英文(机器和机器零件的设计)Design of machine elements and machines
John Wiley 13 (2003) 137–149
https://www.wendangku.net/doc/4f16882207.html,
Mechanical design of machine elements and
machines:a failure prevention perspective
P. Paul Liu, Cisca Wijmenga, Amitav Hajra, Trevor B. Blake, Christine A. Kelley, Robert S. Adelstein, Adam Bagg, James Rector, James Cotelingam, Cheryl L.
Willman, Francis S. Collins
Genes, Chromosomes and Cancer
Volume 16, Issue 2, Date: June 1996, Pages: 137-149
Design of machine and machine elements
Machine design
Machine design is the art of planning or devising new or improved machines to accomplish specific purposes. In general, a machine will consist of a combination of several different mechanical elements properly designed and arranged to work together, as a whole. During the initial planning of a machine, fundamental decisions must be made concerning loading, type of kinematic elements to be used, and correct utilization of the properties of engineering materials. Economic considerations are usually of prime importance when the design of new machinery is undertaken. In general, the lowest over-all costs are designed. Consideration should be given not only to the cost of design, manufacture the necessary safety features and be of pleasing external appearance. The objective is to produce a machine which is not only sufficiently rugged to function properly for a reasonable life, but is at the same time cheap enough to be economically feasible.
The engineer in charge of the design of a machine should not only have adequate technical training, but must be a man of sound judgment and wide experience, qualities which are usually acquired only after considerable time has been spent in actual professional work.
Design of machine elements
The principles of design are, of course, universal. The same theory or equations may be applied to a very small part, as in an instrument, or, to a larger but similar part used in a piece of heavy equipment. In no ease, however, should mathematical calculations be looked upon as absolute and final. They are all subject to the accuracy of the various assumptions, which must necessarily be made in engineering work. Sometimes only a portion of the total number of parts in a machine are designed on the basis of analytic calculations. The form and size of the remaining parts are designed on the basis of analytic calculations. On the other hand, if the machine is very expensive, or if weight is a factor, as in airplanes, design computations may then be made for almost all the parts.
The purpose of the design calculations is, of course, to attempt to predict the stress or deformation in the part in order that it may sagely carry the loads, which will be imposed on it, and that it may last for the expected life of the machine. All calculations are, of course, dependent on the physical properties of the construction materials as determined by laboratory tests. A rational method of design attempts to take the results of relatively simple and fundamental tests such as tension, compression, torsion, and fatigue and apply them to all the complicated and involved situations encountered in present-day machinery.
In addition, it has been amply proved that such details as surface condition, fillets, notches, manufacturing tolerances, and heat treatment have a market effect on the strength and useful life of a machine part. The design and drafting departments must specify completely all such particulars, must specify completely all such particulars, and thus exercise the necessary close control over the finished product.
As mentioned above, machine design is a vast field of engineering technology. As such, it begins with the conception of an idea and follows through the various phases of design analysis, manufacturing, marketing and consumerism. The following is a list of
the major areas of consideration in the general field of machine design:
① Initial design conception;
② Strength analysis;
③ Materials selection;
④ Appearance;
⑤ Manufacturing;
⑥ Safety;
⑦ Environment effects;
⑨ Reliability and life;
Strength is a measure of the ability to resist, without fails, forces which cause stresses and strains. The forces may be;
① Gradually applied;
② Suddenly applied;
③ Applied under impact;
④ Applied with continuous direction reversals;
⑤ Applied at low or elevated temperatures.
If a critical part of a machine fails, the whole machine must be shut down until a repair is made. Thus, when designing a new machine, it is extremely important that critical parts be made strong enough to prevent failure. The designer should determine as precisely as possible the nature, magnitude, direction and point of application of all forces. Machine design is mot, however, an exact science and it is, therefore, rarely possible to determine exactly all the applied forces. In addition, different samples of a specified material will exhibit somewhat different abilities to resist loads, temperatures and other environment conditions. In spite of this, design calculations based on appropriate assumptions are invaluable in the proper design of machine.
Moreover, it is absolutely essential that a design engineer knows how and why parts fail so that reliable machines which require minimum maintenance can be designed. Sometimes, a failure can be serious, such as when a tire blows out on an automobile traveling at high speeds. On the other hand, a failure may be no more than a nuisance. An example is the loosening of the radiator hose in the automobile cooling system. The
consequence of this latter failure is usually the loss of some radiator coolant, a condition which is readily detected and corrected.
The type of load a part absorbs is just as significant as the magnitude. Generally speaking, dynamic loads with direction reversals cause greater difficulties than static loads and, therefore, fatigue strength must be considered. Another concern is whether the material is ductile or brittle. For example, brittle materials are considered to be unacceptable where fatigue is involved.
In general, the design engineer must consider all possible modes of failure, which include the following:
① Stress;
② Deformation;
③ Wear;
④ Corrosion;
⑤ Vibration;
⑥ Environmental damage;
⑦ Loosening of fastening devices.
The part sizes and shapes selected must also take into account many dimensional factors which produce external load effects such as geometric discontinuities, residual stresses due to forming of desired contours, and the application of interference fit joint. Selected from” design of machine elements”, 6th edition, m. f. sports, prentice-hall, inc., 1985 and “machine design”, Anthony Esposito, charles e., Merrill publishing company, 1975.
Mechanical properties of materials
The material properties can be classified into three major headings: (1) physical, (2) chemical, (3) mechanical
Physical properties
Density or specific gravity, moisture content, etc., can be classified under this category.
Chemical properties
Many chemical properties come under this category. These include acidity
or alkalinity, react6ivity and corrosion. The most important of these is corrosion which can be explained in layman’s terms as the resistance of the material to decay while in continuous use in a particular atmosphere.
Mechanical properties
Mechanical properties include in the strength properties like tensile, compression, shear, torsion, impact, fatigue and creep. The tensile strength of a material is obtained by dividing the maximum load, which the specimen bears by the area of cross-section of the specimen.
This is a curve plotted between the stress along the This is a curve plotted between the stress along the Y-axis(ordinate) and the strain along the X-axis (abscissa) in a tensile test. A material tends to change or changes its dimensions when it is loaded, depending upon the magnitude of the load. When the load is removed it can be seen that the deformation disappears. For many materials this occurs op to a certain value of the stress called the elastic limit Ap. This is depicted by the straight line relationship and a small deviation thereafter, in the stress-strain curve (fig.3.1)
. Within the elastic range, the limiting value of the stress up to which the stress and strain are proportional, is called the limit of proportionality Ap. In this region, the metal obeys hookes’s law, which states that the stress is proportional to strain in the elastic range of loading, (the material completely regains its original dimensions after the load is removed). In the actual plotting of the curve, the proportionality limit is obtained at a slightly lower value of the load than the
elastic limit. This may be attributed to the time-lagin the regaining of the original dimensions of the material. This effect is very frequently noticed in some non-ferrous metals.
Which iron and nickel exhibit clear ranges of elasticity, copper, zinc, tin, are found to be imperfectly elastic even at relatively low values low values of stresses. Actually the elastic limit is distinguishable from the proportionality limit more clearly depending upon the sensitivity of the measuring instrument.
When the load is increased beyond the elastic limit, plastic deformation starts. Simultaneously the specimen gets work-hardened. A point is reached when the deformation starts to occur more rapidly than the increasing load. This point is called they yield point Q. the metal which was resisting the load till then, starts to deform somewhat rapidly, i. e., yield. The yield stress is called yield limit Ay.
The elongation of the specimen continues from Q to S and then to T. The stress-strain relation in this plastic flow period is indicated by the portion QRST of the curve. At the specimen breaks, and this load is called the breaking load. The value of the maximum load S divided by the original cross-sectional area of the specimen is referred to as the ultimate tensile strength of the metal or simply the tensile strength Au.
Logically speaking, once the elastic limit is exceeded, the metal should start to yield, and finally break, without any increase in the value of stress. But the curve
records an increased stress even after the elastic limit is exceeded. Two reasons can be given for this behavior:
①The strain hardening of the material;
②The diminishing cross-sectional area of the specimen, suffered on account of the plastic deformation.
The more plastic deformation the metal undergoes, the harder it becomes, due to work-hardening. The more the metal gets elongated the more its diameter (and hence, cross-sectional area) is decreased. This continues until the point S is reached.
After S, the rate at which the reduction in area takes place, exceeds the rate at which the stress increases. Strain becomes so high that the reduction in area begins to produce a localized effect at some point. This is called necking.
Reduction in cross-sectional area takes place very rapidly; so rapidly that the load value actually drops. This is indicated by ST. failure occurs at this point T.
Then percentage elongation A and reduction in reduction in area W indicate the ductility or plasticity of the material:
A=(L-L0)/L0*100%
W=(A0-A)/A0*100%
Where L0 and L are the original and the final length of the specimen; A0 and A are the original and the final cross-section area.
Selected from “testing of metallic materials”
Quality assurance and control
Product quality is of paramount importance in manufacturing. If quality is allowed deteriorate, then a manufacturer will soon find sales dropping off followed by a possible business failure. Customers expect quality in the products they buy, and if a manufacturer expects to establish and maintain a name in the business, quality control and assurance functions must be established and maintained before, throughout, and after the production process. Generally speaking, quality assurance encompasses all activities aimed at maintaining quality, including quality control. Quality assurance can be divided into three major areas. These include the
following:
①Source and receiving inspection before manufacturing;
②In-process quality control during manufacturing;
③Quality assurance after manufacturing.
Quality control after manufacture includes warranties and product service extended to the users of the product.
Source and receiving inspection before manufacturing
Quality assurance often begins ling before any actual manufacturing takes place. This may be done through source inspections conducted at the plants that supply materials, discrete parts, or subassemblies to manufacturer. The manufacturer’s source inspector travels to the supplier factory and inspects raw material or premanufactured parts and assemblies. Source inspections present an opportunity
for the manufacturer to sort out and reject raw materials or parts before they are shipped to the manufacturer’s production facility.
The responsibility of the source inspector is to check materials and parts against design specifications and to reject the item if specifications are not met. Source inspections may include many of the same inspections that will be used during production. Included in these are:
①Visual inspection;
②Metallurgical testing;
③Dimensional inspection;
④Destructive and nondestructive inspection;
⑤Performance inspection.
Visual inspections
Visual inspections examine a product or material for such specifications as color, texture, surface finish, or overall appearance of an assembly to determine if there are any obvious deletions of major parts or hardware.
Metallurgical testing
Metallurgical testing is often an important part of source inspection, especially if
the primary raw material for manufacturing is stock metal such as bar stock or
structural materials. Metals testing can involve all the major types of inspections including visual, chemical, spectrographic, and mechanical, which include hardness, tensile, shear, compression, and spectr5ographic analysis for alloy content. Metallurgical testing can be either destructive or nondestructive.
Dimensional inspection
Few areas of quality control are as important in manufactured products as dimensional requirements. Dimensions are as important in source inspection as they are in the manufacturing process. This is especially critical if the source supplies parts for an assembly. Dimensions are inspected at the source factory using standard measuring tools plus special fit, form, and function gages that may required. Meeting dimensional specifications is critical to interchangeability of manufactured parts and to the successful assembly of many parts into complex assemblies such as autos, ships, aircraft, and other multipart products.
Destructive and nondestructive inspection
In some cases it may be necessary for the source inspections to call for destructive or nondestructive tests on raw materials or p0arts and assemblies. This is particularly true when large amounts of stock raw materials are involved. For example it may be necessary to inspect castings for flaws by radiographic, magnetic particle, or dye penetrant techniques before they are shipped to the manufacturer for final machining. Specifications calling for burn-in time for electronics or endurance run tests for mechanical components are further examples of nondestructive tests.
It is sometimes necessary to test material and parts to destruction, but because of the costs and time involved destructive testing is avoided whenever possible. Examples include pressure tests to determine if safety factors are adequate in the design. Destructive tests are probably more frequent in the testing of prototype designs than in routine inspection of raw material or parts. Once design specifications are known to be met in regard to the strength of materials, it is often not necessary to test further parts to destruction unless they are genuinely suspect. Performance inspection
Performance inspections involve checking the function of assemblies, especially those of complex mechanical systems, prior to installation in other products. Examples include electronic equipment subcomponents, aircraft and auto engines, pumps, valves, and other mechanical systems requiring performance evaluation prior to their shipment and final installation.
Selected form “modern materials and manufacturing process”
Electro-hydraulic drum brakes
Application
The YWW series electro-hydraulic brake is a normally closed brake, suitable for horizontal mounting. It is mainly used in portal cranes, bucket stacker/
reclaimers’slewing mechanism.
The YKW series electro-hydraulic brake is a normally opened brake, suitable for horizontal mounting, employing a thruster as actuator. with the foot controlling switch the operator can release or close the brake. It is mainly used for deceleration braking of portal cranes’slewing mechanism. In a non-operating state the machinery can be braked by a manual close device.
The RKW series brake is a normally opened brake, which is operated by foot driven hydraulic pump, suitable for horizontal mounting. Mainly used in the slewing mechanism of middle and small portal cranes. When needed, the brake is activated by a manual closed device.
Main design features
Interlocking shoes balancing devices (patented technology) constantly equalizes the clearance of brake shoes on both sides and made adjustment unnecessary, thus avoiding one side of the brake lining sticking to the brake wheel. The brake is equipped with a shoed autoaligning device.
Main hinge points are equipped with self-lubricating bearing, making high efficiency of transmission, long service life. Lubricating is unnecessary during operation.
Adjustable bracket ensure the brake works well.
The brake spring is arranged inside a square tube and a surveyor’s rod is placed
on one side. It is easy to read braking torque value and avoid measuring and computing.
Brake lining is of card whole-piece shaping structure, easy to replace. Brake linings of various materials such as half-metal (non-asbestos) hard and half-hard, soft (including asbestos) substance are available for customers to choose.
All adopt the company’s new types of thruster as corollary equipment which work accurately and have long life.
Hydraulic Power Transmission
The Two Types Of Power Transmission
In hydraulic power transmission the apparatus (pump) used for conversion of the mechanical (or electrical,thermal) energy to hydraulic energy is arranged on the input of the kinematic chain ,and the apparatus (motor) used for conversion of the hydraulic energy to mechanical energy is arranged on the output (fig.2-1)
The theoretical design of the energy converters depends on the component of the bernouilli equation to be used for hydraulic power transmission.
In systerms where, mainly, hydrostatic pressure is utilized, displacement (hydrostatic) pumps and motors are used, while in those where the hydrodynamic pressure is utilized is utilized gor power transmission hydrodynamic energy converters (e.g. centrifugal pumps) are used.
The specific characteristic of the energy converters is the weight required for transmission of unit power. It can be demonstrated that the use of hydrostatic energy converters for the low and medium powers, and of hydrodynamic energy converters of high power are more favorite (fig.2-2). This is the main reason why hydrostatic energy converters are used in industrial apparatus. transformation of the energy in hydraulic transmission.
1. driving motor (electric, diesel engine);
energy;
2. mechanical
3. pump;
4. hydraulic energy;
motor;
5. hydraulic
energy;
6. mechanical
7. load variation of the mass per unit power in hydrostatic and hydrodynamic energy
converters
1、hydrostatic; 2.hydrodynamic
Only displacement energy converters are dealt with in the following. The elements performing converters provide one or several size. Expansion of the working chambers in a pump is produced by the external energy admitted, and in the motor by the hydraulic energy. Inflow of the fluid occurs during expansion of the working chamber, while the outflow (displacement) is realized during contraction. Such devices are usually called displacement energy converters.
The Hydrostatic Power
In order to have a fluid of volume V1 flowing in a vessel at pressure work spent on compression W1 and transfer of the process, let us imagine a piston mechanism (fig.2-3(a)) which may be connected with the aid of valves Z0 and Z1 to the external medium under pressure P0 and reservoir of pressure p1.in the upper position of the piston (x=x0) with Z0 open the cylinder chamber is filled with fluid of volume V0 and pressure P0. now shut the value Z0 and start the piston moving downwards. If Z1 is shut the fluid volume in position X=X1 of the piston decreases from V0 to V1, while the pressure rises to P1. the external work required for actuation of the piston (assuming isothermal change) is
W1=-∫0x0(P-P0)Adx=-∫v1v0(P-P0)dv
Select from Hydraulic Power Transmission
冲压模具技术外文翻译(含外文文献)
前言 在目前激烈的市场竞争中，产品投入市场的迟早往往是成败的关键。模具是高质量、高效率的产品生产工具，模具开发周期占整个产品开发周期的主要部分。因此客户对模具开发周期要求越来越短，不少客户把模具的交货期放在第一位置，然后才是质量和价格。因此，如何在保证质量、控制成本的前提下加工模具是值得认真考虑的问题。模具加工工艺是一项先进的制造工艺，已成为重要发展方向，在航空航天、汽车、机械等各行业得到越来越广泛的应用。模具加工技术，可以提高制造业的综合效益和竞争力。研究和建立模具工艺数据库，为生产企业提供迫切需要的高速切削加工数据，对推广高速切削加工技术具有非常重要的意义。本文的主要目标就是构建一个冲压模具工艺过程，将模具制造企业在实际生产中结合刀具、工件、机床与企业自身的实际情况积累得高速切削加工实例、工艺参数和经验等数据有选择地存储到高速切削数据库中，不但可以节省大量的人力、物力、财力，而且可以指导高速加工生产实践，达到提高加工效率，降低刀具费用，获得更高的经济效益。 1.冲压的概念、特点及应用 冲压是利用安装在冲压设备（主要是压力机）上的模具对材料施加压力，使其产生分离或塑性变形，从而获得所需零件（俗称冲压或冲压件）的一种压力加工方法。冲压通常是在常温下对材料进行冷变形加工，且主要采用板料来加工成所需零件，所以也叫冷冲压或板料冲压。冲压是材料压力加工或塑性加工的主要方法之一，隶属于材料成型工程术。 冲压所使用的模具称为冲压模具，简称冲模。冲模是将材料（金属或非金属）批量加工成所需冲件的专用工具。冲模在冲压中至关重要，没有符合要求的冲模，批量冲压生产就难以进行；没有先进的冲模，先进的冲压工艺就无法实现。冲压工艺与模具、冲压设备和冲压材料构成冲压加工的三要素，只有它们相互结合才能得出冲压件。 与机械加工及塑性加工的其它方法相比，冲压加工无论在技术方面还是经济方面都具有许多独特的优点，主要表现如下； (1) 冲压加工的生产效率高，且操作方便，易于实现机械化与自动化。这是
机械手机械设计中英文对照外文翻译文献
(文档含英文原文和中文翻译) 中英文对照翻译 机械设计 摘要： 机器由机械和其他元件组成的用来转换和传输能量的装置。比如：发动机、涡轮机、车、起重机、印刷机、洗衣机和摄影机。许多机械方面设计的原则和方法也同样适用于非机械方面。术语中的“构造设计”的含义比“机
械设计”更加广泛，构造设计包括机械设计。在进行运动分析和结构设计时要把产品的维护和外形也考虑在机械设计中。在机械工程领域中，以及其它工程领域，都需要机械设备，比如：开关、凸轮、阀门、船舶以及搅拌机等。关键词：设计流程设计规则机械设计 设计流程 设计开始之前就要想到机器的实用性，现有的机器需要在耐用性、效率、重量、速度，或者成本上得到改善。新的机器必需能够完全或部分代替以前人的功能，比如计算、装配、维修。 在设计的初级阶段，应该充分发挥设计人员的创意，不要受到任何约束。即使有一些不切实际的想法，也可以在设计的早期，即在绘制图纸之前被改正掉。只有这样，才不致于阻断创新的思路。通常,必须提出几套设计方案,然后进行比较。很有可能在这个计划最后指定使用某些不在计划方案内的一些想法的计划。 一般当产品的外型和组件的尺寸特点已经显现出来的时候，就可以进行全面的设计和分析。接着还要客观的分析机器性能、安全、重量、耐用性，并且成本也要考虑在内。每一个至关重要的部分要优化它的比例和尺寸，同时也要保持与其它组成部分的平衡。 选择原材料和工艺的方法。通过力学原理来分析和实现这些重要的特性，如稳定和反应的能量和摩擦力的利用，动力惯性、加速度、能量；包括材料的弹性强度、应力和刚度等物理特性，以及流体的润滑和驱动器的流体力学。设计的过程是一个反复与合作的过程，无论是正式的还是非正式的，对设计者来说每个阶段都很重要。。产品设计需要大量的研究和提升。许多的想法,必须通过努力去研究成为一种理念,然后去使用或放弃。虽然每个工
机械毕业设计英文外文翻译460数字控制 (2)
附录 科技译文： Numerical Control Numerical Control(NC) is a method of controlling the movements of machineComponents by directly inserting coded instructions in the form of numerical data(numbers and data ) into the system.The system automatically interprets these data and converts to output signals. These signals ,in turn control various machine components ,such as turning spindles on and off ,changing tools,moving the work piece or the tools along specific paths,and turning cutting fluits on and off. In order to appreciate the importer of numerical control of machines ,let’s briefly review how a process such as machining has been carried out traditionally .After studying the working drawing of a part, the operator sets up the appropriate process parameters(such as cutting speed ,feed,depth of cut,cutting fluid ,and so on),determines the sequence of operations to be performed,clamps the work piece in a workholding device such as chuck or collet ,and proceeds to make the part .Depending on part shape and the dimensional accuracy specified ,this approach usually requires skilled
翻译基本理论知识
翻译概述（1） 一、学科特点 翻译是一种跨越时空的语言活动，是"把一种语言已经表达出来的东西用另一种语言准确而完整地重新表达出来"(范存忠："漫谈翻译"《翻译理论与技巧》中国对外翻译出版公司，1985，p.80), 是"从语义到文体在译入语中用最切近而又最自然的对等语再现原语的信息"（谭载喜：《奈达论翻译》中国对外翻译出版公司，1984，p.10）。翻译虽为个体所承作，却是一种社会活动，一门综合性很强的学科。它既有很强的理论性又有丰富的实践内涵。就前者而言，翻译经过千百年来各国翻译家的共同努力，已经在语言学、文学、文化、心理学、人类学、哲学和教育学等学科的基础上初步建立了一套理论体系，并在具体实践中总结出了一套行之有效的跨文化和语言转换模式。随着科学的日益进步，这种体系和模式正处在不断地完善之中。就后者而言，翻译是人类社会活动的产物，具有很强的实践性。翻译理论与实践的关系是辨证的；翻译理论产生于翻译实践，反过来又指导实践，实践转过来又丰富翻译理论。可以说，没有社会实践就不会有翻译理论的产生；没有翻译理论作为指导，翻译实践就会难免走弯路。因此，学好翻译既要重视翻译理论的学习，又要加强翻译实践；理论联系实际，这是我们学好翻译的必由之路。 二、为什么可能有翻译 翻译是人类社会发展和进步的需要，因为人类社会要发展进步就需要在不同文化的民族之间进行沟通，而这一全过程都离不开翻译。正如Steiner和张培基所说的那样：Translating it is that openeth the window, to let in the light; that breaketh the shell, that we may eat the kernel. (Steiner) 翻译是沟通各族人民的思想，促进政治、经济、文化、科学、技术交流的重要手段，
机械设计外文翻译(中英文)
机械设计理论 机械设计是一门通过设计新产品或者改进老产品来满足人类需求的应用技术科学。它涉及工程技术的各个领域，主要研究产品的尺寸、形状和详细结构的基本构思，还要研究产品在制造、销售和使用等方面的问题。 进行各种机械设计工作的人员通常被称为设计人员或者机械设计工程师。机械设计是一项创造性的工作。设计工程师不仅在工作上要有创造性，还必须在机械制图、运动学、工程材料、材料力学和机械制造工艺学等方面具有深厚的基础知识。如前所诉，机械设计的目的是生产能够满足人类需求的产品。发明、发现和科技知识本身并不一定能给人类带来好处，只有当它们被应用在产品上才能产生效益。因而，应该认识到在一个特定的产品进行设计之前，必须先确定人们是否需要这种产品。 应当把机械设计看成是机械设计人员运用创造性的才能进行产品设计、系统分析和制定产品的制造工艺学的一个良机。掌握工程基础知识要比熟记一些数据和公式更为重要。仅仅使用数据和公式是不足以在一个好的设计中做出所需的全部决定的。另一方面，应该认真精确的进行所有运算。例如，即使将一个小数点的位置放错，也会使正确的设计变成错误的。 一个好的设计人员应该勇于提出新的想法，而且愿意承担一定的风险，当新的方法不适用时，就使用原来的方法。因此，设计人员必须要有耐心，因为所花费的时间和努力并不能保证带来成功。一个全新的设计，要求屏弃许多陈旧的，为人们所熟知的方法。由于许多人墨守成规，这样做并不是一件容易的事。一位机械设计师应该不断地探索改进现有的产品的方法，在此过程中应该认真选择原有的、经过验证的设计原理，将其与未经过验证的新观念结合起来。 新设计本身会有许多缺陷和未能预料的问题发生，只有当这些缺陷和问题被解决之后，才能体现出新产品的优越性。因此，一个性能优越的产品诞生的同时，也伴随着较高的风险。应该强调的是，如果设计本身不要求采用全新的方法，就没有必要仅仅为了变革的目的而采用新方法。 在设计的初始阶段，应该允许设计人员充分发挥创造性，不受各种约束。即使产生了许多不切实际的想法，也会在设计的早期，即绘制图纸之前被改正掉。只有这样，才不致于堵塞创新的思路。通常，要提出几套设计方案，然后加以比较。很有可能在最后选定的方案中，采用了某些未被接受的方案中的一些想法。
机械手外文翻译 修改版
密级 分类号 编号 成绩 本科生毕业设计 (论文) 外文翻译 原文标题Simple Manipulator And The Control Of It 译文标题简易机械手及控制 作者所在系别机械工程系 作者所在专业xxxxx 作者所在班级xxxxxxxx 作者姓名xxxx 作者学号xxxxxx 指导教师姓名xxxxxx 指导教师职称副教授 完成时间2012 年02 月 北华航天工业学院教务处制
译文标题简易机械手及控制 原文标题 Simple Manipulator And The Control Of It 作者机电之家译名JDZJ国籍中国 原文出处机电之家 中文译文： 简易机械手及控制 随着社会生产不断进步和人们生活节奏不断加快,人们对生产效率也不断提出新要求。由于微电子技术和计算软、硬件技术的迅猛发展和现代控制理论的不断完善,使机械手技术快速发展,其中气动机械手系统由于其介质来源简便以及不污染环境、组件价格低廉、维修方便和系统安全可靠等特点,已渗透到工业领域的各个部门,在工业发展中占有重要地位。本文讲述的气动机械手有气控机械手、XY轴丝杠组、转盘机构、旋转基座等机械部分组成。主要作用是完成机械部件的搬运工作,能放置在各种不同的生产线或物流流水线中,使零件搬运、货物运输更快捷、便利。 一.四轴联动简易机械手的结构及动作过程 机械手结构如下图1所示,有气控机械手(1)、XY轴丝杠组(2)、转盘机构(3)、旋转基座(4)等组成。 图1.机械手结构 其运动控制方式为：(1)由伺服电机驱动可旋转角度为360°的气控机械手(有光电传感器确定起始0点);(2)由步进电机驱动丝杠组件使机械手沿X、Y轴移动(有x、y轴限位开关);(3)可回旋360°的转盘机构能带动机械手及丝杠组自由旋转(其电气拖动部分由直流电动机、光电编码器、接近开关等组成);(4)旋转基座主要支撑以上3部分;(5)气控机械手的张合由气压控制(充气时机械手抓紧,放气时机械手松开)。 其工作过程为：当货物到达时,机械手系统开始动作;步进电机控制开始向下
机械毕业设计英文外文翻译204机电一体化
附录 INTEGRATION OF MACHINERY （From ELECTRICAL AND MACHINERY INDUSTRY）ABSTRACT Machinery was the modern science and technology development inevitable result, this article has summarized the integration of machinery technology basic outline and the development background .Summarized the domestic and foreign integration of machinery technology present situation, has analyzed the integration of machinery technology trend of development. Key word：integration of machinery ，technology，present situation ，product t，echnique of manufacture ，trend of development 0. Introduction modern science and technology unceasing development, impelled different discipline intersecting enormously with the seepage, has caused the project domain technological revolution and the transformation .In mechanical engineering domain, because the microelectronic technology and the computer technology rapid development and forms to the mechanical industry seepage the integration of machinery, caused the mechanical industry the technical structure, the product organization, the function and the constitution, the production method and the management system has had the huge change, caused the industrial production to enter into “the integration of machinery” by “the machinery electrification” for the characteristic development phase. 1. Integration of machinery outline integration of machinery is refers in the organization new owner function, the power function, in the information processing function and the control function introduces the electronic technology, unifies the system the mechanism and the computerization design and the software which constitutes always to call. The integration of machinery development also has become one to have until now own system new discipline, not only develops along with the science and technology, but also entrusts with the new content .But its basic characteristic may summarize is: The integration of machinery is embarks from the system viewpoint, synthesis community technologies and so on utilization mechanical technology, microelectronic technology, automatic control technology,
机械类外文翻译
机械类外文翻译 塑料注塑模具浇口优化 摘要:用单注塑模具浇口位置的优化方法，本文论述。该闸门优化设计的目的是最大限度地减少注塑件翘曲变形，翘曲，是因为对大多数注塑成型质量问题的关键，而这是受了很大的部分浇口位置。特征翘曲定义为最大位移的功能表面到表面的特征描述零件翘曲预测长度比。结合的优化与数值模拟技术，以找出最佳浇口位置，其中模拟armealing算法用于搜索最优。最后，通过实例讨论的文件，它可以得出结论，该方法是有效的。 注塑模具、浇口位臵、优化、特征翘曲变形关键词: 简介 塑料注射成型是一种广泛使用的，但非常复杂的生产的塑料产品，尤其是具有高生产的要求，严密性，以及大量的各种复杂形状的有效方法。质量ofinjection 成型零件是塑料材料，零件几何形状，模具结构和工艺条件的函数。注塑模具的一个最重要的部分主要是以下三个组件集:蛀牙，盖茨和亚军，和冷却系统。拉米夫定、Seow(2000)、金和拉米夫定(2002) 通过改变部分的尼斯达到平衡的腔壁厚度。在平衡型腔充填过程提供了一种均匀分布压力和透射电镜,可以极大地减少高温的翘曲变形的部分～但仅仅是腔平衡的一个重要影响因素的一部分。cially Espe,部分有其功能上的要求,其厚度通常不应该变化。 pointview注塑模具设计的重点是一门的大小和位臵,以及流道系统的大小和布局。大门的大小和转轮布局通常被认定为常量。相对而言,浇口位臵与水口大小布局也更加灵活,可以根据不同的零件的质量。 李和吉姆(姚开屏,1996a)称利用优化流道和尺寸来平衡多流道系统为multiple 注射系统。转轮平衡被形容为入口压力的差异为一多型腔模具用相同的蛀牙,也存
机械手设计英文参考文献原文翻译
机械手设计英文参考文 献原文翻译 Company number：【WTUT-WT88Y-W8BBGB-BWYTT-19998】
翻译人：王墨墨山东科技大学 文献题目：Automated Calibration of Robot Coordinates for Reconfigurable Assembly Systems 翻译正文如下： 针对可重构装配系统的机器人协调性的自动校准 T.艾利，Y.米达，H.菊地，M.雪松 日本东京大学，机械研究院，精密工程部 摘要 为了实现流水工作线更高的可重构性，以必要设备如机器人的快速插入插出为研究目的。当一种新的设备被装配到流水工作线时，应使其具备校准系统。该研究使用两台电荷耦合摄像机，基于直接线性变换法，致力于研究一种相对位置/相对方位的自动化校准系统。摄像机被随机放置，然后对每一个机械手执行一组动作。通过摄像机检测机械手动作，就能捕捉到两台机器人的相对位置。最佳的结果精度为均方根值毫米。 关键词： 装配，校准，机器人 1 介绍 21世纪新的制造系统需要具备新的生产能力，如可重用性，可拓展性，敏捷性以及可重构性 [1]。系统配置的低成本转变，能够使系统应对可预见的以及不可预见的市场波动。关于组装系统，许多研究者提出了分散的方法来实现可重构性[2][3]。他们中的大多数都是基于主体的系统，主体逐一协同以建立一种新的
配置。然而，协同只是目的的一部分。在现实生产系统中，例如工作空间这类物理问题应当被有效解决。 为了实现更高的可重构性，一些研究人员不顾昂贵的造价，开发出了特殊的均匀单元[4][5][6]。作者为装配单元提出了一种自律分散型机器人系统，包含多样化的传统设备[7][8]。该系统可以从一个系统添加/删除装配设备，亦或是添加/删除装配设备到另一个系统；它通过协同作用，合理地解决了工作空间的冲突问题。我们可以把该功能称为“插入与生产”。 表1：合作所需的调节和量度 在重构过程中，校准的装配机器人是非常重要的。这是因为，需要用它们来测量相关主体的特征，以便在物理主体之间建立良好的协作关系。这一调整必须要达到表1中所列到的多种标准要求。受力单元和方向的调整是不可避免的，以便使良好的协同控制得以实现。从几何标准上看，位置校准是最基本的部分。一般来说，校准被理解为“绝对”，即，关于特定的领域框架；或者“相对”，即，关于另一个机器人的基本框架。后者被称为“机器人之间的校准”。 个体机器人的校准已被广泛研究过了。例如，运动参数的识别就非常受欢迎。然而，很少有对机器人之间校准的研究。玉木等人是用一种基于标记的方法，在一个可重构的装配单元内，校准机器人桌子和移动机械手之间的相互位置/方向联系。波尼兹和夏发表了一种校准方法。该方法通过两个机械手的机械接触来实现，实验非常耗时，并要求特别小心地操作。
机械类毕业设计外文翻译
本科毕业论文(设计) 外文翻译 学院：机电工程学院 专业：机械工程及自动化 姓名：高峰 指导教师：李延胜 2011年05 月10日 教育部办公厅 Failure Analysis，Dimensional Determination And
Analysis，Applications Of Cams INTRODUCTION It is absolutely essential that a design engineer know how and why parts fail so that reliable machines that require minimum maintenance can be designed．Sometimes a failure can be serious，such as when a tire blows out on an automobile traveling at high speed．On the other hand，a failure may be no more than a nuisance．An example is the loosening of the radiator hose in an automobile cooling system．The consequence of this latter failure is usually the loss of some radiator coolant，a condition that is readily detected and corrected．The type of load a part absorbs is just as significant as the magnitude．Generally speaking，dynamic loads with direction reversals cause greater difficulty than static loads，and therefore，fatigue strength must be considered．Another concern is whether the material is ductile or brittle．For example，brittle materials are considered to be unacceptable where fatigue is involved． Many people mistakingly interpret the word failure to mean the actual breakage of a part．However，a design engineer must consider a broader understanding of what appreciable deformation occurs．A ductile material，however will deform a large amount prior to rupture．Excessive deformation，without fracture，may cause a machine to fail because the deformed part interferes with a moving second part．Therefore，a part fails(even if it has not physically broken)whenever it no longer fulfills its required function．Sometimes failure may be due to abnormal friction or vibration between two mating parts．Failure also may be due to a phenomenon called creep，which is the plastic flow of a material under load at elevated temperatures．In addition，the actual shape of a part may be responsible for failure．For example，stress concentrations due to sudden changes in contour must be taken into account．Evaluation of stress considerations is especially important when there are dynamic loads with direction reversals and the material is not very ductile． In general，the design engineer must consider all possible modes of failure，which include the following． ——Stress ——Deformation ——Wear ——Corrosion ——Vibration ——Environmental damage ——Loosening of fastening devices
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近几年，我厂和英国、西班牙的几个公司有业务往来，外商传真发来的图纸都是英文标注，平时阅看有一定的困难。下面把我们积累的几点看英文图纸的经验与同行们交流。 1标题栏 英文工程图纸的右下边是标题栏（相当于我们的标题栏和部分技术要求），其中有图纸名称（TILE）、设计者（DRAWN）、审查者（CHECKED）、材料（MATERIAL）、日期（DATE）、比例（SCALE）、热处理（HEAT TREATMENT）和其它一些要求，如： 1)TOLERANCES UNLESS OTHERWISE SPECIFIAL 未注公差。 2)DIMS IN mm UNLESS STATED 如不做特殊要求以毫米为单位。 3)ANGULAR TOLERANCE±1°角度公差±1°。 4)DIMS TOLERANCE±0.1未注尺寸公差±0.1。 5)SURFACE FINISH 3.2 UNLESS STATED未注粗糙度3.2。 2常见尺寸的标注及要求 2.1孔（HOLE）如： （1）毛坯孔：3"DIAO+1CORE 芯子3"0+1; （2）加工孔：1"DIA1"; （3）锪孔：锪孔(注C＇BORE=COUNTER BORE锪底面孔); （4）铰孔：1"/4 DIA REAM铰孔1"/4; （5）螺纹孔的标注一般要表示出螺纹的直径，每英寸牙数（螺矩）、螺纹种类、精度等级、钻深、攻深，方向等。如： 例1.6 HOLES EQUI-SPACED ON 5"DIA (6孔均布在5圆周上（EQUI-SPACED=EQUALLY SPACED均布） DRILL 1"DIATHRO＇ 钻1"通孔（THRO＇=THROUGH通） C/SINK22×6DEEP 沉孔22×6 例2.TAP7"/8-14UNF-3BTHRO＇ 攻统一标准细牙螺纹，每英寸14牙，精度等级3B级 （注UNF=UNIFIED FINE THREAD美国标准细牙螺纹） 1"DRILL 1"/4-20 UNC-3 THD7"/8 DEEP 4HOLES NOT BREAK THRO钻 1"孔，攻1"/4美国粗牙螺纹，每英寸20牙，攻深7"/8,4孔不准钻通（UNC=UCIFIED COARSE THREAD 美国标准粗牙螺纹）
机械手文献综述
毕业设计（论文） 文献综述 设计（论文）题目：4自由度气动机械手设计 学院名称：机械工程学院 专业：机械设计制造及其自动化 学生姓名：卢锋学号：07403010309 指导教师：杨超珍 2010年12 月24 日
机械手的发展及应用 前言 机械工业是国民的装备部，是为国民经济提供装备和为人民生提供耐用消费品的产业。机械工业的规模和技术水平是衡量国家经济实力和科学技术水平的要标志。因此，世界各国都把发展机械工业作为发展本国经济的战略重点之一。生产水平及科学技术的不断进步与发展带动了整个机械工业的快速发展。现代工业中，生产过程的机械化，自动化已成为突出的主题。然而在机械工业中，加工、装配等生产是不连续的。单靠人力将这些不连续的生产工序接起来，不仅费时而且效率不高。同时人的劳动强度非常大，有时还会出现失误及伤害。显然，这严重影响制约了整个生产过程的效率和自动化程度。机械手的应用很好的解决了这一情况，它不存在重复的偶然失误，也能有效的避免了人身事故。 1.机械手的组成 1.1 执行机构 机械手主要由执行机构、驱动机构和控制系统三大部分组成。其组成及相互关系如下图： （1）手部 手部安装在手臂的前端。手臂的内孔装有转动轴，可把动作传给手腕，以转动、伸屈手腕，开闭手指。 机械手手部的机构系模仿人的手指，分为无关节，固定关节和自由关节三种。手指的数量又可以分为二指、三指和四指等，其中以二指用的最多。可以根据夹持对象的形状和大小配备多种形状和尺寸的夹头，以适应操作需要。
（2）手臂 手臂有无关节和有关节手臂之分本课所做的机械手的手臂采用无关节臂手臂的作用是引导手指准确的抓住工件，并运送到所需要的位置上。为了使机械手能够正确的工作，手臂的三个自由度都需要精确的定位。 总括机械手的运动离不开直线移动和转动二种，因此，它采用的执行机构主要是直线油缸、摆动油缸、电液脉冲马达、伺服油马达、直流伺服马达和步进马达等。 躯干是安装手臂、动力源和执行机构的支架。 1.2 驱动机构 驱动机构主要有四种：液压驱动、气压驱动、电气驱动和机械驱动。其中以液压气动用的最多，占90%以上，电动、机械驱动用的较少。 液压驱动主要是通过油缸、阀、油泵和油箱等实现传动。它利用油缸、马达加上齿轮、齿条实现直线运动；利用摆动油缸、马达与减速器、油缸与齿条、齿轮或链条、链轮等实现回转运动。液压驱动的优点是压力高、体积小、出力大、运动平缓，可无级变速，自锁方便，并能在中间位置停止。缺点是需要配备压力源，系统复杂成本较高。 气压驱动所采用的元件为气压缸、气压马达、气阀等。一般采用4-6 个大气压，个别的达到 8-10 个大气压。它的优点是气源方便，维护简单，成本低。缺点是出力小，体积大。由于空气的可压缩性大，很难实现中间位置的停止，只能用于点位控制，而且润滑性较差，气压系统容易生锈。 电气驱动采用的不多。现在都用三相感应电动机作为动力，用大减速比减速器来驱动执行机构；直线运动则用电动机带动丝杠螺母机构；有的采用直线电动机。通用机械手则考虑用步进电机、直流或交流的伺服电机、变速箱等。电气驱动的优点是动力源简单，维护，使用方便。驱动机构和控制系统可以采用统一形式的动力，出力比较大；缺点是控制响应速度比较慢。机械驱动只用于固定的场合。一般用凸轮连杆机构实现规定的动作。它的优点是动作确实可靠，速度高，成本低；缺点是不易调整。 1.3 控制系统 机械手控制系统的要素，包括工作顺序、到达位置、动作时间和加速度等。 控制系统可根据动作的要求，设计采用数字顺序控制。它首先要编制程序加以存储，然后再根据规定的程序，控制机械手进行工作。随着科学技术的发展，机械手也越来越多的地被应用。
机械类毕业设计外文文献翻译
沈阳工业大学工程学院 毕业设计（论文）外文翻译 毕业设计（论文）题目：工具盒盖注塑模具设计 外文题目：Friction , Lubrication of Bearing 译文题目：轴承的摩擦与润滑 系（部）：机械系 专业班级：机械设计制造及其自动化0801 学生姓名：王宝帅 指导教师：魏晓波 2010年10 月15 日
外文文献原文： Friction , Lubrication of Bearing In many of the problem thus far , the student has been asked to disregard or neglect friction . Actually , friction is present to some degree whenever two parts are in contact and move on each other. The term friction refers to the resistance of two or more parts to movement. Friction is harmful or valuable depending upon where it occurs. friction is necessary for fastening devices such as screws and rivets which depend upon friction to hold the fastener and the parts together. Belt drivers, brakes, and tires are additional applications where friction is necessary. The friction of moving parts in a machine is harmful because it reduces the mechanical advantage of the device. The heat produced by friction is lost energy because no work takes place. Also , greater power is required to overcome the increased friction. Heat is destructive in that it causes expansion. Expansion may cause a bearing or sliding surface to fit tighter. If a great enough pressure builds up because made from low temperature materials may melt. There are three types of friction which must be overcome in moving parts: (1)starting, (2)sliding, and(3)rolling. Starting friction is the friction between two solids that tend to resist movement. When two parts are at a state of rest, the surface irregularities of both parts tend to interlock and form a wedging action. To produce motion in these parts, the wedge-shaped peaks and valleys of the stationary surfaces must be made to slide out and over each other. The rougher the two surfaces, the greater is starting friction resulting from their movement . Since there is usually no fixed pattern between the peaks and valleys of two mating parts, the irregularities do not interlock once the parts are in motion but slide over each other. The friction of the two surfaces is known as sliding friction. As shown in figure ,starting friction is always greater than sliding friction . Rolling friction occurs when roller devces are subjected to tremendous stress which cause the parts to change shape or deform. Under these conditions, the material in front of a roller tends to pile up and forces the object to roll slightly uphill. This changing of shape , known as deformation, causes a movement of molecules. As a result ,heat is produced from the added energy required to keep the parts turning and overcome friction. The friction caused by the wedging action of surface irregularities can be overcome
翻译基本概念
《翻译》课程理论汇编（基本概念） 1.1 翻译的概念 一般地，我们将翻译定义为：将一种语言（口语或笔语形式）（译出语）转换或创造为另一种语言（译入语）。翻译是一种非常复杂的 人类高级语言活动，这种活动的整个过程是很难以图示、语言等其他方式阐释清楚的。不同领域、不同派别的学者对翻译有着不同的定义。 1.1.1 语言学家对翻译的定义 语言学家将翻译视为一种语言活动，同时认为，翻译理论属于语言学的一个部分，即研究译出语和译入语的转换关系。解释如下： （1）Catford（1965：20）认为，翻译是译出语和译入语间的文本等效转换。 （2）Nida 和Taber（1969：12）认为，翻译是译出语和译入语间意义和形式上的最紧密联系转换。 （3）Newmark（1982/1988：5）认为，翻译理论源自于比较语言学，属于语义学的一部分，而所有语义学的研究课题都与翻译理论息 息相关。 1.1.2 文化角度对翻译的定义 从文化角度来看，翻译不仅仅是语言符号的转换，同时是文化的交流，尤其是“文化间交流”。通常我们把这一术语又改称为“文化 间合作”或“跨文化交际”等。 Shuttleworth 和Cowie（1997：35）认为，与其说翻译是两种语言之间的符号转换，不如说是两种语言所代表的两种文化间的转换。 译者在处理涉及语言文化方面的译务工作时，认为任何一种语言中都饱含着其文化中的相关元素（比如：语言中的问候语、固定搭配 等），任何文本都存在于特定的文化环境中，同时，由于各语言所代表的多元文化差异很大，语言间的转化和创造性生成模式千变万化。 Nida 认为，对于一个成功的翻译工作者而言，掌握两种文化比掌握两种语言更为重要，因为语言中的词汇只有在特定的语言文化环境 中才能具有正确的、合乎文化背景的义项。 王佐良先生指出（1989），翻译不仅涉及语言问题，也涉及文化问题。译者不仅要了解外国的文化，还要深入了解自己民族的文化。 不仅如此，还要不断的将两种文化加以比较，因为真正的对等应该是在各自文化中的含义、作用、范围、感情色彩、影响等等都是相当的。 翻译者必须是一个真正意义的文化人。人们会说：他必须掌握两种语言；确实如此，但是不了解语言当中的文化，谁也无法真正掌握语言。 1.1.3 文学角度对翻译的定义 持文学观点的翻译工作者认为，翻译是对语言的艺术性创造，或是一种善于创造的艺术。一些西方学者也认为，翻译是对“原文本的 艺术性改写”。 文学翻译的任务时要把原作中包含的一定社会生活的映像完好无损地从一种语言移注到另一种语言中，在翻译过程中追求语言的艺术 美，再现原作的艺术性。用矛盾的话说，是“使读者在读译文的时候能够像读原著一样得到启发、感动和美的感受。” 语言是塑造文学形象的工具，因而文学的形象性特征必然要在语言上表现出来。文学语言的特征，诸如形象、生动、鲜明、含蓄、凝