英语翻译2.1.1 Reciprocating EngineExcept for the wanked rotary e

英语翻译
2.1.1 Reciprocating Engine
Except for the wanked rotary engine ,all production automotive engines are the reciprocating ,or piston ,design.Reciprocating means “up and down”or“back and forth”.It is this up-and-down action of a piston in a cylinder that gives the reciprocating engine it's name .Almost all engines of this type are built upon a cylinder block ,or engine block.The block is an iron or aluminum casting that contains the engine cylinders .The top of the block is covered with the cylinder head ,which forms the combustion chambers .The bottom of the block is covered with an oil pan ,or oil sump .A major exception to this type of engine construction is the air-cooled engines used by Porsche ,Chevrolet (Corvair) ,and some other automobile manufacturers in years past .
Power is produced by the inline motion of a piston in a cylinder .However ,this linear motion must be changed to rotating motion to turn the wheels of a car or truck .The piston is attached to the top of a connecting rod by a pin ,called a piston pin or wristpin(Figure 2-2) .The bottom of the connecting rod is attached to the crankshaft .The connecting rod transmits the up-and-down motion of the piston to the crankshaft ,which changes it to rotating motion .The connecting rod is mounted on the crankshaft with large bearings called rod bearings .Similar bearings ,called main bearings ,are used to mount the crankshaft in the block (Figure 2-2) .

除的wanked转子发动机,所有生产汽车的发动机是往复,活塞,设计.往复运动装置“向上和向下”或者“来回”.它是这样的向上和向下运动的活塞在一个给出了往复式发动机的缸,它的名字.几乎所有这种类型的发动机的气缸体,或引擎块是建立在.块是一个包含发动机气缸的铁或铝铸造.覆盖块的顶部与气缸盖中,形成的燃烧室.块的底部的覆盖用的油盘,或油槽.这种类型的发动机制造一个主要的例外是保时捷,雪佛兰（科维尔）,以及其他一些汽车制造商在过去的几年中使用的空气冷却发动机.功率是由内嵌在气缸内的活塞运动.然而,这种直线运动,必须改变的旋转运动来转动车轮的汽车或卡车.该活塞被连接到由销的连接杆的顶部,称为活塞销与活塞销（图2-2）.连接杆的底部安装到曲轴.连杆发送的向上和向下运动的活塞的曲轴,从而改变它的旋转运动.连接杆被安装在曲轴上的被称为连杆轴承的大型轴承.称为主轴承,类似的轴承,在块中（图2-2）,用于安装在曲轴.