机械类外文文献翻译
机械专业外文文献翻译
翻译部分英文原文High-speed machining and demand for the development ofHigh-speed machining is contemporary advanced manufacturing technology an important component of the high-efficiency, High-precision and high surface quality, and other features. This article presents the technical definition of the current state of development of China's application fields and the demand situation.High-speed machining is oriented to the 21st century a new high-tech, high-efficiency, High-precision and high surface quality as a basic feature, in the automobile industry, aerospace, Die Manufacturing and instrumentation industries gained increasingly widespread application, and has made significant technical and economic benefits. contemporary advanced manufacturing technology an important component part.HSC is to achieve high efficiency of the core technology manufacturers, intensive processes and equipment packaged so that it has a high production efficiency. It can be said that the high-speed machining is an increase in the quantity of equipment significantly improve processing efficiency essential to the technology. High-speed machining is the major advantages : improve production efficiency, improve accuracy and reduce the processing of cutting resistance.The high-speed machining of meaning, at present there is no uniform understanding, there are generally several points as follows : high cutting speed. usually faster than that of their normal cutting 5 -10 times; machine tool spindle speed high, generally spindle speed in -20000r/min above 10,000 for high-speed cutting; Feed at high velocity, usually 15 -50m/min up to 90m/min; For different cutting materials and the wiring used the tool material, high-speed cutting the meaning is not necessarily the same; Cutting process, bladed through frequency (Tooth Passing Frequency) closer to the "machine-tool - Workpiece "system the dominant natural frequency (Dominant Natural Frequency), can be considered to be high-speed cutting. Visibility high-speed machining is a comprehensive concept.1992. Germany, the Darmstadt University of Technology, Professor H. Schulz in the 52th on the increase of high-speed cutting for the concept and the scope, as shown in Figure 1. Think different cutting targets, shown in the figure of the transition area (Transition), to be what is commonly called the high-speed cutting, This is also the time of metal cutting process related to the technical staff are looking forward to, or is expected to achieve the cutting speed.High-speed machining of machine tools, knives and cutting process, and other aspects specific requirements. Several were from the following aspects : high-speed machining technology development status and trends.At this stage, in order to achieve high-speed machining, general wiring with high flexibility of high-speed CNC machine tools, machining centers, By using a dedicated high-speed milling, drilling. These equipment in common is : We must also have high-speed and high-speed spindle system feeding system, Cutting can be achieved in high-speed process. High-speed cutting with the traditional cutting the biggest difference is that "Machine-tool-workpiece" the dynamic characteristics of cutting performance is stronger influence. In the system, the machine spindle stiffness, grip or form, a long knife set, spindle Broach, torque tool set, Performance high-speed impact are important factors.In the high-speed cutting, material removal rate (Metal Removal Rate, MRR), unit time that the material was removed volume, usually based on the "machine-tool-workpiece" whether Processing System "chatter." Therefore, in order to satisfy the high-speed machining needs, we must first improve the static and dynamic stiffness of machine spindle is particularly the stiffness characteristics. HSC reason at this stage to be successful, a very crucial factor is the dynamic characteristics of the master and processing capability.In order to better describe the machine spindle stiffness characteristics of the project presented new dimensionless parameter - DN value, used for the evaluation of the machine tool spindle structure on the high-speed machining of adaptability. DN value of the so-called "axis diameter per minute speed with the product." The newly developed spindle machining center DN values have been great over one million. To reduce the weight bearing, but also with an array of steel products than to the much more light ceramic ball bearings; Bearing Lubrication most impressive manner mixed with oil lubrication methods. In the field of high-speed machining. have air bearings and the development of magnetic bearings and magnetic bearings and air bearings combined constitute the magnetic gas / air mixing spindle.Feed the machine sector, high-speed machining used in the feed drive is usually larger lead, multiple high-speed ball screw and ball array of small-diameter silicon nitride (Si3N4) ceramic ball, to reduce its centrifugal and gyroscopic torque; By using hollow-cooling technology to reduce operating at high speed ball screw as temperature generated by the friction between the lead screw and thermal deformation.In recent years, the use of linear motor-driven high-speed system of up to'' Such feed system has removed the motor from workstations to Slide in the middle of all mechanical transmission links, Implementation of Machine Tool Feed System of zero transmission. Because no linear motor rotating components, from the role of centrifugal force, can greatly increase the feed rate. Linear Motor Another major advantage of the trip is unrestricted. The linear motor is a very time for a continuous machine shop in possession of the bed. Resurfacing of the very meeting where avery early stage movement can go, but the whole system of up to the stiffness without any influence. By using high-speed screw, or linear motor can greatly enhance machine system of up to the rapid response. The maximum acceleration linear motors up to 2-10G (G for the acceleration of gravity), the largest feed rate of up to 60 -200m/min or higher.2002 world-renowned Shanghai Pudong maglev train project of maglev track steel processing, Using the Shenyang Machine Tool Group Holdings Limited McNair friendship company production plants into extra-long high-speed system for large-scale processing centers achieve . The machine feeding system for the linear guide and rack gear drive, the largest table feed rate of 60 m / min, Quick trip of 100 m / min, 2 g acceleration, maximum speed spindle 20000 r / min, the main motor power 80 kW. X-axis distance of up to 30 m, 25 m cutting long maglev track steel error is less than 0.15 mm. Maglev trains for the smooth completion of the project provided a strong guarantee for technologyIn addition, the campaign machine performance will also directly affect the processing efficiency and accuracy of processing. Mold and the free surface of high-speed machining, the main wiring with small cut deep into methods for processing. Machine requirements in the feed rate conditions, should have high-precision positioning functions andhigh-precision interpolation function, especially high-precision arc interpolation. Arc processing is to adopt legislation or thread milling cutter mold or machining parts, the essential processing methods. Cutting Tools Tool Material developmenthigh-speed cutting and technological development of the history, tool material is continuous progress of history. The representation ofhigh-speed cutting tool material is cubic boron nitride (CBN). Face Milling Cutter use of CBN, its cutting speed can be as high as 5000 m / min, mainly for the gray cast iron machining. Polycrystalline diamond (PCD) has been described as a tool of the 21st century tool, It is particularly applicable to the cutting aluminum alloy containing silica material, which is light weight metal materials, high strength, widely used in the automobile, motorcycle engine, electronic devices shell, the base, and so on. At present, the use of polycrystalline diamond cutter Face Milling alloy, 5000m/min the cutting speed has reached a practical level. In addition ceramic tool also applies to gray iron of high-speed machining; Tool Coating : CBN and diamond cutter, despite good high-speed performance, but the cost is relatively high. Using the coating technology to make cutting tool is the low price, with excellent mechanical properties, which can effectively reduce the cost. Now high-speed processing of milling cutter, with most of the wiring between the Ti-A1-N composite technology for the way of multi-processing, If present in the non-ferrous metal or alloy material dry cutting, DLC (Diamond Like Carbon) coating on thecutter was of great concern. It is expected that the market outlook is very significant;Tool clamping system : Tool clamping system to support high-speed cutting is an important technology, Currently the most widely used is a two-faced tool clamping system. Has been formally invested as a commodity market at the same clamping tool system are : HSK, KM, Bigplus. NC5, AHO systems. In the high-speed machining, tool and fixture rotary performance of the balance not only affects the precision machining and tool life. it will also affect the life of machine tools. So, the choice of tool system, it should be a balanced selection of good products.Process ParametersCutting speed of high-speed processing of conventional shear velocity of about 10 times. For every tooth cutter feed rate remained basically unchanged, to guarantee parts machining precision, surface quality and durability of the tool, Feed volume will also be a corresponding increase about 10 times, reaching 60 m / min, Some even as high as 120 m / min. Therefore, high-speed machining is usually preclude the use of high-speed, feed and depth of cut small cutting parameters. Due to the high-speed machining cutting cushion tend to be small, the formation of very thin chip light, Cutting put the heat away quickly; If the wiring using a new thermal stability better tool materials and coatings, Using the dry cutting process for high-speed machining is the ideal technology program. High-speed machining field of applicationFlexible efficient production lineTo adapt to the needs of new models, auto body panel molds andresin-prevention block the forming die. must shorten the production cycle and reduce the cost of production and, therefore, we must make great efforts to promote the production of high-speed die in the process. SAIC affiliated with the company that : Compared to the past, finishing, further precision; the same time, the surface roughness must be met, the bending of precision, this should be subject to appropriate intensive manual processing. Due to the extremely high cutting speed, and the last finishing processes, the processing cycle should be greatly reduced. To play for machining centers and boring and milling machining center category represented by the high-speed machining technology and automatic tool change function of distinctions Potential to improve processing efficiency, the processing of complex parts used to be concentrated as much as possible the wiring process, that is a fixture in achieving multiple processes centralized processing and dilute the traditional cars, milling, boring, Thread processing different cutting the limits of technology, equipment and give full play to the high-speed cutting tool function, NC is currently raising machine efficiency and speed up product development in an effective way. Therefore, the proposed multi-purpose tool of the new requirements call for a tool to complete different partsof the machining processes, ATC reduce the number of ATC to save time, to reduce the quantity and tool inventory, and management to reduce production costs. More commonly used in a multifunctional Tool, milling, boring and milling, drilling milling, drilling-milling thread-range tool. At the same time, mass production line, against the use of technology requires the development of special tools, tool or a smart composite tool, improve processing efficiency and accuracy and reduced investment. In the high-speed cutting conditions, and some special tools can be part of the processing time to the original 1 / 10 below, results are quite remarkable. HSC has a lot of advantages such as : a large number of materials required resection of the workpiece with ultrafine, thin structure of the workpiece, Traditionally, the need to spend very long hours for processing mobile workpiece and the design of rapid change, short product life cycle of the workpiece, able to demonstrate high-speed cutting brought advantages.中文译文高速切削加工的发展及需求高速切削加工是当代先进制造技术的重要组成部分，拥有高效率、高精度及高表面质量等特征。
先进制造技术的新发展——机械类外文文献翻译、中英文翻译
外文原文：The new advanced manufacturing technology developmentAbstract : This paper has presented the problems facing today's manufacturing technology, advanced manufacturing discussed in the forefront of science, and a vision for the future development of advanced manufacturing technology.Keyword：Advanced manufacturing technologies; Frontier science; Applications prospectsModern manufacturing is an important pillar of the national economy and overall national strength and its GDP accounted for a general national GDP 20%~55%. In the composition of a country's business productivity, manufacturing technology around 60% of the general role. Experts believe that the various countries in the world economic competition, mainly manufacturing technology competition. Their competitiveness in the production of the final product market share. With the rapid economic and technological development and customer needs and the changing market environment, this competition is becoming increasingly fierce, and that Governments attach great importance to the advanced manufacturing technology research.1 .Current manufacturing science to solve problemsManufacturing science to solve the current problems focused on the following aspects :(1) Manufacturing systems is a complex systems, and manufacturing systems to meet both agility, rapid response and rapid reorganization of the capacity to learn from the information science, life science and social science interdisciplinary research, and explore new manufacturing system architecture, manufacturing models and manufacturing systems effective operational mechanism. Manufacturing systems optimized organizational structure and good performance is manufacturing system modelling, simulation and optimization of the main objectives. Manufacturing system architecture not only to create new enterprises both agility and responsiveness to theneeds and the ability to reorganize significance, but also for the soft production equipment manufacturing enterprises bottom reorganization and dynamic capacity to set higher demands. Biological manufacturing outlook increasingly being introduced to the system to meet new demands manufacturing systems.(2) The rapid rise in support of manufacturing, geometric knowledge sharing has become a modern manufacturing constraints, product development and manufacturing technologies of the key issues. For example, in computer-aided design and manufacturing (CAD/CAM) integration, coordinates measurements (CMM) and robotics fields, in 3D real space (3-Real Space), there are a lot of geometric algorithm design and analysis, especially the geometric said, geometric calculation and geometric reasoning; In measurement and robot path planning and parts search spaces (such as Localization), the existence of space C- interspace (configuration space Configuration Space) geometric calculation and geometric reasoning; Objects in operation (rescue, paying and assembly, etc.) means paying more description and robot planning, campaign planning and assembly operations planning is needed in the types of space (Screw Space) geometric reasoning. Manufacturing process of physical and geometric mechanics phenomenon of scientific research to create a geometric calculation and geometric reasoning, and other aspects of the research topic, the theory pending further breakthrough, the new one door disciplines -- computer geometric are being increasingly broad and in-depth study.(3) In the modern manufacturing process, information not only manufacturing industries have become dominated the decisive factor, but also the most active ones. Manufacturing information systems to improve throughput of modern manufacturing has become a focus of scientific development. The manufacturing information system organization and structure required to create information access, integration and integration show three-dimensional in nature, measuring the multidimensional nature of the information, and information organizations nature. Information structure models in the manufacturing, manufacturing information consistency constraint, and the dissemination of data processing and the manufacture of enormous knowledge base management, and other areas, there is a need to further breakthroughs.(4) The calculation of the wisdom of artificial intelligence tools and methods in the manufacture of a wide range of applications for manufacturing smart development. Category based on the calculation of biological evolution algorithms smart tools, including activation issues optimize GPS technology portfolio by growing concern is in the manufacture of the complete portfolio optimization problems combined speed and precision of GPS issues both in size constraints. Manufacturing wisdom manifested in the following aspects : wisdom activation, wisdom design, intelligent processing, robotics, intelligent control, intelligent process planning, smart diagnostic, and other aspects. These innovative products are the key theoretical issues, but also by creating a door for a science skills in the important basic issues. The focus in these issues, we can form the basis of product innovation research system.2. Modern mechanical engineering at the frontiers of scienceCross-integration between the different science will produce new scientific gathering, economic development and social progress of science and technology created new demands and expectations, thus creating a frontier science. Frontier science is settled and unsettled issues between the scientific community. Frontier science, with a clear domain, and dynamic character of the area. Works frontier science from the general basic science is an important characteristic of the actual works, it covers the key emerging science and technology issues. Ultrasonic electrical, ultra-high-speed machines, green design and manufacturing, and other fields, and has done a lot of research work, but innovation is the key question is not clear mechanical science. Large complex mechanical system design and performance optimization of product innovation design, smart structures and systems, intelligent robots and their dynamics, nano Mocaxue, manufacturing process 3D numerical simulations and physical simulation, precision and ultra-fine processing technology key basis, about 10 mega large and sophisticated equipment design and manufacturing base, virtual manufacturing and virtual instruments, nanometer measurement and instrumentation, parallel connection axis machine tools, and although the field of micro-electromechanical systems have done a lot of research, but there are still many key science and technology issues to be resolved. Information science, nanoscience, materials science, life science, management science and manufacturing science of the 21st century will be to change the mainstream science, and the resulting high-tech industry will change the face of the world. Therefore, the above areas of cross-development manufacturing systems and manufacturing informatics, nano manufacturing machinery and nano science, better machinery and better manufacturing science, management science and manufacturing systems will be critical to the 21st century mechanical engineering science is important frontier science.2.1 Manufacturing science and information science cross -- manufacturing informaticsMechanical and electrical products, chemical raw materials in the information. Many modern value added products primarily reflected in the information. Thus the manufacturing process for the acquisition and application of information is very important. Information science and technology is to create an important symbol of globalization and modernization. While the manufacturing technology began to explore product design and manufacturing processes, the nature of the information, on the other hand, to create technology to transform itself to adapt to the new information makes its manufacturing environment. Along with the manufacturing process and manufacturing systems to deepen understanding, researchers are trying to new concepts and approaches to their description and expression to achieve further control and optimization purposes.And manufacturing-related information mainly product information, technical information and information management in this area following major research direction and content :(1) manufacturing information acquisition, processing, storage, transmission and application of knowledge to create information and decision-making transformation.(2) Non-symbols expressing information, manufacturing information enables transmission, manufacturing information management, manufacturing information integrity in a state of non-production decision-making, management of virtual manufacturing, based on the network environment of the design and manufacturing,manufacturing process control and manufacturing systems science. These elements are manufactured in science and the scientific basis for the integration of product information, constitute the manufacture of the new branch of science -- to create informatics.2.2 Micro mechanical and manufacturing technology researchMicro-electronic mechanical systems (MEMS) refers to the collection of micro-sensors, micro-devices and the implementation of signal processing and control circuits, interface circuits, communications and power with the integration of micro-electromechanical system integrity. MEMS technology objectives through system miniaturization, to explore a new theory of integration, new functional components and systems. MEMS development will greatly facilitate the pocket of various products, miniaturization, a number of devices and systems to enhance the level of functional density, information density and Internet density, significantly saving, thin section. Not only can it reduce the cost of mechanical and electrical systems, but also to be completed and the size of many large systems impossible task. For example, using sophisticated 5μm diameter micro tweezers walls are made of a red blood cell can; Created to keep the cars 3mm size; In the magnetic field, like butterflies flying size aircraft. MEMS technology has opened up a completely new technology areas and industries, with many traditional sensors incomparable advantages in manufacturing, aerospace, transportation, telecommunications, agriculture, biomedical, environmental monitoring, military, families, and access to almost all areas have very broad application prospects.Micro machinery is machinery and electronic technology in nano-scale technology integration photogenic product. Back in 1959 scientists have raised the idea of micro-mechanical and micro-1962, the first silicon pressure sensors. 1987 California University of California Berkeley developed rotor diameter of the silicon micro-60~120 16ug m electrostatic electric motors, show produced using silicon micro-machining small movable structures and compatible with IC manufacturing micro system potential. Micro-mechanical technology might like 20th century microelectronics technology, the technology of the world in the 21st century,economic development and national defense building a tremendous impact. Over the past 10 years, the development of micro-mechanical spectacular. Its characteristics are as follows : a considerable number of micro-components (micro structure, the implementation of micro-sensors and micro-machines, etc.) and micro-systems research success reflects the current and potential applications of value; The development of micro-manufacturing technology, particularly semiconductor processing technology have become small micro systems support technology; micro-electromechanical systems research needs of the interdisciplinary research team, micro-electromechanical systems technology in the development of microelectronics technology on the basis of multidisciplinary cross-frontier area of research, involving electronic engineering, mechanical engineering, materials engineering, physics, chemistry and biomedical engineering and other technical and scientific.The current micro-mechanical systems under the conditions of the campaign laws, the physical characteristics and micro components of the role of the mechanics payload acts lack adequate understanding is not yet in a theoretical basis for a micro-system design theory and methodology, and therefore can By experience and test methods research. Micro-mechanical systems, the existence of key scientific research issues of micro-scale system effects, physical properties and biochemical characteristics. Micro-system research are in the eve of a breakthrough, which is the in-depth study of the area.2.3 Material produced / manufactured parts integration of new technologies for processing.Material is a milestone in the progress of mankind, is the manufacturing and high-tech development. Every important to the success of the production and application of new materials, will promote the material and the promotion of national economic strength and military strength. 21, the world will be resource consumption-based economy to a knowledge-based industrial transformation for materials and parts and functions of a high performance, intelligent features; Request materials and components designed to achieve quantitative-based and digitized; Prepare materials and components for the rapid, efficient and achieve both integrationand integrated. Digital materials and components designed to be a simulation and optimization of materials and components to achieve high quality production / manufacturing and other integration, integrated manufacturing key. On the one hand, to be completed through computer simulation optimization can reduce the material is produced in the course of manufacture of spare parts and experimental links to the best craft programmes, materials and components to achieve high quality production / manufacturing; On the other hand, according to the requirements of different material properties, such as flexible modules volume, thermal expansion coefficient, magnetic performance, Research materials and components designed form. And the removal of traditional materials-manufacturing technology, and increase the level of information technology, the research group of synthetic materials is a process technology. Forming materials and components manufacture digital theory, technology and methods, such as rapid adoption of emerging technologies material growing principles, a breakthrough in the traditional law and to build law mechanical deformation processing many restrictions, no processing tools or dies, can rapidly create arbitrary complex shape and has a certain function 3D models or entity parts.2.4 machinery manufacturing breakthroughThe 21st century will be the century of life science, mechanical and life sciences depth integration will generate new concept products (such as better intelligence structure), to develop a new process (such as the growth processes shape) and the opening of new industries and to resolve product design, manufacturing processes and systems provide a series of problems new solutions. This is a highly innovative and leading edge area in the challenge.Earth's biological evolution in the long accumulated fine qualities of human manufacturing activities to address the various problems with examples and guidelines. Learning from life phenomena organizations operating complex systems and methods and techniques, manufacturing is the future solution to the current problems facing many an efficient way. Better manufacturing refers to the replication of biological organs from organizations, since healing, self growth and evolution since the function of the model structure and operation of a manufacturing system andmanufacturing process. If the manufacturing process mechanization, automation extends human physical and intelligent extension of the human intellectual, then "create better" may be said to extend its own organizational structure and human evolution process.Gene involved in the manufacture of biological science is the "self-organization" mechanism and its application in manufacturing systems. The so-called "self-organization" refers to a system in its internal mechanism driven by the organizational structure and operation mode learning, thereby enhancing the capacity for environmental adaptation process. Create better "since the organization" bottom-up mechanism for parallel product design and manufacturing processes of automatic generation, the dynamics of production systems and manufacturing systems and products more automatic a theoretical foundation and achieve superior conditions.Create a better manufacturing and life sciences "far edge hybrid" of the 21st century manufacturing will have an enormous impact. Create better research content is twofold :2.4.1 To create better livesResearch lives of the general phenomenon of the law and models, such as artificial life, cellular automatic machines, biological information processing skills, biological wisdom, biological-based organizational structure and mode of operation and the evolution of biological mechanisms and getting better;2.4.2 Oriented manufacturing breakthrough manufacturingResearch organizations better manufacturing systems since the mechanisms and methods, for example : based on full information-sharing breakthrough design principles, multi-discipline modules based on the distributed control and coordination mechanism based on the evolution of an excellent strategy; Study the concept of creating better system and its basis, such as : the formalization described space and better information shine upon relations better system and its evolution of complexity measurement methods.Machinery manufacturing is better and better mechanical science and life science, information science, materials science disciplines such as high integration, the studyincludes growth formative processes, better design and manufacturing systems, mechanical and biological wisdom better shape manufacturing. Currently doing research mostly forward exploratory work, with distinct characteristics of the basic research, if the research continues to seize opportunities that might arise revolutionary breakthroughs. Future research should concern areas of biological processing technology, better manufacturing system, based on rapid prototype manufacturing engineering technology organizations, as well as biological engineering related key technical basis.3. Modern manufacturing technology trendsSince the beginning of the 1990s, the nations of the world have manufacturing technology research and development as a national priority for the development of key technologies, such as the United States advanced manufacturing technology plan AMTP, Japan wisdom manufacturing technology (IMS) international cooperation schemes, Korea senior national plan of modern technology (G--7), Germany plans to manufacture 2000 and the EC Esprit and BRITE-EURAM plan.With the electronics, information, the constant development of new and high technologies, market demand individuality and diversity, the future of modern manufacturing technology to the overall development trends of the sophisticated, flexible, and networked, virtual and intelligent, green integrated, globalization direction.Current trends in modern manufacturing technology has the following nine areas :(1) Information technology, management techniques and technology closelyintegrated technology, modern production model will be continuous development.(2) Design techniques and more modern means.(3) Shaped and manufacture of sophisticated technology and manufacturingprocesses to achieve longer.(4) The formation of new special processing methods.(5) Development of a new generation of ultra-sophisticated, ultra-high-speedmanufacturing equipment.(6) Machining skills development for the engineering sciences.(7) Implementation of clean green manufacturing.(8)The widespread application of virtual reality technology to the manufacturingsector.(9) To create people-oriented.译文：先进制造技术的新发展摘要：本文介绍了当今制造技术面临的问题，论述了先进制造的前沿科学，并展望了先进制造技术的发展前景。
机械手臂应用领域的外文文献以及翻译
机械手臂应用领域的外文文献以及翻译1. Introduction机械手臂是一种用于执行各种任务的自动化设备，其应用领域广泛。
本文档提供了一些关于机械手臂应用领域的外文文献，并附有简要的翻译。
2. 文献1: "Advancements in Robotic Arm Control Systems"- Author: John Smith- Published: 2020这篇文献详细介绍了机械手臂控制系统的最新进展。
作者讨论了各种控制算法、传感器和执行器的应用，以提高机械手臂的性能和精确度。
3. 文献2: "Applications of Robotic Arms in Manufacturing Industry"- Author: Emily Chen- Published: 2018作者在这篇文献中研究了机械手臂在制造业中的应用。
她列举了多个实例，包括机械手臂在装配、焊接和搬运等任务中的应用，以及通过使用机械手臂能够提高生产效率和质量的案例。
4. 文献3: "Robot-Assisted Surgery: The Future of Medical Industry"- Author: David Johnson- Published: 2019这篇文献探讨了机械手臂在医疗行业中的应用，特别是机器人辅助外科手术。
作者解释了机械手臂在手术过程中的优势，包括更小的切口、更高的精确度和减少术后恢复时间等方面。
5. 文献4: "Exploring the Potential of Robotic Arms in Agriculture"- Author: Maria Rodriguez- Published: 2021这篇文献研究了机械手臂在农业领域的潜力。
作者探讨了机械手臂在种植、收割和除草等农业任务中的应用，以及如何通过机械化技术改善农业生产的效率和可持续性。
机械工程专业外文文献及翻译
机械工程专业外文文献及翻译文献一（外文标题）
摘要：
该文献研究了机械工程领域中的某个具体问题。
通过实验方法和数学模型的分析，作者得出了一些有意义的结论。
本文介绍了作者的研究方法和结果，并讨论了其在机械工程领域的应用前景。
翻译：
（将文献的主要内容用简洁准确的语言翻译成中文）
文献二（外文标题）
摘要：
该文献探讨了机械工程领域中的另一个重要问题。
通过实证分析和理论推导，作者提出了解决方案，并对其进行了验证。
本文阐述了作者的方法和实验结果，并探讨了其在实践中的应用潜力。
翻译：
（将文献的主要内容用简洁准确的语言翻译成中文）
文献三（外文标题）
摘要：
该文献研究了机械工程领域中的另一个新颖课题。
作者通过数
值模拟和实验验证，得出了一些有趣的发现。
本文介绍了作者的研
究过程和结果，并讨论了其对机械工程领域的影响。
翻译：
（将文献的主要内容用简洁准确的语言翻译成中文）
总结
本文档介绍了三篇机械工程专业的外文文献，包括摘要和翻译。
这些文献都对机械工程领域中的不同问题进行了研究，并提出了相
关的解决方案和发现。
希望这些文献能为机械工程专业的学生和研
究人员提供有价值的参考和启发。
机械手臂外文文献翻译、中英文翻译、外文翻译
机械手臂外文文献翻译、中英文翻译、外文翻译外文出处：《Manufacturing Engineering and Technology—Machining》附件1：外文原文XXXRobot XXX decades as high-XXX branch of industrial robots. It features can be programmed to perform tasks in a variety of expectations, in both structure and performance advantages of their own people and machines, in particular, XXX the work in the field of national economy and there are broad prospects for development. With the development of industrial automation, there has been CNC machining center, it is in reducing labor intensity, XXX, the upper and lower common in CNC machining processesmaterial, usually still use XXX relay-controlled semi-automatic device. The former time-consuming and labor intensive, inefficient; XXX, require more relays, XXX, XXX interference, XXX, XXX Programmable Logic Controller PLC-controlled robot control system formaterials up and down movement is simple, circuit design is reasonable, with a strong anti-jamming capability, ensuring the system'XXX, reduced maintenance rate,and XXXmechanics, mechanics, XXX, XXX, XXX and other fields of science, is a cross-disciplinary XXX.First, an overview of industrial manipulatorRobot is a kind of positioning control can be automated and can be re-programmedto change in multi-functional machine, which has multiple degrees of freedom can beused to carry an object in order to XXX China, plastic products industry, although still a labor-intensive, XXX1Europe and the United XXX, XXX-intensive South China, East China's coastal areas, XXX, because they have to face a high turnover rate of workers, as well as for theworkers to pay work-related injuries XXX.With the rapid development of China's industrial production, especially the reformand XXX workpiece handling, steering, XXX brazing, spray gun, wrenches and other tools for processing and assembly operations since, which has more and more attracted our attention. Robot is to imitate the manual part of the action,according toa given program, track and requirements for automatic capture, XXX.In real life, you will find this a problem. In the machine shop, the processing of parts loading time is not annoying, and labor productivity is not high, the cost of production major, and sometimes man-made incidents will occur, resulting in processing wereinjured. Think about what could replace it with the processing time of a tour as long as there are a few people, and can operate 24 hours saturated human right? The answeris yes, but the robot can come to replace it.XXX can increase XXX; XXX, ensuring product quality, to achieve safe production; particularly in the high-temperature, high pressure, low temperature, low pressure, dust, explosive, XXX the normal working people. Here I would like to think of designing a robot tobe used in actual production.XXX power: pneumatic robot refersto the compressed air as power source-driven robot. With pressure-driven and other energy-driven comparison have the following advantages: 1. Air inexhaustible, used XXX, does not require recycling and disposal,do not pollute the XXX. (Concept of environmental protection) 2. Air stick is small, the pi2peline pressure loss is small (typically less than asphalt gas path pressure drop of one-thousandth), to facilitate long-distance transport. 3. Compressed air of the working pressure is low (usually 4 to 8 kg / per square centimeter), and therefore moving the material components and XXX. With the hydraulic transmission, compared to its faster action and reaction, which is one of the advantages pneumatic outstanding. 5. The air cleaner media, it will not degenerate, not easy to plug the pipeline. But there are also places where it fly in the ointment: 1. As the compressibility of air, XXX the work, XXX as the precision of the velocity and not easily controlled. 2. As the use of low atmospheric pressure, the output power can not be too large; in order to increase the output power is bound to the structure of the entire pneumatic system size increased.With pneumatic drive and compare with other energy sources drive has the following advantages:Air inexhaustible, used XXX, without recycling anddisposal, do not pollute the XXX or a small amount of leakage would not be a XXX of air is small, the pipeline pressure loss also is very small, easy long-distance transport.The lower working pressure of compressed air, XXX general, reciprocating thrust in 1 to 2 tons XXX.Compared with the hydraulic transmission, and its faster action and reaction, XXX.Clean air medium, it will not degenerate, not easy to plug the pipeline. It can be safely used in flammable, XXX.Second, XXX, mechanical handRobot in the form of a variety of forms, some relatively simple, some more complicated, but the basic form is the same as the composition of the , Usually by the implementing agencies, transmission systems, control systems and auxiliary devices compose3d.1.Implementing agenciesXXX hands, wrists, arms, pillars. Hands are crawling institutions, is used to clamp and release the workpiece, and similar to human fingers, XXXXXX used to support the arm can also be made mobile as needed.2. TransmissionXXX, hydraulic transmission, XXX.3. Control SystemManipulator control system's main role is to control the robot according to certain procedures, direction, position, speed of action, a simple mechanical hand is generallynot set up a dedicated control system, using only trip switches, relays, control valves and circuits can be achieved dynamic drive system control, so that XXX of action. Action will have to use complex programmable robot controller, the micro-computer control.Three, XXX characteristicsXXX: the first is the general machinerydoes not require manual hand. It is an independent not affiliated with a particular hostdevice. It can be programmed according to the needs of thetask to complete the operation of the provisions. It is XXX, alsohas general machinery, memory, XXX second categoryis the need to manually do it, called the operation of aircraft. It originated in the atom,military industry, first through the operation of machines to complete a particular job,XXX such as the Moon. Used in industrial manipulator also fall into this category. The third category is dedicated manipulator, the XXX auto4matic lines, to solve the machine up and down the XXX known as the "Mechanical Hand", which is the host of services, from the host-driven; exception of a few outside the XXX, XXX.Main features:First, mechanical hand (the upper and lower material robot, assembly robot, handling robot, stacking robot, help robot, vacuum handling machines, vacuum suction crane,labor-saving spreader, pneumatic balancer, etc.).Second, cantilever cranes (cantilever crane, electric chain hoist crane, air balance the hanging, etc.)Third, rail-type transport system (hanging rail, light rail, single girder cranes, double-beam crane)Four, industrial machinery, application of handXXX of the production process developed a new type of device. In recent years, as electronic technology, especially computer extensive use of robot development and production of high-tech fields has XXX, XXX, XXX.Although the robot is not as flexible as staff, but it has to the continuous duplicationof work and labor, I do not know fatigue, not afraid of danger, XXX characteristics when compared with manual large, therefore, mechanical hand has been of great importance to many sectors, and increasingly has been applied widely, forexample:(1) Machining the workpiece loading and unloading, especially in the automatic lathe, combination machine tool use is more common.(2) XXX industry, it can beused to assemble printed circuit boards, XXX industry It can be used to assemble parts and components.(3) The working conditions may be poor, monotonous, repetitive easy to sub-fatigu5XXX.(4) XXX, XXX, XXX..(5) XXX.(6), XXX and testing.Help mechanical hands: also known as the balancer, balance suspended, labor-savingspreader, manual Transfer machine is a kind of weightlessness of manual load system,a novel, time-XXX,belonging to kinds of non-standard design of series products. Customer application needs, XXX of the automatic machinery, it can be a fixed program draws﹑XXX. Application of robot can replace the peopleengaged in monotonous﹑XXX, XXX of production, instead of people in hazardous XXX, XXX personal safety. The late 20th century, 40, the United XXX experiments, the first use of radioactive material handling robot, human robot in a safe room to XXX 50 years later, XXX, for the temperatures, polluted areas, and loading and unloading to take place the work piece material, but also as an auxiliary device in automaticmachine tools, machine tools, automatic production lines and processing center applications, the completion of the upper and lower material, or From the library take place XXX operation. Robot body mainly by the hand and sports XXX with the use of hands and operation of objects of different occasions, often there are clamping﹑XXX﹑﹑XXX﹑XXX, generally 2 to 3 degrees of XXX industry, machinery manufacture, XXX some of the staff and arm motor function, a fixd procedure for the captu6re, handling objects or operating tools, automatic operation device. It can replace human labor in order to achieve the production of heavy XXX the personal safety, which is XXX, metallurgy, electronics, light industry and nuclear power sectors. Mechanical hand tools or other XXX used for additional devices, such as the automatic machines or automatic production line handling and transmission of the workpiece, XXX centers, etc. generally do not have a separate control device. Some operating devices XXX.XXX and sports XXX. Task of hand is holding the workpiece (or tool) components, according to grasping objects by shape, size,weight, material and XXX structural forms, such as clamp type,type and adsorption-based care such as holding. Sports organizations, XXX (swing), XXX the required action, to change the location of objects by grasping and posture.Robot is the automated production of a kind used in the process of crawling and moving piece features automatic device, which is XXX a new type of device. In recent years, as electronic technology, especially computer extensive use of robot development and production of high-tech fields has XXX, XXX, XXX. Robot can replace humans completed the risk of duplication ofboring work, to reduce human XXX widely, in the machinery industry, it can be used for parts assembly, work piece handling, loading and unloadingXXX component of the FMC. The machine tool equip7XXX a flexible manufacturing cell, it was adapted to small and medium volume production, you can save a huge amount of the work piece conveyor device, compact, and adaptable. When the work piece changes, flexible production system is very easy to change will help XXX, improve product quality, and better adapt to market XXX, China'XXX isa certain distance, application andindustrialization of the size of the low level of robot research and development of a direct impact on raising the level of automation in China, from the economy, XXX, the study of mechanical hand design is very meaningful.8附件1：外文资料翻译译文呆板手机械手是近几十年发展起来的一种高科技自动化生产设备。
机械设计外文文献翻译、中英文翻译
机械设计外文文献翻译、中英文翻译unavailable。
The first step in the design process is to define the problem and XXX are defined。
the designer can begin toXXX evaluated。
and the best one is XXX。
XXX.Mechanical DesignA XXX machines include engines。
turbines。
vehicles。
hoists。
printing presses。
washing machines。
and XXX and methods of design that apply to XXXXXX。
cams。
valves。
vessels。
and mixers.Design ProcessThe design process begins with a real need。
Existing apparatus may require XXX。
efficiency。
weight。
speed。
or cost。
while new apparatus may be XXX。
To start。
the designer must define the problem and XXX。
ideas and concepts are generated。
evaluated。
and refined until the best one is XXX。
XXX.XXX。
assembly。
XXX.During the preliminary design stage。
it is important to allow design XXX if some ideas may seem impractical。
they can be corrected early on in the design process。
机械设计理论外文翻译、中英文翻译、外文文献翻译
外文原文：Machine design theoryThe machine design is through designs the new product or improves the old product to meet the human need the application technical science. It involves the project technology each domain, mainly studies the product the size, the shape and the detailed structure basic idea, but also must study the product the personnel which in aspect the and so on manufacture, sale and use question.Carries on each kind of machine design work to be usually called designs the personnel or machine design engineer. The machine design is a creative work. Project engineer not only must have the creativity in the work, but also must in aspect and so on mechanical drawing, kinematics, engineering material, materials mechanics and machine manufacture technology has the deep elementary knowledge.If front sues, the machine design goal is the production can meet the human need the product. The invention, the discovery and technical knowledge itself certainly not necessarily can bring the advantage to the humanity, only has when they are applied can produce on the product the benefit. Thus, should realize to carries on before the design in a specific product, must first determine whether the people do need this kind of productThe machine design must regard as the machine design personnel carries on using creative ability the product design, the system analysis and a formulation product manufacture technology good opportunity. Grasps the project elementary knowledge to have to memorize some data and the formula is more important than. The merely service data and the formula is insufficient to the completely decision which makes in a good design needs. On the other hand, should be earnest precisely carries on all operations. For example, even if places wrong a decimal point position, also can cause the correct design to turn wrongly.A good personnel design should dare to propose the new idea. moreover is willing to undertake the certain risk, when the new method is not suitable, use original method. Therefore, designs the personnel to have to have to have the patience, because spends the time and the endeavor certainly cannot guarantee bringssuccessfully. A brand-new design, the request screen abandons absolutely many, knows very well the method for the people. Because many person of conservativeness does this certainly is not an easy matter. A mechanical designer should unceasingly explore the improvement existing product the method, should earnestly choose originally, the process confirmation principle of design in this process, with has not unified it after the confirmation new idea.Newly designs itself can have the question occurrence which many flaws and has not been able to expect, only has after these flaws and the question are solved, can manifest new goods come into the market the product superiority. Therefore, a performance superior product is born at the same time, also is following a higher risk. Should emphasize, if designs itself does not request to use the brand-new method, is not unnecessary merely for the goal which transform to use the new method.In the design preliminary stage, should allow to design the personnel fully to display the creativity, not each kind of restraint. Even if has had many impractical ideas, also can in the design early time, namely in front of the plan blueprint is corrected. Only then, only then does not send to stops up the innovation the mentality. Usually, must propose several sets of design proposals, them perform the comparison. Has the possibility very much in the plan which finally designated, has used certain not in plan some ideas which accepts.How does the psychologist frequently discuss causes the machine which the people adapts them to operated. Design personnel's basic responsibility is diligently causes the machine to adapt the people. This certainly is not an easy work, because certainly does not have to all people to say in fact all is the most superior operating area and the operating process.Another important question, project engineer must be able to carry on the exchange and the consultation with other concerned personnel. In the initial stage, designs the personnel to have to carry on the exchange and the consultation on the preliminary design with the administrative personnel, and is approved. This generally is through the oral discussion, the schematic diagram and the writing material carries on. In order to carry on the effective exchange, needs to solve the following problem:(1) Designs whether this product truly does need for the people? Whether there is competitive ability(2) Does this product compare with other companies'' existing similar products?(3) Produces this kind of product is whether economical?(4) Product service is whether convenient?(5) Product whether there is sale? Whether may gain?Only has the time to be able to produce the correct answer to above question. But, the product design, the manufacture and the sale only can in carry on to the above question preliminary affirmation answer foundation in. Project engineer also should through the detail drawing and the assembly drawing, carries on the consultation together with the branch of manufacture to the finally design proposal usually, can have some problem in the manufacture process. Possibly can request to some components size or the common difference makes some changes, causes the components the production to change easily. But, in the project change must have to pass through designs the personnel to authorize, guaranteed cannot damage the product the function. Sometimes, when in front of product assembly or in the packing foreign shipment experiment only then discovers in the design some kind of flaw. These instances exactly showed the design is a dynamic process. Always has a better method to complete the design work, designs the personnel to be supposed unceasingly diligently, seek these better methods.Recent year, the engineering material choice already appeared importantly. In addition, the choice process should be to the material continuously the unceasing again appraisal process. The new material unceasingly appears, but some original materials can obtain the quantity possibly can reduce. The environmental pollution, material recycling aspect and so on use, worker's health and security frequently can attach the new limiting condition to the choice of material. In order to reduce the weight or saves the energy, possibly can request the use different material. Comes from domestic and international competition, to product service maintenance convenience request enhancement and customer's aspect the and so on feedback pressure, can urge the people to carry on to the material reappraises. Because thematerial does not select when created the product responsibility lawsuit, has already had the profound influence. In addition, the material and between the material processing interdependence is already known by the people clearly. Therefore, in order to can and guarantees the quality in the reasonable cost under the premise to obtain satisfaction the result, project engineer makes engineers all to have earnestly carefully to choose, the determination and the use material.Makes any product the first step of work all is designs. Designs usually may divide into several explicit stages: (a) preliminary design; (b) functional design; (c) production design. In the preliminary design stage, the designer emphatically considered the product should have function. Usually must conceive and consider several plans, then decided this kind of thought is whether feasible; If is feasible, then should makes the further improvement to or several plans. In this stage, the question which only must consider about the choice of material is: Whether has the performance to conform to the request material to be possible to supply the choice; If no, whether has a bigger assurance all permits in the cost and the time in the limit develops one kind of new material.In the functional design and the engineering design stage, needs to make a practical feasible design. Must draw up the quite complete blueprint in this stage, chooses and determines each kind of components the material. Usually must make the prototype or the working model, and carries on the experiment to it, the appraisal product function, the reliability, the outward appearance and the service maintenance and so on. Although this kind of experiment possibly can indicate, enters in the product to the production base in front of, should replace certain materials, but, absolutely cannot this point take not earnestly chooses the material the excuse. Should unify the product the function, earnestly carefully considers the product the outward appearance, the cost and the reliability. Has the achievement very much the company when manufacture all prototypes, selects the material should the material which uses with its production in be same, and uses the similar manufacture technology as far as possible. Like this has the advantage very much to the company. The function complete prototype if cannot act according to the anticipated sales volume economically to make, or is prototypical and the official production installment has in the quality and the reliable aspect is very greatly different, then this kind of prototype does not have the great value. Project engineer is best can completely complete thematerial in this stage the analysis, the choice and the determination work, but is not remains it to the production design stage does. Because, is carries on in the production design stage material replacement by other people, these people are inferior to project engineer to the product all functions understanding. In the production design stage, is should completely determine with the material related main question the material, causes them to adapt with the existing equipment, can use the existing equipment economically to carry on the processing, moreover the material quantity can quite be easy to guarantee the supply. In the manufacture process, inevitably can appear to uses the material to make some changes the situation. The experience indicated that, may use certain cheap materials to take the substitute. However, in the majority situation, in will carry on the production later to change the material to have in to start before the production to change the price which the material will spend to have to be higher than. Completes the choice of material work in the design stage, may avoid the most such situations. Started after the production manufacture to appear has been possible to supply the use the new material is replaces the material the most common reason. Certainly, these new materials possibly reduce the cost, the improvement product performance. But, must carry on the earnest appraisal to the new material, guarantees .its all performance all to answer the purpose. Must remember that, the new material performance and the reliable very few pictures materials on hand such understood for the people. The majority of products expiration and the product accident caused by negligence case are because in selects the new material to take in front of substitution material, not truly understood their long-term operational performance causes.The product responsibility lawsuit forces designs the personnel and the company when the choice material, uses the best procedure. In the material process, five most common questions are: (a) did not understand or cannot use about the material application aspect most newly the best information paper; (b) has not been able to foresee and to consider the dusk year possible reasonable use (for example to have the possibility, designs the personnel also to be supposed further to forecast and the consideration because product application method not when creates consequence. recent years many products responsibilities lawsuit case, because wrongly uses the plaintiff which the product receives the injury to accuse produces the factory, and wins the decision); (c) uses the material data not entire perhaps some data are indefinite, works as its long-term performance data is the like this time in particular;(d) the quality control method is not suitable and not after the confirmation; (e) the personnel which completely is not competent for the post by some chooses the material.Through to the above five questions analysis, may obtain these questions is does not have the sufficient reason existence the conclusion. May for avoid these questions to these questions research analyses the appearance indicating the direction. Although uses the best choice of material method not to be able to avoid having the product responsibility lawsuit, designs the personnel and the industry carries on the choice of material according to the suitable procedure, may greatly reduce the lawsuit the quantity.May see from the above discussion, the choice material people should to the material nature, the characteristic and the processing method have comprehensive and the basic understanding.译文：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。
机械专业毕业设计外文翻译1
本科毕业设计（本科毕业论文）外文文献及译文文献、资料题目：High-rise Tower Crane designed文献、资料来源：期刊（著作、网络等）文献、资料发表（出版）日期：2000.3.25院（部）：机电工程学院专业：机电工程及自动化High-rise Tower Crane designed under Turbulent Winds At present, construction of tower cranes is an important transport operations lifting equipment, tower crane accident the people's livelihood, major hazards, and is currently a large number of tower crane drivers although there are job permits, due to the lack of means to monitor and review the actual work of a serious violation . Strengthen the inspection and assessment is very important. Tower crane tipping the cause of the accident can be divided into two aspects: on the one hand, as a result of the management of tower cranes in place, illegal operation, illegal overloading inclined cable-stayed suspended widespread phenomenon; Second, because of the tower crane safety can not be found in time For example,Took place in the tower crane foundation tilt, micro-cracks appear critical weld, bolts loosening the case of failure to make timely inspection, maintenance, resulting in the continued use of tower cranes in the process of further deterioration of the potential defect, eventually leading to the tower crane tipping. The current limit of tower crane and the black box and can not be found to connect slewing tower and high-strength bolts loosening tightened after the phenomenon is not timely, not tower verticality of the axis line of the lateral-line real-time measurement, do not have to fight the anti-rotation vehicles, lifting bodies plummeted Meng Fang, hook hoists inclined cable is a timely reminder and record of the function, the wind can not be contained in the state of suspended operation to prevent tipping on the necessary tips on site there is a general phenomenon of the overloaded overturning of the whole security risks can not be accurately given a reminder and so on, all of which the lease on the tower crane, use, management problems,Through the use of tower crane anti-tipping monitor to be resolved. Tower crane anti-tipping Monitor is a new high-tech security monitoring equipment, and its principle for the use of machine vision technology and image processing technology to achieve the measurement of the tilt tower, tower crane on the work of state or non-working state of a variety of reasons angle of the tower caused by the critical state to achieve the alarm, prompt drivers to stop illegal operation, a computer chip at the same time on the work of the state of tower crane be recorded. Tower crane at least 1 day overload condition occurs, a maximum number of days to reach 23 overloading, the driver to operate the process of playing the anti-car, stop hanging urgency, such as cable-stayed suspended oblique phenomenon often, after verification and education, to avoid the possible occurrence of fatal accidents. Wind conditions in the anti-tipping is particularly important, tower cranes sometimes connected with the pin hole and pin do not meet design requirements, to connect high-strength bolts are not loose in time after the tightening of the phenomenon, through timely maintenance in time after the tightening of the phenomenon, through timely maintenance and remedial measures to ensure that the safe and reliable construction progress. Reduced lateral line tower vertical axis measuring the number of degrees,Observation tower angle driver to go to work and organize the data once a month to ensure that the lateral body axis vertical line to meet the requirements, do not have to every time and professionals must be completed by Theodolite tower vertical axismeasuring the lateral line, simplified the management link. Data logging function to ensure that responsibility for the accident that the scientific nature to improve the management of data records for the tower crane tower crane life prediction and diagnosis of steel structures intact state data provides a basis for scientific management and proactive prevention of possible accidents, the most important thing is, if the joint use of the black box can be easily and realistically meet the current provisions of the country's related industries. Tower crane safety management at the scene of great importance occurred in the construction process should be to repair damaged steel, usually have to do a good job in the steel tower crane maintenance work and found that damage to steel structures, we must rule out potential causes of accidents, to ensure safety in production carried out smoothly. Tower crane in the building construction has become essential to the construction of mechanical equipment, tower crane at the construction site in the management of safety in production is extremely important. A long time, people in the maintenance of tower crane, only to drive attention to the conservation and electrical equipment at the expense of inspection and repair of steel structures, to bring all kinds of construction accidents.Conclusion: The tower crane anti-tipping trial monitor to eliminate potential causes of accidents to provide accurate and timely information, the tower crane to ensure the smooth development of the leasing business, the decision is correct, and should further strengthen and standardize the use of the environment (including new staff training and development of data processing system, etc.).The first construction cranes were probably invented by the Ancient Greeks and were powered by men or beasts of burden, such as donkeys. These cranes were used for the construction of tall buildings. Larger cranes were later developed, employing the use of human treadwheels, permitting the lifting of heavier weights. In the High Middle Ages, harbour cranes were introduced to load and unload ships and assist with their construction – some were built into stone towers for extra strength and stability. The earliest cranes were constructed from wood, but cast iron and steel took over with the coming of the Industrial Revolution.For many centuries, power was supplied by the physical exertion of men or animals, although hoists in watermills and windmills could be driven by the harnessed natural power. The first 'mechanical' power was provided by steam engines, the earliest steam crane being introduced in the 18th or 19th century, with many remaining in use well into the late 20th century. Modern cranes usually use internal combustion engines or electric motors and hydraulic systems to provide a much greater lifting capability than was previously possible, although manual cranes are still utilised where the provision of power would be uneconomic.Cranes exist in an enormous variety of forms – each tailored to a specific use. Sizes range from the smallest jib cranes, used inside workshops, to the tallest tower cranes,used for constructing high buildings, and the largest floating cranes, used to build oil rigs and salvage sunken ships.This article also covers lifting machines that do not strictly fit the above definition of a crane, but are generally known as cranes, such as stacker cranes and loader cranes.The crane for lifting heavy loads was invented by the Ancient Greeks in the late 6th century BC. The archaeological record shows that no later than c.515 BC distinctive cuttings for both lifting tongs and lewis irons begin to appear on stone blocks of Greek temples. Since these holes point at the use of a lifting device, and since they are to be found either above the center of gravity of the block, or in pairs equidistant from a point over the center of gravity, they are regarded by archaeologists as the positive evidence required for the existence of the crane.The introduction of the winch and pulley hoist soon lead to a widespread replacement of ramps as the main means of vertical motion. For the next two hundred years, Greek building sites witnessed a sharp drop in the weights handled, as the new lifting technique made the use of several smaller stones more practical than of fewer larger ones. In contrast to the archaic period with its tendency to ever-increasing block sizes, Greek temples of the classical age like the Parthenon invariably featured stone blocks weighing less than 15-20 tons. Also, the practice of erecting large monolithic columns was practically abandoned in favour of using several column drums.Although the exact circumstances of the shift from the ramp to the crane technology remain unclear, it has been argued that the volatile social and political conditions of Greece were more suitable to the employment of small, professional construction teams than of large bodies of unskilled labour, making the crane more preferable to the Greek polis than the more labour-intensive ramp which had been the norm in the autocratic societies of Egypt or Assyria.The first unequivocal literary evidence for the existence of the compound pulley system appears in the Mechanical Problems (Mech. 18, 853a32-853b13) attributed to Aristotle (384-322 BC), but perhaps composed at a slightly later date. Around the same time, block sizes at Greek temples began to match their archaic predecessors again, indicating that the more sophisticated compound pulley must have found its way to Greek construction sites by then.During the High Middle Ages, the treadwheel crane was reintroduced on a large scale after the technology had fallen into disuse in western Europe with the demise of the Western Roman Empire. The earliest reference to a treadwheel (magna rota) reappears in archival literature in France about 1225, followed by an illuminated depiction in a manuscript of probably also French origin dating to 1240. In navigation, the earliest uses of harbor cranes are documented for Utrecht in 1244, Antwerp in 1263, Brugge in 1288 and Hamburg in 1291, while in England the treadwheel is not recorded before 1331.Generally, vertical transport could be done more safely and inexpensively by cranes than by customary methods. Typical areas of application were harbors, mines, and, in particular, building sites where the treadwheel crane played a pivotal role in the construction of the lofty Gothic cathedrals. Nevertheless, both archival and pictorial sources of the time suggest that newly introduced machines like treadwheels or wheelbarrows did not completely replace more labor-intensive methods like ladders, hods and handbarrows. Rather, old and new machinery continued to coexist on medieval construction sites and harbors.Apart from treadwheels, medieval depictions also show cranes to be powered manually by windlasses with radiating spokes, cranks and by the 15th century also by windlasses shaped like a ship's wheel. To smooth out irregularities of impulse and get over 'dead-spots' in the lifting process flywheels are known to be in use as early as 1123.The exact process by which the treadwheel crane was reintroduced is not recorded, although its return to construction sites has undoubtedly to be viewed in close connection with the simultaneous rise of Gothic architecture. The reappearance of the treadwheel crane may have resulted from a technological development of the windlass from which the treadwheel structurally and mechanically evolved. Alternatively, the medieval treadwheel may represent a deliberate reinvention of its Roman counterpart drawn from Vitruvius' De architectura which was available in many monastic libraries. Its reintroduction may have been inspired, as well, by the observation of the labor-saving qualities of the waterwheel with which early treadwheels shared many structural similarities.In contrast to modern cranes, medieval cranes and hoists - much like their counterparts in Greece and Rome - were primarily capable of a vertical lift, and not used to move loads for a considerable distance horizontally as well. Accordingly, lifting work was organized at the workplace in a different way than today. In building construction, for example, it is assumed that the crane lifted the stone blocks either from the bottom directly into place, or from a place opposite the centre of the wall from where it could deliver the blocks for two teams working at each end of the wall. Additionally, the crane master who usually gave orders at the treadwheel workers from outside the crane was able to manipulate the movement laterally by a small rope attached to the load. Slewing cranes which allowed a rotation of the load and were thus particularly suited for dockside work appeared as early as 1340. While ashlar blocks were directly lifted by sling, lewis or devil's clamp (German Teufelskralle), other objects were placed before in containers like pallets, baskets, wooden boxes or barrels.It is noteworthy that medieval cranes rarely featured ratchets or brakes to forestall the load from running backward.[25] This curious absence is explained by the high friction force exercised by medieval treadwheels which normally prevented the wheel from accelerating beyond control.目前，塔式起重机是建筑工程进行起重运输作业的重要设备，塔机事故关系国计民生、危害重大，而目前众多的塔机司机虽然有上岗证，由于缺少监督和复核手段，实际工作中违规严重。