机电技术专业英语 教学课件 作者 徐起贺 张庆良pata a lesson Nine.pptVIP

* 机电技术专业英语 Lesson Nine Text However simple, any machine is a combination of individual components generally referred to as machine elements or parts. Thus, if a machine is completely dismantled, a collection of simple parts remains such as nuts, bolts, springs, gears, cams and shafts—the building block of all machinery1. A machine element is, therefore, a single unit designed to perform a specific function and capable of combining with other elements. Sometimes certain elements are associated in pairs, such as nuts and bolts or keys and shafts. In other instances, a group of elements is combined to form a subassembly, such as bearings, couplings, and clutches. The most common example of machine elements is a gear, which, fundamentally, is a combination of the wheel and the lever to form a toothed wheel. The rotation of this gear on a hub or shaft drives other gears that may rotate faster or slower, depending upon the number of teeth on the basic wheels2. Machine Elements New Words and Expressions Lesson Nine Lesson Nine Lesson Nine Lesson Nine Notes Lesson Nine 1. Thus, if a machine is completely dismantled, a collection of simple parts remains such as nuts, bolts, springs gears, cams and shafts—the building block of all machinery. 因此，如果把机床完全拆开，就可以得到像螺母、螺栓、弹簧、齿轮、凸轮及轴等简单零件——所有机器的标准元件。 2. The most common example of a machine is a gear, which, fundamentally, is a combination of the wheel and the lever to form a toothed wheel. The rotation of this gear on a hub or shaft drives other gears that may rotate faster or slower depending upon the number of teeth on the basic wheels. 机器零件中最常见的是齿轮，它实际上是由轮子和杆组成的带有齿的轮子。在轴套或轴上旋转的齿轮驱动其他齿轮作加速还是减速运动取决于主动齿轮的齿数。 Which 引导非限定性定语从句，修饰gear，不定式短语to form a toothed wheel作结果状语。分词短语depending upon作原因状语。 3. The supporting structure may be assembled with bolts or rivets or by welding. 支撑结构可由螺栓或铆钉或通过焊接固定在一起。 be assembled with 由…安装，by welding作方式状语。 Lesson Nine Lesson Nine 参考译文 无论何种简单的机床，都是由单一的元件即机械零件或部件组