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TechnicalinformationENGLISH•METRICαββα23AcloserlookNORD-LOCK’sprovenwedge-lockingmethodmeetingDIN25201utilisestensioninsteadoffrictiontosecureaboltedjoint,makingitsuperiortotraditionalmethods.TheNORD-LOCKboltsecuringsystemincorporatesapairofwashersthathavecamfacesononesidewiththecamangle“a“greaterthanthethreadpitch”b”.Inaddition,thereareradialteethontheoppositesides.Thepre-assembledwashersareinstalledinpairs,camfacetocamface.Whentheboltand/ornutistightenedtheteethoftheNORD-LOCKwashersgripandlockthematingsurfaces,allowingmovementonlyacrossthecamfaces.Anyrotationofthebolt/nutisblockedbythewedgeeffectofthecams.23ThetalentbehindthecurvesWorkingtogetherwithuscanoptimiseyourapplications.Putyourboltedjointstothetestsimulatingaworst-casescenario.Atourin-houselaboratorywerunvibrationtestsandmeasuretorque-loadratios.TheJunkervibrationtestmeetingDIN65151isanexcellentmethodfortestingandcomparingthesecurityofboltedjoints.InaJunkertesttheboltedjointissubjectedtotransversemovementswhilethetensionisbeingcontinuouslymeasuredbyaloadcell.ThediagramdisplaysNORD-LOCK´ssuperiorperformance.Mostofthecommonlyusedlockingdevicesshowlimitedholdingperformancewhenexposedtovibration.Whereas,boltedjointssecuredwithNORD-LOCKwashersonlylosesomeoftheinitialpreloadduetonormalsettlementsbetweenthecontactsurfaces.NORD-LOCK’suniquewedge-lockingfunctionisprovedbytheclearincreaseinclamploadduringuntightening.Theuniquewedge-lockingactionoftheNORD-LOCKwasherscaneasilybeverified.TightenaboltedjointwithNORD-LOCK,thenuntighten.Duringuntightening,slidingmustalwaysoccurbetweenthecamfacesofthewashers.Uponoverridingofthecamsa“clickeffect”shouldbefeltwhenthenut/boltcomesloose.Visualinspectionofthematingsurfacesshouldshowclearimpressionmarksmadebytheradialteethofthewashers.Whenthesecriteriaaremet,NORD-LOCKwasherswillsafelylockboltedjointsexposedtoseverevibrationanddynamicloads.LoadcyclesRegularnutM8onboltwithNORD-LOCKat70%ofyieldpointRegularnutM8onbolt,clamplength50mmNylon-insertednutSplitringRegularnutM8onboltClampload[kN]UntighteningVibrationtestboltM8(8.8)withclamplength25mm45HighqualitymaterialNORD-LOCKwashersareavailableinavarietyofmaterials,whichallcomplywithEuropeandirectivesonELV&RoHS.WashertypeRangeZincflakecoated(flZnnc-600)Non-coatedSteel(throughhardenend)NL3–NL130465HV1Stainlesssteel(surfacehardened)NL3ss–NL80ss520HV0.05HardnesstablePleasenote:InordertoassuretheuniquemechanicallockingfunctionoftheNORD-LOCKwashers,thehardnessofthematingsurfacesmustbelowerthanthehardnessoftheNORD-LOCKwashers(seetableabove).OurstandardsteelwashersarecoatedwiththezincflakecoatingDeltaProtekt®.Theprocessincludesabaseandtopcoat.ZincflakecoatedNORD-LOCKwashersendureaminimumof600hoursofsaltspraytestinginaccordancewithISO9227.TheimagetotherightshowsasampleofzincflakecoatedNL24washersafter1000hoursofsaltspraytesting.NORD-LOCKsteelwashersaremadeofEN1.7182orequivalentalloy.Allsteelwashersarethroughhardened.NORD-LOCKstainlesssteelwashersaremadeofEN1.4404(USstandardAISI316L)orequivalentalloy.Allstainlesssteelwashersaresurfacehardened.Othersteelalloysavailableonrequest254SMO-forhighlycorrosiveenvironment-madeofEN1.4547orequivalentalloyINCONEL®718-forhightemperatureenvironment-madeofEN2.4667orequivalentalloyINCONEL®/HASTELLOY®C-276-foracidenvironment-madeofEN2.4819orequivalentalloy45FlangednutwithNLsp(enlargedouterdiameter)PaintedsurfaceafteruseofNORD-LOCKwithstandarddiameterPaintedsurfaceafteruseofNORD-LOCKwithenlargedouterdiameterClampload[kN]LoadcyclesVibrationtestslottedholesFlangednutwithNORD-LOCKsp(enlargedouterdiameter)RegularnutwithNORD-LOCKsp(enlargedouterdiameter)RegularnutwithNORD-LOCKstandard(standardouterdiameter)PaintedsurfacesNORD-LOCKwasherssafelysecureboltedjointsonpaintedsurfacesprovidedthewashers’teethproperlyimpressintothepaintedmatingsurface.Uponuntighten-ingslidingwilloccurbetweenthecamfacesofthewashersassuringtheuniquewedge-lockingeffectwhileavoidinganyabradingofthepaintedsurface.RegularnutwithNL(standardouterdiameter)RegularnutwithNLsp(enlargedouterdiameter)Counter-bores&slotsNORD-LOCK’souterdiametersaresuitableforcounter-bores.Inaddition,washerswithenlargedouterdiameter(sp)areavailableforuseonlarge/slottedholes,paintedsurfacesorsoftmaterials,e.g.aluminium.ForoptimumresultsuseNORD-LOCKspwasherstogetherwithflangednuts/bolts.ExampleforJunkervibrationofM12bolt(8.8)67MinimizetorsionalstressDuringtightening,boltsaresubjectedtobothtensileandtorsionalstress.Thedesiredtensilestress(clampload)isachievedwhentheboltisaxiallyelongated.Unwantedtorsionalstress(twisting)inboltsarisesduringtighteningduetofrictionbetweenthecontactsurfacesinthethreads.Highthreadfrictionincreasestwistingoftheboltsandcausesyieldingatlowerclamploadlevelsthannormal.Applyinganadhesivesignificantlyincreasesthreadfrictionduringtightening.Thegraphtotherightshowsthatwhentighteningboltswithadhesivesonthethreads,onlyhalfasmuchclamploadwasobtainedbeforereachingtheyieldpointscomparedtowhentighteningsimilarboltslubricated.SinceNORD-LOCK’suniquewedge-lockingtechniqueisnotaffectedbylubrication,thethrea
本文标题:NORD-LOCK锁紧垫圈
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