Foire aux Questions sur les Machines d’équilibrage dynamiques et Answers(B)



Q.Whyismeasuringofbalancingspeedofthecomponentvery

importantinabalancingmachine ?

A.Balancingmachineisanindustrialmachine.Themachineis

locatedinafactoryenvironmentalongtheprocessline. Manytypes

ofindustrialnoiseselectrical, mécanique, magneticwillexistinan

industrialenvironment. Besidesthisbalancingmachinehasdrive

elementslikemotors, poulies, beltswhichalsorotatealongwiththe

composant "". Thecomponentismountedonrollers, androllersalso

rotatealongwiththecomponent. Thetransducerswillpickup

signalsfromallrotatingelements. Theelectronicsofthebalancing

machineneedsareferencesignaltoextracttheunbalancesignalof

thecomponentbeingbalanced. Thespeedsignalofthecomponent

beingbalancedprovidesthereferenceforsignalextraction.

Inolderstroboscopemachines, itcanbeobservedthatthe

unbalancelocationwillstartshifting/oscillatingoverawideangle

whenbalancingisdone. Inmodernmachineswithphaselockloop,

theshiftofangleisreducedtoinsignificantlevels.

Q.Whydoweneedmultispeedbalancingmachines ?

A.Multispeedbalancingmachinesarenormallybigsizemachines

andmachineswhichhandlearangeofjobs. Incasethecomponent

isamassproducedcomponentwithpredictablelevelsof

balourd, singlespeedmachinescanbetunedtobalancethe

componentsfasterandwellwithinthetolerance. Butinheavy

composants, thelevelofunbalancemaynotbeknowninitially. Il

maybehazardousfromthepointofsafetytodirectlyrunthe

componentattherequiredbalancingspeed. Oui, heavycomponents

arerunatlowerspeeds, initialbalancingisdone. Furtherbalancing

isdoneathigherspeedstillthedesiredlevelofaccuracyis

Atteint.



Q.DoweneedtoputDynamicBalancingMachinesonafoundation ?

A.Balancingmachineisanindustrialmachineusedtomeasure

Vibrationandcomputetheresidualunbalance.ModernHardBearing

BalancingMachinesareforcemeasuring.ItisessentialthattheMachine

donotvibrateorshakeforcorrectmeasurementofunbalanceamountand

phaseAngle.

Formorepreciseresultsitisrequiredtomountthemachinesfirmlyonanindustrialfloor.




Q.Whatisunbalancereductionratio ?

A.Balancingmachineinstrumentationindicatesthelevelofunbalanceon

thecomponentbeingbalanced. Agoodmachinecanindicateavalueand

whenacorrectionequivalenttothevalueshownisexecutedthenextresultantresidual

unbalanceshouldbebelow90 - 95 % ofthefirstindicatedvalue.

Parexemple, onthefirstrun, ifthemachinehasshownsay50gramatagivenlocation.

Whena50gramweightisaddedatthatlocationandaresidualunbalancereadingtaken,

incasethemachineindicatesavalueof5gramandbelow, thenitissaidthatthemachine

ishavinganunbalancereductionratioofabout90 %.

FormoredetailsrefertotheISOstandards1940, 2953etc.




Q.Whatisplaneseparation,crosseffect,influence ?

A.Intwoplanedynamicbalancingmachines,theresultsareindicatedintwo

correctionplanes. Whenacorrectionismadeononeplane, theeffectofthe

unbalancecompensationonthesecondplane, isdefinedasplaneseparation

orcrosseffectorinfluence. Normalement, theplaneseparationwillbewellbelow3 %.

Incomputerbasedhardbearingdynamicbalancingmachines, theplane

separationisachievedmathematically. Souserstendtogetbetter

levelsofplaneseparationoncomputerizedhardbearingdynamic

balancingmachinesandthatisnotthecasewithsoftbearing

machineswhereinunbalancesignalsareelectronicallymixedand

modulatedforindicatingtheresults.