英语翻译Lathe and TurningThe Lathe and Its Construction A lathe

英语翻译
Lathe and Turning
The Lathe and Its Construction
A lathe is a machine tool used primarily for producing surfaces of revolution and flat edges.Based on their purpose,construction,number of tools that can simultaneously be mounted,and degree of automation,lathes or,more accurately,lathe-type machine tools can be classified as follows:
(1) Engine lathes
(2) Toolroom lathes
(3) Turret lathes
(4) Vertical turning and boring mills
(5) Automatic lathes
(6) Special-purpose lathes
In spite of that diversity of lathe-type machine tools,they all have common features with respect to construction and principle of operation.These features can best be illustrated by considering the commonly used representative type,the engine lathe.Following is a description of each of the main elements of an engine lathe,which is shown in Fig.11.1.
Lathe bed.The lathe bed is the main frame,involving a horizontal beam on two vertical supporis.It is usually made of grey or nodular cast iron to damp vibrations and is made by casting.It has guideways to allow the carriage to slide easily lengthwise.The height of the lathe bed should be appropriate to enable the technician to do his or her job easily and comfortably.
Headstock.The headstock is fixed at the left hand side of the lathe bed and includes the spindle whose axis is parallel to the guideways (the slide surface of the bed).The spindle is driven through the gearbox,which is housed within the headstock.The function of the gearbox is to provide a number of different spindle speeds (usually 6 up to 18 speeds).Some modern lathes have headstocks with infinitely variable spindle speeds,which employ frictional,electrical,or hydraulic drives.

车（机）床与切削
车床和车床构造
车床主要用于加工旋转表面和圆滑啊边缘,根据车床的用途,结构,可同时切割的刀具数量,自动化程度,车床,更准确的说是车床类机械设备分类如下；
1,普通车床
2,多刀加工机床(不一定对）
3,六角车床
4,立式镗孔车床
5,自动车床
6,专用车床
尽管机床类设备花样繁多,但它们的加工方法和结构有很多共同之处,这些共同特点体现在普通车床上,图11.1对普通车床的各个部分进行了描述,
床身（导轨）；是车床的主要结构,由一个水平梁和两个支撑腿组成,通常是用有抑制震动功能的灰铸铁或球墨铸铁铸成的,上面有导轨,大滑板可在导轨上纵向滑动,床身高度应该适度,以车工能舒适操作为宜,
主轴箱；它位于床身左端,内有主轴,主轴中心线与导轨(床身的滑动表面）平行,主轴由主轴箱内的传动齿轮驱动,齿轮箱的功能是为主轴提供各种不同的速度（一般6---18种速度）,有些新式车床能为主轴提供无级变速,利用摩擦,液压,和电子器件驱动,
主轴都是空心的,前后贯通的,连续加工时棒料可伸进轴内,再有就是主轴的内孔口部是锥形的,可放顶尖用,主轴外表面有螺纹用于装卡盘和花盘等卡具,
尾座；由底座,中部和套管轴组成,底座是铸铁件,可在导轨上滑动,内部有一个锁紧装置,可根据工件长度把尾座锁在导轨的任何位置,中部也是铸铁件,可横向调整,使其轴线与主轴轴线一致,第三部分是套管轴,是经过硬化的钢套,它可在尾座内根据需要调整,伸缩,调整是由手轮螺杆和套管轴内的螺母来完成的,套管轴的开口端是锥形的用于装卡顶尖,麻花钻或镗孔刀杆等工具,套管轴可锁紧在任何伸出的位置上,
大滑板；它的主要功能是横向和纵向进刀,它的形状像H字母,在床身的v型轨道上在主轴箱和尾座之间横向滑行,可用手操作移动,也可由滑板箱内的齿轮装置通过进刀杠(光杠）或进刀丝杠（丝杠）移动,
当车螺纹工件时,滑板箱是由丝杠驱动的,车其他工件时,大滑板都是由光杠驱动的,