【導讀】球磨機在建材行業(yè)應用廣泛，是目前工業(yè)上廣泛使用的細磨機械。末各種硬度的物料，在礦場和發(fā)電廠均有應用。用，而且在冶金、選礦、化工、電力等工業(yè)中也廣泛采用.承方式相比具有很大的優(yōu)勢。軸承襯采用巴氏合金，引起具有良好的摩擦相容性、設備的要求，因此在生產(chǎn)中已被廣泛使用。關于滑履支承，國外早以在磨機上采用。我國江南水泥廠濕法生料磨機已在進料。由于磨機的大型化發(fā)展，其軸承負荷也俞來俞大，另外烘干兼粉。球磨機大型化后,首先不能滿足中空軸的通風面積(尤其是對于帶烘干倉的。球磨機),其次就是傳統(tǒng)的進出料螺旋筒不能滿足暢通地大量喂料和卸料的要求。

　　

【正文】 of the work piece. Consequently, more lathes of various types are used in manufacturing than any other machine tool. The essential ponents of a lathe are the bed, headstock assembly, tailstock assembly, and the leads crew and feed rod. The bed is the backbone of a lathe. It usually is made of well normalized or aged gray or nodular cast iron and provides s heavy, rigid frame on which all the other basic ponents are mounted. Two sets of parallel, longitudinal ways, inner and outer, are contained on the bed, usually on the upper side. Some makers use an inverted Vshape for all four ways, whereas others utilize one inverted V and one flat way in one or both sets, They are precisionmachined to assure accuracy of alignment. On most modern lathes the way are surfacehardened to resist wear and abrasion, but precaution should be taken in operating a lathe to assure that the ways are not damaged. Any inaccuracy in them usually means that the accuracy of the entire lathe is destroyed. The headstock is mounted in a foxed position on the inner ways, usually at the left end of the bed. It provides a powered means of rotating the word at various speeds. Essentially, it consists of a hollow spindle, mounted in accurate bearings, and a set of transmission gearssimilar to a truck transmission—through which the spindle can be rotated at a number of speeds. Most lathes provide from 8 to 18 speeds, usually in a geometric ratio, and on modern lathes all the speeds can be obtained merely by moving from two to four levers. An increasing trend is to provide a continuously variable speed 洛陽理工學院畢業(yè)設計（論文） 31 range through electrical or mechanical drives. Because the accuracy of a lathe is greatly dependent on the spindle, it is of heavy construction and mounted in heavy bearings, usually preloaded tapered roller or ball types. The spindle has a hole extending through its length, through which long bar stock can be fed. The size of maximum size of bar stock that can be machined when the material must be fed through spindle. The tailstock assembly consists, essentially, of three parts. A lower casting fits on the inner ways of the bed and can slide longitudinally thereon, with a means for clamping the entire assembly in any desired location, An upper casting fits on the lower one and can be moved transversely upon it, on some type of keyed ways, to permit aligning the assembly is the tailstock quill. This is a hollow steel cylinder, usually about 51 to 76mm(2to 3 inches) in diameter, that can be moved several inches longitudinally in and out of the upper casting by means of a hand wheel and screw. The size of a lathe is designated by two dimensions. The first is known as the swing. This is the maximum diameter of work that can be rotated on a lathe. It is approximately twice the distance between the line connecting the lathe centers and the nearest point on the ways, The second size dimension is the maximum distance between centers. The swing thus indicates the maximum work piece diameter that can be turned in the lathe, while the distance between centers indicates the maximum length of work piece that can be mounted between centers. Engine lathes are the type most frequently used in manufacturing. They are heavyduty machine tools with all the ponents described previously and have power drive for all tool movements except on the pound rest. They monly range in size from 305 to 610 mm(12 to 24 inches)swing and from 610 to 1219 mm(24 to 48 inches) center distances, but swings up to 1270 mm(50 inches) and center distances up to 3658mm(12 feet) are not unmon. Most have chip pans and a builtin coolant circulating system. Smaller engine latheswith swings usually not over 330 mm (13 inches) –also are available in 洛陽理工學院畢業(yè)設計（論文） 32 bench type, designed for the bed to be mounted on a bench on a bench or cabi. Although engine lathes are versatile and very useful, because of the time required for changing and setting tools and for making measurements on the work piece, thy are not suitable for quantity production. Often the actual chipproduction tine is less than 30% of the total cycle time. In addition, a skilled machinist is required for all the operations, and such persons are costly and often in short supply. However, much of the operator’s time is consumed by simple, repetitious adjustments and in watching chips being made. Consequently, to reduce or eliminate the amount of skilled labor that is required, turret lathes, screw machines, and other types of semiautomatic and automatic lathes have been highly developed and are widely used in manufacturing. 2 Turning The engine lathe, one of the oldest metal removal machines, has a number of useful and highly desirable attributes. Today these lathes are used primarily in small shops where smaller quantities rather than large production runs are encountered. The engine lathe has been replaced in today’s production shops by a wide variety of automatic lathes such as automatic of singlepoint tooling for maximum metal removal, and the use of form tools for finish on a par with the fastest processing equipment on the scene today. Tolerances for the engine lathe depend primarily on the skill of the operator. The design engineer must be careful in using tolerances of an experimental part that has been produced on the engine lathe by a skilled operator. In redesigning an experimental part for production, economical tolerances should be used. Turret Lathes Production machining equipment must be evaluated now, more than ever before, this criterion for establishing the production qualification of a specific method, the turret lathe merits a high rating. 洛陽理工學院畢業(yè)設計（論文） 33 In designing for low quantities such as 100 or 200 parts, it is most economical to use the turret lathe. In achieving the opt