facility n. ［pl.］设备；便利，容易记忆技巧对比近义词记忆：convenience, advantage, means, ease, easiness, effortlessness, smoothness, fluency, proficiency【短语搭配】athletic facilities 体育设备/recreational facilities 娱乐设施/communication facilities 通讯设备/lodge and eating facilities 食宿条件The computerized phone has a call-back facility. 计算机化的电话有回叫装置。
【辨析】facility 指能提供方便或服务的设备；instrument 意为“仪器，器具”，尤指医疗器械和高科技仪器，如：surgical instruments 外科器械；utensil 指有特殊用途的工具或容器，如：cooking utensils 厨房用具；equipment 指实用或技术的装备、设备，如：video equipment 录像设备，fire-fighting equipment 消防设备。
apparatus,appliance,equipment,facility,instrument都含有一定的"器具"之意apparatus 指"一套仪器,一套器械,装置"appliance 通常指需要动力才能操作的家用电器和装置等equipment 指"设备,装备"facility (pl.)"设备,设施",只是工作生活便利的工具和环境instrument 指精密的或科学的和艺术上使用的器具等1.Today,housework has been made much easier by electrical ___.A.facilitiesB.appliancesC.instrumentsD.apparatus2.The complete ___ of the new library will take another year.A.apparatusB.facilityC.instrumentD.equipment3.The school offer us the ___ for study.A.facilitiesB.appliancesC.instrumentsD.apparatus4.This hospital imported many surgical ___ from abroad.A.facilitiesB.appliancesC.instrumentsD.apparatus5.The Browns are always very cold in winter because they have not a heating ___.A.facilitiesB.appliancesC.instrumentsD.apparatus1.Today,housework has been made much easier by electrical __B__.现在,家用电器使得家务活轻松多了.A.facilitiesB.appliancesC.instrumentsD.apparatus2.The complete __D___ of the new library will take another year.新图书馆的全套设备还要花一年时间才能完成.A.apparatusB.facilityC.instrumentD.equipment3.The school offer us the __A__ for study.学校为我们提供了便利学习的设施.A.facilitiesB.appliancesC.instrumentsD.apparatus4.This hospital imported many surgical __C__ from abroad.医院从国外进口了许多外科器械.A.facilitiesB.appliancesC.instrumentsD.apparatus5.The Browns are always very cold in winter because they have not a heating __D__.布朗一家每到冬天就很冷,因为他们没有暖气设备.A.facilitiesB.appliancesC.instrumentsD.apparatus1.apparatus：既可指某种具体的由许多不同零件构成的复杂的仪器、装置或器械，又可指它们的总称。
Mechanical Vibrations（机械振动）Mechanical vibrations are the oscillatory motions, either continuous or transient, of objects and structures. In some instances they are purposefuIandintegraltothedesignofamachineasinapneumaticdrillorareciprocat ingengine.Inmostinstances,however,theyareincidentaloraccidentalandmayimp air thenormalfunctioning ofastructureorinstrument. Suchvibrationsenterintoallaspectsofthemechanicalworldandarethereforeofint eresttosomeextentinallfieldsofengineeringscienceandphysics.Aknowledgeofthefundamentalsofmechanical vibrationsisindispensabletopractitionersofthesevariedtechnologies. EffectsofVibrationsinMechanicalSystems Thereareanumberofweightyreas onsfor thewidespreadinterestinthefundamentalsandpracticalaspects ofmechanicalvibrations. Onesuchreasonisthepossibilityofundesirableeffectsbyvibrationsonmechanica lsystems.Anygeneralmechanicalsystem,forexample,wholebuildings,instrument sonthebenchinthelaboratory,complexmechanicaltoolsonthefloorofaworkshop,tr ansportvehiclesorahumanbeingmayberepresentedbysomepatternorformofinter connectedmass/spring/damperelements.Sincemostdrivingforcesƒt maybede emedtohaveharmoniccomponents，thepossibility ofexcitingresonancewithintheover-allsystemisgreat.Ifaresonanceisnotdamped, thedisplacement ofthemassandhencethestretching ofthespringelementwilltendtowardsinfinity.Thespringcomponentwillfractureandf orthisreasonundampedresonancesmustbe avoidedfortheprotection ofequipmentandinstruments.Thisappliesalsowhenthehumanbodyis part oftheover-allsystemwhichmightexperiencethedamagingresonance.Long-termexposure ofamechanicalsystemtovibrations offrequenciesawayfromresonance canalsocausedamagethroughthemechanismoffatigue.Thus,ifamechanicalcomponentsuchasaspringissubjectedtorepetitiveorcyclicalapplications ofstresslevelsmuchlowerthantheultimatestrength,itwillfractureafteralargenumb er ofrepetitions ofthisstress.Indeed,ifthenumberofcyclesofstressisincreased,theamplitudeofthe stressneededeventuallytocausefracturebecomeslower. Theunderlyingmechanisminfatigueappearstobethegradualunzipping ofintermolecularbondsstartingfromadefectorweaknessinthemolecularstructure. Anotherundesirableeffectofvibrationsisthefactthattheycanimpairthenormalfun ctioningofinstruments,Thus,iftherearevibrationswithinanelectronmicroscopewhichmag nifies by over×104,ablurredimagecanresult.VibrationsinamicrotomecanresuItincuts ofdifferentthicknesses.Likewise，manydevicesinfineengineeringandopticscannottolerate excessivevibrations.Electricalconnectionscanbeundonebyvibrations. Unwantedvibrationsinasystem，furthermore，indicateinefficiency. Energyis wastedinexcitingthevibrationsinstead ofbeingeffectivelydirectedtothework ofthesystem.Anotherundesirableside-effect ofvibratingstructuresisthegeneration ofaudiblenoise.Suchnoisecanbepsychologicallyannoyingtohumanbeingsworki ngintheenvironmentandrendernormalvoicecommunicationimpossible.Ifextrem e，noisecan irreparablydamagehumanhearing.Themostthorough way ofsuppressingsuchnoiseistoreduceoreliminatethevibrationscausingit. Considerableeffortisdevotedtothemeasurementandexamination ofseismicvibrationsassociatedwithearthquakes．Thesemeasurementsareavita llinkinprovidingadvancewarningand protectiontopopulationsagainstvolcaniceruptionswithwhichareassociatedeartht remors.Anotherarea ofinterestin vibration quantificationistheso-calledplannedorpreventivemaintenanceofequipment,particularlyrotatingmachinery.Asthistype ofmachineryagesand undergoeswear，theassociatedunwantedvibrationstendtobecomegreater.Regularvibrationmeas urementcanprovidein-serviceindices ofthedegeneration ofthemachinery.Repair or replacementcanthenbecarriedoutbeforecatastrophicfailureandatatimeconvenie ntforthefactoryor plant.Thefirststepinany oftheseareasofvibrationscienceistomeasurethevibrations inquestion.MeasurementEquipment Themostgenerallyusedmethodsofmeasuringvibratio nsareelectrical.Thekeycomponentisthevibrationtransducerthat producesanelectricalvoltageorcurrentproportionaltosomequantityinthemech anicalvibration,thedisplacement,velocityoracceleration.Thereafter，avarietyofelectroniccomponentscancarryoutanyof arrange ofstandardelectronicsignalprocessingstepsonthevibrationvoltage.Typicalste psincludeamplification,attenuation，filtering,differentiationandintegration.Thentheprocessedsignalismeasuredwit hameter，displayedonanoscilloscope, recordedonachartrecorderortaperecorderorfurtherprocessedandanalyzedby digitalcomputer.机械振动是物体和结构瞬时或连续的振荡运动。
毕业设计（论文）中文摘要毕业设计（论文）外文摘要目录1 绪论 (2)1.1 课题研究的目的和意义 (4)1.2 本课题国内外研究现状和发展趋势 (5)1.3 本次设计主要完成的工作 (7)2 焊接机器人总体方案确定 (7)2.1 总体传动方案 (7)2.2 驱动方式选择 (7)2.3 各关节传动方案 (8)3 技术参数的确定及详细结构设计 (12)3.1 主要技术参数确定 (12)3.2 传动结构设计 (16)3.3 详细结构设计 (18)4 零部件的计算及校核 (26)4.1 直齿圆锥齿轮的校核计算 (26)4.2 直齿圆柱齿轮的校核计算 (29)4.3 轴的校核计算 (36)结论 (38)参考文献 (39)致谢 (40)1 绪论“机器人”一词最早出现于1920年捷克作家Karel Capek的剧本《罗萨姆的万能机器人》中。
1984年，ISO（国际标准化组织）采纳了美国机器人协会（RIA）的建议，给机器人下了个定义，即“机器人是一种可反复编程和多功能的用来搬运材料、零件、工具的操作工具，为了执行不同任务而具有可改变和可编程的动作的专门系统（A reprogrammable and multifunctional manipulator ,devised for the transport of materials,parts,tools or specialized systems,with varied and programmed movements,with the aim of carring out varied tasks）”。
[1]工业机器人作为现代制造技术发展重要标志之一和新兴技术产业，已为世人所认同，并正对现代高技术产业各领域以至人们的生活产生重要影响。
机器人是柔性自动化的集中体现。
自从美国推出世界上第一台工业机器人Unimate以来，机器人技术的研究和发展过程经历了三个阶段：（1）第一代是示教再现型的机器人，这类机器人不具备外界信息反馈能力，很难适应变化的环境。
