發(fā)動機故障詢問與分析

故障分析檢查

FailureAnalysisReview發(fā)動機為何發(fā)生故障?該故障是否在保修范圍內(nèi)?Whydidthisenginefailandisitawarrantablefailure?故障分析過程

TheProcessofFailureAnalysis詢問顧客Questionthecustomer

核實投訴/癥狀

Verifycomplaints/symptoms

拆卸Disassemble

定義故障類型Definethetypeoffailure

確定原因Determinethecause

排除故障原因，防止再次發(fā)生。Correctthecauseoffailuretopreventfurtheroccurrence.詢問顧客

QuestiontheCustomer詢問維護記錄

Askaboutmaintenancehistory

問題發(fā)生持續(xù)時間Lengthofproblemoccurrence

故障發(fā)生前的癥狀(如噪音、煙霧等)Symptomspriortofailure(i.e.,noise,smoke,etc..)

故障發(fā)生前是否有任何異常Anyabnormalitiespriortofailure

操作機器的人是否為機器所有者Wasowneroperatingmachine核實投訴和檢查癥狀

VerifyComplaint&CheckSymptoms運行狀態(tài)是否與描述的一樣?Isitworkingasdescribed?檢查以下各項LOOKFORTHEFOLLOWING

漏油OilLeaks

煙霧Smoke

檢查液位Checkfluidlevels

機器的整體狀況Overallconditionofunit

是否有任何改造Anymodifications拆卸

Disassembly拆卸零件/發(fā)動機Disassemblethecomponent/engine放置好零件，使其免受損壞并便于以后檢查Organizepartstoprotectfromdamageandforlaterreview如有需要，對油、燃料和冷卻液進行采樣Takeoil,fuel,andcoolantsamplesincasetheyareneeded尋找解決疑難問題的線索Lookforcluestosolvethemystery故障類型

TypesofFailure活塞環(huán)損壞和故障PistonRingDamage&Failure活塞損壞和故障PistonDamage&Failure軸承故障BearingFailures曲軸故障CrankshaftFailures其它零件故障Othercomponents活塞環(huán)故障分析

PistonRingFailureAnalysis微粒磨損FineAbrasiveWear環(huán)劃痕RingScoring粘性環(huán)StickingRings斷裂Breakage微粒磨損

FineAbrasiveWear外觀/線索：Appearance/Clues:外表呈暗灰色DullGrayFinish細小垂直劃痕FineVerticalScratches積碳CarbonBuild-up環(huán)形槽磨損WornRingGrooves油環(huán)軌磨損WornOilRingRails微粒磨損

FineAbrasiveWear可能的原因：PossibleCauses:空氣濾清器泄漏LeaksinAirCleaner空氣過濾器維護不當ImproperAirFilterMaintenance維修后發(fā)動機中留有磨屑AbrasivesLeftinEngineafterRepair加油時漏斗中有臟物DirtinFunnelswhenAddingOil環(huán)劃痕

RingScoring外觀/線索Appearance/Clues金屬錯位造成的明顯凹槽VisibleGroovesCausedbyDisplacedMetal可能是鋼制零件變色PossibleDiscolorationofSteelParts刮傷的環(huán)

ScoredRings可能的原因：PossibleCauses:缺少潤滑LackofLubrication過度供油Overfueling冷卻液泄漏到氣缸內(nèi)CoolantLeakingintoCylinder過熱和過載Overheating&Overloading活塞上有積碳CarbonBuilduponpiston粘性環(huán)

StickingRings外觀/線索Appearance/Clues環(huán)上沉積物過多ExcessiveRingDeposits環(huán)過度磨損ExcessiveRingWear環(huán)被卡在槽內(nèi)RingsSeizedinGrooves環(huán)和活塞在后階段磨擦ScuffingofRingsandPistonsinLaterStages粘性環(huán)

StickingRings可能的原因：PossibleCauses:沉積物過多ExcessiveDeposits燃燒不充分PoorCombustion過早磨損PrematureWear發(fā)動機油使用時間過久ExtendedEngineOilService環(huán)斷裂

RingBreakage外觀/線索Appearance/Clues斷裂！Broken!磨損或刮傷ScuffingorScoring槽變寬或變形WidenedorDeformedGroove氣缸壁有劃痕CylinderWallScratching新斷裂處FreshBreak!斷裂的環(huán)

BrokenRings可能的原因：PossibleCauses:組裝不當ImproperAssembly沖擊載荷ShockLoading環(huán)槽過寬ExcessiveRingGrooveWidth積碳過多ExcessiveCarbonBuild-up使用了啟動劑UseofaStartingAgent除塵不當SevereDusting是的，如果對發(fā)動機除塵，拆下了活塞而沒有拆下環(huán)脊，可能會弄斷環(huán)，這可能就是導致故障的原因。Yes,ifanengineisdustedandyouremovethepistonswithoutremovingtheridge,youmaybreaktheringsandthinkthattheyarethecauseoffailure.活塞故障分析

PistonFailureAnalysis微粒磨損FineAbrasiveWear爆裂Detonation活塞磨損PistonScuffing活塞刮傷PistonScoring活塞卡住PistonSeizure過熱Overheating腐蝕Erosion斷裂Breakage微粒磨損

FineAbrasiveWear外觀/線索Appearance/Clues外表呈暗灰色DullGrayFinish細小垂直劃痕FineVerticalScratches環(huán)槽磨損WornRingGrooves油環(huán)軌磨損WornOilRingRails積碳CarbonBuild-up微粒磨損

FineAbrasiveWear可能的原因：PossibleCauses:空氣濾清器維修過度Over-servicingAirCleaner空氣過濾器系統(tǒng)泄漏LeaksinAirFilterSystem來自臟漏斗中的臟物DirtfromDirtyFunnels大修后發(fā)動機中留有磨屑AbrasivesLeftinEngineafterOverhaul爆裂

Detonation外觀/線索Appearance/Clues活塞斷裂FracturedPiston穿孔Holes零件斷裂PartsBroken爆裂

Detonation可能的原因：PossibleCauses:啟動劑StartingAgents正時不正確IncorrectTiming發(fā)動機振動Lugging冷卻不足InadequateCooling燃料中有汽油GasolineinFuel活塞磨損

PistonScuffing外觀/線索Appearance/Clues垂直劃痕VerticalScratches外表呈暗灰色DullGrayFinish環(huán)槽磨損WornRingGrooves活塞磨損

PistonScuffing可能的原因：PossibleCauses:間歇性潤滑不足IntermittentLackofLubrication預熱時間過短ImproperWarm-up過度供油Overfueling過熱/100%防凍劑Overheating/100%Antifreeze過載Overloading重新裝配時，磨屑清洗不當ImproperCleaningofAbrasivesduringRebuild活塞刮傷

PistonScoring外觀/線索Appearance/Clues金屬錯位造成的明顯凹槽VisibleGroovesCausedby

DisplacedMetal可能是鋼制零件變色PossibleDiscolorationofSteelParts活塞刮傷

PistonScoring可能的原因：PossibleCauses:過熱Overheating缺少潤滑LackofLubrication過度供油Overfueling環(huán)棱中或活塞上有積碳CarbonBuild-upinRingLandoronPiston活塞卡住

PistonSeizure外觀/線索Appearance/Clues嚴重刮傷和金屬變形SevereScoring&MetalTransfer可能是銷徑處的活塞斷裂PossiblePistonBreakageatPinBore活塞或環(huán)棱熔化，熱變色MeltedPistonorRingLands,HeatDiscoloration裂縫Cracking活塞卡住

PistonSeizure可能的原因：PossibleCauses:大修中使用了錯誤的活塞WrongPistonusedDuringOverhaul缺少潤滑LackofLubrication活塞銷/徑斷裂PistonPin/BoreBreakage氣缸中有冷卻液CoolantinCylinder以下是活塞卡住的示例，活塞上留下的痕跡是閥撞擊造成的損傷。ExampleofPistonSeizurewithdamagefromvalvehittingwhatwasleftofpiston腐蝕

Erosion外觀/線索Appearance/Clues表面磨損或腐蝕WornawayorErodedSurface表面生銹、有蝕坑Rusted,PittedSurface表面有氣蝕的凹坑CavitationPittedSurface腐蝕

Erosion可能的原因：PossibleCauses:燃料噴油嘴泄漏LeakingFuelInjector正時提前AdvancedTiming在高處運轉而功率不降低HighAltitudeOperationwithoutDerating活塞環(huán)斷裂BrokenPistonRings斷裂

Breakage外觀/線索Appearance/Clues活塞破碎PistoninPieces刮傷Scoring閥標記ValveMarkings熱變色HeatDiscoloration斷裂

Breakage可能的原因：PossibleCauses:卡住Seizure使用了乙醚EtherUsage預燃室松動LoosePre-CombustionChambers過度供油Overfueling進氣口中有碎片DebrisinAirIntake軸承故障分析

BearingFailureAnalysis軸承變色BearingDiscoloration軸承缺油OilStarvation過載Overloading放電故障ElectricDischargeFailure磨蝕Fretting氣蝕CavitationErosion軸承變色

BearingDiscoloration外觀/線索Appearance/Clues軸承邊緣呈現(xiàn)乳灰色MilkyGrayonEdgeofBearing軸承邊緣有黑色腐蝕BlackCorrosiononEdgeofBearing非常暗的灰色，比較光滑的表面VeryDullGray,RelativelySmoothSurface青藍色/黑色Bluish/Black有黑色的“痕跡”，像拖痕和穿過軸承電弧焊機的電極Black“Tracks”,LikeDraggingandArcWelderElectrodeAcrossBearing軸承中的油槽黑化OilGroovesinBearingareBlackened軸承變色

BearingDiscoloration可能的原因：PossibleCauses:水/防凍劑污染W(wǎng)ater/AntifreezeContamination潤滑不足InsufficientLubrication微粒磨光FineParticlePolishing油溫高HighOilTemperature燃料污染FuelContamination放電ElectricDischarge軸承缺油

OilStarvation外觀/線索Appearance/Clues磨損的表面發(fā)亮ShinyWearSurface污點Smearing,then磨損Scuffing,then刮傷Scoring,then卡住Seizure,then孔徑內(nèi)旋轉SpinninginBore在“高負載”區(qū)域顯示過早磨損ShowsPrematureWearin“HighLoad”Areas軸承缺油

OilStarvation可能的原因：PossibleCauses:油被稀釋DilutionofOil油位低LowOilLevel濾油器或濾網(wǎng)堵塞RestrictedOilFilterorScreen油泵磨損WornOilPump油盤堵塞RestrictedOilGalleys吸附碳或污垢CarbonorDirtIngestion潤滑不足

InsufficientLubrication這是潤滑不足的個案研究示例。ThisisaCaseStudyexampleofinsufficientlubrication.連桿主線過載

Overloading外觀/線索Appearance/Clues“高負載”區(qū)域的磨損Wearon“HighLoad”Areas軸承被錘打變薄BearingHammeredThin發(fā)出錘打噪音(敲擊)HammeringNoises(Knock)過載

Overloading可能的原因：PossibleCauses:發(fā)動機振動LuggingtheEngine在齒輪速度過高的狀態(tài)下運行機器OperatingUnitinTooHighofGear試圖運行更大的機器AttemptingtodoWorkofaLargerUnit放電故障

ElectricDischargeFailure外觀/線索Appearance/Clues曲軸的表面結霜FrostedAppearanceofCrankshaft主軸承“高負載”區(qū)域中的過早磨損PrematureWearinMainBearing“HighLoad”Area連桿軸承未損壞RodBearingsAreUndamaged主軸承背面有黑色點蝕MainBearingBacksHaveBlackPitting曲軸的負載端損壞DamagetoLoadedEndofCrankshaft放電

ElectricDischarge可能的原因：PossibleCauses:機器上的電弧焊接ArcWeldingonUnit系統(tǒng)接地不良PoorSystemGround電流被其它電源放電ElectricCurrentbeingDischargedbyOtherSources電動離合器安裝與接地不當ElectricClutchesImproperlyInstalledandGrounded磨蝕

Fretting外觀/線索Appearance/Clues早期的輕度粘著磨損LightAdhesiveWearinEarlyStages軸承表面點蝕PittingOnBearingSurfaces生銹和腐蝕RustandCorrosion軸承背面和孔變色DiscolorationonBearingBackandBore磨蝕

Fretting可能的原因：PossibleCauses:孔徑內(nèi)軸承松動BearingLooseinBore固定蓋螺栓的扭矩不正確IncorrectRetainingCapBoltTorque錐孔不圓BoretaperOutofRound軸承擠壓力不足PoorBearingCrush請記住，極少量的磨蝕被視為正?，F(xiàn)象。Remember,averysmallamountoffrettingisconsiderednormal.氣蝕

CavitationErosion外觀/線索Appearance/Clues軸承頂層的小塊碎片殘缺SmallPatchesofBearingTopLayerMissing碎片可能正好在軸承“高負載”區(qū)域前PatchesWouldbeJustBeforethe“HighLoad”AreaofBearing氣蝕

CavitationErosion可能的原因：PossibleCauses:油質(zhì)不好或等級錯誤PoorQualityOilorWrongGrade油位過低或過高OilLevelTooLoworTooHigh吸油側漏氣OilSuctionSideAirLeaks負載和速度條件過高TooHighLoadandSpeedConditions油的攪拌(空氣含量高)ChurningofOil(HighAirContent)在發(fā)動機上的時間長HighHoursonEngine曲軸故障分析

CrankshaftFailureAnalysis彎曲故障BendingFailures扭轉疲勞TorsionalFatigue彎曲故障

BendingFailure外觀/線索Appearance/Clues與曲軸中心線呈90度斷裂Breakage90degreestoCenterlineofCrankshaft斷裂表面相當光滑，有明顯的“浪狀條紋”FairlySmoothBreakwithVisible“BeachMarks”從軸頸一側到另一側斷裂FracturefromOneSideofJournaltotheOther彎曲故障

BendingFailures可能的原因：PossibleCauses:側面負載過大ExcessiveSideLoads飛輪失去平衡FlywheelOutofBalance孔未對齊MisalignedBores軸承磨損BearingWear重復過載RepeatedOverloading扭轉疲勞

TorsionalFailures外觀/線索Appearance/Clues與曲軸中心線呈45度斷裂Fracture45degreesfromCenterlineofCrankshaft軸頸周圍的斷裂螺紋FractureSpiralsAroundJournal幾道“浪狀條紋”SeveralSetsof“BeachMarks”斷裂表面呈粗糙的階梯形Rough,Step-LikeFractureSurface扭轉疲勞

TorsionalFailures可能的原因：PossibleCauses:重復過載RepeatedOver