汽車(chē)驅(qū)動(dòng)橋課程畢業(yè)設(shè)計(jì)外文文獻(xiàn)翻譯、中英文翻譯、外文翻譯

附 錄 A 一、英文原材料 Drive Axle All vehicles have some type of drive axle/differential assembly incorporated into the driveline. Whether it is front, rear or four wheel drive, differentials are necessary for the smooth application of engine power to the road. The drive axle must transmit power through a 90 angle. The flow of power in conventional front engine/rear wheel drive vehicles moves from the engine to the drive axle in approximately a straight line. However, at the drive axle, the power must be turned at right angles (from the line of the driveshaft) and directed to the drive wheels. This is accomplished by a pinion drive gear, which turns a circular ring gear. The ring gear is attached to a differential housing, containing a set of smaller gears that are splined to the inner end of each axle shaft. As the housing is rotated, the internal differential gears turn the axle shafts, which are also attached to the drive wheels. The differential is an arrangement of gears with two functions: to permit the rear wheels to turn at different speeds when cornering and to divide the power flow between both rear wheels. (1)The accompanying illustration has been provided to help understand how this occurs. The drive pinion, which is turned by the driveshaft, turns the ring gear. (2)The ring gear, which is attached to the differential case, turns the case. (3)The pinion shaft, located in a bore in the differential case, is at right angles to the axle shafts and turns with the case. (4)The differential pinion (drive) gears are mounted on the pinion shaft and rotate with the shaft. (5)Differential side gears (driven gears) are meshed with the pinion gears and turn with the differential housing and ring gear as a unit. (6)The side gears are splined to the inner ends of the axle shafts and rotate the shafts as the housing turns. (7)When both wheels have equal traction, the pinion gears do not rotate on the pinion shaft, since the input force of the pinion gears is divided equally between the two side gears. (8)When it is necessary to turn a corner, the differential gearing becomes effective and allows the axle shafts to rotate at different speeds. As the inner wheel slows down, the side gear splined to the inner wheel axle shaft also slows. The pinion gears act as balancing levers by maintaining equal tooth loads to both gears, while allowing unequal speeds of rotation at the axle shafts. If the vehicle speed remains constant, and the inner wheel slows down to 90 percent of vehicle speed, the outer wheel will speed up to 110 percent. However, because this system is known as an open differential, if one wheel should become stuck (as in mud or snow), all of the engine power can be transferred to only one wheel. Engineers searched diligently for ways to allow each driving wheel to operate at its own speed. Many ideas were tried with mixed results before the basic design for the present-day, standard differential was finally developed. The successful idea that is still used in principle today was to divide the engine power by dividing the axle in two-attaching each driving wheel separately to its own half-axle and placing in between, an ingenious, free-rotating pinion and gear arrangement. The arrangement was called the differential because it differentiates between the actual speed needs of each wheel and splits the power from the engine into equal driving force to each wheel. On/off road vehicles and other trucks required to haul heavy loads are sometimes equipped with double reduction axles. A double reduction axle uses two gear sets for greater overall gear reduction and peak torque development. This design is favored for severe-ser-vice applications, such as dump trucks, cement mixers, and other heavy haulers. The double reduction axle uses a heavy-duty spiral bevel or hypoid pinion and ring gear combination for the first reduction. The second reduction is accomplished with a wide-faced helical spur pin-ion and gear set. The drive pinion and ring gear function just as in a single reduction axle. However, the differential case is not bolted to the ring gear. Instead, the spur pinion is keyed to and driven by the ring gear. The spur pinion is in turn constantly meshed with the helical spur gear to which the differential case is bolted. Many heavy duty trucks are equipped with two rear drive axles. These tandem axle trucks require a special gear arrangement to deliver power to both the forward and rearward rear driving axles. This gearing must also be capable of allowing for speed differences between the axles. Two axle hub arrangements are available to provide support between the axle hub and the trucks wheels: the semi-floating type axle and the fully floating type axle. Of the two ,the semi-floating is the simplest, cheapest design to incorporate ,but the fully floating axle is more popular in heavy-duty trucks. In the semi-floating type axle, drive power from the differential is taken by each axle half-shaft and transferred directly to the wheels. A single bearing assembly, located at the outer end of the axle, is used to support the axle half-shaft. The part of the axle ex-tending beyond the bearing assembly is either splined or tapered to a wheel hub and brake drum assembly. The main disadvantage of this type of axle is that the outer end of each axle shaft must carry and support the weight of the truck that is placed on the wheels. If an axle half-shaft should break ,the trucks wheel will fall off. Drive axle operation is controlled by the differential carrier assembly. A differential carrier assembly consists of a number of major components. These include: 1. Input shaft and pinion gear 2. Ring gear 3. Differential with two differential case halves, a differential spider ,four pinion gears ,and two side gears with washers. This differential assembly fits between the axle shafts, with the shafts being splined to the differential side gears. The parts of the differential carrier are held in position by a number of bearings and thrust washers. The leading end of the input shaft is connected to the drive shaft by a yoke and universal joint. The pinion gear on the other end of the input shaft is in constant mesh with the ring gear. The ring gear is bolted to a flange on the differential case. Insied the case, the legs of the spider are held in matching grooves in the case halves. The legs of the spider also support the four pinion gears. In addition ,the case houses the side gears ,which are in mesh with the pinions and are splined to the axle shafts. When the drive shaft torque is applied to the input shaft and drive pinion, the input shaft and pinion rotate in a direction that is perpendicular to the trucks drive axles. The drive pinion is beveled at 45 degrees and engages the ring gear, which is also beveled at 45 degrees, causing the ring gear to revolve at 90 degrees to the drive shaft. This means the torque flow changes direction and becomes parallel to the axles and wheels. The drive shaft must also be able to change in length while transmitting torque. As the rear axle reacts to road surface changes, torque reactions and braking forces, it tends to rotate for-ward or backward, requiring a corresponding change in the length of the drive shaft. In order to transmit engine torque to the rear axles, the drive shaft must be durable and strong. An engine producing 1 000 pound-feet of torque, when multiplied by a 12 to t gear ration in the transmission, will deliver 12 000 pound-feet breakaway torque to the drive shaft. The shaft must be strong enough to deliver this twisting force to a loaded axle without deforming or cracking under the strain. Drive shafts are constructed of high-strength steel tubing to provide maximum strength with minimum weight. The diameter of the shaft and wall thickness of the tubing is determined by several factors maximum torque and vehicle payload, type of operation, road conditions, and the brake torque that might be encountered. One-piece ,two-piece ,and three-piece drive shafts are used, depending on the length of the drive line. Each end of the drive shaft has a yoke used to connect the shaft to other drive line components. The yoke might be rigidly welded to the shaft tube or it might be a spline, or slip yoke. The tube yokes are connected through universal joints to end yokes on the output and input shafts of the transmission and axle. A typical slip joint consists of a hardened, ground splined shaft welded to the drive shaft tube that is inserted into a slip yoke that has matching internal splines. The sliding splines between a slib joint and a permanent joint must support the drive shaft and be capable of sliding under full torque loads. The propeller shaft is generally hollow to promote light weight and of a diameter sufficient to impart great strength. Quality steel, aluminum, and graphite are used in its construction. Some have a rubber mounted torsional damper. The universal yoke and splined stub (where used) are welded to the ends of a hollow shaft. The shaft must run true, and it must be carefully balanced to avoid vibrations. The propeller shaft is often turning at engine speeds. It can cause great damage if bent, unbalanced or if there is wear in the universal joints. As the rear axle moves up and down, it swings on an arc that is different from that of the drive line. As a result, the distance between transmission and rear axle will change to some extent. When the propeller shaft turns the differential, the axles and wheels are driven forward. The driving force developed between the tires and the road is first transferred to the rear axle housing. From the axle housing, it is transmitted to the frame or body in one of three ways: 1. Through leaf springs that are bolted to the housing and shackled to the frame. 2. Through control or torque arms shackled to both frame and axle housing. 3. Through a torque tube that surrounds the propeller shaft which is bolted to the axle housing and pivoted to the transmission, by means of a large ball socket. 二、中文翻譯 驅(qū)動(dòng)橋 汽車(chē)傳動(dòng)系統(tǒng)中驅(qū)動(dòng)橋和差速器有許多形式。無(wú)論是前輪、后輪還是四輪驅(qū)動(dòng)，差速器都是必要的，以便使發(fā)動(dòng)機(jī)的功率充分的發(fā)揮到路面上。 驅(qū)動(dòng)橋必須通過(guò)一個(gè) 90角傳遞動(dòng)力。以傳統(tǒng)的后輪驅(qū)動(dòng)汽車(chē)為例， 動(dòng)力由前置引擎?zhèn)鞯酱笾略谝粭l直線上的驅(qū)動(dòng)橋，然后動(dòng)力必須經(jīng)過(guò)一個(gè)直角傳遞給驅(qū)動(dòng)車(chē)輪。 這一過(guò)程是通過(guò)一個(gè)小齒輪傳遞到一個(gè)齒圈上而完成的。該齒圈連接到差速器殼，殼里面裝有一組小齒輪，小齒輪與帶有花鍵的每個(gè)軸的軸端相聯(lián)接，由橋殼的旋轉(zhuǎn)，從而差速齒輪帶動(dòng)軸轉(zhuǎn)動(dòng)，這個(gè)軸同時(shí)連接的就是驅(qū)動(dòng)車(chē)輪。 圖示為一個(gè)典型驅(qū)動(dòng)橋的組成 差速器齒輪具有兩個(gè)基本的功能：在轉(zhuǎn)彎時(shí)允許后輪以不同的速度轉(zhuǎn)動(dòng)并將動(dòng)力分配到兩后輪。 （ 1）提供的說(shuō)明是為了幫助理解這一過(guò)程是如何實(shí)現(xiàn)的。軸帶動(dòng)小驅(qū)動(dòng)齒輪在齒圈上旋轉(zhuǎn)。 （ 2）該齒圈與差速器殼相連 ，并帶動(dòng)殼旋轉(zhuǎn)。 （ 3）差速器殼內(nèi)設(shè)有一小孔，放置一個(gè)小齒輪軸，該小軸與差速器成直角，并隨殼體轉(zhuǎn)動(dòng)。 （ 4）差速行星齒輪驅(qū)動(dòng)裝在小軸上的齒輪，使軸轉(zhuǎn)動(dòng)。 （ 5）差速器邊上的齒輪（驅(qū)動(dòng)齒輪）與小齒輪嚙合，并與做在一體的差速器殼和齒圈一起轉(zhuǎn)動(dòng)。 （ 6）一側(cè)帶花鍵的齒輪與兩軸端配合，隨橋殼旋轉(zhuǎn)。 （ 7）當(dāng)兩車(chē)輪具有相同的驅(qū)動(dòng)力的時(shí)候，小齒輪（行星齒輪）在其軸架（行星架）上不旋轉(zhuǎn)，輸入到小齒輪上的力平均分配給兩端的齒輪。 （ 8）當(dāng)需要轉(zhuǎn)彎時(shí)，差動(dòng)齒輪開(kāi)始起作用，能夠?qū)崿F(xiàn)兩端的半軸以不同的速度旋轉(zhuǎn)。 由于內(nèi)側(cè)車(chē)輪速度 減慢，同側(cè)的花鍵軸齒輪也變慢，行星齒輪作為平衡杠桿，保持兩邊的輪齒負(fù)荷相等，同時(shí)允許兩邊的半軸以不同的的速度旋轉(zhuǎn)。如果汽車(chē)的行進(jìn)速度保持不變，內(nèi)側(cè)車(chē)輪的速度將減低 90%。外側(cè)車(chē)輪的速度將增加到 110%。但是，因?yàn)橄到y(tǒng)有差速器，所以一旦有一個(gè)車(chē)輪轉(zhuǎn)速保持不變（如在泥或雪地），那么 所有的發(fā)動(dòng)機(jī)功率 將全部 轉(zhuǎn)移到 另外的 一個(gè)車(chē)輪。 工程師們努力地尋找方法使每個(gè)驅(qū)動(dòng)輪都按照自己的速度運(yùn)行。在如今標(biāo)準(zhǔn)的差速器被最終發(fā)明出來(lái)之前，許多想法被交叉嘗試。目前在理論上非常成功的、一直沿用到今天的想法是通過(guò)把車(chē)軸分離成對(duì)稱的兩部分 。每一個(gè)半軸都連接到分離的驅(qū)動(dòng)輪上，然后中間安放一個(gè)獨(dú)立的自由旋轉(zhuǎn)的小齒輪和其它兩個(gè)齒輪來(lái)分離來(lái)自發(fā)動(dòng)機(jī)的動(dòng)力。這個(gè)結(jié)構(gòu)被稱為差速裝置。因?yàn)檫@種裝置能提供給每個(gè)車(chē)輪實(shí)際所需要的速度并且把來(lái)自發(fā)動(dòng)機(jī)的動(dòng)力分成相同的驅(qū)動(dòng)力作用給每個(gè)車(chē)輪。許多卡車(chē)有時(shí)需要裝備雙級(jí)減速驅(qū)動(dòng)橋來(lái)拖拽重物。雙級(jí)減速驅(qū)動(dòng)橋使用兩套減速齒輪來(lái)降低速度使轉(zhuǎn)矩達(dá)到峰值。這種設(shè)計(jì)是非常受優(yōu)待的例如自卸式卡車(chē)、混凝土攪拌車(chē)和其它重型貨車(chē)。 雙減速車(chē)橋采用了重型的螺旋錐齒輪或準(zhǔn)雙曲面齒輪和環(huán)行齒輪配合從而進(jìn)行第一級(jí)減速。第二級(jí)減速是通過(guò)寬面的螺旋柱 形直齒輪及其它齒輪組的配合完成的。主動(dòng)小齒輪和環(huán)行齒輪在 單級(jí)減速橋 上運(yùn)行，而差速器箱沒(méi)有被環(huán)形齒輪鎖死，相反，環(huán)形齒輪能將柱形直齒輪鍵入并驅(qū)動(dòng)，柱形直齒輪就可以依次不斷地與差速器箱中的螺旋正齒輪相嚙合。 許多重型載貨汽車(chē)都配備了兩個(gè)后驅(qū)動(dòng)橋，這種平衡懸架軸的卡車(chē)需要一種特殊的齒輪配置方法來(lái)解決后驅(qū)動(dòng)橋上的向前與向后的傳動(dòng)。這些齒輪必須要考慮到車(chē)軸間的轉(zhuǎn)速差。兩個(gè)車(chē)軸軸轂的排列為軸轂和車(chē)輪間提供了有力的支持。在 半浮動(dòng)式軸 與 全 浮動(dòng)式軸 中， 半浮動(dòng)式軸 的設(shè)計(jì)較簡(jiǎn)單、價(jià)格便宜的，而全 浮動(dòng)式軸 多受歡迎于重型卡車(chē)中。 對(duì) 于半浮動(dòng)式軸，來(lái)自差速器的動(dòng)力施加與兩個(gè)半軸，并直接傳遞到輪子上。一個(gè)單軸承組（位于軸承外端）被用于支撐半軸。軸端外延到軸承組上