二級齒輪減速器外文翻譯

1、大連交通大學(xué)信息工程學(xué)院2014屆本科生畢業(yè)設(shè)計（論文）外文翻譯二級齒輪減速器外文翻譯The gear and shaftReducer is a dynamic communication agencies, the use of gear speed converters, motor rotational speed reducer to the Rotary to be few, and have greater torque institutions. General helical gear reducer has reducer (including parallel shaft

2、 helical gear reducer, a worm reducer, bevel gear reducei; etc.), planetary gear reducer, Cycloid reducer, a worm reducer, a planetary friction CVT mechanical machines.The important position of the wheel gear and shaft cant falter in the design of he passing to process to make them can is divided in

3、to many model numbers , using for many situations respectively .So we must be the multilayer to the understanding of the wheel gear and shaft in reducer.In the force analysis of spur gears, the forces are assumed to act in a single plane. We shall study gears in which the forces have three dimension

4、s. The reason for this, in the case of helical gears, is that the teeth are not parallel to the axis of rotation. And in the case of bevel gears, the rotational axes are not parallel to each other. There are also other reasons, as we shall learn.Helical gears are used to transmit motion between para

5、llel shafts. The helix angle is the same on each gear, but one gear must have a right-hand helix and the other a left-hand helix. The shape of the tooth is an involutes helicoids. If a piece of paper cut in the shape of a parallelogram is wrapped around a cylinder, the angular edge of the paper beco

6、mes a helix. If we unwind this paper, each point on the angular edge generates an involutes curve. The surface obtained when every point on the edge generates an involutes is called an involutes helicoids.The initial contact of spur-gear teeth is a line extending all the way across the face of the t

7、ooth. The initial contact of helical gear teeth is a point, which changes into a line as the teeth come into more engagement. In spur gears the line of contact is parallel to the axis of the rotation; in helical gears, the line is diagonal across the face of the tooth. It is this gradual of the teet

8、h and the smooth transfer of load from one tooth to another, which give helical gears the ability to transmit heavy loads at high speeds. Helical gears subject the shaft bearings to both radial and thrust loads. When the thrust loads become high or are objectionable for other reasons, it may be desi

9、rable to use double helical gears. A double helical gear (herringbone) is equivalent to two helical gears of opposite 大連交通大學(xué)信息工程學(xué)院2014屆本科生畢業(yè)設(shè)計（論文）外文翻譯hand, mounted side by side on the same shaft They develop opposite thrust reactions and thus cancel out the thrust load. When two or more single helic

10、al gears are mounted on the same shaft, the hand of the gears should be selected so as to produce the minimum thrust load.Crossed-helical, or spiral gears are those in which the shaft centerlines are neither parallel nor intersecting. The teeth of crossed-hclical fears have point contact with each o

11、ther; which changes to line contact as the gears wear in. For this reason they will carry out very small loads and are mainly for instrumental applications, and are definitely not recommended for use in the transmission of power. There is on difference between a crossed helical. Gear and helical gea

12、r until they are mounted in mesh with each other. They are manufactured in the same way. A pair of meshed crossed helical gears usually have the same hand; that is a right-hand driver goes with a right-hand driven. In the design of crossed-helical gears, the minimum sliding velocity is obtained when

13、 the helix angle are equal. Ho we ver, when the helix angle are not equals the gear w讓h the 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 c

14、ompletely 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 angular-velocity reduction between nonintersecting shafts which are usually at right angle. The worm gear is not

15、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 cither single o

16、r double enveloping, A single-enveloping 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 double-enveloping worm gearing. The important difference between the two is that area contact exists be

17、tween the teeth of double-enveloping gears while only line contact between those of single-enveloping gears. The worm and worm gear of a set have the same hand of helix as for crossed helical gears, but the helix angles arc usually quite different. The helix angle on the worm is generally quite larg

18、e, and that on the gear very small. Because of this, it is usual to specify the lead angle on the worm which is the complement of the worm helix angle，and the helix angle on the gear; the two angles are equal for a 90-deg. Shaft angle.When gears are to be used to transmit motion between intersecting

19、 shafts some of bevel gear is required. Although bevel gear are usually made for a shaft angle of 90 deg. They may be produced for almost any shaft angle. The teeth may be cast, milled, or generated. Only the generated teeth may be classed as accurate. In a typical bevel gear mountings one of the ge

20、ar is often mounted outboard of the bearing. This means that shaft deflection can be more pronounced and have a greater effect on the contact of teeth. Another difficulty, which occurs in predicting the stress in bevel -gear teeth, is the fact the teeth are tapered.Straight bevel gears are easy to d

21、esign and simple to manufacture and give very good results in service if they are mounted accurately and positively. As in the case of spur gears, however, they become noisy at higher values of the pitch-line velocity. In these cases it is often good design practice to go to the spiral bevel gear, w

22、hich is the bevel counterpart of the helical gear. As in the case of helical gears, spiral bevel gears give a much smoother tooth action than straight bevel gears, and hence are useful where high speed are encountered. It is frequently desirable, as in the case of automotive differential application

23、s, to have gearing similar to bevel gears but with the shaft offset. Such gears are called hypoid gears because their pitch surfaces are hyperboloids of revolution. The tooth action between such gears is a combination of rolling and sliding along a straight line and has much in common with that of w

24、orm gears.A shaft is a rotating or stationary member, usually of circular cross section, having mounted upon it such elements as gears, pulleys flywheels, cranks, sprockets, and other power-transmission elements. Shaft may be subjected to bending, tension, compression, or tcnsional loads, acting sin

25、gly or in combination with one another. When they are combined, one may expect to find both static and fatigue strength to be important design considerations, since a single shaft may be subjected to static stresses, completely reversed, and repeated stresses, all acting at the same time.The word “s

26、haft covers numerous variations, such as axles and spindles. An axle is a shaft, wither stationary or rotatings nor subjected to torsion load. A shirt rotating shaft is often called a spindle.When either the lateral or the tensional deflection of a shaft must be held to close limits, the shaft must

27、be sized on the basis of deflection before analyzing the stresses. The reason for this is that9 if the shaft is made stiff enough so that the deflection is not too large, it is probable that the resulting stresses will be safe. But by no means should the designer assume that they are safest is almos

28、t always necessary to calculate them so that he knows they are within acceptable limits. Whenever possible, the2大連交通大學(xué)信息工程學(xué)院2014屆本科生畢業(yè)設(shè)計（論文）外文翻譯power-transmission elements弭uch as gears or pullets, should be located close to the supporting bearings, This reduces the bending moment, and hence the defl

29、ection and bending stress.Although the von Mises-Hencky-Goodman method is difficult to use in design of shaft, it probably comes closest to predicting actual failure. Thus it is a good way of checking a shaft that has already been designed or of discovering why a particular shaft lias failed in serv

30、ice. Furthermore, there are a considerable number of shaft-design problems in which the dimension are pretty well limited by other considerations such as rigidity, and it is only necessary for the designer to discover something about the fillet sizes, heat-treatment, and surface finish and whether o

31、r not shot preening is necessary in order to achieve the required life and reliability*Because of the similarity of their functions，clutches and brakes are treated together In a simplified dynamic representation of a friction clutch, or brake, two inertias II and 12 traveling at the respective angul

32、ar velocities VV1 and V2, one of which may be zero in the case of brake, are to be brought to the same speed by engaging the clutch or brake. Slippage occurs because the two elements are running at different speeds and energy is dissipated during actuation, resulting in a temperature rise. In analyz

33、ing the performance of these devices we shall be interested in the actuating force, the torque transmitted, the energy loss and the temperature rise. The torque transmitted is related to the actuating force, the coefficient of friction, and the geometry of the clutch or brake. This is problem in sta

34、tic, which will have to be studied separately for earth geometric configuration. However, temperature rise is related to energy loss and can be studied without regard to the type of brake or clutch because the geometry of Interest is the heat-dissipating surfaces. The various types of clutches and b

35、rakes may be classified as fellows.1. Rim type with internally expanding shoes2. Rim type with externally contracting shoes3 Band type4. Disk or axial type5. Cone type6. Miscellaneous typeThe analysis of all type of friction clutches and brakes use the same general procedure. The following step are

36、necessary:L Assume or determine the distribution of pressure on the frictional surfaces.2. Find a relation between the maximum pressure and the pressure at any point.3 Apply the condition of statically equilibrium to find (a) the actuating force, (b) the torque, and (c) the support reactions.Miscell

37、aneous clutches include several types, such as the positive-contact clutches, overload-release clutches, overrunning clutches, magnetic fluid clutches, and others. A positive-contact clutch consists of a shift lever and two jaws. The greatest differences between the various types of positive clutche

38、s are concerned with the design of the Jaws. To provide a longer period of time for shift action during engagement, the Jaws may be ratchet-shaped, or gear-tooth-shaped. Sometimes a great many teeth or Jaws are used, and thev mav be cut either circumferentialhs so that thev engage bv cvlindrical mat

39、ing, or on the faces of the mating elements.Although positive clutches are not used to the extent of the frictional-contact type, they do have important applications where synchronous operation is required. Devices such as linear drives or motor-operated screw drivers must run to definite limit and

40、then come to a stop. An overloadrelease type of clutch is required for these applications. These clutches are usually spring-loaded so as to release at a predetermined toque. The clicking sound which is heard when the overload point is reached is considered to be a desirable signal.An overrunning cl

41、utch or coupling permits the driven member of a machine to “freewheel” or overmn” because the driver is stopped or because another source of power increase the speed of the driven. This type of clutch usually uses rollers or balls mounted between an outer sieve and an inner member having flats machi

42、ned around the periphery. Driving action is obtained by wedging the rollers between the sleeve and the flats. The clutch is obtained by wedging the rollers between the sleeve and the flats. The clutch is therefore equivalent to a pawl and ratchet with an infinite number of teeth.Magnetic fluid clutc

43、h or brake is a relatively new development which has two parallel magnetic plates. Between these plates is a lubricated magnetic powder mixture. An electromagnetic coil is inserted somewhere in the magnetic circuit. By varying the excitation to this coil, the shearing strength of the magnetic fluid

44、mixture may be accurately controlled. Thus any condition from a full slip to a frozen lockup may be obtained 大連交通大學(xué)信息工程學(xué)院2014屆本科生畢業(yè)設(shè)計（論文）外文翻譯齒輪和軸的介紹減速器是一種動力傳達機構(gòu)，利用齒輪的速度轉(zhuǎn)換器，將馬達的回轉(zhuǎn)數(shù)減速到所要 的回轉(zhuǎn)數(shù)，并得到較大轉(zhuǎn)矩的機構(gòu)。一般的減速器有斜齒輪減速器（包括平行軸斜齒輪 減速器、蝸輪減速器、錐齒輪減速器等等）、行星齒輪減速器、擺線針輪減速器、蝸輪 蝸桿減速器、行星摩擦式機械無級變速機等等。在減速器設(shè)計中齒輪和軸的重要地位

45、是不可動搖的。齒輪和軸主要安裝在主軸箱來 傳遞力的方向。通過加工制造它們可以分為許多的型號，分別用于許多的場合。所以我 們對齒輪和軸的了解和認識必須是多層次多方位的。在直齒圓柱齒輪的受力分析中，是假定各力作用在單一平面的。我們將研究作用力 具有三維坐標(biāo)的齒輪。因此，在斜齒輪的情況下，其齒向是不平行于回轉(zhuǎn)軸線的。而在 錐齒輪的情況中各回轉(zhuǎn)軸線互相不平行。這還有其他道理值得我們學(xué)習(xí)就像我們討論的 那樣。斜齒輪用于傳遞平行軸之間的運動。傾斜角度每個齒輪都一樣，但一個必須是右旋 斜齒，而另一個必須是左旋斜齒。齒的形狀是一漸開線螺旋面。如果一張被剪成平行四 邊形（矩形）的紙張包圍在齒輪圓柱體上，紙上印出

46、齒的角刃邊就變成斜線。如果我展 開這張紙，在血角刃邊上的每一個點就發(fā)生一漸開線曲線。直齒圓柱齒輪輪齒的初始接觸處是跨過整個齒面而伸展開來的線。斜齒輪輪齒的初 始接觸是一點，當(dāng)齒進入更多的嚙合時，它就變成線。在直齒圓柱齒輪中，接觸線是平 行于回轉(zhuǎn)軸線的。在斜齒輪中，該線是跨過齒面的對角線。它是齒輪逐漸進行嚙合并平 穩(wěn)的從一個齒到另一個齒傳遞運動，那樣就使斜齒輪具有高速重載下平穩(wěn)傳遞運動的能 力。斜齒輪使軸的軸承承受徑向和軸向力。當(dāng)軸向推力變得大了或由于別的原因而產(chǎn)生 某些影響時，那就可以使用人字齒輪。雙斜齒輪（人字齒輪）是與反向并排地裝在同一 軸上的兩個斜齒輪等效。他們產(chǎn)生相反的軸向推力作用，這

47、樣就消除了軸向推力。當(dāng)兩 個或更多個單向齒斜齒輪被安裝在同一軸上時，齒輪的齒向應(yīng)作選擇，以便產(chǎn)生最小的 軸向推力。交錯軸斜齒輪或螺旋齒輪，他們是軸中心線既不相交也不平行。交錯軸斜齒輪的齒 彼此之間發(fā)生點接觸，它隨著齒輪的磨合而變成線接觸。因此他們只能傳遞小的載荷和 主要用于儀器設(shè)備中，而且肯定不能推薦在動力傳動中使用。交錯軸斜齒輪與斜齒輪之 間在被安裝后互相嚙合之前是沒有任何區(qū)別的。它們是以同樣的方法進行制造。一對相 嚙合的交錯軸斜齒輪通常具有同樣的齒向，即右旋主動齒輪跟右旋從動齒輪相嚙合。在 交錯軸斜齒設(shè)計中，當(dāng)該齒的斜角相等時所產(chǎn)生滑移速度最小。然而當(dāng)該齒的斜角不相 等時，如果兩個齒輪具有

48、相同齒向的話，大斜角齒輪應(yīng)用作主動齒輪。蝸輪與交錯軸斜齒輪相似，小齒輪即蝸桿具有較小的齒數(shù)，通常是一到四齒，由于 它們完全纏繞在節(jié)圓柱上，因此它們被稱為螺紋齒。與其相配的齒輪叫做蝸輪，蝸輪不 是真正的斜齒輪。蝸桿和蝸輪通常是用于向垂直相交軸之間的傳動提供大的角速度減速 比。蝸輪不是斜齒輪，因為其齒頂面做成中凹形狀以適配蝸桿曲率，目的是要形成線接 觸而不是點接觸。然而就像交錯軸斜齒輪那樣，蝸桿蝸輪傳動機構(gòu)中存在齒間有較大滑 移速度的缺點。蝸桿蝸輪機構(gòu)有單包圍和雙包圍機構(gòu)。單包圍機構(gòu)就是蝸輪包裹或部分包裹著蝸桿 的一種機構(gòu)。當(dāng)然，如果每個構(gòu)件各自局部地包圍著對方的蝸輪機構(gòu)就是雙包圍蝸輪蝸 桿機構(gòu)。

49、這兩者之間的重要區(qū)別是，在雙包圍蝸輪組的輪齒間有面接觸，而在單包圍的 蝸輪組的輪齒間有線接觸。一個裝置中的蝸桿和蝸輪正像交錯軸斜齒輪那樣具有相同的 齒向，但是其斜齒齒角的角度是不相同的。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)角就是蝸桿齒輪斜角的余角；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。當(dāng)齒輪是用來傳遞相交軸之間的運動時，就需要某種形式的錐齒輪。雖然錐齒輪通 常制造成能構(gòu)成90度軸交角，但它們也可產(chǎn)生任何角度的軸交角。輪齒可以鑄出、銃 制或滾切加工。僅就滾齒而言就可達一級精度。在典型的錐齒輪安裝中，其中一個錐齒 輪常常裝于支承的外側(cè)。這意味著軸的撓曲情況更加明顯而使在輪齒接觸上具有更大的 影響。另外一個難題，發(fā)生在難于預(yù)示錐齒輪輪齒上的應(yīng)力，實際上是由于齒輪被加工 成錐狀造成的。直齒錐齒輪易于設(shè)計且制造簡單，如果他們安裝的精密確定，在運轉(zhuǎn)中會產(chǎn)生良好 的效果。然而在直齒圓柱齒輪情況下，在節(jié)線速度較高時，他們將發(fā)出噪音。在這些情 況下，螺旋錐齒輪比直齒輪能產(chǎn)生平穩(wěn)的多的嚙合作用，因此碰到高速運轉(zhuǎn)的場合那是 很有用的。當(dāng)在汽車的各種不同用途中，有一個帶偏心軸的類似錐齒輪的機構(gòu)，那是常 常所希望的。這樣的齒輪機構(gòu)叫做準(zhǔn)雙曲面齒輪機構(gòu)，因為它們的節(jié)面是雙曲回轉(zhuǎn)面。 這種齒輪之間的輪齒作用是沿著一根直線上產(chǎn)生滾動與滑動相結(jié)合的