Engine Bearing Failure [SubsTech]

10
  to Metals to Engine bearings Engine bearing failure Dr. Dmi tri Kopeliovich Engine bearings are small and relatively inexpensive components of internal combustion engines however failure of an engine bear ing commonly leads to serious reconditioning works of the engine including its disassembling, regrindi ng the crankshaft and replacing the bearings. Factors affecting normal functioning of engine bearings: Properties of engine bearing materials: Fatigue strength (load capacity) Seizure resistance (compatibility) Wear resistance Conformability Embedability Corrosion resistance Cavitation resistance Bearings dimensions: Diameter Length Thickness Oil clearance Parameters of the internal combusti on engine, which determines functioning conditions of the bearings: The engine type (gasoline, diesel with direct fuel injection, diesel with indirect fuel injection). Compression ratio. Rotation speed. Aspiration type (naturally aspirated, turbocharged, supercharged). Combustion parameters. Lubrication system: Oil pressure and flow rate provided by the oil pump. Oil supply through the oil filter, oil passages and the bearings oil holes. Level of the oil contamination. Geometry imperfections and misalignment:

Transcript of Engine Bearing Failure [SubsTech]

  • 7/26/2015 Enginebearingfailure[SubsTech]

    http://www.substech.com/dokuwiki/doku.php?id=engine_bearing_failure 1/10

    toMetalstoEnginebearings

    Enginebearingfailure

    Dr.DmitriKopeliovich

    Enginebearingsaresmallandrelativelyinexpensivecomponentsofinternalcombustionengineshoweverfailureofanenginebearingcommonlyleadstoseriousreconditioningworksoftheengineincludingitsdisassembling,regrindingthecrankshaftandreplacingthebearings.

    Factorsaffectingnormalfunctioningofenginebearings:

    Propertiesofenginebearingmaterials:Fatiguestrength(loadcapacity)Seizureresistance(compatibility)WearresistanceConformabilityEmbedabilityCorrosionresistanceCavitationresistance

    Bearingsdimensions:DiameterLengthThicknessOilclearance

    Parametersoftheinternalcombustionengine,whichdeterminesfunctioningconditionsofthebearings:

    Theenginetype(gasoline,dieselwithdirectfuelinjection,dieselwithindirectfuelinjection).Compressionratio.Rotationspeed.Aspirationtype(naturallyaspirated,turbocharged,supercharged).Combustionparameters.

    Lubricationsystem:Oilpressureandflowrateprovidedbytheoilpump.Oilsupplythroughtheoilfilter,oilpassagesandthebearingsoilholes.Leveloftheoilcontamination.

    Geometryimperfectionsandmisalignment:

  • 7/26/2015 Enginebearingfailure[SubsTech]

    http://www.substech.com/dokuwiki/doku.php?id=engine_bearing_failure 2/10

    Excessiveorinsufficientbearingcrush.Bearingbacknonconformedtotheroundhousingbore.Improperlygroundhousingbore.Improperlygroundjournal(tapershape,barrelshape,hourglassshape).Excessivefilletofthejournal.Distortedconnectingrod.Distortedcrankcase.Distorted(bent)crankshaft.RoughCrankshaftsurface.

    Engineworkconditions:Workunderhightorqueatlowrotationspeed(climbing)foralongperiod.Workatarotationspeedbeyondtheupperlimit.Nonauthorizedimprovementsoftheengineforpowerincrease.

    ThemajortypeofenginebearingfailureisFatigue.Fatigueofenginebearingmaterialsiscausedbyrunningthebearingataloadabovethefatiguelimit.

    Thecausesofenginebearingfatigue:

    WrongselectionoftheEnginebearingmaterialsfortheapplication.Localizedloadingofthebearingduetoamisalignment(eg.hourglassjournal,distortedconnectingrod).Fueldetonationcausedbyadvancedignition.Runningtheengineunderhighloads(torque)atlowrotationspeedsforlongperiod.Poorconformingofthebearingbackwiththehousingsurface.Overfueling.Corrosiveactionofcontaminatedoil,whichlowersthefatiguelimit(Corrosionfatigue).

    Typesofenginebearingfailure:

    FatigueofoverlayFatigueofcopperbasedliningFatigueofaluminumbasedliningMetaltometalcontactBentortwistedconnectingrodImperfectjournalgeometryCavitationerosion

    Fatigueofoverlay

  • 7/26/2015 Enginebearingfailure[SubsTech]

    http://www.substech.com/dokuwiki/doku.php?id=engine_bearing_failure 3/10

    Fatigueofanoverlayappearsinformofanetworkofthincracks.

    Thinneroverlaysformthinnerfatiguecracks.

    Fatiguelimitofanoverlayisdeterminedbythestrengthofthematerialandthethicknessoftheoverlay.Thethinnertheoverlaythehigheritsfatiguestrength.

    Overlayfatigueitselfdoesnotcausetheenginefailure.

    Howeverrunningthebearingwithfatiguedoverlayforalongtimemaycausepartialflakingoftheoverlayandloweringtheoilfilmthickness.

    Theconditionsforboundarylubricationoccurredatlowoilfilmthicknessleadtoexcessivewearandlocalizedloading,whichmayresultinthefailureofthelining(intermediatelayer).

    totop

    Fatigueofcopperbasedlining

  • 7/26/2015 Enginebearingfailure[SubsTech]

    http://www.substech.com/dokuwiki/doku.php?id=engine_bearing_failure 4/10

    Fatigueofacopperbasedliningstartsfromfatigueoftheoverlay.

    Theoverlayflakesoutfromthecopperliningresultinginbreakingtheoilfilmandchangingthelubricationregimefromhydrodynamictoboundary.

    Theloadlocalizesatthecontactareacausingformationofsmallcracksontheliningsurface.

    Thecracksthenspreadthroughouttheliningthickness,meetthesteelbacksurfaceandcontinuetoadvancealongthesteelcopperboundary.

    Asaresultpartsoftheintermediatelayerdetachfromthesteelsurface.

    Fatigueofcopperliningcausesimmediateenginefailure.

    totop

    Fatigueofaluminumbasedlining

  • 7/26/2015 Enginebearingfailure[SubsTech]

    http://www.substech.com/dokuwiki/doku.php?id=engine_bearing_failure 5/10

    Appearanceoffatigueofaluminumbasedliningissimilartothatofcopperbaselining.

    Itisalsoresultofoverloadingcausedbyrunningtheengineunderhighloads(torque)atlowrotationspeedsforlongperiod,localizedloadingofthebearingduetoamisalignment,fueldetonationorotherfactors.

    Thefatiguecracksformonthesurfaceandspreadinsidetheliningreachingthesteelback.

    Thecracksthenprogressalongthebondlinebetweentheliningandthesteel.

    Piecesoftheliningflakeoutfromthesteelbackresultingintheenginefailure.

    Fatigueofaluminumalloysmayalsocauseextrusionoftheliningmaterialoutofthebearingedges.

    totop

    Metaltometalcontact

  • 7/26/2015 Enginebearingfailure[SubsTech]

    http://www.substech.com/dokuwiki/doku.php?id=engine_bearing_failure 6/10

    Metaltometalcontact(boundarylubrication)maybearesultofdifferentfactors:

    Insufficientoilconditions(oilstarvation).BreakingtheoilfilmcausedbythebearingmaterialFatigue.Misalignment(eg.hourglassjournal,distortedconnectingrod).Poorjournalsurfacefinish.Foreignparticlesembeddedintothebearingsurface.

    Metaltometalcontactmayappearinthefollowingforms:

    Acceleratedwear:thebearingisnotoverheated(shiningappearance).Wiping:thebearingisheavilyworn(overlayispartiallydisappeared),therearesignsofoverheating(blackening),partialmeltingoftheoverlay.Anexampleofawipedbearingispresentedontheleftpartofthepicture.HotShort:severewear,tornsurface,heavyoverheating,meltedoverlayandliningmaterial.AnexampleofaHotShortbearingispresentedontherightpartofthepicture.

    totop

    Bentortwistedconnectingrod

  • 7/26/2015 Enginebearingfailure[SubsTech]

    http://www.substech.com/dokuwiki/doku.php?id=engine_bearing_failure 7/10

    Distorted(bentortwistedconnectingrod)isoneofthecausesoflocalizedloadingofenginebearings.

    Overloadingofaninternalcombustionengineduetodetonationorrunningunderhightorqueatlowrotationspeedmaycausedistortionoftheconnectingrods.

    Thedistortionresultsinnonparallelorientationofthebearingandjournalsurfaces.

    Themisalignmentcauseslocalizedexcessivewearofthebearingsurfaceduetometaltometalcontact(boundarylubrication)occurringnearthebearingedge.

    LocalizedmetaltometalcontactmayalsocauseFatiguecrackingoftheEnginebearingmaterialsinthelocationsofthecontact.

    totop

    Imperfectjournalgeometry

  • 7/26/2015 Enginebearingfailure[SubsTech]

    http://www.substech.com/dokuwiki/doku.php?id=engine_bearing_failure 8/10

    Imperfectjournalgeometryisalsoacauseoflocalizedloadingofenginebearings.

    Useofawornstoneingrindingacrankshaftresultsinobtaininganimperfect(outofshape)journalsurface:tapershape,hourglassshapeorbarrelshape.

    Thepartsofthejournalsurfacehavinghigherdiameter(centralpartofthebarrelshapejournal,edgepartsofhourglassshapejournal)cometometaltometalcontact(boundarylubrication)withthebearingsurface.

    Themetaltometalcontactcausesexcessivewear.

    FatiguecrackingoftheEnginebearingmaterialsmayoccurinthecontactareas.

    totop

    Cavitationerosion

  • 7/26/2015 Enginebearingfailure[SubsTech]

    http://www.substech.com/dokuwiki/doku.php?id=engine_bearing_failure 9/10

    Cavitationoccurswhentheloadappliedtothebearingfluctuatesathighfrequency(highRPM).

    Theoilpressureinstantlyfallscausingformationofcavitiesduetofastevaporation(boiling).

    Whenthepressurerisesthevaporcavities(cavitationbubbles)contractathighvelocity.Suchcollapseresultsinimpactpressure,whichmayerodethebearingmaterial.

    Theoilpressurecreatesasupportingforceseparatingthejournalfromthebearingsurface.

    SoftLeadbasedenginebearingoverlaysoftrimetalbearingsarepronetothecavitationerosion.

    totop

    Relatedinternallinks

    BearingsininternalcombustionenginesEngineparametersdeterminingbearingloadingLubricationregimesHydrodynamicjournalbearingHydrodynamiclubricationtheoryGeometricalparametersofenginebearingsMechanismsofwearRequirementstoenginebearingmaterialsEnginebearingfatiguetest

  • 7/26/2015 Enginebearingfailure[SubsTech]

    http://www.substech.com/dokuwiki/doku.php?id=engine_bearing_failure 10/10

    EnginebearingmaterialsCopperbasedbearingmaterialsManufacturingbimetalstripsforcopperbearingsAluminumbasedbearingmaterialsContinuouscastingofaluminumbasedbearingalloysManufacturingbimetalstripsforaluminumbearingsLeadbasedenginebearingoverlaysTinbasedenginebearingoverlaysSputterbearingoverlaysPolymerbasedenginebearingoverlaysSelectionofenginebearingmaterialsEffectoflowviscosityoilsonenginebearingspMaxBlackStrengthenedTrimetalBearingMaterialsforHighPerformanceBearingsUGrooveModifiedDesignofOilGrooveforHighPerformanceBearingsElliptiXOilHoleofNewDesignforHighPerformanceBearingsEccentriXOptimalEccentricityforHighPerformanceBearingsRadiaLockDesignofCrushHeightforReliablePressFitofHighPerformanceBearingsModernTrendsInMaterialsForHighPerformanceEngineBearingsOptimizationofClearanceDesignforHighPerformanceEngineBearingsCamshaftBearingsEcologicalAspectsOfEngineBearingsFatigue

    Relatedexternallinks

    http://www.waukbearing.com/downloads/Material_For_Plain_Bearings.pdf[http://www.waukbearing.com/downloads/Material_For_Plain_Bearings.pdf]http://www.ilot.edu.pl/Journal%20of%20KONES%202004/01/46.pdf[http://www.ilot.edu.pl/Journal%20of%20KONES%202004/01/46.pdf]http://www.marinediesels.info/2_stroke_engine_parts/Other_info/bearing_materials.htm[http://www.marinediesels.info/2_stroke_engine_parts/Other_info/bearing_materials.htm]

    toMetalstoEnginebearings

    engine_bearing_failure.txtLastmodified:2015/03/12bydmitri_kopeliovich

    Exceptwhereotherwisenoted,thisworkislicensedunderaCreativeCommonsAttributionNoncommercialShareAlike3.0License


Bearing Failure on Coke Cart

Bearing Failure on Coke Cart

CRA E EE - jegs.com · How to Prevent Engine Failure! WHY ENGINES FAIL BEST WAYS TO PREVENT FAILURE Bearing failure due to improper pre-lubrication. Follow instructions on Page 4.

CRA E EE - jegs.com · How to Prevent Engine Failure! WHY ENGINES FAIL BEST WAYS TO PREVENT FAILURE Bearing failure due to improper pre-lubrication. Follow instructions on Page 4.

How Water Causes Bearing Failure

How Water Causes Bearing Failure

1 Bearing Capacity Theory Bearing Capacity. 2 Bearing Capacity Failure a) General Shear Failure Most common type of shear failure; occurs in strong soils.

1 Bearing Capacity Theory Bearing Capacity. 2 Bearing Capacity Failure a) General Shear Failure Most common type of shear failure; occurs in strong soils.

23291499 Bearing Failure

23291499 Bearing Failure

COATED PERFORMANCE ENGINE BEARING

COATED PERFORMANCE ENGINE BEARING

ENGINE BEARING - MAHLE Aftermarket

ENGINE BEARING - MAHLE Aftermarket

Skf Bearing Failure and Causes

Skf Bearing Failure and Causes

57115921 Bearing Failure

57115921 Bearing Failure

Case Study on Bearing Failure

Case Study on Bearing Failure

Case Study - Grinding Mill Bearing Failure

Case Study - Grinding Mill Bearing Failure

Primer Bearing Failure Detection

Primer Bearing Failure Detection

CAUSES OF ENGINE BEARING FAILURE - … · CAUSES OF ENGINE BEARING FAILURE The aim of this manual is to enable the reader to diagnose the causes of engine bearing ... frequent causes

CAUSES OF ENGINE BEARING FAILURE - … · CAUSES OF ENGINE BEARING FAILURE The aim of this manual is to enable the reader to diagnose the causes of engine bearing ... frequent causes

Engine Bearing Failure Analysis Guide · Engine Bearing Failure Analysis Guide Edge Wear Due to Distorted Connecting Rod Imperfect Journal Geometry Cavitation Erosion Spinning of

Engine Bearing Failure Analysis Guide · Engine Bearing Failure Analysis Guide Edge Wear Due to Distorted Connecting Rod Imperfect Journal Geometry Cavitation Erosion Spinning of

Failure analysis of centrifugal fan's bearing

Failure analysis of centrifugal fan's bearing

Engine Bearing Failure Analysis By Clevite · Engine Bearing Failure Analysis By Clevite 1965 From the library of Barrington Diesel Club

Engine Bearing Failure Analysis By Clevite · Engine Bearing Failure Analysis By Clevite 1965 From the library of Barrington Diesel Club

Bearing Failure Analysis Guide CL77-3-402 - · PDF fileEngine Bearing Failure & Analysis Guide Engine bearings will not function properly if they are installed wrong. In many cases,

Bearing Failure Analysis Guide CL77-3-402 - · PDF fileEngine Bearing Failure & Analysis Guide Engine bearings will not function properly if they are installed wrong. In many cases,

Root Cause Failure Analysis - Bearing

Root Cause Failure Analysis - Bearing

AIRCRAFT ENGINE OVERHAUL - Victor · PDF fileAIRCRAFT ENGINE OVERHAUL ... cause premature bearing failure, cause accelerated fatigue to sensitive aircraft electronics, propeller, and

AIRCRAFT ENGINE OVERHAUL - Victor · PDF fileAIRCRAFT ENGINE OVERHAUL ... cause premature bearing failure, cause accelerated fatigue to sensitive aircraft electronics, propeller, and

Bearing Failure Analysis Guide CL77-3-402 - Dark Side · Engine Bearing Failure & Analysis Guide 1. Check all connecting rod housing bores for taper, roundness and size, using a bore

Bearing Failure Analysis Guide CL77-3-402 - Dark Side · Engine Bearing Failure & Analysis Guide 1. Check all connecting rod housing bores for taper, roundness and size, using a bore