汽車主減速器外文文獻(xiàn)翻譯、中英文翻譯、外文翻譯,汽車,減速器,外文,文獻(xiàn),翻譯,中英文 AUTOMOTIWE?FINAL?DRIVE FINAL?DRIVE ???A?final?drive?is?that?part?of?a?power?transmission?system?between?the?drive?shaft?and?the?differential.?Its?function??is??to??change??the??direction??of??the??power?transmitted??by??the??drive??shaft?through??90??degrees??to??the?driving??axles At??the??same? time it??provides??a?fixed?reduction?between?the?speed?of?the?drive?shaft?and? the?axle?driving?the?wheels.? ???The??reduction??or??gear??ratio??of??the??final??drive??is?determined?by?dividing?the?number?of?teeth?on?the?ring?gear??by??the??number??of??teeth??on??the??pinion??gear .In?passenger??vehicles,??this??speed??reduction??varies??from?about?3:1?to?5:1.?In?trucks?it?varies?from?about?5:1?to?11:1.?To?calculate?rear?axle?ratio,?count?the?number?of?teeth?on?each?gear.?Then?divide?the?number?of?pinion?teeth into?the?number?of?ring?gear?teeth.?For?example,?if?the?pinion?gear?has?10?teeth?and?the?ring?gear?has?30?30?divided??by??10,??the??rear??axle??ratio??would??be??3:1.?Manufacturers?install?a?rear?axle?ratio?that?provides?a?compromise??between??performance??and??economy .The?average?passenger?car?ratio?is?3.50:1.? ???The?higher?axle ratio,?4.11:1?for?instance,?would?increase acceleration??and??pulling??power??but??would?decrease?fuel?economy.?The?engine?would?have?to?run?at?a?higher?rpm?to?maintain?an?equal?cruising?speed? ???The lower axle ratio?3:1, would reduce?acceleration?and?pulling?power?but?would?increase?fuel?mile age. The??engine??would??run??at??a??lower??rpm??while?maintaining?the?same?speed? ???The?major?components?of?the??final??drive??include?the??pinion?? gear,??connected??to??the??drive??shaft,??and??a?bevel?gear?or?ring? gear?that?is?bolted?or?riveted?to?the?differential??carrier. To maintain??accurate and?proper?alignment?and?tooth?contact,?the?ring??gear??and?differential??assembly??are??mounted??in??bearings .The?bevel?drive?pinion?is?supported?by?two?tapered?roller bearings, mounted in the differential carrier ?This?pinion?shaft?is?straddle??mounted meaning??that??a?bearing?is?located?on?each?side?of?the?pinion?shaft?teeth.?Oil?seals?prevent?the?loss?of?lubricant??from??the??housing?where?the?pinion?shaft?and?axle?shafts?protrude.?As?a?mechanic,?you?will?encounter?the?final?drive?gears?in?the?spiral bevel?and?hypoid?design.?Spiral?Bevel?Gear?? ???Spiral bevel gears?have?curved?gear?teeth?with?the?pinion?and?ring?gear?on?the?same?center?line.?This?type?of??final??drive??is??used??extensively??in??truck??and?occasionally?in?older?automobiles.?This?design?allows?for?constant?contact?between?the?ring?gear?and?pinion.?It?also?necessitates?the?use?of?heavy?grade?lubricants Hypoid?Gear. ???The?hypoid?gear?final?drive?is?an?improvement?or?variation?of?the? spiral?bevel?design?and?is?commonly?used?in?light?and?medium?trucks?and?all?domestic?rear-?wheel?drive?automobiles.?Hypoid?gears?have?replaced?spiral?bevel?gears?because?they?lower?the?hump?in?the??floor??of??the??vehicle??and??improve??gear-meshing??action.?As?you?can?see?in?figure?5-13,?the?pinion?meshes?with?the?ring?gear?below?the?center?line?and?is?at?a?slight?angle?less?than?90?degrees??? ????Figure?5-13.?Types?of?final?drives???This?angle?and?the?use?of?heavier??larger??teeth??permit??an??increased??amount??of?power?to?be?transmitted?while?the?size?of?the?ring?gear?and?housing?remain constant.?The?tooth?design?is?similar?to?the?spiral?bevel?but?includes?some?of?the?characteristics?of?the?worm?gear.?This?permits?the?reduced?drive?angle.?The?hypoid?gear?teeth?have?a?more?pronounced?curve?and?steeper?angle,?resulting?in?larger?tooth?areas?and?more?teeth?to?be?in contact?at?the?same?time.?With?more?than?one?gear?tooth?in??contact,??a??hypoid??design??increases??gear??life??and?reduces??gear??noise .The??wiping??action??of??the??teeth?causes??heavy??tooth??pressure??that??requires??the??use??of?heavy??grade??lubricants.?Double-Reduction?Final??Drive.?? ???In?the?final?drives?shown?in?figure?5-13,?there?is?a single fixed gear reduction?This is the only gear?reduction?in?most??automobiles??and??light-??and??some?medium-duty??trucks??between??the??drive??shaft??and??the?wheels.? ???Double-reduction?final?drives?are?used?for?heavy-?duty?trucks.?With?this?arrangement?fig.?5-14?it?is?not?necessary?to?have?a?large?ring?gear?to?get?the?necessary?gear??reduction .The??first??gear?reduction??is??obtained?through?a?pinion?and?ring?gear?as?the?single?fixed?gear?reduction?final?drive.?Referring?to?figure?5-14,?notice?that?the??secondary??pinion??is??mounted??on??the??primary?ring?gear?shaft.?The?second?gear?reduction?is?the?result?of?the?secondary?pinion?which?is?rigidly?attached?to?the?primary?ring?gear,?driving?a?large?helical?gear?which?is?attached to the differential case?Double-reduction?final?drives?may?be?found?on?military?design?vehicles,?such?as?the?5-ton?truck.?Many?commercially?designed?vehicles?of?this?size? use?a?single-?or?double-reduction?final??drive??with??provisions??for??two??speeds??to??be?incorporated?. ????Figure?5-14.? Double-reduction?final?drive?Two-Speed?Final?Drive??The?two-speed?or?dual-ratio?final?drive?is?used?to? Supplement the gearing of the other drivetrain?components?and?is?used?in?vehicles?with?a?single?drive?axle??fig5-15The??operator??can??select??the??range??or?speed?of?this?axle?with?a?button?on?the?shifting?lever?of?the?transmission?or?by?a?lever?through?linkage.? ???The??two-speed??final??drive??doubles??the??number??of?gear?ratios?available?for?driving?the?vehicle?under?various load and road conditions?For example, a?vehicle with at wo-speed unit and a five-speed?transmission ,ten different forward speed are?available.?This?unit provides?a?gear?ratio?high?enough?to?permit?pulling?a?heavy?load?up?steep?grades?and?a?low??ratio??to??permit??the??vehicle??to??run??at??high??speeds?with?a?light?load?or?no?load?. ???The?conventional?spiral?bevel?pinion?and?ring?gear?drives?the?two-speed?unit,?but?a?planetary?gear?train?is?placed?between?the?differential?drive?ring?gear?and?the?differential??case .The??internal??gear??of??the??planetary?gear?train?is?bolted?rigidly?to?the?bevel?drive?gear.?A?ring?on?which?the?planetary?gears?are?pivoted?is?bolted?to??the??differential??case A??member,??consisting??of??the?sun??gear??and??a??dog??clutch,??slides??on??one??of??the??axle?shafts??and??is??controlled??through??a??button??or??lever?accessible?to?the?operator.? ???When?in?high?range,?the?sun?gear?meshes?with?the?internal?teeth?on?the?ring?carrying?the?planetary?gears?and??disengages?the??dog??clutch??from??the??left??bearing?adjusting?ring,?which?is?rigidly?held?in?the?differential?carrier .In??this??position,??the??planetary?gear?train?is?locked?together.?There?is?no?relative?motion?between?the?differential?case?and?the?gears?in?the?planetary?drive?train .The??differential??case??is??driven??directly??by??the?differential?ring?gear,?the?same?as?in?the?conventional?single?fixed?gear?final?drive.? ???When?shifted?into?low?range,?the?sun?gear?is?slid?out?of?mesh?with? the?ring?carrying?the?planetary?gears.?The?dog?clutch?makes?a?rigid? connection?with?the?left?bearing?adjusting?ring.?Because?the?sun?gear?is?integral?with??the??dog??clutch,??it??is?also??locked??to?the??bearing?adjusting??rings??and??remains??stationary .The??internal?gear?rotates?the?planetary?gears?around?the?stationary?sun?gear,?and?the?differential?case?is?driven?by?the?ring?on?which?the?planetary?gears?are?pivoted.?This?action?produces?the?gear?reduction,?or?low?speed, of?the?axle?DIFFERENTIALACTION? ???The?rear?wheels?of?a?vehicle?do?not?always?turn?at?the?same?speed.?When?the?vehicle?is?turning?or?when?tire??diameters??differ??slightly,??the??rear??wheels??must?rotate?at?different?speeds???If?there?were?a?solid?connection?between?each?axle?and?the?differential?case,?the?tires?would?tend?to?slide,?squeal,?and?wear??whenever??the??operator??turned??the?steering??wheel??of??the??vehicle A??differential?is??designed?to?prevent?this?problem Driving?Straight?Ahead?. ???When?a?vehicle?is?driving?straight?ahead,?the?ring?gear,?the?differential?case,?the?differential?pinion?gears,?and?the differential?side?gears?turn?as?a?unit.?The?two?differential?pinion?gears?do?NOT?rotate?on?the?pinion?shaft,?because?they?exert equal?force?on?the?side?gears.?As?a?result,?the?side?gears?turn?at?the?same?speed?as?the?ring?gear,?causing?both?rear?wheels?to?turn?at?the?same?speed Turning?Corners.? ???When?the?vehicle?begins?to?round?a?curve,?the?differential?pinion?gears?rotate?on?the?pinion?shaft. This?occurs?because?the?pinion?gears?must?walk?around?the?slower??turning??differential?side gear. Therefore,?the pinion?gears?carry?additional??rotary??motion??to??the??faster?turning?outer?wheel?on?the?turn???Differential?speed?is?considered?to?be?100?percent.?The??rotating??action??of??the??pinion??gears??carries??90?percent?of?this?speed?to?the?slowing?mover?inner?wheel?and?sends?110?percent?of?the?speed?to?the?faster?rotating?outer?wheel.?This?action?allows?the?vehicle?to?make?the?turn without?sliding?or?squealing?the?wheels Figure?5-15.?Two?speed?final?drive. ???? 汽車主減速器 ? 主減速器是在傳動軸和差速器之間的一個動力傳動系統(tǒng)的組成部分。它的作用是通過90°傳動軸改變傳給驅(qū)動軸的動力傳遞方向。同時,它提供了一個固定的減速,該值介于傳動軸和驅(qū)動輪軸的速度之間。主減速器的減速和齒輪傳動比取決于環(huán)形齒輪齒數(shù)和小齒輪齒數(shù)。 客車的減速在3:1到5:1之間,卡車是在5:1到11:1之間。計算后軸傳動比要數(shù)每個齒輪上的齒數(shù)。然后把小齒輪的齒數(shù)插入環(huán)形齒輪的齒數(shù)。例如,如果小齒輪有10齒,齒圈有3030除以10,后軸比率將3:1。生產(chǎn)廠家在安裝后軸傳動比時要考慮到性能和費(fèi)用之間的協(xié)調(diào)?？蛙嚻骄谋嚷适?.50:1更高軸比,例如4.11:1,將增加加速度和動力但會降低燃油經(jīng)濟(jì)性。發(fā)動機(jī)將不得不突然進(jìn)攻一個更高轉(zhuǎn)速保持一個能與之匹敵的速度。較低級軸比如3:1,這將減少加速度和拉動力但是將會增加燃油里程。發(fā)動機(jī)將突然進(jìn)攻一個降低轉(zhuǎn)速而維持同一速度。 主減速器的主要元件包括連接到傳動軸上的小齒輪,和一個被鉚釘固定在差速器殼上的斜齒輪或者是圓柱齒輪。為了保持輪齒之間準(zhǔn)確,正確的接觸,齒圈,差動總成被安裝在一定的方位。主動小錐齒輪由二對圓錐滾子軸承支撐,安裝在差速器上。這個小齒輪軸跨式組合安裝。意味著那是一個能被定位在每個小齒輪齒側(cè)的軸齒。油封是為了防止?jié)櫥瑒?小齒輪軸,軸凸出的部分泄漏弧齒錐齒輪具有彎曲的輪齒的弧齒錐齒輪同小齒輪,齒圈在同一中心線。這種主減速器形式被廣泛使用在卡車上。這個設(shè)計允許環(huán)形齒和小齒輪之間建立不斷地聯(lián)系。它也因此有必要用高等級滑潤劑。雙曲面齒輪減速器是一個改進(jìn)或變異的盤旋斜角設(shè)計,常用在輕型和中型卡車以及所有國內(nèi)的四輪驅(qū)動汽車上。雙曲面齒輪已經(jīng)取代了弧齒錐齒輪,因為他們降低了汽車底板上的凸起,改善輪齒嚙合行動。小齒輪軸線在中心線的下,在一個輕微角度少于90°。這個角度和用的(大)的輪齒可以保證被傳遞的功率增加同時保持環(huán)形齒的大小和容積不變。這種齒型設(shè)計類似蝸輪的特征。這個保證驅(qū)動器角的減小。雙曲線齒輪輪齒有一個更顯著的彎曲和陡峭的,導(dǎo)致了在大齒輪輪齒地區(qū)更多的輪齒在同時接觸。在不止一個輪齒在同時接觸的情況下,一個雙曲線設(shè)計能夠增加齒輪的壽命和減少齒輪音。輪齒的縱向滑動會引起很大的壓力,所以要使用高等級的潤滑油。?雙級主減速器,有一個獨(dú)立的固定減速齒輪。這個獨(dú)一無二的減速齒輪常用在大多數(shù)汽車和輕型和中型卡車的傳動軸和車輪之間。雙級主減速器主要被用在重型卡車上。有了這種安排我們就沒必要用一個大直徑的環(huán)形齒輪來使其獲得必要的齒輪減速。第一級齒輪減速是通過一個小齒輪,齒圈作為單固定齒輪減速來實現(xiàn)的主減速器。我們注意到那個次要小齒輪被安裝在主環(huán)形齒輪軸上。第二級齒輪減速是通過被安裝在主環(huán)形齒輪軸上的次要小齒輪驅(qū)動被附屬在差動器里面的一個大的螺旋齒輪實現(xiàn)的。雙級主減速器可在軍用汽車上發(fā)現(xiàn),例如5噸卡車上。許多這種尺寸的商用汽車設(shè)計使用單級或雙級主減速器同規(guī)定的雙速結(jié)合在一起。?雙速主減速器雙速或者是兩傳動比的主減速器常常被用來補(bǔ)充另一個傳動元件的齒輪,常用在單驅(qū)動軸的汽車上。操作者選擇這個軸的范圍或者是速度可以通過一個按鍵安裝在傳輸?shù)淖兯贄U上或者是一個連鎖的杠桿。雙速減速器擁有兩個齒輪比來驅(qū)動汽車以適用多種多樣的負(fù)荷和道路狀況。例如一輛汽車有一個雙速單元,一個五速傳輸,那么就有十種不同的前進(jìn)速度可供使用。這個單元提供一個足夠高的齒輪齒數(shù)比來保證可以重負(fù)荷行駛,和一個低的比率以允許車輛在輕載或者是空載的情況下以高速來運(yùn)行。 常規(guī)螺旋小傘齒輪,齒圈驅(qū)動雙速單位,但一個行星齒輪系被放置在差速器傳動齒輪和差速器殼之間。內(nèi)齒輪行星齒輪系被用螺絲定在硬性斜角傳動齒輪。有一個環(huán),在這個環(huán)上行星齒輪是回轉(zhuǎn)的,這個環(huán)被釘在差速器殼上。一個成員,它的組成包括太陽輪和一個爪形離合器,滑動在其中的一個半軸上,通過一個按或者是連接到操作者那里的杠桿被控制。當(dāng)在高的范圍,相嚙合的太陽齒輪同在環(huán)上的內(nèi)齒攜帶行星齒輪,從左邊的調(diào)整環(huán)上脫離接觸爪形離合器,這個環(huán)硬性固定在差速器殼上。在這個位置上,星系齒輪系被鎖在一起。在差速器殼和在行傳動軸里的齒輪之間沒有相對運(yùn)動。差速器殼由差速器環(huán)齒輪直接驅(qū)動,在常規(guī)的單級主減速器也是同樣的。當(dāng)在轉(zhuǎn)換到低的范圍,太陽齒輪從嚙合的狀態(tài)滑離,和調(diào)整環(huán)一起驅(qū)動行星齒輪爪形離合器和左邊的調(diào)整環(huán)構(gòu)成了一個剛性連接。因為太陽輪也是爪形離合器的一部分,它業(yè)被鎖在調(diào)整環(huán)上,保持靜止。內(nèi)齒輪使行星齒輪繞著靜止的太陽輪旋轉(zhuǎn)。差動器外殼通過行星齒輪被安裝在樞軸上的環(huán)來驅(qū)動。這個動作將產(chǎn)生齒輪減速或者是低速的軸。一輛汽車的后輪不是總是用同一種速度在行駛。當(dāng)汽車在轉(zhuǎn)彎或者是當(dāng)輪胎直徑不同,汽車的后輪們必須以不同的速度運(yùn)轉(zhuǎn)。如果在每個軸和差速器殼之間都有一個固體連接,那么輪胎將傾向于滑動、發(fā)出尖銳的噪聲、以及每當(dāng)操作者轉(zhuǎn)動方向盤的時候磨損。一個差速器就被設(shè)計用來防止這樣的問題。當(dāng)汽車在直線行駛時,齒圈,差速器殼,差速器小齒輪和差速器邊緣齒輪像一個單元一樣運(yùn)轉(zhuǎn)。兩個差速器小齒輪不在一個小齒輪軸上運(yùn)轉(zhuǎn),所以對變齒輪施加的力相同。結(jié)果,兩半軸齒輪與環(huán)形齒輪同一速度運(yùn)轉(zhuǎn),導(dǎo)致兩個車輪用同一速度運(yùn)轉(zhuǎn)。轉(zhuǎn)彎當(dāng)車輛按曲線行駛,差動齒輪旋轉(zhuǎn)在小齒輪軸。發(fā)生這種情況四因為小齒輪齒輪必須繞著慢轉(zhuǎn)差速器側(cè)齒輪旋轉(zhuǎn)。因此,在轉(zhuǎn)彎時,小齒輪會帶動差速器旋轉(zhuǎn)運(yùn)動來使外轉(zhuǎn)向輪運(yùn)動速度快。?差動的速度被認(rèn)為是百分之百。小齒輪的旋轉(zhuǎn)運(yùn)動將會把百分之九十的這個速度帶該運(yùn)動緩慢的內(nèi)輪,把百分之一百一的速度傳遞給運(yùn)動較快的外輪。這個動作會使汽車在轉(zhuǎn)彎的時候無滑動或者是這輪無噪聲。 8