機械數(shù)控外文翻譯---普通車床的主軸箱

1、<p>　　Headstock of Engine Lathe</p><p>　　The headstock assembly is permanently fastened to the left end of the lathe. It contains the headstock spindle, which is rotated by gears or by a combination of

2、gear and pulleys. The spindle holds the attachments which, in turn, hold and turn the workpiece. Spindles come in several quality ratings and are supported in headstocks by three to five bearings. Since the accuracy of t

3、he work done on a lathe depends on the axis of rotation of the spindle holding the workpiece, the spindle and all its a</p><p>　　A hold extends through the spindle itself. The front end of this hole is taper

4、ed for holding tools having a tapered shank. A taper sleeve (a hollow-round part) fits into the taper spindle hole, when holding a headstock, or live center. The headstock center is called a live center because it turns

5、with the work. The center is a tapered metal part with a pointed end. It is used to support the end of a workpiece as it is being turned. All lathe center point have a 60-degree(°) included angle.</p><p&g

6、t;　　Three common types of spindle noses are used to hold attachments on the spindle.</p><p>　　1. The threaded spindle nose has been used on lathes longer than any of the other types. Attachments to be mounte

7、d are screwed onto the spindle until they fit firmly against the spindle flange. The major disadvantage of the threaded spindle nose is that turning cannot be done in the reverse position (with the spindle turning clockw

8、ise). This is Because certain attachments, a chuck for example, would come loose.</p><p>　　2. The cam lock spindle nose has a very short taper which fits into a tapered recess in the back of a faceplate or c

9、huck. A series of cam lock studs projects from the back of the faceplate or chuck. These cam lock studs fit into the hole in the spindle nose. They are locked into position by turning a series of cams.</p><p&g

10、t;　　3. The long (steep) taper key drive spindle nose has a long taper with a key attached and an internal threaded collar. The faceplate or chuck must have an equal taper and keyway plus an external thread. This positive

11、 lock-type of spindle is most popular on medionum-size lathes. It permits cutting with the spindle turning in either direction.</p><p>　　Power for driving the spindle is provided by an electric motor. There

12、are four common ways of transmitting the power form the electric motor to the spindle. These include:</p><p>　　Flat belt drive. On most belt-driven lathes, direct drive power is delivered through belts to a

13、step pulley attached to the spindle. The spindle speed is changed by moving the belt to different positions on the step pulley. To obtain slower speeds and more powder, back gears are used.</p><p>　　To under

14、stand how the back gears operate, study Fig, 2-3 Notice that gear F is fastened securely to the spindle. This gear is often called a bull gear. The small end of the step pulley gas a small gear attached to it called a pi

15、nion gear. This gear (E) always turns when the pulley turns. The step pulley and pinion gear are connected with the bull gear by a sliding pin called the bull-gear lock-pir. At the back of the headstock are two gears mou

16、nted on the same shaft. They are spaced to line up o</p><p>　　At the left end of the headstock assembly is a feed reverse lever. It is used for reversing, the direction or movement of the lead screw. This le

17、ver can be moved to three positions. When it is in the upper position with the automatic feed engaged, the carriage will move to-ward the headstock (to the left) and the cross-feed will move in. When in the center positi

18、on, the gears are out of mesh and the lead screw will not move. When in the lower position with the automatic feed engaged, the carriag</p><p>　　V-belt drive. A V-shaped groove is cut around the circumferenc

19、e of each pulley, and a V belt fits accurately into this groove. The V belt does not touch the bottom of the pulley. This type of drive has a back gear arrangement similar to that used on flat belt machines.</p>&

20、lt;p>　　Variable-speed driver. In this arrangement it is possible to change the speed between the driver and driven pulleys without stopping the lathe. In fact, the speed must be changed only when the machine is runnin

21、g. The driving pulley of a variable-speed drive is made with parts having V-shaped sides. One side of the pulley may be opened or spread apart from the other side. As it spreads apart, the belt moves inward toward the sm

22、aller diameter, producing a slower speed on the driven pulley. As the </p><p>　　4. Geared head. This headstock contains gears and changing mechanisms for obtaining many different spindle speeds. The speed in

23、dex plate attached to the headstock will help the operator select the required speed. Two or three levers or knobs must be moved to adjust the speed.</p><p><b>　　普通車床的主軸箱</b></p><p>

24、　　主軸箱組件緊固在車床左端。它由主軸箱主軸組成，經(jīng)齒輪或齒輪組和皮帶輪使主軸旋轉(zhuǎn)。主軸有可裝夾并轉(zhuǎn)動工件的附件。主軸有多級轉(zhuǎn)速。主軸箱由3~5個支座支承。由于車床上工件的加工精度取決于夾持工件的主軸旋轉(zhuǎn)軸的精度，故必須十分仔細地制造和安裝主軸及其所有附件。</p><p>　　主軸本身有一個通孔，這個孔的前端是一錐孔，可用來安裝帶錐柄的刀具。安裝主軸箱活頂尖時，用一錐套配入主軸的錐孔內(nèi)。主軸箱頂尖可隨工件旋轉(zhuǎn)，

25、故可稱活頂尖。它是一個帶尖端的錐金屬件。工件旋轉(zhuǎn)時可用來支承工件，所有車床頂尖均為60°角。</p><p>　　在主軸上安裝附件，常使用三種通用的主軸頭：</p><p><b>　　1. 螺紋主軸頭</b></p><p>　　車床上最常用的是螺紋主軸頭。將安裝的附件擰到主軸上，直到與主軸法蘭盤緊密相配。螺紋主軸頭的主要缺點是不能

26、進行反向車削，因有些附件（例如卡盤）反向時會松開。</p><p>　　2. 凸輪鎖緊主軸頭</p><p>　　凸輪鎖緊主軸頭有一個非常短的錐體，她可以配入花盤或卡盤背面的錐槽內(nèi)。從花盤或卡盤背面伸出許多凸輪鎖緊短軸，這些短軸可配入主軸頭的孔內(nèi)。轉(zhuǎn)動這些凸輪就可將它們鎖緊在規(guī)定位置。</p><p>　　3. 長錐鍵傳動主軸頭</p><p&g

27、t;　　它有一個很長的錐體。錐體帶一附加鍵和一內(nèi)螺紋套爪?；ūP或卡盤必須與其錐度相同并帶有外螺紋鍵槽。這種正向鎖緊型主軸在中型車床中最為普遍。它允許主軸在正向或反向旋轉(zhuǎn)時均能切削。</p><p>　　驅(qū)動主軸的動力由一電動機供給，從電動機將動力傳遞給主軸有四種常用的方法：</p><p><b>　　平皮帶傳動</b></p><p>　　在

28、大多數(shù)皮帶傳動的車床中，直接驅(qū)動動力通過皮帶傳遞給附在主軸的塔輪上。把皮帶移動到塔輪的不同位置，就可改變主軸速度。為獲得較低速和較大動力，可使用背輪。</p><p>　　背輪的工作原理見圖2-3。齒輪F緊固在主軸上，常稱齒輪F為大齒輪。塔輪的小端有一小齒輪E。塔輪轉(zhuǎn)動時，齒輪E總是轉(zhuǎn)的。塔輪的小齒輪通過一個稱作大齒輪鎖緊銷的滑動銷與大齒輪相連。床頭箱背面有兩個安裝在同一軸上的齒輪。它們間隔排開，與大齒輪F和小齒

29、輪E相嚙合。這些齒輪叫背輪。為了使背輪嚙合，要推出大齒輪銷子（此銷子推出時，塔輪和小齒輪轉(zhuǎn)動而主軸不轉(zhuǎn)）。向前推背輪手柄，使背輪與大齒輪F和小齒輪E相嚙合。接通電源時，決不能用手轉(zhuǎn)動塔輪使其嚙合。嚙合時，動力直接由背輪傳遞給大齒輪F和主軸。</p><p>　　床頭箱左端有一反向進給桿。它用于絲杠的反向運動。此桿有三個位置。在上自動進給位置時，床鞍將向床頭箱方向（即向左）移動，橫進給向外運動。</p>

30、<p><b>　　三角皮帶傳動</b></p><p>　　每個皮帶輪的圓周上都開有一個V型槽。三角皮帶將精確地嵌入槽內(nèi)。三角皮帶不能碰到皮帶輪的底部。這種傳動方式也有一個與平皮帶傳動相似的背輪裝置。</p><p><b>　　無級變速傳動</b></p><p>　　這種裝置不用停車就可以改變主動輪和從

31、動輪間的速度。實際上只有在機床運行時才需變速。無級變速傳動的傳動皮帶輪由二個V型側(cè)面的半輪組成。皮帶輪的一側(cè)可以是打開的，即與另一側(cè)脫開。在脫開時，皮帶就向里移動到較小直徑，使從動輪產(chǎn)生較低速度。當皮帶輪兩側(cè)合在一起時，就迫使皮帶輪向外移動到較大直徑，使從動輪速度增大。可以用手動或液壓進行變速。采用液壓方式時，床頭箱頂部的控制盤可使液壓系統(tǒng)精確動作。電動機停止時，不要轉(zhuǎn)此控制盤。直接傳動的轉(zhuǎn)速范圍為300~1600轉(zhuǎn)/分。</p&