齒輪機(jī)構(gòu)中英文翻譯、外文文獻(xiàn)翻譯

翻譯部分英文原文GEARMECHANISMSGEARMECHANISMSAREUSEDFORTRANSMITTINGMOTIONANDPOWERFROMONESHAFTTOANOTHERBYMEANSOFTHEPOSITIVECONTACTOFSUCCESSIVELYENGAGINGTEETHINABOUT2,600BC,CHINESEAREKNOWNTOHAVEUSEDACHARIOTINCORPORATINGACOMPLEXSERIESOFGEARSLIKETHOSEILLUSTRATEDINFIG27ARISTOTLE,INTHEFOURTHCENTURYBCWROTEOFGEARSASIFTHEYWERECOMMONPLACEINTHEFIFTEENTHCENTURYAD,LEONARDODAVINCIDESIGNEDAMULTITUDEOFDEVICESINCORPORATINGMANYKINDSOFGEARSINCOMPARISONWITHBELTANDCHAINDRIVES,GEARDRIVESAREMORECOMPACT,CANOPERATEATHIGHSPEEDS,ANDCANBEUSEDWHEREPRECISETIMINGISDESIREDTHETRANSMISSIONEFFICIENCYOFGEARSISASHIGHAS98PERCENTONTHEOTHERHAND,GEARSAREUSUALLYMORECOSTLYANDREQUIREMOREATTENTIONTOLUBRICATION,CLEANLINESS,SHAFTALIGNMENT,ETC,ANDUSUALLYOPERATEINACLOSEDCASEWITHPROVISIONFORPROPERLUBRICATIONGEARMECHANISMSCANBEDIVIDEDINTOPLANARGEARMECHANISMSANDSPATIALGEARMECHANISMSPLANARGEARMECHANISMSAREUSEDTOTRANSMITMOTIONANDSPATIALGEARMECHANISMSPLANARGEARMECHANISMSAREUSEDTOTRANSMITMOTIONANDPOWERBETWEENPARALLELSHAFTS,ANDSPATIALGEARMECHANISMSBETWEENNONPARALLELSHAFTSTYPESOFGEARS1SPURGEARSTHESPURGEARHASACYLINDRICALPITCHSURFACEANDHASSTRAIGHTTEETHPARALLELTOITSAXISASSHOWNINFIG28THEYAREUSEDTOTRANSMITMOTIONANDPOWERBETWEENPARALLELSHAFTSTHETOOTHSURFACESOFSPURGEARSCONTACTONASTRAIGHTLINEPARALLELTOTHEAXESOFGEARSTHISIMPLIESTHATTOOTHPROFILESGOINTOANDOUTOFCONTACTALONGTHEWHOLEFACEWIDTHATTHESAMETIMETHISWILLTHEREFORERESULTINTHESUDDENLOADINGANDSUDDENUNLOADINGONTEETHASPROFILESGOINTOANDOUTOFCONTACTASARESULT,VIBRATIONANDNOISEAREPRODUCED2HELICALGEARSTHESEGEARSHAVETHEIRTOOTHELEMENTSATANANGLEORHELIXTOTHEAXISOFTHEGEARFIG29THETOOTHSURFACESOFTWOENGAGINGHELICALGEARSINNPLANARGEARMECHANISMSCONTACTONASTRAIGHTLINEINCLINEDTOTHEAXESOFTHEGEARSTHELENGTHOFTHECONTACTLINECHANGESGRADUALLYFROMZEROTOMAXIMUMANDTHENFROMMAXIMUMTOZEROTHELOADINGANDUNLOADINGOFTHETEETHBECOMEGRADUALANDSMOOTHHELICALGEARSMAYBEUSEDTOTRANSMITMOTIONANDPOWERBETWEENPARALLELSHAFTSFIG29AORSHAFTSATANANGLETOEACHOTHERFIG29DAHERRINGBONEGEARFIG29CISEQUIVALENTTOARIGHTHANDANDALEFTHANDHELICALGEARPLACEDSIDEBYSIDEBECAUSEOFTHEANGLEOFTHETOOTH,HELICALGEARSCREATECONSIDERABLESIDETHRUSTONTHESHAFTAHERRINGBONEGEARCORRECTSTHISTHRUSTBYNEUTRALIZINGIT,ALLOWINGTHEUSEOFASMALLTHRUSTBEARINGINSTEADOFALARGEONEANDPERHAPSELIMINATINGONEALTOGETHEROFTENACENTRALGROOVEISMADEAROUNDTHEGEARFOREASEINMACHINING3BEVELGARSTHETEETHOFABEVELGEARAREDISTRIBUTEDONTHEFRUSTUMOFACONETHECORRESPONDINGPITCHCYLINDERINCYLINDRICALGEARSBECOMESPITCHCONETHEDIMENSIONSOFTEETHONDIFFERENTTRANSVERSEPLANESAREDIFFERENTFORCONVENIENCE,PARAMETERSANDDIMENSIONSATTHELARGEENDARETAKENTOBESTANDARDVALUESBEVELGEARSAREUSEDTOCONNECTSHAFTSWHICHARENOTPARALLELTOEACHOTHERUSUALLYTHESHAFTSARE90DEGTOEACHOTHER,BUTMAYBEMOREORLESSTHAN90DEGTHETWOMATINGGEARSMAYHAVETHESAMENUMBEROFTEETHFORTHEPURPOSEOFCHANGINGDIRECTIONOFMOTIONONLY,ORTHEYMAYHAVEADIFFERENTNUMBEROFTEETHFORTHEPURPOSEOFCHANGINGBOTHSPEEDANDDIRECTIONTHETOOTHELEMENTSMAYBESTRAIGHTORSPIRAL,SOTHATWEHAVEPLAINANDSPIRALBEVELGEARSHYPOIDCOMESFROMTHEWORDHYPERBOLOIDANDINDICATESTHESURFACEONWHICHTHETOOTHFACELIESHYPOIDGEARSARESIMILARTOBEVELGEARS,BUTTHETWOSHAFTSDONOTINTERSECTTHETEETHARECURVED,ANDBECAUSEOFTHENONINTERSECTIONOFTHESHAFTS,BEARINGSCANBEPLACEDONEACHSIDEOFEACHGEARTHEPRINCIPALUSEOFTHIDTYPEOFGEARISINAUTOMOBILEREARENDSFORTHEPURPOSEOFLOWERINGTHEDRIVESHAFT,ANDTHUSTHECARFLOOR4WORMANDWORMGEARSWORMGEARDRIVESAREUSEDTOTRANSMITMOTIONANDOWERBETWEENNONINTERSECTINGANDNONPARALLELSHAFTS,USUALLYCROSSINGATARIGHTANGLE,ESPECIALLYWHEREITISDESIREDTOOBTAINHIGHGEARREDUCTIONINALIMITEDSPACEWORMSAREAKINDOFSCREW,USUALLYRIGHTHANDEDFORCONVENIENCEOFCUTTING,ORLEFTHANDEDITNECESSARYACCORDINGTOTHEENVELOPINGTYPE,WORMSCANBEDIVIDEDINTOSINGLEANDDOUBLEENVELOPINGWORMSAREUSUALLYDRIVERSTOREDUCETHESPEEDIFNOTSELFLOCKING,AWORMGEARCANALSOBETHEDRIVERINASOCALLEDBACKDRIVINGMECHANISMTOINCREASETHESPEEDTWOTHINGSCHARACTERIZEWORMGEARINGALARGEVELOCITYRATIOS,ANDBHIGHSLIDINGVELOCITIESTHELATTERMEANSTHATHEATGENERATIONANDPOWERTRANSMISSIONEFFICIENCYAREOFGREATERCONCERNTHANWITHOTHERTYPESOFGEARS5RACKSARACKISAGEARWITHANINFINITERADIUS,ORAGEARWITHITSPERIMETERSTRETCHEDOUTINTOASTRAIGHTLINEITISUSEDTOCHANGERECIPROCATINGMOTIONTOROTARYMOTIONORVICEVERSAALATHERACKANDPINIONISGOODEXAMPLEOFTHISMECHANISMGEOMETRYOFGEARTOOTHTHEBASICREQUIREMENTOFGEARTOOTHGEOMETRYISTHEPROVISIONOFANGULARVELOCITYRATIONSTHATAREEXACTLYCONSTANTOFCOURSE,MANUFACTURINGINACCURACIESANDTOOTHDEFLECTIONSWELLCAUSESLIGHTDEVIATIONSINVELOCITYRATIOBUTACCEPTABLETOOTHPROFILESAREBASEDONTHEORETICALCURVESTHATMEETTHISCRITERIONTHEACTIONOFAPAIROFGEARTEETHSATISFYINGTHISREQUIREMENTISTERMEDCONJUGATEGEARTOOTHACTION,ANDISILLUSTRATEDINFIG212THEBASICLAWOFCONJUGATEGEARTOOTHACTIONSTATESTHATASTHEGEARSROTATE,THECOMMONNORMALTOTHESURFACESATTHEPOINTOFCONTACTMUSTALWAYSINTERSECTTHELINEOFCENTERSATTHESAMEPOINTPCALLEDTHEPITCHPOINTTHELAWOFCONJUGATEGEARTOOTHCANBESATISFIEDBYVARIOUSTOOTHSHAPES,BUTTHEONLYONEOFCURRENTIMPORTANCEISTHEINVOLUTE,OR,MOREPRECISELY,THEINVOLUTEOFTHECIRCLEITSLASTIMPORTANTCOMPETITORWASTHECYCLOIDALSHAPE,USEDINTHEGEARSOFMODELTFORDTRANSMISSIONSANINVOLUTEOFTHECIRCLEISTHECURVEGENERATEDBYANYPOINTONATAUTTHREADASITUNWINDSFROMACIRCLE,CALLEDTHEBASECIRCLETHEGENERATIONOFTWOINVOLUTESISSHOWNINFIG213THEDOTTEDLINESSHOWHOWTHESECOULDCORRESPONDTOTHEOUTERPORTIONOFTHERIGHTSIDESOFADJACENTGEARTEETHCORRESPONDINGLY,INVOLUTESGENERATEDBYUNWINDINGATHREADWRAPPEDCOUNTERCLOCKWISEAROUNDTHEBASECIRCLEWOULDFORTHEOUTERPORTIONSOFTHELEFTSIDESOFTHETEETHNOTETHATATEVERYPOINT,THEINVOLUTEISPERPENDICULARTOTHETAUTTHREAD,SINCETHEINVOLUTEISACIRCULARARCWITHEVERINCREASINGRADIUS,ANDARADIUSISALWAYSPERPENDICULARTOITSCIRCULARARCITISIMPORTANTTONOTETHATANINVOLUTECANBEDEVELOPEDASFARASDESIREDOUTSIDETHEBASECIRCLE,BUTANINVOLUTECANNOTEXISTINSIDEITSBASECIRCLELETUSNOWDEVELOPAMATINGPAIROFINVOLUTEGEARTEETHINTHREESTEPSFRICTIONDRIVE,BELTDRIVE,ANDFINALLY,INVOLUTEGEARTOOTHDRIVEFIGURE214SHOWSTWOPITCHCIRCLESIMAGINETHATTHEYREPRESENTTWOCYLINDERSPRESSEDTOGETHERIFSLIPPAGEDOESNOTOCCUR,ROTATIONOFONECYLINDERPITCHCIRCLEWILLCAUSEROTATIONOFTHEOTHERATANANGULARVELOCITYRATIOINVERSELYPROPORTIONALTOTHEIRDIAMETERSINANYPAIROFMATINGGEARS,THESMALLEROFTHETWOISCALLEDTHEPINIONANDTHELARGERONETHEGEARTHETERM“GEAR”ISUSEDINAGENERALSENSETOINDICATEEITHEROFTHEMEMBERS,ANDALSOINASPECIFICSENSETOINDICATETHELARGEROFTHETWOUSINGSUBSCRIPTSPANDGTODENOTEPINIONANDGEAR,RESPECTIVELYINORDERTOTRANSMITMORETORQUETHANISPOSSIBLEWITHFRICTIONDRIVEALONE,WENOWADDABELTDRIVERUNNINGBETWEENPULLEYSREPRESENTINGTHEBASECIRCLES,ASINFIG215IFTHEPINIONISTURNEDCOUNTERCLOCKWISEAFEWDEGREES,THEBELTWILLCAUSETHEGEARTOROTATEINACCORDANCEWITHCORRECTVELOCITYRATIOINGEARPARLANCE,ANGLEISCALLEDTHEPRESSUREANGLEFROMSIMILARTRIANGLES,THEBASECIRCLESHAVETHESAMERATIOASTHEPITCHTHUS,THEVELOCITYRATIOPROVIDEDBYTHEFRICTIONANDBELTDRIVESARETHESAMEINFIG216THEBELTISCUTATPOINTC,ANDTHETWOENDSAREUSEDTOGENERATEINVOLUTEPROFILESDEANDFGFORTHEPINIONANDGEAR,RESPECTIVELYITSHOULDNOWBECLEARWHYISCALLEDTHEPRESSUREANGLENEGLECTINGSLIDINGFRICTION,THEFORCEOFONEINVOLUTETOOTHPUSHINGAGAINSTTHEOTHERISALWAYSATANANGLEEQUALTOTHEPRESSUREANGLEACOMPARISONOFFIG216ANDFIG212SHOWSTHATTHEINVOLUTEPROFILESDOINDEEDSATISFYTHEFUNDAMENTALLAWOFCONJUGATEGEARTOOTHACTIONINCIDENTALLY,THEINVOLUTEISTHEONLYGEOMETRICPROFILESATISFYINGTHISLAWTHATMAINTAINSACONSTANTPRESSUREANGLEASTHEGEARSROTATENOTEESPECIALLYTHATCONJUGATEINVOLUTEACTIONCANTAKEPLACEONLYOUTSIDEOFBOTHBASECIRCLESNOMENCLATUREOFSPURGEARTHENOMENCLATUREOFSPURGEARFIG217ISMOSTLYAPPLICABLETOALLOTHERTYPEOFGEARSTHEDIAMETEROFEACHOFTHEORIGINALROLLINGCYLINDERSOFTWOMATINGGEARSISCALLEDTHEPITCHDIAMETER,ANDTHECYLINDERSSECTIONALOUTLINEISCALLEDTHEPITCHCIRCLETHEPITCHCIRCLESARETANGENTTOEACHOTHERATPITCHPOINTTHECIRCLEFROMWHICHTHEINVOLUTEISGENERATEDISCALLEDTHEBASECIRCLETHECIRCLEWHERETHETOPSOFTHETEETHLIEISCALLEDTHEDEDENDUMCIRCLESIMILARLY,THECIRCLEWHERETHEROOTSOFTHETEETHLIEISCALLEDTHEDEDENDUMCIRCLEBETWEENTHEADDENDUMCIRCLEANDTHEDEDENDUMCIRCLE,THEREISANIMPORTANTCIRCLEWHICHISCALLEDTHEREFERENCECIRCLEPARAMETERSONTHEREFERENCECIRCLEARESTANDARDIZEDTHEMODULEMOFAGEARISINTRODUCEDONTHEREFERENCECIRCLEASABASICPARAMETER,WHICHISDEFINEDASMP/SIZESOFTHETEETHANDGEARAREPROPORTIONALTOTHEMODULEMTHEADDENDUMISTHERADIALDISTANCEFROMTHEREFERENCECIRCLETOTHEADDENDUMCIRCLETHEDEDENDUMISTHERADIALDISTANCEFROMTHEREFERENCECIRCLETOTHEDEDENDUMCIRCLECLEARANCEISTHEDIFFERENCEBETWEENADDENDUMANDDEDENDUMINMATINGGEARSCLEARANCEPREVENTSBINDINGCAUSEDBYANYPOSSIBLEECCENTRICITYTHECIRCULARPITCHPISTHEDISTANCEBETWEENCORRESPONDINGSIDEOFNEIGHBORINGTEETH,MEASUREDALONGTHEREFERENCECIRCLETHEBASEPITCHISSIMILARTOTHECIRCULARPITCHISMEASUREDALONGTHEBASECIRCLEINSTEADOFALONGTHEREFERENCECIRCLEITCANEASILYBESEENTHATTHEBASERADIUSEQUALSTHEREFERENCERADIUSTIMESTHECOSINEOFTHEPRESSUREANGLESINCE,FORAGIVENANGLE,THERATIOBETWEENANYSUBTENDEDARCANDITSRADIUSISCONSTANT,ITISALSOTRUETHATTHEBASEPITCHEQUALSTHECIRCULARPITCHTIMESTHECOSINEOFTHEPRESSUREANGLETHEPRESSUREANGLEISTHEANGLEBETWEENTHENORMALANDTHECIRCUMFERENTIALVELOCITYOFTHEPOINTONASPECIFICCIRCLETHEPRESSUREANGLEONTHEREFERENCECIRCLEISALSOSTANDARDIZEDITISMOSTCOMMONLY20SOMETIMES15THELINEOFCENTERSISALINEPASSINGTHROUGHTHECENTERSOFTWOMATINGGEARSTHECENTERDISTANCEMEASUREDALONGTHELINEOFCENTERSEQUALSTHESUMOFTHEPITCHRADIIOFPINIONANDGEARTOOTHTHICKNESSISTHEWIDTHOFTHETOOTH,MEASUREDALONGTHEREFERENCECIRCLE,ISALSOREFERREDTOASTOOTHTHICKNESSWIDTHOFSPACEISTHEDISTANCEBETWEENFACINGSIDEOFADJACENTTEETH,MEASUREDALONGTHEREFERENCECIRCLETOOTHTHICKNESSPLUSWIDTHOFSPACEEQUALSTHECIRCULARPITCHBACKLASHISTHEWIDTHOFSPACEMINUSTHETOOTHTHICKNESSFACEWIDTHMEASURESTOOTHWIDTHINANAXIALDIRECTIONTHEFACEOFTHETOOTHISTHEACTIVESURFACEOFTHETOOTHOUTSIDETHEPITCHCYLINDERTHEFLANKOFTHETOOTHISTHEACTIVESURFACEINSIDETHEPITCHCYLINDERTHEFILLETISTHEROUNDEDCORNERATTHEBASEOFTHETOOTHTHEWORKINGDEPTHISTHESUMOFTHEADDENDUMOFAGEARANDTHEADDENDUMOFITSMATINGGEARINORDERTOMATEPROPERLY,GEARSRUNNINGTOGETHERMUSTHAVEATHESAMEMODULEBTHESAMEPRESSUREANGLECTHESAMEADDENDUMANDDEDENDUMTHELASTREQUIREMENTISVALIDFORSTANDARDGEARSONLYROLLINGCONTACTBEARINGSTHEROLLINGCONTACTBEARINGCONSISTSOFNIIERANDOUTERRINGSSEPATATEDBYANUMBEROFROLLINGELEMENTSINTHEFORMOFBALLS,WHICHAREHELDINSEPARATORSORRETAINERS,ANDROLLERBEARINGSHAVEMAINLYCYINNDRICAL,CONICAL,ORBARRELCAGETHENEEDLESARERETAINDEBYINTEGRALFLANGESONTHEOUTERRACE,BEARIGSWITHROLLINGCONTACTHAVENOSKOPSTICKEFFECT,LOWSTATTINGTORQEUANDRUNNINGFRICTION,ANDUNLIKEASINJOURNALBEARINGSTHECOEFFICIENTOFFRICTIONVARIESLITTLEWITHLOADOROPEEDPROBABLYTHEOUTSTANDINGOFAROLLINGCONTANTBEATINGOVERASLIDINGBEARINGISITSLOWSTATTINGFRICTIONTHESRDINARYSLIDINGBEARINGSTARTSFROMRESTWITHPRACTICALLYMETALTOMETALCONTACTANDHASAHIGHCOEFFICIENTOFFRICTIONASCOMPAREDWITHTHATBETWEENROLLINGMEMBERSTHISTEATUREISOFPARTICULARIMPORTANTINTHECASEOFBEATINGSWHCCHVUSTCARRYTHESAMELAODEATTESTASWHENTUNNING,FOREXAMPLELESSTHANONETHIRTIETHASMUCHFORCEISREQUIREDTOSTARTARALIROADFREIGHTCAREQUOPPEDWITHROLLERBEATINGSASWITHPLAINJOURNALBEARINGSHOWEVERMOSTJOURNALBEARINGCANONLYCARRYRELATIVELYLIGHTLOADSWHILESTARTINGANDDONOTBECOMEHEAVILYLOADEDUNTILTHESPEEDISHIGHENOUGHFORAHYDRODYNAMICFILMTOBEBUILTUPATTHISTIMETHEFRICTIONIDTHATINTHELUVRICANT,ANDINAPROPERLYDESIGNEDJOURNALBEARINGTHEVISCOUSFRICTIONWILLBEINTHESAMEORDEROFMAGNITUDEADTHATFORATHATFORAROLLINGCONANCTBEARING中文譯文齒輪機(jī)構(gòu)齒輪機(jī)構(gòu)用來傳遞運(yùn)動和動力，通過連續(xù)嚙合輪齒的正確接觸，從一根軸傳動到另一根軸。大約公元前2600年，中國人就能夠使用一系列戰(zhàn)車而聞名復(fù)雜的齒輪機(jī)構(gòu)而構(gòu)成的。公元前4世紀(jì)，亞里士多德寫的齒輪好象推動的是平凡的。在公元15世紀(jì)，LEONARDODAVINCI設(shè)計(jì)了能與許多種類的齒輪樞結(jié)合的大量裝置。與皮帶和鏈傳動相比較，齒輪傳動裝置更加緊湊，能高速運(yùn)行，也能夠被運(yùn)用在要求準(zhǔn)確定時(shí)的場合。齒輪傳動的傳動效率高達(dá)98。另一方面，齒輪傳動機(jī)構(gòu)成本高，而且要求注意潤滑、清潔度、軸的對中等等，經(jīng)常用在提供準(zhǔn)確箱體潤滑的閉式情況下。齒輪機(jī)構(gòu)能被分為平面齒輪機(jī)構(gòu)和空間齒輪機(jī)構(gòu)。平面齒輪機(jī)構(gòu)被用于傳遞運(yùn)動和動力，而平行軸間的運(yùn)動和動力空間齒輪機(jī)構(gòu)用于傳遞不平行軸間的運(yùn)動和動力。齒輪的分類1、直齒輪直齒輪有節(jié)輪表面和平行于輪的軸線的直齒輪，如圖28所示。它們用于傳遞兩平行軸間的運(yùn)動和動力。兩配合的直接齒面嚙合在一條平行于其軸線的直線上，這意味著整個(gè)齒寬在同一時(shí)刻嚙合脫開，這樣在齒面上導(dǎo)致加載或卸載，當(dāng)齒輪嚙合或脫開時(shí)，結(jié)果推動和噪聲就產(chǎn)生了。、1、斜齒輪這種齒輪的輪齒有一位角度或與其軸線旋轉(zhuǎn)一定角度在平面齒輪機(jī)構(gòu)中相互嚙合，斜齒輪齒面相嚙合于一條傾斜于軸承的直線上，嚙合線的長度從0逐漸變化到最大再從最大變化到0，輪齒的加載和卸載變得平穩(wěn)均勻的運(yùn)動和動力。人字齒輪相當(dāng)于右旋齒輪和左旋齒輪并在一起，因?yàn)檩嘄X存在一定角度，斜齒輪產(chǎn)生相當(dāng)大的軸間推力，人字齒輪通過相互抵消糾正了這一推力，允許其使用以推力軸承代替大推力軸承，或不同推力軸承，為了加工方便經(jīng)常沿著齒輪加工一個(gè)中心槽。、2、傘狀齒輪傘狀齒輪是依據(jù)平截頭圓錐體分配的。圓柱齒輪的節(jié)圓柱成為分圓錐，齒輪的齒的橫剖面的尺寸是不同的。為了方便起見，錐齒輪的大頭端部的參數(shù)和尺寸作為標(biāo)準(zhǔn)值。習(xí)慣上錐齒輪相互作用的軸彼此不是平行的，通常兩軸線彼此成為90度，有時(shí)會比90度或多或少。兩個(gè)相互嚙合的齒輪僅僅為了變向或許有一樣的齒數(shù)，又或者為了改變速度和方向而齒數(shù)不同。錐齒輪可能是直齒的也可能是螺旋形齒輪，以便我們有簡單的和螺旋形的齒輪。準(zhǔn)雙曲面來自于雙曲面和齒面的放置的表面。準(zhǔn)雙曲面的齒輪屬于錐齒輪，但是兩軸不能橫斷，因?yàn)檩S的材料，它的齒是曲線的，軸承可以位于各齒輪的各個(gè)側(cè)面。這種齒輪主要用在汽車后方末端是為了降低傳動軸并且用在汽車踏板處。、3、蝸輪蝸桿齒輪蝸輪傳動慣于傳遞動力和功率，它的軸既不相交也不平行，通常都是垂直的，尤其是要求獲得高的齒輪減速在一定的極限運(yùn)算范圍內(nèi)。蝸桿是螺旋的，通常為了方便起見都是順時(shí)針方向的，如果需要的話也可是左旋方向的。按照類型，可以是單螺旋的也可以是雙螺旋的，螺桿通常用來降低速度的，即使不自動鎖住，螺桿也能夠被驅(qū)動，所以稱作回力驅(qū)動機(jī)構(gòu)，為了提高速度。下面是蝸輪蝸桿傳動裝置的兩個(gè)特點(diǎn)（A）有很高的傳動速度（B）后者意思指和其它種類的齒輪相比中心有高的發(fā)熱性和電力傳輸效率。齒輪輪齒形狀輪齒幾何形狀的基本要求提供一個(gè)準(zhǔn)確不變的角速度，當(dāng)然制造端差和輪齒變形將會在速度比上產(chǎn)生微小的偏差，然而可接受的齒形依據(jù)基于滿足這一判劇的理論曲線得出的。滿足這要求的一對配合齒輪的運(yùn)動被稱為共軛齒輪傳動。如圖212所示，共軛齒輪傳動的基本定律論述為當(dāng)齒輪轉(zhuǎn)動時(shí)，接觸點(diǎn)表面的公法線總是與中心線交于一點(diǎn)P，這點(diǎn)叫節(jié)點(diǎn)。共軛齒輪傳動原則能被各種齒形適應(yīng)，目前最重要的一種是漸開線齒輪更精確地說一個(gè)圓的漸開線（與它相近的重要的競爭者是擺線齒輪，它被用在福特汽車廠模式中）是條曲線，當(dāng)從一個(gè)基圓滿開時(shí)，張緊線上每一點(diǎn)所形成的，兩條漸近線輪齒右外形相對應(yīng)，相應(yīng)地，通過逆時(shí)針方向展開預(yù)先在右基圓上的線所產(chǎn)生的漸開線會形成輪齒左邊的外形，該點(diǎn)在每一點(diǎn)上，漸開線始終垂直于這條張緊線，因?yàn)闈u開線理一條半徑不斷增加的圓弧，值得注意的是漸開線能夠在基圓外部產(chǎn)生并繪制，而不能在基圓里面。用以下三個(gè)步驟研究一對相配合的齒輪摩擦傳動，帶傳動和漸開線齒輪傳動。如圖214所示兩個(gè)節(jié)圓，假設(shè)他們是兩個(gè)壓在一起的圓柱，如果不發(fā)生打滑，一個(gè)圓柱的旋轉(zhuǎn)會引起另一個(gè)圓柱以一定角速