240t焊接滾輪架設(shè)計(jì)-主動(dòng)滾輪座設(shè)計(jì)（全套含CAD圖紙）

喜歡這套資料就充值下載吧。資源目錄里展示的都可在線預(yù)覽哦。下載后都有，請(qǐng)放心下載，文件全都包含在內(nèi)，【有疑問咨詢QQ:1064457796 或 1304139763】 =喜歡這套資料就充值下載吧。資源目錄里展示的都可在線預(yù)覽哦。下載后都有，請(qǐng)放心下載，文件全都包含在內(nèi)，【有疑問咨詢QQ:1064457796 或 1304139763】 = 畢業(yè)設(shè)計(jì)（論文）任務(wù)書專業(yè) 機(jī)械設(shè)計(jì)制造及其自動(dòng)化 班級(jí) 機(jī)械052 姓名 王曉光 下發(fā)日期 2009-3-12題目240t焊接滾輪架設(shè)計(jì)專題主動(dòng)滾輪座設(shè)計(jì)主要內(nèi)容及要求主要內(nèi)容：完成240t焊接滾輪架的主動(dòng)滾輪座設(shè)計(jì)。編寫設(shè)計(jì)說明書，繪制裝配圖及部分零件圖。要求：必須以負(fù)責(zé)的態(tài)度對(duì)待自己所做的技術(shù)決定、數(shù)據(jù)和計(jì)算結(jié)果。在教師指導(dǎo)下，獨(dú)立完成設(shè)計(jì)任務(wù)，培養(yǎng)較強(qiáng)的創(chuàng)新意識(shí)和學(xué)習(xí)能力，獲得機(jī)械工程師的基本訓(xùn)練。整個(gè)設(shè)計(jì)在技術(shù)上是先進(jìn)的，在經(jīng)濟(jì)上是合理的，在生產(chǎn)上是可行的。計(jì)算步驟清晰，計(jì)算結(jié)果正確；圖面整潔，視圖齊全，布局合理，線條、文字及尺寸標(biāo)注符合國家標(biāo)準(zhǔn)；使用計(jì)算機(jī)設(shè)計(jì)、計(jì)算和繪圖；設(shè)計(jì)說明書要求內(nèi)容完整，文字通順，語言簡(jiǎn)練，圖示清晰，重要計(jì)算公式和數(shù)據(jù)應(yīng)注明出處。設(shè)計(jì)說明書不少于2萬字，查閱文獻(xiàn)15篇以上，翻譯與課題有關(guān)的英文資料2篇，譯文字?jǐn)?shù)不少于5千漢字，繪制圖紙折合總量不少于5張A1。主要技術(shù)參數(shù)載重量240103 kg，工件最大直徑6000 mm，滾輪圓周速度660 m/h，滾輪直徑600 mm，驅(qū)動(dòng)功率21.4 k W 進(jìn)度及完成日期3月 23日 4 月 12日（3周）：課題調(diào)研，理解熟悉設(shè)計(jì)任務(wù)，借閱資料，翻譯英文文獻(xiàn)，制訂設(shè)計(jì)計(jì)劃。4月 13日 4 月26日（2周）： 方案設(shè)計(jì)，選擇確定機(jī)器總體方案及部件方案。4月 27日 5 月 31日（5周）：技術(shù)設(shè)計(jì)，在草圖的基礎(chǔ)上完成裝配圖和零件圖的繪制。6月 1日 6 月 14日（2周）：技術(shù)文件編制，編寫完成畢業(yè)設(shè)計(jì)說明書，打印圖紙，上交說明書和圖紙。6月 15日 6 月 21日（1周）： 教師審閱畢業(yè)設(shè)計(jì)，學(xué)生準(zhǔn)備答辯。教學(xué)院長(zhǎng)簽字日 期教研室主任簽字日 期指導(dǎo)教師簽字日 期指 導(dǎo) 教 師 評(píng) 語 指導(dǎo)教師: 年 月 日指 定 論 文 評(píng) 閱 人 評(píng) 語 評(píng)閱人: 年 月 日答 辯 委 員 會(huì) 評(píng) 語評(píng)定成績(jī)指導(dǎo)教師給定成績(jī)(30%)評(píng)閱人給定成績(jī)(30%)答辯成績(jī)（40%）總 評(píng)答辯委員會(huì)主席簽字青島理工大學(xué)本科畢業(yè)設(shè)計(jì)（論文）說明書外文翻譯一 輪軸圖1火車的車輪安裝在車軸上，兩個(gè)輪同步轉(zhuǎn)動(dòng)。這被稱為輪軌。一個(gè)軸是中央軸用來承載滾輪和齒輪。著某些情況下，車軸也可以用來承載被安裝在滾輪和齒輪中的軸承和軸承墊，以使他們圍繞軸旋轉(zhuǎn)。在另外一些情況下，輪和齒輪也許會(huì)被直接固定在軸上，通過軸承來支撐軸，這種情況在自行車上最為常見。1交通工具的軸車軸是有輪交通工具的必不可少的一個(gè)部分。車軸維持著車輪及車輪和整體的位置關(guān)系。對(duì)于大多數(shù)交通工具來說，車輪是唯一與地面接觸的部分。車軸承載著運(yùn)輸裝置和其上的貨物的所有的總量，還有加速度，和顛簸時(shí)的沖擊力。以結(jié)構(gòu)力學(xué)的觀點(diǎn)來看，軸必須協(xié)調(diào)好與下列設(shè)備的關(guān)系。驅(qū)動(dòng)器：一個(gè)或多個(gè)車軸都是動(dòng)力系統(tǒng)的一部分，一個(gè)機(jī)械系統(tǒng)都會(huì)將轉(zhuǎn)動(dòng)的力作用在軸上，使之能夠傳動(dòng)力到輪，一邊去動(dòng)整個(gè)運(yùn)輸裝置。剎車系統(tǒng)：相反的當(dāng)運(yùn)載裝置想要停下來時(shí)，它就會(huì)提供一個(gè)力給車軸，通過摩擦力來使車輛停下來，當(dāng)車子停下來時(shí)由于發(fā)動(dòng)機(jī)還在旋轉(zhuǎn)，也就是說軸依然在承受負(fù)載。導(dǎo)向：大部分小型汽車的前輪都是用來導(dǎo)向的，運(yùn)輸工具通過改變前輪軸來改變前輪和車身的朝向，以便調(diào)整車的運(yùn)行方向。2結(jié)構(gòu)特點(diǎn)圖2 O系列新干線的車輪直軸是一種連接左輪和右輪的裝置。車軸的中心線在兩個(gè)輪的正中間，這樣設(shè)計(jì)可以保證輪的位置能夠在承受壓力是不至于改變。直軸常用于火車、民用汽車的后軸，以及承受巨大載荷的非道路運(yùn)載工具。在拆分設(shè)計(jì)時(shí)車輪附在軸的一個(gè)端上。在某些設(shè)計(jì)中它允許允許左輪和右輪獨(dú)立懸在車身下，這通過一個(gè)減震橋來實(shí)現(xiàn)，這樣就可以保證車身在行駛時(shí)能夠不太顛簸。當(dāng)軸不是懸掛式的時(shí)，分開車軸可以通過左輪和右輪分別以不同速度驅(qū)動(dòng)車體來使車輛轉(zhuǎn)彎和保證平穩(wěn)。一個(gè)串聯(lián)軸是兩個(gè)或兩個(gè)以上的軸安裝在一起組成的。卡車通常會(huì)使用多個(gè)軸來提供一個(gè)軸所不能提供的運(yùn)載能力，自卸式卡車通常在后輪處有一個(gè)串聯(lián)軸。3驅(qū)動(dòng)軸圖3驅(qū)動(dòng)軸前段的花健一個(gè)被發(fā)動(dòng)機(jī)驅(qū)動(dòng)的軸被稱作驅(qū)動(dòng)軸。現(xiàn)代前輪驅(qū)動(dòng)車可以融合一個(gè)驅(qū)動(dòng)和前輪為一個(gè)單位，我們稱之為橋。驅(qū)動(dòng)輪是一個(gè)的被萬向分離接頭連接的兩個(gè)軸。每一個(gè)軸都和車輪用一個(gè)等速連軸器連接，它允許車輪在轉(zhuǎn)向時(shí)也能良好的傳遞動(dòng)力。在后輪驅(qū)動(dòng)的汽車和卡車中，發(fā)動(dòng)機(jī)驅(qū)動(dòng)一個(gè)驅(qū)動(dòng)軸它將發(fā)動(dòng)機(jī)的旋轉(zhuǎn)里傳遞給車后部的驅(qū)動(dòng)軸。這些驅(qū)動(dòng)也許是一個(gè)活動(dòng)軸，但現(xiàn)代設(shè)計(jì)通常一個(gè)分裂軸來表明他們的不同。一些簡(jiǎn)單的運(yùn)輸工具的設(shè)計(jì)，例如卡丁車，也許只有一個(gè)驅(qū)動(dòng)輪。這個(gè)驅(qū)動(dòng)軸是一個(gè)分裂軸，分別被不同的發(fā)動(dòng)機(jī)所驅(qū)動(dòng)。4死軸和懶軸圖4這個(gè)大卡車擁有一個(gè)龐大的驅(qū)動(dòng)軸死橋 ，也稱為懶惰車軸 ，不傳遞動(dòng)力而是自由旋轉(zhuǎn)。后軸驅(qū)動(dòng)的汽車的前軸可被視為死軸。許多卡車和拖車使用死軸來保證載重量。一個(gè)死軸緊挨著一個(gè)驅(qū)動(dòng)軸被稱為推軸。一些自卸車和拖車被裝配了空軸，它們被安裝的也許高也許低。當(dāng)軸被降低時(shí)是為了提高他們的載重量，或者是為了平均的分配貨物的載重量到各個(gè)輪，例如通過一個(gè)載重橋。當(dāng)它們沒用用時(shí)，就把他們拆除，以節(jié)省動(dòng)力，減輕各個(gè)輪的負(fù)載。同時(shí)也能夠使整個(gè)運(yùn)載設(shè)備結(jié)構(gòu)更加緊湊。許多廠商提供數(shù)控空軸，這樣當(dāng)主軸達(dá)到他們總量極限時(shí)，死軸就會(huì)被自動(dòng)放低，當(dāng)有必要時(shí)，死軸也可以被立即提升，只需要按一個(gè)按鈕。外文翻譯二 齒輪圖1破舊的時(shí)鐘和暴露的齒輪.圖2 現(xiàn)代單階行星齒輪軸作用在微馬力電機(jī)上1.齒輪概述齒輪是一種安裝在傳動(dòng)裝置上，通過齒與齒的咬合傳播力的裝置單位。齒輪不同于滾輪和滑輪的地方就是在于齒輪表面有層層的齒和牙，這些齒與牙咬合與其他的齒與牙，從而使力傳播到其他的地方而不至于產(chǎn)生滑動(dòng)。根據(jù)結(jié)構(gòu)和安裝方法的不同同一種齒輪可以以不同的方式傳播運(yùn)動(dòng)，可以從動(dòng)力源處傳播不同的速度和運(yùn)動(dòng)方向。齒輪最常見的安裝形式是和其他的齒輪咬合，但齒輪可以和任何具備合適齒的裝置咬合，比如傳動(dòng)鏈。齒輪的最重要的特性是齒輪的尺寸（直徑）可以被定制為某個(gè)特定數(shù)字，以便服務(wù)于機(jī)械利益。這就造成了與齒輪膠合的齒輪的轉(zhuǎn)速和齒數(shù)不同于第一個(gè)齒輪。在特定機(jī)器的背景下，齒輪組往往代表了一個(gè)特定的齒輪膠合。這種齒輪組的咬合蘊(yùn)含著特定的轉(zhuǎn)動(dòng)比率，他通過齒數(shù)和齒輪的半徑來實(shí)現(xiàn)。2.機(jī)械利益圖3運(yùn)動(dòng)中的齒輪組對(duì)于齒輪組來說，他們的咬合運(yùn)動(dòng)決定了他們的運(yùn)動(dòng)線速度必然是相等的。線速度是齒輪的角速度與他的半徑的乘積，我們可以看到在相同的線速度下，齒輪半徑越大的齒輪運(yùn)轉(zhuǎn)的越慢。這種結(jié)論同樣可以被另外一種分析過程所印證：數(shù)齒數(shù)。因?yàn)閮蓚€(gè)咬合齒輪的齒是一個(gè)緊咬著另外一個(gè)齒。當(dāng)小齒輪的所有的齒都經(jīng)過空間里的同一點(diǎn)時(shí)，小齒輪旋轉(zhuǎn)了一周，與此同時(shí)，大齒輪的齒并沒有都經(jīng)過同一個(gè)點(diǎn)，也就是說大齒輪并沒有旋轉(zhuǎn)一周。在同一給定時(shí)間內(nèi)，小齒輪轉(zhuǎn)的圈數(shù)更多，它的速度就更快。它們的速度比與它們的次數(shù)比成反比。(速度 A * 齒數(shù) A) = (速度 B * 齒數(shù) B)這個(gè)比率也就是常見的齒輪齒數(shù)比。扭矩的確定與通過齒輪齒施加于其他齒的力有關(guān)?？紤]到兩個(gè)齒輪是通過一個(gè)接觸點(diǎn)傳播力的，一般情況下，這部分力有徑向分力和切相分力。徑向分力可以忽略不計(jì)：它只是造成輕微側(cè)滑進(jìn)且并對(duì)轉(zhuǎn)動(dòng)無影響。自由切線部分造成轉(zhuǎn)動(dòng)。扭矩等于切向部分的力乘以半徑。因此我們可以看到大齒輪傳遞著大的扭矩，而小齒輪傳遞的扭矩則較小。扭矩比等于半徑比，這正好和速度比相反，較大的扭矩意味著較小的速度，反之亦然。事實(shí)上扭矩比與速度比相反也可以從能量守恒定律中推導(dǎo)出來。在這里我們忽略了摩擦力的作用。速度比確實(shí)與此輪的齒數(shù)和尺寸有關(guān)，但是摩擦力將導(dǎo)致扭矩比實(shí)際上較速度比小。在上面的討論中我們已經(jīng)提到了齒輪的半徑。由于齒輪不是一個(gè)完全的圓，而是一個(gè)粗糙的圓。實(shí)際上他并沒有半徑。但是，對(duì)于一對(duì)嚙合齒輪，一個(gè)齒輪可以被考慮成擁有一個(gè)半徑，叫做分度圓，這個(gè)圓被認(rèn)為能產(chǎn)生相同的運(yùn)動(dòng)效果。，它被認(rèn)為是一個(gè)齒輪的平均半徑，也就是齒頂半徑與齒根半徑的平均值。對(duì)于分度圓的討論引出了一個(gè)問題也就是當(dāng)齒輪膠合時(shí)，在他們交合處的接觸情況是復(fù)雜的，也就是里的方向是復(fù)雜的。結(jié)果就是速度比（扭矩比）并非事實(shí)上也就是并非始終如一的，如果有人考慮到一對(duì)齒輪齒咬合時(shí)的細(xì)節(jié)，速度和扭矩在這一過程之中是非常散亂的，與一個(gè)長(zhǎng)期的平均值比較，特定時(shí)間地點(diǎn)的速度扭矩值是不同的。事實(shí)上通過選擇齒輪的齒形可以保證速度比率始終平穩(wěn)，不管是長(zhǎng)期的還是短期的。高質(zhì)量的齒輪往往都這么做。因?yàn)樗俣鹊牟▌?dòng)往往造成機(jī)器的震動(dòng)，同時(shí)對(duì)齒輪齒造成額外的壓力，則會(huì)導(dǎo)致齒輪齒在高速度和高載荷下破裂。平穩(wěn)的速度往往也是某些高精度儀器的必備要求，例如鐘表和手表。漸開線齒輪齒形非常適合傳遞平穩(wěn)的速度，它也是現(xiàn)在最常用的一種齒形。3.與其他傳動(dòng)裝置的比較具有明確的轉(zhuǎn)速比，在對(duì)于有高精度要求的地方，例如手表等依靠高精度齒輪傳動(dòng)的地方，齒輪比其他傳動(dòng)形勢(shì)（例如牽引輪和V帶）有著明顯的優(yōu)勢(shì)。在驅(qū)動(dòng)部分與沖動(dòng)部分緊挨著的地方，齒輪傳動(dòng)可以有效的降低傳動(dòng)部件的數(shù)目。齒輪的缺點(diǎn)就是齒輪的制造成本很高，另外齒輪需要潤(rùn)滑，這也給齒輪的保養(yǎng)增添了許多額外的支出。微型交通工具特別適合多種齒輪的組合，并最能體現(xiàn)它的機(jī)械優(yōu)勢(shì)。4.齒輪類型4.1外部與內(nèi)部齒輪與大多數(shù)齒輪不同，內(nèi)部齒輪不會(huì)導(dǎo)致方向逆轉(zhuǎn)。 外部齒輪就是牙齒上形成的外表面是圓柱或圓錐形。相反，內(nèi)部齒輪是與牙齒位于圓柱或圓錐形的內(nèi)表面。對(duì)于錐齒輪，內(nèi)部齒輪的俯仰角超過90度。4.2正齒輪齒輪是最簡(jiǎn)單和最常見的一種裝置。其一般形式是一個(gè)碟型或磁盤型。具有輻射狀的牙齒，并且具備“直切齒輪” ，牙齒排列平行在盤的外緣。要使這些齒輪成功的嚙合在一起，要求齒輪被正確安裝到平行車軸上。4.3螺旋齒輪圖4 齒輪組中的的螺旋齒輪螺旋齒輪是一種做了細(xì)微改良的直齒圓柱齒輪。邊緣牙齒做不平行的軸旋轉(zhuǎn)，并以以某種角度存在。由于齒輪是彎曲的，這也順勢(shì)造成了齒形是螺旋狀的。牙齒的角度的過渡直齒圓柱齒輪的牙齒角度過度更平穩(wěn)。這也造成了螺旋齒輪運(yùn)行比正齒輪更加平穩(wěn)和安靜。螺旋齒輪還提供一種使用非平行軸的可能性。一對(duì)螺旋齒輪可以一兩種形式嚙合：運(yùn)行軸平行嚙合或中心軸成一定角度嚙合。這些配置被稱為平行或交叉，分別。平行配置更具有機(jī)械代表性。其中，一對(duì)螺旋齒輪的嚙合齒必須滿足有可以重合的齒面切線，以及它們的分度圓切線也必須遵守上述規(guī)則，一般來說，一個(gè)曲線延伸一段距離，它們將面臨的一定的錯(cuò)開寬度。對(duì)于交叉配置，螺旋齒不符合切線原理，只能在點(diǎn)接觸齒面內(nèi)實(shí)現(xiàn)。由于是小面積的接觸，交叉螺旋齒輪只能用于輕負(fù)載。4.4準(zhǔn)雙曲面齒輪準(zhǔn)雙曲面齒輪與螺旋錐齒輪相似，但軸與軸之間存在偏移，不交叉。球行表面出現(xiàn)錐形，但以齒的補(bǔ)償?shù)窒S，實(shí)際上是螺旋錐形齒的革新，準(zhǔn)雙曲面齒輪幾乎和軸成90度。這取決于哪一方的軸的角度被抵消，相對(duì)于螺旋傘齒輪雙曲線齒輪甚至可能嚙合運(yùn)行更加順利。此外，齒輪設(shè)計(jì)中，可以用螺旋錐齒輪達(dá)到更大的減速比，即使用一套單一的準(zhǔn)雙曲面齒輪就可以使減速比率達(dá)到60:1甚至更高是“完全可行的”。4.5蝸桿蝸桿是一類似于螺絲齒輪。這是一種的特別的螺旋齒輪，但它的螺旋角通常是有點(diǎn)大（例如，有些接近90度）并且它的身體通常是分布在相當(dāng)長(zhǎng)的軸線方向，它是這些特性，使其有點(diǎn)像螺釘。 蝸桿通常一個(gè)被網(wǎng)狀齒圍著的盤形齒輪，它被稱為“齒輪”“輪”“渦輪”“蝸桿”，在渦輪蝸桿系統(tǒng)中，它允許幾個(gè)部件在一個(gè)很小的空間內(nèi)實(shí)現(xiàn)很大的傳動(dòng)比。在實(shí)際中，齒輪減速比往往低于10:1 ;而蝸輪組傳動(dòng)比通常在10:1與100:1之間，甚至達(dá)到500:1 。 在渦輪蝸桿組中由于蝸桿的的螺旋角很大，齒間滑動(dòng)可能是很大的，以及由此產(chǎn)生的摩擦損失驅(qū)動(dòng)器的效率通常要少百分之九十以上，有時(shí)甚至不到百分之五十，這遠(yuǎn)少于其它類型的齒輪。4.6齒輪齒條圖5齒輪齒條機(jī)架是齒列或棒，可以將其視為部分齒輪與無限大的曲率半徑。齒條與小齒輪扭矩可轉(zhuǎn)換為線性力，機(jī)架移動(dòng)直線。這種機(jī)制常被用于汽車轉(zhuǎn)換向的方向盤以及左向右運(yùn)動(dòng)的拉桿上 。支架還具有理論的齒輪幾何。例如，齒形的齒輪可相當(dāng)于一個(gè)機(jī)架（無限半徑）和一個(gè)具有標(biāo)準(zhǔn)齒的齒輪。齒輪齒條式的齒輪受制于齒條。5.齒輪的歷史據(jù)史料記載，遠(yuǎn)在公元前400200年的中國古代就巳開始使用齒輪，在我國山西出土的青銅齒輪是迄今巳發(fā)現(xiàn)的最古老齒輪，作為反映古代科學(xué)技術(shù)成就的指南車就是以齒輪機(jī)構(gòu)為核心的機(jī)械裝置。17世紀(jì)末，人們才開始研究，能正確傳遞運(yùn)動(dòng)的輪齒形狀。18世紀(jì)，歐洲工業(yè)革命以后，齒輪傳動(dòng)的應(yīng)用日益廣泛；先是發(fā)展擺線齒輪，而后是漸開線齒輪，一直到20世紀(jì)初，漸開線齒輪已在應(yīng)用中占了優(yōu)勢(shì)。早在1694年，法國學(xué)者Philippe De La Hire首先提出漸開線可作為齒形曲線。1733年，法國人M.Camus提出輪齒接觸點(diǎn)的公法線必須通過中心連線上的節(jié)點(diǎn)。一條輔助瞬心線分別沿大輪和小輪的瞬心線(節(jié)圓)純滾動(dòng)時(shí)，與輔助瞬心線固聯(lián)的輔助齒形在大輪和小輪上所包絡(luò)形成的兩齒廓曲線是彼此共軛的，這就是Camus定理。它考慮了兩齒面的嚙合狀態(tài)；明確建立了現(xiàn)代關(guān)于接觸點(diǎn)軌跡的概念。1765年，瑞士的LEuler提出漸開線齒形解析研究的數(shù)學(xué)基礎(chǔ)，闡明了相嚙合的一對(duì)齒輪，其齒形曲線的曲率半徑和曲率中心位置的關(guān)系。后來，Savary進(jìn)一步完成這一方法，成為現(xiàn)在的Eu-let-Savary方程。對(duì)漸開線齒形應(yīng)用作出貢獻(xiàn)的是Roteft WUlls，他提出中心距變化時(shí)，漸開線齒輪具有角速比不變的優(yōu)點(diǎn)。1873年，德國工程師Hoppe提出，對(duì)不同齒數(shù)的齒輪在壓力角改變時(shí)的漸開線齒形，從而奠定了現(xiàn)代變位齒輪的思想基礎(chǔ)。19世紀(jì)末，展成切齒法的原理及利用此原理切齒的專用機(jī)床與刀具的相繼出現(xiàn)，使齒輪加工具軍較完備的手段后，漸開線齒形更顯示出巨大的優(yōu)走性。切齒時(shí)只要將切齒工具從正常的嚙合位置稍加移動(dòng)，就能用標(biāo)準(zhǔn)刀具在機(jī)床上切出相應(yīng)的變位齒輪。1908年，瑞士MAAG研究了變位方法并制造出展成加工插齒機(jī)，后來，英國BSS、美國AGMA、德國DIN相繼對(duì)齒輪變位提出了多種計(jì)算方法。為了提高動(dòng)力傳動(dòng)齒輪的使用壽命并減小其尺寸，除從材料，熱處理及結(jié)構(gòu)等方面改進(jìn)外，圓弧齒形的齒輪獲得了發(fā)展。1907年，英國人Frank Humphris最早發(fā)表了圓弧齒形。1926年，瑞土人Eruest Wildhaber取得法面圓弧齒形斜齒輪的專利權(quán)。1955年，蘇聯(lián)的MLNovikov完成了圓弧齒形齒輪的實(shí)用研究并獲得列寧勛章。1970年，英國RolhRoyce公司工程師RM.Studer取得了雙圓弧齒輪的美國專利。這種齒輪現(xiàn)已日益為人們所重視，在生產(chǎn)中發(fā)揮了顯著效益。齒輪是能互相嚙合的有齒的機(jī)械零件，它在機(jī)械傳動(dòng)及整個(gè)機(jī)械領(lǐng)域中的應(yīng)用極其廣泛?，F(xiàn)代齒輪技術(shù)已達(dá)到：齒輪模數(shù)O.004100毫米；齒輪直徑由1毫米150米；傳遞功率可達(dá) 十萬千瓦；轉(zhuǎn)速可達(dá) 十萬轉(zhuǎn)/分；最高的圓周速度達(dá)300米/秒。齒輪在傳動(dòng)中的應(yīng)用很早就出現(xiàn)了。公元前三百多年，古希臘哲學(xué)家亞里士多德在機(jī)械問題中，就闡述了用青銅或鑄鐵齒輪傳遞旋轉(zhuǎn)運(yùn)動(dòng)的問題。中國古代發(fā)明的指南車中已應(yīng)用了整套的輪系。不過，古代的齒輪是用木料制造或用金 屬鑄成的，只能傳遞軸間的回轉(zhuǎn)運(yùn)動(dòng)，不能保證傳動(dòng)的平穩(wěn)性，齒輪的承載能力也很小。9AxleTrain wheels are affixed to a straight axle, such that both wheels rotate in unison. This is called a wheelset.An axle is a central shaft for a rotating wheel or gear. In some cases the axle may be fixed in position with a bearing or bushing sitting inside the hole in the wheel or gear to allow the wheel or gear to rotate around the axle. In other cases the wheel or gear may be fixed to the axle, with bearings or bushings provided at the mounting points where the axle is supported. Sometimes, especially on bicycles, the latter type is referred to as a spindle.Axles are an integral structural component of a wheeled vehicle. The axles maintain the position of the wheels relative to each other and to the vehicle body. Since for most vehicles the wheels are the only part touching the ground, the axles must bear the weight of the vehicle plus any cargo, as well as acceleration and braking forces. In addition to the structural purpose, axles may serve one or more of the following purposes depending on the design of the vehicle.Drive: One or more axles may be an integral part of the drivetrain. A mechanical system (typically a motor) exerts a rotational force on the axle, which is transferred to the wheel(s) to accelerate the vehicle. Braking: Conversely a vehicle may be slowed by applying force to brake the rotation of the axle. Consumer vehicles brakes are part of the wheel assembly and therefore exert friction on the wheels directly, but engine braking may still be effected via the axle. Steering: The front axle of most automobiles is a steering axle. The vehicle is maneuvered by controlling the direction of the front wheels rotational axis relative to the body and rear wheels. Structural features0 Series Shinkansen WheelA straight axle is a single rigid shaft connecting a wheel on the left side of the vehicle to a wheel on the right side. The axis of rotation fixed by the axle is common to both wheels. Such a design can keep the wheel positions steady under heavy stress, and can therefore support heavy loads. Straight axles are used on trains, for the rear axles of commercial trucks, and on heavy duty off-road vehicles. The axle can be protected and further reinforced by enclosing the length of the axle in a housing.In split-axle designs, the wheel on each side is attached to a separate shaft. Modern passenger cars have split drive axles. In some designs, this allows independent suspension of the left and right wheels, and therefore a smoother ride. Even when the suspension is not independent, split axles permit the use of a differential, allowing the left and right drive wheels to be driven at different speeds as the automobile turns, improving traction and extending tire life.A tandem axle is a group of two or more axles situated close together. Trucks designs will use such a configuration to provide a greater weight capacity than a single axle. Semi trailers usually have a tandem axle at the rear.Drive axlesSplines on a front drive axle.An axle that is driven by the engine is called a drive axle.Modern front wheel drive cars typically combine the transmission and front axle into a single unit called a transaxle. The drive axle is a split axle with a differential and universal joints between the two half axles. Each half axle connects to the wheel by use of a constant velocity (CV) joint which allows the wheel assembly to move freely vertically as well as to pivot when making turns.In rear wheel drive cars and trucks, the engine turns a driveshaft which transmits rotational force to a drive axle at the rear of the vehicle. The drive axle may be a live axle, but modern automobiles generally use a split axle with a differential.Some simple vehicle designs, such as go-karts, may have a single drive wheel. The drive axle is a split axle with only one of the two shafts driven by the engine.Dead axles/lazy axlesThis dump truck has an airlift pusher axle, shown in the raised position.A dead axle, also called lazy axle, is not part of the drivetrain but is instead free-rotating. The rear axle of a front-wheel drive car may be considered a dead axle. Many trucks and trailers use dead axles for strictly load-bearing purposes. A dead axle located immediately in front of a drive axle is called a pusher axle. A tag axle is a dead axle situated behind a drive axle.Some dump trucks and trailers are configured with airlift axles, which may be mechanically raised or lowered. The axle is lowered to increase the weight capacity, or to distribute the weight of the cargo over more wheels, for example to cross a weight restricted bridge. When not needed, the axle is lifted off the ground, to save wear on the tires and axle and increase traction in the remaining wheels. Lifting an axle also makes the vehicle perform better on tighter turns.Several manufacturers offer computer-controlled airlift, so that the dead axles are automatically lowered when the main axle reaches its weight limit. The axles can still be lifted by the press of a button if needed.GearOld clock with exposed gears.modern single-stage planetary gearhead for use with small fractional horsepower motorA gear is a component within a transmission device that transmits rotational torque by applying a force to the teeth of another gear or device. A gear is different from a pulley in that a gear is a round wheel that has linkages (teeth or cogs) that mesh with other gear teeth, allowing force to be fully transferred without slippage. Depending on their construction and arrangement, geared devices can transmit forces at different speeds, torques, or in a different direction, from the power source.The most common situation is for a gear to mesh with another gear, but a gear can mesh with any device having compatible teeth, such as linear moving racks.The gears most important feature is that gears of unequal sizes (diameters) can be combined to produce a mechanical advantage, so that the rotational speed and torque of the second gear are different from those of the first. In the context of a particular machine, the term gear also refers to one particular arrangement of gears among other arrangements (such as first gear). Such arrangements are often given as a ratio, using the number of teeth or gear diameter as units.Mechanical advantageIntermeshing gears in motionThe interlocking of the teeth in a pair of meshing gears means that their circumferences necessarily move at the same rate of linear motion (eg., metres per second, or feet per minute). Since rotational speed (eg. measured in revolutions per second, revolutions per minute, or radians per second) is proportional to a wheels circumferential speed divided by its radius, we see that the larger the radius of a gear, the slower will be its rotational speed, when meshed with a gear of given size and speed. The same conclusion can also be reached by a different analytical process: counting teeth. Since the teeth of two meshing gears are locked in a one to one correspondence, when all of the teeth of the smaller gear have passed the point where the gears meet - ie., when the smaller gear has made one revolution - not all of the teeth of the larger gear will have passed that point - the larger gear will have made less than one revolution. The smaller gear makes more revolutions in a given period of time; it turns faster. The speed ratio is simply the reciprocal ratio of the numbers of teeth on the two gears.(Speed A * Number of teeth A) = (Speed B * Number of teeth B)This ratio is known as the gear ratio. The torque ratio can be determined by considering the force that a tooth of one gear exerts on a tooth of the other gear. Consider two teeth in contact at a point on the line joining the shaft axes of the two gears. In general, the force will have both a radial and a tangential component. The radial component can be ignored: it merely causes a sideways push on the shaft and does not contribute to turning. The tangential component causes turning. The torque is equal to the tangential component of the force times radius. Thus we see that the larger gear experiences greater torque; the smaller gear less. The torque ratio is equal to the ratio of the radii. This is exactly the inverse of the case with the velocity ratio. Higher torque implies lower velocity and vice versa. The fact that the torque ratio is the inverse of the velocity ratio could also be inferred from the law of conservation of energy. Here we have been neglecting the effect of friction on the torque ratio. The velocity ratio is truly given by the tooth or size ratio, but friction will cause the torque ratio to be actually somewhat less than the inverse of the velocity ratio.In the above discussion we have made mention of the gear radius. Since a gear is not a proper circle but a roughened circle, it does not have a radius. However, in a pair of meshing gears, each may be considered to have an effective radius, called the pitch radius, the pitch radii being such that smooth wheels of those radii would produce the same velocity ratio that the gears actually produce. The pitch radius can be considered sort of an average radius of the gear, somewhere between the outside radius of the gear and the radius at the base of the teeth.The issue of pitch radius brings up the fact that the point on a gear tooth where it makes contact with a tooth on the mating gear varies during the time the pair of teeth are engaged; also the direction of force may vary. As a result, the velocity ratio (and torque ratio) is not, actually, in general, constant, if one considers the situation in detail, over the course of the period of engagement of a single pair of teeth. The velocity and torque ratios given at the beginning of this section are valid only in bulk - as long-term averages; the values at some particular position of the teeth may be different.It is in fact possible to choose tooth shapes that will result in the velocity ratio also being absolutely constant - in the short term as well as the long term. In good quality gears this is usually done, since velocity ratio fluctuations cause undue vibration, and put additional stress on the teeth, which can cause tooth breakage under heavy loads at high speed. Constant velocity ratio may also be desirable for precision in instrumentation gearing, clocks and watches. The involute tooth shape is one that results in a constant velocity ratio, and is the most commonly used of such shapes today.Comparison with other drive mechanismsThe definite velocity ratio which results from having teeth gives gears an advantage over other drives (such as traction drives and V-belts) in precision machines such as watches that depend upon an exact velocity ratio. In cases where driver and follower are in close proximity gears also have an advantage over other drives in the reduced number of parts required; the downside is that gears are more expensive to manufacture and their lubrication requirements may impose a higher operating cost.The automobile transmission allows selection between gears to give various mechanical advantages.Gear typesExternal vs. internal gearsUnlike most gears, an internal gear (shown here) does not cause direction reversal.An external gear is one with the teeth formed on the outer surface of a cylinder or cone. Conversely, an internal gear is one with the teeth formed on the inner surface of a cylinder or cone. For bevel gears, an internal gear is one with the pitch angle exceeding 90 degrees.Spur gearsSpur gears are the simplest and most common type of gear. Their general form is a cylinder or disk. The teeth project radially, and with these straight-cut gears, the leading edges of the teeth are aligned parallel to the axis of rotation. These gears can be meshed together correctly only if they are fitted to parallel axles.Helical gearsHelical gears from a Meccano construction set.Helical gears offer a refinement over spur gears. The leading edges of the teeth are not parallel to the axis of rotation, but are set at an angle. Since the gear is curved, this angling causes the tooth shape to be a segment of a helix. The angled teeth engage more gradually than do spur gear teeth. This causes helical gears to run more smoothly and quietly than spur gears.Helical gears also offer the possibility of using non-parallel shafts. A pair of helical gears can be meshed in two ways: with shafts oriented at either the sum or the difference of the helix angles of the gears. These configurations are referred to as parallel or crossed, respectively. The parallel configuration is the more mechanically sound. In it, the helices of a pair of meshing teeth meet at a common tangent, and the contact between the tooth surfaces will, generally, be a curve extending some distance across their face widths. In the crossed configuration, the helices do not meet tangentially, and only point contact is achieved between tooth surfaces. Because of the small area of contact, crossed helical gears can only be used with light loads.Hypoid gearsHypoid gears resemble spiral bevel gears, except that the shaft axes are offset, not intersecting. The pitch surfaces appear conical but, to compensate for the offset shaft, are in fact hyperboloids of revolution.Hypoid gears are almost always designed to operate with shafts at 90 degrees. Depending on which side the shaft is offset to, relative to the angling of the teeth, contact between hypoid gear teeth may be even smoother and more gradual than with spiral bevel gear teeth. Also, the pinion can be designed with fewer teeth than a spiral bevel pinion, with the result that gear ratios of 60:1 and higher are entirely feasible using a single set of hypoid gears.A worm is a gear that resembles a screw. It is a species of helical gear, but its helix angle is usually somewhat large (ie., somewhat close to 90 degrees) and its body is usually fairly long in the axial direction; and it is these attributes which give it its screw like qualities. A worm is usually meshed with an ordinary looking, disk-shaped gear, which is called the gear, the wheel, the worm gear, or the worm wheel. The prime feature of a worm-and-gear set is that it allows the attainment of a high gear ratio with few parts, in a small space. Helical gears are, in practice, limited to gear ratios of less than 10:1; worm gear sets commonly have gear ratios between 10:1 and 100:1, and occasionally 500:1.In worm-and-gear sets, where the worms helix angle is large, the sliding action between teeth can be considerable, and the resulting frictional loss causes the efficiency of the drive to be usually less than 90 percent, sometimes less than 50 percent, which is far less than other types of gears.Rack and pinion A rack is a toothed bar or rod that can be thought of as a sector gear with an infinitely large radius of curvature. Torque can be converted to linear force by meshing a rack with a pinion: the pinion turns; the rack moves in a straight line. Such a mechanism is used in automobiles to convert the rotation of the steering wheel into the left-to-right motion of the tie rod(s). Racks also feature in the theory of gear geometry, where, for instance, the tooth shape of an interchangeable set of gears may be specified for the rack (infinite radius), and the tooth shapes for gears of particular actual radii then derived from that. The rack and pinion gear type is employed in a rack railway.According to historical records, far from 400 BC to 200 years in ancient China has been started on the use of gears, unearthed in Shanxi Province in Chinas bronze gear have been found so far the oldest of the gear, as reflected in scientific and technological achievements of ancient cart is gearing mechanical devices at the core. End of the 17th century, people began to study transmission of movement to correct the shape of the tooth. The 18th century, the European industrial revolution, the gear drives the application of the increasingly widespread; first cycloid gear development, and the latter is the involute gear until the early 20th century, involute gear has been accounted for in the application of the advantage.As early as 1694, the French scholar Philippe De La Hire first involute curve can be used as profile. In 1733, the French made M. Camus tooth contact point of the law center line connection through the node. Instantaneous center line of a supporting, respectively, along the large round and small roundThe instantaneous center line (pitch) of pure rolling, the instantaneous center line and auxiliary aids together solid profile in the round and round on the small envelope formed by the two tooth profile curve is conjugate to each other, and this is the theorem Camus. It takes a two-tooth meshing state; clearly established the modern trajectory of contact point onAccording to historical records, far from 400 BC to 200 years in ancient China has been started on the use of gears, unearthed in Shanxi Province in Chinas bronze gear have been found so far the oldest of the gear, as reflected in scientific and technological achievements of ancient cart is gearing mechanical devices at the core. End of the 17th century, people began to study transmission of movement to correct the shape of the tooth. The 18th century, the European industrial revolution, the gear drives the application of the increasingly widespread; first cycloid gear development, and the latter is the involute gear until the early 20th century, involute gear has been accounted for in the application of the advantage.The late 19th century, show the principle of law into gear and use the principle of exclusive Cutting Machine Tool and Tool have emerged one after another, so that gear plus a more comprehensive tool for the military means, the involute profile of a great show of excellent walking. Just when Cutting Cutting Tools from the normal location of the mesh a little mobile, you can use the standard tool in machine cut gear shift accordingly. 1908, Switzerland MAAG variable method to study and create a show into gear processing machine, subsequently, the United Kingdom BSS, the United States AGMA, the German DIN have to shift gears to a variety of calculation methods.In order to improve the power transmission gear life and reduce its size, with the exception from the material, heat treatment and to improve the structure, the arc of the gear tooth development was. In 1907, the British released the first Frank Humphris arc tooth profile. In 1926, Swiss natives of Laws Eruest Wildhaber helical gear tooth surface arc of the franchise. In 1955, the Soviet Union, M. L. Novikov gear tooth to complete the arc of the applied research and the Order of Lenin. In 1970, the British company Rolh-Royce engineer R. M. Studer made a double circular gear U.S. patents. This gear has been a growing importance for the people,Gear is meshing with each other tooth of the mechanical parts, which in mechanical transmission and the machinery in the field of a wide range of applications. Modern technology has reached Gear: Gear modulus O.004 100 mm; gear diameter by 1 mm 150 meters; transmission power up to 100,000 kilowatts; speed of up to 100,000 rev / min; the highest speeds of up to 300 meters circumference / seconds.Gear in the transmission of applications have emerged very early on. 300 years BC, the ancient Greek philosopher Aristotle in the mechanical problems, in relation to the use of cast iron bronze gear transmission or the issue of rotation. Guide to the ancient Chinese invented the car has been applied a comprehensive set of gear. However, the ancient wood of the gear is used to manufacture or use of cast metal and can only pass between the rotary axis mov