英语翻译

第一课

设计实践可能是一个最令人兴奋的活动和履行工程师可以承担。有一种强烈的满足感和自豪感在看到自己的创造努力结果出现在实际产品和过程中受益的人。做设计也需要大量的特点。

the design engineer should not only have adequate technical training, but must be a person of sound judgment and wide experience, qualities which are usually acquired only after considerable time has been spent in actual professional work设计工程师不仅要有足够的技术训练，但必须是一个健全的判断力和广泛的经验，这些特质通常只能在相当长的时间后已被用在专业实际工作

a start in this direction can be made with a good teacher while the student is still at the university当学生仍在大学时，一个方向的开始可以由一个好的老师做出。

however, the beginning designer must expect to get a substantial portion of this training after leaving school through further reading and study, and especially by being associated with other competent engineers.然而，开始设计师必须指望得到相当一部分这种培训学校毕业后通过深入的阅读和研究，尤其是与其他主管工程师。

the more any one engineer knows about all phrases of design, the better.任何一个工程师更了解所有词组的设计，更好的。

design is an exacting profession, but highly fascinating when practiced against a broad background of knowledge.设计是一个严格的行业，但非常高质量的练习对着广泛的知识背景。

第三课

a gear having tooth elements that are straight and parallel to its axis is known as a spur gear一个齿轮的牙齿元素有直平行轴的被称为直齿轮。

a spur pair can be used to connect parallel shafts only.一对直齿轮只可以用来连接平行轴。

 parallel shafts, however, can also be connected by gears of another type, and a spur gear can be mated with a gear of a different type.平行轴上，然而，也可以被另一种类型的齿轮连接，以及直齿轮可以配对一种不同类型的齿轮。

helical gears have certain advantages螺旋齿轮上有一定的优势

for example, when connecting parallel shafts they have a higher load-carrying capacity than spur gears with the same tooth numbers and cut with the same cutter

例如，当连接平行轴，他们有较高的承载能力比直齿轮齿数相同，具有相同的刀

helical gears can be also be used to connect nonparallel, non-intersecting shafts at any angle to one another。斜齿轮也可以用来连接不平行、相交的轴，在任何角度彼此

ninety degrees is the most common angle at which such gears are used.九十度是最常见的角度，这样使用的齿轮

worm gears provide the simplest means of obtaining large ratios in a single pair蜗杆齿轮提供的最简单的方式获得大的比例在一个单一的一对

they are usually less efficient than parallel shaft gears, however, because of an additional sliding movement along the teeth.他们通常是效率较低的比平行轴齿轮，然而，因为另外一个沿牙齿滑动

 because of their similarity, the efficiency of a worm and gear depends on the same factors as the efficiency of a screw因为它们的相似性，蜗杆和齿轮的效率取决于同一因素，如螺杆的效率。

第四课

a bearing is a connector that permits the connected members to either rotate or translate (more to and from) relative to one another but prevents them from separating in the direction in which loads are applied

轴承是一个连接器，允许连接的成员或旋转或翻译（以上和从）相对彼此，但阻止它们分开的方向，负载的应用

in many cases one of the members is fixed, and the bearing acts as a support for the moving member

在许多情况下，一个成员是固定的，与轴承作为支承运动件

sliding bearing are the simplest to construct and, considering the multitude of pin-jointed devices and structures in use, are probably the most commonly used

滑动轴承是最简单的建设，考虑到众多的枢接装置和结构中使用，可能是最常用的

the essential parts of a ball bearing the inner and outer ring, the balls, and the separetor

一个球轴承的关键部件是内圈和外圈，球，和分离器

the inner ring is mounted on a shaft and has a groove in which the balls ride

内环是安装在轴和该球的一槽内的

the outer ring is usually the stationary part of the bearing and also contains a groove to guide and support the balls

外环通常是固定轴承的一部分，也包含一个槽引导和支持球

the separator prevents contact between the balls and thus reduces friction, wear, and noise from the regions where sliding conditions would occur

分离器防止球之间的接触，从而减少摩擦，磨损，噪音从地区会出现滑动条件

第五课

similar to an offset in that the cutting-plane line staggers, however, it differs in that the cutting-plane line is offset at some angle other than 90. When the section is taken the sectional view is drawn as if the cutting-plane is rotated to the plane perpendicular to the line of sight. This is why the right side sectional view may sometimes be elongated （depending on the shape）

类似的偏移量，切割面线蹒跚，然而，它的不同的切割面线偏移一定角度比其他90。当部分采取剖视图的绘制为如果切割平面旋转平面垂直于视线。这就是为什么对侧视图有时可能是拉长（基于不同的形状）

练习：

drawing the front view to aligned section绘制前视图对齐部分

the fig.5.4 is the topic and fig.5.5 is the answer fig.5.4是主题和fig.5.5就是答案

第六课

AutoCAD是一个计算机辅助绘制和设计系统应用于一台个人电脑。它支持大量的设备。设备驱动程序来与系统,包括大部分的数字转换器、打印机、绘图仪、视频显示板,和绘图仪市面上。

二维和三维制图支持起草线框模型。该系统设计作为一个画面CAD软件包。绘画元素线,poly-lines任何宽度、弧、圆形、脸、固体的方式很多,还定义一个绘画元素。例如,一个圆圈可以定义为中心及其半径、3分,和两个终点的直径。该系统总是提示用户所有选项。

当然,及时可以关掉了先进的用户。注释和标注也支持。符号文本和尺寸可以放在任何地方在图纸上,在任何角度看,而且在任何大小的。多种字体和风格也是可行的。

第九课

computer are used extensively in most engineering functions.计算机是最广泛使用的工程功能。

Engineering is a profession in which a knowledge of the natural sciences is applied with judgment to develop ways of using the materials and force of nature.工程是一种专业的自然科学知识应用判断发展的方式使用的材料和自然的力量。

Typical engineering functions using CAPACS (computer -aided production and control systems) are design, process planning, analysis and optimization, synthesis, evaluation and documentation, simulation, modeling, and quality control planning.典型工程使用功能capacs（计算机辅助生产和控制系统）设计，工艺规划，分析和优化，合成，评价和文件，仿真，建模，和质量控制计划。

Using CAPACS in engineering increases the productivity of engineers and improves the quality of design.使用capacs工程增加生产力和提高设计质量工程师。

For example, the application of computer to an engineering design process is performed by a CAD system.例如，计算机的应用到工程设计的过程是由一个计算机辅助设计系统。

Engineering can design and thoroughly test concept quickly and simply from one workstation.工程设计和彻底测试的概念迅速和简单地从一个工作站。

Computer permit engineers to take a concept from is original design through testing to numerical control (NC) output or a combination of steps in between.计算机允许工程师采取概念从原来的设计，通过测试数控（数控）输出或两者之间的步骤。

They perform complex scientific and engineering computations rapidly with high accuracy, calculate physical properties before actual are made and provide a fast, easy method to create model of even the most complex parts.他们进行复杂的科学和工程计算精度高，计算物理性能在实际制作提供了快速，简单的方法建立模型，即使是最复杂的部分。

The computer has influenced the way products are designed, documented and released for production.计算机已经影响到了产品设计的方式，记录和发布的生产。

AS technology develops, engineering operation becoming more and more automated are relieving the engineer of many tedious manual caculations.随着技术的发展，工程运行变得越来越自动化是使工程师减轻了很多繁琐的手工计算。

第十课

Numerical control may be defined as a method of accurately managing the movement of machine tools by a series of programmed numerical date which activate the, motors of the machine tool.数值控制可以被定义为一种精确控制机床运动的一系列程序数值日期激活，机床电机的。There is nothing complex or magical about this system.并不是很复杂的系统。It is based on the simple fundamental that combines automatic measurement of machine table slide will move with a series of programmed instructions.它是基于简单的基础，结合机床滑台的自动测量，将一系列的可编程指令。

The numerically controlled machine is supplied with detailed information regarding the part by means of punched tape.The machine decodes this punched information and electronic devices activate the various motors on the machine toll,causing them to position the work and follow specific machining instructions .The measuring and recording devices incorporated into numerically controlled machine tolls assure that the part being manufactured will be accurate.Numerically controlled machines minimize the possibility of human error which existed before their development. 在数控机床中有详细的信息关于提供部分通过穿孔带。这台机器代码信息和电子设备这穿孔激活各种电机在机床,使他们位置的工作,接受特殊的机加工指导书。测量和记录设备纳入数控机床确保部分损失正在制造的将是准确的。数控机床的可能性减少人类之前就已经存在误差的发展。Over recent years,the have been great improvements to NC systems.In many cases,the tape reader on NC machines is bypassed and the machine receives its instructions directly from a computer.However students should be made aware of the basics of NC before being exposed to the more recent developments of computerized numerical control (CNC) and direct numerical control(. 近年来,取得了巨大的改善数控系统。在很多情况下,对数控机床的纸带阅读机是绕过收到指令,直接从计算机。然而学生应该知道的基本数控之前被暴露在更近期的发展计算机数控(CNC)和直接数字控制（DNC)

第18章

压缩机是用于石油化工装置提高静压气体和空气的过程需要克服水平管道摩擦,效果一定反应点的最终交货,或传递所需的热力学性质与中等压缩。这些压缩机多种规格、类型、模型,其中每一个需要满足给定,可能代表最优配置为一组给定的要求。

压缩机类型必须的选择,因此,要在一个比较压缩机和服务要求的能力。

这首比较通常将回顾经济空间、安装成本、操作费用,以及维护要求竞争的类型。在一个压缩机的优势类型或模型提供了一个竞争不是很明显,一个更详细的分析可能是正当的。

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