機械設計 外文翻譯 外文文獻 英文文獻及譯文 齒輪和軸的介紹

1、譯文一：譯文 齒輪和軸的介紹摘要:在傳統(tǒng)機械和現代機械中齒輪和軸的重要地位是不可動搖的。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。關鍵詞:齒輪；軸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的齒輪。因此，在斜齒輪的情況下，其齒向是不平行于回轉軸線的。而在錐齒輪的情況中各回轉軸線互相不平行。像我們要討論的那樣，尚有其他道理需要學習，掌握。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，但一個必須右旋斜齒，而另一個必須是左旋斜齒。齒的形狀是一濺開

2、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，當齒進入更多的嚙合時，它就變成線。在直齒圓柱齒輪中，接觸是平行于回轉軸線的。在斜齒輪中，該先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。當軸向推力變的大了或由于別的原因而產生某些影響時，那就可以使用人字齒輪。雙斜齒輪（人字齒輪）是與反向的并排

3、地裝在同一軸上的兩個斜齒輪等效。他們產生相反的軸向推力作用，這樣就消除了軸向推力。當兩個或更多個單向齒斜齒輪被在同一軸上時，齒輪的齒向應作選擇，以便產生最小的軸向推力。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捏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，即左旋主動齒輪跟右旋從動齒輪相嚙合。在交錯軸斜齒設計中，當該齒的斜角相等時所產生滑移速度最小。

4、然而當該齒的斜角不相等時，如果兩個齒輪具有相同齒向的話，大斜角齒輪應用作主動齒輪。蝸輪與交錯軸斜齒輪相似。小齒輪即蝸桿具有較小的齒數，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。然而蝸桿蝸輪傳動機構中存在齒間有較大滑移速度的缺點，正像交錯軸斜齒輪那樣。蝸桿蝸輪機構有單包圍和雙包圍機構。單包圍機構就是蝸輪包裹著蝸桿的一種機構。當然，如果每個構件各自局部地包圍著對方的蝸輪機構就是雙

5、包圍蝸輪蝸桿機構。著兩者之間的重要區(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極不相同的。蝸桿上的齒斜角度通常很大，而蝸輪上的則極小，因此習慣常規(guī)定蝸桿的導角，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。當齒輪要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成90度軸交角，但它們也可產生任何角度的軸交角。輪齒可以鑄出，銑制或滾切加工。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。

6、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)生在難于預示錐齒輪輪齒上的應力，實際上是由于齒輪被加工成錐狀造成的。直齒錐齒輪易于設計且制造簡單，如果他們安裝的精密而確定，在運轉中會產生良好效果。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生平穩(wěn)的多的嚙合作用，因此碰到高速運轉的場合那是很有用的。當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，那是常常所希望的。這樣的齒輪機構叫做準雙曲面齒輪機構，因為它們的節(jié)面是雙曲回轉面。這種齒輪之間的輪齒作用是沿著一根直線上產生滾動與滑動相結合的運動并和蝸輪蝸桿的輪

7、齒作用有著更多的共同之處。譯文一：原文gear and shaft introductionabstract: the important position of the wheel gear and shaft cant falter in traditional machine and modern machines.the wheel gear and shafts mainly install the direction that delivers the dint at the principal axis box.the passing to process to make the

8、m can is divided into many model numbers, useding for many situations respectively.so we must be the multilayers to the understanding of the wheel gear and shaft in many ways .key words: wheel gear;shaftin the force analysis of spur gears, the forces are assumed to act in a single plane. we shall st

9、udy gears in which the forces have three dimensions. 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.heli

10、cal gears are used to transmit motion between parallel 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 involute helicoid. if a piece of paper cut in the shape of a parallelogram is wrapped aroun

11、d a cylinder, the angular edge of the paper becomes a helix. if we unwind this paper, each point on the angular edge generates an involute curve. the surface obtained when every point on the edge generates an involute is called an involute helicoid.the initial contact of spur-gear teeth is a line ex

12、tending all the way across the face of the tooth. 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

13、of the tooth. it is this gradual of the teeth 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 obj

14、ectionable for other reasons, it may be desirable to use double helical gears. a double helical gear (herringbone) is equivalent to two helical gears of opposite 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

15、 single helical 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-helical fears have point conta

16、ct with each other, 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 an

17、d a helical gear 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

18、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

19、four, and since they completely 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.

20、 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 geari

21、ng are either single or 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

22、area contact exists between 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 are usually quite different. the helix angle on the worm i

23、s 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 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 mot

24、ion between intersecting shaft, 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

25、 mounting, one of the gear 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 b

26、evel gears are easy to design and simple to manufacture and give very good results in service if they are mounted accurately and positively. as in the case of squr 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

27、the spiral bevel gear, which 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 d

28、ifferential applications, 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 i

29、n common with that of worm gears.譯文二：譯文機械設計理論機械設計是一門通過設計新產品或者改進老產品來滿足人類需求的應用技術科學。它涉及工程技術的各個領域，主要研究產品的尺寸、形狀和詳細結構的基本構思，還要研究產品在制造、銷售和使用等方面的問題。 進行各種機械設計工作的人員通常被稱為設計人員或者機械設計工程師。機械設計是一項創(chuàng)造性的工作。設計工程師不僅在工作上要有創(chuàng)造性，還必須在機械制圖、運動學、工程材料、材料力學和機械制造工藝學等方面具有深厚的基礎知識。 如前所訴，機械設計的目的是生產能夠滿足人類需求的產品。發(fā)明、發(fā)現和科技知識本身并不一定能給人類帶來好處，只

30、有當它們被應用在產品上才能產生效益。因而，應該認識到在一個特定的產品進行設計之前，必須先確定人們是否需要這種產品。 應當把機械設計看成是機械設計人員運用創(chuàng)造性的才能進行產品設計、系統(tǒng)分析和制定產品的制造工藝學的一個良機。掌握工程基礎知識要比熟記一些數據和公式更為重要。僅僅使用數據和公式是不足以在一個好的設計中做出所需的全部決定的。另一方面，應該認真精確的進行所有運算。例如，即使將一個小數點的位置放錯，也會使正確的設計變成錯誤的。 新設計本身會有許多缺陷和未能預料的問題發(fā)生，只有當這些缺陷和問題被解決之后，才能體現出新產品的優(yōu)越性。因此，一個性能優(yōu)越的產品誕生的同時，也伴隨著較高的風險。應該強調

31、的是，如果設計本身不要求采用全新的方法，就沒有必要僅僅為了變革的目的而采用新方法。在設計的初始階段，應該允許設計人員充分發(fā)揮創(chuàng)造性，不受各種約束。即使產生了許多不切實際的想法，也會在設計的早期，即繪制圖紙之前被改正掉。只有這樣，才不至于堵塞創(chuàng)新的思路。通常，要提出幾套設計方案，然后加以比較。很有可能在最后選定的方案中，采用了某些未被接受的方案中的一些想法。心理學家經常談論如何使人們適應他們所操作的機器。設計人員的基本職責是努力使機器來適應人們。這并不是一項容易的工作，因為實際上并不存在著一個對所有人來說都是最優(yōu)的操作范圍和操作過程。 另一個重要問題，設計工程師必須能夠同其他有關人員進行交流和磋

32、商。在開始階段，設計人員必須就初步設計同管理人員進行交流和磋商，并得到批準。這一般是通過口頭討論，草圖和文字材料進行的。為了進行有效的交流 ，需要解決下列問題： （1）所設計的這個產品是否真正為人們所需要？ （2）此產品與其他公司的現有同類產品相比有無競爭能力？ （3）生產這種產品是否經濟？ （4）產品的維修是否方便？ （5）產品有無銷路？是否可以盈利？ 只有時間能對上述問題給出正確答案。但是， 產品的設計、制造和銷售只能在對上述問題的初步肯定答案的基礎上進行。設計工程師還應該通過零件圖和裝配圖，與制造部門一起對最終設計方案進行磋商。 通常 ，在制造過程中會出現某個問題?？赡軙髮δ硞€零件尺

33、寸或公差作一些更改，使零件的生產變得容易。但是，工程上的更改必須要經過設計人員批準，以保證不會損傷產品的功能。有時，在產品的裝配時或者裝箱外運前的試驗中才發(fā)現設計中的某種缺陷。這些事例恰好說明了設計是一個動態(tài)過程?？偸谴嬖谥玫姆椒▉硗瓿稍O計工作，設計人員應該不斷努力，尋找這些更好的方法。譯文二：原文mechanical design theorythe mechanical design is a application technical science through design the new product or improves the old product to meet

34、the human need. it involves all domain of the project technology, mainly research size of the product , basic idea of the shape and the detailed structure, also research question of manufacture , sale and use of the product in all aspects. they usually called designer or mechanical design engineer w

35、ho carries on each kind of mechanical design work. the mechanical design is a creative work. design engineer not only have，the creativity in the work, but also have the deep elementary knowledge on mechanical drawing, kinematics, engineering material, materials mechanics and machine manufacture tech

36、nology. as says above, the goal of mechanical design is the production can meet the human need. the invention, the discovery and technical knowledge itself certainly not necessarily can bring the advantage to the humanity, only when they are applied on the product can produce the benefit. thus, we s

37、hould realize whether people do need this kind of product before carry on the design in a specific product. the mechanical design must regard as a good opportunity for the mechanical designer to use creative ability carries on product design, the systematic analysis and formulate manufacture technol

38、ogy of the product. grasping the project elementary knowledge is more important than memorizing some data and the formula. merely using the data and the formula is insufficient to completely decide all decision in a good design. on the other hand, they should carry on all operations precisely. for e

39、xample, even if place a decimal point in wrong position, also can turn the correct design to wrong. new designs can have many flaws and problems unexpected, only these flaws and the question have been solved, can new products superiority be manifested. therefore,a superior product born followed a hi

40、gher risk at the same time. what should emphasize is that if designs itself does not request to use the brand-new method, it is not necessary to use the new method merely for the goal for transformation. in the preliminary stage of design, should allow designer fully to display the creativity, not r

41、estraint to each kind of restraint. even if have many impractical ideas in early time, they can also be corrected before plan blueprint. only in this way can not stop the innovation. usually, must propose several sets of design proposals, and then perform the comparison. it is possible that some ide

42、as have been used in the final plan which is not accepted before. the psychologist frequently discusses the causes of how could people adapt to machine which operate. a designers personnels basic responsibility is diligently causes the machine to adapt the people. this certainly is not an easy work,

43、 because the most superior operating area and the operating process to all do not exist in fact. another important question, project engineer must be able to carry on the exchange the consultation with other concerned personnel. in the initial stage, designer has to exchange with administrator on the preliminary design, and be approved. this is generally through the oral discussion, with schematic diagram and the writing material. in or