彈性波箔型動壓氣體徑向軸承的動特性研究.pdf

1、南京航空航天大學碩士學位論文彈性波箔型動壓氣體徑向軸承的動特性研究姓名：劉思幸申請學位級別：碩士專業(yè)：機械設計及理論指導教師：馬希直201101彈性波箔型動壓氣體徑向軸承的動特性研究IIABSTRACTGasfoilbearingsareconstructedwithcrugatedbumpfoilasanelasticfoundationasmoothtopfoil.Theairisusedasalubricantofthebeari

2、ngs.therotissupptedbythefilmpressurewhichgeneratedintheclearancebetweenthetopfoiltherotoncetherotachievesacertainspeed.Therefethebearingcouldachieveanoncontactsuspension.Alargestructuraldampingisgeneratedduetotherelative

3、motionbetweenthebumpsthetopfoilbetweenthebumpsthehousing.Thedampingcouldinhibitthedevelopmentoftheselfexcitedlowfrequencywhirlofthebearingrotsystemindertoenhancethestabilityofthesystem.Aspringmodelofmultidegreeoffreedomh

4、asbeenusedtoanalyzetheelasticdefmationofthefoilcomparetheresultswiththeshellmodel.ThenthefilmthicknessequationtheReynoldsequationhavebeencoupledtogetthesteadystateperfmanceofgasfoilbearings.Thedynamicacteristicsofagasfoi

5、lbearinghasbeenrepresentedbyasetofspringdampingcoefficientswhicharefunctionsoftheeccentricityratiotherotatingspeedthewhirlfrequencyofthejournal.Inadditionthesecoefficientsaretheessentialparameterswhichcouldbeusedtodeterm

6、inethecriticalrotationalspeedanunbalanceresponseinvestigatethestability.Twoperturbationmethodshavebeenusedtodevelopamathematicmodelwhichcouldbeusedfthedynamiccoefficientscalculationofgasfoilbearings.Anelasticshellmodelas

7、pringmodelhavebeenusedtogetthedefmationofthebumpfoilthetopfoil.Thefinitedifferencemethodthefiniteelementmethodhavebeenusedtogetthedynamicacteristicsofthegasfoilbearings.Theresultshavebeencomparedtothepublishedexperimenta

8、ldatasothatthemodelhasbeenprovedtobecrectaccurate.Theeffectsoftheeccentricityratiotheshaftspeedthewhirlfrequencyonthedynamiccoefficientshavebeenalsodiscussed.Abearingperfmancetestrigafoilbearinghavebeendesigned.Inadditio

9、nthecriticalrotationalspeedhasbeencalculated.Therefethefoundationwkwhichhasbeendonecouldbeusedasareferencefthedesignofgasfoilbearings.Keywds:bumpfoilhydrodynamicgasbearingdynamicacteristicsperturbationmethodReynoldsequat