AngleEncoderswithIntegralBearingNovember2010AngleencoderswithintegralbearingandintegratedstatorcouplingAngleencoderswithintegralbearingforseparateshaftcouplingInformationon?AbsoluteAngleEncoderswithOptimizedScanning?AngleEncoderswithoutIntegralBearing?RotaryEncoders?EncodersforServoDrives?ExposedLinearEncoders?LinearEncodersforNumericallyControlledMachineTools?InterfaceElectronics?HEIDENHAINcontrolsisavailableonrequestaswellasontheInternetatwww.heidenhain.de.Thiscatalogsupersedesallpreviouseditions,whichtherebybecomeinvalid.ThebasisfororderingfromHEIDENHAINisalwaysthecatalogeditionvalidwhenthecontractismade.Standards(ISO,EN,etc.)applyonlywhereexplicitlystatedinthecatalog.2ContentsHEIDENHAINAngleEncodersThetermangleencoderistypicallyusedtodescribeencodersthathaveanaccuracyofbetterthan±5"andalinecountabove10000.Incontrast,rotaryencodersareencodersthattypicallyhaveanaccuracybetterthan±10“.Angleencodersarefoundinapplicationsrequiringprecisionangularmeasurementtoaccuracieswithinseveralarcseconds.Examples:?Rotarytablesonmachinetools?Swivelheadsonmachinetools?C-axesoflathes?Measuringmachinesforgears?Printingunitsofprintingmachines?Spectrometers?Telescopesetc.Thetablesonthefollowingpageslistdifferenttypesofangleencoderstosuitvariousapplicationsandmeetdifferentrequirements.Angleencoderscanhaveoneofthefollowingmechanicaldesigns:Angleencoderswithintegralbearing,hollowshaftandintegratedstatorcouplingBecauseofthedesignandmountingofthestatorcoupling,itmustabsorbonlythattorquecausedbyfrictioninthebearingduringangularaccelerationoftheshaft.RCN,RONandRPNangleencodersthereforeprovideexcellentdynamicperformance.Withanintegratedstatorcoupling,thestatedsystemaccuracyalsoincludesdeviationsfromtheshaftcoupling.Otheradvantages:?Compactsizeforlimitedinstallationspace?Hollowshaftdiametersupto100mmtoprovidespaceforpowerlines,etc.?SimpleinstallationSelectionGuideForAbsoluteAngleEncodersseepages6/7ForIncrementalAngleEncodersseepages8/94TheRCN729angleencodermountedontherotarytableofamachinetoolRCN729incrementalangleencoderOverviewROD880incrementalangleencoderwithK16?atcouplingERA4000incrementalangleencoderAngleencoderswithintegralbearing,forseparateshaftcouplingRODangleencoderswithsolidshaftareparticularlysuitedtoapplicationswherehighershaftspeedsandlargermountingtolerancesarerequired.Theshaftcouplingsallowaxialtolerancesof±1mm.SelectionGuideonpages8/9AngleencoderswithoutintegralbearingTheERPandERAangleencoderswithoutintegralbearing(modularangleencoders)areintendedforintegrationinmachineelementsorapparatuses.Theyaredesignedtomeetthefollowingrequirements:?Largehollowshaftdiameters(upto10mwithascaletape)?Highshaftspeedsupto20000min–1?Noadditionalstartingtorquefromshaftseals?SegmentanglesSelectionGuideonpages10/11Youcan?ndmoredetailedinformationonHEIDENHAINmodularangleencodersontheInternetatwww.heidenhain.deorinourbrochureAngleEncoderswithoutIntegralBearing.SelectionGuideAbsoluteAngleEncoderswithIntegralBearingForpositionmeasurementForinformationaboutthenewabsoluteangleencoderswithoptimizedscanning,visitwww.heidenhain.deoraskforourcatalog:AbsoluteAngleEncoderswithOptimizedScanning.RCN200RCN700?60mmRCN800?100mmSelectionGuideIncrementalAngleEncoderswithIntegralBearing2)ForpositionmeasurementAfterintegratedinterpolationRON285RON786RON905ROD280ROD780SelectionGuideAngleEncodersandModularEncoderswithoutIntegralBearingBeforeinstallation.Additionalerrorcausedbymountinginaccuracyandinaccuracyfromthebearingofthemeasuredshaftarenotincluded.Forpositionmeasurement3)Forfurtherversions,seeappropriatecatalog4)Afterintegratedinterpolation2)Incrementalsignals/ReferenceGratingperiodmarksModelFormoreinformation?1VPP/–OneERP880Catalog:AngleEncoderswithoutIntegralBearingERP880NoneERP8080ERP4080ERP4080?1VPP/20μm?1VPP/40μm?1VPP/80μmDistance-codedERA4280CERA4480CERA4880CERA4000?1VPP/40μmDistance-codedERA780Cfullcircle(nominalincrementof1000gratingperiods)Distance-codedERA880Cfullcircle(nominalincrementof1000gratingperiods)ERA6080100mmERA6070Catalog:AngleEncoderswithoutIntegralBearingERA780?1VPP/40μm?1VPP?TTLERA6000ProductInformationERA880?1VPP/Approx.400μm?TTL/Approx.400μmERM280ERM220Catalog:MagneticModularEncodersERM28011MeasuringPrinciplesMeasuringStandardHEIDENHAINencodersincorporatemeasuringstandardsofperiodicstructuresknownasgraduations.Thesegraduationsareappliedtoaglassorsteelsubstrate.Glassscalesareusedprimarilyinencodersforspeedsupto10000min–1.Forhigherspeeds—upto20000min–1—steeldrumsareused.Thescalesubstrateforlargediametersisasteeltape.HEIDENHAINmanufacturestheprecisiongraduationsinspeciallydeveloped,photolithographicprocesses.?AURODUR:Matte-etchedlinesongold-platedsteeltapewithgratingperiodsoftypically40μm?METALLUR:Contamination-tolerantgraduationofmetallinesongold,withtypicalgraduationperiodof20μm?DIADUR:Extremelyrobustchromiumlinesonglass(typicalgraduationperiod20μm)orthree-dimensionalchromestructures(typicalgraduationperiodof8μm)onglass?SUPRADURphasegrating:opticallythreedimensional,planarstructure;particularlytoleranttocontamination;typicalgraduationperiodof8μmandless?OPTODURphasegrating:opticallythreedimensional,planarstructurewithparticularlyhighre?ectance,typicalgraduationperiodof2μmandless.Theseprocessespermitvery?negratingperiodsandarecharacterizedbyahighde?nitionandhomogeneityofthelineedges.Togetherwiththephotoelectricscanningmethod,thishighedgede?nitionisapreconditionforthehighqualityoftheoutputsignals.ThemastergraduationsaremanufacturedbyHEIDENHAINoncustom-builthigh-precisionrulingmachines.AbsoluteMeasuringMethodAbsoluteencodersfeaturemultiplecodedgraduationtracks.Thecodearrangementprovidestheabsolutepositioninformation,whichisavailableimmediatelyafterrestartingthemachine.Thetrackwiththe?nestgratingstructureisinterpolatedforthepositionvalueandatthesametimeisusedtogenerateanincrementalsignal(seeEnDatInterface).CirculargraduationsofabsoluteangleencodersIncrementalMeasuringMethodWiththeincrementalmeasuringmethod,thegraduationconsistsofaperiodicgratingstructure.Thepositioninformationisobtainedbycountingtheindividualincrements(measuringsteps)fromsomepointoforigin.Sinceanabsolutereferenceisrequiredtoascertainpositions,thescalesorscaletapesareprovidedwithanadditionaltrackthatbearsareferenceWithdistance-codedreferencemarks,theabsolutereferenceiscalculatedbycountingthesignalperiodsbetweentworeferencemarksandusingthefollowingformula:1RR22where:dMountingmark.Theabsolutepositiononthescale,establishedbythereferencemark,isgatedRRwithexactlyonemeasuringstep.Where:ThereferencemarkmustthereforebeT1=Absoluteangularpositionofthescannedtoestablishanabsolutereference?rsttraversedreferencemarktoorto?ndthelastselecteddatum.thezeropositionindegreesInsomecases,thismayrequirearotationabs=Absolutevalueuptonearly360°.Tospeedandsimplifysuch“referenceruns,”manyencoderssgn=Signfunction(“+1”or“–1”)featuredistance-codedreferencemarks—multiplereferencemarksthatareMRR=Measureddistancebetweentheindividuallyspacedaccordingtoatraversedreferencemarksinmathematicalalgorithm.Thesubsequentdegreeselectronics?ndtheabsolutereferenceaftertraversingtwosuccessivereferenceI=Nominalincrementbetweentwomarks—meaningonlyafewdegreesof?xedreferencemarks(seetable)traverse(seenominalincrementIinthetable).GP360°Encoderswithdistance-codedreferenceD=Directionofrotation(+1or–1)marksareidenti?edwitha“C”behindtheRotationtotheright(asseenfrommodeldesignation(e.g.RON786C).theshaftsideoftheangleencoder—seeMatingDimensions)gives“+1”LinecountzNumberofNominalreferencemarksincrementI360007210°180003620°anseiertpProScanningtheMeasuringStandardPhotoelectricScanningMostHEIDENHAINencodersoperateusingtheprincipleofphotoelectricscanning.Photoelectricscanningofameasuringstandardiscontact-free,andassuch,freeofwear.Thismethoddetectsevenvery?nelines,nomorethanafewmicronswide,andgeneratesoutputsignalswithverysmallsignalperiods.The?nerthegratingperiodofameasuringstandardis,thegreatertheeffectofdiffractiononphotoelectricscanning.HEIDENHAINusestwoscanningprincipleswithangleencoders:?Theimagingscanningprincipleforgratingperiodsfrom10μmtoapprox.70μm.?Theinterferentialscanningprincipleforvery?negraduationswithgratingperiodsof4μm.14ImagingscanningprinciplePutsimply,theimagingscanningprinciplePhotovoltaiccellsconvertthesevariationsfunctionsbymeansofprojected-lightinlightintensityintoelectricalsignals.Thesignalgeneration:twograduationswithspeciallystructuredgratingofthescanningequalgratingperiodsaremovedrelativetoreticle?ltersthelightcurrenttogenerateeachother—thescaleandthescanningnearlysinusoidaloutputsignals.Thereticle.Thecarriermaterialofthescanningsmallertheperiodofthegratingstructurereticleistransparent,whereastheis,thecloserandmoretightlytolerancedgraduationonthemeasuringstandardmaythegapmustbebetweenthescanningbeappliedtoatransparentorre?ectivereticleandcircularscale.Practicalsurface.mountingtolerancesforencoderswiththeimagingscanningprincipleareachievedWhenparallellightpassesthroughawithgratingperiodsof10μmandlarger.grating,lightanddarksurfacesareprojectedatacertaindistance.AnindexTheRCN,RONandRODangleencodersgratingwiththesamegratingperiodiswithintegralbearingoperateaccordingtolocatedhere.Whenthetwogratingsmovetheimagingscanningprinciple.relativetoeachother,theincidentlightismodulated.Ifthegapsinthegratingsarealigned,lightpassesthrough.Ifthelinesofonegratingcoincidewiththegapsoftheother,nolightpassesthrough.ImagingscanningprincipleInterferentialscanningprincipleTheinterferentialscanningprincipleexploitsArelativemotionofthescanningreticletothediffractionandinterferenceoflightonathescalecausesthediffractedwavefronts?negraduationtoproducesignalsusedtotoundergoaphaseshift:whenthegratingmeasuredisplacement.movesbyoneperiod,thewavefrontofthe?rstorderisdisplacedbyonewavelengthAstepgratingisusedasthemeasuringinthepositivedirection,andthewavelengthstandard:re?ectivelines0.2μmhighareofdiffractionorder–1isdisplacedbyoneappliedtoa?at,re?ectivesurface.Infrontwavelengthinthenegativedirection.Sinceofthatisthescanningreticle—atransparentthetwowavesinterferewitheachotherphasegratingwiththesamegratingperiodwhenexitingthegrating,thewavesareasthescale.shiftedrelativetoeachotherbytwowavelengths.ThisresultsintwosignalWhenalightwavepassesthroughtheperiodsfromtherelativemotionofjustscanningreticle,itisdiffractedintothreeonegratingperiod.partialwavesoftheorders–1,0,and+1,withapproximatelyequalluminousInterferentialencodersfunctionwithintensity.Thewavesarediffractedbytheaveragegratingperiodsof4μmand?ner.scalesuchthatmostoftheluminousTheirscanningsignalsarelargelyfreeofintensityisfoundinthere?ecteddiffractionharmonicsandcanbehighlyinterpolated.orders+1and–1.ThesepartialwavesmeetTheseencodersarethereforeespeciallyagainatthephasegratingofthescanningsuitedforhighresolutionandhighaccuracy.reticlewheretheyarediffractedagainandEvenso,theirgenerousmountinginterfere.Thisproducesessentiallythreetolerancespermitinstallationinawidewavesthatleavethescanningreticleatrangeofapplications.differentangles.PhotovoltaiccellsconvertthisalternatinglightintensityintoelectricalTheRPN886angleencoderwithintegralsignals.bearingoperatesaccordingtotheinterferentialscanningprinciple.Interferentialscanningprinciple(opticsschematics)CGratingψperiodPhaseshiftofthelightwavewhenpassingthroughthescanningreticle?PhaseshiftofthelightwaveduetomotionXofthescaleMeasuringAccuracyTheaccuracyofangularmeasurementismainlydeterminedby:1.thequalityofthegraduation,2.thequalityofthescanningprocess,3.thequalityofthesignalprocessingelectronics,4.theeccentricityofthegraduationtothebearing,5.theradialrunoutofthebearing,6.theelasticityoftheencodershaftanditscouplingwiththedriveshaft,7.theelasticityofthestatorcoupling(RCN,RON,RPN)orshaftcoupling(ROD)Inpositioningtasks,theaccuracyoftheangularmeasurementdeterminestheaccuracyofthepositioningofarotaryaxis.ThesystemaccuracygivenintheSpeci?cationsisde?nedasfollows:Theextremevaluesofthetotalerrorofaposition—withrespecttothemeanvalue—arewithinthesystemaccuracy±a.Thetotalerrorisascertainedatconstanttemperatures(22°C)duringthe?nalinspectionandareindicatedonthecalibrationchart.?Forangleencoderswithintegralbearingandintegratedstatorcoupling,thisvaluealsoincludesthedeviationduetotheshaftcoupling.?Forangleencoderswithintegralbearingandseparateshaftcoupling,theangleerrorofthecouplingmustbeadded(seeMechanicalDesignTypesandMounting–ROD).?Forangleencoderswithoutintegralbearing,additionaldeviationsresultingfrommounting,errorsinthebearingofthedriveshaft,andadjustmentofthescanningheadmustbeexpected(seecatalog:AngleEncoderswithoutIntegralBearing).Thesedeviationsarenotre?ectedinthesystemaccuracy.Thesystemaccuracyre?ectspositionerrorswithinonerevolutionaswellasthosewithinonesignalperiod.Positionerrorwithinonerevolutionbecomesapparentinlargerangularmotions.Positiondeviationswithinonesignalperiodalreadybecomeapparentinverysmallangularmotionsandinrepeatedmeasurements.Theyespeciallyleadtospeedripplesinthespeedcontrolloop.Thesedeviationswithinonesignalperiodarecausedbythequalityofthesinusoidalscanningsignalsandtheirsubdivision.Thefollowingfactorsin?uencetheresult:?Thesizeofthesignalperiod?Thehomogeneityandedgede?nitionofthegraduation?Thequalityoftheoptical?lterstructuresonthescanningreticle?Thecharacteristicsofthephotoelectricdetectors?ThestabilityanddynamicsduringthefurtherprocessingoftheanalogsignalsHEIDENHAINangleencoderstakethesefactorsofin?uenceintoaccount,andpermitinterpolationofthesinusoidaloutputsignalwithsubdivisionaccuraciesofbetterthan±1%ofthesignalperiod(RPN:±1.5%).Thereproducibilityisevenbetter,meaningthatusefulelectricsubdivisionfactorsandsmallsignalperiodspermitsmallenoughmeasuringsteps(seeSpeci?cations).Example:Angleencoderwith36000sinusoidalsignalperiodsperrevolutionOnesignalperiodcorrespondsto0.01°or36“.Withasignalqualityof±1%,thisresultsinmaximumpositionerrorwithinonesignalperiodofapprox.±0.0001°or±0.36“.ForitsangleencoderswithintegralAllmeasuredvaluesdeterminedinthisThefollowinglimitsapplytothereversalbearings,HEIDENHAINpreparesindividualmannerliewithinoronthegraphicallyerror:calibrationchartsandshipsthemwiththedepictedenvelopecurve.ThemeanvalueRCN/RON2xx:Max.0.6“encoder.ThecalibrationchartdocumentscurveshowsthearithmeticmeanoftheRCN/RON7xx:Max.0.4“theencoder’saccuracyandservesasameasuredvalues,inwhichthereversalRCN/RON/RPN8xx:Max.0.4“traceabilityrecordtoacalibrationstandard.errorisnotincluded.FortheRCN,RONandRPN,whichfeatureThemanufacturer’sinspectioncerti?cateanintegratedcoupling,theaccuracyThereversalerrordependsontheshaftcerti?estheaccuracyoftheencoder.Thespeci?cationsalreadyincludetheerrorofcoupling.Onangleencoderswithintegralcalibrationstandardisindicatedinorderthecoupling.Forangleencoderswithstatorcouplingitisdeterminedattentocertifythetraceabilitytothenationalseparateshaftcoupling,however,theerrormeasuringpositionsinforwardandstandard.causedbythecouplingisnotincludedinbackwardsteps.Themaximumvalueandtheencoderspeci?cationandmustbearithmeticmeanaredocumentedontheaddedtocalculatethetotalerror(seecalibrationchart.MechanicalDesignTypesandMounting–ROD–Kinematicerroroftransfer).DeterminationofthereversalerrorwithforwardandbackwardmeasurementsThesystemaccuracyofangleencodersisascertainedthrough?veforwardand?vebackwardmeasurements.Themeasuringpositionsperrevolutionarechosentodetermineveryexactlynotonlythelong-rangeerror,butalsothepositionerrorwithinonesignalperiod.Calibrationchartexample:RON2851Graphicrepresentationoferror?Envelopecurve?Meanvaluecurve2ResultsofcalibrationMechanicalDesignTypesandMountingRCN,RON,RPNRCN,RONandRPNangleencodershaveanintegralbearing,hollowshaftandintegratedstatorcoupling.Themeasuredshaftisdirectlyconnectedwiththeshaftoftheangleencoder.Thereferencemarkcanbeassignedtoadesiredangularpositionofthemeasuredshaftfromtherearoftheencoderduringmounting.Design:Thegraduateddiskisrigidlyaf?xedtothehollowshaft.Thescanningunitridesontheshaftonballbearingsandisconnectedtothehousingwithacouplingonthestatorside.Duringangularaccelerationoftheshaft,thecouplingmustabsorbonlythattorquecausedbyfrictioninthebearing.Angleencoderswithintegratedstatorcouplingthereforeprovideexcellentdynamicperformance.MountingThehousingoftheRCN,RONandRPNis?rmlyconnectedtothestationarymachinepartwithanintegralmounting?angeandacenteringcollar.Liquidscaneasily?owawaythroughdrainagechannelsonthe?ange.ShaftcouplingwithringnutTheRCN,RONandRPNserieshaveahollowthroughshaft.Forinstallation,thehollowthroughshaftoftheangleencoderisplacedoverthemachineshaft,andis?xedwitharingnutfromthefrontoftheencoder.Theringnutcaneasilybetightenedwiththemountingtool.FrontendshaftcouplingItisoftenhelpful,especiallywithrotarytables,tointegratetheangleencoderinthetablesothatitisfreelyaccessiblewhentherotorislifted.Thisinstallationfromabovereducesmountingtimes,increasestheeaseforservicing,andimprovestheaccuracy,sincetheencoderislocatednearertotherotarytablebearingandthemeasuringormachiningplane.Thehollowshaftisconnectedbythreadedholesonthefacewiththeaidofspecialmounting(notincludedindelivery).Tocomplywithradialandaxialrunoutspeci?cations,theinternalboreshouldersurface2aretobeusedas1faceoftheencoder.RON905shaftcouplingTheRON905hasablindhollowshaft.shaftisconnectedbyanaxialcentralscrew.CrosssectionoftheRON886angleencoderMountinganangleencoderwithhollowthroughshaftFront-endshaftcouplingwithRCN729RingnutsforRCN,RONandRPNHEIDENHAINoffersspecialringnutsfortheRCN,RONandRPNangleencoderswithintegralbearingandhollowthroughshaftwithintegratedcoupling.Choosethetoleranceoftheshaftthreadsuchthattheringnutcanbetightenedeasily,withaminoraxialplay.Thisguaranteesthattheloadisevenlydistributedontheshaftconnection,andpreventsdistortionoftheencoder’shollowshaft.RingnutforRON/RCN200Hollowshaft?20mm:ID336669-03RingnutforRON785Hollowshaft?50mm:ID336669-05RingnutforRON786;RON/RPN886RCN72x/RCN82xHollowshaft?60mm:ID336669-11RingnutforRCN72x/RCN82xHollowshaft?100mm:ID336669-16MountingtoolforHEIDENHAINringnutsThemountingtoolisusedtotightentheringnut.Itspinslockintotheholesintheringnuts.Atorquewrenchprovidesthenecessarytighteningtorque.MountingtoolforringnutswithHollowshaft?20mmID530334-03Hollowshaft?50mmID530334-05Hollowshaft?60mmID530334-11Hollowshaft?100mmID530334-16PWWinspectiontoolforangleencodersThePWWmakesasimpleandquickinspectionofthemostsigni?cantmatingdimensionspossible.Theintegratedmeasuringequipmentmeasurespositionandradialrunoutregardlessofthetypeofshaftcoupling,forexample.PWWforHollowshaft?20mm:ID516211-01Hollowshaft?50mm:ID516211-02Hollowshaft?60mm:ID516211-03Hollowshaft?100mm:ID516211-05RingnutforSeriesRxN200RingnutforRxN700/800seriesInspectiontoolPWWHYPERLINK"/retype/zoom/3c5ab2f0770bf78a6529548f?pn=19&x=0&y=511&raww=384&rawh=249&o=png_6_0_0_0_0_0_0_892.83_1263&type=pic&aimh=249&md5sum=04cb0208dbb3d22505df81594338613c&sig