驅(qū)動橋畢業(yè)論文外文翻譯1

DRIVE AXLE ASSEMBLIESAfter studying this chapter, you will be able to: Explain the construction of different types of drive axle assemblies.List the parts of various drive axles. Compare the differences between a rear wheel and front wheel drive axle assembly.Describe the operating principles of drive axle assemblies.Drive axle assemblies have several important functions. They must hold the wheels on, keep them upright, allow them to be turned (in front, on four-wheel drive and front-wheel drive vehicles) and propel the wheels forward or backward. They must drive the wheels in such a manner that one can turn faster than the other, yet both must receive torque. Drive axle assemblies must absorb the driving force of the wheels, and transmit it to the frame through springs, control rods, etc. The axle assembly provides an anchorage for springs, supports the weight of the vehicle and forms the foundation upon which the wheel brakes are mounted. Obviously, the axle assemblies must be well constructed, using quality materials.HOUSING The axle housing is usually made of stamped steel parts welded together. Or, the center section of the housing may be made of cast steel. Two basic types have been used: the BANJO type housing (in wide use) and the SPLIT housing (little used) consisting of two or more pieces. AXLES Two steel axles are placed inside the housing. Their inner ends almost touch; and, in some cases, they do touch. The outer ends protrude out of the housing and form a base upon which the wheels, hubs, etc. are attached. The inner ends are splined and are supported by the differential assembly. The outer ends are supported in roller or hall bearings. ATTACHING WHEEL HUBS Two methods are employed to securc the wheelhubs to the axle. One emthod employs a taper on the axle end; tile other forms the axle end into a flange upon which the wheel is bolted. TYPES OF AXLES Live axles (axles that turn with the wheels) are of three basic types: full-floating, three-quarter-floating and semifloating. Most cars utilize the semi floating axle. Most trucks have full-floating axles. If tile axle breaks, tile wheel will not come off. Tile three types .DRIVING THE AXLES The real wheels of a vehicle must turn at different speeds when rounding the slightest corner (outside wheel must roll farther). Therefore, it is necessary to employ a unit called a DIFFEREN FIAL to drive the axles so both axles receive power, yet they are free to turn at different speeds.THE DIFFERENTIAL A splined axle side gear is placed on tile innersplined end of each axle. 1he axle side gear is supported by the differential case. The side gear is free to turn ill the case. The differential case may be turned. It will revolve about the axle side gears. The differential pinion shaft will turn with the case, bur tile axle side gears will not be driven. By bolting a large ring gear to the differential case. and connecting it to a ring gear pinion gear and shaft, it will be possible to turn the case. The propeller shaft will be attached lo the ring gear pinion shaft. When the propeller shaft turns the ring gear pinion, the pinion will turn the ring gear. The ring gear, in turn will revolve the differential case and pinion shaft. Tile axle side gears will still NOT TURN. By adding two differential pinion gears (the differential pinion shaft will pass through these gears) that mesh with the side gears, the revolving case will turn the axle side gears with it. DIFFERENTIAL ACTION The propeller shaft turns tile ring gear pinion shaft. The ring gear pinion turns the ring gear which, in turn, revolves the differential case. When the case turns, the differential pinion shaft turns with it. As the differential pinions are mounted on this shaft, they are forced to move with the case. Being meshed with the axle side gears, the pinions will pull the axle side gears along with them. When the car is moving in a straight line, the ring gear is spinning the case. The differential pinions and axle side gears arc moving around with the case, with no movement between the teeth of the pinions and axle side gears. The entire movement is like a solid unit.When rounding a turn, the case continues whirlingand pulling the pinions around on the shaft. As the outer wheel must turn faster, the outer axle side gear is now moving faster than the inner axle side gear. The whirIing pinions not only pull on both axle sidegears, but now begin to rotate on their shaft.Auto Mechanics Fundamentalswhile walking in the axle side gears. This allows them to pull on both axle side gears, while at the same time, compensating for difference in speed by rotating around their shaft. You can see detail A, the car is moving in a straight line. The pinion is pulling both gears, but it is not turning. In B, the right side axle gear is moving faster than the left axle gear. The pinion gear is still moving at the same speed. It is still pulling on both gears, but has now started to turn on the pinion shaft. This turning action, added to the forward rotational speed of the shaft, has caused the right-hand side gear to speed up and actually begin to pass the pinion shaft. Study Figs. 16-9 and 16-10. The reversewalking effect on the left-hand side gear has caused it to slow down. The differential action adjusts itself to any axle speed variation. If one wheel begins to slip, the axle on firm ground will stand still. The case continues spinning the pinions, but they will merely walk around the stopped axle gear and impart the torque to the spinning axle. A special traction differential is often used to overcome this tendency. It will be covered later in this chapter.DIFFERENTIAL CARRIER AND BEARINGSA heavy and rigid section is bolted to the housing. It contains the pinion gear, shaft, and bearings. This is termed the DIFFERENTIAL CARRIER. Two large bearing holders are provided to support the spinning differential case. These are termed CARRIER BEARINGS. In some applications, the carrier is made as a solid part of the axle housing. All the component parts of the axle housing, axles and differentialSPECIAL TRACTION DIFFERENTIAL To avoid the loss of driving force that occurs when one wheel begins to slip, special differentials are designed to automatically transfer the torque to the wheel that is not slipping. This enables the car to continue its forward motion. Although there are several variations, all employ the principle of a friction device (clutch plates or a cone clutch) to provide some resistance to normal differential action.CHRYSLER SURE-GRIP The Chrysler Sure-Grip differential is basically a standard model, but with several important additions. The axle side gears are driven not by two differential pinions but by four. This requires two separate pinion shafts.The two shafts cross, but are free to move in-dependently of each other, The shaft outer ends are not round, but have two flat surfaces that form a shallow V. These ramp-like surfaces engage similar ramps cut in the differential case. A series of four clutch discs are used in back of each axle side gear thrust member. Two of these discs are splined to the differential case, and two are splined to the thrust member. The thrust member is splined to the axle. When the thrust members push outward, the clutch discs are forced together, locking the axle to the case. SURE-GRIP DIFFERENTIALOPERATION-BOTH AXLES TURNING AT THE SAME SPEEDWhen the propeller shaft drives the pinion gear, the torque thrust is transmitted to the ring gear. As the ring gear drives the differential case, the pinion shafts are forced to rotate with the case. The differential pinions encounter resistance when they attempt to turn the axle side gears. This resistance is transferred to the pinion shafts that aredriving the pinions. As both ends of each pinion shaft are seated in tapered ramps, and since they have some "play" at this point, this forces the shafts to slide up the ramp surfaces. This sliding movement moves bothshafts n an outward direction. As each shaft moves outward, it moves its pinions in the same direction. The pinions press against the pinion thrust members, forcing them to lock up the clutches. This is the action when the car is traveling in a straight line. AXLES TURNING AT DIFFERENT SPEEDSWhen the car turns a corner, the inner shaft slows down. When this happens, the pinion gears will start turning on their shafts. They will walk around the slower shaft and speed up the other shaft. This walking causes the outer shaft to rotate faster than the differenfial case, allowing the pinion shaft on the outerside to slide down its ramp. This releases the pressure on the outer clutches and lets the differential unit operate much like the standard model. It shows differential action when one axle is moving faster than the other. Note that the slower moving axle is receiving most of the torque since it remains clutched to the case. This type of differential will provide better traction than the standard differential. It is particularly useful when roads are slippery and is also valuable in producing fast acceleration. A high-powered engine will often cause one wheel to spin during acceleration when using a standard differential. A somewhat different traction differential, uses cone clutches under coil spring pressure. A cross-sectional view is pictured in Drive Axle AssembilesThe Oldsmobile Anti-Spin differential, uses the pressure of the coil springs to force the clutch cones into tight engagement with the case. This action tends to lock the axles to the case. In order for differential action to occur, the cones must be forced to slip. If one wheel slips, the other will still receive some driving force via the cone. The Positive-Traction differential in functions in a similar manner. Another positraction differential is illustrated i. Construction is similar to that in Figs16-19 and 16-20 except disc clutches are employed instead of cone clutch.HYPOID GEARING To facilitate lowering the propeller shaft tunnel in the floor of the car, and to allow lowering the body of the car, many ring gear pinion gears enter and drive the ring gear somewhat below the centerline of the axles.This gearing setup, using a modified spiral bevel gear, is referred to as HYPOID gearing. A special hypoid lubricant is necessary to prevent premature wear due to the sliding, wiping action that takes place between the ring and pinion gear teeth. Study the construction used in the pinion shaft assembly. Take note of the two tapered roller bearings used to support the shaft. This type of bearing withstands both radial (forces working at right angles to the shaft) and longitudinal (lengthwise) thrust.SPIRAL BEVEL GEARING Another type of ring and pinion gearing uses the spiral bevel gear. This type of pinion gear meshes with the ring gear at the axle centerline. The spiral tooth shape allows an overlapping tooth contact that makes for quiet operation, as well as added strength. Before one tooth rolls out of contact with another, a new tooth contact is made. This distributes the torque load over several teeth. The cross section, shows the path of the churning lubricant (see arrows). Notice how it is thrown up and forward where it drops down and flows back, lubricating the ring gear and pinion gear, pinion bearings, etc.SPUR BEVEL More antiquated, as far as differential gearing is concerned, is the spur bevel. Auto Mechanics FundamentalsRING AND PINION The tooth contact position, as well as clearance and back lash (distance one gear will move back and forth Without moving the other gear), is of critical importance. Ring and pinions are always matched, and must be installed as a pair. NEVER REPLACE ONE WITHOUT THE OTHER. illustrates tooth clearance, backlash, as well as other gear tooth nomenclature. Correct and incorrect ring and pinion tooth contact patterns are shown in Fig. 16-28. The correct contact pattern is very important for strength, wear, and quiet operation. These patterns are brought out by coating the teeth (after cleaning) with Prussian blue or white lead compound. The gears are revolved in both directions, and contact pattern becomes visible. The drive side is side that contacts when the pinion is driving the ring. The coast pattern is when the ring is driving the pinion.譯文 驅(qū)動橋在學(xué)習(xí)本章之后，你將了解不同類型驅(qū)動橋的組成，并能列舉不同種類的驅(qū)動橋；比較后橋與前橋的不同之處；描述驅(qū)動橋的工作原理。驅(qū)動橋有很多重要作用。它可以使車輪回正，控制車輪滾動，可以使其中一個車輪的轉(zhuǎn)速比另外一個車輪快，兩個車輪均可獲得轉(zhuǎn)矩。驅(qū)動橋可以獲得來自于車輪的反作用力，通過彈簧，操縱桿等將作用力傳到車架上。驅(qū)動橋在車輪制動器被安裝的基礎(chǔ)上通過彈簧來固定，并獲得簧上質(zhì)量。很顯然，驅(qū)動橋需要使用高質(zhì)量的材料來制作。結(jié)構(gòu)后橋的幾個基本組成部分：橋殼，半軸，差速器。橋殼橋殼通常是由鋼板模壓件焊接在一起而制成的。橋殼的中心部分是由鑄鋼制成的。有兩種類型的橋殼常被使用：整體式橋殼（應(yīng)用廣泛）和分段式橋殼（應(yīng)用較少）是由兩個或者更多的部分組成。車橋兩個車橋在橋殼的內(nèi)部，它們在內(nèi)部相接觸，在某些位置它們是不接觸的。外部的凸出端附在車輪和輪轂上。內(nèi)部端被花鍵固定在差速器上，外端被滾子軸承所固定。連接輪兩種方法被應(yīng)用于驅(qū)動橋的輪轂上。一種方法是在驅(qū)動橋一端用拔銷來固定，另一端通過凸緣固定。半軸的類型半軸有三種基本的類型，全浮式， 3/4浮式和半浮式。大多是汽車采用半浮式，大部分貨車采用全浮式半軸支承。如果半軸折斷，車輪將停止轉(zhuǎn)動。驅(qū)動橋汽車轉(zhuǎn)彎時的工況與普通行駛時的不同，必須使用一個叫做差速器的單元使兩個半軸都獲得動力，讓左右驅(qū)動車輪的行駛速度不同。差速器每個半軸的一側(cè)都有齒輪，兩半軸齒輪可以自由運動?？梢钥吹讲钏倨鳉?，它會繞著半軸上的齒輪轉(zhuǎn)動。差速器殼上通過銷連接齒圈和軸。差速器殼體會隨著差速器轉(zhuǎn)動，傳動軸與主動齒輪軸相連接。當(dāng)傳動軸使主動齒輪軸轉(zhuǎn)動時，齒圈也會隨之轉(zhuǎn)動。齒圈會繞著差速器殼體和十字軸轉(zhuǎn)動。差速器的運動傳動軸使主動齒輪軸轉(zhuǎn)動，齒圈也會隨之轉(zhuǎn)動。當(dāng)差速器殼體轉(zhuǎn)動，十字軸隨之轉(zhuǎn)動。當(dāng)差速器上的行星齒輪被安裝在這個軸上時，它們會隨著差速器殼體運動。 當(dāng)汽車沿著直線方向行駛時，齒圈會繞著差速器殼體旋轉(zhuǎn)。差速器行星齒輪和半軸齒輪繞著差速器殼體轉(zhuǎn)動，輪齒之間無干涉。整個運動過程象一個固體單元。當(dāng)汽車轉(zhuǎn)彎時，差速器殼體繼續(xù)旋轉(zhuǎn)，推動行星齒輪繞著軸轉(zhuǎn)動。當(dāng)要求車輪快速轉(zhuǎn)動時，外部半軸齒輪的轉(zhuǎn)速高于內(nèi)部半軸齒輪。行星齒輪不僅僅是推動半軸齒輪轉(zhuǎn)動，也使它們的軸轉(zhuǎn)動。這可以使兩個半軸齒輪同時繞著其各自的軸轉(zhuǎn)動/圖A中，汽車沿直線行駛，行星齒輪推動兩個半軸齒輪轉(zhuǎn)動。在圖B中，右側(cè)半軸齒輪的轉(zhuǎn)速大于左側(cè)半軸齒輪的轉(zhuǎn)速。行星齒輪仍以相同的速度轉(zhuǎn)動，仍然推動兩個半軸齒輪轉(zhuǎn)動，也推動軸的轉(zhuǎn)動。這種運動會使右側(cè)半軸齒輪的轉(zhuǎn)速提高，從而超過十字軸的轉(zhuǎn)速。相反的運動形式會使左側(cè)半軸齒輪的轉(zhuǎn)速降低。差速器的這種運動形式可以調(diào)節(jié)其自身以及驅(qū)動橋的轉(zhuǎn)速變化。如果一個車輪開始打滑，驅(qū)動橋靜止不動。差速器殼體繼續(xù)旋轉(zhuǎn)，驅(qū)動橋齒輪靜止不動， 可以增加驅(qū)動橋的轉(zhuǎn)矩。一種有特殊結(jié)構(gòu)的差速器將在后面的章節(jié)做介紹。差速器殼和差速器殼軸承一個質(zhì)量大而且堅固的部分被安裝在橋殼內(nèi)，它包括行星齒輪，十字軸和軸承，稱之為差速器殼。其內(nèi)部裝有兩個大的軸承，稱之為差速器殼軸承。差速器殼是橋殼的一部分。橋殼的組成部分包括半軸和差速器特殊結(jié)構(gòu)的差速器為了避免動力的流失，車輪開始打滑時，特殊的差速器可以改變車輪的轉(zhuǎn)矩而避免車輪打滑。這樣可以使汽車原有的運動狀態(tài)保持不變。盡管存在著很多的變化，但可采用摩擦裝置來實現(xiàn)正常運動?？巳R斯勒高牽引力差速器克萊斯勒高牽引力差速器是一個標(biāo)準(zhǔn)模型，有很多重要的附加條件半軸齒輪不是由兩個差速器行星齒輪驅(qū)動的，而是由四個差速器行星齒輪驅(qū)動的。這就需要兩個分離的十字軸，兩個軸之間的運動是相互獨立的。軸的外端不是圓的而是平的，象V型。差速器殼體呈斜坡狀。半軸齒輪上裝有四個離合器盤，其中的兩個離合器盤繞著差速器殼體轉(zhuǎn)動，另外兩個繞著止推部分轉(zhuǎn)動。止推部分繞著半軸旋轉(zhuǎn)，離合器盤運動到一起。高牽引力差速器的運動兩個半軸的轉(zhuǎn)速相同。當(dāng)傳動軸驅(qū)動行星齒輪轉(zhuǎn)動時，轉(zhuǎn)矩被傳遞到齒圈上。正如齒圈可以驅(qū)動差速器殼體一樣，十字軸繞著差速器殼體轉(zhuǎn)動。半軸齒輪隨著差速器小齒輪轉(zhuǎn)動。十字軸驅(qū)動小齒輪轉(zhuǎn)動。兩個十字輪軸被置于不同的位置上。這種滑動使軸向外邊的方向運動。每個軸都向外運動，從而使軸上的行星齒輪向相同的方向運動，使離合器被鎖住。這是汽車沿直線行駛的運動規(guī)律。半軸轉(zhuǎn)速不同當(dāng)汽車轉(zhuǎn)彎時，其內(nèi)部軸的轉(zhuǎn)速降低。當(dāng)發(fā)生這種情況時，行星齒輪會使它的軸開始轉(zhuǎn)動。一個軸的轉(zhuǎn)速比較慢，另外一個軸的轉(zhuǎn)速加快。這樣會使外部軸的轉(zhuǎn)速高于差速器殼體的轉(zhuǎn)速，使外部齒輪軸產(chǎn)生滑動。所釋放的壓力使差速器的運動同標(biāo)準(zhǔn)模型一致。如所示差速器的一個半軸的轉(zhuǎn)速高于另外一個半軸的轉(zhuǎn)速。轉(zhuǎn)速較慢的半軸可以獲得大部分的轉(zhuǎn)矩。這種差速器優(yōu)于普通的差速器。當(dāng)?shù)缆饭饣臈l件下，可以提高速度。功率較高的發(fā)動機通常選用標(biāo)準(zhǔn)型差速器。不同類型的差速器。在彈簧線圈壓力下的錐形離合器。通過彈簧線圈而使錐形離合器安裝在差速器殼體內(nèi)。為了實現(xiàn)差速器的運動，需要使錐形離合器產(chǎn)生滑動。如果一個車輪產(chǎn)生滑動，另外一個車輪仍然可以通過彈簧線圈獲得動力。準(zhǔn)雙曲面齒輪式差速器為了使汽車地板下傳動軸的高度降低，車身高度降低，半軸上裝有很多小齒輪。這種差速器的建立，通過螺旋錐齒輪傳動，運動形式同準(zhǔn)雙曲面齒輪相同。使用準(zhǔn)雙曲面錐齒輪用極壓潤滑劑防止滑動是必要的。運動發(fā)生在齒圈和輪齒上。學(xué)習(xí)小齒輪軸結(jié)構(gòu)的應(yīng)用。注意觀察兩個滾子軸承對軸的支承作用。這種軸承起著止推作用。螺旋錐齒輪傳動另外一種類型的小齒輪傳動裝置采用螺旋錐齒輪傳動。這種類型的小齒輪與半軸中心的齒圈相配合。螺旋齒可以增強受力。很多輪齒會承受轉(zhuǎn)矩。直齒錐齒輪差速器的齒輪也有是直齒錐齒輪式的。你會發(fā)現(xiàn)輪齒是直齒形，這種齒輪會產(chǎn)生噪音，不能給直齒錐齒輪提供足夠的動力?？ōh(huán)和小齒輪輪齒接觸位置以及它們之間的間隙具有重要作用?？ōh(huán)和小齒輪相配合，總是成對出現(xiàn)的。不能用其他的組件來替代。正確的配合很重要，可以提供足夠的動力。