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開(kāi)題報(bào)告
（學(xué)生填表）
學(xué)院：
課題名稱
純電動(dòng)迷你巴士（驅(qū)動(dòng)橋設(shè)計(jì)）
學(xué)生姓名
專業(yè)班級(jí)
課題類型
指導(dǎo)教師
職稱
課題來(lái)源
1. 設(shè)計(jì)（或研究）的依據(jù)與意義
驅(qū)動(dòng)橋位于傳動(dòng)系末端，其基本功用首先是增扭、降速，改變轉(zhuǎn)矩的傳遞方向，即增大由傳動(dòng)軸或直接從變速器傳來(lái)的轉(zhuǎn)矩，并合理的分配給左、右驅(qū)動(dòng)車輪，其次，驅(qū)動(dòng)橋還要承受作用于路面和車架或車廂之間的垂直力、縱向力和橫向力，以及制動(dòng)力矩和反作用力矩。?
汽車驅(qū)動(dòng)橋是汽車的重大總成，承載著汽車的滿載簧荷重及地面經(jīng)車輪、車架及承載式車身經(jīng)懸架給予的鉛垂力、縱向力、橫向力及其力矩，以及沖擊載荷；驅(qū)動(dòng)橋還傳遞著傳動(dòng)系中的最大轉(zhuǎn)矩，橋殼還承受著反作用力矩。汽車驅(qū)動(dòng)橋結(jié)構(gòu)形式和設(shè)計(jì)參數(shù)除對(duì)汽車的可靠性與耐久性有重要影響外，也對(duì)汽車的行駛性能如動(dòng)力性、經(jīng)濟(jì)性、平順性、通過(guò)性、機(jī)動(dòng)性和操動(dòng)穩(wěn)定性等有直接影響。另外，汽車驅(qū)動(dòng)橋在汽車的各種總成中也是涵蓋機(jī)械零件、部件、分總成等的品種最多的大總成。例如，驅(qū)動(dòng)橋包含主減速器、差速器、驅(qū)動(dòng)車輪的傳動(dòng)裝置、橋殼和各種齒輪。由上述可見(jiàn)，汽車的驅(qū)動(dòng)橋設(shè)計(jì)涉及的機(jī)械零部件及元件的品種極為廣泛，對(duì)這些零部件、元件及總成的制造也幾乎要設(shè)計(jì)到所有的現(xiàn)在機(jī)械制造工藝。因此，通過(guò)對(duì)汽車驅(qū)動(dòng)橋的學(xué)習(xí)和設(shè)計(jì)實(shí)踐，可以更好的學(xué)習(xí)并掌握現(xiàn)代設(shè)計(jì)與機(jī)械設(shè)計(jì)的全面知識(shí)和技能。
本論文的研究目的在于通過(guò)對(duì)汽車整體的匹配性設(shè)計(jì)完成驅(qū)動(dòng)橋的主減速器、產(chǎn)俗氣等部件型號(hào)的設(shè)計(jì)與計(jì)算，并完成校核的設(shè)計(jì)計(jì)算。
2. 國(guó)內(nèi)外同類設(shè)計(jì)（或同類研究）的概況綜述
獨(dú)立懸架早期只單純用于轎車上，目前大部分輕型貨車和越野汽車為了提高舒適性也開(kāi)始采用獨(dú)立懸架，同時(shí)一些中型卡車及客車為了提高駕乘的舒適性和行駛性也開(kāi)始采用獨(dú)立懸架，在國(guó)外甚至一些輪式工程機(jī)械如吊車和重型卡車也開(kāi)始采用獨(dú)立懸架。因此對(duì)于獨(dú)立懸架的設(shè)計(jì)技術(shù)，國(guó)內(nèi)外都進(jìn)行了研究，這些研究主要集中在以下幾個(gè)方面：獨(dú)立懸架設(shè)計(jì)方法，獨(dú)立懸架參數(shù)對(duì)汽車行駛平順性的影響；獨(dú)立懸架對(duì)汽車操縱穩(wěn)定性的影響。國(guó)內(nèi)的研究主要表現(xiàn)為：獨(dú)立懸架和轉(zhuǎn)向系的匹配；獨(dú)立懸架與轉(zhuǎn)向橫拉桿長(zhǎng)度和斷開(kāi)點(diǎn)的確定；懸架彈性元件的設(shè)計(jì)分析；獨(dú)立懸架的優(yōu)化設(shè)計(jì)等。國(guó)外除上述研究外還進(jìn)入了微觀領(lǐng)域的研究，如用原子力學(xué)顯微鏡觀察懸架材料內(nèi)部聚合體的電子轉(zhuǎn)化情況，研究懸架作為彈性介質(zhì)的流變特性等，從而使得獨(dú)立懸架向著智能化，輕量化，小型化，通用化方向發(fā)展。同時(shí)由于電子，微機(jī)技術(shù)的發(fā)展，使得獨(dú)立懸架技術(shù)向著半主動(dòng)、主動(dòng)懸架方向發(fā)展。
非獨(dú)立懸架早期廣泛應(yīng)用于除了轎車以外的其它車型中，由于其可靠性和簡(jiǎn)單的特性，現(xiàn)在還被廣泛的用于轎車的后橋，輕型貨車和越野汽車的后橋，重型貨車的前后橋都采用非獨(dú)立懸架。
由于汽車行駛的平順性和操縱穩(wěn)定性的要求，具有安全、智能和清潔的綠色智能懸架將是今后汽車后橋的發(fā)展趨勢(shì)。
汽車驅(qū)動(dòng)橋是汽車的重要總成，驅(qū)動(dòng)橋設(shè)計(jì)是汽車設(shè)計(jì)的重要組成部分之一。目前國(guó)內(nèi)外驅(qū)動(dòng)橋設(shè)計(jì)出現(xiàn)了一下一些變化：1、主要部件和功能向驅(qū)動(dòng)橋的中部集中。有些廠家開(kāi)始把主減速器,?制動(dòng)器和行星減速機(jī)構(gòu)等集合在橋的中部,?但其優(yōu)點(diǎn)尚待考證。2、橋殼采用球墨鑄鐵,?以提高整橋外觀質(zhì)量。橋殼采用球墨鑄鐵,?加工成本低,?其鑄造及加工后的外觀質(zhì)量均比現(xiàn)在大多采用的鑄鋼橋有了很大的提高。3、適應(yīng)特種要求的多功能驅(qū)動(dòng)橋。為適應(yīng)主機(jī)產(chǎn)品的特殊要求,?驅(qū)動(dòng)橋產(chǎn)品供應(yīng)廠家設(shè)法在橋上增加引進(jìn)了一些特殊功能:自動(dòng)充氣功能、超載報(bào)警功能、增添轉(zhuǎn)向油缸功能等,?增加了驅(qū)動(dòng)橋產(chǎn)品的適應(yīng)性。驅(qū)動(dòng)橋的結(jié)構(gòu)型式與驅(qū)動(dòng)車輪的懸掛型式密切相關(guān)。當(dāng)驅(qū)動(dòng)車輪采用非獨(dú)立懸掛時(shí)，都是采用非斷開(kāi)式驅(qū)動(dòng)橋；當(dāng)驅(qū)動(dòng)車輪采用獨(dú)立懸掛時(shí)，則配以斷開(kāi)式驅(qū)動(dòng)橋。與非斷開(kāi)式驅(qū)動(dòng)橋相比較，斷開(kāi)式驅(qū)動(dòng)橋能顯著減少汽車簧下質(zhì)量，從而改善汽車行駛平順性，提高了平均行駛速度；減少了其策劃行駛時(shí)作用于車輪和車橋上的動(dòng)載荷，提高了零部件的使用壽命；增加了汽車的離地間隙；由于驅(qū)動(dòng)車輪與路面的接觸情況及對(duì)各種地形的適應(yīng)性較好，增強(qiáng)了車輪的抗側(cè)滑能力；若與之配合的獨(dú)立懸架導(dǎo)向機(jī)構(gòu)設(shè)計(jì)合理，可增加汽車的不足轉(zhuǎn)向效應(yīng)，提高汽車的操縱穩(wěn)定性。但其結(jié)構(gòu)復(fù)雜，成本較高。斷開(kāi)式驅(qū)動(dòng)橋在乘用車和部分越野汽車上應(yīng)用廣泛。非斷開(kāi)式驅(qū)動(dòng)橋結(jié)構(gòu)簡(jiǎn)單，成本低，工作可靠，但由于其簧下質(zhì)量較大，對(duì)汽車的行駛平順性和降低動(dòng)載荷有不利的影響。
3. 課題設(shè)計(jì)（或研究）的內(nèi)容
主要研究：純電動(dòng)迷你巴士的驅(qū)動(dòng)橋設(shè)計(jì)。參照純電動(dòng)迷你客車的基本參數(shù)及相關(guān)汽車的參數(shù)，查閱有關(guān)資料，完成純電動(dòng)迷你巴士的驅(qū)動(dòng)橋的計(jì)算和結(jié)構(gòu)設(shè)計(jì)。
4. 設(shè)計(jì)（或研究）方法
通過(guò)查閱汽車構(gòu)造、汽車?yán)碚?、汽車設(shè)計(jì)、汽車車身結(jié)構(gòu)與設(shè)計(jì)、車身造型、汽車車型手冊(cè)、現(xiàn)代電動(dòng)汽車、混合動(dòng)力電動(dòng)汽車和燃料電池車基本原理、理論和設(shè)計(jì)及網(wǎng)上的有關(guān)汽車的資料來(lái)進(jìn)行設(shè)計(jì)。
5. 實(shí)施計(jì)劃
第6周 全組集體討論，確定總體方案
第7-10周 完成設(shè)計(jì)計(jì)算，開(kāi)始繪圖。
第10-12周 完成繪圖。
第13周 按要求整理、編寫設(shè)計(jì)說(shuō)明書、整理圖紙及全部設(shè)計(jì)文件，翻譯英文資料，將全部畢業(yè)設(shè)計(jì)資料交給指導(dǎo)教師。
第14周 老師審核、互審評(píng)閱設(shè)計(jì)，答辯，評(píng)定成績(jī)。
指導(dǎo)教師意見(jiàn)
指導(dǎo)教師簽字：年月日
教研室意見(jiàn)
教研室主任簽字：年月日
外文資料譯文
Driving Axle
l automobile driving axle
The driving axle is one of cross bars supporting a vehicle, on which the driving wheels turn .The driving axle includes a housing ,an axle drive ,a differential , tow axle shafts (half axles ),and final drives (if any ) .
The axle .or main, drive is a drive-line unit that increases the torque delivered by the transmission and transmits it to the driving wheels, via the differential. In automobiles, the axle drive shaft, usually called the propeller shaft.
The axle drive may be a Single or a double-stage type, the former comprising a pair of gears and the latter .tow pairs of gear. Drive pinion I may be made integral with its shaft, or it may be detachable from the shaft. Driving gears and are usually made in the form of detachable gear rings that are bolted or riveted to the differential case .Alex drive bevel pinions and gears are made with helical teeth in order to reduce noise in operation.
The tow-stage axle drive consists of a pair of bevel gears and a pair of spur gears. Drive bevel pinion drives bevel gear that is fixed to the flange of the intermediate shaft made integral with 2nd –stage driving spur gear .Gears meshes with driven spur gear which is fastened to the case rotates in taper roller bearings installed in the differential carrier that makes part of the driving axle housing.
The differential is a drive-line unit that divides the torque applied to it between the tow axle shafts and allows one driving wheel to turn at a different speed from the other.
The differential consists of case, cross or spider pinion .and side gears, also known as axle gears .the differential pinions are freely mounted on the cylindrical arms of the spider, which is held in the differential case, and remain in constant mesh with the differential side gears.
When the automobile is moving down a straight and even road, both driving wheels meet with one and the same rolling resistance. In this case, axle driven gear, or differential ring gear, causes the differential case to rotate .when the differential case rotates pinions and their spider arms move around in a circle with tow differential side gears are meshed with the pinions, the side gears must rotate, causing the axle shafts and their associated driving wheels to turn. With equal resistance applied to each wheel, the differential pinions do not rotate. They apply equal torque to the side gears and therefore both driving wheels rotate at one and the same speed is unequal ,the differential pinions rotate on their spider arms as well as drive round with the differential case .supposing that one of the axle shaft is prevented from rotating ,the differential pinions would have to walk around the stationary side gear ,causing the other side gear to rotate at twice its normal speed .You can now see how the differential can allow one driving wheel to turn faster than the other .
Whenever the automobile goes around a turn ,the outer driving wheel travels a greater distance than the inner drive wheel .the inner wheel speeds up proportionately ,thanks to the differential pinions that rotate on their spider arms and ,rolling around the slower side gear send more rotary motion to the outside wheel.
The differential side gears are splined on to the inner ends of the axle shafts .The other ends of the shafts are attached to the driving wheel hubs by means of flanges .Trucks use full floating axle shafts .Such axle shafts are acted upon by torque only .All the other loads acting on the driving wheels are taken by the driving axle housing, because the wheel hubs are supported by bearings mounted on the housing.
l Driving axle of general-purpose wheeled tractor
General-purpose wheeled tractors are a four-wheel drive type, they have tow driving axles-front and rear .Both axles are similar in construction, expect for the housing. Each driving axle consist if a housing, an axle drive ,a differential ,and final drives .The front and rear-axles drives are interchangeable and comprise a pair of spiral bevel gears . The axle drive pinion is made integral with a shaft that is supported by tow taper roller bearings installed in axle drive pinion carrier .The latter is accommodated in differential carrier and is fixed to it by bolts. The flange of the axle drive pinion carrier is provided with threaded holes to fit puller screws that are used to remove the axle drive pinion carrier from the differential carrier .The position of the drive pinion relative to the centerline of the axle is adjust by means of a pack of shims placed under the flange of the drive pinion carrier Shims palace under the cone of the front bearing are used to adjust the preload on the drive pinion bearings. Splined to adjust the preload on the drive pinion shaft is universal-joint flange .The axle drive gear is bolted to the differential case flange.
THE DIFFERENTIAL consists of case, four pinions, and tow side gears .The differential case comprise tow halves that are bolted together and supported by taper roller bearings installed in the differential carrier .Screwed in the bearings housing from the outside are nuts used to adjust the backlash between the ring gear and drive pinion teeth and the side bearing preload.
Welded to the top of the driving axle housing at both its ends are spring pads .The housing of both its ends are spring axels are provided with filler ,overflow ,and drain holes closed by plugs .Both housing also have vents ,The rotating components of the driving axles are lubricated with transmission oil .
As distinct from the automobiles considered in this text, all tractors include final drives in their power trains .The final drives of general-purpose wheel tractors are referred to as wheel-hub reduction gears.
While transmitting power to the driving wheels, wheel-hub reduction can increase their torque .These are planetary reduction gear sets consist of sun gear ,or wheel ,three planet ,or pinion ,gears ,planet or pinion ,carrier .stationary internal ,or ring ,gear ,and housing.
The sun gear is splined to the outer end of the axle shaft is splined to the differential side gear .The cylindrical planet gears are in constant mesh with both the sun gear and the ring gear and are free to rotate on roller bearings mounted on shafts that are attached to the planet carrier .The planet carrier is fasted to the reduction gear housing by means of studs and nuts .The flange of housing ,driving wheel brake drum 13,and wheel hub are clamped together by bolts .The planet carrier and reduction gear housing form the driven part of the planetary gear set and rotate with the driving wheel of the tractor .The driving gear hub is supported by taper roller bearings mounted on axle shaft housing ,or axle sleeve .The axle sleeve is connected to the stationary ring gear by means of adapter hub that has internal splines and external teeth . The splines are meshed with matching splines on the axle sleeve, and the teeth are meshed with internal teeth ring gear.
Wheels and its maintain
Modern wheeled tractors and automobiles use pneumatic-tired disc wheels. As a result of the driving wheel tires gripping the road, the rotary motion of the wheels is transformed into the translational motion of the tractor or automobile.
According to their purpose, wheels are classified as driving .driven steerable, and combination types.
Trucks and general-purpose wheeled tractors have all their wheels of one and the same size .Row-crop tractors have their rear wheels larger than the front wheels .The rear wheels carry the major proportion of the load due to the weight of the tractor .The front wheels are loaded lighter and this makes them easier to turn and provide good directional steering stability, which is essential for row-crop work.
A TRUCK WHEEL consists of disc and flat base rim that is made integral with it, while the other flange is formed by detachable side ring that is held to the rim by split lock ring on the rim .which doubles as a side ring and a lock ring.
The wheel disc is provided with holes for mounting the wheel on the wheel mounting bolts ,or wheel studs ,on the wheel hub ,where it is fixed by nuts .Both the holes and the nuts are tapered to ensure exact location of the wheel on its hub .The rear driving axles of trucks carry tow wheels at each end .The inner wheels are held to the hubs by cap nuts that are threaded both on the inside and on the outside .and the outer wheels are mounted on the cap nuts and fixed in place by taper nuts screwed on the nuts .
The wheel nuts on the right side of truck have right-hand threads, whereas the nuts on the left side of the truck are threaded left-hand .The reason is to tighten the nuts, not loosen them, and thus prevent them from working loose on acceleration and braking.
An automobile pneumatic tire consists of casing, inner tube, and flap .The tire casing comprises tread, side walls, and beads .Tires for good roads use small tread patterns, while those for bad roads or cross –country service large tread patterns.
The inner tube is made in the form of a hollow elastic rubber doughnut that is inflated with air after it is installed inside the tire and the tire is put on the wheel rim .The inner tube is inflated through tire valve that consists of housing 11,valve inside ,and cap .The valve housing is made of brass in the dorm of a flanged tube that is mounted in the inner tube by means of a washer and a nut and sticks out through a hole in the wheel .Some tire valve housing are of comprise construction :the upper part is made of brass and the lower part ,of rubber that is vulcanized on to the inner tube .The valve inside is a check valve that opens to let air in the inner tube when an air closed ,spring pressure and air pressure inside the tube hold the valve .When the valve is closed ,spring pressure and air pressure inside the tube hold the valve in its seat .It includes core with a rubber ring ,a plunger pin ,and a spring .The valve inside is Screwed in the tire valve housing and is closed by the cap Screwed on the housing.
To the construction of the driving and steerable wheels, each wheel comprises hub , disc with rim ,and tire with inner tube .The rim is welded to the disc and the disc is bolted to the hub .
The driving wheel tires are of low-pressure type and have heavy tread bars for better traction.
The driving wheel hub is keyed to axle shaft and is fixed in place by means of bolted-on insert with worm whose threads mesh with the rack teeth cut in the half axle .By turning the worm one can change the position of the wheel on the axle shaft to obtain the desired track width .Before doing this ,it is necessary to jack up the rear part of the tractor to clear the wheels of the ground and loosen the bolts that hold the inserts to the wheels hubs .Should this adjustment prove insufficient ,the track width can further be increased by placing the wheels with the concaves of their discs facing inwards.
On some row-crop tractors ,the rear wheel discs are bolts to lugs welded on the wheel rims .In this case ,the crack width can be changed by bolts the discs in alternative positions to the lugs .Also the concave wheel discs may be used either with the concave facing inwards or outwards.
Trouble-free operation of automobiles and wheeled tractors largely depends on the condition of the tires. Therefore, during operation, one should adhere to following rules.
Prevent fuel and, or oil from getting onto the tires. Cleans the tires regularly from dirt and remove all foreign articles, such as stones, form the treads. Do not apply brakes sharply, never start away form rest with a jerk, and avoid making sharp turns, for all this causes uneven wear of the tires. Do not allow excessive slipping of the driving wheels. When preparing your tractor or automobile for a long-term storage, jack up the wheels and put trestles under the axles or frame to relieve the tires.
The service life of tires is expressed in terms of their mileage. For most bias (ordinary) truck tires, the guaranteed mileage amounts to 50000 km. Observing the above rules will help prolong the useful service life of tires.
驅(qū)動(dòng)橋
汽車的驅(qū)動(dòng)橋
驅(qū)動(dòng)橋是一個(gè)支撐車輛的十字交叉的軸，它可以驅(qū)動(dòng)車輪運(yùn)動(dòng)。驅(qū)動(dòng)橋包括：驅(qū)動(dòng)橋殼、主減速器傳動(dòng)軸、差速器、兩個(gè)半軸和末端傳動(dòng)裝置。
主減速器在傳動(dòng)中的功用是增大變速器傳來(lái)的轉(zhuǎn)矩，憑借差速器把它傳遞給驅(qū)動(dòng)車輪。在汽車中主減速器傳動(dòng)軸把轉(zhuǎn)矩按正確的方向傳給驅(qū)動(dòng)輪，通常被叫做推進(jìn)器。
主減速器有單級(jí)和雙級(jí)兩種形式，前者包含一對(duì)齒輪，后者包含兩對(duì)齒輪。主動(dòng)小齒輪可以和軸做成一個(gè)整體，也可以做成分開(kāi)的。從動(dòng)齒輪常做成齒圈形式，差速器殼可以用螺栓或鉚釘連接在齒圈上，主減速器的小齒輪和大齒輪可以做成螺旋齒，這樣可以在嚙合時(shí)減少噪音。
雙級(jí)主減速器包含一對(duì)錐齒輪和一對(duì)圓柱齒輪，主動(dòng)齒輪帶動(dòng)從動(dòng)錐齒輪旋轉(zhuǎn)而從動(dòng)錐齒輪和小圓柱齒輪通過(guò)中間軸連在一起從而使小圓柱齒輪轉(zhuǎn)動(dòng)，它與差速器殼固定在一起的大圓柱齒輪嚙合，差速器殼的旋轉(zhuǎn)帶動(dòng)差速器運(yùn)動(dòng)并和軸承裝設(shè)構(gòu)成橋殼的一部分。
差速器在傳動(dòng)系中將轉(zhuǎn)矩分開(kāi)分別驅(qū)動(dòng)兩側(cè)半軸，并且允許一側(cè)驅(qū)動(dòng)輪和另一側(cè)驅(qū)動(dòng)輪以不同的角速度運(yùn)動(dòng)。
差速器包括差速器殼、行星齒輪軸（十字軸），行星齒輪，側(cè)面齒輪即半軸齒輪。行星齒輪可以安裝在卡在差速器殼上的圓柱形十字軸上，并且保持與半軸齒輪的不斷嚙合。
當(dāng)汽車直線行駛和在水平路面上運(yùn)動(dòng)時(shí)，兩側(cè)驅(qū)動(dòng)輪將會(huì)遇到相同的滾動(dòng)阻力。在這種情況下，主減速器從動(dòng)齒輪帶動(dòng)差速器殼旋轉(zhuǎn)。當(dāng)差速器殼旋轉(zhuǎn)時(shí)差速器行星齒輪和十字軸也旋轉(zhuǎn)運(yùn)動(dòng)，因?yàn)榘胼S齒輪差速器行星齒輪嚙合，半軸齒輪必須旋轉(zhuǎn)，導(dǎo)致半軸與兩側(cè)車輪也運(yùn)動(dòng)。當(dāng)每一個(gè)車輪承受的阻力相等時(shí)，差速器小齒輪不再旋轉(zhuǎn)，它們給半軸齒輪提供相等的轉(zhuǎn)矩且兩側(cè)車輪以一個(gè)相同的角速度旋轉(zhuǎn)。當(dāng)然，當(dāng)阻力不相等時(shí)，差速器行星齒輪既繞著差速器殼公轉(zhuǎn)又繞十字軸自轉(zhuǎn)，如果一側(cè)半軸不旋轉(zhuǎn)時(shí)，行星齒輪不會(huì)繞著固定不動(dòng)的半軸齒輪運(yùn)動(dòng)，使另一側(cè)半軸齒輪以平常兩倍的速度旋轉(zhuǎn)。這樣你就明白差速器是怎么使一側(cè)齒輪轉(zhuǎn)速大于另一側(cè)的。
無(wú)論什么時(shí)候汽車轉(zhuǎn)彎行駛時(shí)，外側(cè)車輪總比內(nèi)側(cè)的車輪移過(guò)的距離大。內(nèi)側(cè)車輪會(huì)慢下來(lái)，而外側(cè)車輪則成比例地加速，由于差速器在十字軸上自轉(zhuǎn)，且在速度慢的一側(cè)的半軸齒輪上滾動(dòng)，它將使外側(cè)車輪移動(dòng)的快一些。
半軸內(nèi)端用花鍵與差速器半軸齒輪連接，外端用凸緣與驅(qū)動(dòng)輪輪轂相連。載貨汽車采用全浮式半軸。這樣的半軸只承受轉(zhuǎn)矩作用。其余的負(fù)載由橋殼承擔(dān)，因?yàn)檩嗇炗砂惭b在橋殼上的軸支撐的。
輪式拖拉機(jī)的驅(qū)動(dòng)橋
一般的輪式拖拉機(jī)采用四輪驅(qū)動(dòng)的形式，它有兩個(gè)驅(qū)動(dòng)橋——前驅(qū)動(dòng)橋和后驅(qū)動(dòng)橋。除了橋殼之外，兩個(gè)橋的構(gòu)造很相似。每個(gè)驅(qū)動(dòng)橋都包括橋殼，主減速器，差速器和末端傳動(dòng)裝置。前后驅(qū)動(dòng)橋可以互換，且都包含一對(duì)螺旋錐齒輪。主減速器的主動(dòng)錐齒輪與軸做成一體，并由兩對(duì)圓錐滾子軸承支撐，并用螺栓與差速器殼聯(lián)接。主動(dòng)錐齒輪凸緣外有螺紋孔與配套的螺釘，用于防止主動(dòng)錐齒輪在差速器殼作用下運(yùn)動(dòng)。關(guān)系到車軸中心線的主動(dòng)錐齒輪的位置是由裝在主動(dòng)錐齒輪后的調(diào)整墊片來(lái)調(diào)整的，裝在圓錐滾子軸承內(nèi)座圈的調(diào)整墊片用來(lái)調(diào)試安裝在主動(dòng)錐齒輪上的軸承的預(yù)緊力。齒輪軸的軸徑末端的凸緣采用一般的花鍵聯(lián)接。從動(dòng)錐齒輪用螺栓與差速器殼凸緣固定在一起。
差速器包括差速器殼、四個(gè)小行星齒輪，兩側(cè)半軸齒輪。差速器殼由兩部分構(gòu)成，它們用螺栓連接在一起，并由圓錐滾子軸承裝置支撐。軸承套外面的螺母用來(lái)避免齒圈和主動(dòng)錐齒輪發(fā)生運(yùn)動(dòng)干涉，使它們正確嚙合，并調(diào)整軸承的預(yù)緊力。
焊在橋殼兩端頂部的是彈簧緩沖器，每個(gè)橋殼上都有注油孔，并用油塞塞住。每個(gè)橋殼都有一個(gè)通風(fēng)孔。橋殼內(nèi)的旋轉(zhuǎn)運(yùn)動(dòng)部件都涂有潤(rùn)滑劑。
在本書之中所有靠末端傳動(dòng)提供動(dòng)力的拖拉機(jī)與汽車考慮的地方有所不同?？磕┒藗鲃?dòng)的一般用途的輪式拖拉機(jī)有的裝有輪邊減速器。
當(dāng)傳來(lái)的轉(zhuǎn)矩驅(qū)動(dòng)車輪運(yùn)動(dòng)時(shí)，輪邊減速器也可以增大扭矩。這些像行星般運(yùn)動(dòng)的減速齒輪裝置包括太陽(yáng)輪、行星齒輪、行星架、齒圈和減速器殼。
太陽(yáng)輪用花鍵聯(lián)結(jié)在半軸外側(cè)的末端并且用鎖緊螺母擰緊固定。半軸的另一端則用花鍵聯(lián)結(jié)著半軸齒輪。圓柱行星齒輪分別與太陽(yáng)輪和齒圈嚙合，且繞裝在行星齒輪軸上的滾子軸承自轉(zhuǎn)，行星齒輪軸安裝在行星架上，行星架用螺栓和螺母固定在減速器殼上。減速器殼上的凸緣，制動(dòng)鼓，輪轂，用螺栓固定在一起，行星架，減速器殼上的行星裝置的運(yùn)動(dòng)部件與驅(qū)動(dòng)輪一起旋轉(zhuǎn)運(yùn)動(dòng)。齒輪座由半軸套管上的滾子軸承支撐。半軸套管與固定的齒圈用接合套連接起來(lái)，接合套有內(nèi)花鍵槽和外齒。內(nèi)花鍵槽與半軸套上的花鍵嚙合，外齒與齒圈的內(nèi)齒嚙合。
太陽(yáng)輪驅(qū)動(dòng)行星齒輪運(yùn)動(dòng)，并使固定的齒圈旋轉(zhuǎn)。因?yàn)樾行驱X輪軸與行星架固定在一起，所以行星齒輪可以帶動(dòng)行星架旋轉(zhuǎn)，并通過(guò)減速器殼驅(qū)動(dòng)驅(qū)動(dòng)輪運(yùn)動(dòng)。
輪邊減速器的部件都通過(guò)減速器殼中央的一個(gè)孔來(lái)注入潤(rùn)滑油。這個(gè)孔有量油尺并用油塞塞住。量油尺上刻有兩個(gè)痕跡，一個(gè)是減速器殼內(nèi)的最大油位，另一個(gè)是其最低油位。
車輪及其保養(yǎng)
現(xiàn)代的輪式拖拉機(jī)和汽車都采用充氣式輪胎，輪胎與路面接觸，汽車和拖拉機(jī)的車輪滾動(dòng)來(lái)驅(qū)動(dòng)汽車運(yùn)動(dòng)。
按它們的用途分，車輪可分為乘用車用輪胎和牽引車用輪胎以及兩者相結(jié)合的類型。
在貨車及一般的輪式拖拉機(jī)中，每輛車所用的輪胎型號(hào)是一樣的。農(nóng)用拖拉機(jī)后輪比前輪大，后輪承受拖拉機(jī)載重的70%，并且后輪能提供更好的牽引力。前輪承受的重量少，它比較容易轉(zhuǎn)向且提供良好的行駛方向，這是農(nóng)用車必不可少的。
貨車的車輪包括輻板, 輪輞，輪輞是焊在輻板上的。當(dāng)輪輞與一個(gè)凸緣做成整體時(shí)，與另一凸緣則做成可分的側(cè)擋圈，它是由分裂的擋圈支撐，一些貨車車輪只有擋圈，它包含側(cè)擋圈和鎖環(huán)。
輻板上裝有車輪框架的螺栓孔，在輪轂上有雙頭螺栓，它配有螺母。在輪轂上的孔及螺母安裝在精確的位置。貨車后車橋采用雙車輪，內(nèi)側(cè)車輪有輪轂支撐并由螺母固定，螺栓兩頭都有螺紋，且內(nèi)側(cè)車輪裝有螺母，螺母上的外螺紋用鎖緊螺母固定。
貨車右側(cè)車輪輻板固定螺栓用右旋螺紋，左側(cè)車輪輻板固定螺栓用左旋螺紋。這可以使汽車在行駛中螺母變緊不拖松，并且可以防止它在汽車加速或制動(dòng)時(shí)變松。
汽車可沖氣式輪胎包括外胎、內(nèi)胎和墊帶。外胎有胎冠、棉布層和束帶層。輪胎在良好路面上使用的花紋細(xì)而淺，在壞路面上花紋則深而寬。
橡膠輪胎內(nèi)部是中空的，它可以充氣，它裝在輪圈內(nèi)。輪胎充氣用氣門閥充氣的，它包括座筒、閥體和蓋。座筒是有黃銅做成的，它用螺栓和墊片擰緊裝在車輪輪輞上的孔內(nèi)。一些輪胎氣門閥的材料是合成的，上面用黃銅制成，下面用經(jīng)過(guò)硫化的橡膠制成的。氣門閥的內(nèi)部有一裂縫，是為了讓空氣能充入輪胎。當(dāng)氣門閥關(guān)閉時(shí)，彈簧壓力和輪胎內(nèi)的空氣壓力使管子恢復(fù)原位。它包括帶橡膠環(huán)的氣門芯、活塞和彈簧。
對(duì)于農(nóng)用拖拉機(jī)的驅(qū)動(dòng)和前進(jìn)輪來(lái)說(shuō)，每個(gè)輪子都由輪轂，帶輪圈的輪輞，帶內(nèi)胎的輪胎的構(gòu)成。輪圈焊接在輪輞上，輪輞與輪轂用螺栓固定在一起。
驅(qū)動(dòng)輪的輪胎是低壓的，胎面有深花紋，這可以獲得較好的牽引力。
驅(qū)動(dòng)輪的輪轂要于半軸相適應(yīng)，且能代替螺栓，使螺紋與半軸的鍵齒嚙合。轉(zhuǎn)動(dòng)螺紋可以改變輪子在半軸上的位置，獲得想得到的輪距。那樣做之前需要用千斤頂支起拖拉機(jī)的后部，并清潔與地面接觸的輪子，松開(kāi)螺栓，使其插入輪轂，如果這樣的調(diào)整還不適合，輪距可以通過(guò)使輪輞凹面向內(nèi)來(lái)進(jìn)一步加大。
在一些收割機(jī)上，后輪輞與焊接在輪圈上的把手用螺栓固定在一起。在這種情況下，輪距可以通過(guò)改變?cè)诎咽稚陷嗇y螺栓的位置來(lái)改變。同樣，輪輞凹面可以朝向內(nèi)也可以朝向外。
汽車和拖拉機(jī)在使用過(guò)程中遇到的問(wèn)題多數(shù)是由輪胎的狀況引起的。所以，在使用過(guò)程中，應(yīng)遵循以下規(guī)定。
避免燃料或油弄到輪胎上。經(jīng)常清洗污物和胎面上英文字母縫里的沙石。盡量不要緊急制動(dòng)、不要長(zhǎng)時(shí)間不清理和避免急轉(zhuǎn)彎。這些因素會(huì)使輪胎磨損不均勻。同時(shí)也不允許驅(qū)動(dòng)輪過(guò)度滑動(dòng)。當(dāng)準(zhǔn)備長(zhǎng)時(shí)間擱置汽車時(shí)，要用千斤頂頂起車輪，在車軸下放一個(gè)支架或者框架，使車輪受到的壓力得以緩解。
輪胎的使用壽命是用行駛里數(shù)來(lái)表示的。對(duì)于大多數(shù)普通貨車的輪胎，它的壽命是50000Km。但是如果注意以上的規(guī)定，則可以延長(zhǎng)輪胎的使用壽命。
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