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SY-025-BY-2
畢業(yè)設(shè)計(jì)(論文)任務(wù)書
學(xué)生姓名
譚鴻亮
系部
汽車與交通工程院
專業(yè)、班級(jí)
車輛工程07-10
指導(dǎo)教師姓名
趙晨光
職稱
講師
從事
專業(yè)
車輛工程
是否外聘
□是否
題目名稱
乘用車機(jī)械式變速器設(shè)計(jì)
一、設(shè)計(jì)(論文)目的、意義
汽車變速器是汽車傳動(dòng)系的重要組成部分。由于汽油機(jī)額定轉(zhuǎn)矩對(duì)應(yīng)的速度范圍很小,需要用齒輪傳動(dòng)來(lái)適應(yīng)駕駛時(shí)車速的變化。它是傳動(dòng)系的主要部件,它的性能對(duì)整車的動(dòng)力性、燃油經(jīng)濟(jì)性以及乘坐舒適性等方面都有十分重要的影響。設(shè)計(jì)好變速器對(duì)汽車的性能,安全性以及經(jīng)濟(jì)性有著重要作用。
手動(dòng)機(jī)械變速器可以完全遵從駕駛者的意志,且結(jié)構(gòu)簡(jiǎn)單、傳動(dòng)效率高、故障率相對(duì)較低、物美價(jià)廉,因此在市場(chǎng)上仍占有一席之地,開發(fā)手動(dòng)機(jī)械變速器也適應(yīng)當(dāng)代世界經(jīng)濟(jì)的發(fā)展。隨著科技的高速發(fā)展,節(jié)能與環(huán)境保護(hù)、應(yīng)用新型材料、高性能及低成本都可將作為汽車新型變速器的研究方向。
二、設(shè)計(jì)(論文)內(nèi)容、技術(shù)要求(研究方法)
基本內(nèi)容:在保證汽車有必要的動(dòng)力性和經(jīng)濟(jì)性的前提下,進(jìn)行齒輪和傳動(dòng)軸設(shè)計(jì),設(shè)置動(dòng)力輸出裝置,保證換擋迅速、省力、方便,工作可靠。有較高的工作效率,除此之外,還要保證變速器滿足輪廓尺寸和質(zhì)量小、制造成本低、維修方便等要求。在設(shè)計(jì)中要解決的的主要問(wèn)題:在設(shè)計(jì)中需要解決變速器是否能有效預(yù)防脫檔,跳檔并方便掛檔。減小噪音并盡量能達(dá)到輕量化、高承載、低噪聲、換檔操縱好和經(jīng)濟(jì)實(shí)用性。具體內(nèi)容包括:變速器軸、齒輪的設(shè)計(jì);變速器操縱機(jī)構(gòu)的設(shè)計(jì);變速器軸及齒輪的校核。
技術(shù)要求:具有良好的動(dòng)力性與經(jīng)濟(jì)性,換擋迅速、省力、方便。變速器的工作噪聲低,變速器還應(yīng)當(dāng)滿足輪廓尺寸和質(zhì)量小、制造成本低、拆裝容易、維修方便等要求。
三、設(shè)計(jì)(論文)完成后應(yīng)提交的成果
1.變速器的總裝配圖一張(A0);
2.變速器的部件圖、零件圖(軸及齒輪等)折合兩張以上零號(hào)圖(A1、A2若干張);
3.撰寫設(shè)計(jì)說(shuō)明書一份,1.5萬(wàn)字以上。
四、設(shè)計(jì)(論文)進(jìn)度安排
1.調(diào)研,資料收集,完成開題報(bào)告 第1~2周(2月28日-3月13日)
2.分析搜集到的資料,提出最優(yōu)設(shè)計(jì)方案,進(jìn)行相關(guān)計(jì)算
第3~5 周(3月14日-4月3日)
3.繪制機(jī)械變速器總裝配圖及零部件圖的草圖 第6~8周(4月4日-4月24日)
4.繪制機(jī)械變速器總裝配圖、零件圖,撰寫設(shè)計(jì)說(shuō)明書 第9~12周(4月25日-5月22日)
5. 完善設(shè)計(jì),提交指導(dǎo)老師審核并修改 第13~14周(5月23日-6月5日)
6. 提交系里評(píng)閱并修改,準(zhǔn)備答辯 第15~16周(6月6日-6月19日)
7. 畢業(yè)設(shè)計(jì)答辯 第17周(6月20日-6月26日)
五、主要參考資料
[1] 劉惟信.汽車設(shè)計(jì)[M].北京.清華大學(xué)出版社.2001.
[2] 王望予.汽車設(shè)計(jì)[M].北京.機(jī)械工業(yè)出版社.2004.
[3] 常思勤.汽車動(dòng)力裝置[M].北京.機(jī)械工業(yè)出版社.2005.
[4] 林紹義.一種汽車變速器設(shè)計(jì)[J].機(jī)電技術(shù),2004.1.
[5] 劉法順.乘用車兩軸式機(jī)械變速器的設(shè)計(jì)[J].交通科技與經(jīng)濟(jì),2008.4.
[6] 羅春香.汽車變速器設(shè)計(jì)中速比分配問(wèn)題的研究[J].西南民族大學(xué)學(xué)報(bào)·自然科學(xué)版,2004.30.
[7] 韋志林.汽車變速器軸承壽命的校核計(jì)算[J].廣西工學(xué)院學(xué)報(bào),2000.6.
[8] 王之煦,許杏根.簡(jiǎn)明機(jī)械設(shè)計(jì)手冊(cè)[M].北京:機(jī)械工業(yè)出版社,1997.9.
[9] 嚴(yán)倉(cāng)鋒.變速器后蓋總成軸承裝配技術(shù)改造[J].實(shí)用技術(shù),2005.12.
六、備注
指導(dǎo)教師簽字:
年 月 日
教研室主任簽字:
年 月 日
附件:畢業(yè)論文排版示例
本科學(xué)生畢業(yè)設(shè)計(jì)
乘用車機(jī)械式變速器設(shè)計(jì)
項(xiàng)目名華文中宋四號(hào)字,填加文字楷體_GB2312小三號(hào)居下劃線中
院系名稱: 汽車與交通工程學(xué)院
專業(yè)班級(jí): 車輛工程 07-10班
學(xué)生姓名: 譚鴻亮
指導(dǎo)教師: 趙晨光
職 稱: 講師
黑 龍 江 工 程 學(xué) 院
二○一一年六月
論文封面示例,同前
外文封面示例Times New Roman體,字號(hào)與中文對(duì)應(yīng)
The Graduation Thesis for Bachelor's Degree
The Design of the Mechanical Transmission of Passnger
Candidate:Tan Hong liang
Specialty:Vehicle Engineering
Class: BW07-10
Supervisor:Zhao Chen guang
Lecturer
Heilongjiang Institute of Technology
2011-06·Harbin
畢業(yè)設(shè)計(jì)(論文)開題報(bào)告
設(shè)計(jì)(論文)題目: 乘用車機(jī)械式變速器設(shè)計(jì)
院 系 名 稱: 汽車與交通工程學(xué)院
專 業(yè) 班 級(jí): 車輛07-10班
學(xué) 生 姓 名: 譚鴻亮
導(dǎo) 師 姓 名: 趙晨光
開 題 時(shí) 間: 2011年3月16日
指導(dǎo)委員會(huì)審查意見:
簽字: 年 月 日
開題報(bào)告撰寫要求
一、“開題報(bào)告”參考提綱
1. 課題研究目的和意義;
2. 文獻(xiàn)綜述(課題研究現(xiàn)狀及分析);
3. 基本內(nèi)容、擬解決的主要問(wèn)題;
4. 技術(shù)路線或研究方法;
5. 進(jìn)度安排;
6. 主要參考文獻(xiàn)。
二、“開題報(bào)告”撰寫規(guī)范
請(qǐng)參照《黑龍江工程學(xué)院本科生畢業(yè)設(shè)計(jì)說(shuō)明書及畢業(yè)論文撰寫規(guī)范》要求。字?jǐn)?shù)應(yīng)在4000字以上,文字要精練通順,條理分明,文字圖表要工整清楚。
畢業(yè)設(shè)計(jì)(論文)開題報(bào)告
學(xué)生姓名
譚鴻亮
系部
汽車與交通工程學(xué)院
專業(yè)、班級(jí)
車輛工程07-10班
指導(dǎo)教師姓名
趙晨光
職稱
講師
從事專業(yè)
車輛工程
是否外聘
□是 否
題目名稱
乘用車機(jī)械式變速器設(shè)計(jì)
一、課題研究現(xiàn)狀、選題目的和意義
現(xiàn)狀:汽車變速器是影響整車動(dòng)力性,經(jīng)濟(jì)性,舒適性的重要總成。近年來(lái),中國(guó)乘用車變速器市場(chǎng)正處于高速發(fā)展期,2009年我國(guó)汽車變速器市場(chǎng)規(guī)模達(dá)520億元,并且5年來(lái)以每年,超過(guò)20%的速度不斷擴(kuò)大,隨著乘用車銷售量的快速增長(zhǎng),乘用車變速器市場(chǎng)規(guī)模將越來(lái)越大。
世界最大的手動(dòng)變速器制造商德國(guó) ZF公司預(yù)測(cè)說(shuō),到2012年北美市場(chǎng)出售的汽車中將只有6%是手動(dòng)擋。歐洲與美國(guó)的情況有很大不同。有機(jī)構(gòu)預(yù)測(cè),到2013年,歐洲有52%的汽車還是手動(dòng)擋,配備自動(dòng)手動(dòng)變速器的將占10%,配備無(wú)極變速器的將占2%,配備雙離合器變速器的將占16%。歐洲人崇尚節(jié)能、環(huán)保,喜歡開小型車,更親睞手動(dòng)變速器的經(jīng)濟(jì)燃油性。
在我國(guó),據(jù)調(diào)查2007年手動(dòng)變速器的市場(chǎng)比重為74%,占據(jù)較大的市場(chǎng)份額。從2002到2007年間自動(dòng)檔變速器市場(chǎng)占有率從9%增長(zhǎng)到26%,Global Insight公司預(yù)計(jì)到2012年自動(dòng)檔變速器將占據(jù)33%的份額,而乘用車市場(chǎng)自動(dòng)檔所占的比例可能達(dá)到44%。從2002-2006年間,女性用戶從20.3%增長(zhǎng)到30.9%,而自動(dòng)檔變速器使用方便特點(diǎn)深受女性用戶群的喜愛。另外在消費(fèi)者調(diào)查中最受關(guān)注的汽車配件中,第一名是安全氣囊,第二就是自動(dòng)檔的變速器,在中國(guó)自動(dòng)檔變速器的市場(chǎng)是十分樂(lè)觀的。同時(shí)手動(dòng)檔變速器的節(jié)能型,經(jīng)濟(jì)性以及駕駛娛樂(lè)性也決定了其不可替代性。
總體來(lái)看,今年我國(guó)自主乘用車變速器企業(yè)發(fā)展勢(shì)頭良好,受惠于國(guó)家節(jié)能減排政策影響,小排量乘用車銷量的提升帶動(dòng)變速器配套數(shù)量增長(zhǎng),今年小排量車用變速器表現(xiàn)突出。
我國(guó)明年乘用車市場(chǎng)上,由于自主品牌變速器在小排量緊湊型乘用車市場(chǎng)地位穩(wěn)固,國(guó)產(chǎn)變速器預(yù)期可能會(huì)有12%~15%的增長(zhǎng)。隨著一線城市汽車數(shù)量逐漸飽和,乘用車市場(chǎng)自然會(huì)向二、三線城市轉(zhuǎn)移。二、三線城市消費(fèi)者由于購(gòu)買力相對(duì)有限,第一次購(gòu)車大多選擇性價(jià)比較高的自主品牌車和小排量車,這無(wú)論對(duì)自主品牌乘用車還是自主品牌乘用車變速器企業(yè)都是機(jī)遇。
目的和意義:汽車變速器是汽車傳動(dòng)系的重要組成部分。而手動(dòng)機(jī)械式變速器可以完全遵從駕駛者的意志可以給其帶來(lái)更多的操控快感,手動(dòng)變速的汽車在加速、超車時(shí)比自動(dòng)變速車快,維修保養(yǎng)上也便宜,且結(jié)構(gòu)簡(jiǎn)單,傳輸效率高(比較省油),故障率相對(duì)較低,物美價(jià)廉,所以在中國(guó)乘用車市場(chǎng)一直占據(jù)著汽車變速器的主導(dǎo)地位。開發(fā)手動(dòng)機(jī)械變速器也適應(yīng)當(dāng)代世界經(jīng)濟(jì)的發(fā)展。隨著科技的高速發(fā)展,節(jié)能與環(huán)境保護(hù)、應(yīng)用新型材料、高性能及低成本都可將作為汽車新型變速器的研究方向。
二、設(shè)計(jì)(論文)的基本內(nèi)容、擬解決的主要問(wèn)題
基本內(nèi)容:
(1)變速器傳動(dòng)機(jī)構(gòu)的設(shè)計(jì)(包括各檔齒輪、輸入與輸出軸、同步器等);
(2)變速器操縱機(jī)構(gòu)的設(shè)計(jì);
(3)變速器箱體以及其它部件的設(shè)計(jì);
(4)變速器各主要部件的校核。
擬解決的問(wèn)題:
(1)使變速器能有效的防止脫檔,跳檔,并方便掛檔。
(2)減小噪音并盡量能達(dá)到輕量化、高承載、低噪聲、換檔操縱性好和經(jīng)濟(jì)實(shí)用性
(3)使變速器具有良好的動(dòng)力性與經(jīng)濟(jì)性,換擋迅速、省力、方便。
擬解決方案:
(1)為減輕駕駛員的疲勞強(qiáng)度,提高行駛安全性,操縱輕便的要求日益顯得重要,這可通過(guò)采用同步器和預(yù)選氣動(dòng)換檔或自動(dòng)、半自動(dòng)換檔來(lái)實(shí)現(xiàn)。
(2)采用斜齒輪傳動(dòng)及選擇合理的變位系數(shù),提高制造精度和安裝剛性可減小齒輪的噪聲。
(3)應(yīng)保證汽車具有高的動(dòng)力性和經(jīng)濟(jì)性指標(biāo)。合理的選擇變速器檔數(shù)及傳動(dòng)比,來(lái)滿足這一要求。
三、技術(shù)路線(研究方法)
四、進(jìn)度安排
1.調(diào)研,資料收集,完成開題報(bào)告 第1~2周(2月28日-3月13日)
2.分析搜集到的資料,提出最優(yōu)設(shè)計(jì)方案,進(jìn)行相關(guān)計(jì)算
第3~5 周(3月14日-4月3日)
3.繪制機(jī)械變速器總裝配圖及零部件圖的草圖 第6~8周(4月4日-4月24日)
4.繪制機(jī)械變速器總裝配圖、零件圖,撰寫設(shè)計(jì)說(shuō)明書 第9~12周(4月25日-5月22日)
5. 完善設(shè)計(jì),提交指導(dǎo)老師審核并修改 第13~14周(5月23日-6月5日)
6. 提交系里評(píng)閱并修改,準(zhǔn)備答辯 第15~16周(6月6日-6月19日)
7. 畢業(yè)設(shè)計(jì)答辯 第17周(6月20日-6月26日)
五、參考文獻(xiàn)
[1] 劉惟信.汽車設(shè)計(jì)[M].北京.清華大學(xué)出版社.2001.
[2] 王望予.汽車設(shè)計(jì)[M].北京.機(jī)械工業(yè)出版社.2004.
[3] 常思勤.汽車動(dòng)力裝置[M].北京.機(jī)械工業(yè)出版社.2005.
[4] 林紹義.一種汽車變速器設(shè)計(jì)[J].機(jī)電技術(shù),2004.1.
[5] 劉法順.乘用車兩軸式機(jī)械變速器的設(shè)計(jì)[J].交通科技與經(jīng)濟(jì),2008.4.
[6] 羅春香.汽車變速器設(shè)計(jì)中速比分配問(wèn)題的研究[J].西南民族大學(xué)學(xué)報(bào)·自然科學(xué)版,2004.30.
[7] 韋志林.汽車變速器軸承壽命的校核計(jì)算[J].廣西工學(xué)院學(xué)報(bào),2000.6.
[8] 王之煦,許杏根.簡(jiǎn)明機(jī)械設(shè)計(jì)手冊(cè)[M].北京:機(jī)械工業(yè)出版社,1997.9.
[9] 嚴(yán)倉(cāng)鋒.變速器后蓋總成軸承裝配技術(shù)改造[J].實(shí)用技術(shù),2005.12.
[10] 陳家瑞.汽車構(gòu)造[M].北京. 機(jī)械工業(yè)出版社.2005.
[11] 王少懷.機(jī)械設(shè)計(jì)師手冊(cè)[M].北京.電子工業(yè)出版社.2006.
[12] 殷玉楓.機(jī)械設(shè)計(jì)課程設(shè)計(jì)[M].北京. 機(jī)械工業(yè)出版社.2006.
[13] 于志生.汽車?yán)碚揫M].北京. 機(jī)械工業(yè)出版社.2000.
[14] 向立明.汽車變速器的發(fā)展歷史和未來(lái)趨勢(shì)[M].公路與運(yùn)輸.2007.
[15] 楊可楨 程光蘊(yùn) 李仲生.機(jī)械設(shè)計(jì)基礎(chǔ)[M].北京.高等教育出版社.2006.
[16] 成大先.機(jī)械設(shè)計(jì)手冊(cè)[M].北京.化學(xué)工業(yè)出版社.2004.
[17] 王寶璽 賈慶祥.汽車制造工藝學(xué)[M].北京. 機(jī)械工業(yè)出版社.2007.
[18] 王大全.汽車常用數(shù)據(jù)手冊(cè)[M].北京.化學(xué)工業(yè)出版社.2006.
[19] Amir Ibrahim,A,Qin Dation,LiuZhengjun,Acontrol strategy on starting up of vehicle with automatic manual transmission (AMT) [J],Information technology,2005,4 (2) :140-145
[20] SebulkeA.The Two-Mass Flywheel-a torsional Vibration Damper For the Power Train of Passenger Cars state of the Art and Further technical Development.(SAE870394).SAE Transaction.1987(2):89-98
六、備注
指導(dǎo)教師意見:
簽字: 年 月 日
黑龍江工程學(xué)院本科生畢業(yè)設(shè)計(jì)
摘 要
變速器用來(lái)改變發(fā)動(dòng)機(jī)傳到驅(qū)動(dòng)輪上的轉(zhuǎn)矩和轉(zhuǎn)速,目的是在原地起步、爬坡、轉(zhuǎn)彎、加速等各種行駛工況下,使汽車獲得不同的牽引力和速度,同時(shí)使發(fā)動(dòng)機(jī)在最有利的工況范圍內(nèi)工作。機(jī)械式手動(dòng)變速器是傳統(tǒng)的汽車傳動(dòng)系統(tǒng),由于其結(jié)構(gòu)簡(jiǎn)單、體積小、制造成本低、便于裝配和修理,傳動(dòng)效率高等優(yōu)點(diǎn),一直沿用至今。變速器的性能直接體現(xiàn)出整車性能的高低,特別是燃油經(jīng)濟(jì)性的好壞。所以變速器的設(shè)計(jì)質(zhì)量的高低一直是汽車行業(yè)競(jìng)爭(zhēng)的焦點(diǎn)。
隨著汽車工業(yè)的發(fā)展,轎車變速器的設(shè)計(jì)趨勢(shì)為增大變速器傳遞功率與重量之比,并要求變速器具有較小的尺寸和良好性能。在給定發(fā)動(dòng)機(jī)輸出轉(zhuǎn)矩、轉(zhuǎn)速及最高車速、最大爬坡度等條件下,著重對(duì)變速器齒輪的結(jié)構(gòu)參數(shù)、軸的結(jié)構(gòu)尺寸等進(jìn)行設(shè)計(jì)計(jì)算。
關(guān)鍵詞:變速器;齒輪;同步器;設(shè)計(jì)
ABSTRACT
The transmission is been used to transform an engine to spread to drive the torque and the revolving speed on the wheel, the purpose is an earth to start and climb various condition that drove works, such as ascent, turn and acceleration...etc. at first down,make different travtive force of autocar acquisition and velocity, make the engine work in the most beneficial work condition range at the same time. Mechanical transmission is a traditional manual transmission car, because of its simple structure, small size, low manufacturing cost, ease of assembly and repair, high transmission efficiency, are still in use. Transmission performance of the vehicle directly reflects the level of performance, especially fuel economy is good or bad. Therefore, the design of transmission quality has been the focus of competition in the automotive industry.
Along with the development of the automobile industry ,the trend of car transmission designing is to increase it stransmission power and decrese its weight ,and hope have smaller size and excellent performance. In conditions that knowing the engine output torque , speed of engine and maximum speed of vehicles , maximum degree , focus on the designing of transmission gear structural parameters , axis geometry design computation ; as well as the transmission and drive program structure design
Key words :Transmission ;Gear ; Synchrotron ;Design
I
SY-025-BY-1
畢業(yè)設(shè)計(jì)(論文)題目審定表
指導(dǎo)教師姓名
趙晨光
職稱
講師
從事
專業(yè)
車輛工程
是否外聘
□是■否
題目名稱
乘用車機(jī)械式變速器設(shè)計(jì)
課題適用專業(yè)
車輛工程
課題類型
其它
課題簡(jiǎn)介:(主要內(nèi)容、意義、現(xiàn)有條件、預(yù)期成果及表現(xiàn)形式。)
指導(dǎo)教師簽字: 年 月 日
教
研
室
意
見
1
選題與專業(yè)培養(yǎng)目標(biāo)的符合度
□好
□較好
□一般
□較差
2
對(duì)學(xué)生能力培養(yǎng)及全面訓(xùn)練的程度
□好
□較好
□一般
□較差
3
選題與生產(chǎn)、科研、實(shí)驗(yàn)室建設(shè)等實(shí)際的結(jié)合程度
□好
□較好
□一般
□較差
4
論文選題的理論意義或?qū)嶋H價(jià)值
□好
□較好
□一般
□較差
5
課題預(yù)計(jì)工作量
□較大
□適中
□較小
6
課題預(yù)計(jì)難易程度
□較難
□一般
□較易
教研室主任簽字: 年 月 日
系(部)教學(xué)指導(dǎo)委員會(huì)意見:
負(fù)責(zé)人簽字: 年 月 日
注:課題類型填寫 W.科研項(xiàng)目;X.生產(chǎn)(社會(huì))實(shí)際;Y.實(shí)驗(yàn)室建設(shè);Z.其它。
附錄:
THE FILE TRANSMISSION GEAR SELECTION
OF THE BASIC PARAMETERS
1, Reasonable choice of module:
Modulus is an important gear basic parameters, the greater the modulus, the greater the tooth thickness, the bending strength of gear is also greater, and its greater carrying capacity. Instead modulus smaller tooth thickness will be thinner, the bending strength of gear will be smaller. The low profile of the gear, due to the low rotational speed, torque, and gear of the relatively large bending stress, so need to choose a larger module in order to ensure its strength. And high-speed file gear, due to the high-speed, torque small gear bending stress is relatively small, so to ensure that the bending strength of gear under the premise of the general selection of the smaller module, so that gear teeth can be increased in order to obtain larger degree of overlap, so as to achieve the purpose of reducing noise.
In a modern gearbox design, the file selection module gear is different. For example, a transmission gear of a file to the five-gear gear module are: 3.5; 3; 2.75; 2.5; 2; to change over the past modulus or modulus of the same can not be the situation of Latin America.
2, a reasonable selection of pressure angle:
When a gear module and set the number of teeth, the gear diameter is determined, and the gear tooth involute base circle depends on the size, the size of the base circle and under pressure angle. For the same pitch circle of gear, if its pitch circle a different pressure angle, base circle is different. When the greater the pressure angle, the base circle diameter of the smaller, more curved involute, tooth root of the tooth will thicken, increase the tooth surface radius of curvature, which can increase the tooth bending strength and contact strength. When reducing the pressure angle, the base will become larger diameter, involute tooth profile will change some of the straight, thinning of the tooth root, tooth smaller radius of curvature, making the tooth bending strength and contact intensity will decrease, but decrease with the pressure angle, to increase the contact ratio gears, reducing the stiffness of the tooth, and can reduce the entry and exit load at the time of engagement, all of which are beneficial to reduce noise. There-fore, low profile gear, often larger pressure angle in order to meet the strength requirements; and regular use of high-speed file smaller gear pressure angle in order to meet the requirements of its lower noise.
For example: a gear module 3, the number of teeth of 30, when the pressure angle of 17.5 degrees for the circular tooth thickness of the base to 5.341; when the pressure angle of 25 degrees, the tooth thickness of the base circle to 6.716; its base circle to increase the tooth thickness 25%, so increase the pressure angle to increase their flexural strength.
3, A reasonable selection of Helix Angle:
Compared with the straight gear, helical gear drive with a smooth, coincidence degree, the impact is small and the advantages of small noise. As a result of the present with synchronous transmission, and transmission will no longer be a direct mobile gear meshing with another gear, but with all the gears are meshing, so that'll bring convenience to the use of helical gear, so to bring the gearbox synchronizer Most of the use of helical gear.
Helical gear as a result of the characteristics of the entire tooth width decision not to enter the mesh at the same time all but one end of first gear into the mesh, with the drive gear along the tooth width direction mesh gradually until all the teeth have wide access to mesh, so the actual meshing helical gear spur the region than the large. When the tooth when a certain width, the contact ratio of helical gear with helix angle increases. Carrying capacity is also stronger, have better stability. In theory, the better helix angle, but the helix angle increases, the axial force will also increase, so that reduces the transmission efficiency.
In the modern design of the gearbox, in order to ensure smooth gear drive, low noise and less impact, all . Files for°gear should choose a larger helix angle, generally about 30 high-speed gear as a result of the higher speed, for a smooth, low impact, low noise, so the use of small modulus, large helical angle; and low-profile gear module using the larger, smaller helix angle.
4, The perspective of a reasonable modification is selected:
With good conditions for the lubrication of the hardened gear is generally believed that the main danger is in the cycle under alternating stress, the fatigue crack Dedendum gradual expansion of the tooth root fracture caused by the failure. Failure in the gear transmission is a part of this. In order to avoid a broken tooth, should be to maximize the tooth root bending strength, and the use is changed, and can achieve this objective. Under normal circumstances, the greater the coefficient, the smaller values tooth, tooth bending stress on the smaller, the higher the bending strength of teeth.
In the hardened gear, the tooth surface pitting failure is one of the reasons off. Increased engagement angle, can reduce the inter-tooth contact stress and maximum slip rates, can greatly increase the ability of anti-pitting. And increased engagement angle, it must have a gear shift is introduced, thereby enhancing contact strength of tooth surface can improve the flexural strength of tooth roots, so as to enhance the effect of the carrying capacity of gears. However, for helical gear drive, variable coefficient is too large, and will total tooth length of the contact line, but to reduce its carrying capacity. At the same time, the greater the coefficient, as a result of tooth to tip increases, the thickness of the tip will be smaller, which will affect the strength of the top teeth.
Therefore, in the design of a modern gearbox, the majority of all reasonable use of gear shift is the angle in order to maximize its advantages. Mainly in the following design criteria:
low profile for the gear pair, the driving gear of the coefficient should be larger than the passive gear shift coefficient, and pair of high-speed profile, the driving gear of the coefficient should be less than passive coefficient gear.
gear with the modification coefficient increased gradually stalls xiajiang. This is because low-grade zones as a result of low rotational speed, torque, and gear for high intensity, so the need to use more of the modification coefficient da.
The total of the gear profile shift coefficient is positive (of the anglel shift as amended), and increased with the stalls and gradually decreased. The smaller the total coefficient, a pair of pair of tooth root of the thickness of the total will be thin, tooth root becomes weak, the lower the bending strength, but decreased as a result of the stiffness of the tooth, easy to absorb shock and vibration, so can reduce the noise. And tooth contact ratio will increase, which bear a single tooth at the time of maximum load Dedendum recent focus distance, the reduced bending moment, which is equivalent to increase the strength of the tooth root, which as a result of thinning and weakened tooth root strength offset factor. Therefore, the greater the overall coefficient, the higher the strength of the tooth root, but the noise may increase. Thus high-speed gear to choose a smaller file of the total coefficient, and low-profile gear must be chosen larger coefficient
5, to improve tip high coefficient:
Top gear in the transmission of high quality factor, the impact of focusing on adaptation, in the main impact of helical gear contact ratio face. Coincidence degree by the end of the formula, we can see that when the number of teeth and meshing certain angle, the tooth tip is affected by tooth pressure angle coefficient of the top high impact factor the greater the high-tip, round tip the greater the pressure angle, contact ratio is The greater and ore stable drive. However, the high coefficient the greater the tip, the thickness of the top teth will become thin, thus affecting the strength tip. At the same time, at least not from the tooth root formula, the high coefficient the greater the tip, at least not the root will increase the number of gear, otherwise, they would have a root cutting. As a result, guarantees of non-root tip-cut and sufficient strength, increased tooth top high coefficient of coincidence degree for the increase is significant.
Top gear in the transmission of high quality factor, the impact of focusing on adaptation, in the main impact of helical gear contact ratio face. Coincidence degree by the end of the formula, we can see that when the number of teeth and meshing certain angle, the tooth tip is affected by tooth pressure angle coefficient of the top high impact factor the greater the high-tip, round tip the greater the pressure angle, contact ratio is The greater and more stable drive. However, the high coefficient the greater the tip, the thickness of the top teeth will become thin, thus affecting the strength tip. At the same time, at least not from the tooth root formula, the high coefficient the greater the tip, at least not the root will increase the number of gear, otherwise, they would have a root cutting. As a result, guarantees of non-root tip-cut and sufficient strength, increased tooth top high coeff-icient of coincidence degree for the increase is significant.
The above is from the module, pressure angle, helix angle, coefficient and a high coefficient of this addendum to an independent analysis of the five aspects of gear design trends. In fact between the various para-meters are inter-related, involved with each other, the choice of transmission parameters, it is necessary to take into account their strengths and weaknesses, but also consider the relationship between them, so in order to maximize their strengths and avoid weaknesses to improve transmission performance.
變速箱各檔齒輪基本參數(shù)的選擇
1、合理選用模數(shù)
模數(shù)是齒輪的一個(gè)重要基本參數(shù),模數(shù)越大,齒厚也就越大,齒輪的彎曲強(qiáng)度也越大,它的承載能力也就越大。反之模數(shù)越小,齒厚就會(huì)變薄,齒輪的彎曲強(qiáng)度也就越小。對(duì)于低速檔的齒輪,由于轉(zhuǎn)速低、扭矩大,齒輪的彎曲應(yīng)力比較大,所以需選用較大的模數(shù),以保證其強(qiáng)度要求。而高速檔齒輪,由于轉(zhuǎn)速高、扭矩小,齒輪的彎曲應(yīng)力比較小,所以在保證齒輪彎曲強(qiáng)度的前提下,一般選用較小的模數(shù),這樣就可以增加齒輪的齒數(shù),以得到較大的重合度,從而達(dá)到降低噪聲的目的。
在現(xiàn)代變速箱設(shè)計(jì)中,各檔齒輪模數(shù)的選擇是不同的。例如,某變速箱一檔齒輪到五檔齒輪的模數(shù)分別是:3.5;3;2.75;2.5;2;從而改變了過(guò)去模數(shù)相同或模數(shù)拉不開的狀況。
2、合理選用壓力角
當(dāng)一個(gè)齒輪的模數(shù)和齒數(shù)確定了,齒輪的分度圓直徑也就確定了,而齒輪的漸開線齒形取決于基圓的大小,基圓大小又受到壓力角的影響。對(duì)于同一分度圓的齒輪而言,若其分度圓壓力角不同,基圓也就不同。當(dāng)壓力角越大時(shí),基圓直徑就越小,漸開線就越彎曲,輪齒的齒根就會(huì)變厚,齒面曲率半徑增大,從而可以提高輪齒的彎曲強(qiáng)度和接觸強(qiáng)度。當(dāng)減小壓力角時(shí),基圓直徑就會(huì)變大,齒形漸開線就會(huì)變的平直一些,齒根變薄,齒面的曲率半徑變小,從而使得輪齒的彎曲強(qiáng)度和接觸強(qiáng)度均會(huì)下降,但是隨著壓力角的減小,可增加齒輪的重合度,減小輪齒的剛度,并且可以減小進(jìn)入和退出嚙合時(shí)的動(dòng)載荷,所有這些都有利于降低噪聲。因此,對(duì)于低速檔齒輪,常采用較大的壓力角,以滿足其強(qiáng)度要求;而高速檔齒輪常采用較小的壓力角,以滿足其降低噪聲的要求。
例如:某一齒輪模數(shù)為3,齒數(shù)為30,當(dāng)壓力角為17.5度時(shí)基圓齒厚為5.341;當(dāng)壓力角為25度時(shí),基圓齒厚為6.716;其基圓齒厚增加了25%左右,所以增大壓力角可以增加其彎曲強(qiáng)度。
3、合理選用螺旋角
與直齒輪相比,斜齒輪具有傳動(dòng)平穩(wěn),重合度大,沖擊小和噪聲小等優(yōu)點(diǎn)?,F(xiàn)在的變速箱由于帶同步器,換檔時(shí)不再直接移動(dòng)一個(gè)齒輪與另一個(gè)齒輪嚙合,而是所有的齒輪都相嚙合,這樣就給使用斜齒輪帶來(lái)方便,因此帶同步器的變速箱大多都使用斜齒輪。
由于斜齒輪的特點(diǎn),決定了整個(gè)齒寬不是同時(shí)全部進(jìn)入嚙合的,而是先由輪齒的一端進(jìn)入嚙合,隨著輪齒的傳動(dòng),沿齒寬方向逐漸進(jìn)入嚙合,直到全部齒寬都進(jìn)入嚙合,所以斜齒輪的實(shí)際嚙合區(qū)域比直齒輪的大。當(dāng)齒寬一定時(shí),斜齒輪的重合度隨螺旋角增加而增加。承載能力也就越強(qiáng),平穩(wěn)性也就越好。從理論上講,螺旋角越大越好,但螺旋角增大,會(huì)使軸向分力也增大,從而使得傳遞效率降低了。
在現(xiàn)代變速箱的設(shè)計(jì)中,為了保證齒輪傳動(dòng)的平穩(wěn)性、低噪聲和少?zèng)_擊,所有齒輪都要選擇較大的螺旋角,一般都在30°左右。對(duì)于高速檔齒輪由于轉(zhuǎn)速較高,要求平穩(wěn),少?zèng)_擊,低噪聲,因此采用小模數(shù),大螺旋角;而低速檔齒輪則用較大模數(shù),較小螺旋角。
4、合理選用正角度變位
對(duì)于具有良好潤(rùn)滑條件的硬齒面齒輪傳動(dòng),一般認(rèn)為其主要危險(xiǎn)是在循環(huán)交變應(yīng)力作用下,齒根的疲勞裂紋逐漸擴(kuò)張?jiān)斐升X根斷裂而失效。變速箱中齒輪失效正是屬于這一種。為了避免輪齒折斷,應(yīng)盡量提高齒根彎曲強(qiáng)度,而運(yùn)用正變位,則可達(dá)到這個(gè)目的。一般情況下,變位系數(shù)越大,齒形系數(shù)值就越小,輪齒上彎曲應(yīng)力越小,輪齒彎曲強(qiáng)度就越高。
在硬齒面的齒輪傳動(dòng)中,齒面點(diǎn)蝕剝落也是失效原因之一。增大嚙合角,可降低齒面間的接觸應(yīng)力和最大滑動(dòng)率,能大大提高抗點(diǎn)蝕能力。而增大嚙合角,則必須對(duì)一副齒輪都實(shí)行正變位,這樣既可提高齒面的接觸強(qiáng)度,又可提高齒根的彎曲強(qiáng)度,從而達(dá)到提高齒輪的承載能力效果。但是,對(duì)于斜齒輪傳動(dòng),變位系數(shù)過(guò)大,又會(huì)使輪齒總的接觸線長(zhǎng)度縮短,反而降低其承載能力。同時(shí),變位系數(shù)越大,由于齒頂圓要隨之增大,其齒頂厚度將會(huì)變小,這會(huì)影響齒頂?shù)膹?qiáng)度。
因此在現(xiàn)代變速箱的設(shè)計(jì)中,大多數(shù)齒輪均合理采用正角度變位,以最大限度發(fā)揮其優(yōu)點(diǎn)。主要有以下幾個(gè)設(shè)計(jì)準(zhǔn)則:
l 對(duì)于低速檔齒輪副來(lái)說(shuō),主動(dòng)齒輪的變位系數(shù)應(yīng)大于被動(dòng)齒輪的變位系數(shù),而對(duì)高速檔齒輪副,其主動(dòng)齒輪的變位系數(shù)應(yīng)小于被動(dòng)齒輪的變位系數(shù)。
l 主動(dòng)齒輪的變位系數(shù)隨檔位的升高而逐漸下降。這是因?yàn)榈蜋n區(qū)由于轉(zhuǎn)速低、扭矩大,齒輪強(qiáng)度要求高,因此需采用較da的變位系數(shù)。
l 各檔齒輪的總變位系數(shù)都是正的(屬于角變位修正),而且隨著檔位的升高而逐漸減小??傋兾幌禂?shù)越小,一對(duì)齒輪副的齒根總的厚度就越薄,齒根就越弱,其抗彎強(qiáng)度就越 低,但是由于輪齒的剛度減小,易于吸收沖擊振動(dòng),故可降低噪聲。而且齒形重合度會(huì)增加,這使得單齒承受最大載荷時(shí)的著力點(diǎn)距齒根近,使得彎曲力矩減小,相當(dāng)于提高了齒根強(qiáng)度,這對(duì)由于齒根減薄而消弱強(qiáng)度的因素有所抵消。所以總變位系數(shù)越大,則齒根強(qiáng)度越高,但噪聲則有可能增大。因此高速檔齒輪要選擇較小的總變位系數(shù),而低速檔齒輪則必須選用較大的總變位系數(shù)。
5、提高齒頂高系數(shù)
齒頂高系數(shù)在傳動(dòng)質(zhì)量指標(biāo)中,影響著重合度,在斜齒輪中主要影響端面重合度。由端面重合度的公式可知,當(dāng)齒數(shù)和嚙合角一定時(shí),齒頂圓壓力角是受齒頂高系數(shù)影響的,齒頂高系數(shù)越大,齒頂圓壓力角也越大,重合度也就越大,傳動(dòng)也就越平穩(wěn)。但是,齒頂高系數(shù)越大,齒頂厚度就會(huì)越薄,從而影響齒頂強(qiáng)度。同時(shí),從最少不根切齒數(shù)公式來(lái)看,齒頂高系數(shù)越大,最少不根切齒數(shù)就會(huì)增加,否則的話,就會(huì)產(chǎn)生根切。因此,在保證不根切和齒頂強(qiáng)度足夠的情況下,增大齒頂高系數(shù),對(duì)于增加重合度是有意義的。
因此在現(xiàn)代變速箱的設(shè)計(jì)中,各檔齒輪的齒頂高系數(shù)都選擇較大的值,一般都大于1.0,稱為細(xì)高齒,這對(duì)降低噪聲,增加傳動(dòng)平穩(wěn)性都有明顯的效果。對(duì)于低速檔齒輪,為了保證其具有足夠的齒根彎曲強(qiáng)度,一般選用較小的齒頂高系數(shù);而高速檔齒輪,為了保證其傳動(dòng)的平穩(wěn)性和低噪聲,一般選用較大的齒頂高系數(shù)。
以上是從模數(shù)、壓力角、螺旋角、變位系數(shù)和齒頂高系數(shù)這五個(gè)方面去獨(dú)立分析齒輪設(shè)計(jì)趨勢(shì)。實(shí)際上各個(gè)參數(shù)之間是互相影響、互相牽連的,在選擇變速箱的參數(shù)時(shí),既要考慮它們的優(yōu)缺點(diǎn),又要考慮它們之間的相互關(guān)系,從而以最大限度發(fā)揮其長(zhǎng)處,避免短處,改善變速箱的使用性能。