, and
Viktorov
,
V.
,
2011
, “
Comparison Between Grooved and Plan Aerostatic Thrust Bearings: Static Performance
,”
Meccanica
,
46
(3), pp.
547
555
.
13.
Forsberg
,
M.
,
2008
, “
Comparison Between Predictions and Experimental Measurements for an Eight Pocket Annular HTB
,” M.S. thesis, Texas A&M University, College Station, TX.
14.
Ramirez
,
F.
,
2008
, “
Comparison between Predictions and Measurements of Performance Characteristics for an Eight Pocket Hybrid (Combination Hydrostatic/Hydrodynamic) Thrust Bearing
,” M.S. thesis, Texas A&M University, College Station, TX.
15.
Esser
,
P.
,
2010
, “
Measurements Versus Predictions for a Hybrid (Hydrostatic plus Hydrodynamic) Thrust Bearing for a Range of Orifice Diameters
,” M.S. thesis, Texas A&M University, College Station, TX.
16.
Childs
,
D.
, and
Esser
,
P.
,
2016
, “
Measurements versus Predictions for a Hybrid (Hydrostatic plus Hydrodynamic) Thrust Bearing for a Range of Orifice Diameters
,”
ASME
Paper No. GT 2016-56213.
17.
San Andrés
,
L.
,
Phillips
,
S.
, and
Childs
,
D.
,
2016
, “
A Water Lubricated Hybrid Thrust Bearing: Measurements and Predictions of Static Load Performance
,”
ASME J. Eng. Gas Turbines Power
,
139
(
2
), p.
022506
.
18.
San Andrés
,
L.
,
2006
, “
Hybrid Flexure Pivot-Tilting Pad Gas Bearings: Analysis and Experimental Validation
,”
ASME J. Tribol.
,
128
(
3
), pp.
551
558
.
19.
Rohmer
,
M.
,
2015
, “
A Test Rig to Measure the Static Load Performance of a Water Lubricated Thrust Bearing
,”
M.S. thesis
, Texas A&M University, College Station, TX.
20.
Constantinescu
,
V. N.
,
1962
, “
Analysis of Bearings Operating in the Turbulent Regime
,”
ASME J. Basic Eng.
,
84
(1), pp.
139
151
.
You do not currently have access to this content.