时间：2011-03-11 23:11来源：蓝天飞行翻译 作者：admin 点击：次
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cgs system. See centimeter-gram-second system. chafe. To wear something away by a rubbing action. chafer (aircraft tire component). Layers of rubberized fabric that wrap around the edges of the carcass plies and enclose the bead area of the tire. Chafers provide good chafe resistance between the tire bead and the wheel. chaff (radar countermeasure). A material used to confuse enemy radar. Chaff is made of thin strips of metal foil packaged in such a way that it can be ejected from an airplane. When the chaff is ejected, it spreads out in the air and makes a large radar return. chafing tape. A fabric tape used to cover edges of metal sheets, screw and rivet heads, and any surface discontinuity on an aircraft structure that is to be covered by aircraft fabric. Covering these parts with chafing tape prevents their rubbing holes in the fabric. chain gear. A form of toothed wheel, or sprocket, used to transmit motion from one shaft to another. Sprockets on both shafts are joined by a roller chain, and when one shaft is turned, the roller chain pulls the other shaft around. The rear wheel of a bicycle is driven by a roller chain passing over two chain gears. chain hoist. A form of tackle used in a shop to lift heavy weights. A chain hoist uses an endless loop of chain to rotate the drive gear in a planetary gear system. The chain that supports and lifts the load is pulled up by the driven gear in the planetary system. A chain hoist is sometimes called a chain block or a chain fall. chain reaction. A self-sustaining action in which one event causes other events of the same kind to happen. It is a chain reaction in nuclear fission that releases so much energy that a neutron is knocked out of the nucleus of an atom. This neutron knocks other neutrons out, and each of them knocks out still other neutrons. chamfer. A bevel cut on the edge of a piece of metal or plastic. Chamfered edges are more attractive than sharp edges, and they are less likely to cut a person who contacts the edge. chamfer (verb). The act of cutting a bevel on the edge of a piece of metal or plastic. chamfered edge. A beveled edge. chamfered point (threaded fastener). The point of a threaded fastener, such as a bolt or a screw, that is formed in the shape of a cone with its top cut off (a truncated cone). The distance across the flat point of the cone is usually slightly less than the minor diameter of the threads, the diameter of the bolt or screw, measured at the bottom of the threads. Chamfered points are used when easy entry into the hole for starting is important. chamfered tooth (timing device). A tooth of a gear that has had one of the edges of its point chamfered, or beveled. The chamfered edge identifies the tooth that must be meshed with marked teeth on the mating gear to properly time the mechanism driven by the gears. |
