自动变速器汽车车辆类课程毕业设计外文文献翻译@中英文翻译@外文翻译VIP

1 自动变速器 现代自动变速箱是当今汽车迄今为止 ,最复杂的机械组件 .自动变速器包含机械系统、液压系统、电气系统和计算机控制 .它们 几乎 无声地完美和谐的工作在 一起 ,直到 出现 问题 . 这篇文章将帮助您了解这些技术奇 迹 背 念 ，让你进入当它们工作出在问题如何修复的天地 . 这篇文章分为 四 个部分 : 什么是变速器损坏在 最简单的条件 下，变速器的用途是什么 . 在他们变得更坏前发现问题，展示如何寻找并 防止小问题变成大问题 . 维修 谈大家也 应该知道 的 预防性维修 . 变速器 修理描述典型地执行在 变速器 从较小调整完成检修的修理形式。 什么是变速器 ? 变速器 是一个连接到背面 发动机 ,并将 动 力 从发动机传到 驱动车轮 的装置 . 汽车 发动机工作在 它最佳 的一 些 转速 (转每分钟 ) 范围 内，而变速器的工作就是在发动机转速在一定范围内确保动力被分到各个轮子 .这个通过 各种齿轮组合 来实现的 . 在一档里 , 发动机 快速转动 传到 驱动轮 ，而 在高 挡时发动机空转， 即使汽车 可能行驶 超出 70 里 /时。除各种各样的 前进 齿轮之外 ,变速器也有一个 并 没有连接 从驱动轮 到发动机 的中性位置 , 并且相反 ,能使驱动轮相反转动允许你倒退 。 最后，是停车位置 。在这个位置 , 门闩 机制 (不似一个非螺栓 锁 住 门 ) 被插入入一个槽孔在输出轴 去锁住 驱动轮和保 持它 们转动 , 从而防止车辆滚动 .。 有两个基本类型的汽车自动变速器基于是否后轮驱动或前轮驱动 . 对后轮驱动汽车，变速器通常安装到后面的发动机和位于地板的中心沿着油门踏板位置 .一根传动轴连接变速器后方到位于后车轴被用来传递动力到后轮的主减速器 . 动力流在这个系统是从引擎简单和直接向前传递 , 通过 2 扭矩交换器 ,然后通过变速器和传动 轴直到到达主减速器，分散开传到两个后轮 . 对前轮驱动汽车，变速器通常由一根传动轴与主减速器结合起来 .发动机在前轮驱动车上通常安装在汽车上的侧身和传动轴下面发动机的一侧面面向汽车后方 .前轴直接与传动轴相连，提供动力给前轮 .这个例子 ,动力从发动机，通过变矩器传递到一个大链子能够传递动力通过转 180 度到发动机侧面的变速器 .从那里 ,动力路线通过变速器到主减速器，通过驱动轴分散开传到两个前轮 . 还有一些其他的布置包括前面驱动发动机安装由前至后代替侧方 ,还有其他所有四轮驱动但这里所说的两个系统是目前最常用的 .较为冷门后 轮驱动，发动机在后方直接安装到主减速器通过一个驱动轴连接到还安放在发动机的变矩器 . 这个系统被发现在护卫舰和被使用是为了平衡前轮和后轮的重量去改进性能和处理 .另一个后轮驱动系统安装一切，发动机，变速器和主减速器在后方 . 发现问题在它们变得更坏之前 在汽车下寻找 泄漏或污点 如果有一个 红色 持续漏油 那 一定 是 来自你的车 ,你应该 去车 店看看它 是否 来自你 的变速器 或 可能从动 力转向系统 (大部分 动 力转向系统还利用 变速器液 及泄漏可能大致出现在地面 同一 区域和 变速器 泄漏一样。 ). 如果 所有你看见 的 是几下落在地面 ,你 可 能 会 延缓维修只要 你 经常检查液面 (但 同 你 的 技术员 检查 确定下 ).变速器液面 若低于最低水平 变速器会 严重损坏 (相同 建议同动 力转向外泄 ). 检查 液体 颜色 ,气味 多数厂商要求你检查 变速器液面水平 当汽车在平坦的地面 行驶 . 拔出 变速器 量油计 ， 检查流体颜色和气味。 变速器流体 是 看起来像一种 咳嗽糖浆的红色透明油 .如果液体 变灰 ,有恶臭或烧毁 ,你 就 应该 让 你的技术员 去检查一下可以 提醒你 液体 流失和再装满或调节。 维修下一节 将 详细 说明 这项服务 . 对新噪声、振动和转移行为是敏感的 现代 变速器 应该在轻的加速度之下顺利地和安静地转移。 3 更重的加速度会在更高的速度下产生更加牢固的转移 . 如果转移点 有 古怪的或当转移 时你 听见噪声 , 你 应该立刻安排检查。 噪声来自地板 的 噪声 也是一件 令人担心的事 如果发现得早， 许多问题能 在不发费 昂贵的 变速器 检修解决。既使 这次你不能支付 得起修理 , 你 至少 要 检查 下 。技术员可以给你一些 什么该做什么不该做来 延长 变速器寿 命 ,直到你 付 得起修理 费的启示 . 维护 变速器油应该 定期更换 .你的汽 车 手册应该给你推荐 更换间隔从 15000英里到十万英里 .大多数 变速器 专家建议每 25000 英里 更换一次 流体及过滤 . 少数变速器有 放油螺塞 排 出 旧液 .为了让 油液排出 ,技术员 移 除 变速器 油底壳 .这是一个相当凌乱的工作 ,一般不 推荐自己弄 .即使 变速器有 放油螺塞 ，唯一方式也是改变变速器过滤器去移开 油底壳 .当 移开 油底壳 后 ,技术员可以查 看 金属屑等杂物所 引起的变速器 问题 . 变速器修理 调整和汽车修理 有几个问题是可以 通过调整 解 (一个简单的调整 可以在不移动汽车变速器下进行 )或 小 修 来解决 . 如果晚式样 变速器 (电脑控制变速器在九十年代初开始成为热门 )没有 转移好 ,结果往往是电脑由于传感器失灵发送了错误的信号 ,或 变速器 由于衔接不良或瑕疵螺线管叠板对计算机命令 没有 反应。这些问题可 以 被纠正当汽车变速器用 较少 的 钱 进行 完全检修 . 如果是非计算机控制 的变速器 太早或太晚 地转移 ,它可能需要一个调整的油门 拉索 .由于很少油门 拉索 自行调整或 者 因 为 磨损 ， 这些错误通常是由于其它一次故障的 重修 工作 或 损坏引起的 .如果汽车 有 真空调制器代替了油门拉索 ,就有一个调整 ,被制成用来 一些调制设计 的 调整螺丝 .在车辆加装调制器 ,但它 在 有没有真空 泄漏 和发动机 能否 高效率运行 方面很重要 .真空发动机对 发动机是如何运行 是非常敏感敏感的 . 实际上 , 许多技术员使用真空测量 4 仪诊断性能问题和状态定调 .很多问题似乎是 变速器问题在一个调节后消失或者 发动机相关修理 已经 完成 . 在一些老 式的变速器， 可以 用带 调整来解决 打 滑 的 情况 .打滑是当变速器换挡从一个挡到下一个挡 发动机 短暂转动引起的 .但这没有对离合器盒 调整 . 重新密封工作 变速器 被重新密封为了修 复 外在 变速器 流体泄漏。如果 你 看 车下地面上的 红色油斑点 ，那么 你的变速器可能得进行 重新密封工作 . 为了检查 变速器泄漏 , 技术员把汽车放在 升降机 上研究油外泄迹象。 如果泄漏被察觉在任何外在 密封圈 或垫圈 使变速器没有运行 好 ,好术员很可能 会 推荐 , 变速器 被重新密封。 大多外在 密封 能被替换当 变速器还 在汽车 上 , 如果前面 密封 必须被替换 , 变速器 必须 首先 从车 上取下为了 对它能够 获取 , 这样做是 一个更加昂贵的工作 . 可更换零件 有一些地方 ,方便无需 移除变速器 .大部分 控制部分包括大部分电气 部分都是移掉 油底壳 进行修理 .这些 部分相连 ,然而不 同于变速器到变速器 ,大部分变速器修理厂不愿意提供有意义的保证在外在修理在普通季节他们不能发现是否还有另外的内部问题在 组件 里，只是接收变速器搬动 . 完成大修 在一次 完全检修 (亦称重 造变速器 ), 变速器 被从 汽车上移 除和完全地被拆卸 成 零件在工作计划 上 。每部分磨损和损坏 ,然后 用 一个特殊的清洁液清洗 ,或 根据 自己的条件更换另一部分 . 有摩擦表面的部份 , 譬如带和离合器象所有 密封 和垫圈 进行 替换。变矩器也 被 取代 ， 通常 和 改制 的一个 .技术服务公告被检查看如果汽车制造厂推荐 的 任 何修改 去纠 正 在变速器安装后 被发现的设计瑕疵。汽车厂家常常把升级套件用来解决这些 变速器厂的 设计缺陷 . 5 Automatic Transmissions by Charles Ofria The modern automatic transmission is by far, the most complicated mechanical component in todays automobile. Automatic transmissions contain mechanical systems, hydraulic systems, electrical systems and computer controls, all working together in perfect harmony which goes virtually unnoticed until there is a problem. This article will help you understand the concepts behind what goes on inside these technological marvels and what goes into repairing them when they fail. This article is broken down into five sections: What is a transmission breaks down in the simplest terms what the purpose of a transmission is. Spotting problems before they get worse shows what to look for to prevent a minor problem from becoming major. Maintenance talks about preventative maintenance that everyone should know about. Transmission repairs describes the types of repairs that are typically performed on transmissions from minor adjustments to complete overhauls. 6 What is a transmission? The transmission is a device that is connected to the back of the engine and sends the power from the engine to the drive wheels. An automobile engine runs at its best at a certain RPM (Revolutions Per Minute) range and it is the transmissions job to make sure that the power is delivered to the wheels while keeping the engine within that range. It does this through various gear combinations. In first gear, the engine turns much faster in relation to the drive wheels, while in high gear the engine is loafing even though the car may be going in excess of 70 MPH. In addition to the various forward gears, a transmission also has a neutral position which disconnects the engine from the drive wheels, and reverse, which causes the drive wheels to turn in the opposite direction allowing you to back up. Finally, there is the Park position. In this position, a latch mechanism (not unlike a deadbolt lock on a door) is inserted into a slot in the output shaft to lock the drive wheels and keep them from turning, thereby preventing the vehicle from rolling. There are two basic types of automatic transmissions based on whether the vehicle is rear wheel drive or front wheel drive. On a rear wheel drive car, the transmission is usually mounted to the back of the engine and is located under the hump in the center of the floorboard alongside the gas pedal position. A drive shaft connects the rear of the transmission to the final drive which is 7 located in the rear axle and is used to send power to the rear wheels. Power flow on this system is simple and straight forward going from the engine, through the torque converter, then through the transmission and drive shaft until it reaches the final drive where it is split and sent to the two rear wheels. On a front wheel drive car, the transmission is usually combined with the final drive to form what is called a transaxle. The engine on a front wheel drive car is usually mounted sideways in the car with the transaxle tucked under it on the side of the engine facing the rear of the car. Front axles are connected directly to the transaxle and provide power to the front wheels. In this example, power flows from the engine, through the torque converter to a large chain that sends the power through a 180 degree turn to the transmission that is along side the engine. From there, the power is routed through the transmission to the final drive where it is split and sent to the two front wheels through the drive axles. There are a number of other arrangements including front drive vehicles where the engine is mounted front to back instead of sideways and there are other systems that drive all four wheels but the two systems described here are by far the most popular. A much less popular rear drive arrangement has the transmission mounted directly to the final drive at the rear and is connected by a drive shaft to the torque converter which is still mounted on the engine. This system is found on the new Corvette and is used in order to balance the weight 8 evenly between the front and rear wheels for improved performance and handling. Another rear drive system mounts everything, the engine, transmission and final drive in the rear. Spotting problems before they get worse Watch for leaks or stains under the car If there is a persistent red oil leak that you are sure is coming from your car, you should have your shop check to see if it is coming from your transmission or possibly from your power steering system (most power steering systems also use transmission fluid and leaks can appear on the ground in roughly the same areas as transmission leaks.) If all you see is a few drops on the ground, you may be able to postpone repairs as long as you check your fluid level often (but check with your technician to be sure.) If transmission fluid levels go down below minimum levels serious transmission damage can occur (the same advice goes for power steering leaks as well.) Check fluid for color and odor Most manufacturers require that you check transmission fluid levels when the vehicle is running and on level ground. Pull the transmission dipstick out and check the fluid for color and odor. Transmission fluid is a transparent red oil that looks something like cherry cough syrup. If the fluid is cloudy or muddy, or it has a burned odor, you should have it checked by your technician who will most likely advise you to have a transmission drain and refill or transmission tune-up. See the Maintenance section below for details on this service. be sensitive to new noises, vibrations and shift behavior A modern transmission should shift smoothly and quietly under light acceleration. Heavier acceleration should produce 9 firmer shifts at higher speeds. If shift points are erratic or you hear noises when shifting, you should have it checked out immediately. Whining noises coming from the floorboard are also a cause for concern. If caught early, many problems can be resolved without costly transmission overhauls. Even if you feel that you cant afford repairs at this time, you should at least have it checked. The technician may be able to give you some hints on what to do and not do to prolong the transmission life until you can afford the repair. Maintenance Transmission fluid should be changed periodically. Your owners manual should give you the recommended intervals which could be anywhere from 15,000 miles to 100,000 miles. Most transmission experts recommend changing the fluid and filter every 25,000 miles. Few transmissions have drain plugs to drain the old fluid. In order to get the fluid out, the technician removes the transmission oil pan. This is quite a messy job and generally not recommended for the casual do-it-yourselfer. Even if the transmission has a drain plug, the only way to also change the transmission filter is to remove the pan. When the pan is down, the technician can check for metal shavings and other debris which are indicators of impending transmission problems. Transmission repairs. Adjustments and In-Car Repairs There are several problems that can be resolved with an adjustment (A simple adjustment is one that can be made without removing the transmission from the vehicle.) or minor repair. 10 If a late model transmission (computer-controlled transmissions started becoming popular in the early 90s) is not shifting properly, it is often the result of a computer sending incorrect signals due to a faulty sensor, or the transmission is not reacting to the computer command because of a bad connection or defective solenoid pack. These problems can be corrected while the transmission is in the car for considerably less money then a complete overhaul. If a non computer-controlled transmission is shifting too early or too late, it may require an adjustment to the throttle cable. Since throttle cables rarely go out of adjustment on their own or due to wear and tear, these mis-adjustments are usually due to other repair work or damage from an accident. If the vehicle has a vacuum modulator instead of a throttle cable, there is an adjustment that can be made using an adjustment screw in some modulator designs. In vehicles with modulators, however, it is very important that there are no vacuum leaks and the engine is running at peak efficiency. Engine vacuum is very sensitive to how well the engine is running. In fact, many technicians use a vacuum gauge to diagnose performance problems and state-of-tune. Many problems that seem to be transmission problems disappear after a tune-up or engine performance related repair was completed. In some older transmissions, bands can be adjusted to resolve slipping conditions. Slipping is when an engine races briefly when the transmission shifts from one gear to the next. There are no adjustments for clutch packs however. Reseal job A transmission is resealed in order to repair external 11 transmission fluid leaks. If you see spots of red oil on the ground under the car, your transmission may be a candidate for a reseal job. In order to check a transmission for leaks, a technician will put the car on a lift and examine the unit for signs of oil leaks. If a leak is spotted at any of the external seals or gaskets and the transmission otherwise performs well, the technician will most likely recommend that the transmission be resealed. Most of the external seals can be replaced while the transmission is still in the car but, if the front seal must be replaced, the transmission must first be removed from the vehicle in order to gain access to it, making it a much