,机电技术专业英语,2,Lesson Seven,Text,Mechanical design is the application of science and technology to devise or improved products for the purpose of satisfying human needs. It is a vast field of engineering technology which not only concerns itself with the original conception of the product in terms of its size, shape and construction details, but also considers the various factors involved in the manufacture, marketing and use of the product. People who perform the various functions of mechanical design are typically called designers, or design engineers. Mechanical design is basically a creative activity. However, in addition to being innovative, a design engineer must also have a solid background in the areas of mechanical drawing, kinematics, dynamics, materials engineering, strength of materials and manufacturing processes.,Introduction to Mechanical Design,As stated previously, the purpose of mechanical design is to produce a product which will serve a need for man. Inventions, discoveries and scientific knowledge by themselves do not necessarily benefit people; only if they are incorporated into a designed product will a benefit be derived. It should be recognized, therefore, that a human need must be identified before a particular product is designed. Mechanical design should be considered to be an opportunity to use innovative talents to envision a design of a product, to analyze the system and then make sound judgments on how the product is to be manufactured. It is important to understand the fundamentals of engineering rather than memorize mere facts and equations. There are no facts or equations which alone can be used to provide all the correct decisions required to produce a good design. On the other hand, any calculations made must be done with the utmost care and precision. For example, if a decimal point is misplaced, an otherwise acceptable design may not function.,Lesson Seven,4,New Words and Expressions,Lesson Seven,5,Lesson Seven,6,Notes,1. thrust aside 推开，把搁置一边 2. for the sake of 为了，为起见 3. manufacturing cycle 制造周期,Lesson Seven,参考译文,机械设计是一门通过设计新产品或者改进老产品，以满足人类需要的应用技术科学。它涉及工程技术的各个领域，它不仅研究传统理念上的产品的尺寸、形状和详细结构的基本构思，还要研究产品在制造、销售和使用等方面的问题。 进行各种机械设计的工作人员通常被称为设计人员或设计工程师。机械设计是一门创造性的工作，设计工程师不仅在工作上要有创新性，还必须在机械制图、 运动学、动力学、工程材料、材料力学和机械制造工艺等方面具有深厚的基础知识。,机械设计概论,Lesson Seven,Lesson Seven,如前面所述，机械设计的目的是生产满足人类需求的产品。发明和科学知识本身不一定能给人类带来益处，只有他们被用在产品上才能产生效益。因而，应该认识到在一个特定产品进行设计之前，必须先确定人们是否需要这种产品。 应当把机械设计看成设计人员运用自身才智进行产品设计，系统设计和制定产品的制造工艺的一个良机。掌握工程知识要比熟记一些数据和公式更为重要。仅仅使用数据和公式是不足以在一个好的设计中做出所需的正确决定的。另一方面，应该认真精确地进行所有运算。例如，即将一个小数点的位置放错，也会使正确的设计变成错误的。,谢谢观赏,www.sciencep.com,Thank You !,