Bevel Gears in ProE

8/2/2019 Bevel Gears in ProE

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Table of Contents:

TableofContents:............................................................................................................................. i Disclaimer ........................................................................................................................................1 Preamble .........................................................................................................................................1 DevelopmentFlowChart..................................................................................................................2 BevelGearFoundation ....................................................................................................................2 Setup............................................................................................................................................2 TemplateParameters ...............................................................................................................2 Relations...................................................................................................................................3

Straight/SpiralToothBase .............................................................................................................3 ToothDatums...............................................................................................................................3 ToothCoordinateSystem[TCSYS] ..........................................................................................3 ToothDatumPlanes .................................................................................................................3 SectionDatumPointLayout[SDP] ...........................................................................................3

SpiralGearSpecificFeatures ..........................................................................................................5 PitchConeSurface[PCS] ............................................................................................................5 SpiralPlaneAxis[SPA] ................................................................................................................6 SpiralAnglePlane[SAP]..............................................................................................................6 PostFeatureCreation...............................................................................................................7

SpiralCurvePath .........................................................................................................................7 Geometry ..................................................................................................................................8

ProjectontoPitchCone................................................................................................................8 References ...............................................................................................................................9

SpiralCurveDatumPoints[S#CDP] ............................................................................................9 References ...............................................................................................................................9

SectionCoordinateDatums .............................................................................................................9 Primary[SXPCSYS] .....................................................................................................................9 References ...............................................................................................................................9

Secondary[S#SCSYS]...............................................................................................................10

Relation...................................................................................................................................10 Tertiary[S#TCSYS]....................................................................................................................10 Relation...................................................................................................................................10

ProtoTooth ....................................................................................................................................10 SectionCurves...........................................................................................................................10 ParametricEquations..............................................................................................................10 InvoluteCurve[S#C{1;3}] .......................................................................................................10 Side(AxistoInvolute)Curve[S#C{2;4}] .................................................................................11

GroupSectionFeatures .............................................................................................................11



ii

SideSurface[T{L/R}S] ...............................................................................................................11 RevolvedTubeSurface[RTS]....................................................................................................12 StraightToothGears:..............................................................................................................12 SpiralToothGears:.................................................................................................................12 SketchReferences:.................................................................................................................12 Geometry ................................................................................................................................12

SurfaceMerge...........................................................................................................................12 FirstFeature ...........................................................................................................................13 SecondFeature ......................................................................................................................13

SolidTooth .................................................................................................................................13 GearTemplate...............................................................................................................................13 UsingtheTemplates ......................................................................................................................14 InitialModification.......................................................................................................................14 Pinion/Miter ..............................................................................................................................14 ToothGroup............................................................................................................................14 Pattern ....................................................................................................................................14 Core........................................................................................................................................15

Gear ...........................................................................................................................................17 GearTooth..............................................................................................................................17 GearPartAssembly................................................................................................................17 GearCore...............................................................................................................................17 Merge......................................................................................................................................18

MatingPairs ...................................................................................................................................18 AssemblySetup .........................................................................................................................18 ExistingShafts........................................................................................................................18 FirstParts ...............................................................................................................................18

AngleModification......................................................................................................................19 ModifyingGears.............................................................................................................................19 ZerolBevelGears ......................................................................................................................19 Crowning ....................................................................................................................................19



1

Disclaimer

Thetemplates,suppliedwithorcreatedusingthisdocument,areintendedfortechnicalillustrativepurposesonly.Theauthorlaysnoclaimthattheresultingmodelsaretruerepresentationsofbevelgearsproducedbygearmanufacturers.

Preamble

Duringthedevelopmentofthismethod,theauthordiscoveredaproblemwithinthePro/ENGINEERWildfiresoftware.Whenmodifyingtheparameterstocreategears,thesurfacemergefeaturesfail.Fixingthisandthentryingtopatternthetooth,themergesfailagain.Pitchconeanglesgreaterthan45°leadtofailures.Aworkaroundwasdevisedtocircumventtheproblem.

TheauthorinitiallyusedEmptyfilestocreatealltemplates.Allpartdatumfeatures,coordinatesystemanddatumplanesweregeneratedandrenamedinaccordancetothenamingconventiondisplayedinthisdocument.Anydefaultsketchreferencesweredeleted.



2

Development Flow Chart

Bevel Gear CoreBevel GearFoundation

Bevel Gear Part Assembly

Straight ToothBase

Spiral ToothBase

Left-Hand Right-HandCup Face ToothPinion

Flat Faced ToothPinion

Cup Face ToothGear

Cup Face ToothPinion

Flat Faced ToothPinion

Cup Face ToothGear

Cup Face ToothPinion Flat Faced ToothPinion

Cup Face ToothGear

Bevel Gear Foundation

SETUP

Template Parameters

ParameterName

TypeInitial Value

Designate Where Used

Tooth Parameters Pinion Gear(Assy) Gear(Core)DIAMETRAL_PITCH Real Number 10 ● ●

NUMBER_OF_TEETH Integer 20 ● ● ●

NUMBER_OF_TEETH_MG Integer 20 ● ●

FACE_WIDTH Real Number 0.5 ● ●

PRESSURE_ANGLE Real Number 20 ●

SHAFT_ANGLE Real Number 90 ● ●

SPIRAL_ANGLE Real Number 30 ●

CLEARANCE Real Number 0.01 ● ●

Gear Blank ParametersMOUNTING_DISTANCE Real Number 0 ● ●

BORE_DIAMETER Real Number 0 ● ●

BORE_LENGTH Real Number 0 ● ●

HUB_DIAMETER Real Number 0 ● ●

HUB_LENGTH Real Number 0 ● ●

APEX_TO_BACK Real Number 0 ● ●

BOLT_CIRCLE Real Number 0 ● ●

THROUGH_HOLE Real Number 0 ●

NUMBER_OF_HOLES Integer 0 ●

CBORE_DIAMETER Real Number 0 ● ●

CBORE_DEPTH Real Number 0 ● ●WEB_THICKNESS Real Number 0 ● ●



3

FigureFigureFigureFigure1111:ToothCoordinateSystemDefinition:ToothCoordinateSystemDefinition:ToothCoordinateSystemDefinition:ToothCoordinateSystemDefinition

Relations

Straight / Spiral Tooth Base

TOOTH DATUMS

Thesearetheinitialdatumfeaturesusedintheprimarytooth’sdevelopment.

Tooth Coordinate System [TCSYS]

Thiscoordinatesystemistheonlyconnectionfortheprimarytoothtotherestofthemodel. Allfurtherdatumsandgeometrywillbebasedoffofthisfeature.Thesinglenon-zerodimensionisusedforcreatingthetoothpattern.

UsethePartCSYS[PCSYS]asthereference.RotatethefeatureabouttheZ-axisanarbitraryangle.

Note:Note:Note:Note:Unlessotherwisenoted,theauthoruses30°forallarbitraryangles.

SeeFigure1

Tooth Datum Planes

Therearethreedatumplanesneededforreferencinglaterfeaturesandgeometry.Theyhaveazero(0)offsetalongeachaxisoftheTCSYScoordinatesystem.

• X [TYZPLN]

• Y [TXZPLN]

• Z [TXYPLN]

Section Datum Point Layout [SDP]

ThisisaSketchedDatumPointfeature.Thisfeaturecontainsthepointsandreferencedimensionsnecessarytocreatethepropertoothcross-sections.

ThesketchingplaneistheTYZPLNplaneandthetopreferenceistheTXZPLNplane.

CUTTER_DIAMETER=(NUMBER_OF_TEETH+NUMBER_OF_TEETH_MG)/(2*DIAMETRAL_PITCH)

IF NUMBER_OF_TEETH_MG>NUMBER_OF_TEETHPITCH_CONE_ANGLE=ATAN(SIN(SHAFT_ANGLE)/((NUMBER_OF_TEETH_MG/NUMBER_OF_TEETH)+COS(SHAFT_ANGLE)))ELSEPITCH_CONE_ANGLE=SHAFT_ANGLE-

ATAN(SIN(SHAFT_ANGLE)/((NUMBER_OF_TEETH/NUMBER_OF_TEETH_MG)+COS(SHAFT_ANGLE)))

ENDIF

PITCH_DIAMETER=NUMBER_OF_TEETH/DIAMETRAL_PITCH ADDENDUM=DIAMETRAL_PITCH^-1DEDENDUM=CLEARANCE+ADDENDUMPITCH_CONE_RADIUS=PITCH_DIAMETER/(2*SIN(PITCH_CONE_ANGLE))

ADDENDUM_ANGLE=ATAN(ADDENDUM/PITCH_CONE_RADIUS)DEDENDUM_ANGLE=ATAN(DEDENDUM/PITCH_CONE_RADIUS)

ANGULAR_ADDENDUM=ADDENDUM*COS(PITCH_CONE_ANGLE)OUTER_DIAMETER=PITCH_DIAMETER+(2*ANGULAR_ADDENDUM)FACE_ANGLE=PITCH_CONE_ANGLE+ADDENDUM_ANGLEROOT_ANGLE=PITCH_CONE_ANGLE-DEDENDUM_ANGLE

VERTEX_DISTANCE=OUTER_DIAMETER/(2*TAN(FACE_ANGLE))

PHI=((180/PI)*(TAN(PRESSURE_ANGLE)-(PRESSURE_ANGLE*PI/180)))/COS(PITCH_CONE_ANGLE)TCRA=(90/NUMBER_OF_TEETH)+PHI



4

FigureFigureFigureFigure2222:BasicToothDimensions:BasicToothDimensions:BasicToothDimensions:BasicToothDimensions

FigureFigureFigureFigure3333:SpiralPitchPints:SpiralPitchPints:SpiralPitchPints:SpiralPitchPints

Note:Note:Note:Note:Forall“sideview”sketches,theauthordoesnotusethedefaultreferences.Theusercanusethedefaults,ifsodesired,andmodifythesubsequentinstructionsaccordingly.

ThereferenceforthesketchitselfistheTCSYScoordinatesystem.

SKETCH

CreateaHorizontalConstructionLine(CL)throughtheTCSYS;thisisthegear’s‘RotationAxis’.

Next,createonemore,angledthroughtheTCSYSfromthelowerlefttotheupperright;thisisthe

gear’s‘PitchLine’(PL).ThedimensionshouldbeangularandbasedfromtheHorizontalCL.ModifythevaluetoberelatedtothePITCH_CONE_ANGLE(PCA).

POINTS ALONG PITCH LINE

HeelPitchPoint HeelPitchPoint HeelPitchPoint HeelPitchPoint

PlaceasketchpointontheupperportionofthePL.ModifytheWeakDimensiontoberelatedtoPITCH_DIAMETER/2.

ToePitchPoint ToePitchPoint ToePitchPoint ToePitchPoint

PlaceanotherpointonthePLbetweentheheelpointandtheTCSYS.Thisistobe

dimensionedfromheelpointalignedwiththePL.ThedimensionvalueisequaltotheFACE_WIDTH(FW)[sd3 ].

Atthispointintheconstruction,thefourvariancesbegintodiverge.

SeeFigure2.

InternalPoints InternalPoints InternalPoints InternalPoints

Note:Note:Note:Note:ThesearenotrequiredfortheStraightToothedgears.

TheinternalpointsareusedforthecreationofadditionalsectionssothatSpiralGearsaregeneratedwithasmootherprofile.

FortheSpiralGears,placethree(3)pointsbetweentheHeelandToepoints.SeeFigure3.DimensionbetweenthemalignedtothePLwiththedimensionsequaltoFW/4.Theinitialrelationcanbeequaltosd3/4 andthetwo(2)successivedimensionsequaltotheinitial.

ExternalPoints ExternalPoints ExternalPoints ExternalPoints

Theexternalpointsallowthesidesurfacestoextendpasttherevolvedsurfacefeaturetobecreatedlater.Thiscanbethenextmajordifferentiationpointinthedevelopment,butthesingledimensionalmodificationcanbeperformedatalatertime.Thisallowsforamorestraightforwarddevelopment.

OnepointistobeplacedalongthePLontheoutsideoftheHeelpoint.Thealigneddimensionisequaltosd3/4 ,thesameastheInternalPointsabove.

AnotherpointislocatedalongthePLbetweentheToepointandTCSYS.Thisisthedimensionthatneedstodifferentiate.ForParallelteeth,thedimensionisthetypicalFW/4 .

SeeFigures3&4.



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FigureFigureFigureFigure4444:StraightPitchPoints:StraightPitchPoints:StraightPitchPoints:StraightPitchPoints

FigureFigureFigureFigure6666:CompletedSpiralSketch:CompletedSpiralSketch:CompletedSpiralSketch:CompletedSpiralSketch

FigureFigureFigureFigure5555:CompletedStraightSketch:CompletedStraightSketch:CompletedStraightSketch:CompletedStraightSketch

FLAT FACE TOOTH EXCEPTION

Toallowforthetoothsidestopassthroughtherotatedtoeendsurface,thisdimensionmustbedoubledtoFW/2 .Asstatedbefore,thiscanbemodifiedpost,deviation,aftertheclosedrotatedsurfaceisgenerated.

POINTS ALONG REVOLUTION AXIS

ConstructionLines ConstructionLines ConstructionLines ConstructionLines

Theconstructionlinesdeterminethelocationofthedatumpointsthatfollow.Thepoints,inturn,willbethelocationmarkersfortheprimarycoordinatesystemusedtogeneratetheinvolutecurves.

AllconstructionlinesareNormaltothePL.

ForStraightToothGears,onlytheouterpointsalongthePLareused.

ForSpiralToothGears,thelinespassthrougheachpointalongthePLisused.Points Points Points Points

AsketchpointisplacedateveryintersectionoftheConstructionLinesandHorizontalCL.

REFERENCE DIMENSIONS

Theequationusedindeterminingthebaseradiusoftheinvoluterequiresthepitchdiameter.Theteetharenotorientedonacylinder,butratheracone.Thesedimensionssimplifythedevelopment,bygivingtheproper,required“pitchradius”forthesections.

Goto:Sketch>Dimension>Reference.DimensionbetweencorrespondingpointsandalignedtotheCL.

SeeFigures5&6.

Spiral Gear Specific Features

PITCH CONE SURFACE [PCS]

ThisisaRRRRevolvedevolvedevolvedevolvedSurfaceFeatureSurfaceFeatureSurfaceFeatureSurfaceFeature.Itisrevolvedthrough90°includedangleonBothSidesBothSidesBothSidesBothSides.

Forthesketchplacement:UsePrevious .

ThesketchreferencesaretheTCSYSandtheouter-mostdatumpointsalongthepitchline.



6

FigureFigureFigureFigure9999:SpiralPlaneAxis:SpiralPlaneAxis:SpiralPlaneAxis:SpiralPlaneAxis

FigureFigureFigureFigure10101010:SpiralAnglePlane:SpiralAnglePlane:SpiralAnglePlane:SpiralAnglePlane

FigureFigureFigureFigure7777:CompletedPCSSketch:CompletedPCSSketch:CompletedPCSSketch:CompletedPCSSketch

FigureFigureFigureFigure8888:PitchConeSurface:PitchConeSurface:PitchConeSurface:PitchConeSurface

ThissketchconsistsofahorizontalconstructionlinethroughtheTYSCSandageometrylinebetweentheexternalendpoints.SeeFigures7&8.

SPIRAL PLANE AXIS [SPA]

ThisfeatureisusedtoproperlylocatetheSpiralPlane.

CreateaDatumAxisthroughthemiddledatumpointalongPitchLineandnormaltothePCS.

SeeFigure9.

SPIRAL ANGLE PLANE [SAP]

Thisfeatureisusedtoproperlyorientthesketchgeometrythatwillbecomethecurvepath.

PlacetheplanethroughtheSPAandangledfromtheTYZPLNplane,thedefaultvalueOK.

NexteditthedimensionsothatitisequaltotheSPIRAL_ANGLEparameter.

SeeFigure10.



7

FigureFigureFigureFigure11111111:SpiralCurveSketchPlane:SpiralCurveSketchPlane:SpiralCurveSketchPlane:SpiralCurveSketchPlane

FigureFigureFigureFigure12121212:SpiralCurveSketchPlane:SpiralCurveSketchPlane:SpiralCurveSketchPlane:SpiralCurveSketchPlane

Post Feature Creation

DuetothegeometryoftheSpiralcurveisbestatthisjuncturetodivergethemodelintotheLeftHand/RightHandspirals.

• Save the file.

• Save a copy to indicate the proper hand, as indicated by the current SAP orientation.

• Comment out the SPIRAL_ANGLE relation, place “/*” at the start of line containing the relation.

• Edit Feature and add a negative “-” sign in front of the value.

• Regenerate.

• Remove the comment, delete the “/*”.

• Save a copy to indicate the new SAP orientation.

• Erase the template from memory.

• Open one of the diverged models.

SPIRAL CURVE PATH

Theactualcurveisanarcsegment,whichisprojectedontothePCS.UsetheSketchToolto

createthesketch[SPCRVSKTCH].Thesketchplaneismade‘onthefly’.Usethefollowing,intheorderindicated,tocreateit.

1. Middle SDP Point along the Pitch Cone - Thorough (default)

2. TYZPLN - Normal

3. Pitch Cone - Tangent

TheorientationreferenceshoulddefaulttotheTYZPLN.ThisisOK.

SeeFigures11&12.



8

FigureFigureFigureFigure14141414:CompletedSpiralCurveSketch:CompletedSpiralCurveSketch:CompletedSpiralCurveSketch:CompletedSpiralCurveSketch(Right(Right(Right(Right----Hand)Hand)Hand)Hand)

FigureFigureFigureFigure13131313:SpiralCurveReferences:SpiralCurveReferences:SpiralCurveReferences:SpiralCurveReferences

FigureFigureFigureFigure15151515SectionSectionSectionSectionGroupingGroupingGroupingGrouping

SketchReferences

Thefollowingisalistforthesketchreferences.

• SPA or middle SDP point

• SAP

• Inner Arc Edge of PCS

SeeFigure13.

Geometry

PlaceaConstructionLinethroughtheSPA/middleSDPreferenceandnormaltotheSAPreference.

PlaceacirclecenteredontheCLsothatthecenterislocatedonthearccenterreferencesideoftheSAP.ThecirclecanbeeitherTangenttotheSAPorcoincidentwiththeSPAreferencepoint.

Thediameterdimensionisequalto:CUTTER_DIAMETER.Convertthecircleintoconstructiongeometry,RMB>Construction.

CreateanOffsetsegmentusingtheouterPCSedge.Theoffsetdistanceisequalto:2*CLEARANCE.Thiswillallowthearcsegmenttointersecttheouteredgewhenprojectedontoit.

Note:Note:Note:Note:Thiscannotbeconvertedintoconstructiongeometry.

Next,drawanarcconcentrictotheConstructionCirclebetweentheintersectionsoftheConstructionCircleandtheinnerarcreferenceandtheoffsetsegment.

Thesketchiscomplete.SeeFigure14.

PROJECT ONTO PITCH CONE

ThesketchnowneedstobeprojectedontothePCS.SelectEditEditEditEdit>>>>PPPProjectrojectrojectrojectfromthePull-DownMenu(PDM).

ThetypeofitemtobeprojectedisCURVE.Selecttheconcentricarcfromsketchfeature.

Forthedirection,selectNormaltosurfaceandselectthePCS.

SpecialNote:SpecialNote:SpecialNote:SpecialNote:Fromthispointon,itisbesttocreateeachsection(markedwithS#...)independentlyfromtheothersections.

SeeFigure15.



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FigureFigureFigureFigure16161616:SectionPlane(TYP):SectionPlane(TYP):SectionPlane(TYP):SectionPlane(TYP)

FigureFigureFigureFigure17171717:SpiralCurveDatumPoint(TYP):SpiralCurveDatumPoint(TYP):SpiralCurveDatumPoint(TYP):SpiralCurveDatumPoint(TYP)

FigureFigureFigureFigure18181818:PrimaryCSYSReferences:PrimaryCSYSReferences:PrimaryCSYSReferences:PrimaryCSYSReferences

SectionPlanes[S#PDP]

Thisfeaturesetsupthedatumpointusedtoorienttheprimarycoordinatesystem.

References

SelecttheSectionPitchLinePoint(SDP)thentheTXZPLN.Itshoulddefaulttothroughandparallelrespectively.

EXCEPTION

FortheCenter,FW/2,point,thisfeatureisnotcreated;thepointisthereference.

SeeFigure16.

SPIRAL CURVE DATUM POINTS [S#CDP]

Thisisusedtoorientthesection’sprimarycoordinatesystem’s‘X’axis.

References

SelecttheS#PDPandtheSpiralCurvePath.

Note:Note:Note:Note:TheS#PDPshouldautomaticallybeselectedifcreatedimmediatelyafteritscreation.

EXCEPTION

FortheCenter,FW/2,point,thisfeatureisnotcreated;thepointisthereference.

SeeFigure17.

ThisconcludestheSpiralGearSpecificFeaturecreation.

Section Coordinate Datums

Therearethree(3)coordinatesystemsneededtocreatethetooth.Thesecondaryandtertiaryarecopiesoftheprimary.

PRIMARY [SXPCSYS]

References

TheOriginforallPCSYS’sisthecorrespondingAxial

DatumPointfromtheSDPfeature.

Thepositive‘X’directionissetusingthe:

STRAIGHT TOOTH GEARS

CorrespondingSDPpointalongPitchLine

SPIRAL TOOTH GEARS

CorrespondingPrimaryDatumPlane/CurvePoint,S#CDP

Thepositive‘Z’directionissetusingtheZ-axisoftheTCSYS.

SeeFigure18&19.



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FigureFigureFigureFigure19191919:SectionPrimaryCoordinateSystem:SectionPrimaryCoordinateSystem:SectionPrimaryCoordinateSystem:SectionPrimaryCoordinateSystem

SECONDARY [S#SCSYS]

ThisisaRotatedCopyofthePCSYS.SelectEEEEditditditdit>F>F>F>FeatureeatureeatureeatureOOOOperationsperationsperationsperationsfromthePDM.SelectCCCCopy,opy,opy,opy,thenMMMMoveoveoveove////DependentDependentDependentDependent////DDDDoneoneoneone.

PicktheS#PCSYSthenDDDDoneoneoneone.SelectRRRRotateotateotateotate////CCCCSYSSYSSYSSYSandpicktheTCSYS.SelectZZZZaxisaxisaxisaxis////OOOOkaykaykaykay.

Enteranarbitraryangle.SelectDDDDoneoneoneoneMMMMoveoveoveovethenDDDDoneoneoneone////OKOKOKOK.

Relation

EditthefeatureandsetthedimensionvalueequaltoTCRA(relationequation).

TERTIARY [S#TCSYS]

ThisisaRotatedCopyofthePCSYS.SelectEEEEditditditdit>F>F>F>FeatureeatureeatureeatureOOOOperationsperationsperationsperationsfromthePDM.SelectCCCCopy,opy,opy,opy,thenMMMMoveoveoveove////DDDDependentependentependentependent////DDDDoneoneoneone.

PicktheS#TCSYSthenDDDDoneoneoneone.SelectRRRRotateotateotateotate////CCCCSYSSYSSYSSYSandpicktheTCSYS.SelectZZZZaxisaxisaxisaxis////FFFFliplipliplip

/O/O/O/Okaykaykaykay.Enteranarbitraryangle.SelectDDDDoneoneoneoneMMMMoveoveoveovethenDDDDoneoneoneone////OKOKOKOK.

Relation

EditthefeatureandsetthedimensionvalueequaltoTCRA(relationequation).

Proto Tooth

Foreachsection,regardlessoftoothtype,therearefour(4)curvestobegenerated.

SECTION CURVES

Theauthoremployedthefollowingstrategy.TheinvolutecorrespondingtotheS#SCSYSwas

created,followedbythesidecurve.Thiswasrepeatedfortheoppositeside.Thecurvesarenumbered1through4.

Parametric Equations

Hint:Hint:Hint:Hint:Entertheequationsintoatextdocumentforeasyaccess.

Involute Curve [S#C{1;3}]

CreatethisfeaturewiththeDDDDatumatumatumatumCCCCurveurveurveurve>FromEquat>FromEquat>FromEquat>FromEquationionionionoption.

SelectthecoordinatesystemfromthemodeltreeandusetheCartesianCartesianCartesianCartesianequationstyle.

FortheS#SCSYS:

Enterequations,substitutingthesection’scorrespondingSDPreferencedimensionfortheD##inthe‘R=D##…’part.Adanegativesign(-)infrontofthe‘R’forthe‘Y’equationsothatitresembles‘Y=-R…’

FortheS#TCSYS:

R=D##*COS(PRESSURE_ANGLE)

THETA=T*45THETA_RAD=PI/180*THETA

X=R*(COS(THETA)+(THETA_RAD*SIN(THETA))) Y=R*(SIN(THETA)-(THETA_RAD*COS(THETA)))



11

FigureFigureFigureFigure20202020:SideCurveCreation:SideCurveCreation:SideCurveCreation:SideCurveCreation

FigureFigureFigureFigure21212121:SideCurveTangency:SideCurveTangency:SideCurveTangency:SideCurveTangency

FigureFigureFigureFigure22222222:SideSurfaceSelection(TYP):SideSurfaceSelection(TYP):SideSurfaceSelection(TYP):SideSurfaceSelection(TYP)

The‘D##’isthesameasaboveforthesectionbeingcreated.Thenegativesign(-)isnotappliedinthisinstance.

Side (Axis to Involute) Curve [S#C{2;4}]

ThisiscreatedwiththeDatumCurve>ThruPointsDatumCurve>ThruPointsDatumCurve>ThruPointsDatumCurve>ThruPointsoption.ThereferencesarefromthecorrespondingAxialDatumPointfromtheSDPfeaturetotheinnerendpointoftheInvoluteCurve.

SeeFigure20.

Tangencycanbeapplied,selectingEndEndEndEndfromthemenuandpicktheinvolutecurve.Thetangencyarrowshouldpointawayfromtherotationaxis.

SeeFigure21.

GROUP SECTION FEATURES

Fororganizationalpurposes,itisagoodpracticetogroupspecificsectionfeaturestogether.

ForStraightToothedgears,grouptheCoordinateSystemsplustheCurves.

ForSpiralToothedgears,groupallfeaturesfromtheS#PDPtoS#C4.

Collapsethecopiedcoordinatesystemsifnecessary.

Hint:Hint:Hint:Hint:Hidingthegroupaftercreationallowseasiervisibilitywhenconstructingproceedingsections.

SIDE SURFACE [T{L/R}S]

Forthesesurfaces,usetheInsert>Blend>SurfaceInsert>Blend>SurfaceInsert>Blend>SurfaceInsert>Blend>Surface

optionfromthePDM.UsetheGeneralGeneralGeneralGeneral;SelectSecSelectSecSelectSecSelectSec;andSmoothSmoothSmoothSmoothselectionstodefinethefeature.

Foreachsection,selectadjoiningcurves.Repeatasnecessary.Thenrepeatfortheoppositeside.

Hint:Hint:Hint:Hint:SelectingtheSideCurvefirsteliminatestheneedtomodifythestartpoints.

SeeFigure22.



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FigureFigureFigureFigure24242424:CompletedCupFacedToothSketch:CompletedCupFacedToothSketch:CompletedCupFacedToothSketch:CompletedCupFacedToothSketch

FigureFigureFigureFigure23232323:CompletedFlatFacedToothSketch:CompletedFlatFacedToothSketch:CompletedFlatFacedToothSketch:CompletedFlatFacedToothSketch

REVOLVED TUBE SURFACE [RTS]

Thisfeaturesetsupthesurfaceinwhichthesidesurfacesenclosetobecomethesolidtooth.ItisaRevolvedRevolvedRevolvedRevolvedSuSuSuSurfacerfacerfacerfaceFeatureFeatureFeatureFeaturerevolvedthrough90°onBothSidesBothSidesBothSidesBothSides.

ForthePlacement:

Straight Tooth Gears:

PicktheUsePrevious option.

Spiral Tooth Gears:

ThesketchplaneisdefinedastheTYZPLN,withthetopreferenceastheTXZPLN.

Sketch References:

• TCSYS

• Heel Pitch Point (PITCH_DIAMETER/2)

• Toe Pitch Point (FACE_WIDTH)

Geometry

DrawaConstructionLine(CL)horizontallythroughtheTYSCSreferencepoint.PlaceanotherCL

throughbothPitchPoint(PP)references;thisdefinesthePitchLine. AddadditionalCLsthrougheachPPthatarenormaltothePitchLine.

OnthenormallinethroughtheheelPP,placeoneSketchPointabovethePitchLineandonebelow.DimensionthepointsfromthePitchLine.Theupperdimensionisequaltothe ADDENDUM.ThelowerisequaltotheDEDENDUM.

Througheachpoint,makeaCLatananglewithnootherconstraints.TheweakdimensionsshouldbeangularfromthehorizontalCL.Modifytheupperpoint’sdimensiontobeequaltotheFACE_ANGLEandthelowerequaltotheROOT_ANGLE.

TraceageometrylinebetweenthesketchpointsandalongthefaceangleCLtotheintersection

withthetoePPnormalCL. Atthispoint,thegeometrydiffersforeachtoothtype.

CUP FACE TOOTH

DrawalinealongtheCLtowardstherootangleCL.

SeeFigure23.

Tip:Tip:Tip:Tip:Azoominmayberequiredforproperlyconstrainingthegeometry.

FLAT FACE TOOTH

DrawalineverticallydowntowardsrootangleCL.

SeeFigure24.ClosethegeometrybydrawingalinealongtherootangleCLtothededendumpoint.



13

FigureFigureFigureFigure25252525:FirstSurfaceMerge(Representative):FirstSurfaceMerge(Representative):FirstSurfaceMerge(Representative):FirstSurfaceMerge(Representative)

FigureFigureFigureFigure26262626:SecondSurf.:SecondSurf.:SecondSurf.:SecondSurf.Merge(Rep.)Merge(Rep.)Merge(Rep.)Merge(Rep.)

FigureFigureFigureFigure27272727FinalToothFormsFinalToothFormsFinalToothFormsFinalToothForms

SURFACE MERGE

ReferringtotheFlatFaceToothExceptionintheSectionDatumPointLayoutsection,themodificationtotheinnermostpoint’sdimension,changetoFW/2 ,mustbeperformedbeforeproceedingforthattypeofgear.

First Feature

SelecttheRTSandone(1)sidesurface(theorderisunimportant).FromthePDM,selectEdit>MergeEdit>MergeEdit>MergeEdit>Merge.Flippingthesidesmaybenecessaryforproperclosure.

SeeFigure25.

Second Feature

Selectthefirstmergefeatureandtheremainingsurfaceandrepeattheprocedureasstatedabove.

SeeFigure26.

Figure27showsthefinalresultsforthelatFacedStraightToothandCupFaced(right-hand)SpiralTooth.

SOLID TOOTH

SelectthesecondmergefeatureandfromthePDMselectEdit>SolidifyEdit>SolidifyEdit>SolidifyEdit>Solidify

ThePinion/Mitertemplateisnowcomplete,sosave.

Gear Template

TomaketheGeartemplateitisbesttousethePiniontemplateasatemplate,doublingtheNUMBER_OF_TEETHparameter.Geometryconstructionfailurewilloccurforthesecondsurfacefeature,andthusthesolidifyfeatureaswell.



14

FigureFigureFigureFigure28282828:GroupFeatures:GroupFeatures:GroupFeatures:GroupFeatures

ChoosetoClipSuppressClipSuppressClipSuppressClipSuppressthefaults.

Redefinethefirstmergeflippingthedirectionsasnecessaryforproperclosure.

Un-suppressthesecondmergefeatureandperformthesameredefinitionroutine.

Finally,un-suppressthesolidifyfeature.

TheGeartemplateisnowcomplete,sosave.

Tip:Tip:Tip:Tip:Todisplayabettermeshrepresentationinuse,modifyeitherthePinionortheGearTCSYSdimensionfromthearbitraryangleuseduponcreationtoeither0°or90/NUMBER_OF_TEETH.Thematinggear’stemplatedimensionisthenadjustedtotheremainingvalue.AnexceptionpertainswhenMiterGearsarecreatedsincebotharederivedfromPiniontemplates.

Using the Templates

Thefollowingnowdescribesthemethodtobuildagearset.

INITIAL MODIFICATION

Afteropeninganewpartwithatemplate,PinionorGear,itisbesttomodifyanyknowntoothgeometrytothemanufacturer’svalues.

Therearefourmainvaluesthatcanbemodifiedtoadjustthetoothform.

• ADDENDUM

• DEDENDUM

• FACE_ANGLE

• ROOT_ANGLE

ThesearethedrivingdimensionsfortheRTS,tomodifythem,openTools>RelationsTools>RelationsTools>RelationsTools>RelationsfromthePDM.Atthebeginningofeachdefinition,place‘/*’(slashstar).Thisactioncommentsoutthatline.

NextopenTools>ParametersTools>ParametersTools>ParametersTools>Parametersandphysicallymodifythevaluestotheknownvaluesandregeneratethemodel.

AnyflatsorroundscanbeaddedbymodifyingtheRTSsketchwiththeappropriategeometry.

Tip:Tip:Tip:Tip:AsketchpointwillneedtobeplacedattheintersectionofthetoenormalCLandthefaceangleCLasadimensionreference.

PINION / MITER

Tooth Group

Toefficientlypatterntheprototooth,allfeaturesfromtheTCSYStotheSolidifyaregrouped.Ensureallbrancheswithinthesefeaturesarecollapsed.SelecttheTCSYSand,withthe‘Shift’keydepressed,selecttheSolidifyfeature.PresstheRightMouseButton(RMB)andselectGroupGroupGroupGroup.

SeeFigure28.

Pattern

SelectthegroupcreatedaboveandRMBandselectPatternPatternPatternPattern.SelecttheTCSYSzrotationalangleasthedrivingdimension.Enteranarbitraryangleandleavethenumberofcopiesatthedefaultvalueoftwo(2).

SeeFigure29.



15

FigureFigureFigureFigure29292929:ToothPatternDimension:ToothPatternDimension:ToothPatternDimension:ToothPatternDimension

FigureFigureFigureFigure30303030:CompletedPattern(Rep.):CompletedPattern(Rep.):CompletedPattern(Rep.):CompletedPattern(Rep.)

RELATIONS

SelectthepatternandRMB.PickEditEditEditEditfromthemenu.SelecttheangledimensionandenterNUMBER_OF_TEETH,agreeingwiththerelationuponexiting.

FromthePDMpickInfo>SwitchInfo>SwitchInfo>SwitchInfo>SwitchDimsDimsDimsDims.Notethe

dimensionforthenumberofcopiesinthepattern,P## .

OpentheTools>RelationsTools>RelationsTools>RelationsTools>RelationsfromthePDM.Scrolltothebottomandentertherelation:P##=NUMBER_OF_TEETH.Thisdimensionaltypecannotbedirectlymodifiedintoarelation.

SeeFigure30.

Note:Note:Note:Note:Awarningwilldisplayinformingofdisconnectioninallcopiesofthetooth.Afterthecoreisbuilt

connectionwilloccur.Core

Forclarityofworkspace,itwouldbebeneficialtomodifythedisplayto“WireFrame”mode.

ThecoreisaRevolvedSolidFeatureRevolvedSolidFeatureRevolvedSolidFeatureRevolvedSolidFeaturerotatedthrough360°.

Note:Note:Note:Note:Therearemanyvarietiesofgearblanks.Forthesakeofsimplicity,onlythebasicmiterstyleinstructionsaregiven.Othergeneraltypesareintheexamplefilesforreference.

SKETCH PLANE

ThesketchplaneistheRight(PYZPLN)withtheTop(PXZPLN)asthetopreference.

REFERENCE GEOMETRY

SelectthePartCoordinateSystem(PCSYS)asthereference.

SKETCH, CONSTRUCTION GEOMETRY

ThecoresketchbeginsasacombinationoftheSPDandRTSsketches.AhorizontalCLisplacedthroughthePCSYSreference.Asecond,angledCLisplacedthroughtheTCSYSfromthelowerlefttotheupperright,thePL.ModifytheweakdimensiontobeequaltothePCA.

PlaceasketchpointontheupperportionofthePL,theHeelPitchPoint(HPP).ModifytheWeakDimensiontoberelatedtoPITCH_DIAMETER/2.

PlaceanotherpointonthePLbetweentheHPPandthePCSYS,theToePitchPoint(TPP).ThisistobedimensionedfromheelpointalignedwiththePL.ThedimensionvalueisequaltotheFACE_WIDTH(FW).

AddadditionalCLsthrougheachPPthatarenormaltothePL.

OnthenormallinethroughtheHPP,placeoneSketchPointbelowthePL.DimensionthepointfromthePLequaltotheDEDENDUM.

Throughthepoint,makeaCLatananglewithnootherconstraints.Theweakdimensionsshould

beangularfromthehorizontalCL.Modifythepoint’sdimensiontobeequaltotheROOT_ANGLE.



16

FigureFigureFigureFigure32323232:GapFiller:GapFiller:GapFiller:GapFiller

FigureFigureFigureFigure31313131::::PCSYSReferencePCSYSReferencePCSYSReferencePCSYSReference

FLAT FACE GEARS

AddanadditionalpointabovetheHPP.TheupperdimensionisequaltotheADDENDUM.Throughthepoint,makeaCLatananglewithnootherconstraints.TheweakdimensionsshouldbeangularfromthehorizontalCL.Modifythepoint’sdimensiontobeequaltotheFACE_ANGLE.

PlaceaVerticalCLthroughtheintersectionthefaceangleandToenormalCL.

SKETCH, FEATURE GEOMETRY

DrawahorizontallinebetweentheTPPpasttheHPP,thenaverticallineuptoaboutmidwaytotheHPP.Next,drawanotherhorizontallinetowards,butnotto,theHPPNormalCL.

Note:Note:Note:Note:ForFlatFaceGears,ignorethenextinstruction.

Modifythefirstline’sweakdimensiontobeequaltotheBORE_LENGTH.

Modifythelastline’sweakdimension(itshouldbethelengthfromthesecondline)tobeequaltotheHUB_LENGTH.

AddahorizontaldimensionfromthePCSYSreferencetothevertical(second)line.ThisisequaltotheMOUNTING_DISTANCE.Besurethatthecoordinatereferencepointisselected.SeeFigure31.

AddadiametricaldimensionbetweentheBoreLengthlineandtheHorizontalCL.ThisisequaltotheBORE_DIAMETER.

AddadiametricaldimensionbetweentheHubLengthlineandtheHorizontalCL.ThisisequaltotheHUB_DIAMETER.

DrawalinefromtheappropriateToeDedendumPoint,forthetypebeingconstructed,totheHeel

DedendumPoint.Then,drawalinealongtheHPPnormalCLsothattheendpointisconstrainedcollinearlytotheHubLengthline.Fillanygap,ifoneexists,betweentheendpointsofthetwolines.

SeeFigure32.

CUP FACE GEARS

DrawalinealongtheTPPnormalCLtowardsthehorizontalCL,butnottoit.DrawaverticallinefromthefreeendpointoftheBoreLengthlineuptowardsthepreviousline.Trimtointersect.

SeeFigure33.

FLAT FACE GEARS

DrawalinefromtheDedendumCLandVerticalCLintersection,atthetoeend,verticallydownwardstowardstheBoreLengthline.Trimtointersect.

Thesketchisnowcomplete.Saveandclosethesketchandfeature.SeeFigure34.



17

FigureFigureFigureFigure33333333:CoreSketch&Relations:CoreSketch&Relations:CoreSketch&Relations:CoreSketch&Relations

FigureFigureFigureFigure34343434:Pinion:Pinion:Pinion:Pinion

FigureFigureFigureFigure35353535:PatternedGearToothPart:PatternedGearToothPart:PatternedGearToothPart:PatternedGearToothPart

GEAR

Gear Tooth

Usetheappropriatetoothtemplateandmodifytheparametersforthetooth.

Note:Note:Note:Note:Theauthorusesthenamingstructure:PART-NAME_T.PRTforthetooth.Thegearassemblyisnamed:PART-NAME_PRT.PRT.ThegearcoreisnamedPART-NAME.PRT,sincethiswillbethepartusedwithitsmate.

Gear Part Assembly

Theonlyaddition,besidestheNUMBER_OF_TEETHparameter,toabasicassemblyfileistheadditionofadatumaxisusedtoalignthetoothpart.

UsetheassemblytemplateandmodifytheNUMBER_OF_TEETHparameter.Assemblethetooth(PART-NAME_T.PRT)usingthePCSorRTSaxisasanAlignoptiontotheGEAR_AXISaxis.

UsethePXZPLNorPYZPLNtomateusingtheanglealigntypeofconstrainttotherespectiveassemblyplane.AssemblethePXYPLNtothePAXYPLNwithazero(0)offset.

Patternthetooth,RMB>PatternRMB>PatternRMB>PatternRMB>Pattern,andusethezero(0)dimensiontodrivethepattern.Theincrementis360/NUMBER_OF_TEETH,agreeingtotherelation.Leavethenumberofcopiesasthedefaultvalue(2).

UnderTools>RelationsTools>RelationsTools>RelationsTools>Relations,enterDy=NUMBER_OF_TEETH,whereDyisthedimensionforthenumberofcopies(Info>SwitchDimsInfo>SwitchDimsInfo>SwitchDimsInfo>SwitchDimstoverifythedimensionnumberbeforehand).

SeeFigure35.

Gear Core

DrawthecoreinasimilarmannerasthatoutlinedinthePinion/MiterCoresectionabove,modifyingtheproceduretosuitthetype.

SeeFigure36.

Insertintothegearpartassemblyusingacoordinatesystemmate.SeeFigure37.



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FigureFigureFigureFigure36363636:GearCoreSketch&Relations:GearCoreSketch&Relations:GearCoreSketch&Relations:GearCoreSketch&Relations

FigureFigureFigureFigure37373737:GearPartAssembly:GearPartAssembly:GearPartAssembly:GearPartAssemblyMerge

Nowthepatternedteethareaddedtothecore.

UnderEdit>ComponentOperations>MergeEdit>ComponentOperations>MergeEdit>ComponentOperations>MergeEdit>ComponentOperations>Merge,SelectthecorepartandclickOKOKOKOK.

IntheModelTree,expandthetoothpatternsothatallinstancesaredisplayed.

Selectfirstinstance,andwiththeShift keyhelddown,selectthelastinstanceandclickOKOKOKOK.

Fortheoptions,selectReferenceReferenceReferenceReference,OKOKOKOK,andNoDatumsNoDatumsNoDatumsNoDatums.

SelectDoneDoneDoneDoneonetimeforeveryinstance!

ThenselectDone/ReturnDone/ReturnDone/ReturnDone/Returnafterthelasttoothhasbeenadded.

Mating Pairs

ASSEMBLY SETUP

Therearetwomethodsinwhichthegearpairisusedinanoverallassembly.

Existing Shafts

Thisisthemostlikelymethodtobeemployed.

Usetheboreandtheappropriateshaftsegmentasmatingreferences.Matethemountingsurfacetotheshaft.Mateoneofthepartplanesperpendiculartothegearaxistoasimilarshaftplane.

Tip:Tip:Tip:Tip:Useanangulartypeonthelastconstraintsothatanangleisathandtoallowrotationaladjustment,ifrequired(seebelow).

First Parts

Twoaxesarerequiredwiththemutualincludedshaftanglebetweenthem.Alsorequiredaretwoplanes(orsurfaces),eachnormaltotherespectiveaxisforthegear.Theplanescanbeateitherthecommonvertexortheactualmatingdistanceforthegear.Itwouldbebeneficial,forrotationalalignment,tohaveacommonassemblylevelplanethroughbothaxes.

Theauthor,intestcases,usedplanesatthecommonvertex.

MATING CONSTRAINTS

Eachgearisassembledwitha“PinConnection”constraint.ThisallowsfortheapplicationofBehavioralModeling.

Thepredefinedassemblyaxisisconstrainedtothe‘core’featureaxisofthegearfortheAxisalignment.

ThePXYPLNortheactualmountingsurfaceisthepartreferencewhiletheprescribedmatingsurfacesaretheassemblyreferencefortheTranslation.

TheRotationAxisreferencewouldbethecommonplanethroughbothaxesasmentionedabove.

Setthezeropositionforbothgearsinthesetsothatthepairappearsinmesh.

Remembertocheckthe“Enableregenerationvalue”toregainmeshappearance.



FigureFigureFigureFigure38383838:AssemblyAngleModification:AssemblyAngleModification:AssemblyAngleModification:AssemblyAngleModification

FigureFigureFigureFigure39393939:Crowning:Crowning:Crowning:CrowningModificationModificationModificationModification

ANGLE MODIFICATION

Onoccasion,todisplaythegearpairinpropermesh,itwillbecomenecessarytomodifythevaluefortheRotationAxistosomevalueotherthanzero(0).Intestcases,thevaluewas5°.Remembertoresettheregenvalue(makezero).SeeFigure38.

Modifying Gears

ZEROL BEVEL GEARS

BysettingtheSpiralAngletozero(0),thegearwillgeneratewith“Zerol”styleteeth.

CROWNING

Bymodifyingtherotationalangleamount,viapercentages,ToothCrowningcanbesimulated.SeeFigure39.

Documents

Bevel Gears in ProE