A fixed geometry hybrid thrust bearing is investigated with three different supply
orifice diameters. 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 thrust bearing. The rotor is supported radially
by two water-lubricated fluid film journal bearings and is attached to a 30,600 rpm
motor via a high speed coupling with very low axial stiffness. Thrust bearings with
three different orifice diameters (1.63, 1.80, and 1.93 mm) are tested for a range of
supply pressures, fluid film thicknesses, and rotational speeds. The water-lubricated test
bearings have eight pockets, with feed orifices located centrally in each pocket.
Experimental results are comparted to predictions found using bulk flow model
HYDROTHRUST.
Analysis of the data reveals generally good agreements between predictions and
measurements. 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. The largest orifice diameter configuration does not display
higher recess pressure ratios or operating clearances at high speeds for some supply
pressures, but it does continue to require additional lubricant flow rate compared to the
smaller orifice bearings. In these cases, the results are not reflected in predictions, which
otherwise correlate very well with experimental measurements. Estimations of static
loading axial stiffness are obtained using experimental results.
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.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2010-05-8002 |
| Date | 2010 May 1900 |
| Creators | Esser, Paul R. |
| Contributors | Childs, Dara W. |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | thesis, text |
| Format | application/pdf |
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