機(jī)械類中英文翻譯--凸輪

1、<p><b>　　英文原文</b></p><p><b>　　Cams</b></p><p>　　Various motions can be produced by the action of a cam against a follower.Mamy timing devices are operated by can act

2、ion.The purpose of andy cam is to produce a displacement of its follower;a secondary follower is often .used to produce additional displacement in another location.The most popular type is the plate cam.The cylindrical t

3、ype is used to transmit linear motion to a follower as the cam rotates.Three-dimensional cam are sometimes used;these provide some unusual follower motions,but als</p><p>　　Cam profiles are accurately constr

4、ucted by either praphical or mathematical methods.The transitiom from development drawings to working (shop) drawing can be made in several ways:</p><p>　　1.Make a full-scale template.This is desirable from

5、the manufacturing standpoint,but it will not guarantee accurate cam profiles.</p><p>　　2.Use radial dimensions.This is fairly accurate,but sometimes produces layout problems in the shop.</p><p>

6、　　3.Use coordinate dimensioning.This procedure will ensure accuracy.</p><p>　　In selecring one of these methods,one should consider the function of the cam in terms of desired preciseness.</p><p&g

7、t;　　Because the cam work outline already determined, therefore the cam structural design mainly was determines the curve outline axial thickness and the cam and the drive shaft connection way. When the work load compares

8、 the hour, curve outline axial thickness generally takes for the outline curve biggest radius of vector 1,/10 ～/5; Regarding a stress bigger important situation, must with carry on the design according to the cam contour

9、 surface from the contact intensity.</p><p>　　When determination cam and drive shaft joint way, should synthesize the consideration cam the assembling and dismantling, the adjustment and firmly grades the qu

10、estion. Regarding implementing agency more equipment, between its each execution component movement coordination usually determined by the cycle of motion chart, therefore in assembly cam gear time, the cam contour curve

11、 initial station (pushes regulation starts) the relative position to have according to the cycle of motion chart to car</p><p>　　From structural design: from structure: When design must consider from the gui

12、dance and prevented revolves. From movement rule design: Involves many aspects from the movement rule design the questions, besides consideration rigidity impact and flexible impact, but also should maximum speed vmax wh

13、ich has to each kind of movement rule, maximum acceleration amax and its the influence performs the comparison. 1) vmax bigger, then momentum mv is bigger. If from is suddenly prevented, the oversized m</p><p&

14、gt;　　From structural design: from structure: When design must consider from the guidance and prevented revolves. From movement rule design: The cam gear design basic question 1. cam gears type choice, the definite cam sh

15、ape, with from maintains the high vice- contact from the shape and the movement form and the cam the way 2. from the movement rule design, according to the application situation to from the travelling schedule and the st

16、ate of motion request, determines from the movement rule. 3. cam </p><p>　　Fromstructural design: from structure: When design must consider from the guidance and prevented revolves. From movement rule design

17、: The cam gear design basic question 1. cam gears type choice, the definite cam shape, with from maintains the high vice- contact from the shape and the movement form and the cam the way 2. from the movement rule design,

18、 according to the application situation to fromthe travelling schedule and the movement 1, the cam gear application cam gear is includes the cam the</p><p>　　3rd, the throwout lever movement rule (1) the cam

19、 gear cycle of motion and the basic term terminology push the regulation movement angle: With from pushes the cam corner which the regulation corresponds; Far stops the angle: With from far rests the cam corner which the

20、 regulation corresponds; Return trip movement angle: With cam corner which corresponds from the return trip; Nearly stops the angle: With from nearly rests the cam corner which the regulation corresponds; Cam: Take the c

21、am axle cen</p><p>　　Types of Cams</p><p>　　Plate cams are simple to fabricate.The follower can be moved in various patterns with various rise /fall ratios.Motion should be controlled to avoid a

22、brupt changes in force transmitted from the cam to the follower.One should carefully determine horizontal force components,since these present problems designing the follower assembly guide.Critical reactions occur at po

23、ints A and B.These reaction values must be computed.The relative vertical position of point A with respect to B needs to be raised</p><p>　　This type produces reciprocating motion in the follower.Again,dorce

24、s need to be determined and dimensions chosen so as to avoid excessive component sizes.A tapered roller follower is frequently employed ;the groove in the periphery of the cam should be shaped to accommodate the follower

25、.This type of cam is expensive to produce.The cylindrical cam has two outstanding features.One is the fact that the cam is positive actiong.N outside forces (such as gravity or spring action ) are needed to hold t</p&

26、gt;<p>　　A translation cam is illustrated.In the figure shown the cam reciprocates horizontally and the follower moves up and down.A pivoted follower can be used with this type .The translation cam can be made pos

27、itive by providing a guided plate with an inclined slot for the cam;the slot cam then engage a pin or roller on a guided vertical reciprocated follower.With the latter type ,however,a complete force analysis is a critica

28、l phase of the design.</p><p>　　In this type,the cam rotates and the follower (ususlly a roller or pin) is guided by a groove cut into the end face of a cylindrical section .Rotation of the cam provides tran

29、slation of the follower.This type is also positive acting.Production costs for this type of cam are much higher than for a simple plate cam.</p><p>　　A constant –diameter cam is illustrated .This is merely a

30、 circular plate with the camshaft hole eccentrically located.The amount of eccentricity determines the amount of follower displacement.As the cam rotates,the follower reciprocates.This arrangement is sometimes known as a

31、 Scotch yoke mechanism.Follower action is positive ;harmonic motion is produced by this type of arrangement.</p><p>　　Types of Followers</p><p>　　In neneral,the follower is considered to be the

32、part that comes in contact with the cam profile .However,when a seconday follower is used, the motion of the secondary follower is dictated by that of the primary follower.For example ,a roller follower can be reciprocat

33、ed by acting against the edge of a pivoted follower.</p><p>　　The simplest type of follower is the reciprocationg type that merely moves up and down (or in and out ) with the rotation of the cam;the centerl

34、ine can be either collinear with the cam centerline or offset from it .Contact with the cam can be via a point,a knife edge,a suface ,or a roller.A flat-afced reciprocating follower is shown If a point or surface is empl

35、oyed for contact the high normal force can result in abrasion and excessive wear.If the load being transmitted from the cam to the foll</p><p>　　Cam rollers are commercially available in roller sizes ranging

36、 from1/2 in .to 6 in Basic dynamic capacities range from 620 to 60000 ,based on 33.33 rpm and 500hr of minimum life .Correction factors must be used for any other speed or life values.It should be noted that the cam can

37、be lubricated through and oil hole in the end of the shank.Rolling contact with the cam surface minimizes wear problems.Several mounting arrangements are possible with this type of followr .shows the roller follower mo&l

38、t;/p><p><b>　　漢語翻譯:</b></p><p><b>　　凸輪</b></p><p>　　通過凸輪和從動(dòng)件的作用，可得到不同的運(yùn)動(dòng)。許多計(jì)時(shí)裝置由凸輪驅(qū)動(dòng)。使用凸輪的目的是使其從動(dòng)件產(chǎn)生位移，次級從動(dòng)件常用來在另一位置產(chǎn)生附加位移。最常用的凸輪是盤形凸輪。圓柱凸輪用來將其旋轉(zhuǎn)運(yùn)動(dòng)轉(zhuǎn)變?yōu)閺膭?dòng)件的直線運(yùn)動(dòng)。最

39、常用的凸輪是盤形凸輪。圓柱凸輪用來將其放置運(yùn)動(dòng)轉(zhuǎn)變?yōu)閺膭?dòng)件的直線運(yùn)動(dòng)。有時(shí)也用三維凸輪，它們提供一些不建黨的從動(dòng)件運(yùn)動(dòng)，也使從動(dòng)件設(shè)計(jì)難度加大。汽車發(fā)動(dòng)機(jī)上的凸輪軸顯示了盤形凸輪的簡單和重要的應(yīng)用場合，錄音機(jī)上的凸輪組件是更復(fù)雜的應(yīng)用實(shí)例。</p><p>　　凸輪輪廓可用作圖法或數(shù)學(xué)計(jì)算法來精確設(shè)計(jì)，將設(shè)計(jì)圖轉(zhuǎn)換成加工圖可用下面幾種方法：</p><p>　　制造一個(gè)實(shí)尺樣板。這是制造

40、需要，但不能保證精確的凸輪輪廓。</p><p>　　使用徑向尺寸設(shè)計(jì)。這相當(dāng)精確，但在生產(chǎn)時(shí)有時(shí)會(huì)產(chǎn)生排布問題。</p><p>　　用座標(biāo)尺寸設(shè)計(jì)。這種方法能保證精度。</p><p>　　選用這些方法時(shí)，應(yīng)按要求的精度考慮凸輪的作用。</p><p><b>　　凸輪的結(jié)構(gòu)設(shè)計(jì)：</b></p>&l

41、t;p>　　因凸輪的工作輪廓已經(jīng)確定，所以凸輪的結(jié)構(gòu)設(shè)計(jì)主要是確定曲線輪廓的軸向厚度和凸輪與傳動(dòng)軸的連接方式。當(dāng)工作載荷較小時(shí)，曲線輪廓的軸向厚度一般取為輪廓曲線最大矢徑的1/10～1/5；對于受力較大的重要場合，需按凸輪輪廓面與從動(dòng)件間的接觸強(qiáng)度進(jìn)行設(shè)計(jì)。</p><p>　　在確定凸輪與傳動(dòng)軸的聯(lián)接方式時(shí)，應(yīng)綜合考慮凸輪的裝拆、調(diào)整和固定等問題。對于執(zhí)行機(jī)構(gòu)較多的設(shè)備，其各執(zhí)行構(gòu)件之間的運(yùn)動(dòng)協(xié)調(diào)性通常由

42、運(yùn)動(dòng)循環(huán)圖確定，因此在裝配凸輪機(jī)構(gòu)時(shí)，凸輪輪廓曲線起始點(diǎn)（推程開始點(diǎn)）的相對位置需按運(yùn)動(dòng)循環(huán)圖進(jìn)行調(diào)整，以保證各執(zhí)行構(gòu)件能按預(yù)定程序協(xié)調(diào)動(dòng)作。為此，在結(jié)構(gòu)設(shè)計(jì)上要求凸輪能相對于傳動(dòng)軸沿圓周方向進(jìn)行轉(zhuǎn)動(dòng)，并可靠地加以固定。最簡便的方法是采用緊定螺釘固定凸輪，或用緊定螺釘預(yù)固定，待調(diào)整好后再用銷子固定。</p><p><b>　　從動(dòng)件的結(jié)構(gòu)設(shè)計(jì)：</b></p><p&g

43、t;　　直動(dòng)從動(dòng)件的結(jié)構(gòu)：設(shè)計(jì)時(shí)要考慮從動(dòng)件的導(dǎo)向和防止旋轉(zhuǎn)。</p><p>　　從動(dòng)件運(yùn)動(dòng)規(guī)律的設(shè)計(jì):</p><p>　　從動(dòng)件運(yùn)動(dòng)規(guī)律的設(shè)計(jì)涉及許多方面的問題，除考慮剛性沖擊和柔性沖擊外，還應(yīng)對各種運(yùn)動(dòng)規(guī)律所具有的最大速度vmax、最大加速度amax及其影響加以比較。</p><p>　　1)  vmax愈大，則動(dòng)量mv愈大。若從動(dòng)件突然

44、被阻止，過大的動(dòng)量會(huì)導(dǎo)致極大的沖擊力，危及設(shè)備和人身安全。因此，當(dāng)從動(dòng)件質(zhì)量較大時(shí)，為了減小動(dòng)量，應(yīng)選擇vmax值較小的運(yùn)動(dòng)規(guī)律。</p><p>　　2)  amax愈大，慣性力愈大。作用在高副接觸處的應(yīng)力愈大，機(jī)構(gòu)的強(qiáng)度和耐磨性要求也就愈高。對于高速凸輪，為了減小慣性力的危害，應(yīng)選擇amax值較小的運(yùn)動(dòng)規(guī)律。</p><p>　　前述幾種運(yùn)動(dòng)規(guī)律的vmax、amax

45、、沖擊特性及適用場合如下表</p><p>　　對于擺動(dòng)從動(dòng)件凸輪機(jī)構(gòu)，其運(yùn)動(dòng)線圖的橫坐標(biāo)表示凸輪轉(zhuǎn)角，縱坐標(biāo)則分別表示從動(dòng)件的角位移、角速度和角加速度。這類運(yùn)動(dòng)線圖具有的運(yùn)動(dòng)特性與上述相同。</p><p>　　凸輪機(jī)構(gòu)設(shè)計(jì)的基本問題</p><p>　　1. 凸輪機(jī)構(gòu)類型選擇，確定凸輪形狀、從動(dòng)件形狀與運(yùn)動(dòng)形式及凸輪與從動(dòng)件維持高副接觸的方式</p>

46、<p>　　2. 從動(dòng)件運(yùn)動(dòng)規(guī)律設(shè)計(jì)，根據(jù)應(yīng)用場合對從動(dòng)件行程和運(yùn)動(dòng)特性的要求，確定從動(dòng)件運(yùn)動(dòng)規(guī)律。</p><p>　　3. 凸輪機(jī)構(gòu)基本參數(shù)設(shè)計(jì)，確定從動(dòng)件行程、各運(yùn)動(dòng)角、凸輪基圓半徑、偏距、滾子半徑、中心距、從動(dòng)件長度等。</p><p>　　4. 凸輪輪廓曲線設(shè)計(jì)。</p><p>　　5. 凸輪機(jī)構(gòu)承載能力計(jì)算。</p><

47、;p>　　6. 凸輪機(jī)構(gòu)結(jié)構(gòu)設(shè)計(jì)，繪制機(jī)構(gòu)裝配圖和各零件的工作圖。</p><p><b>　　凸輪機(jī)構(gòu)的應(yīng)用</b></p><p>　　凸輪機(jī)構(gòu)是含有凸輪的高副機(jī)構(gòu)，凸輪機(jī)構(gòu)具有結(jié)構(gòu)簡單，可以準(zhǔn)確實(shí)現(xiàn)要求的運(yùn)動(dòng)規(guī)律等優(yōu)點(diǎn)，因而在工業(yè)生產(chǎn)中得到廣泛的應(yīng)用，特別是自動(dòng)機(jī)械和自動(dòng)控制裝置中，得到廣泛的應(yīng)用。</p><p><b&g

48、t;　　凸輪機(jī)構(gòu)的分類</b></p><p>　　按兩活動(dòng)構(gòu)件間的相對運(yùn)動(dòng)特性分類</p><p>　　(1)平面凸輪機(jī)構(gòu)</p><p><b>　　1)盤形凸輪；</b></p><p><b>　　2)移動(dòng)凸輪。 </b></p><p>　　

49、(2)空間凸輪機(jī)構(gòu)</p><p>　　按從動(dòng)件運(yùn)動(dòng)副元素形狀分類</p><p><b>　　(1)尖頂從動(dòng)件；</b></p><p>　　(2)滾子從動(dòng)件；</p><p>　　(3)平底從動(dòng)件。</p><p>　　注：在介紹凸輪機(jī)構(gòu)分類這部分內(nèi)容時(shí)，應(yīng)指出各種凸輪機(jī)構(gòu)的優(yōu)缺點(diǎn)及其適

50、應(yīng)場合，說明各種凸輪機(jī)構(gòu)的內(nèi)在聯(lián)系，為以后的移動(dòng)凸輪及圓柱凸輪輪廓的設(shè)計(jì)打下基礎(chǔ)。</p><p><b>　　推桿的運(yùn)動(dòng)規(guī)律</b></p><p>　　（1）凸輪機(jī)構(gòu)的運(yùn)動(dòng)循環(huán)及基本名詞術(shù)語</p><p>　　推程運(yùn)動(dòng)角：與從動(dòng)件推程相對應(yīng)的凸輪轉(zhuǎn)角；</p><p>　　遠(yuǎn)休止角 ： 與從動(dòng)件遠(yuǎn)休程相對應(yīng)

51、的凸輪轉(zhuǎn)角；</p><p>　　回程運(yùn)動(dòng)角：與從動(dòng)件回程相對應(yīng)的凸輪轉(zhuǎn)角；</p><p>　　近休止角 ： 與從動(dòng)件近休程相對應(yīng)的凸輪轉(zhuǎn)角；</p><p>　　凸輪基圓 ： 以凸輪軸心為圓心,以其輪廓最小向徑 r0 為半徑的圓； 從動(dòng)件行程: 在推程或回程中從動(dòng)件的最大位移,用 h 表示；</p><p>

52、;　　偏 距 : 凸輪回轉(zhuǎn)中心與從動(dòng)件導(dǎo)路間的偏置距離,用 e 表示。</p><p>　　凸輪的類型有以下幾種：</p><p>　　盤形凸輪設(shè)計(jì)簡單，制造容易。切向盤形凸輪，常用來適時(shí)開關(guān)閥門。從動(dòng)件可按不同升降比實(shí)現(xiàn)不同形式的運(yùn)動(dòng)，應(yīng)控制運(yùn)動(dòng)以避免凸輪傳到從動(dòng)件的力發(fā)生突變。設(shè)計(jì)者應(yīng)仔細(xì)分析從動(dòng)件受力的水平力分量，因?yàn)樗鼈儠?huì)使從動(dòng)件的導(dǎo)向出現(xiàn)問題。極限情況出現(xiàn)在A、B點(diǎn)必須計(jì)算這兩點(diǎn)

53、的作用力值。如果B點(diǎn)的值超量，點(diǎn)A相對于B的垂直位置就要升同。B點(diǎn)應(yīng)量靠近凸輪，以減少滾子從動(dòng)件支承彎曲。</p><p>　　圓柱凸輪，它使從動(dòng)件產(chǎn)生往復(fù)運(yùn)動(dòng)。需用分析受力，選擇尺寸，以避免零件尺寸過大。圓柱凸輪經(jīng)常使用錐形滾了從動(dòng)件，并將凸輪表面上的槽適當(dāng)加工以容納從動(dòng)件。這種凸輪制造成本高。圓柱凸輪有兩個(gè)突出特點(diǎn)：一個(gè)特點(diǎn)是：凸輪與從動(dòng)件為幾何鎖合，不需要外力（如重力或彈簧力）將從動(dòng)件貼緊凸輪工作面；第二個(gè)

54、特點(diǎn)是：可在凸輪轉(zhuǎn)幾轉(zhuǎn)中，從動(dòng)件完成一個(gè)完整循環(huán)。比如，可設(shè)計(jì)這樣的凸輪，當(dāng)凸輪轉(zhuǎn)3轉(zhuǎn)（或更多轉(zhuǎn)）時(shí)，從動(dòng)件從左端起始點(diǎn)運(yùn)動(dòng)到右端極限位置，然后凸輪再轉(zhuǎn)2轉(zhuǎn)使從動(dòng)件回到起點(diǎn)。當(dāng)然，還可能有其他設(shè)計(jì)。</p><p>　　凸輪水平往復(fù)運(yùn)動(dòng)，從動(dòng)作一下運(yùn)動(dòng)。擺動(dòng)從動(dòng)件也可用于這種形式。通過帶有斜槽的導(dǎo)板，可使移動(dòng)凸輪與從動(dòng)件實(shí)現(xiàn)幾何鎖合，斜槽與作垂直往復(fù)運(yùn)動(dòng)的從動(dòng)件上的銷或滾子配合。然而，在后一種型式中，完整的力的分

55、析是設(shè)計(jì)的一個(gè)關(guān)鍵階段。</p><p>　　在這種形式中，凸輪旋轉(zhuǎn)，從動(dòng)件實(shí)現(xiàn)（通常是滾子或銷）通過凸輪端面上的槽來引導(dǎo)。凸輪旋轉(zhuǎn)使從動(dòng)件移動(dòng)。這種類型 的機(jī)構(gòu)也是幾何鎖合，它的制造費(fèi)用比簡單的盤形凸輪高很多。</p><p>　　等徑凸輪，這只是一個(gè)帶有偏心凸輪軸孔的圓盤，偏心量的大小決定了從動(dòng)件位移的大小，當(dāng)凸輪旋轉(zhuǎn)時(shí)，從動(dòng)件作往復(fù)運(yùn)動(dòng)。這種裝置有時(shí)稱為蘇格半約克機(jī)構(gòu)。從動(dòng)件運(yùn)動(dòng)時(shí)與

56、凸輪為幾何鎖合?？赏ㄟ^這種裝置得到諧和的運(yùn)動(dòng)。</p><p><b>　　從動(dòng)件的類型</b></p><p>　　總的說來，從動(dòng)件是與凸輪輪廓相接觸的零件。然而，當(dāng)用次數(shù)從動(dòng)件時(shí)，次級從動(dòng)件的運(yùn)動(dòng)就需通過主要從動(dòng)件來實(shí)現(xiàn)。比如，滾子從動(dòng)件可緊靠著擺動(dòng)從動(dòng)伯的邊緣作往復(fù)運(yùn)動(dòng)。</p><p>　　最簡單的從動(dòng)件是隨著凸輪的轉(zhuǎn)動(dòng)而僅作上下（或進(jìn)

57、出）往復(fù)運(yùn)動(dòng)的從動(dòng)件，其中心線可與凸輪中心線共線，也可與之偏離。它可通過點(diǎn)、刃口、表面或滾子與凸輪接觸。如果用點(diǎn)或表面接觸，很高的正應(yīng)力會(huì)導(dǎo)致擦傷和過量的磨損。如果凸輪傳到從動(dòng)件的力不大，問題就不大嚴(yán)重。比如，操縱一個(gè)小的速動(dòng)開關(guān)不會(huì)產(chǎn)生凸輪表面磨損。微型速動(dòng)電開關(guān)有多種形式的啟動(dòng)器，有一些是圓點(diǎn)，有一些薄金屬片。氣動(dòng)回路中的微型三通閥中有類似的啟動(dòng)器。如果凸輪用來直接驅(qū)動(dòng)機(jī)械組件，滾子就非常有效。這就是一個(gè)往復(fù)運(yùn)動(dòng)的滾子從動(dòng)件。<

58、;/p><p>　　尺寸是從0.5英寸到6英寸的凸輪滾子可以買到在，33(1/3)的轉(zhuǎn)速和最低壽命為500小時(shí)的條件下，基本受力值在620磅到60000磅內(nèi)變化。在其他轉(zhuǎn)速或壽命值下，須對基本受力值加以修正。凸輪可通過柄上的油孔或柄端上的潤滑裝置來潤滑。與表面的滾動(dòng)接觸減少了磨損問題。滾子從動(dòng)件有幾種安裝方式，安裝在擺臂上的滾子從動(dòng)件。當(dāng)用平面從動(dòng)件時(shí)須控制從動(dòng)件表面和凸輪輪廓之間的摩控。適當(dāng)?shù)臐櫥蓽p少磨擦。<