外文翻译--液压油.doc

徐州工程学院毕业设计（论文）1附录2英文原文HydraulicfluidsHydraulicfluidsarealargegroupoffluidsusedasthemotivemediuminhydraulicmachinery.Fluidtypesincludesyntheticcompounds,mineraloil,water,andwater-basedmixtures.Thefluidsarefoundinmachineryandequipmentrangingfrombrakes,powersteeringsystems,andtransmissionstobackhoes,excavators,garbagetrucksandindustrialshredders.Hydraulicsystemsareverycommoninaircraftflightcontrolsystems.Hydraulicsystemsliketheonesmentionedabovewillworkmostefficientlyifthehydraulicfluidusedhaslowcompressibility.BecauseindustrialhydraulicsystemsoperateathundredstothousandsofPSIandtemperaturesreachinghundredsofdegreesCelsius,severeinjuriesanddeathcanresultfromcomponentfailuresandcaremustalwaysbetakenwhenperformingmaintenanceonhydraulicsystems.Fireresistanceisapropertyavailablewithspecializedfluids.Theuseofhydraulicsystemsinaircraftalmostcertainlybeganwithbrakingsystems.citationneededAsaircraftperformanceincreasedinmid-20thcentury,theamountofforcerequiredtooperatemechanicalflightcontrolsbecameexcessive,andhydraulicsystemswereintroducedtoreducepiloteffort.Thehydraulicactuatorsarecontrolledbyvalves；theseinturnareoperateddirectlybyinputfromtheaircrew(hydro-mechanical)orbycomputersobeyingcontrollaws(flybywire).Seeflightcontrols.Hydraulicpowerisusedforotherpurposes.Itcanbestoredinaccumulatorstostartanauxiliarypowerunit(APU)forself-startingtheaircraftsmainengines.ManyaircraftequippedwiththeM61familyofcannonusehydraulicpowertodrivethegunsystem,permittingreliablehighratesoffire.Thehydraulicpoweritselfcomesfrompumpsdrivenbytheenginesdirectly,orbyelectricallydrivenpumps.Electricpumpscanprovidebothredundancyandthemeansofoperatinghydraulicsystemswithoutstartingtheengines,whichcanbeveryusefulduringmaintenance.Aircrafthydraulicfluidsfallundervariousspecifications:Exposuretohydraulicfluidsoccursmainlyintheworkplace.Drinkingcertaintypesofhydraulicfluidscancausedeathinhumans,andswallowingorinhalingcertaintypesofhydraulicfluidshascausednervedamageinanimals.Contactwithsometypesofhydraulicfluidscanirritate徐州工程学院毕业设计（论文）2yourskinoreyes.Thesesubstanceshavebeenfoundinatleast10ofthe1,428NationalPrioritiesListsitesidentifiedbytheEnvironmentalProtectionAgency(EPA).Whatishydraulicfluids?Hydraulicfluidsarealargegroupofliquidsmadeofmanykindsofchemicals.Theyareusedinautomobileautomatictransmissions,brakes,andpowersteering；forklifttrucks；tractors；bulldozers；industrialmachinery；andairplanes.Thethreemostcommontypesofhydraulicfluidsaremineraloil,organophosphateester,andpolyalphaolefin.SomeofthetradenamesforhydraulicfluidsincludeDurad,Fyrquel,Skydrol,Houghton-Safe,Pydraul,Reofos,Reolube,andQuintolubric.(UseoftradenamesisforidentificationonlyanddoesnotimplyendorsementbytheAgencyforToxicSubstancesandDiseaseRegistry,thePublicHealthService,ortheU.S.DepartmentofHealthandHumanServices.)Somehydraulicfluidshaveabland,oilysmellandothershavenosmell；somewillburnandsomewillnotburn.Certainhydraulicfluidsareproducedfromcrudeoilandothersaremanufactured.Whathappenstohydraulicfluidswhenitenterstheenvironment?Hydraulicfluidscanentertheenvironmentfromspills,leaksinmachinesthatusethem,orfromstorageareasandwastesites.Ifspilledonsoil,someoftheingredientsinhydraulicfluidswillstayontopandotherswillsinkintothegroundwater.Inwater,somehydraulicfluidsingredientswilltransfertothebottomandcanstaythereformorethanayear.Certainchemicalsinhydraulicfluidsmaybreakdowninair,soil,orwater,buthowmuchbreaksdownisntknown.Fishmaycontainsomehydraulicfluidsiftheyliveincontaminatedwater.HowmightIbeexposedtohydraulicfluids?Touchingorswallowinghydraulicfluids.Breathinghydraulicfluidsintheairnearmachineswherehydraulicfluidsareused.Touchingcontaminatedwaterorsoilnearhazardouswastesitesorindustrialmanufacturingfacilitiesthatuseormakehydraulicfluids.Howcanhydraulicfluidsaffectmyhealth?Littleisknownabouthowhydraulicfluidscanaffectyourhealth.Sincehydraulicfluidsareactuallymixturesofchemicals,someoftheeffectsseenmaybecausedbyadditivesinthehydraulicfluids.Inpeople,theeffectsofbreathingairwithhighlevelsofhydraulicfluidsarenotknown.Drinkinglargeamountsofsometypesofhydraulicfluidscancausepneumonia,intestinal徐州工程学院毕业设计（论文）3bleeding,ordeathinhumans.Weaknessofthehandswasseeninaworkerwhotouchedalotofhydraulicfluids.Rabbitsthatinhaledveryhighlevelsofonetypeofhydraulicfluidhadtroublebreathing,congestedlungs,andbecamedrowsy.Thenervoussystemsofanimalsthatswallowedorinhaledotherhydraulicfluidswereaffectedimmediatelywithtremors,diarrhea,sweating,breathingdifficulty,andsometimesseveralweekslaterwithweaknessofthelimbs,orparalysis.Theimmediateeffectsarecausedbecausehydraulicfluidsstoptheactionofcertainenzymes,calledcholinesterases,inthebody.Therearenoreportsofpeopleswallowingorbreathingthetypesofhydraulicfluidsthatcausetheseeffects.Whencertaintypesofhydraulicfluidswereputintotheeyesofanimalsorallowedtotouchtheskinofpeopleoranimalsforshortperiodsoftime,rednessandswellingoccurred.Itisnotknownwhetherhydraulicfluidscancausebirthdefectsorreproductiveeffects.IsthereamedicaltesttoshowwhetherIvebeenexposedtohydraulicfluids?Hydraulicfluidscantbemeasuredinblood,urine,orfeces,butcertainchemicalsinthehydraulicfluidscanbemeasured.Someofthehydraulicfluidsstoptheactivityofcertainenzymes,calledcholinesterases,inbloodandthisactivitycanbemeasured.However,manyotherchemicalsalsocausethiseffect.Thistestisntavailableatmostdoctorsoffices,butcanbedoneatspeciallaboratoriesthathavetherightequipment.Hasthefederalgovernmentmaderecommendationstoprotecthumanhealth?Therearenofederalgovernmentrecommendationstoprotecthumansfromthehealtheffectsofthemajorhydraulicfluids.However,mineraloil,themajorchemicalingredientofonetypeofhydraulicfluid,ispartofthepetroleumdistillateclassofchemicalsandthereareregulationsforthesechemicals.TheOccupationalSafetyandHealthAdministration(OSHA)hassetanexposurelimitof2,000milligrampercubicmeter(mg/m)petroleumdistillatesforan8-hourworkday,40-hourworkweek.TheNationalInstituteforOccupationalSafetyandHealth(NIOSH)recommendsanexposurelimitof350mg/mpetroleumdistillatesfora10-hourworkday,40-hourworkweek.GlossaryAdditive:Substanceaddedtoanotherinsmallamountstoimproveitsproperties.CAS:ChemicalAbstractsService.Carcinogenicity:Abilitytocausecancer.PetroleumDistillate:Achemicalfractionofpetroleum徐州工程学院毕业设计（论文）4中文译文液压油液压油是一种作为动力传输使用很广泛的液体。流体类型包括合成化合物，矿物油，水和水基混合物。流体在机器及设备，包括刹车，动力转向系统，传输，推土机，挖掘机，垃圾车及工业碎纸机中都出现过。液压系统在飞机飞行控制系统中是非常普遍的。如果液压油用低压缩的话，像上述液压系统工作是最有效的，。在液压系统中，因为工业液压系统在数百至数千防扩散安全倡议及温度达到数百摄氏度的运作，造成严重受伤和死亡的结果，必须时刻注意。耐火是液压油使用的需要。液压系统在飞机的开始与制动系统中使用几乎是肯定的。引文需要在20世纪中