formulaqq空间电脑版特别关心
qq空间电脑版特别关心 时间:2021-04-20 阅读:()
TemperatureFieldAnalysisandExperimentalTestofCNCLathePrecisionSpindleSystemwithoutLoadLixiuZhang1,a,QinghuaShi2,bandYuhouWu3,cShenyangJianzhuUniversity,Shenyang110168,Chinaa851617088@qq.
com,b474891749@qq.
comKeywords:mechanicalspindle;thermalanalysis;temperaturefield;thermalbalancetime.
Abstract:ThearticleisbasedonprecisionCNClathespindlesystemofthe170CP06astheresearchobject.
Thesteadyandtransienttemperaturefieldmodelofthemechanicalspindleisestablishedbyusingthefiniteelementanalysismethod.
Astheheatratefortheloadandtheconvectiveheattransfercoefficientfortheboundaryconditionsforthermalanalysis,thetemperaturefieldofspindlesystemisinvestigatedtogetthesteadystatetemperaturefielddistributionandthermalbalancetimeofthespindlesystem.
Inordertoverifythecorrectnessofthemodel,thethermalexperimentswithoutloadareexecutedtothekeypartsofthetemperatureofthespindlesystematdifferentspeeds.
Comparedwiththesimulationresults,ithasaverygoodagreementwiththereliabilityofthemodel.
Anditprovidesatheoreticalbasisforcontrollingthetemperatureriseofthespindlesystem.
IntroductionWiththerapiddevelopmentofmodernmachinerymanufacturingtechnology,therequirementsofmachine'saccuracyarealsobecominghigherandhigher.
Inthehigh-speedandprecisionmachinetools,theproblemofmachiningerrorcausedbythermaldeformationalsohasbecomeincreasinglyserious.
Alargenumberofexperimentalstudiesshowthethermalerroristhelargesterrorsourceofmachinetoolsaccountingfor40%to70%inthetotalerrorofthemachine[1].
Thespindleisoneoftheimportantcomponentsofthemachine,anditsperformanceaffectstheoveralllevelofthemachinedirectly.
Whenthemechanicalspindleisworking,theinternalheatsourceofthespindlecomesformtheheatgeneratedbythefrictionofhigh-speedrotation'sbearing.
Whenthetemperaturehasrisen,therelativespatialpositionandsizeofthespindleandotherpartsofthemachinewillbedifferentfromtheprevioustemperature.
Itwillformadifferenttemperaturefieldandproducedifferentdegreesofthermaldeformation[2].
Therefore,thethermalcharacteristicsofresearchandanalysisonthespindlesystemiscrucialtoensuretheaccuracyofthemachine.
Itisoneofthekeytechnologiestobeconsideredinhighprecisionmachinetools.
Thethermalcharacteristicsanalysisofthespindlesystemistostudythedistributionofthetemperaturefield.
Atpresent,therearemanyscholarswhostudythethermalcharacteristicsofmachinetoolspindlesystemathomeandabroad.
Forexample,JinKyungChoiofSouthKoreastudiedthermalcharacteristicsforthespindleandbearingsystemwiththefiniteelementmethod[3].
M.
H.
AttiafromCanadaanalyzedthewholetemperaturefieldofthemachineusingthefiniteelementmethod[4].
CeGuoandQinghongSunfromSoutheastUniversityhavealreadyestablishedafiniteelementmodelofthehigh-speedprecisionlathespindlecomponents'temperaturefield[5].
YouweiHongestablishedthefiniteelementmodelofthegantrymachiningcenterandsimulatedthetemperaturefielddistributionandvariation[6].
ThearticleisbasedonCNClatheprecisionspindlesystemofthe170CP06astheresearchobject.
Thetemperaturefieldmodelofthemechanicalspindleisestablishedanditisconductedthesteady-stateandtransientthermalanalysisofthespindlesystem.
Thetemperaturefieldofspindlesystemisinvestigatedtogetthetemperaturefielddistributionandthermalbalancetimeofthespindlesystem.
Thethermalexperimentswithoutloadarecarriedoutinordertoverifythereliabilityofthemodel.
CalculationofthethermalparametersTheheatsourceisthefoundationofthespindletemperaturefieldresearch.
Theheatsourceofthespindlesystemincludescuttingheatandbearingfrictionheat.
Thecuttingheatinthemachiningprocessistakenawaybycoolantliquidandswarf.
Therefore,theheatsourceofthespindlemaybemainlythebearingfrictionalheat.
CalculationofthecalorificvalueTherollingbearing'sheatismainlygeneratedbythebearingfrictionaltorque.
Theformulais41.
04710fHnM=*(1)Intheformula,Hfisthecalorificvalueofthebearing;nisthespindlespeed;M0isthebearingfrictionaltorque.
Thebearingfrictionaltorqueisthesumofthebearingrollingfriction,slidingfrictionandlubricantfrictionwhichhavegeneratedtoblockthebearingrunningtorque.
Palmgren[7]deducedtheempiricalformulawhichcalculatesthebearingfrictiontorque.
Thebearingfrictionaltorqueiscalculatedas01MMM=+(2)Intheformula,M0isrelatedtotheviscosityofthelubricant.
M1isrelatedtotheloadofthebearingregardlessofspeed.
ItonlyconsidersM0withoutload.
Palmgrenconfirmedtheexpressionusingempiricalmethods:72/3300=10()mMfnDν2000nν≥(3)730016010mMfD=*2000nν<(4)Intheformula,νisthekinematicviscosityofthelubricantinthebearingoperatingtemperature,mm2/s;0fisthecoefficientrelatedtothebearingtypesandlubrication,mDistheaveragediameterofthebearing,mm,0.
5()mDDd=+.
Whenthespindlesystemisanalyzed,thethermalloadisloadedbythewayofbearingtheheatrate.
Theformulais[9]3(/)fHqWmV=(5)Intheformula,Visthevolumeoftheheatsource;22)2/(bmDDVπ=,andDbisthediameteroftherollingelements.
Calculatedbytheequation(1)to(5),whenthespindlespeedis2000r/min,wecangettheheatratesoftheforeandrearbearingtobe342704.
4W/m3and348161.
76W/m3.
CalculationoftheheattransfercoefficientAccordingtotheheattransfertheory[10],wecanknowtheheattransferwayaretheheatconduction,theconvectionandthethermalradiation,thelossoftheradiationheatislessforthespindlesystem.
Whenweareanalyzingthetemperaturefieldofthespindlesystemonlytoconsiderthethermalconductionandtheconvectionheattransfer.
Thethermalconductivitydependsonthethermalconductivityofthecomponentsinthespindlesystem.
Theconvectiveheattransferistheconvectionofthespindlesurfaceandtheair.
Theconvectiveheattransferisformedbydrivingtherotationofthespindlearoundtheairbetweenthecaseandthespindle.
ThecoefficientoftheheattransferdependsonthecriterionofNusselt[12].
/cchNlλ=(6)Intheformula,chisthecoefficientoftheheattransfer;λisthethermalconductivityoftheair;NisthecoefficientofNusselt;clisthefeaturesize.
TheNusseltformulaoftheforcedconvectionis23130.
133RePrN=5Re4.
3100.
7Pr670)<*<<(,(7)AccordingtoReynoldsCriterion,wecanknowRe=/cculν(8)Intheformula,ReistheReynoldsnumber;PristhePrandtlnumberofthefluid;cuistheaveragevelocityoftheair;νisthecoefficientoftheair'smotionviscosity.
Whenthespindlerotatesbyhighspeed,theaveragevelocityoftheairis[13]=/60cudnπ(9)1122=nndldldldl++(10)12nllll11)Intheformula,distheaveragediameterofthespindle;nisthespeedofthespindle.
Calculatedbytheequation(6)to(11),whenthespindlespeedis2000r/min,wegeteachheattransfercoefficientswhichare26.
62/()Wmk,35.
632/()Wmk,38.
32/()Wmk,32.
52/()Wmk,35.
22/()Wmk.
FiniteelementmodelofthespindlesystemTheprecisionspindlesystemofthe170CP06ismainlycomposedofthespindle,case,beltpulley,bearingcoverandtheangularcontactballbearings,etc.
Themotordrivesbyabeltpulleymountedontheshafttoprovideadrivingforceforthespindle.
Themainparametersofthespindleis:ItsmaterialisalloySteel.
Thetotallengthis497mm.
Themaximumdiameterofthespindleismm100φ.
Theratedspeedofthespindlesystemis4500r/min.
Themaximumpoweris35kWandthemaximumtorqueis180N.
m.
Fig.
1isthestructurediagramforspindlesystem.
1—Bignut2—Beltpulley3—Leftcover4—Case5—Rightcover6—Spindle7—Forebearing8—RearbearingFig.
1StructurediagramforspindlesystemThemodelofthespindlesystemisestablishedbyusingthethree-dimensionalmappingsoftware—SoildWorks.
Anditsimplifiesappropriatelythestructurethatinfluencesanalysisresultsless.
Accordingtothespindleoftheboundaryconditionsandheattransfercharacteristics,Simplifiedsolidmodelisintroducedtothefiniteelementanalysissoftwaretobemeshingofthegrid[12].
Fig.
2isasimplifiedandmeshingmodelofthespindlesystem.
Theentiremodelhas128,143unitsand232,855nodes.
Fig.
2MeshingofthespindlesystemSimulationanalysisofthespindlesystem'stemperaturefieldThethermalanalysisisestablishedinthesoftwareoffiniteelementanalysis.
Thematerialofthespindleandbearingaredefinedasalloysteel.
Theambienttemperatureis26C°.
Accordingtotheboundaryconditionsofthespindleandthecharacteristicsoftheheattransfer,theheatgenerationrateoftheforeandrearbearingsis342704.
4W/m3and348161.
76W/m3whichareappliedtotheforeandrearbearings.
Thecoefficientsoftheheattransferconvectionareaddedtotherespectivemembersurfacespindlesystemasboundaryconditions.
Itisconductedthesteady-stateandtransientthermalanalysisofthespindlesystem.
TheanalysisofthesteadytemperaturefieldWhenthespindlespeedis2000r/min,wecangetthesimulationofthesteady-statetemperaturefieldresultinginthesteady-statetemperaturefieldcontourofthespindlesystem.
AsisshowninFig.
3.
Fig.
3Steady-statetemperaturedistributionofspindlesystemFig.
3showsthatthemaximumtemperatureofthespindlesystemappearsattheinnerringoftherearbearing.
Itstemperatureis38.
5C°.
Themaximumtemperatureriseis12.
5C°.
Theheatoftherearbearingislargerthantheforebearing.
Anditiscausedbythepoorcoolingconditionoftheinnerring.
TheanalysisofthetransienttemperaturefieldWhenthespindlesystemistheanalysisofthetransienttemperaturefieldtogetthebearingtemperaturecurveandthethermalequilibriumtimebysettingtheoperatingtimeof65min.
Fig.
4arethecontoursofthetemperaturefieldatdifferenttimepoints.
1600s2400s3200s3600sFig.
4ContoursofthetemperaturefieldatdifferenttimepointsThespindlesystemhasreachedthethermalequilibriumafterrunning60min.
Thehighesttemperaturesoftheforebearingandrearbearingare34.
19C°and35.
9C°.
ExperimentaltestTheautomatictestsystemofmechanicalspindlecharacteristicisusedforthetemperaturerisetestwhichisinthestatusoftheofmechanicalspindletorqueoutput,theloadandwithoutloadateachspeed.
Thetestsystemconsistsofthemachinebase,torqueandspeedsensors,industrialcomputer,ervomotor,multi-channeltemperaturecontrolinstrumentandsoon.
Thetestprincipleisthatthespindleconnectsthearresterdetentviacouplings,torqueandspeedsensorandthemotordrivesbyabeltdrivetomakethespindlerotatebychangingthebrakeexcitationcurrentmethodtotheloadcontrolforthespindlesystem.
Fig.
5istheoperatingprincipleoftheexperimentplatform.
Fig.
6istheexperimentdeviceofmechanicalspindlesystem.
Fig.
5OperatingprincipleoftheexperimentplatformFig.
6TheexperimentdeviceofmechanicalspindlesystemThetemperaturesensorsaredisposedwithintheouterringoftheforeandrearbearings,therearendsurfaceoftherearbearingandandoutersurfaceofthecase.
Fig.
7isthedistributionoftestpoints.
Atthespeedof2000r/minand4500r/min,thespindlesystemistestingtemperaturerisethewithoutload.
Whenthespindlesystemhasreachedtheequilibrium,wecanmeasurethetemperatureofeachofthekeyparts.
Wewilltaketestpoint2andtestpoint8forexampleandcanseethechangesinthebearingtemperaturewithtime.
Fig.
8isthetemperaturerisecurvefortestpoint2and8atthespeedof2000r/minand4500r/min.
123456789111210Fig.
7Thedistributionoftestpoints05101520253035404550556065202224262830323436T/°Ct/minSimulationvalueExperimentalvalue05101520253035404550556065202224262830323436T/°Ct/minSimulationvalueExperimentalvaluea.
Thetemperatureoftestpoint2(Speedof2000r/min)b.
Thetemperatureoftestpoint8(Speedof2000r/min)051015202530354045505560652022242628303234363840424446T/℃t/minSimulationvalueExperimentalvalue0510152025303540455055606520222426283032343638404244T/℃t/minSimulationvalueExperimentalvaluec.
Thetemperatureoftestpoint2(Speedof4500r/min)d.
Thetemperatureoftestpoint8(Speedof4500r/min)Fig.
8Temperaturerisecurvefortestpoint2and8(Speedof2000r/minand4500r/min)AscanbeseenfromFig.
8,wecanseethattherearesomeerrorscomparedwithexperimentaldataandsimulationdata.
Butthereisthesameupwardtrendbasicallythatexplainsthemodelisreliable.
Whenthespindlespeedis2000r/minandthesystemhasbeenrunningfor60mins,thesystemhasreachedsteadystatetemperature.
Andthehighesttemperaturesoftestpoint2and8are34.
19C°and35.
9C°.
Therearemoreobviouschangesofthetemperaturerisewhenthespindlesystemisrunningatthebeginning.
Thetemperaturerisechangessmallerafter55minandreachessteadystateabout57.
5min.
Whenthespindlespeedis4500r/min,thespindlesystemrisesfasterbefore52.
5minandreachesequilibriumabout55min.
Next,wewilltestthetemperaturerisewhenthespindlespeedare1000r/min,1500r/min,2500r/min,3000r/min,3500r/minand4000r/min.
Asthekeypartsofthetestpoints2and8forexample,WecanobtainthemaximumtemperatureofeachtestpointunderdifferentspeedsasshowninFig.
9.
05001000150020002500300035004000450026283032343638404244T/℃Speed(r/min)Testpoint2Testpoint8Fig.
9SpindletemperatureatdifferentspeedsAscanbeseenfromFig.
9,asthespindlespeedincreases,thetemperatureriseofthebearingsismoreandmorehigher.
Andthetestpoint2isslightlyhigherthanthetestpoint8.
Whenthespindlespeedchanges1000to3000r/min,thebearingtemperaturechangesmoreobviously.
Thechangeofthetemperatureisflatrelativelywhenthespindlespeedchanges3000to4500r/min.
ConclusionInthispaper,itisconductedthethermalanalysisofthespindlesystemcombiningthemethodofthefiniteelementanalysiswithexperimentalverificationandresultinginthefollowingconclusions:(1)Theaboveanalysisshowsthatthesimulationmodelofthemachinespindleisreliable.
Theresultoferrorsislessthan3%comparedthesimulationdatawiththeexperimentaldata.
(2)Whenthespindlespeedischanging1000to3000r/min,thetemperatureofbearingshavechangedmoreobviously.
Thechangeofthetemperatureisflatrelativelywhenspindlespeedischanging3000to4500r/min.
Itindicatesthatthespeedimpactsthetemperaturegreaterunderlowspeeds.
Andforthehighspeed,thetemperatureisimpacttothespeedrelativelysmall.
Forthespindle,whichistheratedspeedof4500r/min,thetemperaturechangesrapidlyunderitstwo-thirds'ratedspeed.
Whilethespeedismorethantwo-thirds'ratedspeed,thetemperaturechangesslowly.
(3)Thespindlesystemhasreachedthedifferentthermalequilibriumtimeatdifferentspindlespeeds.
Thehigherthespeedis,theshorterthespindlehasreachedthermalequilibriumtime.
(4)Theprecisionspindleof170CP06hasreachedthethermalequilibriumatratedspeedfor55min.
Thehighesttemperatureis45.
2C°thatoccurstothebearbearing.
References[1]D.
A.
Krulewich,Temperatureintegrationmodelandmeasurementpointselectionforthermallyinducedmachinetoolerrors,Mechantronics,1998,8:395~412.
[2]ZhenZhu,PenghaoHu,YiTao.
Theanalysisofthree-dimensionalspindletemperaturefieldandthermaldeformation[J].
Tooltechnology,2008(4):66-68.
[3]Choijin-Kyung,LeeDai-Gil.
Thermal-characteristicsofthespindlebearingsystemwithagearlocatedonthebearing[J].
[4]M.
H.
Attia,L.
Kops,ComputersimulationofnonlinearthermoPlastiebehaviorofajointinmaehinetoolstructureanditseffeetonthermaldeformation,TransaetionsoftheASME,JournalofEnginneringforIndustry,101(1979)355-361.
[5]CeGuo,QinghongSun.
Thethermal-characteristics'analysisofthehigh-speedandhigh-precisionCNClathespindlesystemandthermaldeformation.
JournalofSoutheastUniversity,2005,35(2).
[6]WenPeng,YouweiHong.
Thethermal-characteristicsnumericalanalysisoffive-axisgantrymachiningcenter'sspindlesystem[J].
ModularMachineTool&AutomaticManufacturingTechnique.
2005(08).
[7]XingjuanYing,HaolinLi.
ThefiniteelementanalysisofCNCmachinetoolspindle'ssystemthermalcharacteristics[J]tooltechnology,2010,4(1):38-40.
[8]DatongQin.
Bearing.
Beijing:ChemicalIndustryPress.
2013.
3(5).
[9]XinshengLiBobaoZhao,Yaping.
Thethermalsimulationanalysisofhigh-speedspindle[J]tooltechnology,2012(4):64-32.
[10]F.
P.
Incropera,D.
P.
DeWitt,T.
L.
Bergman.
FundamentalsofHeatandMassTransfer[M].
2012.
[11]ChongzhiGuo,LeXiao.
Asequencecouplingmethodfornumericalsimulationoftemperature[J].
ChemicalIndustryandEngineeringProgress.
2010(09).
[12]ShimingYang,WenquanTao,HeatTransfer[M]Beijing:HigherEducationPress,1998.
[13]XiangqianKong.
Thefiniteelementmethodinheattransfer.
Beijing:SciencePress,1986.
[14]CanZhou,YuhuiHe,GuilingDeng.
Thetransienttemperaturefieldanalysisandtestingofhigh-speedspindle[J].
ComputerSimulation,2012,29(2):372-377.
com,b474891749@qq.
comKeywords:mechanicalspindle;thermalanalysis;temperaturefield;thermalbalancetime.
Abstract:ThearticleisbasedonprecisionCNClathespindlesystemofthe170CP06astheresearchobject.
Thesteadyandtransienttemperaturefieldmodelofthemechanicalspindleisestablishedbyusingthefiniteelementanalysismethod.
Astheheatratefortheloadandtheconvectiveheattransfercoefficientfortheboundaryconditionsforthermalanalysis,thetemperaturefieldofspindlesystemisinvestigatedtogetthesteadystatetemperaturefielddistributionandthermalbalancetimeofthespindlesystem.
Inordertoverifythecorrectnessofthemodel,thethermalexperimentswithoutloadareexecutedtothekeypartsofthetemperatureofthespindlesystematdifferentspeeds.
Comparedwiththesimulationresults,ithasaverygoodagreementwiththereliabilityofthemodel.
Anditprovidesatheoreticalbasisforcontrollingthetemperatureriseofthespindlesystem.
IntroductionWiththerapiddevelopmentofmodernmachinerymanufacturingtechnology,therequirementsofmachine'saccuracyarealsobecominghigherandhigher.
Inthehigh-speedandprecisionmachinetools,theproblemofmachiningerrorcausedbythermaldeformationalsohasbecomeincreasinglyserious.
Alargenumberofexperimentalstudiesshowthethermalerroristhelargesterrorsourceofmachinetoolsaccountingfor40%to70%inthetotalerrorofthemachine[1].
Thespindleisoneoftheimportantcomponentsofthemachine,anditsperformanceaffectstheoveralllevelofthemachinedirectly.
Whenthemechanicalspindleisworking,theinternalheatsourceofthespindlecomesformtheheatgeneratedbythefrictionofhigh-speedrotation'sbearing.
Whenthetemperaturehasrisen,therelativespatialpositionandsizeofthespindleandotherpartsofthemachinewillbedifferentfromtheprevioustemperature.
Itwillformadifferenttemperaturefieldandproducedifferentdegreesofthermaldeformation[2].
Therefore,thethermalcharacteristicsofresearchandanalysisonthespindlesystemiscrucialtoensuretheaccuracyofthemachine.
Itisoneofthekeytechnologiestobeconsideredinhighprecisionmachinetools.
Thethermalcharacteristicsanalysisofthespindlesystemistostudythedistributionofthetemperaturefield.
Atpresent,therearemanyscholarswhostudythethermalcharacteristicsofmachinetoolspindlesystemathomeandabroad.
Forexample,JinKyungChoiofSouthKoreastudiedthermalcharacteristicsforthespindleandbearingsystemwiththefiniteelementmethod[3].
M.
H.
AttiafromCanadaanalyzedthewholetemperaturefieldofthemachineusingthefiniteelementmethod[4].
CeGuoandQinghongSunfromSoutheastUniversityhavealreadyestablishedafiniteelementmodelofthehigh-speedprecisionlathespindlecomponents'temperaturefield[5].
YouweiHongestablishedthefiniteelementmodelofthegantrymachiningcenterandsimulatedthetemperaturefielddistributionandvariation[6].
ThearticleisbasedonCNClatheprecisionspindlesystemofthe170CP06astheresearchobject.
Thetemperaturefieldmodelofthemechanicalspindleisestablishedanditisconductedthesteady-stateandtransientthermalanalysisofthespindlesystem.
Thetemperaturefieldofspindlesystemisinvestigatedtogetthetemperaturefielddistributionandthermalbalancetimeofthespindlesystem.
Thethermalexperimentswithoutloadarecarriedoutinordertoverifythereliabilityofthemodel.
CalculationofthethermalparametersTheheatsourceisthefoundationofthespindletemperaturefieldresearch.
Theheatsourceofthespindlesystemincludescuttingheatandbearingfrictionheat.
Thecuttingheatinthemachiningprocessistakenawaybycoolantliquidandswarf.
Therefore,theheatsourceofthespindlemaybemainlythebearingfrictionalheat.
CalculationofthecalorificvalueTherollingbearing'sheatismainlygeneratedbythebearingfrictionaltorque.
Theformulais41.
04710fHnM=*(1)Intheformula,Hfisthecalorificvalueofthebearing;nisthespindlespeed;M0isthebearingfrictionaltorque.
Thebearingfrictionaltorqueisthesumofthebearingrollingfriction,slidingfrictionandlubricantfrictionwhichhavegeneratedtoblockthebearingrunningtorque.
Palmgren[7]deducedtheempiricalformulawhichcalculatesthebearingfrictiontorque.
Thebearingfrictionaltorqueiscalculatedas01MMM=+(2)Intheformula,M0isrelatedtotheviscosityofthelubricant.
M1isrelatedtotheloadofthebearingregardlessofspeed.
ItonlyconsidersM0withoutload.
Palmgrenconfirmedtheexpressionusingempiricalmethods:72/3300=10()mMfnDν2000nν≥(3)730016010mMfD=*2000nν<(4)Intheformula,νisthekinematicviscosityofthelubricantinthebearingoperatingtemperature,mm2/s;0fisthecoefficientrelatedtothebearingtypesandlubrication,mDistheaveragediameterofthebearing,mm,0.
5()mDDd=+.
Whenthespindlesystemisanalyzed,thethermalloadisloadedbythewayofbearingtheheatrate.
Theformulais[9]3(/)fHqWmV=(5)Intheformula,Visthevolumeoftheheatsource;22)2/(bmDDVπ=,andDbisthediameteroftherollingelements.
Calculatedbytheequation(1)to(5),whenthespindlespeedis2000r/min,wecangettheheatratesoftheforeandrearbearingtobe342704.
4W/m3and348161.
76W/m3.
CalculationoftheheattransfercoefficientAccordingtotheheattransfertheory[10],wecanknowtheheattransferwayaretheheatconduction,theconvectionandthethermalradiation,thelossoftheradiationheatislessforthespindlesystem.
Whenweareanalyzingthetemperaturefieldofthespindlesystemonlytoconsiderthethermalconductionandtheconvectionheattransfer.
Thethermalconductivitydependsonthethermalconductivityofthecomponentsinthespindlesystem.
Theconvectiveheattransferistheconvectionofthespindlesurfaceandtheair.
Theconvectiveheattransferisformedbydrivingtherotationofthespindlearoundtheairbetweenthecaseandthespindle.
ThecoefficientoftheheattransferdependsonthecriterionofNusselt[12].
/cchNlλ=(6)Intheformula,chisthecoefficientoftheheattransfer;λisthethermalconductivityoftheair;NisthecoefficientofNusselt;clisthefeaturesize.
TheNusseltformulaoftheforcedconvectionis23130.
133RePrN=5Re4.
3100.
7Pr670)<*<<(,(7)AccordingtoReynoldsCriterion,wecanknowRe=/cculν(8)Intheformula,ReistheReynoldsnumber;PristhePrandtlnumberofthefluid;cuistheaveragevelocityoftheair;νisthecoefficientoftheair'smotionviscosity.
Whenthespindlerotatesbyhighspeed,theaveragevelocityoftheairis[13]=/60cudnπ(9)1122=nndldldldl++(10)12nllll11)Intheformula,distheaveragediameterofthespindle;nisthespeedofthespindle.
Calculatedbytheequation(6)to(11),whenthespindlespeedis2000r/min,wegeteachheattransfercoefficientswhichare26.
62/()Wmk,35.
632/()Wmk,38.
32/()Wmk,32.
52/()Wmk,35.
22/()Wmk.
FiniteelementmodelofthespindlesystemTheprecisionspindlesystemofthe170CP06ismainlycomposedofthespindle,case,beltpulley,bearingcoverandtheangularcontactballbearings,etc.
Themotordrivesbyabeltpulleymountedontheshafttoprovideadrivingforceforthespindle.
Themainparametersofthespindleis:ItsmaterialisalloySteel.
Thetotallengthis497mm.
Themaximumdiameterofthespindleismm100φ.
Theratedspeedofthespindlesystemis4500r/min.
Themaximumpoweris35kWandthemaximumtorqueis180N.
m.
Fig.
1isthestructurediagramforspindlesystem.
1—Bignut2—Beltpulley3—Leftcover4—Case5—Rightcover6—Spindle7—Forebearing8—RearbearingFig.
1StructurediagramforspindlesystemThemodelofthespindlesystemisestablishedbyusingthethree-dimensionalmappingsoftware—SoildWorks.
Anditsimplifiesappropriatelythestructurethatinfluencesanalysisresultsless.
Accordingtothespindleoftheboundaryconditionsandheattransfercharacteristics,Simplifiedsolidmodelisintroducedtothefiniteelementanalysissoftwaretobemeshingofthegrid[12].
Fig.
2isasimplifiedandmeshingmodelofthespindlesystem.
Theentiremodelhas128,143unitsand232,855nodes.
Fig.
2MeshingofthespindlesystemSimulationanalysisofthespindlesystem'stemperaturefieldThethermalanalysisisestablishedinthesoftwareoffiniteelementanalysis.
Thematerialofthespindleandbearingaredefinedasalloysteel.
Theambienttemperatureis26C°.
Accordingtotheboundaryconditionsofthespindleandthecharacteristicsoftheheattransfer,theheatgenerationrateoftheforeandrearbearingsis342704.
4W/m3and348161.
76W/m3whichareappliedtotheforeandrearbearings.
Thecoefficientsoftheheattransferconvectionareaddedtotherespectivemembersurfacespindlesystemasboundaryconditions.
Itisconductedthesteady-stateandtransientthermalanalysisofthespindlesystem.
TheanalysisofthesteadytemperaturefieldWhenthespindlespeedis2000r/min,wecangetthesimulationofthesteady-statetemperaturefieldresultinginthesteady-statetemperaturefieldcontourofthespindlesystem.
AsisshowninFig.
3.
Fig.
3Steady-statetemperaturedistributionofspindlesystemFig.
3showsthatthemaximumtemperatureofthespindlesystemappearsattheinnerringoftherearbearing.
Itstemperatureis38.
5C°.
Themaximumtemperatureriseis12.
5C°.
Theheatoftherearbearingislargerthantheforebearing.
Anditiscausedbythepoorcoolingconditionoftheinnerring.
TheanalysisofthetransienttemperaturefieldWhenthespindlesystemistheanalysisofthetransienttemperaturefieldtogetthebearingtemperaturecurveandthethermalequilibriumtimebysettingtheoperatingtimeof65min.
Fig.
4arethecontoursofthetemperaturefieldatdifferenttimepoints.
1600s2400s3200s3600sFig.
4ContoursofthetemperaturefieldatdifferenttimepointsThespindlesystemhasreachedthethermalequilibriumafterrunning60min.
Thehighesttemperaturesoftheforebearingandrearbearingare34.
19C°and35.
9C°.
ExperimentaltestTheautomatictestsystemofmechanicalspindlecharacteristicisusedforthetemperaturerisetestwhichisinthestatusoftheofmechanicalspindletorqueoutput,theloadandwithoutloadateachspeed.
Thetestsystemconsistsofthemachinebase,torqueandspeedsensors,industrialcomputer,ervomotor,multi-channeltemperaturecontrolinstrumentandsoon.
Thetestprincipleisthatthespindleconnectsthearresterdetentviacouplings,torqueandspeedsensorandthemotordrivesbyabeltdrivetomakethespindlerotatebychangingthebrakeexcitationcurrentmethodtotheloadcontrolforthespindlesystem.
Fig.
5istheoperatingprincipleoftheexperimentplatform.
Fig.
6istheexperimentdeviceofmechanicalspindlesystem.
Fig.
5OperatingprincipleoftheexperimentplatformFig.
6TheexperimentdeviceofmechanicalspindlesystemThetemperaturesensorsaredisposedwithintheouterringoftheforeandrearbearings,therearendsurfaceoftherearbearingandandoutersurfaceofthecase.
Fig.
7isthedistributionoftestpoints.
Atthespeedof2000r/minand4500r/min,thespindlesystemistestingtemperaturerisethewithoutload.
Whenthespindlesystemhasreachedtheequilibrium,wecanmeasurethetemperatureofeachofthekeyparts.
Wewilltaketestpoint2andtestpoint8forexampleandcanseethechangesinthebearingtemperaturewithtime.
Fig.
8isthetemperaturerisecurvefortestpoint2and8atthespeedof2000r/minand4500r/min.
123456789111210Fig.
7Thedistributionoftestpoints05101520253035404550556065202224262830323436T/°Ct/minSimulationvalueExperimentalvalue05101520253035404550556065202224262830323436T/°Ct/minSimulationvalueExperimentalvaluea.
Thetemperatureoftestpoint2(Speedof2000r/min)b.
Thetemperatureoftestpoint8(Speedof2000r/min)051015202530354045505560652022242628303234363840424446T/℃t/minSimulationvalueExperimentalvalue0510152025303540455055606520222426283032343638404244T/℃t/minSimulationvalueExperimentalvaluec.
Thetemperatureoftestpoint2(Speedof4500r/min)d.
Thetemperatureoftestpoint8(Speedof4500r/min)Fig.
8Temperaturerisecurvefortestpoint2and8(Speedof2000r/minand4500r/min)AscanbeseenfromFig.
8,wecanseethattherearesomeerrorscomparedwithexperimentaldataandsimulationdata.
Butthereisthesameupwardtrendbasicallythatexplainsthemodelisreliable.
Whenthespindlespeedis2000r/minandthesystemhasbeenrunningfor60mins,thesystemhasreachedsteadystatetemperature.
Andthehighesttemperaturesoftestpoint2and8are34.
19C°and35.
9C°.
Therearemoreobviouschangesofthetemperaturerisewhenthespindlesystemisrunningatthebeginning.
Thetemperaturerisechangessmallerafter55minandreachessteadystateabout57.
5min.
Whenthespindlespeedis4500r/min,thespindlesystemrisesfasterbefore52.
5minandreachesequilibriumabout55min.
Next,wewilltestthetemperaturerisewhenthespindlespeedare1000r/min,1500r/min,2500r/min,3000r/min,3500r/minand4000r/min.
Asthekeypartsofthetestpoints2and8forexample,WecanobtainthemaximumtemperatureofeachtestpointunderdifferentspeedsasshowninFig.
9.
05001000150020002500300035004000450026283032343638404244T/℃Speed(r/min)Testpoint2Testpoint8Fig.
9SpindletemperatureatdifferentspeedsAscanbeseenfromFig.
9,asthespindlespeedincreases,thetemperatureriseofthebearingsismoreandmorehigher.
Andthetestpoint2isslightlyhigherthanthetestpoint8.
Whenthespindlespeedchanges1000to3000r/min,thebearingtemperaturechangesmoreobviously.
Thechangeofthetemperatureisflatrelativelywhenthespindlespeedchanges3000to4500r/min.
ConclusionInthispaper,itisconductedthethermalanalysisofthespindlesystemcombiningthemethodofthefiniteelementanalysiswithexperimentalverificationandresultinginthefollowingconclusions:(1)Theaboveanalysisshowsthatthesimulationmodelofthemachinespindleisreliable.
Theresultoferrorsislessthan3%comparedthesimulationdatawiththeexperimentaldata.
(2)Whenthespindlespeedischanging1000to3000r/min,thetemperatureofbearingshavechangedmoreobviously.
Thechangeofthetemperatureisflatrelativelywhenspindlespeedischanging3000to4500r/min.
Itindicatesthatthespeedimpactsthetemperaturegreaterunderlowspeeds.
Andforthehighspeed,thetemperatureisimpacttothespeedrelativelysmall.
Forthespindle,whichistheratedspeedof4500r/min,thetemperaturechangesrapidlyunderitstwo-thirds'ratedspeed.
Whilethespeedismorethantwo-thirds'ratedspeed,thetemperaturechangesslowly.
(3)Thespindlesystemhasreachedthedifferentthermalequilibriumtimeatdifferentspindlespeeds.
Thehigherthespeedis,theshorterthespindlehasreachedthermalequilibriumtime.
(4)Theprecisionspindleof170CP06hasreachedthethermalequilibriumatratedspeedfor55min.
Thehighesttemperatureis45.
2C°thatoccurstothebearbearing.
References[1]D.
A.
Krulewich,Temperatureintegrationmodelandmeasurementpointselectionforthermallyinducedmachinetoolerrors,Mechantronics,1998,8:395~412.
[2]ZhenZhu,PenghaoHu,YiTao.
Theanalysisofthree-dimensionalspindletemperaturefieldandthermaldeformation[J].
Tooltechnology,2008(4):66-68.
[3]Choijin-Kyung,LeeDai-Gil.
Thermal-characteristicsofthespindlebearingsystemwithagearlocatedonthebearing[J].
[4]M.
H.
Attia,L.
Kops,ComputersimulationofnonlinearthermoPlastiebehaviorofajointinmaehinetoolstructureanditseffeetonthermaldeformation,TransaetionsoftheASME,JournalofEnginneringforIndustry,101(1979)355-361.
[5]CeGuo,QinghongSun.
Thethermal-characteristics'analysisofthehigh-speedandhigh-precisionCNClathespindlesystemandthermaldeformation.
JournalofSoutheastUniversity,2005,35(2).
[6]WenPeng,YouweiHong.
Thethermal-characteristicsnumericalanalysisoffive-axisgantrymachiningcenter'sspindlesystem[J].
ModularMachineTool&AutomaticManufacturingTechnique.
2005(08).
[7]XingjuanYing,HaolinLi.
ThefiniteelementanalysisofCNCmachinetoolspindle'ssystemthermalcharacteristics[J]tooltechnology,2010,4(1):38-40.
[8]DatongQin.
Bearing.
Beijing:ChemicalIndustryPress.
2013.
3(5).
[9]XinshengLiBobaoZhao,Yaping.
Thethermalsimulationanalysisofhigh-speedspindle[J]tooltechnology,2012(4):64-32.
[10]F.
P.
Incropera,D.
P.
DeWitt,T.
L.
Bergman.
FundamentalsofHeatandMassTransfer[M].
2012.
[11]ChongzhiGuo,LeXiao.
Asequencecouplingmethodfornumericalsimulationoftemperature[J].
ChemicalIndustryandEngineeringProgress.
2010(09).
[12]ShimingYang,WenquanTao,HeatTransfer[M]Beijing:HigherEducationPress,1998.
[13]XiangqianKong.
Thefiniteelementmethodinheattransfer.
Beijing:SciencePress,1986.
[14]CanZhou,YuhuiHe,GuilingDeng.
Thetransienttemperaturefieldanalysisandtestingofhigh-speedspindle[J].
ComputerSimulation,2012,29(2):372-377.
- formulaqq空间电脑版特别关心相关文档
- 2012年秋季福建省公务员考试行测真题与答案
- 贷款qq空间电脑版特别关心
- 孩子qq空间电脑版特别关心
- 排除qq空间电脑版特别关心
- 天气四年级上册科学教案我们关心天气∣教科版
- 宝宝新生儿出生特别要关心的问题
木木云35元/月，美国vps服务器优惠,1核1G/500M带宽/1T硬盘/4T流量
木木云怎么样?木木云品牌成立于18年，此为贵州木木云科技有限公司旗下新运营高端的服务器的平台，目前已上线美国中部大盘鸡，母鸡采用E5-267X系列，硬盘全部组成阵列。目前，木木云美国vps进行了优惠促销，1核1G/500M带宽/1T硬盘/4T流量,仅35元/月。点击进入：木木云官方网站地址木木云优惠码：提供了一个您专用的优惠码： yuntue目前我们有如下产品套餐：DV型 1H 1G 500M带宽...
六一云互联（41元）美国（24元）/香港/湖北/免费CDN/免费VPS
六一云互联六一云互联为西安六一网络科技有限公司的旗下产品。是一个正规持有IDC/ISP/CDN的国内公司，成立于2018年，主要销售海外高防高速大带宽云服务器/CDN，并以高质量.稳定性.售后相应快.支持退款等特点受很多用户的支持！近期公司也推出了很多给力的抽奖和折扣活动如：新用户免费抽奖，最大可获得500元，湖北新购六折续费八折折上折，全场八折等等最新活动：1.湖北100G高防：新购六折续费八折...
美国多IP站群VPS商家选择考虑因素和可选商家推荐
如今我们很多朋友做网站都比较多的采用站群模式，但是用站群模式我们很多人都知道要拆分到不同IP段。比如我们会选择不同的服务商，不同的机房，至少和我们每个服务器的IP地址差异化。于是，我们很多朋友会选择美国多IP站群VPS商家的产品。美国站群VPS主机商和我们普通的云服务器、VPS还是有区别的，比如站群服务器的IP分布情况，配置技术难度，以及我们成本是比普通的高，商家选择要靠谱的。我们在选择美国多IP...
qq空间电脑版特别关心为你推荐
-
iprouteip route 0.0.0.0 0.0.0.0 s0/0/0 中s0/0/0 指的是本地的还是??重庆网站制作我想做个网站，我是重庆的人。想在本地找个做网站的公司，请教一下在重庆那个公司比较好一点，，，，谢谢邮件eset台北市cuteftp抢米网怎么样才能在小米官方网站抢到手机？加多宝和王老吉王老吉和加多宝谁好喝点？腾讯公司电话腾讯公司总部电话多少中国保健养猪网猪场基本保健包括哪些方面？佛山海虹广东海虹药通电子商务有限公司怎么样？灌水机谁知道哪个好点的灌水机的地址？