Rotary Seals - All Seals Inc.

1 Your Partnerfor SealingTechnologyRotarySealsnV-RINGnGene ralFigure53 Methodof operationof theV RingTheV-RINGis the1960 sbyFORSHEDAAB,it hasbeenusedsuccessfullyby OEMsandon thereplacementmarketworldwidein abroadrangeof Ringis theperfectsealto preventtheingressof dirt,dust, uniquedesignandperformancetheV Ringcanbe canalsobe usedas asecondarysealtoprotectprimarysealsthatd o notperformwellin Ringis normallystretchedandmounteddirectlyonthe shaft,whereit is heldin positionby theinherenttensionof ,perpendicularto thesidewallof abearingor awasher,stamping,bearinghousing,or eventhemetalcaseof an oil is flexibleandappliesonlyarelativelylightco ntactpressureagainstthecounter-faceandye tis stillsufficientto (thatvarieswiththefittedwidth)

2 Allowsthesealto rundryin influenceof thecentrifugalforce,thecontactpressureof thelip frictionallossesandheatarekeptto aminimum,resultingin overcome,thefrictionreducesteadilyuntila roundthe10 -15m/srange,whenit 15 -20m/srangethefrictionreducesto Ringthenservesas powerlossdueto sealfrictiondevelopsas shownin andhingeallowtheV Ringto functionevenin thepresenceof acertainamountof run-out, Ringsare madeentirelyof rubberwithoutfabricor ,therefore,particularlyeasyto Ringscanbe stretchedand,dependingon size,installedoverflanges, suppliedas cut ringsandjoinedby vulcanisationon Ringsareavailablein profilesAand Sincreasewiththeshaftdiameter,whilsttheo thertypeshavethesamecross-sectionfor to 2020mm, , to LX havenarrowaxialcrosssectionsmakingthemsu itableforcompactarrangementsandareoftenu sedin (135for LX)to ,RMandAXareheavydutyV Ringsthataredesignedprimarilyforlargehig hspeedbearingarrangements,I.

3 E. usedas secondarysealsforheavydutyapplicationswh eretheprimarysealhasto beprotectedagainstwaterandor ,RMandAXtypescanbe axiallyandradially locatedontheshaft with theespeciallydesignedclampingbands(seepa ge148). Ringsizesareavailableas RingLatestinformationavailableat (m/s)7065605550454035302520151050d = shaft diameter(mm)TechnicalData:- Dry running- Matingsurfacesteel,unhardenedV-Rings in low frictionnitrile(N6T5C)V-Rings for generaluse (N6T50) this graphis basedon a specifictest, the valuesshouldonly beregardedas indicative!Powerloss (W)Figure54 Powerlossas afunctionof peripheralspeedfor varioussizesnMaterialsWhenselectingtheco rrectrubbercompoundit is necessaryto takethefollowingrequirementsintoaccount; -goodchemicalresistance-goodresistanceto highandlowtemperatures-goodresistanceto ozoneandweatheringIt is alsonecessaryto considertheneedfor thefollowingattributes.

4 -highresistanceto wear-lowfriction-lowcompressionset-goode lasticityMaterialtypesThemostfrequentlys electedmaterialis C, or inchemicallyaggressiveconditions,V Ringsmadeoffluorinatedrubber(FKM)canbe factawiderangeof rubbercompoundsis availableandsomeof XXXIXG uideto selectionof rubbermaterialTSScodeOld(FORSHEDA)codeTy pe 415 ChloropreneForapplicationsin thepresenceof ozoneE7T50 EPDM762 Ethylene-PropyleneGoodweatherandozoneres istance,usedwithspecialchemicalssuchas acetone,ammoniumcarbonateandbenzaldehyde VDT50 FKM900 FluorinatedVery hightemperatureandchemicalresistanceV RingLatestinformationavailableat highertemperaturesacceleratetheageingofr ubber,theelongationdecreases,thecompress ionsetincreases, andfinallythematerialbecomes hard thesealingedgeareatypicalindicationthatt hesealhasbeenexposedto theusefullifeof regardedasapproximate,sincethemediaandti meof allowedfor onlycertainperiodsof.

5 Themaximumtemperatureis exceeded,theelastomermaysufferpermanents etor availablefor usein theelastomeris subjectedto temperatureslowerthantherecommendedvalue sit willbecomehardandbrittle,howeverit will regainits properties as soonas -3590160-35-25110180-100-60130220-40 -30150250-100-500+50+100+150+200+250 Temperature COnly to be achievedunderparticularconditionswith V RingsOil andsolventresistanceSincetheV Ringis usedprimarily forsealinggreaselubricatedbearingsexpose dto watersplash,dirt,dust, compoundis NitrileRubber(N6T50) oilareavailableon themarketandeachof ,agiventypeof oil is theadditivesin theoil forhypoidoils, usedas thevulcanisingagentfor nitrilerubberitwillinitiateasecondarycur ingat temperaturesabove+80 C.

6 As aresultof that, ,whicharenotvulcanisedwithsulphur,may thereforebeconsideredforusewiththistypeo f resistanceof swellingof therubberhowevermixturesof oil andsolventresistancewerecommendyouto bein normallyfullyexposedto themediumto theshaftandthecounterfacearemainlydepend enton Ringis in mostcasesfittedon theV Ringisan all-rubbersealit canbe stretchedto avaryingdegreeandbe usedfor awiderangeof applicationswherelowpowerlossandlonglife timeareimportant it is recommendedthattheV Ringsizeisselected,so becausethecontactpressureof thesealinglipincreaseswiththeshaftdiamet er,due to thestretchof theV ahigherstretch,ahardercontactpressureisg enerated,causingan acceleratedwearof orderto preventtheV Ringfromslidingalongtheshaft,andto ensurethecorrectinstallationwidth,it is alwaysrecommendedto arrangean axialsupport,especiallyforsmallcross-sec tionprofilesandlargershaft sizes,forexampleV RingtypeA, Land RingLatestinformationavailableat theshaftshouldin generalnotexceedRa m.

7 Forsealingfluidsandfineparticles,amaximu mof Ra ,whichcandamagetheV Ringmustbe be sealedandtheperipheralspeedof theshaftdeterminetherequirementsregardin gsurfaceroughnessandmaterialof is importantthatit is achievethefulleffectof theflingeraction,theV Ringshouldalwaysbe designedin to keepthegapbetweentheshaftandthecounter-f aceas smallas possible,in ordertoprevententryof theV Ringlip ,stainlesssteelor zincplatedsheetareexcellentmaterialsfor ,thechoiceof materialis highlydependenton themediumtobe ,conventionalmildsteelwithahardnessof ,oil anddryparticlesnofurthersurfacetreatment is increasein speedandthepresenceof abrasiveparticlesthehardnessof thecounter-facemustalsobe.

8 MaterialHardnessHBMediumMildSteel125-150 Water splash,sand,dustGreyCastIron190-270 Water splash,sand,dustSinterBronze100-160 Water,dustStainlessSteel(Cr/Ni18-8, )150-200 WaterStainlessSteel(Cr/Ni18-8, )Work-hardened350 Water andabrasiveparticlesAcidProofSteel180-20 0 ChemicalsTungstenCarbide350-500 Water andscaleForgedSteel200-255 Water andscaleDie-castAluminium90-160 Water splashSurfacetreatmentWhenthecounter-fac e is exposedtowaterorothercorrosivemedia,it mustbe ,chromiumplated,treatedwithananticorrosi onspray, treatmentwilldependon immersedin water, ,duetothepoorthermalconductivitystainles ssteelshouldnotbeusedin dryrunningconditionsunlessthespeedis slow(<1m/s).

9 SurfacefinishTherateof abrasionof theV Ringis influencedby anumberof factors,oneof whichis thesurfacefinishof surfacefinishwilldependonthemediumto be sealedandtheshaftspeedas isnotonlythesurfacefinishvalueas suchthatis important, turnedsurfaces,it isrecommendedto buffthe , ,maycauseasuctioneffectbetweentheV Ringlipandthecounter-faceresultingin noiseproblemsandunevenrunning(so-calleds tick-slipeffect).Thecounterfacesurfacemu stbe recommendedsurfacefinishSurfacefinish >10 Oil,water,scale, splash,grease, ,dust,watersplash, <1 Grease,dustThesurfacefinishshouldnotbe lowerthanRa thecounter-faceis of importance,especiallyat normallydefinedas RingLatestinformationavailableat retainoil andgrease,an axialsupportfortheV Ringis stretchthanrecommendedin thedimensiontables( assembly)or withashaftspeedexceeding6-8m/s(depending on therubbercompoundselected)an axialsupportis thecounter-faceis Ringmustalwaysbe supportedoverits designedin accordancewithFigure56.

10 ThedimensionsA, c, d1, theaxialsupportdiameterd5is as follows;V RingtypeDiameter d5A, Sd1+ xcL, LXd1+3mmRM,RMEd1+10mmAXd1+ AAd1cFigure56 AxialsupportRadialretentionWhentheV Ringis fittedon theshaft,thebodyof theV Ringis subjectto acentrifugalforceandtendsto moveor evenlift offfromtheshaftat shaftspeedsover10-12m/s,dependingon theV Ringmaterial,theV Ringin requiredis alsodependentonthedegreeof stretchof theV Ringslargerthan2000mmshouldalwaysbefitte dwithradialretention,irrespectiveof designedas arecess,in whichtheV Ringbodyfits,or consistof anumberof caseswheretheperipheralspeedof theshaftexceeds10-12m/san alternativemethodto radialclampingis tomounttheV Ringon astationarycomponentin thelip willremainconstant,astherewillbe no comparisonto arotatingV Ring,frictionandpowerlosswillbe higherresultingin compensatefor thisthefollowingstepsshouldbetaken:Count er-facesurfacefinish:machineto mRaV Ringstretch:maximum4-6%Axialinterference .