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Research Papers

Measurements Versus Predictions for a Hybrid (Hydrostatic Plus Hydrodynamic) Thrust Bearing for a Range of Orifice Diameters

[+] Author and Article Information
Dara W. Childs

Leland T. Jordan Professor of Mechanical
Engineering,
Turbomachinery Laboratory Texas A&M
University,
College Station, TX 77845

Paul Esser

M.S. Mechanical Engineering,
Texas A&M University,
College Station, TX 77845

Manuscript received July 3, 2018; final manuscript received January 15, 2019; published online February 21, 2019. Editor: Jerzy T. Sawicki.

J. Eng. Gas Turbines Power 141(6), 061015 (Feb 21, 2019) (12 pages) Paper No: GTP-18-1432; doi: 10.1115/1.4042721 History: Received July 03, 2018; Revised January 15, 2019

A fixed-geometry hybrid thrust bearing is investigated with three different supply orifice diameters, (1.63, 1.80, and 1.93 mm). The test rig uses a face-to-face thrust-bearing design, with the test bearing acting as the rotor loading mechanism. A hydraulic shaker applies the static axial load, which is reacted by a second (slave) thrust bearing. The rotor is supported radially by two water-lubricated fluid-film journal bearings and is attached to a 30.6 krpm motor via a high-speed coupling with very low axial stiffness. Thrust bearings are tested for a range of supply pressures (5.17, 10.34, and 17.34 bars), fluid film thicknesses, and speeds (7.5, 12.5, and 17.5 krpm). The water-lubricated test bearings have eight pockets, with feed orifices located centrally in each pocket. Experimental results are compared to predictions from a bulk-flow model, showing generally good agreement. Thrust-bearing inlet supply and inner radius flow rates all decreased with decreasing orifice diameters and bearing axial clearances. In most cases, the bearings with larger orifice diameters exhibit higher recess pressure ratios, operating clearances, and flow rates. An optimum hybrid thrust-bearing orifice diameter will depend on the conditions of individual applications. Larger orifices generally provide larger operating clearances and higher stiffnesses, but also require higher flow rates. For most applications, a compromise of bearing performance parameters will be desired. The test results and comparisons presented will aid in sizing orifice diameters for future hybrid thrust-bearing designs and in validating and improving models and predictions.

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References

Minick, A. , and Peery, S. , 1998, “ Design and Development of an Advanced Liquid Hydrogen Turbopump,” AIAA Paper No. 1998-3681.
San Andrés, L. , 2000, “ Bulk-Flow Analysis of Hybrid Thrust Bearings for Process Fluid Applications,” ASME J. Tribol., 122(1), pp. 170–180. [CrossRef]
San Andrés, L. , 2002, “ Effects of Misalignment on Turbulent Flow Hybrid Thrust Bearings,” ASME J. Tribol., 124(1), pp. 212–219. [CrossRef]
Mosher, P. , and Childs, D. , 1998, “ Theory Versus Experiment for the Effects of Pressure Ratio on the Performance of an Orifice-Compensated Hybrid Bearing,” ASME J. Vib. Acoust., 120(4), pp. 930–936. [CrossRef]
Pinkus, O. , and Lund, J. W. , 1981, “ Centrifugal Effects in Thrust Bearings and Seals Under Laminar Conditions,” ASME J. Lubr. Technol., 103(1), pp. 126–136.
Hashimoto, H. , 1990, “ The Effects of Fluid Inertia Forces on the Static Characteristics of Sector-Shaped High Speed Thrust Bearings in Turbulent Flow Regime,” ASME J. Tribol., 111(3), pp. 406–411. [CrossRef]
Safar, Z. S. , 1983, “ Centrifugal Effects in Misaligned Hydrostatic Thrust Bearings,” ASME J. Lubr. Technol., 105(4), pp. 621–624. [CrossRef]
New, N. H. , 1974, “ Experimental Comparison of Flooded, Directed, and Inlet Orifice Type of Lubrication for a Tilting Pad Thrust Bearing,” ASME J. Lubr. Technol., 96(1), pp. 22–27. [CrossRef]
Gregory, R. S. , 1977, “ Operating Characteristics of a Fluid Film Thrust Bearing Subjected to High Shaft Speeds,” Super Laminar Flow in Bearings, Mechanical Engineering Publications, Suffolk, UK.
Neal, P. B. , 1982, “ Heat Transfer in Pad Thrust Bearings,” Institution of Mechanical Engineers, London, UK, June 1, pp. 217–228.
Horner, D. , Simmons, J. E. L. , and Advani, S. D. , 1988, “ Measurements of Maximum Temperature in Tilting-Pad Thrust Bearings,” STLE Tribol. Trans., 31(1), pp. 44–53. [CrossRef]
Harada, M. , Miyaji, R. , and Anada, Y. , 1987, “ Turbulent Lubrication for a Hydrostatic Thrust Bearing With a Circular Recess: Vibration, Control Engineering, Engineering for Industry,” Bull. JSME, 30(269), pp. 1819–1825.
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. [CrossRef]
Gardner, W. W. , 1975, “ Performance Tests on Six-Inch Tilting Pad Thrust Bearings,” ASME J. Lubr. Technol., 97(3), pp. 460–438.
Glavatskih, S. B. , 2002, “ Laboratory Research Facility for Testing Hydrodynamic Thrust Bearings,” Proc. Inst. Mech. Eng., 216(2), pp. 105–116. [CrossRef]
Forsberg, M. , 2008, “ Comparison Between Predictions and Experimental Measurements for an Eight Pocket Annular Hydrostatic Thrust Bearing,” M.Sc. Project Report, Texas A&M University, College Station, TX, Report. https://apps.dtic.mil/dtic/tr/fulltext/u2/1001573.pdf
Ramirez, F. , 2008, “ Comparison Between Predictions and Measurements of Performance Characteristics for an Eight Pocket Hybrid (Combination Hydrostatic/Hydrodynamic) Thrust Bearing,” M.Sc. Project Report, Texas A&M University, College Station, TX.
San Andrés, L. , Rohmer, M. , and Park, S. , 2015, “ Failure of a Test Rig Operating With Pressurized Gas Bearings: A Lesson on Humility,” ASME Paper GT2015-42556.
Esser, P. , 2010, “ Measurements Versus Predictions for a Hybrid (Hydrostatic Plus Hydrodynamic) Thrust Bearing for a Range of Orifice Diameters,” M.S. thesis, Mechanical Engineering, Texas A&M University, College Station, TX.
San Andrés, L. , Phillips, S. , and Childs, D. , 2008, “ Static Load Performance of a Hybrid Thrust Bearing: Measurements and Validation of Predictive Tool,” Sixth Modeling and Simulation Subcommittee/Fourth Liquid Propulsion Subcommittee/Third Spacecraft Propulsion Subcommittee Joint Meeting, Orlando, FL, Dec. 8–12, Paper No. JANNAF-120 (Paper of Restricted Distribution—Joint Army, Navy, NASA, Air Force Interagency Propulsion Committee).
Coleman, H. W. , and Steele, G. W. , 1988, Experimentation and Uncertainty Analysis for Engineers, Wiley, New York.

Figures

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Fig. 1

Test thrust-bearing front and back

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Fig. 2

Test rig schematic

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Fig. 3

Test rig load path

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Fig. 4

Test thrust-bearing support pedestal and loading shaft

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Fig. 5

Test thrust-bearing water and air flow

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Fig. 6

Test thrust-bearing instrumentation [16]

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Fig. 7

Misalignment illustration and proximity probe locations on the test thrust bearing [16]

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Fig. 8

Misalignment over the bearing face about the x- and y-axes versus center clearance at 17.24 bar supply and 17.5 krpm. Lines note desired misalignment limits (±0.013 mm).

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Fig. 9

Measured and predicted inlet flow rate versus center clearance at 10.34 bar supply and 12.5 krpm

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Fig. 10

Measured and predicted inlet flow rate versus clearance at 17.24 bar supply and 7.5 krpm

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Fig. 11

Measured and predicted recess pressure ratio versus clearance at 10.34 bar supply and 12.5 krpm

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Fig. 12

Measured and predicted recess pressure ratio versus clearance at 17.24 bar supply and 7.5 krpm

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Fig. 13

Measured and predicted recess pressure ratio versus clearance at 5.17 bar supply and 17.5 krpm

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Fig. 14

Measured and predicted recess pressure ratio versus clearance at 17.24 bar supply and 12.5 krpm

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Fig. 15

Measured and predicted inner radius exhaust flow rate versus center clearance at 17.24 bar supply and 12.5 krpm

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Fig. 16

Measured and predicted inner radius exhaust flow rate versus center clearance at 10.34 bar supply and 12.5 krpm

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Fig. 17

Measured and predicted inner radius exhaust flow rate versus center clearance at 5.17 bar supply and 17.5 krpm

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Fig. 18

Measured and predicted center clearance versus load for 1.63 mm orifice bearing at 17.24 bar supply and 7.5 krpm

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Fig. 19

Measured and predicted center clearance versus load at 10.34 bar supply and 7.5 krpm

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Fig. 20

Measured and predicted center clearance versus load at 17.24 bar supply and 7.5 krpm

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Fig. 21

Measured and predicted center clearance versus load at 10.34 bar supply and 1.63 mm orifice diameters for all speeds

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Fig. 22

Estimated axial stiffness versus clearance at 10.34 bar supply and 7.5 krpm

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Fig. 23

Measured and predicted load versus center clearance at 10.34 bar supply and 7.5 krpm

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Fig. 24

Estimated axial stiffness versus clearance at 17.24 bar supply and 7.5 krpm

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