外文翻译--离合器工作原理

附 录 How Clutches Work If you drive a manual transmission car, you may be surprised to find out that it has more than one clutch. And it turns out that folks with automatic transmission cars have clutches, too. In fact, there are clutches in many things you probably see or use every day: Many cordless drills have a clutch, chain saws have a centrifugal clutch and even some yo-yos have a clutch. Clutch Image Gallery Diagram of car showing clutch location. See more clutch images In this article, youll learn why you need a clutch, how the clutch in your car works and find out some interesting, and perhaps surprising, places where clutches can be found. Clutches are useful in devices that have two rotating shafts. In these devices, one of the shafts is typically driven by a motor or pulley, and the other shaft drives another device. In a drill, for instance, one shaft is driven by a motor and the other drives a drill chuck. The clutch connects the two shafts so that they can either be locked together and spin at the same speed, or be decoupled and spin at different speeds. In a car, you need a clutch because the engine spins all the time, but the cars wheels do not. In order for a car to stop without killing the engine, the wheels need to be disconnected from the engine somehow. The clutch allows us to smoothly engage a spinning engine to a non-spinning transmission by controlling the slippage between them. To understand how a clutch works, it helps to know a little bit about friction, which is a measure of how hard it is to slide one object over another. Friction is caused by the peaks and valleys that are part of every surface - even very smooth surfaces still have microscopic peaks and valleys. The larger these peaks and valleys are, the harder it is to slide the object. You can learn more about friction in How Brakes Work. A clutch works because of friction between a clutch plate and a flywheel. Well look at how these parts work together in the next section. Fly Wheels, Clutch Plates and Friction In a cars clutch, a flywheel connects to the engine, and a clutch plate connects to the transmission. You can see what this looks like in the figure below. When your foot is off the pedal, the springs push the pressure plate against the clutch disc, which in turn presses against the flywheel. This locks the engine to the transmission input shaft, causing them to spin at the same speed. Pressure plate The amount of force the clutch can hold depends on the friction between the clutch plate and the flywheel, and how much force the spring puts on the pressure plate. The friction force in the clutch works just like the blocks described in the friction section of How Brakes Work, except that the spring presses on the clutch plate instead of weight pressing the block into the ground. When the clutch pedal is pressed, a cable or hydraulic piston pushes on the release fork, which presses the throw-out bearing against the middle of the diaphragm spring. As the middle of the diaphragm spring is pushed in, a series of pins near the outside of the spring causes the spring to pull the pressure plate away from the clutch disc (see below). This releases the clutch from the spinning engine. Common Problems From the 1950s to the 1970s, you could count on getting between 50,000 and 70,000 miles from your cars clutch. Clutches can now last for more than 80,000 miles if you use them gently and maintain them well. If not cared for, clutches can start to break down at 35,000 miles. Trucks that are consistently overloaded or that frequently tow heavy loads can also have problems with relatively new clutches. Photo courtesy Carolina Mustang Clutch plate The clutch only wears while the clutch disc and the flywheel are spinning at different speeds. When they are locked together, the friction material is held tightly against the flywheel, and they spin in sync. Its only when the clutch disc is slipping against the flywheel that wearing occurs. So, if you are the type of driver who slips the clutch a lot, youll wear out your clutch a lot faster. Sometimes the problem is not with slipping, but with sticking. If your clutch wont release properly, it will continue to turn the input shaft. This can cause grinding, or completely prevent your car from going into gear. Some common reasons a clutch may stick are: Broken or stretched clutch cable - The cable needs the right amount of tension to push and pull effectively. Leaky or defective slave and/or master clutch cylinders - Leaks keep the cylinders from building the necessary amount of pressure. Air in the hydraulic line - Air affects the hydraulics by taking up space the fluid needs to build pressure. Misadjusted linkage - When your foot hits the pedal, the linkage transmits the wrong amount of force. Mismatched clutch components - Not all aftermarket parts work with your clutch. A hard clutch is also a common problem. All clutches require some amount of force to depress fully. If you have to press hard on the pedal, there may be something wrong. Sticking or binding in the pedal linkage, cable, cross shaft, or pivot ball are common causes. Sometimes a blockage or worn seals in the hydraulic system can also cause a hard clutch. Another problem associated with clutches is a worn throw-out bearing, sometimes called a clutch release bearing. This bearing applies force to the fingers of the spinning pressure plate to release the clutch. If you hear a rumbling sound when the clutch engages, you might have a problem with the throw-out. Types of Clutches There are many other types of clutches in your car and in your garage. An automatic transmission contains several clutches. These clutches engage and disengage various sets of planetary gears. Each clutch is put into motion using pressurized hydraulic fluid. When the pressure drops, springs cause the clutch to release. Evenly spaced ridges, called splines, line the inside and outside of the clutch to lock into the gears and the clutch housing. You can read more about these clutches in How Automatic Transmissions Work. An air conditioning, compressor in a car has an electromagnetic clutch. This allows the compressor to shut off even while the engine is running. When current flows through a magnetic coil in the clutch, the clutch engages. As soon as the current stops, such as when you turn off your air conditioning, the clutch disengages. Most cars that have an engine-driven cooling fan have a thermostatically controlled viscous clutch - the temperature of the fluid actually drives the clutch. This clutch is positioned at the hub of the fan, in the airflow coming through the radiator. This type of clutch is a lot like the viscous coupling sometimes found in all-wheel drive cars. The fluid in the clutch gets thicker as it heats up, causing the fan to spin faster to catch up with the engine rotation. When the car is cold, the fluid in the clutch remains cold and the fan spins slowly, allowing the engine to quickly warm up to its proper operating temperature. Many cars have limited slip differentials or viscous couplings, both of which use clutches to help increase traction. When your car turns, one wheel spins faster than the other, which makes the car hard to handle. The slip differential makes up for that with the help of its clutch. When one wheel spins faster than the others, the clutch engages to slow it down and match the other three. Driving over puddles of water or patches of ice can also spin your wheels. You can learn more about differentials and viscous couplings in How Differentials Work. Gas-powered chain saws and weed eaters have centrifugal clutches, so that the chains or strings can stop spinning without you having to turn off the engine. These clutches work automatically through the use of centrifugal force. The input is connected to the engine crankshaft. The output can drive a chain, belt or shaft. As the rotations per minute increase, weighted arms swing out and force the clutch to engage. Centrifugal clutches are also often found in lawn mowers, go-karts, mopeds and mini-bikes. Even some yo-yos are manufactured with centrifugal clutches. Clutches are valuable and necessary to a number of applications. For more information on clutches and related topics, check out the links on the following page. 离合器工作原理 如果您驾驶手动变速箱的汽车，您可能会惊讶地发现，它有一个以上的离合器。事实证明，与自动变速器汽车离合器相比，有许多种类离合器在你可能看到或每天使用：许多无绳演习有离合器，链锯有离心离合器，甚至一些部件也有一个离合器。 Diagram of car showing clutch location. See more clutch images. 在本文中，您会了解为什么你需要一个离合器，在您的汽车离合器工程和一些有趣的发现，也许不足为奇。 离合器是有用的设备，有两个旋转轴。在这些设备中，其中一个轴通常是驱动马达或滑轮，其他轴驱动其他设备。例如，一轴驱动 电机和其他驱动钻夹头。离合器连接从动盘和压盘，以便它们可以被贴在一起，旋转同样的速度，或脱钩，并以不同的速度旋转。 在汽车中，您需要一个离合器，因为发动机的转速所有的时间中，但并不是所有的时间都传递动力。为了让汽车停止传递动力不造成发动机过载，车轮需要断开发动机传递动力。离合器使我们能够顺利地进行旋转发动机的非线性传递，通过控制离合器压盘与摩擦片之间的滑动。 了解离合器的特点，它有助于了解一点摩擦片，这是衡量离合器的标准。摩擦所造成的传力高峰和低谷的每一部分，每一个平面 -甚至是非常平滑的表面仍然有微小的高峰 和低谷。这些较大的高峰和低谷，就是摩擦片研究的对象。您可以了解更多关于离合器如何摩擦工作。 离合器的工作，产生于摩擦离合器压盘和飞轮。我们将探讨如何共同工作，这些零件将在下面介绍。 飞轮，离合器片和摩擦在汽车的离合器，一个飞轮连接到发动机，离合器踏板连接传输。 当你的脚离开踏板，弹簧推动压力板对离合器盘，而这反过来压力又回位。这种转速控制包括发动机，变速器输入轴，使他们自旋同样的速度。 压盘 离合器传递的动力取决于摩擦离合器盘和飞轮，有多少转矩通过飞轮压盘传递给膜片弹簧。摩擦离合器作用就像 描述的摩擦制动器的工作一样，但弹簧压力离合器压盘不是像制动器那样依靠抱紧制动盘。 当离合器踏板被踏下时，机械或液压活塞推动拨叉，这些压力通过分离轴承对中间的膜片弹簧起作用。把膜片弹簧是推离了压盘的附近达到让离合器分离的效果。 请注意弹簧离合器从动盘。这些弹簧有助于缓解传输的过大动力冲击离合器盘毂。这种设计通常非常有效，但它确实有一些缺点。让我们分别看看离合器问题和其他用途的离合器在以下的内容中讲解。 从动盘 常见问题： 从 20 世纪 50 年代到 20 世纪 70 年代，你可以指望得到 5 万至七万里程汽车的离合器。离 合器现在可以超过去年八点零零零万英里如果您使用它们轻轻地和维持好。如果不是照顾，离合器就可以开始打破在 35000 英里。卡车一贯超载或经常拖重物，也可以有问题相对较新的离合器。 最常见的问题是，离合器摩擦材料的磨损。摩擦材料在离合器盘非常相似的摩擦材料的垫片的盘式制动器的鼓式制动器 -过了一段时间，它磨穿了。当大部分或全部的摩擦材料已经一去磨损了了，离合器效率将开始下滑，并最终将不会传送任何转矩从发动机到车轮。 离合器只能传送离合器盘和飞轮的旋转速度不同。当他们被锁在一起，摩擦材料是紧密举行接合与飞轮 ，他们自旋同步。只有当离合器盘下滑对飞轮的穿着发生。因此，如果您是一个司机，踩离合器的次数多，您的离合器磨损快得多。 有时，问题不在于传递的摩擦力下滑，但问题是。如果您的离合器装配不正确，它将继续联入输入轴。这可能会导致磨，或完全防止您的车进入齿轮。一些常见的原因可能导致离合器出问题： 损坏或拉伸离合器拉线 -拉线需要适量的张紧力。 液压泵有缺陷 /或主离合器液压瓶 -泄漏保持液压瓶必须建立必要的压力。 空气中的气压线 -空气影响液压，空气流体需要建立适当压力。 不匹配的离 合器组件 -并非所有的售后配件与您的离合器能匹配。 “ 硬 ” 离合器也是一种常见的问题。所有离合器需要一些相应的转矩范围。如果您必须紧逼踏板上，可能会有一些错误的。坚持或有约束力的踏板联系，电缆，交叉轴或旋转球的常见原因。有时堵塞或磨损在液压系统也可能导致硬离合器。 另一个问题与离合器是一个破旧投掷出轴承，有时称为离合器释放轴承。以手