Rim-Face

7/30/2019 Rim-Face

1/23

4-1

Section4

Sec

tion

4

Rim

&Face

Alignment

Me

tho

d

Sec

tion

4:

Rim-Face

Alignmen

tMe

tho

d.......

4-2

MountingtheDialIndica

torFixtures.................4-3

MeasuringtheA,B,&C

Dimensions...............4-5

ObtainingAs-FoundReadings.........................4-6

Measuring&Interpreting

Vertical

Misalignment................

...................................4-7

Measuring&Interpreting

Horizontal

Misalignment................

...................................4-9

CalculatingtheFrontan

dRearFeetPositions4-11

Rim-FaceCalculationPrecautions.................4-12

ConstructingaRim-FaceGraph....................4-13

PlottingOffsets.............

.................................4-16

DeterminingtheMovableShaftPosition........4-18

Rim-FaceGraphingPrecautions....................4-20

MakingVerticalCorrections...........................4-22

MakingHorizontalCorre

ctions.......................4-23

7/30/2019 Rim-Face

2/23

4-2

Sec

tion

4:

Rim

&Face

Alignmen

tMe

tho

d

YoucanusetheRim&Fa

ceMethodtoperforma

calculatedprecisionalignm

entprocess.

Youmayuseavarietyofs

haftalignmentfixtures.We

recommendthatyouusea

commercialpackage

designedtoaccommodate

avarietyofshaftdiameters.

Thefixturesshouldinclude

anassortmentofrodsto

spanvariouscouplingleng

ths.Thesepackages

expeditetheprecisionalignmentprocess.Also,sag

valuescanbepre-determinedforthestandardrod

assortment.

ToperformtheRim&FaceMethod,youmust:

Mountthedialindicatorsfixtures.

MeasuretheA,B,&C

dimensions.

Obtainas-foundreadings.

Determinetheverticalfootpositions.

Makeverticalcorrectio

ns.

Makehorizontalcorrections.

Re-measureandrecordfinalalignmentvalues.

7/30/2019 Rim-Face

3/23

4-3

Section4

Moun

ting

the

dialindica

tor

fix

tures

Tomountthefixturesfollowthesesteps:

1.

Withthecouplingbroken,mountthefixturetothe

stationaryshaftorcou

plinghub.

2.

Spanthecouplingwitharod.

3.

Rotatethefixtureto12:00.

4.

Attachthefacedialindicator.Thedialindicator

plungermustbecente

redforequalpositiveand

negativetravel.

5.

Attachtherimdialind

icator.Thedialindicator

plungermustbecente

redforequalpositiveand

negativetravel.

7/30/2019 Rim-Face

4/23

4-4

Fixture

Moun

ting

Prec

au

tions

Regardlessofthespecific

hardwarebeingused,the

followingprecautionsshou

ldbeobserved.

Neverattachthefixtur

etotheflexibleportionofthe

coupling.

Maximizethesweepd

istanceofthefacedial

indicatorforthegeom

etryofthemachinebeing

aligned.Ifthefacedialcontactsthecouplingface

directly,ensuretheplungerofindicatorcontacts

thecouplingnearitso

uteredge.

Ensurefixturesaremountedatapositionwhere

rotationispossible.Itisdesirabletohave360

degreesofrotation.

Beforeobtainingalignmentmeasurements,determine

dialindicatorbarsagoftherimdialindicatorand

ensuredialindicatorreadingsarevalidandrepeatable.

SeeSection2fordetails.

7/30/2019 Rim-Face

5/23

4-5

Section4

Measuring

the

A,

B,

&

Cdimens

ions

TomeasuretheA,B,&C

Dimensions,followthese

steps.

1.

The

ADimens

ionisthediameterofface

indicatortravel.The

ADimensionshouldbe

slightlylessthanthec

ouplingdiameter.

Thisisthemostcriticaldime

nsion.

MeasureAverycarefully.

2.

The

BDimens

ionisthedistancefromtherim

indicatortothefrontfootboltcenter.This

dimensionismeasure

dparalleltotheshaft.

3.

The

CDimens

ionisthedistancebetweenfront

andrearfootboltcenters.Thisdimensionis

measuredparalleltotheshaft.

7/30/2019 Rim-Face

6/23

4-6

Obtaining

As-foun

dRea

dings

Toobtainacompleteseto

fas-foundreadings,perform

thestepsbelow:

1.

Rotatethedialindicatorsto12:00.

2.

Settherimdialindicatortothepositivesagvalue.

3.

Setthefacedialindicatortozero.

4.

Recordthesettingofbothdialsat12:00.

5.


6.

Determineandrecord

thereadingonbothdials.

7.


8.

Determineandrecord


9.


10.Determineandrecord


11.Rotatethedialsto12:00andensurebothdials

returntotheiroriginal

setting.

Documentas-foundresultsusingaformatsimilarto

thatshownbelow.

7/30/2019 Rim-Face

7/23

4-7

Section4

Measuring

&Interpret

ing

Vert

ica

l

Misa

lignmen

t

Tomeasureverticalmisalignment,performthe

followingsteps:

1.


2.

Setthefacedialindicatortoreadzero.

3.

Settherimdialindicatortothesagvalue.

4.

Rotatebothshafts(ifpossible)to12:00.

5.

RecordtheDIRandD

IFdialindicatorTIRvalues.

7/30/2019 Rim-Face

8/23

4-8

Todetermineoffsetandan

gularityfromthe12:00

TIRs,usethefollowingrules:

CouplingOffset=Rim

Dial(DIR)TIR

2

ShaftAngularity=Fac

eDial(DIF)TIR

A

dimension

7/30/2019 Rim-Face

9/23

4-9

Section4

Measuring

&Interpret

ing

Horizon

tal

Misa

lignmen

t

Tomeasurehorizontalmisalignment,performthe

followingsteps:

1.


2.

Setbothdialindicatorstozero.

3.

Rotatebothshaftsto3:00.

4.

RecordtheDIFandDIRdialindicatorTIRvalues.

7/30/2019 Rim-Face

10/23

4-10

Todetermineoffsetandan

gularityfromthe3:00TIRs,

usethefollowingrules:

CouplingOffset=Rim

Dial(DIR)TIR

2

ShaftAngularity=Fac

eDial(DIF)TIR

Adimension

7/30/2019 Rim-Face

11/23

4-11

Section4

Ca

lcu

lating

the

fron

ta

ndrear

fee

tpos

itions

Fron

tfoo

tpos

itionc

alcu

lation:

Rear

Foo

tpos

itionc

alcu

lation:

Positivevaluesmean

thefootishigh,shimsmust

beremoved.

Negativevaluesmean

thefootislow,shimsmust

beadded.

7/30/2019 Rim-Face

12/23

4-12

Rim-Face

Ca

lcu

lation

Precau

tions

1.

EnsuretherimandfacedialindicatorTIRsare

properlydeterminedfr

omthedialspriorto

performingcalculation

s.

2.

BecarefulNOTtomakemathematicalerrorswhen

subtractingsignednumbers.

3.

Observeparentheses

intheequations.Perform

operationsinsidepare

nthesisfirst.

4.

DoNOTmakehuman

errorssubstitutingreal

valuesintotheequatio

ns.

5.

EnsuretheA,B,andCdimensionsareaccurate

andareproperlyenter

edintotheequations.

7/30/2019 Rim-Face

13/23

4-13

Section4

Cons

truc

ting

ARim-Face

Grap

h

ToconstructascaledRim-Facegraph,performthe

followingsteps:

1.

Obtaingraphpaperwith10divisionsbetweenbold

lines.

2.

Turnthegraphpapersothatthelongsideis

horizontal.

3.

Drawahorizontalline

atthecenterofthepage.

Thislinerepresen

tsthestationaryshaftcenter

andisdrawnacro

ssthepagemidwaydown

thegraphdividing

thepage.Itishelpfulifthis

lineisontopofoneoftheboldlines.

4.

Determinethehorizon

talplottingscale.

Alwaysusethela

rgestscalepossible.

Measurethedista

ncefromthestationary

indicatorplungertothecenter-lineoftherear

feetofthemovablemachine.Standardgraph

paperisabout10

inchesacross.Thelargest

horizontalscalew

illbethemachinedistance

dividedbythepagewidth.Noteyour

horizontalscale.

5.

Makeaverticallineon

theextremeleftofthe

horizontalline.

7/30/2019 Rim-Face

14/23

4-14

Thismarkrepresentsthepointwheretherim

dialindicatorcontactstheshaftorcoupling

hubandislabeled:DIR.

6.

Makeasecondverticallinerepresentingthe

pointalongthesh

aftlengthofthefrontfeetof

themovablemachine(FF).

7.

Makethethirdverticallinerepresentingthe

pointalongthesh

aftlengthoftherearfeetof

themovablemachine(RF).

7/30/2019 Rim-Face

15/23

4-15

Section4

Uponcompletionoftheste

psabove,thegraphwilllook

similartotheoneshownbelow.Forthisexample,the

BandCdimensionsbothequal10inches.

7/30/2019 Rim-Face

16/23

4-16

Plotting

Offse

ts

Aftersettingupthegraph,

thenextstepistoplottwo

offsetpoints.Oneistheo

ffsetmeasuredintheplane

oftherimdialindicator(DIR).Theotheroffsetpointis

derivedfromthefacedialindicator(DIF)readingand

theAdimension.Toplottheoffsets,performthe

followingsteps:

1.

Determinetheverticalscale.

Theverticalscale

istypically1mil(0.000)per

division.Incases

ofgrossmisalignment

wheretheoffsets

willnotfitonthepage,a

largerscale,such

as2-3milsperdivision,is

sometimesrequired.

2.

PlottheoffsetfromtherimdialindicatoronlineDIR.

Usethehorizonta

llinerepresentingthe

stationaryshaftcenterlineasthereference.All

pointsabovethis

horizontallinearepositive(+)

andallpointsbelowthelinearenegative(-).

Ensureyoudivide

theRimDialTIRby2to

obtainanoffsetvalue.

3.

Plotthesecondoffset

pointusingtheshaftslope

(FaceTIR/Adimension).

Plotthispointcou

ntingfromtheDIRoffset

point!

7/30/2019 Rim-Face

17/23

4-17

Section4

Intherim-facegraphexam

plebelow,theDIRoffsetis-

10milsandtheshaftslopeis+4milsoveranA

dimensionof5.

7/30/2019 Rim-Face

18/23

4-18

De

term

ining

Mova

bleSha

ftPos

ition

Afterplottingthetwopoints,todeterminethemovable

shaftpositionperformthefollowingsteps:

1.

Usingarulerorstraightedge,drawaline

throughthetwoo

ffsetpointsthatextendsto

therearfeetofthemovablemachine.

2.

Countthenumberofsquaresintheplaneof

thefrontandrear

feettodeterminethe

positionandcorre

ctionsneeded.

7/30/2019 Rim-Face

19/23

4-19

Section4

Intheexamplebelow,thefrontfeetofthemachineare

2milslow;shimsneedtobeadded.Therearfeetare

positioned6milstoohigh;

shimsneedtoberemoved

frombothrearfeet.

7/30/2019 Rim-Face

20/23

4-20

Rim-Face

Grap

hing

Pr

ecau

tions

1.

Ensureproperhorizon

talandverticalscaling

techniquesareconsistentlyused.

2.

Alwaysdoublecheckthepositionofverticallines

drawntorepresentthe

DIR,FF,andRF.

3.

Ensurethetwoplotpo

intsareproperlydetermined

fromTIRs.

4.

Ensurepositiveoffsetsareplottedabovethe

horizontalreferencelineandnegativeoffsetsare

plottedbelowtheline.

5.

Wheninterpretingthe

graphtodeterminethe

movableshaftsfrontandrearfeetpositionsinthe

verticalplane,observe

thefollowingrules:

Ifthemovableshaftisabovethehorizontal

stationaryshaftre

ferencelinetheshaftistoo

high.

Ifthemovableshaftisbelowthehorizontal

stationaryshaftre

ferenceline,theshaftistoo

low.

7/30/2019 Rim-Face

21/23

4-21

Section4

6.

Wheninterpretingthe

graphtodeterminethe

movableshaftsfrontandrearfeetpositionsinthe

horizontalplane,view

thegraphthewayyouview

themachine,thatis,s

tandingbehindthemovable

machinefacingthestationarymachine.Also

observethefollowingrules:

Ifthemovableshaftisabovethehorizontal

stationaryshaftre

ferencelinetheshaftis

positionedtotheright.

Ifthemovableshaftisbelowthehorizontal

stationaryshaftre

ferenceline,theshaftis

positionedtotheleft.

7/30/2019 Rim-Face

22/23

4-22

Ma

kingvert

ica

lcorrec

tions

Tocorrectverticalmisalignment,followthesteps

below:

1.

Determinetheverticalpositionofthemovable

machineusingcalcula

tionand/orgraphing

techniques.

Positivevaluesatthefeetmeanthatthe

movablemachine

ishigh,thereforeyouwill

removeshims.

Negativevaluesm

eanthatthemovablemachine

islow,soyouwilladdshims.

2.

Makeshimchangesto

bothfrontfeetandboth

rearfeetasneeded.

3.

Alwayscheckshimthicknesswithanoutside

micrometer.Precutshimsaren'talwayswhat

they'remarked;many

shimmanufacturers

designateshimswiththenominalthickness.

4.

Useconsistentandco

rrecttorquingprocedures.

5.

Asshimchangesaremade,checkforandtake

precautionstoavoidc

reatingsoftfootconditions.

7/30/2019 Rim-Face

23/23

4-23

Section4

Ma

king

horizon

talcorrec

tions

Tocorrecthorizontalmisalignment,followthesteps

below:

1.

Rotatethedialindicatorsto9:00andzerothem.

2.

Rotatebothshafts(ifpossible)to3:00.

3.

Adjustthedialindicatorstoone-halfvalues.

4.

Movethefrontfeetof

themovablemachineasyou

watchtherimindicato

rmovetozero.

5.

Movetherearfeetoft

hemovablemachineasyou

watchthefaceindicatormovetozero.

6.

Repeatsteps4&5un

tilbothdialindicatorsread

zero.

Documents

Rim-Face