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1、Gear Materials (Reading Material)齿轮材料（阅读材料）Gears are manufactured from a wide variety of materials, both metallic as well as nonmetallic.齿轮由多种种类的材料制造，包括金属材料和非金属材料。,As is the case with all materials used in design, the material chosen for a particular,gear should be the cheapest,available that will e
2、nsure satisfactory performance.在设计中可以使用多种材料的情况下，对于特定齿轮，应当做到选用满足使用要求下的最便宜的材料。Before a choice is made, the designer must decide which of several criteria is most important to the problem athand.在作出选择前，设计师必须决定在众多设计准则中哪个是当前最重要的。If high strength is the prime consideration, a steel should usually be chose
3、n rather than cast iron.如果高强度是第一要考虑的因素，通常就选择钢材而不选择铸铁。,If wear resistance is the most important consideration, a can be made, for problems involving noise,reduction,nonmetallic. Materials perform better than metallic ones.如果耐磨性是最重要的因素，可以选用非金属材料要比金属材料更好，同时也可以解决降低噪声的问题。However, as is true in most desig
4、n problems, the final choice of a material is usually a compromise.然而，在大部分实际设计问题中，对材料的最终决定往往是一个折衷的方案。In other words, the material chosen will conform reasonably well to all the requirements mentioned previously,although it will not necessarily be the best in any one area.,换句话说， 材料的选择要考虑到合理的达到所有的预定要求
5、，,尽管这样就不能在其中任何一方面达到最好。,To conclude this discussion we will consider the characteristics of various metallic and nonmetallic gear materialsaccording to their general classifications.为了总结这次讨论，我们将按照通常的分类来考虑多种金属和非金属齿轮材料所具有的特性。Cast Irons铸铁Cast iron is one of the most commonly used gear materials.铸铁是最常用的齿
6、轮材料之一。Its low cost, ease of casting, good machinability, high wear resistance, and good noise abatement property make ita logical choice.它具有低成本，铸造性好，机械加工性能好，高耐磨性，以及高减噪性的特点，这些特点使铸铁成为一个合适的选择对象。The primary disadvantage of cast iron as a gear material is its low tensile strength, which makes the gear to
7、othweak in bending and necessitates rather large teeth.铸铁主要的缺点是，作为一种齿轮材料，铸铁的抗拉强度很低，这使得轮齿的抗弯强度很弱而且不能造出很大的轮齿。Another type of cast iron is nodular iron, which is made of cast iron to which a material such as magnesium orcerium has been added.另一种类型的铸铁是球墨铸铁，是在普通铸铁中加入了镁或者铈制成的。The result of this alloying i
8、s a material having a much higher tensile strength while retaining the good wear andmachining characteristics of ordinary cast iron.这种合金的特点是既具有高的抗拉强度，又保持了普通铸铁的高耐磨性和优秀的机械加工性能。Very often the combination of cast iron gear and a steel pinion will give a well balanced design with regard to cost,strength,
9、 and wear.通常，铸铁大齿轮和钢制小齿轮的组合能够在成本、强度和耐磨性之间达到较好的平衡。问题补充： Steel gear are usually made of pain carbon steels or alloy steels.钢制齿轮通常由碳钢或者合金钢制造。They have the advantage, over cast iron, of higher strength without undue increase in cost.它们具有比铸铁更高的强度，同时又没有是成本过高的增加。However, they usually require heat treatment
10、 to produce a surface hard enough to give satisfactory resistance towear.然而，它们通常需要经过热处理，以生成表面的硬化层来达到足够的耐磨性。Unfortunately, the heat treatment process usually produces distortion of the gear, with the result that gear load isnot uniformly distributed across the gear tooth face.,不幸的是， 热处理过程通常会使齿轮发生扭曲和形
11、变，,这样齿轮上的载荷就不能均匀的分布到轮齿的表面。,Since alloy steels are subject to less distortion due to heat treatment than carbon steels, they are often chosen inpreference to the carbon steels.合金钢具有变形量小的特点，因此比碳钢更适合热处理，它们通常比碳钢使用的更多。Although it is not the purpose here to discuss the various heat treatment methods and t
12、heir effect on the propertiesof materials so treated, the designer should be aware ofpossible problems arising from the use of heat treated materials.尽管这里讨论的目的不是热处理的方法和这些方法在材料上产生的不同影响，设计师仍然应当认识到对不用热处理材料的选择可能带来的各种问题。Gears are often through-hardened by water or oil quenching in order to increase their
13、 resistance to wear.齿轮通常都要经过在油介质或者水介质中的整体淬火，以达到增加耐磨性的目的。If a low degree of hardness is satisfactory, through-hardening is probably the most desirable heat treatment processto be used because of its inexpensiveness.如果对强度的要求较低，整体淬火可能是最适当的热处理方法，因为它的花费不高。Case hardening is used for gear that require a ha
14、rd surface and for which good accuracy is not necessary.局部淬火使用在那些要求表面硬度较高的齿轮上，而且很难精确的达到。The case hardening process results in gears that have much harder surfaces than cores.局部淬火处理的齿轮具有比心部组织硬度高的表面硬度。The advantage of case hardening is that, while the surface becomes hard and wear resistant, the tough
15、nessassociated with the core remains.局部淬火的优点是，表面具有高硬度和高耐磨性的同时，心部组织仍然保留着较高的韧性。Carburizing, cyaniding, and induction hardening are some of the processes commonly used to produce the casehardening effect.碳化、氰化、感应淬火是局部淬火中经常使用的处理方法。If great accuracy is required, the gear must be ground.如果对齿轮有精度要求，齿轮就必须经过
16、磨削。For problems in which corrosion resistant surfaces are desirable, nitriding is the process most often used. However,nitriding is a relatively expensive process and is usedonly if other processes do not produce satisfactory results.对于表面有抗腐蚀性要求的齿轮，渗氮是最常用的方法。然而，渗氮是一种相对较昂贵的热处理方法，并且通常只在其它热处理方法无法满足要求时才
17、会使用。Flame hardening and induction hardening are the methods usually used to harden larger gears.,火焰淬火和感应淬火是经常在大型齿轮上使用的热处理方法。To sum up this discussion of specially heat treated steels, the designer should make use of carbon or alloy steelswithout special heat treatment if the relatively low surfaceha
18、rdening of these untreated materials is satisfactory.作为对特殊热处理钢材讨论的总结，设计师应当在未经热处理的低表面硬度材料能够满足使用要求时，使用不经过特殊热处理的碳钢或合金钢。As the hardness requirement increase, the heat treated steels should be considered, with the least expensive steelthat satisfies the strength and wear requirements beingchosen.随着硬度要求的增
19、加，应当考虑选择能够达到强度、耐磨性要求的最便宜的热处理钢材。Nonferrous Metals Gears have been manufactured of nonmetallic materials for many years.用非金属材料来制造齿轮已经有很长时间。Rawhide, nylon, various type of plastics, and so on, have been used. The advantages obtained by using thesematerials are quiet operation, internal lubrication, dam
20、pening ofshock and vibration, and manufacturing economy.,生牛皮、尼龙、各种塑料、以及其它材料都得到应用。这些材料的优点有,:静音操作、自润滑、减振性好、,以及加工制造经济性好。Their primary disadvantages are lower load carrying capacity and low heat conductivity, which results in heatdistortion of the teeth and many result in a serious weakening ofthe gear
21、teeth.它们的主要缺点是承载能力低和热传导性差，这些引起了轮齿的热变形和多种轮齿能力的降低。Recently thermoplastic resins, with glass-fiber reinforcement and a lubricant as additives, have been used as gearmaterials.最近，一种由玻璃纤维加固、并且带有自润滑剂的热塑性塑料，已经被用来做齿轮材料。The composite material has resulted in greater load carrying capacity, a reduced thermal
22、expansion, greater wearresistance and fatigue endurance.合成材料具有更好的承载能力，更低的热膨胀系数，更好的耐磨性和更好的抗疲劳性能。,问题补充： Nonferrous Metals Nonmetallic Materials,麻烦翻译达人了！,Copper, zinc, aluminum, and titanium and titanium are materials used to obtain alloys that are useful gearmaterials.铜、锌、铝和钛是经常使用在齿轮材料中的合金金属。The coppe
23、r alloys, known as bronzes, are perhaps the most widely used.铜合金，比如青铜，可能是应用最广泛的合金。They are useful in problems where corrosion resistance is important and also where large sliding velocities exist.它们用在要求有较高耐腐蚀性的情况，以及有较大滑动速度存在时。Because of their ability to reduce friction and wear, they are usually use
24、d as the material for making the wormwheel in a worm gear set.因为具有减摩性和耐磨性的性能，它们通常用来制作涡轮减速器中的涡轮。Aluminum and zinc alloys are used to manufacture gears by the diecasting process.铝和锌的合金用来在模铸法中制造齿轮。,;AG平台 https:/www.cuiyiqi.org AG平台;ag平台官网 https:/www.takhte.org ag平台官网;亚洲游戏ag https:/www.yonseicssa.org 亚洲
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