外文翻譯--關(guān)于機(jī)械【中英文文獻(xiàn)譯文】,中英文文獻(xiàn)譯文,外文,翻譯,關(guān)于,機(jī)械,中英文,文獻(xiàn),譯文 The machine Mechanical design is a through the design of new products or improving old products to meet the demand of human application science and technology. It involves field of engineering technology, main research product size, shape, the detailed structure basic idea, theproduct but also in the aspects of manufacture, sale and use question. Design personnel or machine design engineer is to point to in a variety of mechanical design work. Mechanical design is a creative work. They at work to not only creative and must be in mechanical drawing engineering material, materials mechanics and machine manufacture technology has the deep elementary knowledge. Mechanical design is the purpose of manufacturing products can satisfy human needs. Only when the invention, discovery, and knowledge of science and technology has been applied on tproducts to produce benefits benefits it brings to mankind. Thus, should realize before a good particular product to carry on the design, must first determine whether people need this product. Machinery and other components of the machine. It is a device used to convert transfer energy, for example: motor, worm gear machines, vehicles, cranes, printing machine, washing machine, camera, camera and so on. Many of the principles and the design method is suitable for the machine and the machine design. Terms of the meaning of "mechanical design" rather than "mechanical design" is more widely some, mechanism design, including mechanical design. Based on the analysis of motion and the design structure, want to the products and future maintenance in mechanical design must also be considered. In the field of mechanical engineering and other engineering fields, all of which need to mechanical equipment, such as switches, CAM, valves, vessels, mixer, etc. A complete machine design is a complicated process. Any product the first step is to choose the product in the design of each part of the composition of the material. Today's designers use many materials. Is very important for the function of the product, its appearance, material cost, manufacturing cost to make the necessary choices. On the material properties must be carefully assessed in advance. One of the first steps in the design of any product is to select the material from which each part is to be made. Numerous materials are available to today's designers. The function of the product, its appearance, the cost of the material, and the cost of fabrication are important in making a selection. A careful evaluation of the properties of a. material must be made prior to any calculations. In the force analysis of spur gears, the forces are assumed to act in a single plane.We shall study gears in which the forces have three dimensions. The reason for this ,in the case of helical gears, is that the teeth are not parallel to the axis of rotation. And in the case of bevel gears, the rotational axes are not parallel to each other. There are also other reasons, as we shall learn. Helical gears are used to transmit motion between parallel shafts. The helix angle is the same on each gear, but one gear must have a right-hand helix and the other a left-hand helix. The shape of the tooth is an involute helicoid. If a piece of paper cut in the shape of a parallelogram is wrapped around a cylinder, the angular edge of the paper becomes a helix. If we unwind this paper, each point on the angular edge generates an involute curve. The surface obtained when every point on the edge generates an involute is called an involute helicoid. The initial contact of spur-gear teeth is a line extending all the way across the face of the tooth. The initial contact of helical gear teeth is a point, which changes into a line as the teeth come into more engagement. In spur gears the line of contact is parallel to the axis of the rotation; in helical gears, the line is diagonal across the face of the tooth. It is this gradual of the teeth and the smooth transfer of load from one tooth to another, which give helical gears the ability to transmit heavy loads at high speeds. Helical gears subject the shaft bearings to both radial and thrust loads. When the thrust loads become high or are objectionable for other reasons, it may be desirable to use double helical gears. A double helical gear(herringbone) is equivalent to two helical gears of opposite hand, mounted side by side on the same shaft. They develop opposite thrust reactions and thus cancel out the thrust load. When two or more single helical gears are mounted on the same shaft,the hand of the gears should be selected so as to produce the minimum thrust load.Crossed-helical, or spiral, gears are those in which the shaft centerlines are neither parallel nor intersecting. The teeth of crossed-helical fears have point contact with each other, which changes to line contact as the gears wear in. For this reason they will carry out very small loads and are mainly for instrumental applications, and are definitely not recommended for use in the transmission of power.There is on difference between a crossed heli cal gear and a helical gear until they are mounted in mesh with each other. They are manufactured in the same way. A pair of meshed crossed helical gears usually have the same hand; that is ,a right-hand driver goes with a right-hand driven. In the design of crossed-helical gears, the minimum sliding velocity is obtained when the helix angle are equal. However, when the helix angle are not equal, the gear with the larger helix angle should be used as the driver if both gears have the same Hand. Worm gears are similar to crossed helical gears. The pinion or worm has a small number of teeth, usually one to four, and since they completely wrap around the pitch cylinder they are called threads. Its mating gear is called a worm gear, which is not a true helical gear. A worm and worm gear are used to provide a high angular-velocity reduction between nonintersecting shafts which are usually at right angle. The worm gear is not a helical gear because its face is made concave to fit the curvature of the worm in order to provide line contact instead of point contact. However, a disadvantage of worm gearing is the high sliding velocities across the teeth, the same as with crossed helical gears. Worm gearing are either single or double enveloping. A single-enveloping gearing is one in which the gear wraps around or partially encloses the worm.. A gearing in which each element partially encloses the other is, of course, a double-enveloping worm gearing. The important difference between the two is that area contact exists between the teeth of double-enveloping gears while only line contact between those of single-enveloping gears. The worm and worm gear of a set have the same hand of helix as for crossed helical gears, but the helix angles are usually quite different. The helix angle on the worm is generally quite large, and that on the gear very small. Because of this, it is usual to specify the lead angle on the worm, which is the complement of the worm helix angle, and the helix angle on the gear; the two angles are equal for a 90-deg. Shaft angle.When gears are to be used to transmit motion between intersecting shaft, some of bevel gear is required. Although bevel gear are usually made for a shaft angle of 90 deg. They may be produced for almost any shaft angle. The teeth may be cast, milled,or generated. Only the generated teeth may be classed as accurate. In a typical bevelgear mounting, one of the gear is often mounted outboard of the bearing. This means that shaft deflection can be more pronounced and have a greater effect on the contact of teeth. Another difficulty, which occurs in predicting the stress in bevel-gear teeth, is the fact the teeth are tapered. It is frequently desirable, as in the case of automotive differential applications, to have gearing similar to bevel gears but with the shaft offset. Such gears are called hypoid gears because their pitch surfaces are hyperboloids of revolution.The tooth action between such gears is a combination of rolling and sliding along a straight line and has much in common with that of worm gears. A shaft is a rotating or stationary member, usually of circular cross section, having mounted upon it such elementsas gears, pulleys, flywheels, cranks, sprockets, and other power-transmission elements. Shaft may be subjected to bending, tension, compression, or torsional loads, acting singly or in combination with one another. When they are combined, one may expect to find both static and fatigue strength to be important design considerations, since a single shaft may be subjected to staticstresses, completely reversed, and repeated stresses, all acting at the same time. The word “shaft” covers numerous variations, such as axles and spindles. Anaxle is a shaft, wither stationary or rotating, nor subjected to torsion load. A shirtrotating shaft is often called a spindle.When either the lateral or the torsional deflection of a shaft must be held to close limits, the shaft must be sized on the basis of deflection before analyzing the stresses. The reason for this is that, if the shaft is made stiff enough so that the deflection is not too large, it is probable that the resulting stresses will be safe. But by no means should the designer assume that they are safe; it is almost always necessary to calculate them so that he knows they are within acceptable limits. Whenever possible, the power-transmission elements, such as gears or pullets, should be located close to the supporting bearings, This reduces the bending moment, and hence the deflection and bending stress. Although the von Mises-Hencky-Goodman method is difficult to use in design of shaft, it probably comes closest to predicting actual failure. Thus it is a good way of checking a shaft that has already been designed or of discovering why a particular shaft has failed in service. Furthermore, there are a considerable number of shaft-design problems in which the dimension are pretty well limited by other considerations, such as rigidity, and it is only necessary for the designer to discover something about the fillet sizes, heat-treatment, and surface finish and whether or not shot peening is necessary in order to achieve the required life and reliability. Because of the similarity of their functions, clutches and brakes are treated together. In a simplified dynamic representation of a friction clutch, or brake,two inertias I1 and I2 traveling at the respective angular velocities W1 and W2, one of which may be zero in the case of brake, are to be brought to the same speed by engaging the clutch or brake. Slippage occurs because the two elements are running at different speeds and energy is dissipated during actuation, resulting in a temperature rise. In analyzing the performance of these devices we shall be interested in the actuating force, the torque transmitted, the energy loss and the temperature rise. The torque transmitted is related to the actuating force, the coefficient of friction, and the geometry of the clutch or brake. This is problem in static, which will have to be studied separately for eath geometric configuration. However, temperature rise is related to energy loss and can be studied without regard to the type of brake or clutch because the geometry of interest is the heat-dissipating surfaces. Have a shape as a processing method, all machining process for the production of the most commonly used and most important method. Machining process is a process generated shape, in this process, Drivers device on the workpiece material to bein the form of chip removal. Although in some occasions, the workpiece under no circumstances, the use of mobile equipment to the processing, However, the majority of the machining is not only supporting the workpiece also supporting tools and equipment to complete. Machining know the process has two aspects. Small group of low-cost production. For casting, forging and machining pressure, every production of a specific shape of the workpiece, even a spare parts, almost have to spend the high cost of processing. Welding to rely on the shape of the structure, to a large extent, depend on effective in the form of raw materials. In general, through the use of expensive equipment and without special processing conditions, can be almost any type of raw materials, mechanical processing to convert the raw materials processed into the arbitrary shape of the structure, as long as the external dimensions large enough, it is possible. Because of a production of spare parts, even when the parts and structure of the production batch sizes are suitable for the original casting, Forging or pressure processing to produce, but usually prefer machining. Strict precision and good surface finish, Machining the second purpose is the establishment of the high precision and surface finish possible on the basis of. Many parts, if any other means of production belonging to the large-scale production,Well Machining is a low-tolerance and can meet the requirements of small batch production. Besides, many parts on the production and processing of coarse process to improve its general shape of the surface. It is only necessary precision and choose only the surface machining. For instance, thread, in addition to mechanical processing, almost no other processing method for processing. Another example is the blacksmith pieces keyhole processing, as well as training to be conducted immediately after the mechanical completion of the processing. Primary Cutting Parameters Cutting the work piece and tool based on the basic relationship between the following four elements to fully describe : the tool geometry, cutting speed, feed rate, depth and penetration of a cutting tool. Cutting Tools must be of a suitable material to manufacture, it must be strong, tough, hard and wear-resistant. Tool geometry -- to the tip plane and cutter angle characteristics -- for each cutting process must be correct. Cutting speed is the cutting edge of work piece surface rate, it is inches per minute to show. In order to effectively processing, and cutting speed must adapt to the level of specific parts -- with knives. Generally, the more hard work piece material, the lower the rate. microscopic view of the necessity of From the micro perspective, CNC machine tools than traditional machines have the following prominent superiority, and these advantages are from the NC system includes computer power. can be processed by conventional machining is not the curve, surface and other complex parts .Because computers are superb computing power can be accurately calculated instantaneous each coordinate axis movement exercise should be instantaneous, it can compound into complex curves and surfaces. Automated processing can be achieved, but also flexible automation to increase machine efficiency than traditional 3 to 7 times. Because computers are memory and storage capacity, can be imported and stored procedures remember down, and then click procedural requirements to implement the order automatically to achieve automation. CNC machine tool as a replacement procedures, we can achieve another work piece machining automation, so that single pieces and small batch production can be automated, it has been called "flexible automation." High precision machining parts, the size dispersion of small, easy to assemble, no longer needed "repair." Processes can be realized more focused, in part to reduce the frequent removal machine. Have automatic alarm, automatic control, automatic compensation, and other self-regulatory functions, thus achieving long unattended processing. Derived from the benefits of more than five. Such as: reducing the labor intensity of the workers, save the labor force (one can look after more than one machine), a decrease of tooling, shorten Trial Production of a new product cycle and the production cycle, the market demand for quick response, and so on. These advantages are our predecessors did not expect, is a very major breakthrough. In addition, CNC machine tools or the FMC (Flexible Manufacturing Cell), FMS (flexible manufacturing system) and CIMS (Computer Integrated Manufacturing System), and other enterprises, the basis of information transformation. NC manufacturing automation technology has become the core technology and basic technology. The macro view of the necessity .From a macro perspective, the military industrial developed countries, the machinery industry, in the late 1970s, early 1980s, has begun a large-scale application of CNC machine tools. Its essence is the use of information technology on the traditional industries (including the military, the Machinery Industry) for technological transformation. In addition to the manufacturing process used in CNC machine t ools, FMC, FMS, but also included in the product development in the implementation of CAD, CAE, CAM, virtual manufacturing and production management in the implementation of the MIS (Management Information System), CIMS, and so on. And the products that they produce an increase in information technology, including artificial intelligence and other content. As the use of information technology to foreign forces, the depth of Machinery Industry (referred to as information technology), and ultimately makes their products in the international military and civilian products on the market competitiveness of much stronger. And we in the information technology to transform traditional industries than about 20 years behind developed countries. Such as possession of machine tools in China, the proportion of CNC machine tools (CNC rate) in 1995 to only 1.9 percent, while Japan in 1994 reached 20.8 percent, every year a large number of imports of mechanical and electrical products. This also explains the macro CNC transformation of the need. Third, CNC machine tools and production lines of the transformation of the market CNC transformation of the market .My current machine total more than 380 million units, of which only the total number of CNC machine tool 113,400 Taiwan, or that China's CNC rate of less than 3 percent. Over the past 10 years, China's annual output of about 0.6 CNC machine tools to 0.8 million units, an annual output value of about 1.8 billion yuan. CNC machine tools annual rate of 6 per cent. China's machine to ol easements over age 10 account for more than 60% below the 10 machines, automatic / semi-automatic machine less than 20 per cent, FMC / FMS, such as a handful more automated production line (the United States and Japan automatic and semi-automatic machine, 60 percent above). This shows that we the majority of manufacturing industries and enterprises of the production, processing equipment is the great majority of traditional machine tools, and more than half of military age is over 10 years old machine. Processing equipment used by the prevalence of poor quality products, less variety, low-grade, high cost, supply a long period, in view of the international and domestic markets, lack of competitiveness, and a direct impact on a company's products, markets, efficiency and impact The survival and development of enterprises. Therefore, we must vigorously raise the rate of CNC machine tools. Import equipment and production lines of the transformation of NC market .Since China's reform and opening up, many foreign enterprises from the introduction of technology, equipment and production lines for technological transformation. According to incomplete statistics, from 1979 to 1988 10, the introduction of technological transformation projects are 18,446, about 16.58 billion US dollars. These projects, the majority of projects in China's economic construction play a due role. Some, however, the introduction of projects due to various reasons, not equipment or normal operation of the production line, and e