数控技术应用专业英语教学课件作者刘小芹Lesson+23+Manual+Transmission+in+Automobile幻灯片.ppt

Now please have a glance at paragraph nine in 2 minutes. paragraph Ⅸ: Manual transmissions are lubricated with gear oil12, which must be changed periodically in some cars, although not as frequently as the automatic transmission fluid in a vehicle so equipped. (Some manufacturers specify that changing the gear oil is never necessary except after transmission work or to rectify a leak.) 手动变速器用齿轮油来润滑,在某些汽车里齿轮油必须周期性地更换,但没有自动变速器那么频繁.(一些制造商强调说只有在变速器长时间工作或排除泄露后才有必要更换齿轮油.) Oral English practice : One student ask a question according to the ninth paragraph. Another give an answer. Now please have a glance at paragraph ten in 5 minutes. paragraph Ⅹ: Gear oil has a characteristic aroma, due to the addition of molybdenum disulfide compounds, to lubricate the large degree of sliding friction seen by the teeth due to their helical gear cut, which in turn is done to eliminate the characteristic whine of straight cut spur gears15. Some manufacturers, however, such as Honda16, do not use this additive in their gear lube, specifying regular motor oil until recently, and now their own brand of gear lube which seems to be an enhanced version of motor oil. On motorcycles with wet clutches (clutch is bathed in engine oil), there is usually nothing separating the lower part of the engine from the transmission, so the same oil lubricates both the engine and transmission. 齿轮油有芳香气味，是由于其中添加了二硫化钼。二硫化钼用来减弱斜齿轮啮合时的强烈的滑动摩擦，当斜齿轮啮合平稳时，直齿轮啮合时产生的嘎嘎声就会减小。但是，也有一些制造商如本田直到最近才往他们的齿轮润滑油（特别是普通车用机油）中添加这种添加剂，现在他们的齿轮润滑油似乎是机油的一个升级版。在配备了湿式离合器(离合器浸泡在机油里)的摩托车中，由于变速器与发动机的底部没有被隔开，故他们可以一块被润滑。 Oral English practice : One student ask a question according to the tenth paragraph. Another give an answer. Section Ⅲ： exercises Now it’s time to do the exercises. And please finish them in five minutes. This is the end for lesson 23. The last lesson in Chapter 6 will be given by you yourselves, so please preview lesson 24 carefully in your free time. Lesson 23 Manual Transmission in Automobile 词汇讲解 课文分析 练