【正文】 that is ,a righthand driver goes with a righthand driven. In the design of crossedhelical gears, the minimum sliding velocity is obtained when the helix angle are equal. However, when the helix angle are not equal, the gear with the larger helix angle should be used as the driver if both gears have the same hand.Worm gears are similar to crossed helical gears. The pinion or worm has a small number of teeth, usually one to four, and since they pletely wrap around the pitch cylinder they are called threads. Its mating gear is called a worm gear, which is not a true helical gear. A worm and worm gear are used to provide a high angularvelocity reduction between nonintersecting shafts which are usually at right angle. The worm gear is not a helical gear because its face is made concave to fit the curvature of the worm in order to provide line contact instead of point contact. However, a disadvantage of worm gearing is the high sliding velocities across the teeth, the same as with crossed helical gears.Worm gearing are either single or double enveloping. A singleenveloping gearing is one in which the gear wraps around or partially encloses the worm.. A gearing in which each element partially encloses the other is, of course, a doubleenveloping worm gearing. The important difference between the two is that area contact exists between the teeth of doubleenveloping gears while only line contact between those of singleenveloping gears. The worm and worm gear of a set have the same hand of helix as for crossed helical gears, but the helix angles are usually quite different. The helix angle on the worm is generally quite large, and that on the gear very small. Because of this, it is usual to specify the lead angle on the worm, which is the plement of the worm helix angle, and the helix angle on the gear。 GEAR AND SHAFT INTRODUCTIONAbstract: The important position of the wheel gear and shaft can39。這些磁極板之間有磁粉混合物潤(rùn)滑。該內(nèi)軸件，在它的周邊加工了數(shù)個(gè)平面。這些離合器通常用彈簧加載，以使得在達(dá)到預(yù)定的力矩時(shí)釋放。雖然強(qiáng)制離合器不像摩擦接觸離合器用的那么廣泛，但它們確實(shí)有很重要的運(yùn)用。各種強(qiáng)制接觸離合器之間最大的區(qū)別與夾爪的設(shè)計(jì)有關(guān)。各種各樣的離合器和制動(dòng)器可作如下分類(lèi)：1． 輪緣式內(nèi)膨脹制凍塊；2． 輪緣式外接觸制動(dòng)塊；3． 條帶式；4． 盤(pán)型或軸向式；5． 圓錐型；6． 混合式。這是一個(gè)靜力學(xué)問(wèn)題。簡(jiǎn)化摩擦離合器或制動(dòng)器的動(dòng)力學(xué)表達(dá)式中，各自以角速度w1和w2運(yùn)動(dòng)的兩個(gè)轉(zhuǎn)動(dòng)慣量I1和I2，在制動(dòng)器情況下其中之一可能是零，由于接上離合器或制動(dòng)器而最終要導(dǎo)致同樣的速度。這樣，它是一個(gè)檢驗(yàn)已經(jīng)設(shè)計(jì)好了的軸的或者發(fā)現(xiàn)具體軸在運(yùn)轉(zhuǎn)中發(fā)生損壞原因的好方法。但決不意味著設(shè)計(jì)者要保證；它們是安全的，軸幾乎總是要進(jìn)行計(jì)算的，知道它們是處在可以接受的允許的極限以?xún)?nèi)。心軸也是軸，既可以旋轉(zhuǎn)也可以靜止的軸，但不承受扭轉(zhuǎn)載荷。在軸上安裝像齒輪，皮帶輪，飛輪，曲柄，鏈輪和其他動(dòng)力傳遞零件。這樣的齒輪機(jī)構(gòu)叫做準(zhǔn)雙曲面齒輪機(jī)構(gòu)，因?yàn)樗鼈兊墓?jié)面是雙曲回轉(zhuǎn)面。直齒錐齒輪易于設(shè)計(jì)且制造簡(jiǎn)單，如果他們安裝的精密而確定，在運(yùn)轉(zhuǎn)中會(huì)產(chǎn)生良好效果。僅就滾齒而言就可達(dá)一級(jí)精度。蝸桿上的齒斜角度通常很大，而蝸輪上的則極小，因此習(xí)慣常規(guī)定蝸桿的導(dǎo)角，那就是蝸桿齒斜角的余角；也規(guī)定了蝸輪上的齒斜角，該兩角之和就等于90度的軸線交角。單包圍機(jī)構(gòu)就是蝸輪包裹著蝸桿的一種機(jī)構(gòu)。蝸桿和蝸輪通常是用于向垂直相交軸之間的傳動(dòng)提供大的角速度減速比。然而當(dāng)該齒的斜角不相等時(shí)，如果兩個(gè)齒輪具有相同齒向的話(huà)，大斜角齒輪應(yīng)用作主動(dòng)齒輪。交錯(cuò)軸斜齒輪與斜齒輪之間在被安裝后互相捏合之前是沒(méi)有任何區(qū)別的。當(dāng)兩個(gè)或更多個(gè)單向齒斜齒輪被在同一軸上時(shí)，齒輪的齒向應(yīng)作選擇，以便產(chǎn)生最小的軸向推力。斜齒輪使軸的軸承承受徑向和軸向力。斜齒輪輪齒的初始接觸是一點(diǎn)，當(dāng)齒進(jìn)入更多的嚙合時(shí)，它就變成線。齒的形狀是一濺開(kāi)線螺旋面。而在錐齒輪的情況中各回轉(zhuǎn)軸線互相不平行。所以我們對(duì)齒輪和軸的了解和認(rèn)識(shí)必須是多層次多方位的。但有些特殊情況，如高速主軸、托盤(pán)自動(dòng)交換裝置的制作與安裝過(guò)于費(fèi)工、費(fèi)錢(qián)，往往改造成本提高2～3倍，與購(gòu)置新機(jī)床相比，只能節(jié)省投資50％左右。、數(shù)控化改造的內(nèi)容機(jī)床與生產(chǎn)線的數(shù)控化改造主要內(nèi)容有以下幾點(diǎn)：其一是恢復(fù)原功能，對(duì)機(jī)床、生產(chǎn)線存在的故障部分進(jìn)行診斷并恢復(fù)；其二是NC化，在普通機(jī)床上加數(shù)顯裝置，或加數(shù)控系統(tǒng)，改造成NC機(jī)床、CNC機(jī)床；其三是翻新，為提高精度、效率和自動(dòng)化程度，對(duì)機(jī)械、電氣部分進(jìn)行翻新，對(duì)機(jī)械部分重新裝配加工，恢復(fù)原精度；對(duì)其不滿(mǎn)足生產(chǎn)要求的CNC系統(tǒng)以最新CNC進(jìn)行更新；其四是技術(shù)更新或技術(shù)創(chuàng)新，為提高性能或檔次，或?yàn)榱耸褂眯鹿に?、新技術(shù)，在原有基礎(chǔ)上進(jìn)行較大規(guī)模的技術(shù)更新或技術(shù)創(chuàng)新，較大幅度地提高水平和檔次的更新改造。從事再生業(yè)的著名公司有：Bertsche工程公司、ayton機(jī)床公司、DevliegBullavd（得寶）服務(wù)集團(tuán)、US設(shè)備公司等。由于機(jī)床以及技術(shù)的不斷進(jìn)步，機(jī)床改造是個(gè)永恒的課題。這些不能使用的設(shè)備、生產(chǎn)線是個(gè)包袱，也是一批很大的存量資產(chǎn)，修好了就是財(cái)富。這些項(xiàng)目中，大部分項(xiàng)目為我國(guó)的經(jīng)濟(jì)建設(shè)發(fā)揮了應(yīng)有的作用。用這種裝備加工出來(lái)的產(chǎn)品普遍存在質(zhì)量差、品種少、檔次低、成本高、供貨期長(zhǎng)，從而在國(guó)際、國(guó)內(nèi)市場(chǎng)上缺乏競(jìng)爭(zhēng)力，直接影響一個(gè)企業(yè)的產(chǎn)品、市場(chǎng)、效益，影響企業(yè)的生存和發(fā)展。近10年來(lái)，～，年產(chǎn)值約為18億元。而我們?cè)谛畔⒓夹g(shù)改造傳統(tǒng)產(chǎn)業(yè)方面比發(fā)達(dá)國(guó)家約落后20年。其本質(zhì)是，采用信息技術(shù)對(duì)傳統(tǒng)產(chǎn)業(yè)（包括軍、民機(jī)械工業(yè)）進(jìn)行技術(shù)改造。以上這些優(yōu)越性是前人想象不到的，是一個(gè)極為重大的突破。 可實(shí)現(xiàn)多工序的集中，減少零件 在機(jī)床間的頻繁搬運(yùn)。 可以實(shí)現(xiàn)加工的自動(dòng)化，而且是柔性自動(dòng)化，從而效率可比傳統(tǒng)機(jī)床提高3～7倍。 Fourth, the technology updates or technical innovation, to enhance performance or grades, or for the use of new technology, new technologies, based on the original technology for largescale update or technological innovation, and more significantly raise the level, and grades of upgrading. , NC transformation of the gifted missing reduce the amount of investment, shorter delivery time Compared with the purchase of new machine, the general can save 60% to 80% of the costs and transforming lowcost. Especially for large, special machine tools particularly obvious. General transformation of largescale machine, spent only the cost of the new machine purchase 1 / 3, short delivery time. But some special circumstances, such as highspeed spindle, automatic tray switching systems and the production of the installation costs too costly and often raise the cost of 2 to 3 times pared with the purchase of new machine, only about 50 percent of savings investment. stable and reliable mechanical properties, structure limitedBy the use of bed, column, and other basic items are heavy and solid casting ponents, rather than kind of welding ponents of the machine after the highperformance, quality, and can continue to use the new equipment。 because some high energy consumption, low pass rate products incur losses, but some have introduced a longer time, and the need for technological upgrading. Some of the causes of the equipment did not create wealth, but consumption of wealth. These can not use the equipment, production lines is a burden, but also a number of significant assets in stock, wealth is repaired. As long as identifying the main technical difficulties, and solve key technical problems, we can minimize the investment and make the most of their assets in stock, gain the greatest economic and social benefits. This is a great transformation of the market. Fourth, NC transformation of the content and gifted missing , the rise of foreign trade reform In the United States, Japan and Germany and other developed countries, and their machine transform ation as new economic growth sector, the business scene, is in a golden age. The machine, as well as technology continues to progress, is a machine of the eternal issue. China39。s products, markets, efficiency and impact The survival and development of enterprises. Therefore, we must vigorously rais