机械系外文翻译及原文模板及写作要求-本部-2012-V1[1]1

1、0湖州师范学院湖州师范学院本科毕业论文外文翻译及原文的写作要求本科毕业论文外文翻译及原文的写作要求根据普通高等学校本科毕业设计（论文）指导的内容，特对外文文献翻译提出以下要求：一、翻译的外文文献总字符要求不少于 1 万（或翻译成中文后至少在 2000 字以上）。二、翻译的外文文献应主要选自学术期刊、学术会议的文章、有关著作及其他相关材料，应与毕业论文（设计）主题相关，并作为外文参考文献列入毕业论文（设计）的参考文献。并在中文译在中文译文末尾注明原文作者及出处文末尾注明原文作者及出处。 原文出处：期刊类文献书写方法：序号作者（不超过3人，多者用等或etal表示）.题（篇）名J.刊名:（版本）,出

2、版年,卷次（期次）: 起止页次.原文出处：图书类文献书写方法：序号作者.书名M.版本.出版地:出版者,出版年: 起止页次.原文出处：论文集类文献书写方法：序号作者.篇名C.论文集名.出版地:出版者，出版年: 起止页次.原文出处：学位论文类书写方法：序号作者.篇名D.出版地: 单位名称，年份.原文出处：电子文献类书写方法：序号主要责任者. 题名:其他题名信息文献类型标志/文献载体标志 出版地: 出版者，出版年（更新或修改日期）引用日期.获取和访问途径.三、中文译文的基本撰写格式为：1.题目：采用三号、黑体字、居中打印；前后各空 0.5 行2.摘要与关键词：“摘要”与“关键词”这几个字样采用宋体小

3、 4 号加粗，顶格写，后面内容采用宋体小 4 号字体，不加粗。3.标题一级标题：标题序号为 1 2 3 等；小 3 号字体，宋体/ Times new Roman，顶格，加粗，前后各空 0.5 行；二级标题：标题序号为 1.1 1.2 1.3 等；4 号字体，宋体/ Times new Roman，顶格，加粗； 前后不空行；三级标题：标题序号为 1.1.1 1.1.2 1.1.3 等；小 4 号字体，宋体/ Times new Roman，顶格，加粗；4.正文采用小四号、宋体/ Times new Roman 字，行间距为固定值 20 磅，标准字符间距。页边距为左3cm，右 2cm，上下各 2

4、.5cm，页面统一采用 A4 纸。英文原文如为 word 文档，请用罗马字体（Times new Roman）排版，段前空两格，全文两端对齐。1从正文开始编写页码，页码居中。四、封面格式统一制作（注：封面上的“翻译题目”指中文译文的题目），填充内容为加粗小三号楷体_GB2312，并按“封面、中文译文、外文原文”的顺序装订。正文表格和图片标题均采用 5 号字体，单倍行距，与表格（图片）及正文间均空 0.5 行；表格中文字采用小 5 号字体，单倍行距。表格一律采用三线表形式。页眉为：页眉为：“湖州师范学院本科毕业论文外文翻译”，字体为五号宋体，居中；页码位于页面下方，居中，从正文开始编写页码，为

5、1，2，。2 毕毕业业论论文文外外文文翻翻译译毕毕业业设设计计（论论文文）题题目目翻译题目翻译题目指翻译后的中文译文的题目指翻译后的中文译文的题目学学 院院信息与工程学院信息与工程学院专专 业业姓姓 名名班班 级级 学学 号号指导教师指导教师湖州师范学院本科毕业论文外文翻译0如何延长轴承寿命如何延长轴承寿命摘要：摘要： 自然界苛刻的工作条件会导致轴承的失效，但是如果遵循一些简单的规则，轴承正常运转的机会是能够被提高的。在轴承的使用过程当中，过分的忽视会导致轴承的过热现象，也可能使轴承不能够再被使用，甚至完全的破坏。但是一个被损坏的轴承，会留下它为什么被损坏的线索。通过一些细致的侦察工作，我们可

6、以采取行动来避免轴承的再次失效。关键词：关键词： 轴承；失效；寿命导致轴承失效的原因很多，但常见的是不正确的使用、污染、润滑剂使用不当、装卸或搬运时的损伤及安装误差等。诊断失效的原因并不困难，因为根据轴承上留下的痕迹可以确定轴承失效的原因。然而，当事后的调查分析提供出宝贵的信息时，最好首先通过正确地选定轴承来完全避免失效的发生。为了做到这一点，再考察一下制造厂商的尺寸定位指南和所选轴承的使用特点是非常重要的。1 轴承失效的原因轴承失效的原因在球轴承的失效中约有 40%是由灰尘、脏物、碎屑的污染以及腐蚀造成的。污染通常是由不正确的使用和不良的使用环境造成的，它还会引起扭矩和噪声的问题。由环境和污

7、染所产生的轴承失效是可以预防的，而且通过简单的肉眼观察是可以确定产生这类失效的原因。通过失效后的分析可以得知对已经失效的或将要失效的轴承应该在哪些方面进行查看。弄清诸如剥蚀和疲劳破坏一类失效的机理，有助于消除问题的根源。只要使用和安装合理，轴承的剥蚀是容易避免的。剥蚀的特征是在轴承圈滚道上留有由冲击载荷或不正确的安装产生的压痕。剥蚀通常是在载荷超过材料屈服极限时发生的。如果安装不正确从而使某一载荷横穿轴承圈也会产生剥蚀。轴承圈上的压坑还会产生噪声、振动和附加扭矩。类似的一种缺陷是当轴承不旋转时由于滚珠在轴承圈间振动而产生的椭圆形压痕。这种破坏称为低荷振蚀。这种破坏在运输中的设备和不工作时仍振动

8、的设备中都会产生。此外，低荷振蚀产生的碎屑的作用就象磨粒一样，会进一步损害轴承。与剥蚀不同，低荷振蚀的特征通常是由于微振磨损腐蚀在润滑剂中会产生淡红色。消除振动源并保持良好的轴承润滑可以防止低荷振蚀。给设备加隔离垫或对底座进行隔离可以减轻环境的振动。另外在轴承上加一个较小的预载荷不仅有助于滚珠和轴承圈保持紧密的接触，并且对防止在设备运输中产生的低荷振蚀也有帮助。造成轴承卡住的原因是缺少内隙、润滑不当和载荷过大。在卡住之前，过大的摩湖州师范学院本科毕业论文外文翻译1擦和热量使轴承钢软化。过热的轴承通常会改变颜色，一般会变成蓝黑色或淡黄色。摩擦还会使保持架受力，这会破坏支承架，并加速轴承的失效。材

9、料过早出现疲劳破坏是由重载后过大的预载引起的。如果这些条件不可避免，就应仔细计算轴承寿命，以制定一个维护计划。另一个解决办法是更换材料。若标准的轴承材料不能保证足够的轴承寿命，就应当采用特殊的材料。另外，如果这个问题是由于载荷过大造成的，就应该采用抗载能力更强或其他结构的轴承。蠕动不象过早疲劳那样普遍。轴承的蠕动是由于轴和内圈之间的间隙过大造成的。蠕动的害处很大，它不仅损害轴承，也破坏其他零件。蠕动的明显特征是划痕、擦痕或轴与内圈的颜色变化。为了防止蠕动，应该先用肉眼检查一下轴承箱件和轴的配件。蠕动与安装不正有关。如果轴承圈不正或翘起，滚珠将沿着一个非圆周轨道运动。这个问题是由于安装不正确或公

10、差不正确或轴承安装现场的垂直度不够造成的。如果偏斜超过 0.25，轴承就会过早地失效。检查润滑剂的污染比检查装配不正或蠕动要困难得多。污染的特征是使轴承过早的出现磨损。润滑剂中的固体杂质就象磨粒一样。如果滚珠和保持架之间润滑不良也会磨损并削弱保持架。在这种情况下，润滑对于完全加工形式的保持架来说是至关重要的。相比之下，带状或冠状保持架能较容易地使润滑剂到达全部表面。锈是湿气污染的一种形式，它的出现常常表明材料选择不当。如果某一材料经检验适合工作要求，那么防止生锈的最简单的方法是给轴承包装起来，直到安装使用时才打开包装。2 避免失效的方法避免失效的方法解决轴承失效问题的最好办法就是避免失效发生。

11、这可以在选用过程中通过考虑关键性能特征来实现。这些特征包括噪声、起动和运转扭矩、刚性、非重复性振摆以及径向和轴向间隙。扭矩要求是由润滑剂、保持架、轴承圈质量（弯曲部分的圆度和表面加工质量）以及是否使用密封或遮护装置来决定。润滑剂的粘度必须认真加以选择，因为不适宜的润滑剂会产生过大的扭矩，这在小型轴承中尤其如此。另外，不同的润滑剂的噪声特性也不一样。举例来说，润滑脂产生的噪声比润滑油大一些。因此，要根据不同的用途来选用润滑剂。在轴承转动过程中，如果内圈和外圈之间存在一个随机的偏心距，就会产生与凸轮运动非常相似的非重复性振摆（NRR） 。保持架的尺寸误差和轴承圈与滚珠的偏心都会引起 NRR。和重复

12、性振摆不同的是，NRR 是没有办法进行补偿的。在工业中一般是根据具体的应用来选择不同类型和精度等级的轴承。例如，当要湖州师范学院本科毕业论文外文翻译2求振摆最小时，轴承的非重复性振摆不能超过 0.3 微米。同样，机床主轴只能容许最小的振摆，以保证切削精度。因此在机床的应用中应该使用非重复性振摆较小的轴承。在许多工业产品中，污染是不可避免的，因此常用密封或遮护装置来保护轴承，使其免受灰尘或脏物的侵蚀。但是，由于轴承内外圈的运动，使轴承的密封不可能达到完美的程度，因此润滑油的泄漏和污染始终是一个未能解决的问题。一旦轴承受到污染，润滑剂就要变质，运行噪声也随之变大。如果轴承过热，它将会卡住。当污染物

13、处于滚珠和轴承圈之间时，其作用和金属表面之间的磨粒一样，会使轴承磨损。采用密封和遮护装置来挡开脏物是控制污染的一种方法。噪声是反映轴承质量的一个指标。轴承的性能可以用不同的噪声等级来表示。噪声的分析是用安德逊计进行的，该仪器在轴承生产中可用来控制质量，也可对失效的轴承进行分析。将一传感器连接在轴承外圈上，而内圈在心轴以 1800r/min 的转速旋转。测量噪声的单位为 anderon。即用 um/rad 表示的轴承位移。根据经验，观察者可以根据声音辨别出微小的缺陷。例如，灰尘产生的是不规则的劈啪声；滚珠划痕产生一种连续的爆破声，确定这种划痕最困难；内圈损伤通常产生连续的高频噪声，而外圈损伤则产

14、生一种间歇的声音。轴承缺陷可以通过其频率特性进一步加以鉴定。通常轴承缺陷被分为低、中、高三个波段。缺陷还可以根据轴承每转动一周出现的不规则变化的次数加以鉴定。低频噪声是长波段不规则变化的结果。轴承每转一周这种不规则变化可出现1.610 次，它们是由各种干涉（例如 轴承圈滚道上的凹坑）引起的。可察觉的凹坑是一种制造缺陷，它是在制造过程中由于多爪卡盘夹的太紧而形成的。中频噪声的特征是轴承每旋转一周不规则变化出现 1060 次。这种缺陷是由在轴承圈和滚珠的磨削加工中出现的振动引起的。轴承每旋转一周高频不规则变化出现60300 次，它表明轴承上存在着密集的振痕或大面积的粗糙不平。利用轴承的噪声特性对轴

15、承进行分类，用户除了可以确定大多数厂商所使用的ABEC 标准外，还可确定轴承的噪声等级。ABEC 标准只定义了诸如孔、外径、振摆等尺寸公差。随着 ABEC 级别的增加（从 3 增到 9） ，公差逐渐变小。但 ABEC 等级并不能反映其他轴承特性，如轴承圈质量、粗糙度、噪声等。因此，噪声等级的划分有助于工业标准的改进。From: Lin J., Lian R.J. Extending Bearing Life J. Journal of process Control, 2010, 20: 5-7.湖州师范学院本科毕业论文外文翻译0毕业设计（论文）外文翻译原文Extending Bearing

16、LifeAbstract：Nature works hard to destroy bearings, but their chances of survival can be improved by following a few simple guidelines. Extreme neglect in a bearing leads to overheating and possibly seizure or, at worst, an explosion. But even a failed bearing leaves clues as to what went wrong. Aft

17、er a little detective work, action can be taken to avoid a repeat performance.Keywords: Bearings; Failures; LifeBearings fail for a number of reasons，but the most common are misapplication，contamination，improper lubricant，shipping or handling damage，and misalignment. The problem is often not difficu

18、lt to diagnose because a failed bearing usually leaves telltale signs about what went wrongHowever，while a postmortem yields good information，it is better to avoid the process altogether by specifying the bearing correctly in The first placeTo do this，it is useful to review the manufacturers sizing

19、guidelines and operating characteristics for the selected bearing.Equally critical is a study of requirements for noise, torque, and runout, as well as possible exposure to contaminants, hostile liquids, and temperature extremes. This can provide further clues as to whether a bearing is right for a

20、job.1 Why bearings failAbout 40% of ball bearing failures are caused by contamination from dust, dirt, shavings, and corrosion. Contamination also causes torque and noise problems, and is often the result of improper handling or the application environmentFortunately, a bearing failure caused by env

21、ironment or handling contamination is preventable，and a simple visual examination can easily identify the cause.Conducting a postmortem il1ustrates what to look for on a failed or failing bearingThen，understanding the mechanism behind the failure, such as brinelling or fatigue, helps eliminate the s

22、ource of the problem.Brinelling is one type of bearing failure easily avoided by proper handing and assembly. It is characterized by indentations in the bearing raceway caused by 湖州师范学院本科毕业论文外文翻译1shock loadingsuch as when a bearing is dropped-or incorrect assembly. Brinelling usually occurs when loa

23、ds exceed the material yield point(350,000 psi in SAE 52100 chrome steel)It may also be caused by improper assembly, Which places a load across the racesRaceway dents also produce noise，vibration，and increased torque.A similar defect is a pattern of elliptical dents caused by balls vibrating between

24、 raceways while the bearing is not turningThis problem is called false brinelling. It occurs on equipment in transit or that vibrates when not in operation. In addition, debris created by false brinelling acts like an abrasive, further contaminating the bearing. Unlike brinelling, false binelling is

25、 often indicated by a reddish color from fretting corrosion in the lubricant.False brinelling is prevented by eliminating vibration sources and keeping the bearing well lubricated. Isolation pads on the equipment or a separate foundation may be required to reduce environmental vibration. Also a ligh

26、t preload on the bearing helps keep the balls and raceway in tight contact. Preloading also helps prevent false brinelling during transit.Seizures can be caused by a lack of internal clearance, improper lubrication, or excessive loading. Before seizing, excessive, friction and heat softens the beari

27、ng steel. Overheated bearings often change color，usually to blue-black or straw coloredFriction also causes stress in the retainer，which can break and hasten bearing failurePremature material fatigue is caused by a high load or excessive preloadWhen these conditions are unavoidable，bearing life shou

28、ld be carefully calculated so that a maintenance scheme can be worked outAnother solution for fighting premature fatigue is changing materialWhen standard bearing materials，such as 440C or SAE 52100，do not guarantee sufficient life，specialty materials can be recommended. In addition，when the problem

29、 is traced back to excessive loading，a higher capacity bearing or different configuration may be usedCreep is less common than premature fatigueIn bearingsit is caused by excessive clearance between bore and shaft that allows the bore to rotate on the shaftCreep can be expensive because it causes da

30、mage to other components in addition to the bearingOther more likely creep indicators are scratches，scuff marks，or discoloration to shaft and boreTo prevent creep damage，the bearing housing 湖州师范学院本科毕业论文外文翻译2and shaft fittings should be visually checkedMisalignment is related to creep in that it is m

31、ounting relatedIf races are misaligned or cockedThe balls track in a noncircumferencial pathThe problem is incorrect mounting or tolerancing，or insufficient squareness of the bearing mounting siteMisalignment of more than 1/4can cause an early failureContaminated lubricant is often more difficult to

32、 detect than misalignment or creepContamination shows as premature wearSolid contaminants become an abrasive in the lubricantIn addition。insufficient lubrication between ball and retainer wears and weakens the retainerIn this situation，lubrication is critical if the retainer is a fully machined type

33、Ribbon or crown retainers，in contrast，allow lubricants to more easily reach all surfacesRust is a form of moisture contamination and often indicates the wrong material for the applicationIf the material checks out for the job，the easiest way to prevent rust is to keep bearings in their packaging，unt

34、il just before installation2 Avoiding failuresThe best way to handle bearing failures is to avoid themThis can be done in the selection process by recognizing critical performance characteristicsThese include noise，starting and running torque，stiffness，nonrepetitive runout，and radial and axial playI

35、n some applications, these items are so critical that specifying an ABEC level alone is not sufficientTorque requirements are determined by the lubricant，retainer，raceway quality(roundness cross curvature and surface finish)，and whether seals or shields are usedLubricant viscosity must be selected c

36、arefully because inappropriate lubricant，especially in miniature bearings，causes excessive torqueAlso，different lubricants have varying noise characteristics that should be matched to the application. For example，greases produce more noise than oilNonrepetitive runout(NRR)occurs during rotation as a

37、 random eccentricity between the inner and outer races，much like a cam actionNRR can be caused by retainer tolerance or eccentricities of the raceways and ballsUnlike repetitive runout, no compensation can be made for NRR.NRR is reflected in the cost of the bearingIt is common in the industry to 湖州师

38、范学院本科毕业论文外文翻译3provide different bearing types and grades for specific applicationsFor example，a bearing with an NRR of less than 0.3um is used when minimal runout is needed，such as in diskdrive spindle motorsSimilarly，machinetool spindles tolerate only minimal deflections to maintain precision cutsC

39、onsequently, bearings are manufactured with low NRR just for machine-tool applicationsContamination is unavoidable in many industrial products，and shields and seals are commonly used to protect bearings from dust and dirtHowever，a perfect bearing seal is not possible because of the movement between

40、inner and outer racesConsequently，lubrication migration and contamination are always problemsOnce a bearing is contaminated, its lubricant deteriorates and operation becomes noisierIf it overheats，the bearing can seizeAt the very least，contamination causes wear as it works between balls and the race

41、way，becoming imbedded in the races and acting as an abrasive between metal surfacesFending off dirt with seals and shields illustrates some methods for controlling contaminationNoise is as an indicator of bearing qualityVarious noise grades have been developed to classify bearing performance capabil

42、itiesNoise analysis is done with an Anderon meter, which is used for quality control in bearing production and also when failed bearings are returned for analysis. A transducer is attached to the outer ring and the inner race is turned at 1,800rpm on an air spindle. Noise is measured in andirons, which represent ball displacement in m/rad.With experience, inspectors can identify the smallest flaw from their sound. Dust, for example, makes an irregular crackling. Ball scratches make a consistent popping and are the most difficult to identify. Inner-race damage is normally a constan