ESP汽车英语中英对照Unit4passageA高等教育出版社.ppt

Automobile Drive Line,An automobile drive line is designed to transfer torque from an engine to an set of drive wheels. The usual system includes a coupling that joins the engine to the drive system, a transmission, a driveshaft, a geared differential, universal joints that connect the driveshaft to the transmission and differential, and two axles that drive the rear wheels. rear 后面的，后方的 汽车传动系的设计是用来把发动机产生的转矩传送到驱动车轮。通常这套系统包括一个用来连接发动机和驱动系统的装置，变述箱，传动轴，齿轮差速器把传动轴连接到变速箱和差速器的万向节和两根用来驱动后轮的半轴。,The Drive Line,The transmission is used to vary the ratio of crankshaft turns to driveshaft turns in order to obtain satisfactory power, acceleration, and fuel economy under alf conditions of load. It also makes it possible to reverse the direction of rotation of the driveshaft so that the vehicle can be driven in reverse. vary 改变；变化 ratio 比率 变速器是用来改变曲轴与传动轴之间的传动比以便在任何载荷的情况下都能获得令人满意的功率，加速度及燃油经济性。它同样也使政变传动轴的转向成为可能，从而使汽车可以实现倒行。,Both manually operated (standard) transmissions and automatic transmissions are currently in use. Three-speed and four-speed standard transmissions are available, as are two-speed and three-speed automatic transmtssions. manually 手动的 手动（标准配置）变速器和自动变速器当前都有使用。不仅可选用3速和4速标准手动变速器，而且也可选用2速和3速自动变速器。 Friction clutches couple engines to standard transmissions, and fluid couplings - nearfy always the torque converter type - are used with automatic units. 摩擦式离合器联结发动机与手（标准配置）变速器，液力耦台器（但多数是液力变矩器）则用于自动变速器。,The driveshaft connects the transmission to the differential, and the differential drives the rear axles. The differential provides a fixed ratio of driveshaft turns to rear axfe turns. Thus, it has much to do with the performance, and operating economy of a vehicle. Fixed 固定的 传动轴连接变速器与差速器，差速器驱动后轴转动。差速器提供一个固定的传动轴与驱动轴之间的传动比。因此，它与车辆的性能和操作经济性大有关系。 A few automobiles - both American and foreign are equipped with front wheel drive systems. 一些汽车（美国及美国以外的）装备前轮驱动系统。,Gears,Spur, helical, and hypoid gears and planetary gear sets are useed in automobile drive lines. Each type of gear has advantages and limitations. As a rule, hypoid gears are used in differentials, and the other types are used in transmissions. Helical 螺旋状的；hypoid 准双曲面齿轮的； planetary 行星的 正齿轮，螺线齿轮，准双曲面齿轮和行星齿轮组被用于汽车传动系。每种类型的齿轮各有其优越性和局限性。一般来说，螺线齿轮用于差速器，而其他类型的齿轮用于变速筘。,Gear ratio. In a specific transmission gear range, the torque of an automobile driveshaft and speed of the automobile depend on the torque and speed of the engine and on the gear ratios of the transmission and differential. The principles of speed and torque are well illustrated by the design of a gearset. For example, if a larger gear having a radius of 6 inches is meshed with a smaller gear of a 3-inch radius, the gear ratio is two to one (2:1). Since the larger gear has the same number of teeth per inch of gear circumference, it has twice as many teeth as the smaller gear. Therefore, the gear ratio of a pair of gears can be found by measuring the radius of each gear or by counting the number of teeth on each gear. gearset 齿轮组；radius 半径；meshed 啮和； circumference 圆周，周围 齿轮传动比，在限定的变速箱齿轮范围，汽车传动轴的扭矩和汽车的速度依赖于发动机的扭矩和转速以及变速籀和差速器的齿轮传动比。速度和扭矩原理可以很好地以齿轮组的设计说明。举例来说如果一个较大的6英寸半径的齿轮与一个较小的3英寸半径的齿轮一起啮合，那么齿轮传动比是二比一（2:1）。较大的齿轮在圆周上每一寸都具有相同齿数，但两倍于较小齿轮的齿数。因此，一对齿轮的传动比可以由测量每个齿轮的半径或计算每个齿轮上的齿数来确定。,Whenever the power output of a gear train is increased, the top speed is decreased. The reverse is also true. For example, the increased power output in the first gear range of a standard transmission results in a much lower top output shaft speed than is the case in the third gear range. 当变速器的输出转矩增加，最高速度就会下降。倒档也是同样。举例来说，在标准变速箱的一档转矩输出的增加造成它的最高转速要比三档低,The Clutch,A friction clutch is used to connect an engine to, and disconnect it from, a standard transmission so that the gears in the transmission can be shifted easily without clashing. Slippage in the clutch permits smooth operation when it is engaged or disengaged. disconnect 拆开，分离；clashing 猛撞，冲突；Slippage 滑动 摩擦离合器被用来将发动机连到（或断开）标准变速箱从而往变速箱可以不发生换档冲击的情况下很容易地实现变档。离合器的滑移允许在接合于断开时实现平滑的操作。,When a clutch is engaged, the driven plate is squeezed between the flywheel and a pressure plate assembly that is bolted to the flywheel. Since the input shaft of the transmission is splined to the hub of the driven plate, the engaging of the clutch provides a direct mechanical connection between the engine and the transmission. squeezed 压榨，挤； splined 花键，用花键联接 当离合器处于接合状态，从动片被飞轮和一个被装配到飞轮上的压板总成压挤。因为变速箱的输入轴被是以花键连接到从动片的轮毂上，离合器的接合提供发动机和变速箱之间的直接机械连结。,Transmissions,An engine develops a specific amount of torque at a given rpm point on its torque-brake horsepower curve. At low speeds, the torque is low. As the speed of the engine increases, the torque also increases, and it reaches a peak and begins to taper off before the maximum speed is reached. peak 顶点，最高峰，最高的 发动机在其制动扭功率曲线上的给定的转速点发出一定量的扭矩。在低速时，扭矩较低。随着发动机速度的增高，扭矩也在增加，而且当达到峰值后它将开始逐渐变小（达到最高速度之前）。,A three-speed standard synchromesh transmission is designed to develop great torque in fow gear in order to accelerate a vehicle quickly. However, the fow gear top speed is low. When the transmission is shift into second gear, greater speed and less torque are produced. In the third gear (direct drive), refatively fittle torque is produced at low speeds, but maximum engine speed is obtainable. synchromesh 同步啮合 标准的带同步器的三速速箱被设用来在低档时提高转矩来尽快的加速车辆。然而，低档时最高转速较低。当变速箱被换为二档时可以得到较高的转速和较低的扭矩。在三档（直接传动）时，在低转速得到相对较小的扭矩，但是可以获得发动机的最大转速。,Synchronizers are used to facilitate gear-shifting. They allow quicker shifts, reduce gear clashing, and permit downshifts while movting. Synchronizer has two brass blocking rings with teeth on their outer faces, two insert springs, three inserts, a special hub with teeth on its outer face, and a sleeve with internal teeth that mesh with the external teeth of the hub. The inside of each blocking ring has a beveled surface that slides against a similarly shaped surface on an output shaft gear. synchronizers 同步器；facilitate 使容易；brass 黄铜；springs 弹簧，发条； sleeve 跳，使跳跃； beveled 成斜角；similarly 同样地 用同步器可以使得换挡更容易。他们允许较快的换档，减少换档冲击，而且允许在盈动的情况下减档。同步器有两个外部带齿的闭合铜环，2个嵌入弹簧，3个衬套，1个特别的外部带齿的轮毂，和1个其内齿与轮毂的外齿相啮合的套筒。每个闭合铜环都有锥面并与输出轴齿轮上的类似的锥面相连。,The Driveshaft,The driveshaft of an automobile is designed to transmit torque from the transmission to the differential. When the rear wheels of a vehicle strike a bump, the wheels and the differential housing are pushed up. Since the engine and transmission are bolted more or less firmly in place, the angle through which the driveshaft operates must change in order to avoid damage to the shaft. Universaf joints, which allow the driveshaft to work at all angles, provide the necessary protection. strike 撞击，冲击，打击 汽车传动轴被设计用来传输从变速箱到差速器的扭矩。当车辆的后车轮遭受冲击，车轮差速器壳被向上推。由于发动机和变速在适当地位置上被或多或少紧固住，传动轴的角度必须能够改变以防止传动轴被损坏。可以允许传动轴在任何角度范围内工作的万向节提供了必需的保护。,Both standard and constant-velocity universal joints are used. Standard universal joints are employed at the front and rear of one-piece driveshafts, while constant-vefocity universal joints are used in the middle and at the front and/or rear of twoDiece driveshafts. A constant-velocity universal joint consists of two standard joints connected by a special link yoke. yoke轭，轭状的 实际中，标准万向节和等速万向节都有应用。标准万向节在一体式传动轴前端和后端都要采用，而等速万向节被用于组合式传动轴的中央和二体式传动轴的前端和后端，或任意一端。1个等速万向节由1个特别连杆叉和2个标准的连接体组成。,A geared differential is used to divide the output of a transmission between two drive wheels (usually the rear ones) and to enable the outer drive wheel to turn faster than the inner one when the vehicle turns a corner. The torque of the drive wheels and their speed relative to that of the driveshaft can be varied by using different gear ratios in the differential. 齿轮差速器将变速箱的输出2个驱动轮（通常是后轮）之间进行分配，当车辆转弯的时候使外部的驱动轮能够比内部的转的快些。在差速器中使用不同的传动比可以使驱动轮的扭矩和转速相对于传动轴产生相应的变化。,Differentials,For example, a ratio of 4.11 turns of the driveshaft to 1 turn of the drive wheels provides excellent power and acceleration because the torque multiplication of the differential allows the engine to reach peak torque output sooner.If the differential gear ratio is 3.00:1.00, the driveshaft will turn exactly 3 times for every turn of the drive wheel. Multiplicationb 乘法，增加 举例来，由于差速器的扭矩放大让发动机可以更快到达最高输出扭矩，4.11转的传动轴旋转对1转的驱动轮旋转可以提供令人满意的扭矩和车辆加速度。如果差遗器传动比是3.00;1.00l,传动轴转速刚好是驱动轮的三倍。,By comparison, the ratio of 4.11:1.00 results in more low speed torque,faster acceleration and greater fuel consumption, while the ratio of 3.00:1.00 procides a higher top speed better fuel economy. For best all-around operation, a differential gear ratio that provides a compromise between good mileage and brisk acceleration should be chosen In general, a ratio that falls between 2.75:1.00 and 3.00:1.00 achieves this compromise. consumption 消耗量；compromise 妥协， brisk 轻快的 通过比较，4.11:1.00的传动比产生较多的低速扭矩，比较快的加速度和比较多的燃料消耗量，而3.OO:1.OO的传动比可以提供比较高的车轮最高转速和较好的燃油经济性。为获得在全部运行环境下的最佳表现，差速器传动比的选择应当是在较好的每英里耗油量和轻松的加速度之间进行适当的协调。大体上，这种妥协选择在2.75：1 .00和3.00：100之间。,The Rear Axle,The rear axles of an automobile are usualIy enclosed by axle housing; but swing axles, which permit independent rear wheel suspension, operate in the open. swing 摇摆，摇动 汽车的后车桥通常被桥壳封闭；但是独立悬架的摇动式后车桥是开放式的。,Encfosed axles