雙離合自動(dòng)變速器的七檔齒輪變速器設(shè)計(jì),雙離合自動(dòng)變速器的七檔齒輪變速器設(shè)計(jì),離合,自動(dòng)變速器,齒輪,變速器,設(shè)計(jì) 哈工大華德學(xué)院畢業(yè)設(shè)計(jì)（論文）任務(wù)書(shū) 姓 名： 董偉 院 （系）：汽車(chē)工程系 專(zhuān) 業(yè)：汽車(chē)車(chē)輛工程工程 班 號(hào)：0893112 任務(wù)起至日期： 2011年 10月 11日至2011年 12月 28日 畢業(yè)設(shè)計(jì)（論文）題目： 雙離合自動(dòng)變速器的七檔齒輪變數(shù)器設(shè)計(jì) 立題的目的和意義： 雙離合器式自動(dòng)變速器（DualClutehTransmission，即DCT），是由雙軸式手動(dòng)變速器發(fā)展而來(lái)的。他即保留了結(jié)構(gòu)簡(jiǎn)單、傳動(dòng)效率高的優(yōu)點(diǎn)，又具有電液控制方式的優(yōu)點(diǎn)，改善了換擋品質(zhì)，降低了油耗、故障率和制造成本。目前國(guó)內(nèi)外有許多汽車(chē)大公司與學(xué)者在致力于雙離合式自動(dòng)變速器的開(kāi)發(fā)與研究，并已在多款車(chē)上應(yīng)用。因此研究雙離合自動(dòng)變速器的工作特性，并對(duì)其齒輪變速器進(jìn)行設(shè)計(jì)，是非常重要和必須的。 本課題的選擇充分考慮了研究課題對(duì)汽車(chē)專(zhuān)業(yè)學(xué)生學(xué)習(xí)和工作的指導(dǎo)作用，對(duì)本課題的研究能夠使學(xué)生了解汽車(chē)總成部件的設(shè)計(jì)方法，通過(guò)本課題的研究學(xué)生可以完成專(zhuān)業(yè)課程的實(shí)踐總結(jié)，獲得一定的工程設(shè)計(jì)工作方法。 技術(shù)要求與主要內(nèi)容： （1） 發(fā)動(dòng)機(jī)最大轉(zhuǎn)矩（Nm/rpm）：250/5000；發(fā)動(dòng)機(jī)最大功率（Kw/rpm）:200/6200; 輪胎類(lèi)型與規(guī)格：245/40R18;汽車(chē)最高車(chē)速：250Km/h; 前軸負(fù)荷：8000N； 后軸負(fù)荷：7000N 輪胎氣壓：2.5MPa；轉(zhuǎn)向盤(pán)操縱力：不超過(guò)200N； （2） 設(shè)計(jì)方法與設(shè)計(jì)過(guò)程參照汽車(chē)設(shè)計(jì)變速器設(shè)計(jì)規(guī)定進(jìn)行。 （3） 要求研究汽車(chē)汽車(chē)設(shè)計(jì)、機(jī)械制圖、機(jī)械設(shè)計(jì)、材料力學(xué)等相關(guān)知識(shí)，并將這些知識(shí)有機(jī)結(jié)合、熟練運(yùn)用； （4） 要求對(duì)雙離合器式自動(dòng)變速器的七檔齒輪變速器進(jìn)行主要參數(shù)的選擇與設(shè)計(jì)計(jì)算，工藝合理、成本低、可靠性高； （5） 用AutoCAD完成裝配圖、零件圖，設(shè)計(jì)表達(dá)設(shè)計(jì) 一、其中主要的設(shè)計(jì)內(nèi)容有： 1. 變速器主要參數(shù)的選擇 2. 變速器齒輪參數(shù)的確定 3. 變速器結(jié)構(gòu)元件的設(shè)計(jì) 4. 齒輪的強(qiáng)度計(jì)算及校核、軸的計(jì)算和校核以及其他零部件的強(qiáng)度計(jì)算及校核， 最后進(jìn)行變速器整體的性能分析，在對(duì)各種結(jié)構(gòu)件進(jìn)行了分析計(jì)算后，繪制變速器的整體裝配圖及各主要零部件的零件圖。 二、論文要求 1.參考文獻(xiàn)篇數(shù)：10篇以上（其中不少于2篇外文文獻(xiàn)） 2.內(nèi)容充實(shí)，結(jié)構(gòu)清晰合理，符合規(guī)范 3.必須進(jìn)行大量的實(shí)地調(diào)查 4.撰寫(xiě)設(shè)計(jì)說(shuō)明書(shū)15000字以上。 三、設(shè)計(jì)（論文）完成后應(yīng)提交的成果 進(jìn)度安排： 第1-2周：選題，進(jìn)行調(diào)研，收集資料，完成開(kāi)題報(bào)告。 第3周：研究結(jié)構(gòu)原理、設(shè)計(jì)步驟與設(shè)計(jì)方法，確定總體方案。 第4-7周：主要參數(shù)的選擇與設(shè)計(jì)計(jì)算。 第8-10周：完成所設(shè)計(jì)裝配圖與零件圖圖紙。 第11周：完成設(shè)計(jì)修改;整理完成設(shè)計(jì)說(shuō)明書(shū)，結(jié)題。 第12周：準(zhǔn)備答辯 指導(dǎo)教師簽字___________________ 年 月 日 系（教研室）主任意見(jiàn)： 系（教研室）主任簽字___________________ 年 月 日 哈爾濱工業(yè)大學(xué)華德應(yīng)用技術(shù)學(xué)院 畢業(yè)設(shè)計(jì)（論文） 題 目 雙離合器自動(dòng)變速器的 七檔齒輪變速器設(shè)計(jì) 專(zhuān) 業(yè) 車(chē)輛工程 學(xué)　　 號(hào) 1089311224 學(xué) 生 董偉 指 導(dǎo) 教 師 趙雨旸 　　 答 辯 日 期 　　　 哈爾濱華德學(xué)院 畢業(yè)論文開(kāi)題報(bào)告 學(xué)生姓名 董偉 系部 汽車(chē)工程系 專(zhuān)業(yè)、班級(jí) 車(chē)輛工程08-2班 指導(dǎo)教師姓名 趙雨旸 職稱 副教授 從事 專(zhuān)業(yè) 車(chē)輛工程 是否外聘 ■是□否 題目名稱 雙離合器自動(dòng)變速器的七檔齒輪變速器設(shè)計(jì) 一、論文的目 的、意義及研究發(fā)展方向 1、課題研究的目的、意義 傳統(tǒng)的汽車(chē)自動(dòng)變速器主要有液力機(jī)械式自動(dòng)變速器（AT）、無(wú)級(jí)自動(dòng)變速器（CVT）以及近幾年開(kāi)發(fā)的電控機(jī)械式自動(dòng)變速器（AMT）。AT具有較好的駕駛舒適性，操作簡(jiǎn)單，技術(shù)成熟，但結(jié)構(gòu)復(fù)雜、成本高、傳動(dòng)效率低、油耗較高;CVT具有良好的操作性、駕駛舒適性和較高的傳動(dòng)效率，但成本也較高，且目前只適用于小排量轎車(chē)；AMT是通過(guò)在手動(dòng)變速器上加裝計(jì)算機(jī)控制的操縱系統(tǒng)來(lái)實(shí)現(xiàn)自動(dòng)變速控制具有機(jī)構(gòu)簡(jiǎn)單、效率高、成本低等特點(diǎn)，使用手動(dòng)變速器實(shí)現(xiàn)自動(dòng)換擋成為可能。但換擋時(shí)要切斷動(dòng)力（分離離合器），在動(dòng)力切斷和再次接合時(shí)必然引起傳動(dòng)系統(tǒng)沖擊，同時(shí)動(dòng)力切斷過(guò)程也造成了動(dòng)力損失，影響了車(chē)輛的乘坐舒適性和動(dòng)力性，目前只能在低檔轎車(chē)和重型車(chē)輛上應(yīng)用。 為從根本上解決AMT切斷動(dòng)力換擋帶來(lái)的問(wèn)題，近年來(lái)出現(xiàn)了一種雙離合器式自動(dòng)變速器(DCT)，DCT是基于平行軸手動(dòng)變速器發(fā)展而來(lái)，它繼承了手動(dòng)變速器傳動(dòng)效率高、安裝空間緊湊、質(zhì)量輕、價(jià)格低等許多優(yōu)點(diǎn)，而且實(shí)現(xiàn)了動(dòng)力換擋，這不僅保證了車(chē)輛的加速性，而且由于車(chē)輛不再產(chǎn)生由于換擋引起的急劇減速情況，也極大地改善了車(chē)輛運(yùn)行的舒適性。所以我設(shè)計(jì)一款雙離合器自動(dòng)變速器的七檔齒輪變速器。 DCT在推廣使用方面的一個(gè)顯著的優(yōu)點(diǎn)是它幾乎不受傳遞功率的限制，應(yīng)用范圍廣，它既可以應(yīng)用在大型載重汽車(chē)、城市公共汽車(chē)、工程機(jī)械、中型貨車(chē)等大中型車(chē)輛上，使駕駛員免于頻繁的換擋操作，而且由于它的換擋時(shí)間很短，也可以應(yīng)用在運(yùn)動(dòng)型車(chē)輛上。通常在功率較大的車(chē)輛中，它的應(yīng)用更為有利。這是因?yàn)?，一般情況下它有兩根傳動(dòng)軸是同心的，即中間的一根傳動(dòng)軸是實(shí)心的，而套在他外面的則是一根空心的，由于軸的剛度、強(qiáng)度以及結(jié)構(gòu)尺寸等方面的原因，較大的傳動(dòng)軸軸徑有利于雙離合自動(dòng)變速器的設(shè)計(jì)，多適合功率較大的車(chē)輛，對(duì)于小功率車(chē)輛，如果要開(kāi)發(fā)設(shè)計(jì)雙離合器式自動(dòng)變速器，也可以采用雙中間軸的布置方案。這種方案不再采用軸套的方式，而是采用了兩個(gè)獨(dú)立的中間軸，其剛度和強(qiáng)度都不再有問(wèn)題，而且這樣設(shè)計(jì)的雙離合器式自動(dòng)變速器軸向尺寸非常緊湊。 DCT在推廣使用方面的另一個(gè)顯著的優(yōu)點(diǎn)生產(chǎn)成本低。它是靠離合器和齒輪傳遞動(dòng)力的，復(fù)雜程度低，對(duì)現(xiàn)有的手動(dòng)擋變速器生產(chǎn)線稍加改造就可以轉(zhuǎn)而生產(chǎn)DCT，充分利用原有手動(dòng)變速器生產(chǎn)設(shè)備，生產(chǎn)廠將產(chǎn)品升級(jí)到自動(dòng)變速器。 2、課題研究發(fā)展方向 DCT的動(dòng)力傳遞通過(guò)兩個(gè)離合器聯(lián)接兩根輸入軸,相鄰各檔的被動(dòng)齒輪交錯(cuò)與兩輸入軸齒輪技術(shù)導(dǎo)向嚙合,配合兩離合器的控制,能夠?qū)崿F(xiàn)在不切斷動(dòng)力的情況下轉(zhuǎn)換傳動(dòng)比,從而縮短換檔時(shí)間,有效提高換檔品質(zhì)。DCT既繼承了手動(dòng)變速器傳動(dòng)效率高、安裝空間緊湊、重量輕、價(jià)格便宜等許多優(yōu)點(diǎn),而且實(shí)現(xiàn)了換檔過(guò)程的動(dòng)力換檔,即在換檔過(guò)程中不中斷動(dòng)力,這不僅對(duì)AMT來(lái)說(shuō)是一個(gè)巨大的進(jìn)步,而且還保留了AT、CVT等換檔品質(zhì)好的優(yōu)點(diǎn),因此是自動(dòng)變速器的發(fā)展方向。 3、課題國(guó)外的研究狀況 1940年,Darmstadt大學(xué)教授RudolphFranke第一個(gè)申請(qǐng)了DCT專(zhuān)利,隨后保時(shí)捷也發(fā)明了專(zhuān)用于賽車(chē)的雙離合變速器(PDK)。然而,在那個(gè)時(shí)代,未能成功將DCT/PDK技術(shù)投入批量生產(chǎn)。到了20世紀(jì)90年代末期,大眾公司和博格華納攜手合作生產(chǎn)第一個(gè)適用于大批量生產(chǎn)和應(yīng)用于主流車(chē)型的DCT。2002年,DCT應(yīng)用在德國(guó)大眾高爾夫R32和奧迪TTV6上。2003年,其相繼推廣到高爾夫等其他車(chē)型上。2004年,DCT在德國(guó)大眾途安車(chē)型上首次與TDI柴油發(fā)動(dòng)機(jī)匹配。到2006年,搭載DCT的大眾車(chē)型累計(jì)達(dá)到70萬(wàn)輛。2007年,法拉利、雷諾等公司紛紛推出了各自的賽車(chē),一個(gè)共同的特點(diǎn)是全都搭載了類(lèi)似DCT的變速器。同時(shí),Recardo公司開(kāi)發(fā)出了DCT樣機(jī),并裝備在Bugatti-Veyron跑車(chē)上。LuK公司與Ford、Getrag公司合作,共同開(kāi)發(fā)帶有干式離合器的DCT,稱為平行軸式變速器(PSG)。目前的DCT車(chē)型多為扭矩在350Nm左右的中級(jí)車(chē),現(xiàn)在正準(zhǔn)備向扭矩在150Nm左右的小型車(chē)發(fā)展。日本一家小型車(chē)巨頭已經(jīng)確定引入DCT,不久將會(huì)有DCT版的小型車(chē)批量推向市場(chǎng)。 4、課題國(guó)內(nèi)的研究狀況 目前，國(guó)內(nèi)DCT項(xiàng)目模式為中發(fā)聯(lián)提供DCT核心模塊，國(guó)內(nèi)整車(chē)廠自己生產(chǎn)箱體和總成。由于各個(gè)成員間開(kāi)發(fā)實(shí)力以及條件的原因，DCT二次合資并未成功。其中，一汽在長(zhǎng)春的DCT總成合資公司預(yù)計(jì)2011年底投產(chǎn)；上汽則在吉孚的幫助下自行開(kāi)發(fā)DCT總成；長(zhǎng)安、江淮將組團(tuán)開(kāi)發(fā)總成的研發(fā)成果和生產(chǎn)線；合資后的廣汽將利用杭州IVECO生產(chǎn)DCT總成；手握DSI的吉利也具備了研制和制造總成的能力；奇瑞將利用自建的總成生產(chǎn)線以及來(lái)自于DSI的變速器技術(shù)人員來(lái)開(kāi)發(fā)DCT總成；華晨和長(zhǎng)城則計(jì)劃從上汽或一汽采購(gòu)總成?！岸魏腺Y”的失敗在一定層面上說(shuō)明國(guó)內(nèi)自主OEM在DCT產(chǎn)品上都急切想邁出市場(chǎng)“第一步”。國(guó)內(nèi)自主品牌也在同步進(jìn)行著DCT整機(jī)的實(shí)驗(yàn)開(kāi)發(fā)，并取得了相當(dāng)大的進(jìn)步和一些值得推崇的經(jīng)驗(yàn)，比如一汽、吉利、上汽以及江淮等等。 目前一汽的第一款DCT產(chǎn)品6DT-200的研發(fā)工作已經(jīng)完成，在重量、動(dòng)力性和燃油經(jīng)濟(jì)性方面具有明顯優(yōu)勢(shì)。 二、論文基本內(nèi)容 1、變速器總體概述 2、雙離合器式自動(dòng)變速器的七檔齒輪變速器變速器結(jié)構(gòu)方案分析 3、雙離合器式自動(dòng)變速器的七檔齒輪變速器主要參數(shù)確定 4、雙離合器式自動(dòng)變速器的七檔齒輪變速器主要參數(shù)的選擇與設(shè)計(jì)計(jì)算； 5、同步器的主要參數(shù)的確定 三、研究方法 1、本課題的技術(shù)路線如下圖 變速器主要參數(shù)選擇 變速器的基本設(shè)計(jì)方案 變速器軸的設(shè)計(jì)計(jì)算 變速器各檔齒輪的設(shè)計(jì)計(jì) 滾動(dòng)軸承選擇和計(jì)算 變速器齒輪的校核 變速器軸的校核 2、要解決的主要問(wèn)題和技術(shù)關(guān)鍵 1）、變速器的結(jié)構(gòu)型式及的選擇； 2）、變速器軸的結(jié)構(gòu)選擇； 3）、校核部件解決變速器的壽命問(wèn)題; 4）、設(shè)計(jì)方法與設(shè)計(jì)過(guò)程參照汽車(chē)設(shè)計(jì)變速器設(shè)計(jì)規(guī)定進(jìn)行。 5）、運(yùn)用汽車(chē)汽車(chē)設(shè)計(jì)、機(jī)械制圖、機(jī)械設(shè)計(jì)、材料力學(xué)等相關(guān)知識(shí)，并將這些知識(shí)有機(jī)結(jié)合、熟練運(yùn)用； 6）、工藝合理、成本低、可靠性高； 7)、用AutoCAD完成裝配圖、零件圖，設(shè)計(jì)表達(dá)設(shè)計(jì) 四、設(shè)計(jì)（論文）進(jìn)度安排 第1~2周：選題，進(jìn)行調(diào)研，收集資料，完成開(kāi)題報(bào)告。 第3周：研究結(jié)構(gòu)原理、設(shè)計(jì)步驟與設(shè)計(jì)方法，確定總體方案。 第4~7周：主要參數(shù)的選擇與設(shè)計(jì)計(jì)算。 第8~10周：完成所設(shè)計(jì)裝配圖與零件圖圖紙。 第11周：完成設(shè)計(jì)修改;整理完成設(shè)計(jì)說(shuō)明書(shū)，結(jié)題。 第12周：準(zhǔn)備答辯 五、主要參考資料 [1] 郭新華.汽車(chē)構(gòu)造.北京：高等教育出版社，2009.9，第二版 [2] 王望予.汽車(chē)設(shè)計(jì).北京：機(jī)械工業(yè)出版社，2004.8，第四版 [3] 劉惟信.汽車(chē)設(shè)計(jì).北京：清華大學(xué)出版社，2001.7，第一版 [4] 程燕平.理論力學(xué).哈爾濱：哈爾濱工業(yè)大學(xué)出版社，2008.7，第一版 [5] 王春香.基礎(chǔ)材料力學(xué).北京：科學(xué)出版社，2007.8，第一版 [6] 王黎欽.機(jī)械設(shè)計(jì).哈爾濱：哈爾濱工業(yè)大學(xué)，2008.8，第四版 [7] 劉品.李哲.機(jī)械精度設(shè)計(jì)與檢測(cè)基礎(chǔ).哈爾濱：哈爾濱工業(yè)出版社，2007.7，第五版 [8] 《汽車(chē)工程手冊(cè)》委員會(huì).汽車(chē)工程手冊(cè)——設(shè)計(jì)篇.人民交通出版社，2001.5，第一版 [9]ThomasC.Bowen,RochesterHills,ML(US).TwinClutchAutomatedTransmission.US,pub.No,:0088 289 A 1,2002 [10] Abdreas Hegerath,Bergheim(DE).Dual Clutch For A Transmission With Two Input Shafts. US, Patent NO:6929107B2.2005 [11] 李健 雙離合式自動(dòng)變速器換擋品質(zhì)研究[期刊論文]-客車(chē)技術(shù) 2009(5) [12] 荊崇波.苑士華.郭曉林 雙離合器自動(dòng)變速器及其應(yīng)用前景分析[期刊論文]-機(jī)械傳動(dòng) 2005 六、指導(dǎo)教師評(píng)語(yǔ) 指導(dǎo)教師簽字： 年 月 日 教研室主任簽字： 年 月 日 黑龍江工程學(xué)院本科生畢業(yè)設(shè)計(jì) 附　　錄 附錄A 外文文獻(xiàn)原文 7-Speed Dual Clutch Transmission System for Sporty Application ABSTRACT:With its 7-speed dual clutch transmission, ZF has introduced an innovative transmission for sporty applications. The close ratios combined with extremely spontaneous drive behavior makes it an ideal transmission for sporty applications. This article describes the compact gear set with lubrication by injection for improving the level of efficiency and increasing the engine-speed-strength, the dual clutch unit as well as the hydraulic control unit, which is based on the pre-control principle, are also described in detail. The hy-draulic control principle provides the option of a hydraulic cruise mode in the event of an electronics failure. In addition to the transmission design, functional features that also highlight the sporty character of the transmission are described in detail. Key words: Automatic transmission; Dual clutch; Vehicle connection; Efficiency 1 Introduction When it comes to the field of automatic transmissions, dual clutch systems currently represent the benchmark in terms of spontaneity and sportiness. In this type of transmission, which is based on a countershaft transmission, these advantages are combined with a very direct "vehicle connection", high rpm performance, and excellent transmission efficiency. The 7-speed dual clutch transmission for the standard driveline presented here is designed for a torque capacity of up to 520 Nm and rotational speeds of up to 9250 rpms. In order to be able to achieve these performance data in the existing installation space, a concept was developed in which an oil chamber as well as lubrication by injection are used. Before introducing the transmission′s several unique features in more detail below, an overview of the basic transmission design will be presented, Fig. 1.The engine torque is introduced to the dual clutch via a torsion damper (not shown in Fig. 1). The multidisk clutches in the dual clutch are radially nested in one another and transfer the torque to both input shafts in the countershaft transmission gear set. In this case, due to the installation space, the countershaft is not located under the main shaft, but is tilted laterally. This becomes possible because the concept is based on lubrication by injection with a dry sump. On the one hand, lubrication by injection improves heat removal, on the other, there are no noticeable losses due to the gears splashing in the oil pan. The oil is supplied to the transmission via an internal gear pump which is driven by a spur gear train behind the dual clutch. With the help of a spur gear train, the drive unit has the advantage that, via different gear ratio phases and depending on the intended use, the flow rate and the max. speed of the pump can be adapted. An additional advantage is that based on theresulting I proved installation space, an optimal ratio between the pump width and the pump diameter can be achieved for the pump′s level of efficiency. The hydraulic control unit is arranged under the gear set. The hydraulic unit supplies the clutch, based on need, with pressure and cooling oil as well as shift actuators. The latter are arranged laterally to the gear set and work with double-acting cylinders. The sensor for detecting the position of the gearshifts is attached directly onto the four gearshifts. The transmission has an external control unit. Fig.1　Overview dual clutch transmission (DCT) 2 Seven speeds with sophisticated stepping-a concept for extrme sporti- ness The gear set concept of the dual clutch transmission introduced here was developed in house taking into consideration the following requirements: High power density High speed endurance strength up to 9250 rpm Variability and modular design Representation of transmission-ratio spreads of about 4.7 and 6.8 with 7 speeds Use of existing synergies for manual transmissions After extensive systematic development of the gear set in which many thousands of variants were produced and compared, the gear set concept that is illustrated in Fig. 2 is the final variant and the ideal concept for achieving the goals specified. The gear set selected is based on the constant drive concept and consists of two concentric drive shafts each of which are driven by one of the two multidisk clutches in the Fig.2　Gear set scheme of 7D variant dual clutch, two countershafts also concentric to one another, a main shaft and an output shaft. The gear ratios are engaged by the four synchronizer units A/B, C/D, E/F, and G/H, which are arranged on the main shaft and on the hollow countershaft and these are connected to the loose wheels or the adjacent shafts. An important feature in the gear set is the connectability of both countershafts through the C/D synchronizer unit. In the D shift position, the gear ratios selected in this way can be doubly used which reduces construction costs compared to conventional dual clutch gear sets. Similarly, this feature is used in first gear because then the vehicle is started up using the more powerful K1 clutch. Because of this dual use of the last gear level in the transmission for the first and second gear, the desired ratio step 1-2 is achieved through the transmission ratios of both constant drive phases. The use of the K1 clutch for starting up in first gear results inevitably in the direct gear also being assigned to the odd subsection. In this case, the fifth and seventh gears can be selected as a direct drive. With this feature, it was possible to develop a modular gear set which, on just a few changes,contains two different transmission gear ratio variants with fundamentally different characters. For the first version, with an overall spread of about 4 . 7 , the seventh gear is selected as a direct gear (called the 7D variant). Fig. 2 shows the relevant gear set diagram with the performance flows in all speeds. Due to its sophisticated gear steps, this transmission is highly suitable for very sporty vehicles that need only a "little" transmission stepping due to the high rotating engine. Optimal tractive power can be provided at any time during vehicle operation. The second version is based on the 7D variant, however, fifth gear was selected as the direct drive. When maintaining the torque multiplication ratio and in adapting the transmission ratio of several lower gear levels, you get the 5D variant with a considerably higher transmission-ratio spread for vehicles with increased comfort demands and simultaneously reduced consumption. Fig. 3 illustrates the design of the 7D variant. The main similarity with existing manual transmissions for standard transmissions is noticeable. Due to the compact gear set design, the sufficient shaft dimensioning and the favorable arrangement in proximity of the bearing of the high transmitting ratios, central bearing glasses were not necessary despite the proportionally large bearing clearance.Overall, only two housing bearing levels are necessary where the front level is located behind both constant gears. In addition, a very compact and inexpensive transmission design could be implemented based on the bearing concept selected, especially in the area of the hollow shaft. Fig.3　Sectional Drawing of 7D variant 3 The dual clutch The central module of this highly topical transmission concept is the wet dual clutch. With a broad spectrum of technical features, it implements the functional provisions of the transmission control unit and thus distinguishes the special character of this transmission concept. Very fast delay times, low inertia and good, comfortable friction value progressions facilitate, very sporty handling with highly dynamic gear shifting and comfortable cruising at a high level of efficiency. The dual clutch placed directly on the transmission input accepts the engine torque from thtorsion damper and feeds it to one of the two subsections, depending on the situation. Safety considerations have led to a "normall open" design. The radial arrangement of the multidisk pack age represents the best combination of performanc and installation space need, Fig. 4. Fig.4　Dual clutch Careful lining and oil selection as well as intensive enhancement of this tribological system are the requirements for comfort and performance of this clutch throughout its service life. Through intense testing and detailed calculations, it was possible to achieve a very high therma loading capacity. As part of the process, the lining type, dimensioning, and grooving as well as equal distribution of thermal load and oil flow in the multidisk package are decisive design features. Low torque drag even with low temperatures as well as high speed endurance strength support comfort and a high level of sportiness, but are also important safety requirements. Rotating, centrifugal force-compensating clutch cylinders with hysteresis optimized gaskets make the clutches easy to control. Integrated plate springs reliably accept rapid piston resetting even at high speeds. In the case of an open clutch, only transmission input shafts with very low additional mass inertia are used. This supports rapid synchronizing sequences and a long service life of the synchronizer units. 4 The hydraulic control unit In the present dual clutch transmission, the hydraulic control unit fulfills the following tasks: Actuating the dual clutch Shifting the gearshifts, i. e. engaging/synchronizing the gear Cooling the dual clutch Gear lubrication Emergency stop function in case of complete failure of transmission electronics Several features in the hydraulic control unit as well as criteria for the selection of the control concept are going to be described in more detail below. 4.1 Performance The use of the dual clutch transmission in sporty vehicles demands high performance from the hydraulic control unit, especially with regard to the first two tasks because the timely "handling" of these tasks come into play in gear shifting and gear shifting times. That is why particular value is placed on the selection of the right control unit concept as part of the system design. During the decision process, the choice was made, in principle, between two concepts, Fig. 5. Fig.5　Control concept direct control / precontrol Precontrol of the valves Direct control of the valves (so-called cartridge valves) In case of direct control, the valve that is used for pressure control, e.g. a clutch, is directly connected to the power-generating proportional solenoids and provides the main pressure to the corresponding clutch pressure. The precontrol uses the pressure that is supplied by a pressure controller, for example, to actuate an additional valve that supplies the clutch pressure from the main pressure. To assess the performance of both concepts, a larger number of compared measurements were performed with different systems, of which two systems shall be considered here: ZF hydraulic control unit with precontrol for DCT standard drive Comparative hydraulic control unit with direct control A reference clutch was used as the clutch to engage. Criteria for assessing the performance were (see also Fig. 6): Fig.6　Delay, increase/rise, and fall times. Red curve: Power /Electric current. Green curve: Clutch pressure Delay time, 1 to 4 Time of step response until clutch inflation pressure, 1 to 2 Time of the step response up to 90% of the main pressure 1 to 3 Time of pressure drop (emptying times), 5 to 6 Fig. 6 shows, as an example, the times for a transmission oil temperature of + 20°C to be reached. One notices that the direct control first in dicates a lower delay time (14.3 ms) compared to the precontrol (30.1 ms), see also time of brand 1 to 4. For increase to clutch inflation pressure or to 90% of the main pressure　　shows, however, the advantage of the precontrolled system (see also summarizing tab 1). Emptying times, also present a disadvantage for direct control. Trans-mission oil temperature of -20°C also show comparable results for step responses and fall times. All of the tests support the statement that direct control has an advantageous effect with small oil volumes. However, if large oil volumes have to be transported, precontrol valves are to be preferred due to larger opening cross-sections. 4.2 Operational safety Operational safety is determined essentially due to the soiling tendency because the so-called silting can lead to the valves getting jammed. Provocation tests with transmission-specific environmental conditions (dirty oil) demonstrated the influences of soiling on the characteristic curves. Technical, trouble-free characteristic curve progressions could be illustrated only with a high dither amplitude in valve actuation, which leads, in turn, to increased valve wear-and-tear due to the micro movements that it causes. The increased tendency toward soiling can result needing a fine filter. 4.3 Costs In addition to the delay time comparison as well as assessing the operational safety, the costs were relevant for a final evaluation. The compari son with regard to the hydraulic and electro-mag netic components shows that a precontrol system has cost benefits compared to a direct control system. Added to this are the higher flows with the actuation of direct control valves, which, in turn, result in a more expensive TCU. Furthermore, in opting for precontrol, ZF is able to "pool" together pressure controllers in large quantities because these, too, are used in the automatic ZF planetary gear set. 4.4 Emergency stop function In case there is a complete outage in the transmission electronics, a hydraulic emergency stop function is actuated in the transmission. The clutch that is pressurized with a larger amount of pressure in the event of a system outage will continue to be pressurized. This condition is maintained until an adjustable engine speed threshold is achieved, then the clutch opens in order to prevent the engine from being choked. It is not possible to re-start this system. 5 Sporty functions For function developers, the dual clutch transmission offers the opportunity to combine the comfort of a stepped automatic transmission with the dynamics and sportiness of a countershaft transmission. Connected, therefore, are typical " catalog values," such as time from zero to 100 kilometers per hour or the time from 80 to 120 kilometers per hour with correspondingly fast kick-down shifting, but also subjective acceleration sensitivity during a shifting sequence where the purist among the manual transmission drivers still wants to feel that jolt of acceleration. One function especially designed for the dual clutch transmission in sports cars is the "race start"function. The race start is a function used to achieve optimal acceleration from a standstill, i.e. in the shortest time from 0 to 100 km/h. The sequence progresses as follows: The engine is brought to a suitably high rpm with the clutch engaged in first gear. The driver simultaneously actuates the brakes with the lef foot so that the clutch can already be lightly engaged and the gas pedal (full throttle) in order to bring the vehicle up to the target speed. By simultaneously pressing and holding an operating element, such as the selector lever or a push button on the steering wheel, the race start intention is conveyed to the system, the engine speed adjusted and the start up prevented until the driver releases the brake. During the race start, the clutch is closed under the control of the wheel slip with which the optimal acceleration is achieved and by exploiting the dynamic engine torque (inertia torque). The entire procedure progresses automatically once the driver releases so that even an inexperienced driver can achieve the best possible drive performance figures. Obviously, the driver can cancel the procedure by removing his/her foot from the gas pedal or touching the brakes. Also, the system recognizes when the street conditions do not permit a race start, such as wet roads, for example. Due to the optimal start-up and a shifting sequence into second gear free of traction interruption (see also sports shifting), the race start function enables the acceleration time of 0 to 100 km/h to be improved by an average of 0.2 sec compared to a car with a manual transmission. At the same time, this functionality helps avoid improper use and resulting clutch overload. The top chart in Fig. 7 illustrates the engine and transmission input shaft speed, the lower chart shows the vehicle′s longitudinal acceleration. Starting with a cranking speed of 6,800 rpm, the clutch begins to close, which leads to an engine pressure up to about 4,000 rpm. The dynamic engine torque used to achieve this results in an acceleration of 0.7-0.9 g. In the process, noticeable vibrations in the transmission input shaft speed signal develop due to the wheel slip regulation. After about 1.2 sec, the vehicle is accelerated only by the engine torque with approx. 0.5 g. It must be mentioned here that this test was performed using a vehicle with very high traction. In most cases, a starting speed of only up to about 4,000 rpm is reasonable. A further function developed for the dual clutch transmission is so-called sports shifting. This is described in more detail below. In general, a gear-shift change by the driver is only perceived acoustically by the change in the engine speed. The transition from the acceleration level of the original gear to Fig.7　Measurement of a race star the new gear should be made smoothly and continuously. This also corresponds to the standard shifting sequences in auto-matic and dual clutch transmissions. However, many drivers of sporty cars wish that they had the option of both distinctive comfort shifting sequences as well as sporty shifting sequences, which, besides the haptic response (acceleration jolt), also have an acceleration advantage as a result. To this end, the dynamic engine torque can also be used again. The requirement for this is the torque capacity of the dual clutch which has to be able to transmit this torque increase. As the possible torque increase depends on the gradients of the engine speed, this can be used particularly effectively in shifting gears with a large speed difference with the target gear (large ratio spread/ratio step), which is why the gear changes 1-2, 2-3, and 3-4 are offered. In the process, sports shifting from the frst to second gear can serve as a supplement to the ace start for improving the acceleration time from to 100 km/h. As the use of the dynamic torque is pure application topic, we distinguish, as a rule,between three shifting systems. Fig. 8 illustrates he stylized differences and features between the hifting systems, Fig. 9 shows an original measurement from a prototype vehicle. The top chart shows the respective engine and ransmission speed, the bottom chart shows the orques from both clutches. The bottom line in the hart represents the clutch from the target gear that is used to achieve the torque increase during engine sp eed adjustment and thereby acceleration gains. Fig.8　Simplified depiction of acceleration procedures with Fig.9　Measurement of sports shift 2-3 in the vehicle 附錄B 外文文獻(xiàn)翻譯 運(yùn)動(dòng)型7速雙離合器變速器系統(tǒng) 摘要：ZF公司的7速雙離合器變速器是一款創(chuàng)新型的、適用于運(yùn)動(dòng)型車(chē)輛的變速器。精密的速比和自然擁有的極佳駕駛性能使得它成為運(yùn)動(dòng)型車(chē)輛理想的變速裝置。本文對(duì)該變速器緊湊的齒輪機(jī)構(gòu)、可改善效率和提高發(fā)動(dòng)機(jī)-速度-強(qiáng)度的直接噴射潤(rùn)滑系統(tǒng),雙離合器系統(tǒng)及基于預(yù)先控制原理的液壓控制單元等作了詳細(xì)介紹。在出現(xiàn)電氣故障時(shí)液壓控制系統(tǒng)可選用液壓巡航模式。另外,變速器設(shè)計(jì)、功能特性等也都體現(xiàn)出變速器具有鮮明的運(yùn)動(dòng)特征。 關(guān)鍵詞：自動(dòng)變速器;雙離合器;車(chē)輛連接;效率 1.前言 提及自動(dòng)變速器時(shí),雙離合器系統(tǒng)被普遍認(rèn)為是運(yùn)動(dòng)型的標(biāo)桿?；谥虚g軸結(jié)構(gòu)的該類(lèi)變速器的優(yōu)點(diǎn)是非常直接的“車(chē)輛連接”、高轉(zhuǎn)速性能和及其優(yōu)越的變速器效率。 本文介紹的用于標(biāo)準(zhǔn)型傳動(dòng)系統(tǒng)的7速雙離合器變速器的最大轉(zhuǎn)矩可達(dá)520 Nm、最高轉(zhuǎn)速為9250 rpm。為在現(xiàn)有安裝空間內(nèi)實(shí)現(xiàn)這些性能數(shù)據(jù),創(chuàng)造性的引入了儲(chǔ)油室和潤(rùn)滑油直接噴射概念。在詳細(xì)介紹變速器各特點(diǎn)之前,首先對(duì)變速器給出一個(gè)總的描述,見(jiàn)圖1。 圖1　雙離合器變速器(DCT)剖視圖 發(fā)動(dòng)機(jī)轉(zhuǎn)矩經(jīng)過(guò)扭轉(zhuǎn)減振器(未在圖1中表示)傳遞給雙離合器。雙離合器中的多片式離合器沿徑向互相嵌套并將轉(zhuǎn)矩通過(guò)兩輸入軸傳遞給中間軸齒輪裝置。這里,因?yàn)榘惭b空間的緣故,中間軸并不位于主軸下方,而是橫向斜置。用于采用了帶干油箱的直接噴射潤(rùn)滑,才有這樣的可能。一方面,直接噴射改善了熱傳遞,另一方面不會(huì)在油底殼中出現(xiàn)