Post on 16-Mar-2018
transcript
February 2005
1
(c) 2006, Pioneer Motor Bearing Company
Fluid Film Thrust Bearings:Fluid Film Thrust Bearings:Fundamentals, Damage Fundamentals, Damage
Evaluation, & RepairEvaluation, & Repair
Pioneer Motor BearingPioneer Motor BearingMay 2006May 2006
VIBRATION INSTITUTE MEETINGVIBRATION INSTITUTE MEETINGCHARLOTTE, NCCHARLOTTE, NC
(c) 2006, Pioneer Motor Bearing Company Slide Slide 22
OutlineOutlinennBasic Design CriteriaBasic Design CriteriannThrust Bearing MonitoringThrust Bearing MonitoringnnDamage investigationDamage investigationnnDamage mechanismsDamage mechanismsnn InspectionInspectionnnRepairRepair
(c) 2006, Pioneer Motor Bearing Company Slide Slide 33
HistoryHistorynnWithout question Without question
the most the most significant significant mechanical mechanical invention in the invention in the world was:world was:
The The WheelWheel
(c) 2006, Pioneer Motor Bearing Company Slide Slide 44
HistoryHistorynn However, almost However, almost
immediately upon immediately upon discovery of the discovery of the wheel, the need wheel, the need for bearings was for bearings was also discovered:also discovered:
(c) 2006, Pioneer Motor Bearing Company Slide Slide 55
HistoryHistorynnWhich has Which has
led to one led to one of the most of the most elusive elusive searches in searches in human human historyhistory
(c) 2006, Pioneer Motor Bearing Company Slide Slide 66
HistoryHistorynn As one can As one can
observe from this observe from this wooden wheel wooden wheel dating to 2700 dating to 2700 BC, axels where BC, axels where used to allow used to allow support by radial support by radial and thrust and thrust bearings:bearings:
February 2005
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(c) 2006, Pioneer Motor Bearing Company Slide Slide 77
Load Orientations: Load Orientations: radial/thrustradial/thrust
Slide Slide 88
Thrust BearingThrust BearingnnSupport axial load from the processSupport axial load from the processnne.g. Water or steam pressuree.g. Water or steam pressure
nnThrust runner surfaceThrust runner surfacennGenerally flat Generally flat (<13 (<13 µµm = 0.0005m = 0.0005””))nn 16 16 µµin RMSin RMS
nnThrust bearingThrust bearingnnGenerally circumferential segmentsGenerally circumferential segments
nnTend to be Tend to be ““squaresquare”” -- length=widthlength=widthnnTradeTrade--offoff
nnLarger loaded area gives more friction lossLarger loaded area gives more friction loss
(c) 2006, Pioneer Motor Bearing Company Slide Slide 99
Thrust ClearanceThrust ClearancennTypical operating clearanceTypical operating clearance
Human hair aboutHuman hair about75 75 µµm (0.003m (0.003””) diameter) diameter
Typical operating clearance Typical operating clearance about 25 about 25 µµm (0.001m (0.001””).).
RUNNERRUNNER
BEARINGBEARING
Ref: ROTECHRef: ROTECH
(c) 2006, Pioneer Motor Bearing Company Slide Slide 1010
Thrust LoadThrust Loadnn Load capacity based onLoad capacity based on
nnHydrodynamic pressure profileHydrodynamic pressure profilenn Pad areaPad area
nn NominallyNominallynn Reduced by grooving Reduced by grooving
( )22**25.0 IDODArea −= π
(c) 2006, Pioneer Motor Bearing Company Slide Slide 1111
Thrust Bearing DesignsThrust Bearing DesignsnnFlat WasherFlat WashernnFlat Flat BabbittedBabbitted Face With GroovesFace With GroovesnnTaperTaper--Land Land BabbittedBabbitted FaceFacennTilting Pad Thrust BearingTilting Pad Thrust BearingnnEqualized Tilting Pad Thrust Equalized Tilting Pad Thrust
BearingBearing
(c) 2006, Pioneer Motor Bearing Company Slide Slide 1212
Flat WashersFlat Washersnn Simple but useful Simple but useful
only with minimal only with minimal speed and load speed and load conditionsconditions
nn Grease lubricated Grease lubricated
February 2005
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(c) 2006, Pioneer Motor Bearing Company Slide Slide 1313
““BumperBumper”” ThrustThrust
BabbittedBabbitted axial surfaces to resist motion of shaft collars.axial surfaces to resist motion of shaft collars.BabbittedBabbitted surface may have radial pockets or grooving.surface may have radial pockets or grooving.
(c) 2006, Pioneer Motor Bearing Company Slide Slide 1414
Flat Flat BabbittedBabbitted Thrust Face Thrust Face with Grooveswith Grooves
nn Useful as a bumper, Useful as a bumper, or locating bearingor locating bearing
nn Oil or grease Oil or grease lubricatedlubricated
nn No theoretical load No theoretical load capacitycapacity
nn Practical capacity Practical capacity around 50 to 75 PSIaround 50 to 75 PSI
(c) 2006, Pioneer Motor Bearing Company Slide Slide 1515
““BumperBumper”” ThrustThrustRadial Radial grooves grooves enhance load enhance load capacity.capacity.
(c) 2006, Pioneer Motor Bearing Company Slide Slide 1616
TaperTaper--Land Thrust BearingLand Thrust Bearing
nn Optimized for only Optimized for only one speed and load one speed and load combinationcombination
nn Taper for oil wedge Taper for oil wedge formation is formation is machined into the machined into the bearing surfacebearing surface
nn Alignment is critical Alignment is critical to operationto operation
nn Practical load limit Practical load limit 150 to 225 PSI150 to 225 PSI
(c) 2006, Pioneer Motor Bearing Company Slide Slide 1717
Simple TaperedSimple Tapered--Land ThrustLand Thrust
(c) 2006, Pioneer Motor Bearing Company Slide Slide 1818
Compound TaperedCompound Tapered--Land ThrustLand ThrustTaper is steeper Taper is steeper at the inner at the inner diameter than diameter than at the outer at the outer diameter. diameter. Taper is Taper is generally generally 0.0030.003””--0.0070.007””. . Land region is Land region is visible.visible.
February 2005
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(c) 2006, Pioneer Motor Bearing Company Slide Slide 1919
FluidFluid--film Thrust Bearingfilm Thrust BearingnnAnnulus controls axial position.Annulus controls axial position.nnMaximum load capacityMaximum load capacity
TiltingTilting--padpadbearingbearing
(c) 2006, Pioneer Motor Bearing Company Slide Slide 2020
Tilting Pad Thrust BearingTilting Pad Thrust Bearingnn Self Optimizing based Self Optimizing based
on applied load and on applied load and speedspeed
nn Maximum Flexibility Maximum Flexibility re: potential re: potential modificationsmodifications
nn Alignment is criticalAlignment is criticalnn Load Capacity in Load Capacity in
excess of 600 PSIexcess of 600 PSI
(c) 2006, Pioneer Motor Bearing Company Slide Slide 2121
Tilting Pad Thrust BearingsTilting Pad Thrust Bearings
Equalizing linkages correct for housing skew.Equalizing linkages correct for housing skew.Equalizing linkages do not correct for rotating collar skew.Equalizing linkages do not correct for rotating collar skew.
Ref: Kingsbury literatureRef: Kingsbury literature
(c) 2006, Pioneer Motor Bearing Company Slide Slide 2222
NonNon--Equalizing SupportEqualizing Support
Ref: Constantinescu, p. 354.Ref: Constantinescu, p. 354.
(c) 2006, Pioneer Motor Bearing Company Slide Slide 2323
NonNon--Equalized BearingEqualized Bearing
(c) 2006, Pioneer Motor Bearing Company Slide Slide 2424
Self Equalizing Tilting Pad Self Equalizing Tilting Pad Thrust BearingsThrust Bearingsnn Maximum capacity in Maximum capacity in
given spacegiven spacenn Self optimizing oil Self optimizing oil
filmfilmnn Can accommodate Can accommodate
collar to housing collar to housing misalignmentmisalignment
nn Not designed for Not designed for dynamic dynamic misalignmentmisalignment
nn Load Capacity in Load Capacity in excess of 600 PSIexcess of 600 PSI
February 2005
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(c) 2006, Pioneer Motor Bearing Company Slide Slide 2525
Equalizing LinkagesEqualizing Linkages
Ref: Constantinescu, p. 354.Ref: Constantinescu, p. 354.
Intent is to Intent is to equally load equally load each of the each of the thrust pads in thrust pads in spite of spite of variations in variations in pad thickness or pad thickness or misalignment of misalignment of the housing to the housing to the runner.the runner.
(c) 2006, Pioneer Motor Bearing Company Slide Slide 2626
AntiAnti--Rotation PinsRotation PinsProvides:Provides:
Locates shell in housingLocates shell in housing••CircumferentialCircumferential
Prevent rotation of the cage Prevent rotation of the cage in the housing.in the housing.
(c) 2006, Pioneer Motor Bearing Company Slide Slide 2727
Combined Journal ThrustCombined Journal Thrust
Lobed journal Lobed journal bearingbearing
Tapered thrust Tapered thrust bearingbearing
(c) 2006, Pioneer Motor Bearing Company Slide Slide 2828
Oil Distribution GeometryOil Distribution Geometry
OIL INLET OIL INLET HOLEHOLE
Radial grooveRadial groove
Axial grooveAxial grooveBleederBleeder
BleedersBleeders
Spreader
Groove
Spreader
Groove
(c) 2006, Pioneer Motor Bearing Company Slide Slide 2929
Thrust Bearing FlowsThrust Bearing Flows
Ref. Kingsbury Ref. Kingsbury sales literature, sales literature, EQHEQH--1.1.
Rotation
Rotation
(c) 2006, Pioneer Motor Bearing Company Slide Slide 3030
Tilting Pad Thrust BearingsTilting Pad Thrust Bearings
Ref: Kingsbury literatureRef: Kingsbury literature
February 2005
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(c) 2006, Pioneer Motor Bearing Company Slide Slide 3131
So, how much load can So, how much load can mymybearing take?bearing take?nn This depends This depends
on where you on where you are operating are operating within the within the regime of the regime of the bearing bearing performance performance parametersparameters
nn No, I am not a No, I am not a lawyerlawyer
(c) 2006, Pioneer Motor Bearing Company Slide Slide 3232
What can be done to What can be done to increase load capacity?increase load capacity?nnFirst, understand the shortcomings First, understand the shortcomings
of the existing bearingof the existing bearingnnSecond, consider modifications to Second, consider modifications to
the operating parametersthe operating parametersnnThird, consider an upgrade to the Third, consider an upgrade to the
basic bearing designbasic bearing design
(c) 2006, Pioneer Motor Bearing Company Slide Slide 3333
Deal with low speed wearDeal with low speed wearnn Hydrostatic lift system to provide Hydrostatic lift system to provide
hydrostatic oil films where hydrodynamic hydrostatic oil films where hydrodynamic oil films may not otherwise be presentoil films may not otherwise be presentnn Start up operationStart up operationnn Turning gear operationTurning gear operationnn Some emergency conditionsSome emergency conditionsnn Per DIN 31652 part 3 consider hydrostatic lift Per DIN 31652 part 3 consider hydrostatic lift
where startup loads exceed 2.5where startup loads exceed 2.5--3.0 3.0 MPaMPa(363(363--435 435 psipsi))nn May be required for lower loadsMay be required for lower loads
(c) 2006, Pioneer Motor Bearing Company Slide Slide 3434
Hydrostatic Lift SystemsHydrostatic Lift Systemsnn Inject high pressure oil (typically > Inject high pressure oil (typically >
1000 1000 psipsi) at the location of the ) at the location of the highest loadinghighest loading
nnHydrostatic film is developed Hydrostatic film is developed through pressure, film thickness is through pressure, film thickness is controlled by flowcontrolled by flow
nnQuite often, many bearings are fed Quite often, many bearings are fed by a common high pressure headerby a common high pressure header
(c) 2006, Pioneer Motor Bearing Company Slide Slide 3535
Hydrostatic Lift SystemHydrostatic Lift Systemnn Introduce externallyIntroduce externally--pressurized oil pressurized oil
into bearing cavity for operation at into bearing cavity for operation at low surface speeds and high loadslow surface speeds and high loadsnn Forms hydrostatic bearing on lower halfForms hydrostatic bearing on lower half
(c) 2006, Pioneer Motor Bearing Company Slide Slide 3636
Hydrostatic Lift SystemHydrostatic Lift System
Hydrostatic lift in tilting pad thrust shoes.Hydrostatic lift in tilting pad thrust shoes.
February 2005
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(c) 2006, Pioneer Motor Bearing Company Slide Slide 3737
Main oil pump is shaft drivenMain oil pump is shaft driven
AC & DC pumpsAC & DC pumps
Sample Hydrostatic Lift Oil SystemSample Hydrostatic Lift Oil System
Schematic of Schematic of TurbineTurbine--Generator Generator Hydrostatic Hydrostatic Lift SystemLift System
Each radial bearing #3Each radial bearing #3--8 has a 8 has a separate pressurized hydrostaticseparate pressurized hydrostatic--lift supply (1500 psig), separate lift supply (1500 psig), separate supply pump with a gravity (or supply pump with a gravity (or slight vacuum) drain back to the slight vacuum) drain back to the reservoir.reservoir.
(c) 2006, Pioneer Motor Bearing Company Slide Slide 3838
OK smart guy, IOK smart guy, I’’ve already got ve already got a tilting pad thrust bearing, a tilting pad thrust bearing, Now what?Now what?nnConsider upgrading specific design Consider upgrading specific design
features of the assemblyfeatures of the assemblynnDirected lubricationDirected lubricationnnAlternative materialsAlternative materialsnnOffset pivotsOffset pivots
(c) 2006, Pioneer Motor Bearing Company Slide Slide 3939
Effect of Pivot OffsetEffect of Pivot Offset
(c) 2006, Pioneer Motor Bearing Company Slide Slide 4040
Effect of ChromeEffect of Chrome--Copper Alloy Copper Alloy Backing MaterialBacking Material
(c) 2006, Pioneer Motor Bearing Company Slide Slide 4141
Thrust Bearing MonitoringThrust Bearing MonitoringnnTemperatureTemperaturennLoadLoadnnThrust Collar PositionThrust Collar Position
(c) 2006, Pioneer Motor Bearing Company Slide Slide 4242
Thrust Temperature Thrust Temperature MonitoringMonitoring
nnEmbedded SensorsEmbedded SensorsnnThermocouplesThermocouplesnnRTDRTD’’ss
nnOil Inlet and Exit TemperatureOil Inlet and Exit Temperature
February 2005
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(c) 2006, Pioneer Motor Bearing Company Slide Slide 4343
TiltTilt--Pad Thrust ProfilesPad Thrust Profiles
Ref. Kingsbury Ref. Kingsbury sales literature, sales literature, EQHEQH--1.1.
Temperature profiles Temperature profiles show influence of show influence of pressure peak over the pressure peak over the pivot (dashed circle), as pivot (dashed circle), as well as radial and well as radial and circumferential flow.circumferential flow.
(c) 2006, Pioneer Motor Bearing Company Slide Slide 4444
Embedded SensorsEmbedded Sensorsnn Proper LocationProper Location
(c) 2006, Pioneer Motor Bearing Company Slide Slide 4545
Thrust Load MeasurementThrust Load Measurementnn Basic Bearing Basic Bearing
DesignDesign
(c) 2006, Pioneer Motor Bearing Company Slide Slide 4646
Thrust Load MeasurementThrust Load Measurementnn Leveling PlatesLeveling Plates
(c) 2006, Pioneer Motor Bearing Company Slide Slide 4747
Thrust Load MeasurementThrust Load Measurementnn Strain Strain
Gage Gage Load CellLoad Cell
(c) 2006, Pioneer Motor Bearing Company Slide Slide 4848
Thrust Position MeasurementThrust Position MeasurementnnEddy Current ProbesEddy Current ProbesnnDual VotingDual Voting
February 2005
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(c) 2006, Pioneer Motor Bearing Company Slide Slide 4949
Thrust Position MeasurementThrust Position Measurement
(c) 2006, Pioneer Motor Bearing Company Slide Slide 5050
Damage InvestigationDamage Investigation
nnGeneric ElementsGeneric ElementsnnVisual examinationVisual examinationnnBackground informationBackground informationnnPhotographic recordsPhotographic recordsnnEvent reconstructionEvent reconstructionnnLaboratory analysisLaboratory analysis
(c) 2006, Pioneer Motor Bearing Company Slide Slide 5151
Damage InvestigationDamage Investigationnn Visual Visual
ExaminationExamination
““Say, is all that Say, is all that babbitt supposed babbitt supposed to be on the to be on the bottom of the bottom of the bearing housing bearing housing like that?like that?””
(c) 2006, Pioneer Motor Bearing Company Slide Slide 5252
Damage InvestigationDamage Investigation
nnGeneric ElementsGeneric ElementsnnVisual examinationVisual examinationnnBackground informationBackground informationnnPhotographic recordsPhotographic recordsnnEvent reconstructionEvent reconstructionnnLaboratory analysisLaboratory analysis
(c) 2006, Pioneer Motor Bearing Company Slide Slide 5353
Visual ExaminationVisual Examination
(c) 2006, Pioneer Motor Bearing Company Slide Slide 5454
Where is the damage?Where is the damage?nnBabbitt SurfaceBabbitt SurfacennCentered over pivotCentered over pivotnnMore toward trailing edgeMore toward trailing edgennMore toward leading edgeMore toward leading edge
nnSupporting structureSupporting structurennLeveling platesLeveling plates
nnThrust collarThrust collar
February 2005
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(c) 2006, Pioneer Motor Bearing Company Slide Slide 5555
Babbitt Surface DamageBabbitt Surface Damage
Damage located primarily along the trailing edge is indicative oDamage located primarily along the trailing edge is indicative of debris,f debris,electrolysis, or other trauma that occurred while the bearing waelectrolysis, or other trauma that occurred while the bearing was s otherwise operating in a normal condition otherwise operating in a normal condition
(c) 2006, Pioneer Motor Bearing Company Slide Slide 5656
Babbitt Surface DamageBabbitt Surface Damage
Damage located primarily opposite the pivot is indicative the beDamage located primarily opposite the pivot is indicative the bearing aring operating in an overloaded condition operating in an overloaded condition
(c) 2006, Pioneer Motor Bearing Company Slide Slide 5757
Babbitt Surface DamageBabbitt Surface Damage
Damage located primarily along the leading edge is indicative ofDamage located primarily along the leading edge is indicative of a lack a lack of lubrication, either during start up, or during operation of lubrication, either during start up, or during operation
(c) 2006, Pioneer Motor Bearing Company Slide Slide 5858
Support Structure DamageSupport Structure DamagennDamage to the leveling plates, base Damage to the leveling plates, base
ring, or other support structure is ring, or other support structure is usually indicative of thrust collar usually indicative of thrust collar runoutrunout problemsproblems
nnCollar may be installed improperly, Collar may be installed improperly, or may have come loose in serviceor may have come loose in service
(c) 2006, Pioneer Motor Bearing Company Slide Slide 5959
Collar DamageCollar DamagennCircumferential scoring or Circumferential scoring or
scratching of the thrust collar is scratching of the thrust collar is usually indicative of debris in the oil usually indicative of debris in the oil systemsystem
(c) 2006, Pioneer Motor Bearing Company Slide Slide 6060
Damage MechanismsDamage MechanismsnnMechanisms are the same as those Mechanisms are the same as those
covered earlier by Dr. Branagancovered earlier by Dr. BranagannnSpecific thrust bearing photographs Specific thrust bearing photographs
may help may help
February 2005
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(c) 2006, Pioneer Motor Bearing Company Slide Slide 6161
Minor OverloadMinor Overload
(c) 2006, Pioneer Motor Bearing Company Slide Slide 6262
Babbitt FatigueBabbitt Fatigue
(c) 2006, Pioneer Motor Bearing Company Slide Slide 6363
OverheatingOverheating
(c) 2006, Pioneer Motor Bearing Company Slide Slide 6464
Gross OverheatingGross Overheating
(c) 2006, Pioneer Motor Bearing Company Slide Slide 6565
AnisotropyAnisotropy
(c) 2006, Pioneer Motor Bearing Company Slide Slide 6666
Tin / Copper MigrationTin / Copper Migration
February 2005
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(c) 2006, Pioneer Motor Bearing Company Slide Slide 6767
Pivot FrettingPivot Fretting
(c) 2006, Pioneer Motor Bearing Company Slide Slide 6868
Leveling Plate FrettingLeveling Plate Fretting
(c) 2006, Pioneer Motor Bearing Company Slide Slide 6969
Babbitt ErosionBabbitt Erosion
(c) 2006, Pioneer Motor Bearing Company Slide Slide 7070
Bearing InspectionBearing InspectionnnBearing SurfaceBearing SurfacennBearing SubsurfaceBearing SubsurfacennThrust CollarThrust CollarnnAssembled End PlayAssembled End Play
(c) 2006, Pioneer Motor Bearing Company Slide Slide 7171
Thrust Bearing SurfaceThrust Bearing SurfacennPortion of bearing designed to carry Portion of bearing designed to carry
the load must be clean and flatthe load must be clean and flatnn Inspect for embedded debris with a Inspect for embedded debris with a
single edged razor bladesingle edged razor bladenn Inspect surface with straight edgeInspect surface with straight edgenn Inspect contact with Prussian Inspect contact with Prussian
bluing with a calibrated plate and bluing with a calibrated plate and finally with the mating thrust collarfinally with the mating thrust collar
(c) 2006, Pioneer Motor Bearing Company Slide Slide 7272
Thrust Bearing SubsurfaceThrust Bearing SubsurfacennUltrasonic InspectionUltrasonic InspectionnnDye Pen InspectionDye Pen InspectionnnBrass Dowel Ring TestBrass Dowel Ring Test
February 2005
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(c) 2006, Pioneer Motor Bearing Company Slide Slide 7373
Thrust Collar InspectionThrust Collar InspectionnnSurface finish 16 RMS or betterSurface finish 16 RMS or betternnSurface flatness less than .001 inchSurface flatness less than .001 inchnnAssembled Assembled runoutrunout less than .001 less than .001
TIRTIR
(c) 2006, Pioneer Motor Bearing Company Slide Slide 7474
Assembled Assembled RunoutRunout CheckChecknnCan not be measured with a single Can not be measured with a single
indicator as rotor float will impact indicator as rotor float will impact measurementmeasurement
nnTemporary blocking may be Temporary blocking may be required to limit rotor float during required to limit rotor float during inspectioninspection
nnRequires 2 Requires 2 MagMag base indicators with base indicators with sufficient travel to stay in contact sufficient travel to stay in contact with collar facewith collar face
(c) 2006, Pioneer Motor Bearing Company Slide Slide 7575
Indicator positionIndicator position
(c) 2006, Pioneer Motor Bearing Company Slide Slide 7676
Typical Measurement recordTypical Measurement record
0.00100.00200.0030360
0.0000-0.0010-0.0010315
-0.0010-0.0010-0.0020270
-0.00200.00250.0005225
-0.00100.00200.0010180
0.00000.00300.0030135
0.00100.00500.006090
0.0020-0.00050.001545
0.0010-0.00100.00000
A-BBARotation
Column of calculated AColumn of calculated A--B values gives twice the B values gives twice the TIR TIR runoutrunout readings for the thrust collar. In readings for the thrust collar. In this example, the collar is running out .002 TIR this example, the collar is running out .002 TIR
(c) 2006, Pioneer Motor Bearing Company Slide Slide 7777
Assembled End PlayAssembled End PlaynnBest to first measure available Best to first measure available
space and stacked height of the space and stacked height of the bearing assembliesbearing assemblies
nnDifference should be the assembled Difference should be the assembled end playend play
nnAfter assembly, bump test the rotor After assembly, bump test the rotor to confirm measurementto confirm measurement
(c) 2006, Pioneer Motor Bearing Company Slide Slide 7878
RepairsRepairsnnMany minor thrust bearing repairs Many minor thrust bearing repairs
can be accomplished on sitecan be accomplished on sitennThe level of repair that should be The level of repair that should be
attempted is directly proportional to attempted is directly proportional to the experience level of the the experience level of the technicians availabletechnicians available
February 2005
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(c) 2006, Pioneer Motor Bearing Company Slide Slide 7979
Babbitt Surface RepairsBabbitt Surface Repairsnn Minor imperfections Minor imperfections
can be removed by can be removed by lapping or scrapinglapping or scraping
nn Larger scratches can Larger scratches can be repaired by first be repaired by first locally locally puddlingpuddlingbabbitt and followed babbitt and followed by by peeningpeening and then and then lapping or scrapinglapping or scraping
(c) 2006, Pioneer Motor Bearing Company Slide Slide 8080
Babbitt Babbitt PuddlingPuddling
(c) 2006, Pioneer Motor Bearing Company Slide Slide 8181
Hand ScrapingHand Scraping
(c) 2006, Pioneer Motor Bearing Company Slide Slide 8282
Power ScrapingPower Scraping
(c) 2006, Pioneer Motor Bearing Company Slide Slide 8383
Thrust Collar RepairThrust Collar RepairnnMinor damage and glazing can be Minor damage and glazing can be
repaired by hand stoningrepaired by hand stoningnnUse a fine 600 grit oil stoneUse a fine 600 grit oil stonennMore serious repairs can be More serious repairs can be
corrected by turning, lapping, or corrected by turning, lapping, or grindinggrinding
nnMany of these operations can be Many of these operations can be conducted in placeconducted in place
(c) 2006, Pioneer Motor Bearing Company Slide Slide 8484
ConclusionsConclusionsnnRemember that that the babbitt Remember that that the babbitt
surface is a SOFT, sacrificial layer.surface is a SOFT, sacrificial layer.nnLook at your babbitt surface to Look at your babbitt surface to
better understand the likely cause better understand the likely cause of the bearing damage and reduce of the bearing damage and reduce rere--occurrence.occurrence.
nnRemanufacture (repair) or redesign Remanufacture (repair) or redesign bearing depending on the nature, bearing depending on the nature, severity, and probability of future severity, and probability of future damage.damage.