外文翻译--机械与液压的发展前景.doc

TheprospectsforthedevelopmentofmechanicalandhydraulicWiththecontinuousdevelopmentofhumansociety,thelandcouldbeopenresourcesdepleted,theworldisgraduallyturningtotheocean,openanduseofmarineresourceshasplayedanincreasinglyimportantroleinthedevelopmentofcountries.Disputesbetweencountriesandregionsoftheresultingfriction.Sincethebeginningofthenewcentury,withtheoceanreefsandthescrambleforresourcesintensifies,sealanessecuritysituationdeterioratingsituationofthecompetinginterestsatseawillbemoresevere,especiallyintheUnitedStates,Japan,Russia,IndiaandothercountriesforthegrowthoftheNavyadoptedamulti-kindsofmeasures,warlordscontendsituation.Intheeraoffullimplementationoftheopenseabackgroundconditions,thetheNavyshoulderthesacredmissiontosafeguardnationalsecurity,todefenditssovereignty,safeguardnationalmaritimerightsandinterests.Atthesametimeduetothegrowingeconomicsituationofourcountryandourincreasinglypowerfulmilitarytechnology,andtheoutsideworldhasgraduallycloseup.However,Chinahasarelativelywidefieldofports,maritimetransportisthebestwaytocontacttheoutsideworld.Maritimetrafficwillbeusedinships,landcontactmustusethespringboard,soIwillbethespringboarddevicedesign.Springboardastheirownshipanimportantpartoftheshipclosetotheshore,canbeusedastheaccessbridgesupportequipment.Realitywehaveseenboardingladdergivesusthefeelingisveryheavy,inconvenientforcruiseshipsisfeasible,butifforaircraftcarriersorwarships,itcertainlydoesnotmeettherequirements(oncethepierisnotitwillcausetrouble),itisnecessarytodevelopalightweightandconvenientandsafetobeabletoadapttoamilitaryboardingladdersystem,thisismytopichavetodotoachievetherequirements.Idesignedaspringboarddevicenotonlydesignedanumberofmechanicaltransmission,hydraulictransmissionstillintheoriginalbasis.Withhydraulicdriveoftheoutstandingadvantages:easytoimplementfrequentstarting,commutationandvariablespeed,andlessimpactontheshipspowerplant；inertia,highprecisionpositioncontrol；forceandtorqueoftheoutputcanbelarge,butthelinespeedandthespeedcanbeverylow,verysmallsizeandweight；widespeedrange.Therefore,thehydraulicdriveisnowwidelyusedinalltypesofvessels.TheissueisChinasfirstaircraftcarrier,thehydraulicdesignoftheboardingladder.Springboard(boardingladder)ismainlyusedforwarshipstothepierandweightlimitsuppliesthroughormigrate.Theboardingladdersystemtotheelectriccanalsobemanuallymanuallybyhandpump,theuseofthehandpumpisdesignedtopreventtheboardingladderincaseofpowerfailurecannotbeused.Inrecentyears,Chinasnationaleconomymaintainedamomentumofrapiddevelopment,majornationalinfrastructureprojectsinfullswing,thesustainabledevelopmentofdomesticagriculturalmachinery,constructionmachinery,aviation,railway,highway,automobile,shipbuildingandotherindustries,strongdemandforproductionandconstructionwilldrivethecontinuedgrowthofthehydraulictechnology.Bytheearly2000s,thegeneraltrendofdevelopmentofthemachinerymanufacturingindustryasthefourmodernizations:(1)Flexibility:theprocessequipmentandprocessroutecanbeappliedtotheneedsoftheproductionofavarietyofproducts,canbeappliedtotherapidreplacementoftheprocess,replacetheproductneeds；(2)Agile:productstomarketfortheshortestpreparationtimereduction,machineryfactorysteeringmechanismflexibility；(3)Intelligent:animportantpartoftheflexibleautomation,itisanewdevelopmentandextensionoftheflexibleautomation.Humansnotonlytogetridoftheheavymanuallabor,butalsofromthetediouscalculations,analysisofmentalliberation,inordertohavemoreenergytoengageinhigh-levelcreativework.Theintellectualizedpromoteflexibleproductionsystemhasbetterjudgmentandabilitytoadapt.Theearly2000s,theupgradingofproductswillcontinuetospeedupawidevarietyofneedsincreasing.AccordingtothestatisticsoftheUnitedStates,JapanandEuropeandotherdevelopedcountries,from1975to1995,thetypeofmechanicalpartsincreasedby40%to50%,from75%to85%ofthestaffdonotdealdirectlywiththematerial,turntodealwiththeinformation.80%to88%oftheactivitydoesnotdirectlyincreasethevalue-addedproducts,productprocess,organizationandmanagementofincreasinglycomplex.Design,processpreparationworkaboutorderingmorethan60%ofthetotaltimeforthecompletionoftheuser.Ontheotherhand,inthefiercemarketcompetition,supplyandproductqualityoftenplaysamoreimportantrolethanprice.Agilityisamajorissueinfrontofthemachinerymanufacturingindustry.Technicallytoachievetheflexibility,tobringaboutchangeintheorganizationofproduction,thesearemachinerymanufacturingenterprisesurgentevent；(4)informationtechnology:machinerymanufacturingindustrywillnolongermatterandenergybymeansofthepowerofinformationtoproducevalue,butbythehelpofthepowerofmatterandenergyproductionvalue.Therefore,theinformationindustryandintelligenceindustrywillbecometheleadingindustryofthesociety.Machinerymanufacturingwillalsobeledbytheinformation,andtheuseofadvancedproductionmode,newmechanicalmanufacturingofadvancedmanufacturingsystems,advancedmanufacturingtechnologyandadvancedorganizationalmanagementway.Thebeginningofthe21stcentury,animportantfeatureofthemachinerymanufacturingindustryinitsglobalization,networking,virtualization,intelligentandgreenenvironmentalprotectioncoordinationmanufacturing.Idesignedaspringboarddevicenotonlydesignedanumberofmechanicaltransmission,hydraulictransmissionstillintheoriginalbasis.Withhydraulicdriveoftheoutstandingadvantages:easytoimplementfrequentstarting,commutationandvariablespeed,andlessimpactontheshipspowerplant；inertia,highprecisionpositioncontrol；forceandtorqueoftheoutputcanbelarge,butthelinespeedandthespeedcanbeverylow,verysmallsizeandweight；widespeedrange.Therefore,thehydraulicdriveisnowwidelyusedinalltypesofvessels.Acompletehydraulicsystemconsistsoffiveparts,namely,powercomponents,actuators,controlcomponents,auxiliarycomponents(Annex),andhydraulicoil.PowercomponentsTheroleofthepowerelementistheprimemovermechanicalenergyisconvertedintofluidpressure,meansofpumpsinthehydraulicsystem,itprovidespowertotheentirehydraulicsystem.Hydraulicpumpstructuregenerallyintheformofgearpumps,vanepumpsandpistonpumps.ActuatorActuators(suchashydrauliccylindersandhydraulicmotors)pressureoftheliquidcanbeconvertedtomechanicalenergytodrivetheloadforlinearreciprocatingorrotarymotion.ControlcomponentsThecontrolelement(i.e.,thevarioushydraulicvalvestocontrolandregulatethepressureoftheliquid,flowrateanddirection)inthehydraulicsystem.Accordingtothedifferentcontrolfunctions,hydraulicvalvescanbedividedintothepressurecontrolvalves,flowcontrolvalvesanddirectionalcontrolvalves.Pressurevalve(safetyvalve)isdividedintobenefitsflowcontrolvalve,pressurereducingvalves,sequencevalves,pressurerelay；flowcontrolvalveincludesathrottlevalve,regulatingvalve,flowdiversionvalve；directionalcontrolvalveincludesaone-wayvalve,pilot-operatedcheckvalve,shuttlevalve,valve.Dependingonthecontrolmode,thehydraulicvalvescanbedividedintotheswitchcontrolvalvesetpointcontrolvalvesandproportionalcontrolvalve.AuxiliarycomponentsAuxiliarycomponentsincludingfueltanks,filters,tubingandfittings,seals,quick-changefittings,highpressureballvalve,hoseassemblies,pressurejoints,pressuregauge,oillevel,oiltemperaturemeter.HydraulicoilThehydraulicoilistheenergytransferinthehydraulicsystemoftheworkingmedium,avarietyofmineraloil,emulsion,oilhydraulicmoldingHopseveralcategories.Alittlemechanicalknowledgeallknow,theenergywillbeconvertedtoeachother,andtousethisknowledgetoexplainthepowerlossofthehydraulicsystemonthehydraulicsystemisbest,however,thehydraulicsystempowerontheonehandwillcauseenergyloss,sothatthesystemtheoverallefficiencyisdecreased,ontheotherhand,losethispartoftheenergywillbetransformedintoheat,sothatthetemperatureriseofthehydraulicoil,oildeterioration,resultinginhydraulicequipmentfailure.Therefore,thedesignofthehydraulicsystem,meettherequirements,butalsogivefullconsiderationtoreducethepowerlossofthesystem.First,fromthepowersource-pumptoconsider,takingintoaccountthediversificationoftheactuatorworkingconditions,highflow,lowpressuresystemsometimesneeds；sometimesneedsmallflowandhighpressure.SoIchosetolimitpressurevariabledisplacementpumpisappropriate,becausethistypeofpumpflowvarieswithchangesinsystempressure.Whenthesystempressureisreduced,theflowrateisrelativelylarge,canmeetrapidstrokeoftheactuator.Flowwhenthesystempressureincreasesanddecreasesaccordingly,tomeettheworkingstrokeoftheactuator.Thiswillnotonlymeettherequirementsoftheactuator,butalsomakemorereasonablepowerconsumption.Second,hydraulicoilflowingthroughthevarioustypesofhydraulicvalvesinevitableexistenceofpressurelossandflowlosses,accountforalargeproportionofthispartoftheenergylossinthetotalenergyloss.Therefore,areasonableselectionhydraulicpressurevalvetoadjustthepressureisalsoanimportantaspecttoreducethepowerloss.Flowvalvesystemflowadjustmentrangetoselectandtoensurethattheminimumstableflowtomeettherequirements,thepressureofthepressurevalveinthehydraulicequipmenttomeetthenormalworkofthecase,trytotakealowerpressure.Iftheactuatorhasagovernorsrequest,thenselectthespeedcontrolloop,itisnecessarytomeettherequirementsofthegovernor,butalsominimizepowerloss.Commonspeedcontrolloop:ThrottlingSpeedControlCircuit,volume,speedcontrolloop,thevolumethrottlespeedcontrolloop.ThrottlingSpeedlooppowerloss,low-speedstability.Volumespeedcontrolloopisneitheroverflowlosses,nothrottlinglosses,highefficiency,low-speedstability.Ifyouwanttomeetbothrequirementsatthesametime,canbeuseddifferentialpressurevariablevolumepumpandthrottlecontrolCircuits,andtothedifferentialpressureacrossthethrottleassmallaspossibleinordertoreducethepressureloss.Fourth,areasonablechoiceofhydraulicoil.Thehydraulicoilflowinginthepipeline,willappearinthestickiness,whileexcessivestickinesswillbegeneratedwhenagreaterinternalfriction,resultinginfluidheat,whileincreasingtheresistancetofluidflow.Whentheviscosityistoolow,couldeasilyleadtoleakage,andwillreducethevolumetricefficiencyofthesystem,therefore,generallychoosethesuitableviscosityandviscosity-temperaturecharacteristicsofgoodoil.Further,whenthefluidflowinthepipeline,butalsothereisfrictionalpressurelossandthelossofpartialpressureofasshortaspossible,thereforethedesignofconduitpipe,whilereducingelbow.IstoavoidtheabovereferredSomeworkinthehydraulicsystempowerloss,butthefactorsaffectingthepowerlossofthehydraulicsystemtherearemany,sowhentheparticulardesignofahydraulicsystemneedstobeconsolidatedtoconsidervariousotherrequirements.1)pollutionandwearofcomponentsOilpollutantscausedbythewearandtearofthec