基于UG的商用車(chē)變速器的三維設(shè)計(jì)及仿真建模（三維圖紙+運(yùn)動(dòng)仿真）

基于UG的商用車(chē)變速器的三維設(shè)計(jì)及仿真建模（三維圖紙+運(yùn)動(dòng)仿真）,基于,ug,商用,變速器,三維設(shè)計(jì),仿真,建模,三維,圖紙,運(yùn)動(dòng) Mechanical Engineering English Lesson 1 Modern Manufacturing Engineering A What Is Manufacturing Maybe you ve never thought about it before but it is all around you It affects every part of your life What is it In this case it is manufacturing Actually manufacturing is not all around you But manufactured products are Look around you right now Name some things you see that were manufactured Chairs notebooks blue jeans books floor tile chalkboards light bulbs pencils eyeglasses nearly everything around you was manufactured The manufacturing industry is important to our society It s essential to our economy An economy is a system for producing and distributing products and services Many people work in manufacturing They help produce products And they buy products with the money they earn The more products people buy the more products are manufactured And this allows more people to work Manufacturing is also important to the economy in another way A piece of material is worth more after it s been changed into a useful product That s added value Value is increased by the manufacturing process B Modern Manufacturing A manufacturing industry needs three basic types of resources Material resources Human resources Capital resources The elements of industry are seven key steps for organizing production Research and Development Production Tooling Production Planning and Control Quality Control Personnel Management Manufacturing Marketing R D is the planning of new products processes or materials and the improvement of old skill R D is such a large important part of the industrial world and requires many people with different talents Production Tooling is the element of industry concerned with these tools The PT obtains the tools machines and equipment needed to make a product The most important parts of Production Planning and Control are routing scheduling dispatching and plan layout The machinery and equipment must be arranged so that production can take place smoothly without wasted time and effort Quality Control can be defined as those activities which prevent defective articles In this way management tries to insure that a product will be acceptable to the buyer Marketing is the process of getting products from those who make them to those who use them and it helps to deliver the right kinds of goods to us in the right form and amount at the time and price Lesson 2 Mechanical Engineering Design Mechanical engineering design is a major segment of engineering it deals with the conception design development refinement and application of machines and mechanical apparatus of all kinds For many students mechanical engineering design is one of their first professional engineering courses Professional engineering is concerned with obtaining solutions to practical problems and the engineers are able to devise better solutions to practical problems The most problems in mechanical engineering design do not have a single right answer Hence modern mechanical engineers are able to produce distinctly better solutions to meet today s needs The engineer must use the best available scientific understanding together with empirical information good judgment When considering a complete machine the engineer invariably finds that the requirements and constraints of the various components are interrelated The modern engineer has become increasingly concerned with the broader considerations of safety ecology and overall quality of life Good designs require trying new ideas and being willing to take a certain amount of risk knowing that if the new idea does not work the existing method can be reinstated Thus a designer must have patience since there is no assurance of success for the time and effort expanded Creating a completely new design generally requires that many old and well established methods be thrust aside This is not easy since many people cling to familiar ideas techniques and attitudes A design engineer should constantly search for ways to improve an existing product and must decide what old proven concepts should be used and what new untried ideas should be incorporated New designs generally have bugs or unforeseen problems which must be worked out before the superior characteristics of the new design can be enjoyed Thus there is a chance for a superior product but only at higher risk It should be emphasized that if a design does not warrant radical new methods such methods should not be applied merely for the sake of change During the beginning stages of design creativity should be allowed to flourish without a great number of constraints Even though many impractical ideas may arise it is usually easy to eliminate them in the early stages of design before firm details are required by manufacturing In this way innovative ideas are not inhibited Quite often more than one design is developed up to the point where they can be compared against each other It is entirely possible that the design which is ultimately accepted will use ideas existing in one of the rejected designs that did not show as much overall promise Another important point which should be recognized is that a design engineer must be able to communicate ideas to other people if they are to be incorporated Communicating the design to others is the final vital step in the design process Undoubtedly many great designs inventions and creative works have been lost to mankind simply because the originators were unable or unwilling to explain their accomplishments to others Presentation is a selling job The engineer when presenting a new solution to administrative management or supervisory persons is attempting to sell or to prove to them that this solution is a better one Unless this can be done successfully the time and effort spent on obtaining the solution have been largely wasted