滌綸短纖后處理設(shè)備七輥牽伸機(jī)的牽伸輥設(shè)計(jì)【cad高清圖紙和說(shuō)明書(shū)打包】[更新1]

【溫馨提示】 dwg后綴的文件為CAD圖，可編輯，無(wú)水印，高清圖，壓縮包內(nèi)文檔可直接點(diǎn)開(kāi)預(yù)覽，需要原稿請(qǐng)自助充值下載，請(qǐng)見(jiàn)壓縮包內(nèi)的文件及預(yù)覽，所見(jiàn)才能所得，請(qǐng)細(xì)心查看有疑問(wèn)可以咨詢QQ：414951605或1304139763 邵陽(yáng)學(xué)院畢業(yè)設(shè)計(jì)（論文）任務(wù)書(shū)專業(yè)班級(jí)2002機(jī)本學(xué)生姓名文藝苑學(xué) 號(hào)057課題名稱滌綸短纖后處理設(shè)備七輥牽伸機(jī)的牽伸輥設(shè)計(jì)設(shè)計(jì)(論文)起止時(shí)間2006 年 2 月 20 日至2006 年 6 月 10 日課題類(lèi)型工程設(shè)計(jì)、應(yīng)用研究、開(kāi)發(fā)研究、軟件工程、理論研究、其他課題性質(zhì)真實(shí)一、 課題研究的目的與主要內(nèi)容課題研究的目的是：1.培養(yǎng)學(xué)生綜合運(yùn)用所學(xué)理論知識(shí)、解決工程問(wèn)題的能力。 2.培養(yǎng)學(xué)生的工程素養(yǎng)，使學(xué)生在文獻(xiàn)檢索，工程資料查閱及運(yùn)用計(jì)算機(jī)繪圖方面得到進(jìn)一步鍛煉。 課題研究的主要內(nèi)容： 1.完成30005000個(gè)單詞以上與滌綸后處理設(shè)備有關(guān)外文資料翻譯（打印稿），譯文要求準(zhǔn)確、文字流暢。2.了解滌綸后處理設(shè)備加工工藝。3.根據(jù)滌綸短纖的年產(chǎn)量，計(jì)算牽伸力的大小，確定牽伸軸及牽伸輥的尺寸。4.完成牽伸輥的結(jié)構(gòu)設(shè)計(jì)，畫(huà)出整套裝配圖及零件圖。5.按統(tǒng)一格式和規(guī)范撰寫(xiě)設(shè)計(jì)說(shuō)明書(shū)。二、 基本要求1. 學(xué)生應(yīng)在教師的指導(dǎo)下按時(shí)完成所規(guī)定的內(nèi)容和工作量，編寫(xiě)符合要求的設(shè)計(jì)計(jì)算說(shuō)明書(shū)，并正確繪制整套機(jī)械圖表。2. 學(xué)生依據(jù)課題任務(wù)，認(rèn)真收集有關(guān)資料，熟悉有關(guān)化學(xué)纖維加工工藝，正確使用各類(lèi)工具書(shū)；掌握有關(guān)工程設(shè)計(jì)的程序、方法和技術(shù)規(guī)范；鍛煉分析與解決工程實(shí)際問(wèn)題的能力。3. 在設(shè)計(jì)中應(yīng)樹(shù)立正確的設(shè)計(jì)思想，培養(yǎng)嚴(yán)肅認(rèn)真的科學(xué)態(tài)度，嚴(yán)謹(jǐn)求實(shí)的工作作風(fēng)。4. 畢業(yè)設(shè)計(jì)說(shuō)明書(shū)應(yīng)包括與設(shè)計(jì)題目有關(guān)的闡述說(shuō)明及計(jì)算，內(nèi)容完整，文字流暢，符合畢業(yè)設(shè)計(jì)規(guī)范。5. 熟練運(yùn)用CAD繪制機(jī)械圖表。注：1、此表由指導(dǎo)教師填寫(xiě)，經(jīng)各系、教研室主任審批生效； 2、此表1式3份，學(xué)生、指導(dǎo)教師、教研室各1份。三、課題研究已具備的條件（包括實(shí)驗(yàn)室、主要儀器設(shè)備、參考資料）該產(chǎn)品在邵陽(yáng)紡織機(jī)械股份公司已開(kāi)始研制，并取得一定的效果，邵陽(yáng)紡織機(jī)械股份公司可提供一定的技術(shù)支持。 1.滌綸短纖生產(chǎn) 東南大學(xué)出版社 1999年 2.機(jī)械設(shè)計(jì)手冊(cè)（上、中、下） 化學(xué)出版社 2000年 3.化纖機(jī)械設(shè)計(jì) 中國(guó)紡織出版社 1997年四、設(shè)計(jì)（論文）進(jìn)度表2月20日3月10日，熟悉課題，進(jìn)行調(diào)研，收集有關(guān)資料，擬訂設(shè)計(jì)方案3月11日4月21日，進(jìn)行有關(guān)分析計(jì)算，確定設(shè)備基本結(jié)構(gòu)，完成技術(shù)設(shè)計(jì)4月22日5月21日，進(jìn)行施工設(shè)計(jì)，完成所有圖表，撰寫(xiě)設(shè)計(jì)計(jì)算說(shuō)明書(shū)5月22日6月10日，設(shè)計(jì)修改、完善，完成答辯五、教研室審批意見(jiàn)教研室主任（簽名） 年 月 日六、院（系）審批意見(jiàn)院（系）負(fù)責(zé)人（簽名） 單位（公章） 年 月 日指導(dǎo)教師（簽名） 學(xué)生（簽名）13邵陽(yáng)學(xué)院畢業(yè)設(shè)計(jì)（論文）內(nèi)容提要滌綸短纖維后處理設(shè)備七輥牽伸機(jī)牽伸輥屬于牽伸機(jī)的工作部分，合理設(shè)計(jì)將提高七輥牽伸機(jī)的性能。牽伸機(jī)是紡絲后處理的主要設(shè)備之一，根據(jù)紡絲的工藝要求來(lái)確定牽伸機(jī)的數(shù)量和功率。本次設(shè)計(jì)的七輥牽伸機(jī)主要是為了提高年產(chǎn)量，從牽伸機(jī)組的整體設(shè)計(jì)出發(fā)，按照總牽伸倍數(shù)合理布局各級(jí)牽伸倍數(shù)，按照年產(chǎn)量計(jì)算最大牽伸旦數(shù)，最大牽伸力；按照牽伸力求出第三牽伸機(jī)輥筒的受力情況，依據(jù)最大輥筒受力來(lái)對(duì)輥筒進(jìn)行強(qiáng)度、剛度校核，及其螺釘?shù)男：?。根?jù)受力情況對(duì)牽伸輥和牽伸軸進(jìn)行結(jié)構(gòu)設(shè)計(jì)，要求結(jié)構(gòu)簡(jiǎn)單、加工方便、經(jīng)濟(jì)可行。牽伸輥的聯(lián)接的方式采用法蘭聯(lián)接，比內(nèi)夾套聯(lián)接結(jié)構(gòu)簡(jiǎn)單、裝配方便。合理設(shè)計(jì)通水牽伸輥部件，利用分配板使進(jìn)水和出水流量均勻，充分帶走熱量。參照現(xiàn)有的七輥牽伸機(jī)設(shè)備，設(shè)計(jì)出滿足工作要求的牽伸輥，以達(dá)到大容量生產(chǎn)滌綸短纖維的目的，滿足現(xiàn)代高速紡織機(jī)械的發(fā)展。AbstractPolyester staple aftertreatment equipment 7-roller drawing machines rollers are work part of the drawing machine. And the performance of 7-roller drawing machine will be improved if its correctly designed. The drawing machine is one of the main equipments in the filature aftertreatment. According to the filature processing requirement we can decide the number and power of the drawing machine. This 7-roller drawing machine design is to enhance the annual output. Taking the drawing machine group as an organic whole design, through the total drawing multiple properly distributing each class drawing multiple, according to the annual output calculating the maximal drawing denier and maximal drawing tension, then on the basis of the drawing tension figuring out the force of third drawing machine roller, and according to the maximal roller force checking the intensity and rigidity and proofing the bolt.On the basis of the rollers force designing the frames of the drawing rollers and drawing shafts, which require simple frames, convenient manufacturing, economical and feasible. The link method of the drawing roller adopts flanges, which compares with the inner sleeve link has simple structure, convenient assemblage. Correctly designing the watering drawing roller parts, using the distributing board making the in water and out water equably flowing, and taking out the heat. Consulting the existent 7-roller drawing machine equipments, designing drawing rollers which satisfy the work requirement, and reach the objective of a large amount of polyester staple are produced, meet contemporary high-speed textile mechanical development.II邵 陽(yáng) 學(xué) 院畢業(yè)設(shè)計(jì)(論文)課 題 名 稱 滌綸短纖后處理設(shè)備七輥牽伸機(jī)的牽伸輥設(shè)計(jì) 學(xué) 生 姓 名 文 藝 苑 學(xué) 號(hào) 0241118057 院(系)、專業(yè) 機(jī)械與能源工程系 02機(jī)制本科 指 導(dǎo) 教 師 姜 宏 陽(yáng) 職 稱 高級(jí)工程師 2006年 06 月 2 日邵 陽(yáng) 學(xué) 院畢業(yè)設(shè)計(jì)（論文）開(kāi)題報(bào)告書(shū)課題名稱 滌綸短纖后置處理設(shè)備七輥牽伸機(jī)的牽伸輥設(shè)計(jì) 學(xué)生姓名 文 藝 苑 學(xué) 號(hào) 0241118057 院（系）、專業(yè) 機(jī)械與能源工程系 02機(jī)制本科 指導(dǎo)教師 姜 宏 陽(yáng) 2006年 2 月 28 日一、 課題的來(lái)源、目的意義（包括應(yīng)用前景）、國(guó)內(nèi)外現(xiàn)狀及水平課題來(lái)源：本課題來(lái)源于邵陽(yáng)紡織機(jī)械有限公司。據(jù)中國(guó)紡織報(bào)報(bào)道，滌綸在強(qiáng)力、耐磨等性能上明顯超過(guò)人造纖維和天然纖維，表現(xiàn)出巨大的市場(chǎng)需求和增長(zhǎng)空間，再加上生產(chǎn)流程較短，成本較低，使我國(guó)迅速成為世界上滌綸產(chǎn)量最大的國(guó)家。2005年，我國(guó)化學(xué)纖維產(chǎn)量達(dá)1424萬(wàn)噸，比2003年增長(zhǎng)20%，產(chǎn)量居世界之首，年增幅比世界平均增幅高出13個(gè)百分點(diǎn)，成就喜人。中國(guó)化纖協(xié)會(huì)預(yù)計(jì)，2003年我國(guó)滌綸產(chǎn)量可占化纖產(chǎn)量的79%，到2010年滌綸在紡織纖維總量中的比重可能提高到50%左右。市場(chǎng)拉動(dòng)了化纖產(chǎn)品的迅速增加，化纖產(chǎn)品的生產(chǎn)促進(jìn)了化纖機(jī)械的發(fā)展。牽伸機(jī)是滌綸短纖后置處理設(shè)備之一。目的意義：目前國(guó)際上滌綸短纖維大型成套裝置的單線產(chǎn)能最高為年產(chǎn)5萬(wàn)噸，攻克此技術(shù)已成為各國(guó)權(quán)威專家和各大生產(chǎn)廠家的目標(biāo)。一項(xiàng)滌綸短纖維重大科技攻關(guān)項(xiàng)目年產(chǎn)6萬(wàn)噸成套滌綸短纖維工程技術(shù)開(kāi)發(fā)項(xiàng)目，經(jīng)過(guò)6個(gè)月的精心準(zhǔn)備和試驗(yàn)，7月7日在上海石化公司獲得突破性進(jìn)展，其攻關(guān)的核心技術(shù)中心吹風(fēng)的絲束準(zhǔn)確成型技術(shù)達(dá)到了預(yù)期目標(biāo)。此試驗(yàn)成功，標(biāo)志著我國(guó)滌綸短纖維大型成套生產(chǎn)技術(shù)在國(guó)際上處于領(lǐng)先地位。我國(guó)年產(chǎn)6萬(wàn)噸短纖維國(guó)產(chǎn)化工程技術(shù)和軟件包項(xiàng)目是以技術(shù)開(kāi)發(fā)為主。中心吹風(fēng)的絲束冷卻成型技術(shù)是年產(chǎn)6萬(wàn)噸短纖維成套生產(chǎn)技術(shù)中的核心，全套技術(shù)設(shè)備國(guó)產(chǎn)化率達(dá)到80%，大大降低了投資，帶來(lái)可貴的經(jīng)濟(jì)效益和社會(huì)效益。國(guó)內(nèi)外現(xiàn)狀及水平：國(guó)產(chǎn)長(zhǎng)絲紡絲與后置處理設(shè)備已經(jīng)比較成熟，大量占有國(guó)內(nèi)市場(chǎng)。年產(chǎn)3萬(wàn)噸的滌綸短纖紡絲及后處理成套設(shè)備已供國(guó)內(nèi)70多條線并投入生產(chǎn)，成套出口到國(guó)際市場(chǎng)上的項(xiàng)目也陸續(xù)投產(chǎn)，贏得了好評(píng)。年產(chǎn)5萬(wàn)噸的滌綸短纖成套設(shè)備國(guó)內(nèi)建設(shè)項(xiàng)目已經(jīng)安裝完畢，近期即將投入生產(chǎn)。年產(chǎn)6萬(wàn)噸的成套設(shè)備正在現(xiàn)場(chǎng)安裝近期也將投產(chǎn)。二、 課題研究的主要內(nèi)容、研究方法或工程技術(shù)方案和準(zhǔn)備采取的措施課題研究主要內(nèi)容：1. 完成3000單詞以上與畢業(yè)設(shè)計(jì)有關(guān)的英文資料翻譯（打印稿），譯文要求準(zhǔn)確，文字流暢2. 了解滌綸后處理加工工藝3. 根據(jù)滌綸短纖的年產(chǎn)量，計(jì)算牽伸力，確定牽伸軸及牽伸輥的尺寸4. 完成牽伸輥的結(jié)構(gòu)設(shè)計(jì)，畫(huà)出整裝配圖及零件圖5. 撰寫(xiě)說(shuō)明書(shū)（打印稿），格式和內(nèi)容符合邵陽(yáng)學(xué)院的統(tǒng)一格式和規(guī)范要求研究方法或工程技術(shù)方案：1. 工作運(yùn)動(dòng)分析2. 部件聯(lián)結(jié)方式3. 產(chǎn)品結(jié)構(gòu)設(shè)計(jì)準(zhǔn)備采取的措施：1. 進(jìn)入邵陽(yáng)紡織機(jī)械有限公司對(duì)該牽伸機(jī)進(jìn)行調(diào)研2. 搜索和統(tǒng)計(jì)相關(guān)資料和數(shù)據(jù)3. 結(jié)合邵陽(yáng)紡織機(jī)械有限公司的實(shí)際零件進(jìn)行分析4. 完成七輥牽伸機(jī)輥筒設(shè)計(jì)三、現(xiàn)有基礎(chǔ)和具備的條件現(xiàn)有的基礎(chǔ)：通過(guò)四年的理論學(xué)習(xí)和幾次課程設(shè)計(jì)及多次工廠實(shí)地參觀，我對(duì)機(jī)械設(shè)計(jì)的設(shè)計(jì)內(nèi)容、設(shè)計(jì)方法和設(shè)計(jì)步驟有了一定的了解，掌握了機(jī)械設(shè)計(jì)設(shè)計(jì)的基本知識(shí)，如設(shè)計(jì)計(jì)算、工程繪圖、查閱資料和手冊(cè)，熟悉標(biāo)準(zhǔn)和規(guī)范等，有一定的獨(dú)立工作能力。具備的條件：1. 專業(yè)資深指導(dǎo)老師一位2. 設(shè)計(jì)數(shù)據(jù)一份3. 個(gè)人電腦一臺(tái)4. AutoCAD2004設(shè)計(jì)軟件 5. WORD辦公軟件 6. 圖書(shū)館有關(guān)資料四、總的工作任務(wù)，進(jìn)度安排以及預(yù)期結(jié)果總的工作任務(wù)：應(yīng)用自己所學(xué)的理論知識(shí)，結(jié)合自己掌握的資料，在指導(dǎo)老師的指導(dǎo)和同學(xué)討論確定牽伸機(jī)輥筒的設(shè)計(jì)方案，完成設(shè)計(jì)計(jì)算，繪出零件圖、裝配圖，編寫(xiě)一份說(shuō)明書(shū)，準(zhǔn)備答辯。進(jìn)度安排：1. 2月20日3月10日，熟悉課題，進(jìn)行調(diào)研、收集資料、方案擬訂2. 3月11日4月21日，計(jì)算、分析、編寫(xiě)說(shuō)明書(shū)3. 4月22日5月21日，完成圖紙，修改說(shuō)明書(shū)、刻錄光盤(pán)4. 5月22日 6月10日，準(zhǔn)備答辯五、指導(dǎo)教師審查意見(jiàn)指導(dǎo)教師（簽名） 年 月 日 六、教研室審查意見(jiàn)教研室主任（簽名） 年 月 日 七、院（系）審查意見(jiàn)院（系）主任（簽名） 年 月 日 備 注 邵陽(yáng)學(xué)院畢業(yè)設(shè)計(jì)（論文）目錄前言11 概述21.1 拉伸的目的和作用21.2 牽伸機(jī)組原理22 設(shè)計(jì)參數(shù)的確定42.1 年產(chǎn)2萬(wàn)噸滌綸短纖后處理工藝流程42.2 設(shè)計(jì)基礎(chǔ)42.3確定牽伸旦數(shù)D53 牽伸機(jī)構(gòu)受力分析54 第三牽伸機(jī)功率估算65 七輥牽伸機(jī)的整體分析85.1 第一牽伸機(jī)設(shè)計(jì)85.2 第二牽伸機(jī)設(shè)計(jì)95.3 第三牽伸機(jī)設(shè)計(jì)106 牽伸輥受力分析117 牽伸輥筒的設(shè)計(jì)168 法蘭聯(lián)接螺釘性能等級(jí)和材料確定189 通水牽伸軸設(shè)計(jì)2010 牽伸輥的校核計(jì)算2510.1 強(qiáng)度計(jì)算2510.2 撓度計(jì)算2611 潤(rùn)滑方式與密封裝置28總結(jié)30參考文獻(xiàn)31致謝32附表133附表234附表335邵陽(yáng)學(xué)院畢業(yè)設(shè)計(jì)（論文）進(jìn)度考核表設(shè)計(jì)（論文）課題 滌綸短纖后處理設(shè)備七輥牽伸機(jī)的牽伸輥設(shè)計(jì)院（系） 機(jī)械與能源工程系 年級(jí)專業(yè) 02機(jī)制本科 學(xué)生姓名 文藝苑 學(xué)號(hào) 0241118057 指導(dǎo)教師 姜宏陽(yáng) 起止日期畢業(yè)設(shè)計(jì)（論文）各階段工作任務(wù)完成情況指導(dǎo)教師簽字2.203.10熟悉課題，收集資料3.113.20擬訂設(shè)計(jì)方案3.213.31進(jìn)行總體分析計(jì)算，確定基本結(jié)構(gòu)4.14.5牽伸輥受力分析4.64.10牽伸輥筒的設(shè)計(jì)4.114.15通水牽伸軸設(shè)計(jì)4.164.18潤(rùn)滑方式與密封裝置4.195.10繪畫(huà)圖紙5.115.25撰寫(xiě)設(shè)計(jì)計(jì)算說(shuō)明書(shū)5.265.31修改計(jì)算說(shuō)明書(shū)6.16.4說(shuō)明書(shū)排版6.56.8準(zhǔn)備答辯備注注：本表用于考核學(xué)生畢業(yè)設(shè)計(jì)（論文）的進(jìn)度及完成情況，是學(xué)生畢業(yè)答辯資格認(rèn)定和成績(jī)?cè)u(píng)定的依據(jù)之一。12邵陽(yáng)學(xué)院畢業(yè)設(shè)計(jì)（論文）On the profile design of transmission splines and keysDaniel C.H. Yang, Shih-Hsi Tong Abstract: Splines and keys are machinery components placed at the interface between shafts and hubs of power-transmitting elements. A spline (or key) is usually machined (or attached) onto the shaft of a power-transmitting pair, and the corresponding groove is cut into the hub. The influence of spline profiles on the performance of power transmission is investigated in this paper. The optimal design of spline profiles for three different design criteria is presented. The method of calculus of variation is used to determine profile functions for maximum value. Analytical results are successfully obtained. They show that the splines with involute profiles lead to uniform deformation on the hub, in addition they can carry the maximum transmission load capacity. On the other hand, radial straight profiles result in optimum transmission efficiency. We think that these findings are worthy reporting and also believe that this approach could be used for the spline design with other performance criteria imposed.Keywords: Splines; Keys1 IntroductionA key is a machinery component placed at the interface between a shaft and the hub of a power-transmitting element such as gear and sprocket . A spline performs the same function as a key in transmitting torque from the shaft to the mating element . The main difference between splines and keys is that splines are integral with the shaft but keys are inserted between shaft and hub. As compared with one or two keys used for load transmission, there are usually four or more splines on a shaft. Therefore, the transmission torque is more uniform and the loading for each spline is lower. Splines play an important role in transmitting torque and their profiles do have the influence on the performance of power transmission. Unlike the conjugate profiles, the shaft with splines and hub have the same rotation axis and they are in surface contact without relative motion, they are connected together and have the same angular velocity. Therefore, it seems that any profiles except the shaft surface can be used for the design of splines. However, the load between the spline and hub is not evenly distributed over the entire contact surface in practice. The load may always concentrate on a small portion of contact surface and deformthe hub surface. This results in undesired clearance between the shaft and hub and will lead to serious damage of hub surface as the working cycles increase. To solve these problems, how the profiles of splines affect the torque transmission needs to be further investigated to find out the suitable design of spline profiles.Currently there are two main types of splines used, namely, straight-sided and involute splines. The involute splines provide the mating element with self-centering and can be machined with standard hob cutter used to cut gear teeth. To date, the related research work focuses on conjugate profiles and gear design as well as the design of profile curvatures for reducing the wear of contact surfaces. However, none of them can be applied to the profiles of splines directly due to different working conditions. Also, there is no research work on how to design spline profiles under given requirements. In this paper, the basic equations for spline profiles are established and used to synthesize desired profiles for different design objectives. Three design objectives, uniform deformation, maximum torque transmission, and optimum efficiency, are used to determine spline profiles. Analytical solutions are successfully obtained.2 Problem description and basic assumptionsAs shown in fig .1, The hub is driven by the shaft and the spline is fixed on the shaft. The radius of the shaft, the height of the spline, and the number of spline teeth are determined by the design requirements and cannot be altered. Only the spline profile can be modified to improve the performance of transmission. To simplify the design problem for analysis, the following assumptions were made:(1) The spline is a rigid body.Compared with the hub, the spline is made of hard material and assumed no deformation after applying the load.(2) The hub is under elastic deformationThe surface deformation of the hub is within the range of elasticity and the surface stress is proportional to the normal deformation.(3) There is no beam deformation on the spline.For spline keys, usually the height of tooth shape is small relative to its width. Therefore, we assume there is no accumulated deformation at the free end. The only deformation is the normal deformation on the hub surface.(4) There is no clearance between the spline and hub when they are in contact. (Surface contact)The profile of the spline is exactly the same as that of the hub without considering manufacturing errors. They are in surface contact without clearance.3 Spline profile for uniform hub deformationThe first design objective is to have the uniform deformation on the surface of the hub, which also implies the uniform stress on the hub. This design can ensure the surface stress is evenly distributed and avoid the failure of material at some weak points. Referring to fig.2, Let denote the radius of shaft and denote a small rotation angle of spline. Since we assume that the spline is a rigid body, the change between two spline positions will be the deformation of the hub. 4 Its simply to confirmed the dangerous sections Prerequisite that traditional design method considered whether pair influence part design variable of working state, for instance stress , intensity , safety coefficient , load , environmental factor , material performance , part size and structural factor ,etc., deal with the single value variable confirmed. Describe part mathematical model of state , i.e. variable and relation of variable , to go on single value vary and win the dangerous section through deterministic function.There are several methods that usually the dangerous sections are determined: 4.1 Minimum diameter of the spline Spline dangerous sectional reliability very getting high, this to confirm according to traditional design experience because of diameter of spline. If require appropriate reliability value, then the diameter of the axle can select smaller value for use .4.2 Safety coefficient law of dependability While adopting the safety coefficient law design of dependability , must know the distribution types of stress and intensity and be distributed estimated value of the parameter . And the accumulation of dependability data is a long-term job, therefore we must utilize the existing data materials , it is (such as the terminal theorem in the centre and 3 rules to use relevant theorems and rule ), to confirm the distribution types of a lot of random variables involved of design process and is distributed the parameter. In the safety coefficient of dependability is calculated , deal with all design parameters involved a random variable, link the concept of safety coefficient to concept of dependability , thus set up corresponding probability model. Because of considering the uncertainty (randomness ) of the phenomenon taking place in project reality and sign parameter, therefore can announce the original appearances of the things even more. Theory analysis and practice indicate , the dependability design is designed more than traditional machinery , can punish some problem of the design , raise product quality , reduce part size effective, thus save the raw materials , lower costs .5 Concluding remarksThe mechanical reliability design is one kind of modern design theory and the method which in the recent several dozens years develop, it take improves the product quality as the core, take the theory of probability, the mathematical statistic as the foundation, synthesizes using the engineering mechanics, the system engineering, the operations research and so on the multi-disciplinary knowledge studies the mechanical engineering most superior design question. At present, the reliability design theory tended to the consummation, but uses in the machine parts design project actual very being actually few truly. When uses the reliable security method of correlates design, must know the stress and the intensity distributed type and the distributed parameter estimated value. But the reliable data accumulation also is a long-term work, thus we must use the existing data material, the utilization related theorem and the principle, determined in the design process involves many random variable distributed types and distributed parameter. In this paper the optimal design of spline (or key) profiles for three different design criteria is presented. The method of calculus of variation is used to determine profile functions for maximum value. Analytical results are successfully obtained. It shows that the splines with involute profiles lead to uniform deformation on the hub, in addition they can carry the maximum transmission load capacity. On the other hand radial straight profiles result in optimum transmission efficiency. We believe similar approach could be used to determine other spline profiles when new performance criteria are imposed.References1 Robert L. Mott, Machine Elements in Mechanical Design, third ed., Prentice-Hall Inc., 1999.2 M.F. Spotts, Design of Machine Elements, third ed., Prentice-Hall Inc., 1961.3 Joseph E. Shigley, Larry D. Mitchell, Mechanical Engineering Design, fourth ed., McGraw-Hill Inc., 1983.4 D.C.H. Yang, S.H. Tong, J. Lin, Deviation-function based pitch curve modification for conjugate pair design, Transaction of ASME Journal of Mechanical Design 121 (4) (1999) 579586.5 S.H. Tong, New conjugate pair designtheory and application, PhD Dissertation, Mechanical and Aerospace Engineering Department, UCLA, 1998.6 F.L. Litvin, Gear Geometry and Applied Theory, Prentice-Hall Inc., 1994.7 D.B. Dooner, A.A. Seireg, The Kinematic Geometry of Gearing, John Wiley & Sons Inc., 1995, pp. 5663.8 Y. Ariga, S. Nagata, Load capacity of a new WN gear with basic rack of combined circular and involute profile, Transaction of ASME Journal of Mechanisms, Transmissions, and Automation in Design 107 (1985) 565572.9 M.J. French, Gear conformity and load capacity, in: Proc Instn Mech Engrs, vol. 180(43), Pt 1, (196566), pp. 10131024.10 A.O. Lebeck, E.I. Radzimovsky, The synthesis of tooth profile shapes and spur gears of high load capacity, Transaction of ASME Journal of Engineering for Industry (1970) 543553.11 H. Iyoi, S. Ishimura, v-Theory in gear geometry, Transaction of ASME Journal of Mechanisms, Transmissions, and Automation in Design 105 (1983) 286290.12 J.E. Beard, D.W. Yannitell, G.R. Pennock, The effects of the generating pin size and placement on the curvature and displacement of epitrochoidal gerotors, Mechanism and Machine Theory 27 (4) (1992) 373389.13 H.C. Liu, S.H. Tong, D.C.H. Yang, Trapping-free rotors for high sealing lobe pumps, Transaction of ASME Journal of Mechanical Design 122 (4) (2000) 536542.14 Charles Fox, Calculus of Variations, Oxford University Press, 1954.ARTICLE IN PRESS7