傳動軸式自行車的設(shè)計【說明書+CAD+SOLIDWORKS+仿真】

傳動軸式自行車的設(shè)計【說明書+CAD+SOLIDWORKS+仿真】,說明書+CAD+SOLIDWORKS+仿真,傳動軸式自行車的設(shè)計【說明書+CAD+SOLIDWORKS+仿真】,傳動軸,自行車,設(shè)計,說明書,仿單,cad,solidworks,仿真 傳動軸式自行車的設(shè)計1.傳動方案初步確定傳動方案的確定圖1-1傳動方案的確定該方案和普通鏈傳動相比較有傳動效率高，減少了鏈條式自行車因為布局不好所帶來的對衣服咬合所帶來的危險，也減少了鏈傳動多邊形效應(yīng)對功率的損失和震動噪音等產(chǎn)生，不會再出現(xiàn)關(guān)鍵時刻掉鏈子的可能，但是由于該傳動有錐齒輪和傳動軸組成帶來的問題便是加工困難和成本較高。2.傳動的結(jié)構(gòu)設(shè)計2.1動力和轉(zhuǎn)速確定一般腳踏以 60r/min 節(jié)奏轉(zhuǎn)動較為合適一般人能給自行車的轉(zhuǎn)矩在T=13000左右2.2 圓錐齒輪傳動設(shè)計2.2.1前部錐齒輪設(shè)計按齒面強度設(shè)計計算大端分度圓直徑d1選用直齒圓錐齒輪傳動，選用直齒圓錐齒輪傳動，自行車為一般工作機器，速度低故選用8 級精度。機械設(shè)計表10-1 查得：選擇小齒輪材料為40Cr（調(diào)質(zhì)），硬度為250HBS；大齒輪材料為45 鋼（調(diào)質(zhì)），硬度為200HBS，兩者材料硬度差為50HBS。選小齒輪齒數(shù)Z1=17 ， 大齒輪齒數(shù)Z2=17/0.6=28.3，取Z2=29計算大端分度圓直徑根據(jù)參考機械設(shè)計227頁公式10-26估計V11m/s，并取8 級精度等級。由機械設(shè)計194 頁圖10-8 查得： =1.05由機械設(shè)計226 頁表10-9 查得：=1.00而=1.5=1.51.00=1.5取=1.0由機械設(shè)計193 頁表10-2 查得：=1.00故動載系數(shù)K=1.001.051.51.00=1.575由機械設(shè)計201 頁表10-6 查得：=189.8并取=由機械設(shè)計209 頁圖10-21d 查得齒輪1 和2 的接觸疲勞強度極限分別為：=600 =550齒輪1 和2 的工作應(yīng)力循環(huán)次數(shù)分別為：=60600.6530010=3.2410由機械設(shè)計207 頁圖10-19 查得：=1.0 =1.2取S=1故許用應(yīng)力：=600=660應(yīng)取兩者中的較小者，故600根機械設(shè)計227 頁式10-26有萬方數(shù)據(jù)相關(guān)資料查的T=13475左右?guī)霐?shù)據(jù)與估計無太大差異。分錐角齒寬取齒寬b=20mm。大端模數(shù)取m=3.25大齒輪分度圓=3.2529=94.25mm小齒輪分度圓=3.2517=55.25mm錐距 mm按齒根彎曲強度設(shè)計由機械設(shè)計226 頁式10-23 知：由機械設(shè)計200 頁表10-5，查取齒形系數(shù)校正系數(shù)2.97 2.531.52 1.62由機械設(shè)計208 頁圖10-20（c）得：=550=510由機械設(shè)計206 頁圖10-18 得：=0.85 =0.87取彎曲安全系數(shù)S=1.4=334 =317計算大小齒輪的并加以比較：=0.0135=0.0129小齒輪的數(shù)值大。=1 1.05 1 1.5=1.575=2.054可見，由齒面疲勞強度計算而得的模數(shù)m 大于由齒根彎曲疲勞強度計算的模數(shù)，由于齒輪模數(shù)m 的大小主要取決于彎曲強度所決定的承載能力，而齒面接觸疲勞強度所決定的承載能力僅與齒輪直徑有關(guān)，選取齒面接觸的疲勞強度3.0094，取標(biāo)準(zhǔn)值m=3.25最終效果圖如下圖2-1錐齒輪1和錐齒輪22.2.2 尾部錐齒輪的設(shè)計按齒面強度設(shè)計計算大端分度圓直徑d1選用直齒圓錐齒輪傳動，選用直齒圓錐齒輪傳動，自行車為一般工作機器，速度低故選用8 級精度。機械設(shè)計表10-1 查得：選擇小齒輪材料為40Cr（調(diào)質(zhì)），硬度為250HBS；大齒輪材料為45 鋼（調(diào)質(zhì)），硬度為200HBS，兩者材料硬度差為50HBS。選小齒輪齒數(shù)Z3=17 ， 大齒輪齒數(shù)Z4=17/0.8=21.25，取Z4=22計算大端分度圓直徑根據(jù)參考機械設(shè)計227頁公式10-26估計V11m/s，并取8 級精度等級。由機械設(shè)計194 頁圖10-8 查得： =1.05由機械設(shè)計226 頁表10-9 查得：=1.00而=1.5=1.51.00=1.5取=1.0由機械設(shè)計193 頁表10-2 查得：=1.00故動載系數(shù)K=1.001.051.51.00=1.575由機械設(shè)計201 頁表10-6 查得：=189.8并取=由機械設(shè)計209 頁圖10-21d 查得齒輪1 和2 的接觸疲勞強度極限分別為：=600 =550齒輪1 和2 的工作應(yīng)力循環(huán)次數(shù)分別為：=60530010=9.010由機械設(shè)計207 頁圖10-19 查得：=0.97 =0.99取S=1，故許用應(yīng)力：=582=544.5應(yīng)取兩者中的較小者，故544.5根機械設(shè)計227 頁式10-26代入數(shù)據(jù)計算得與估計無太大差異。分錐角齒寬取齒寬b=15mm。大端模數(shù)取m=3.5大齒輪分度圓=3.522=77mm小齒輪分度圓=3.517=59.5mm錐距 mm按齒根彎曲強度設(shè)計由機械設(shè)計226 頁式10-23 知：由機械設(shè)計200 頁表10-5，查取齒形系數(shù)校正系數(shù)2.97 2.721.52 1.57由機械設(shè)計208 頁圖10-20（c）得：=550=510由機械設(shè)計206 頁圖10-18 得：=0.85 =0.87取彎曲安全系數(shù)S=1.4=334 =317計算大小齒輪的并加以比較：=0.0135=0.0134小齒輪的數(shù)值大。=1 1.05 1 1.5=1.575=2.53可見，由齒面疲勞強度計算而得的模數(shù)m 大于由齒根彎曲疲勞強度計算的模數(shù)，由于齒輪模數(shù)m 的大小主要取決于彎曲強度所決定的承載能力，而齒面接觸疲勞強度所決定的承載能力僅與齒輪直徑有關(guān)，選取齒面接觸的疲勞強度3.44，取標(biāo)準(zhǔn)值m=3.5最終效果圖圖2-2 齒輪3和錐齒輪42.3對軸的初步設(shè)計 2.3.1對軸1的設(shè)計已知條件，軸1轉(zhuǎn)矩T1=1347N mm選軸的材料，因為傳遞的功率不大，并對重量及結(jié)構(gòu)尺寸無特殊要求，故有機械設(shè)計362頁表15-1選用常用材料45鋼，調(diào)制處理。初步計算軸頸由機械設(shè)計表15-3得=103-126。取=110.則軸的直徑即為公式中取=60r/min所以=0.085kw所以=12.35mm選用深溝球軸承選擇代號為6003，由機械設(shè)計332頁表13-10，由于速度不大故采用脂潤滑。初步對軸整體設(shè)計預(yù)選6003查手冊得：d=17 D=35 B=10取軸承端面到殼體內(nèi)壁距離為2mm，齒輪到殼體內(nèi)壁為10，兩端軸d勁=17部分長度為：=10+2=12裝齒輪2的寬度預(yù)選30l=30-2=28軸環(huán)寬度B=5 d=20 h=200.07+2=3.4 取3.5另外還有與腳蹬相連接的部分，又對現(xiàn)有自行車的軸參考選軸總長為200.軸向定位中間軸環(huán)，彈性卡簧，軸套等零件。4軸上零件的周向定位選用健配合齒輪2健 bh=66軸承內(nèi)圈與軸過盈配合軸表面粗糙度0.8軸承外圈與殼體間隙配合殼體表面粗糙度1.65軸的工藝要求或表面配合表面粗糙度3.2，其余12.5，軸端倒145圖2-3軸1軸的強度校核由于該軸為轉(zhuǎn)軸，應(yīng)按彎扭組合強度進行校核計算。圖2-4 受力分析根據(jù)受力分析，齒輪所受的轉(zhuǎn)矩：T2=13.5Nm齒輪作用力：Ft=2T2/ dm2=286N Fr= Fttancos1=80.1N Fa= Fttansin1=46.8N求支反力Rv1=49.2NRv2= Rv1-Fr=49.2-80.1=-30.9NRH1= RH2=143N求C點彎矩MV1= Rv2L2=-30.928=-865.2NmmMV2= MVC1+Fa= -865.2+46.8=1340.25NmmMHC=RH2L2=14328=4004Nmm圖2-5 軸1彎矩繪制扭矩圖（g）T2=13.5Nm計算合成彎矩MC1=4096.4NmmMC2=4222.35Nmm繪制扭矩圖（h）圖2-5扭矩圖軸的材料為45鋼，調(diào)質(zhì)處理，-1=2545Mpa.從總當(dāng)量彎矩圖可以看出，截面C為危險截面。截面C為齒輪處，dC=20mm，則bC=8.4Mpa-1，軸的強度足夠。2.3.2 軸2設(shè)計選軸的材料，因為傳遞的功率不大，并對重量及結(jié)構(gòu)尺寸無特殊要求，故有機械設(shè)計362頁表15-1選用常用材料45鋼，調(diào)制處理。初步計算軸頸由機械設(shè)計表15-3得=103-126。取=110.則軸的直徑即為傳遞的功率=0.97=0.082kw n=60/0.6=100r/min帶入數(shù)據(jù)得所以=10.30mm選用深溝球軸承選擇代號為6002，由機械設(shè)計332頁表13-10，由于速度不大故采用脂潤滑。初步對軸整體設(shè)計預(yù)選6002查手冊得：d=15 D=32 B=9擬定裝配方案：齒輪 軸套 軸承端蓋，選用健配合齒輪2健 bh=55軸承內(nèi)圈與軸過盈配合軸表面粗糙度0.8軸承外圈與殼體間隙配合殼體表面粗糙度1.65軸的工藝要求或表面配合表面粗糙度3.2，其余12.5，軸端倒145.和萬向節(jié)連接處最小取最小直徑12，圖2-6 軸2軸的強度校核由于該軸為轉(zhuǎn)軸，應(yīng)按彎扭組合強度進行校核計算。圖2-7 受力分析根據(jù)受力分析，齒輪所受的轉(zhuǎn)矩：T2=8.11Nm齒輪作用力：Ft=2T2/ dm2=294.9N Fr= Fttancos1=82.67N Fa= Fttansin1=48.45N求支反力Rv1=74.79NRv2= Rv1-Fr=74.79-82.67=-7.8NRH1= RH2=147.45N2）求A點彎矩MV1= Rv2L2=-7.840=-312NmmMV2= MVC1+Fa= -312+48.45=1027.8NmmMHC=RH2L2=147.4540=5898NmmT2=8.11Nm計算合成彎矩MC1=5906.24NmmMC2=5986.88Nmm軸的材料為45鋼，調(diào)質(zhì)處理，-1=2545Mpa.從以上分析可以看出，截面A為危險截面。截面A為齒輪處，dA=20mm，則bC=8.25 Mpa-1，軸的強度足夠。2.3.3軸3設(shè)計選軸的材料，因為傳遞的功率不大，并對重量及結(jié)構(gòu)尺寸無特殊要求，故有機械設(shè)計362頁表15-1選用常用材料45鋼，調(diào)制處理。初步計算軸頸由機械設(shè)計表15-3得=103-126。取=110.則軸的直徑即為傳遞的功率為=0.98=0.0803 n=100r/min代入數(shù)據(jù)得=10.22mm選用深溝球軸承選擇代號為6002，由機械設(shè)計332頁表13-10，由于速度不大故采用脂潤滑。初步對軸整體設(shè)計預(yù)選6002查手冊得：d=15 D=32 B=9擬定裝配方案：齒輪 軸套 軸承端蓋，選用健配合齒輪2健 bh=55軸承內(nèi)圈與軸過盈配合軸表面粗糙度0.8軸承外圈與殼體間隙配合殼體表面粗糙度1.65軸的工藝要求或表面配合表面粗糙度3.2，其余12.5，軸端倒145.和萬向節(jié)連接處最小取最小直徑12，圖2-8 軸3軸的強度校核由于該軸為轉(zhuǎn)軸，應(yīng)按彎扭組合強度進行校核計算。圖2-9 受力分析根據(jù)受力分析，齒輪所受的轉(zhuǎn)矩：T2=7.92Nm齒輪作用力：Ft=2T2/ dm2=205.17N Fr= Fttancos1=52.73N Fa= Fttansin1=40.77N求支反力Rv1=65.6NRv2= Rv1-Fr=65.6-52.73=12.87NRH1= RH2=102.58N求A點彎矩MV1= Rv2L2=12.8740=514.8NmmMV2= MVC1+Fa= 514.8+40.77=2084NmmMHC=RH2L2=102.5840=4103.2NmmT2=7.92Nm計算合成彎矩MC1=4135NmmMC2=4602Nmm軸的材料為45鋼，調(diào)質(zhì)處理，-1=2545Mpa.從以上分析可以看出，截面A為危險截面。截面A為齒輪處，dA=20mm，則bC=8.08 Mpa-1，軸的強度足夠。2.4傳動軸設(shè)計由機械設(shè)計公式15-3材料選擇45鋼 取=0.5 =110 P=0.82kw n=100代入數(shù)據(jù)計算得 10.51mm為了滿足強度要求=12mm =6mm設(shè)作用于十字軸軸頸中點的力為F，則=851.984N十字軸軸頸根部的彎曲應(yīng)力w和切應(yīng)力應(yīng)滿足w=w=式中，取十字軸軸頸直徑d1=6mm，十字軸油道孔直徑d2=3mm，合力F作用線到軸頸根部的距離s=2.5mm，w為彎曲應(yīng)力的許用值，為250-350Mpa，為切應(yīng)力的許用值，為80-120 Mpaw=107Mpaw= = =40 Mpa故十字軸軸頸根部的彎曲應(yīng)力和切應(yīng)力滿足校核條件十字軸效果圖如下圖2-10 十字軸萬向節(jié)十字軸滾針的接觸應(yīng)力應(yīng)滿足j=272j式中，取滾針直徑d0=2mm，滾針工作長度Lb=5mm，在合力F作用下一個滾針?biāo)艿淖畲筝d荷Fn= 即 =326.593N當(dāng)滾針和十字軸軸頸表面硬度在58HRC以上時，許用接觸應(yīng)力j為3000-3200 Mpa j=272=1.97 Mpaj故十字軸滾針軸承的接觸應(yīng)力校核滿足傳動軸強度校核按扭轉(zhuǎn)強度條件T=T/WTT式中，T為扭轉(zhuǎn)切應(yīng)力，取軸的轉(zhuǎn)速n=100r/min，軸傳遞的功率P=0.085kw，Dc=12mm，dc=6mm分別為傳動軸的外內(nèi)直徑，根據(jù)機械設(shè)計表15-3得T為25-45 Mpa即=25 MpaT故傳動軸的強度符合要求傳動軸轉(zhuǎn)速校核及安全系數(shù)傳動軸的臨界轉(zhuǎn)速為nk=1.2108式中，取傳動軸的支承長度Lc=400mm, dc=6mm, Dc=12mm分別為傳動軸軸管的內(nèi)外直徑, nmax=100 r/minnk=1.2108=6495r/min6495遠大于100所以軸管臨界轉(zhuǎn)速合格。傳動軸軸管斷面尺寸除應(yīng)滿足臨界轉(zhuǎn)速要求以外，還應(yīng)保證有足夠的扭轉(zhuǎn)強度。軸管的扭轉(zhuǎn)應(yīng)力c=c式中c=300 Mpac=0.544 Mpac軸管的扭轉(zhuǎn)應(yīng)力校核符合要求.對于傳動軸上的花鍵軸，通常以底徑計算其扭轉(zhuǎn)應(yīng)力h，許用應(yīng)力一般按安全系數(shù)2-3確定h = 式中,取花鍵軸的花鍵內(nèi)徑dh=18mm，外徑Dh=22mm,h =11.77 Mpa傳動軸花鍵的齒側(cè)擠壓應(yīng)力y應(yīng)滿足y=T1K/Lhn0y式中,取花鍵轉(zhuǎn)矩分布不均勻系數(shù)K=1.35,花鍵的有效工作長度Lh=40mm，花鍵齒數(shù)n0=6當(dāng)花鍵的齒面硬度大于35HRC時：許用擠壓應(yīng)力y=25-50 Mpay= =31.89Mpa y傳動軸花鍵的齒側(cè)擠壓應(yīng)力y滿足要求傳動軸華健效果圖如下圖2-11 傳動軸花鍵傳動軸最終效果圖如下圖2-12 傳動軸整體圖3. 對自行車局部的改造3.1 對車架改造 以現(xiàn)有的自行車架為基礎(chǔ)對其進行改造以適應(yīng)對傳動軸齒輪箱體的合理布局能夠使傳動軸和自行車架結(jié)合到一體圖3-1 改造后的車架對1處采用圖示的改造，使該處能夠與齒輪箱相連接，對2處的改造如上圖所示，此處的改造是提高原本在底處的車架，為了減少對傳動軸的干擾。3.2對棘輪的改造圖3-2 改造后的棘輪機構(gòu)把原有的最外圈和小鏈輪連接的棘輪機構(gòu)改造成如上圖所示的結(jié)構(gòu)，使其能夠與上圖所示的錐齒輪相配合到一起，實現(xiàn)傳動。最終的自行車裝配圖如下圖3-3總體裝配圖4. 對齒輪箱結(jié)構(gòu)尺寸的設(shè)計機體的結(jié)構(gòu)尺寸機座壁厚=取機座壁厚為8機蓋壁厚取機蓋壁厚為8機座凸緣厚度b=1.5=12機蓋凸緣厚度=1.5=12與車架連接螺栓直徑=取=12軸承旁連接螺栓直徑=9機蓋與機座連接螺栓直徑（0.50.6）=6軸承端蓋螺釘直徑=（0.40.5）=4.8取=5潤滑與密封由于齒輪速度較低選用脂潤滑齒輪選用7407號齒輪潤滑脂，軸承的潤滑采用滾珠軸承潤滑脂，采用氈圈密封。5總結(jié)經(jīng)歷了四年的學(xué)習(xí)，畢業(yè)設(shè)計終于告一段落。這也是在以前學(xué)習(xí)中一直沒有遇到過的，這次畢業(yè)設(shè)計讓我深深體會到了機械設(shè)計的嚴(yán)謹(jǐn)，復(fù)雜，系統(tǒng)性的設(shè)計一個傳動軸自行車完全不像以往設(shè)計一個零件那么簡單，其中一個小錯誤都有可能導(dǎo)致最后傳動軸自行車的設(shè)計錯誤。最終實現(xiàn)對傳動軸自行車的設(shè)計，本設(shè)計的有點改觀了自行車傳動方式，傳動軸自行車能夠更高效率的傳動人的動力，改變了因為鏈傳動所帶來的一些缺點，比如鏈傳動所帶來的對褲子的咬合，有鏈傳動多邊形效應(yīng)帶來的震動和噪音，這種方式的自行車如果在市場推出肯定有不錯的市場一是這種傳動的新穎，最主要還是傳動的效率高在同等條件下的鏈傳動自行車相比較會感覺更省力，通過對自行車的三維建模使我更熟練的掌握使用solidworks和CAD，最后感謝指導(dǎo)老師的辛勤指導(dǎo)使我少走彎路更好的完成我的畢業(yè)設(shè)計。致 謝首先，我要感謝我的指導(dǎo)老師李宜峰老師，他嚴(yán)謹(jǐn)細(xì)致、一絲不茍的作風(fēng)一直是我工作、學(xué)習(xí)中的榜樣，給了起到了指明燈的作用；他們循循善誘的教導(dǎo)和不拘一格的思路給予我無盡的啟迪，讓我很快就感受到了設(shè)計的快樂并融入其中。其次我要感謝同組同學(xué)對我的幫助和指點，沒有他們的幫助和提供資料，沒有他們的鼓勵和加油，這次畢業(yè)設(shè)計就不會如此的順利進行。此次畢業(yè)設(shè)計歷時三個月，是我大學(xué)學(xué)習(xí)中遇到過的時段最長、涉及內(nèi)容最廣、工作量最大的一次設(shè)計。用老師的一句話概括就是這次畢業(yè)設(shè)計相當(dāng)如是把以前的小課程設(shè)計綜合在一起的過程，只要把握住每個小課設(shè)的精華、環(huán)環(huán)緊扣、增強邏輯，那么這次的任務(wù)也就不難了。我此次的任務(wù)是做一個項目的招標(biāo)文件。雖說老師說的話讓此次的畢業(yè)設(shè)計看起來不是那么的可怕，但是當(dāng)我真的開始著手時，還的確是困難重重。俗話說的好，“磨刀不誤砍柴工”，當(dāng)每次遇到不懂得問題時，我都會第一時間記在本子上面，然后等答疑的時候問兩位老師，老師對于我提出來的問題都一一解答，從來都不會因為我的問題稍過簡單加以責(zé)備，而是一再的告誡我做設(shè)計該注意的地方，從課題的選擇到項目的最終完成，老師都始終給予我細(xì)心的指導(dǎo)和不懈的支持，他們真正起到了“傳道授業(yè)解惑疑”的作用，讓人油然而生的敬佩。除此之外，我們組和老師還有另外兩個交流途徑：打電話和上網(wǎng)，為此老師還特意建立一個群，以便大家第一時間接收到畢業(yè)設(shè)計的最新消息和資料，每次大家都在群不亦樂乎的討論著畢業(yè)設(shè)計的事情。多少個日日夜夜，兩位老師不僅在學(xué)業(yè)上給我以精心指導(dǎo)，同時還在思想、生活上給我以無微不至的關(guān)懷，除了敬佩老師們的專業(yè)水平外，他們的治學(xué)嚴(yán)謹(jǐn)和科學(xué)研究的精神也是我永遠學(xué)習(xí)的榜樣，并將積極影響我今后的學(xué)習(xí)和工作。在此謹(jǐn)向xx老師致以誠摯的謝意和崇高的敬意。在論文即將完成之際，我的心情無法平靜，從開始進入課題到論文的順利完成，有多少可敬的師長、同學(xué)、朋友給了我無言的幫助，在這里請接受我誠摯的謝意! 最后我還要感謝機電學(xué)院和我的母校塔里木大學(xué)四年來對我的栽培。參考文獻1孟憲源,姜琪.機構(gòu)構(gòu)型與應(yīng)用M.機械工業(yè)出版社,1966.2吳宗澤,羅圣國.機械設(shè)計課程設(shè)計手冊M.高等教育出版社,1965.3成大先,機械設(shè)計手冊機械傳動M.化學(xué)工業(yè)出版社，1982.4孫桓, 陳作模, 葛文杰.機械原理M.第七版.高等教育出版社，1967.5傳動軸萬向節(jié)安裝M. 實用汽車技術(shù)，2006/036 陳敏 , 劉曉敘.AUTOCAD教程M.機械工業(yè)出版社，1988.7江耕華，胡來瑢，陳啟松 .機械傳動設(shè)計手冊（上冊M）.北京：煤炭工業(yè) 出版社,1982.8成大先 ,機械設(shè)計手冊（單行本） .軸承M, 化學(xué)工業(yè)出版社，1982.9成大先,機械設(shè)計手冊（單行本）M. 機械制圖極限與配合,化學(xué)工業(yè)出版社，201110龔淅義 ,羅圣國 李平林 張立乃 黃少顏 編機械設(shè)計課程設(shè)計指導(dǎo)書（第二版）M .高等教育出版社，1992.11濮良貴 紀(jì)名剛主編. 機械設(shè)計（第七版）M.西北工業(yè)大學(xué)機械原理及機械零件教研室,高等教育出版社，2006.12成大先, 機械設(shè)計手冊（單行本） 軸及其聯(lián)接M, 化學(xué)工業(yè)出版社,1982.13吳宗澤 羅圣國, 機械設(shè)計課程設(shè)計手冊M ,機械工業(yè)出版社,1965.14吳宗澤,機械結(jié)構(gòu)設(shè)計M，北京機械工業(yè)出版社,1989.15 羊拯民主編.傳動軸和萬向節(jié)M.北京：人民交通出版社，198647882412 屆畢業(yè)設(shè)計傳動軸自行車 設(shè)計說明書學(xué)生姓名 郝良慶 學(xué) 號 8011208105 所屬學(xué)院 機械電氣化工程學(xué)院 專 業(yè) 機械設(shè)計制造及其自動化 班 級 機械12-1 指導(dǎo)教師 李宜峰 日 期 2012.5 塔里木大學(xué)教務(wù)處制前 言在科技日益發(fā)達的當(dāng)今社會，新型技術(shù)不斷被研發(fā)并輻射到社會的實際運用中去，隨著人們環(huán)境意識的不斷增強，人們都在尋著能夠省時省力節(jié)能的新型代步工具！都在為共創(chuàng)和諧的節(jié)約型社會而努力！隨著居民生活水平的不斷提高，自行車的使用不僅僅再是普通的代步工具，而逐漸成為人們娛樂、休閑、鍛煉的首選工具。行駛途中，可以當(dāng)做普通自行車騎行鍛煉身體，隨著時間的推移，原始簡單的鏈傳動自行車已不再滿足人們的心里，人們都希望完善自行車的傳動方式功用，以給人們帶來更多的方便。從早期的自行車雛型出現(xiàn)，到今天種類繁多、形式多樣的自行車產(chǎn)品，已經(jīng)歷了近200年的歷史，隨著社會的發(fā)展、技術(shù)的進步、產(chǎn)品的更新、生活節(jié)奏的加快, 人們在享受物質(zhì)生活的同時, 更加注重產(chǎn)品的方便、舒適、可靠、價值、安全、效率等人機性能, 創(chuàng)新設(shè)計即充分發(fā)揮人的創(chuàng)造才能,利用技術(shù)原理進行創(chuàng)新構(gòu)思的設(shè)計實踐活動，其目的是為人類社會提供富有新穎性和先進性的產(chǎn)品.因此，創(chuàng)新設(shè)計的基本特征是新穎性和先進性?！靶路f性”就是設(shè)計者不拘于前人或別人已有的成就,敢于根據(jù)從未嘗試過的想法去進行新的探索,設(shè)計出別具一格的產(chǎn)品?！跋冗M性”就是設(shè)計的產(chǎn)品不僅應(yīng)標(biāo)新立異，而且在技術(shù)水平上比現(xiàn)有的類似產(chǎn)品要超前一步，即在功能、性能、結(jié)構(gòu)等方面顯示出新的特點和實質(zhì)性的改進，創(chuàng)新設(shè)計即充分發(fā)揮人的創(chuàng)造才能，任何一種設(shè)計都離不開創(chuàng)新，工業(yè)設(shè)計領(lǐng)域中,無論是對傳統(tǒng)產(chǎn)品的改進性設(shè)計,還是對新產(chǎn)品的開發(fā)性設(shè)計都需要創(chuàng)新。因此,對自行車進行創(chuàng)新設(shè)計和概念設(shè)計具有重要意義，對傳動軸自行車設(shè)計通過對鏈輪改造，把前鏈輪改造成一對錐齒輪傳動 中間通過傳動軸代替鏈條，后輪在通過一對錐齒輪改變傳動的方向設(shè)計要求由于設(shè)計的水平有限，設(shè)計中難免存在錯誤和不當(dāng)之處，懇請各位老師批評指正。目 錄1. 傳動方案初步確定.12. 傳動的結(jié)構(gòu)設(shè)計.12.1動力和轉(zhuǎn)速確定.12.2 圓錐齒輪傳動設(shè)計.12.2.1前部錐齒輪設(shè)計.12.2.2 尾部錐齒輪的設(shè)計.52.3 對軸的初步設(shè)計.82.3.1對軸1的設(shè)計.82.3.2 對軸2的設(shè)計.122.3.3 對軸3的設(shè)計.142.4傳動軸設(shè)計.16 3. 對自行車局部的改造.203.1 對車架改造.203.2對棘輪的改造204. 對齒輪箱結(jié)構(gòu)尺寸的設(shè)計 . 215.總結(jié).22致謝23參考文獻.24 傳動軸式自行車的設(shè)計郝良慶（塔里木大學(xué)機械電氣化工程學(xué)院， 阿拉爾 843300）摘 要：我國是一個自行車大國，針對傳統(tǒng)鏈傳動自行車出現(xiàn)的一些問題，容易掉鏈，傳動效率地等問題設(shè)計開發(fā)了傳動軸式自行車。該自行車采用傳動軸代替鏈條的方式，前部用一對錐齒輪改變方向中間采用傳動軸后部采用一對錐齒輪改變方向再通過棘輪機構(gòu)與后輪相連接實現(xiàn)傳動，該自行車傳動部分改為傳動軸，其他部分與普通自行車相似。關(guān)鍵詞：自行車；傳動軸；錐齒輪；設(shè)計中圖分類號： 文獻標(biāo)識碼：A 文章編號：引言在科技日益發(fā)達的當(dāng)今社會，新型技術(shù)不斷被研發(fā)并輻射到社會的實際運用中去，隨著人們環(huán)境意識的不斷增強，人們都在尋著能夠省時省力節(jié)能的新型代步工具！都在為共創(chuàng)和諧的節(jié)約型社會而努力！隨著居民生活水平的不斷提高，自行車的使用不僅僅再是普通的代步工具，而逐漸成為人們娛樂、休閑、鍛煉的首選工具。行駛途中，可以當(dāng)做普通自行車騎行鍛煉身體，隨著時間的推移，原始簡單的鏈傳動自行車已不再滿足人們的心里，人們都希望完善自行車的傳動方式功用，以給人們帶來更多的方便。從早期的自行車雛型出現(xiàn)，到今天種類繁多、形式多樣的自行車產(chǎn)品，已經(jīng)歷了近200年的歷史，隨著社會的發(fā)展、技術(shù)的進步、產(chǎn)品的更新、生活節(jié)奏的加快, 人們在享受物質(zhì)生活的同時, 更加注重產(chǎn)品的方便、舒適、可靠、價值、安全、效率等人機性能, 創(chuàng)新設(shè)計即充分發(fā)揮人的創(chuàng)造才能,利用技術(shù)原理進行創(chuàng)新構(gòu)思的設(shè)計實踐活動，其目的是為人類社會提供富有新穎性和先進性的產(chǎn)品.因此，創(chuàng)新設(shè)計的基本特征是新穎性和先進性?！靶路f性”就是設(shè)計者不拘于前人或別人已有的成就,敢于根據(jù)從未嘗試過的想法去進行新的探索,設(shè)計出別具一格的產(chǎn)品。“先進性”就是設(shè)計的產(chǎn)品不僅應(yīng)標(biāo)新立異，而且在技術(shù)水平上比現(xiàn)有的類似產(chǎn)品要超前一步，即在功能、性能、結(jié)構(gòu)等方面顯示出新的特點和實質(zhì)性的改進，創(chuàng)新設(shè)計即充分發(fā)揮人的創(chuàng)造才能，任何一種設(shè)計都離不開創(chuàng)新，工業(yè)設(shè)計領(lǐng)域中,無論是對傳統(tǒng)產(chǎn)品的改進性設(shè)計,還是對新產(chǎn)品的開發(fā)性設(shè)計都需要創(chuàng)新。因此,對自行車進行創(chuàng)新設(shè)計和概念設(shè)計具有重要意義，對傳動軸自行車設(shè)計通過對鏈輪改造，把前鏈輪改造成一對錐齒輪傳動 中間通過傳動軸代替鏈條，后輪在通過一對錐齒輪改變傳動的方向設(shè)計要求1 設(shè)計原理及機構(gòu)1.1 設(shè)計原理針對自行車的掉鏈和傳動效率低問題研制了傳動軸式自行車，該自行車前部采用一對錐齒輪中間采用傳動軸后部采用一對錐齒輪，從而就改變了現(xiàn)有自行車的缺點，掉鏈和傳動效率低和有鏈傳動帶來的噪音等問題。傳動部分如圖1所示。1 錐齒輪 2錐齒輪 3傳動軸 4錐齒輪 5錐齒輪圖1 傳動的主要零部件其優(yōu)點是不會產(chǎn)生掉鏈，效率較高，不會對出現(xiàn)對褲子出現(xiàn)的撕咬，填補了國內(nèi)沒有該形式的自行車的空白，使對自行車感覺會更加舒適和平穩(wěn)，提高了各部分的通用性能，1.2 總體設(shè)計傳動軸式自行車的整體布局如圖21車胎 2輻條 3后軸 4后部錐齒輪殼體 5軸承端蓋 6傳動軸 7車座 8車架 9與車架固定螺栓 10軸承端蓋螺栓 11前部錐齒輪殼體 12自行車車把圖2 傳動軸自行車總體布局圖 該自行車在人的腳動力下驅(qū)動，工作時人腳驅(qū)動腳蹬子帶動軸，有軸帶動前部一對錐齒輪轉(zhuǎn)動，在通過軸傳遞給傳動軸，再有傳動軸傳遞給尾部的一對錐齒輪使其轉(zhuǎn)動，然后在傳遞給棘輪機構(gòu)，有棘輪機構(gòu)傳遞給自行車后輪，使自行車能夠在大地上行駛，該自行車傳動部分追要有三大部分，前部錐齒輪系統(tǒng)，中間傳動軸系統(tǒng)，和尾部錐齒輪系統(tǒng)，前部錐齒輪系統(tǒng)主要作用是，改變傳動的方向和增速，中間傳動軸主要是能夠較遠距離的傳遞動力，傳動軸花鍵的作用是能夠由于十字軸轉(zhuǎn)動使傳動軸的軸向的位移得到平衡，尾部錐齒輪的作用改變方向進一步的使系統(tǒng)增速，其主要技術(shù)參數(shù)如下:外形尺寸/mm：17351040520作業(yè)速度/km/h ：1015驅(qū)動力轉(zhuǎn)速r/min : 602 關(guān)鍵部件設(shè)計2.1 傳動軸 錐齒輪傳動軸采用45剛制造，中間采用空心式的，外徑為12mm內(nèi)徑為6mm，傳動軸分為兩段前段部分和后段部分，中間用矩形花鍵連接傳動軸的設(shè)計公式如下式中 d-計算截面處軸的直徑 -與材料有關(guān)的常數(shù) P-軸傳遞的功率 -常數(shù)通常取0.5-0.6 n 軸的轉(zhuǎn)速每對錐齒輪的小齒輪的材料使用40Cr，大齒輪使用45鋼，按吃面接觸疲勞強度設(shè)計-彈性影響系數(shù)-需用應(yīng)力K-動載系數(shù)-轉(zhuǎn)矩-齒寬系數(shù)-傳動比2.2 其它部件 對原有的棘輪機構(gòu)進行改造如圖3圖3改造后的棘輪改造后的棘輪使其能夠與最后一級齒輪結(jié)合使其能夠?qū)崿F(xiàn)傳動，對車架的改造如圖4圖4 對自行車架的改造1處的改造使其能夠與齒輪箱相連接并將齒輪箱固定住，2處的改造是為了不讓傳動軸與傳動軸干擾。3結(jié)論1）該自行車能夠有效的避免普通鏈傳動自行車所帶來的掉鏈，傳動效率低，由于騎車不當(dāng)帶來了的撕咬衣服等問題。該自行車完全滿足自行車的行駛要求。2）該自行車首次提出了以傳動軸傳動代替普通自行車的鏈條傳動。提高了傳動效率傳動效率在91%左右，使人騎起來感覺會更加的省力。3）若這種新的傳動方式能夠勾起那些近距離開車的人放棄開車，改為以這種自行車代步，那我們便會減少汽車的尾氣排放更好的保護我們的環(huán)境。參考文獻1孟憲源,姜琪.機構(gòu)構(gòu)型與應(yīng)用M.機械 工業(yè)出版社,1966.2吳宗澤,羅圣國.機械設(shè)計課程設(shè)計手冊 M.高等教育出版社,1965.3成大先,機械設(shè)計手冊機械傳動M .化學(xué)工業(yè)出版社，1982.4孫桓, 陳作模, 葛文杰.機械原理 M.第七版.高等教育出版社，1967.5傳動軸萬向節(jié)安裝M. 實用汽車技術(shù)，2006/036 陳敏 , 劉曉敘.AUTOCAD教程M.機械工 業(yè)出版社，1988.7江耕華，胡來瑢，陳啟松 .機械傳動設(shè)計 手冊（上冊M）.北京：煤炭工業(yè) 出版 社,1982.8成大先 ,機械設(shè)計手冊（單行本） .軸承 M, 化學(xué)工業(yè)出版社，1982.9成大先,機械設(shè)計手冊（單行本）M. 機 械制圖極限與配合,化學(xué)工業(yè)出版社，20 1110龔淅義 ,羅圣國 李平林 張立乃 黃少 顏編機械設(shè)計課程設(shè)計指導(dǎo)書（第二 版 ）M .高等教育出版社，1992.11濮良貴 紀(jì)名剛主編. 機械設(shè)計（第七 版）M.西北工業(yè)大學(xué)機械原理及機械 零件教研室,高等教育出版社，2006.12成大先, 機械設(shè)計手冊（單行本） 軸及 其聯(lián)接M, 化學(xué)工業(yè)出版社,1982.13吳宗澤 羅圣國, 機械設(shè)計課程設(shè)計手 冊M ,機械工業(yè)出版社,1965.14吳宗澤,機械結(jié)構(gòu)設(shè)計M，北京機械工 業(yè)出版社,1989.15 羊拯民主編.傳動軸和萬向節(jié)M.北京：人民交通出版社，19864788Drive Axle Type Bicycle DesignHao Liangqing（College of Mechanical and Electrical Engineering，Tarim University，Alar 843300，China）Abstract: China is a big country in view of the traditional bicycle, chain transmission bicycle problems, easy to swap chain, transmission efficiency, etc. Design and development of a transmission shaft type bicycle. The bike the drive shaft instead of the chain mode, front with a pair of bevel gear change direction is used in the middle drive shaft rear uses a pair of bevel gears change the direction through the ratchet mechanism and the rear wheel are connected to realize transmission, the bicycle transmission part to drive shaft, and the other parts are similar to ordinary bicycle.Key words: Bicycle; drive shaft; bevel gear; designOptimizing a Hydraulic Regenerative Braking System for a 20 Bicycle Wheel Executive SummaryWith a growing concern of climate change and decreasing availability of fossil fuels, the U.S. Environmental Protection Agency (EPA) has been researching hydraulic hybrid transportation systems. For seven years, the EPA and ME450 students at The University of Michigan (U-M) have collaborated on projects developing Hydraulic Regenerative Braking Systems (HRBS) for bicycles. These systems conserve energy that is normally lost during friction braking. The bikes kinetic energy is used to drive hydraulic fluid into an accumulator via a pump, braking the vehicle. This stored energy is later released to accelerate the bike forward. This semester we have refined previous HRBS designs by optimizing the mechanical systems and improving safety. A key goal for our team was to build a functioning prototype 20 wheel that weighs less and has fewer moving parts than previous generations. Our team has made minimal changes to the extant hydraulic system, as the parts have been well-researched and recommended by our sponsor, David Swain of the EPA. Working with Mr. Swain, we created a list of customer requirements for this project. Table 1 below lists many of our key engineering specifications that were created to meet these requirements, as well as the final characteristics of the prototype. Our four categories for engineering specifications are safety, cost, weight, and functionality. Due to the conflicting nature of these specifications, it has been difficult to improve many of the bikes systems without adversely affecting others. Compromises have been necessary in order to create a feasible design.table 1：summary of key engineering specificationsCharacteristic Target prototypeFront wheel assembly weight 30lbs 24.75lbsBicycle load rating(rider weight) 160lbs 200lbsSystem pressure as limited by relief vale 4200psi 4200psiBicycle deceleration target 3.4m/s2.6m/s not availableBicycle acceleration target 2.0m/s2.5m/s not availableNumber of moving/ rotating parts inside hub 11 7Prototype cost $1400 $1338 Many of the main hydraulic components have long acquisition lead times. To meet our goal of having a functional prototype by the end of the term, we expedited concept generation and selection so as to leave enough time to order and receive these parts. We created a detailed plan for the semester based on expected task requirements as well as these lead times.In reducing the weight of the prototype compared to previous designs, we have significantly reduced the number of gears, replaced the bulky fiberglass hub support system with a lightweight aluminum spoke system, and removed excess material from the internal support plate (superbracket). These modification choices were made from a broad number of concepts, based on a thorough analysis of the forces and torques required of each of the components. The main engineering obstacles to implementing these design improvements have been dealing with the nonstandard interface between metric and non-metric components, and determining the routing of the hydraulic circuit. 1 AbstractThe U.S. Environmental Protection Agency (EPA) is researching hydraulic hybrid transportation systems in an effort to address the growing concerns about global climate change and insatiable fossil fuel demands. Hydraulic hybrid vehicles use regenerative braking to store energy in pressurized fluids. This energy is then released to assist in vehicle acceleration. For the past seven years, ME450 students at The University of Michigan (U-M) have been developing designs for hydraulic hybrid bicycle systems. This semester we refined the design of a hydraulic hybrid system enclosed in a 20 bicycle wheel, with a focus on decreasing weight, improving safety, and reducing the number of moving parts.2 IntroductionThis section outlines the origins of the hydraulic hybrid bicycle system concept at the EPA as well as the driving force for its development. A brief outline of the projects scope for the Winter 2009 semester of ME450 is also presented below.2.1 Background and MotivationFounded in 1970, the United States Environmental Protection Agency is a federal body tasked with correcting environmental damage and establishing guidelines to help protect the natural environment of the United States 1. Research into clean energy, particularly for use in transportation, is the focus of several of the EPAs efforts 2. In cooperation with Eaton Corporation, United Parcel Service, Ford, International, and the U.S. Army, the EPA has developed several hydraulic hybrid vehicles for the purposes of improving fuel economy and reducing environmental impact 3.The primary concept of hydraulic hybrid technology is to capture and utilize the energy that would otherwise be lost during braking and use it to accelerate the vehicle. As the vehicle brakes, a hydraulic pump connected to the drivetrain pumps hydraulic oil into the high-pressure accumulators. During vehicle acceleration, the energy stored in the accumulators is released back into the drivetrain, as the fluid flows through a hydraulic motor. This significantly lowers the amount of fuel needed to accelerate back to normal operating speeds 3. The result of this regenerative braking is a marked improvement in fuel economy - a feature that is not just better for the environment, but also reduces fuel costs for the owner. A diagram showing this hydraulic regenerative braking system (HRBS) is shown in Figure 1 on page 6. Figure 1: The hydraulic fluids path in an HRBS 4 The use of bicycles for commuting reduces fossil fuel use, greenhouse gas emissions, roadway congestion, and vehicle miles traveled while increasing the users physical health 5. The EPA has demonstrated 20-40 percent fuel economy improvements by installing HRBS on vehicles with internal combustion engines 3. The possibility of clean, efficient transportation with hydraulic assistance bears exploration. The EPA has been working with U-M students on hydraulic bicycle implementation since 2002, but the project has produced only one functional product.2.2 Project DescriptionThe goal of this project is to develop a hydraulic regenerative braking system for a childrens 20 bicycle. Due to the difficult nature of scaling down a hydraulic system, and the comparative ease of scaling upwards, the intent of using a 20 bicycle is to analyze the weight, force, and torque issues inherent to the HRBS on a small scale.The EPA has been working on HRBS bicycles with ME450 students for the past seven years. Previous ME450 teams have worked on fitting these systems in 26 and 20 bicycle wheels. The primary focus of our work on the HRBS is refining the existing designs by improving safety, reducing weight, ensuring functionality, and lowering cost. We are designing an HRBS for a 20 wheel. Notably, one of the main goals is to reduce the device weight to 30 lbs without sacrificing mechanical robustness or safe pressure containment. We plan to retain the majority of the hydraulic components from past designs, as this technology has been well-researched and documented by David Swain and previous teams. By focusing on reducing moving parts, decreasing weight, and improving safety, we are further developing the understanding and implementation of HRBS technology through the fabrication of a functional prototype.3 Information SearchTo gain a better understanding of hydraulic hybrid systems, our team surveyed a broad collection of information including research papers, previous ME450 reports, and EPA resources. This section of the report discusses the information we found regarding hydraulic hybrid vehicle technology.Hydraulic systems are used in a variety of applications such as machinery, braking systems, and energy storage. They are often used because of their ability to transfer large forces and convert kinetic energy into potential energy efficiently. To safely utilize this technology, many precautions must be taken to prevent high-pressure systems from rupturing.The EPA, U-M, and companies such as Eaton and Ford have been developing hydraulic hybrid systems for transportation applications including cars, trucks, and bicycles. Hydraulic hybrid bicycle technology has been pioneered through a partnership between the EPA and U-M. For seven years, ME450 students at U-M have been researching, designing, and building hydraulic hybrid bicycle systems using HRBS. These systems require improvements in safety, functionality, and performance.4 Project Requirements & Engineering SpecificationsTo outline the specifications for this project, we began by defining our customer requirements. We then translated these requirements into engineering specifications. This section of the report details these requirements and the resulting specifications.4.1 Customer RequirementsThe customer requirements for this term, as outlined by our sponsor David Swain, are continuations of the past two semesters with an added emphasis on three major underlying themes-safety, performance, and cost- to guide the formation of our engineering specifications. Table 1 on page 11 shows a listing of our customers requirements, as grouped by the three major themes and their relative importance in each.4.2 Engineering SpecificationsWhen translating the customer requirements into engineering specifications, cost and safety translated directly. However, performance split into weight and functionality, as we find both categories of high enough importance to be separate. The resultant engineering specifications are described in the following list. 5 Concept Generation To effectively generate a broad collection of concepts, we began by decomposing the main subsystems of the HRBS. After breaking down the subsystems, we listed the main components of each. Each team member then created a list of concepts for each of the components. We then met as a team to build on one anothers ideas and we created a master concept list 5.1 Functional Decomposition Based on the unique history and relative complexity of our project, we followed a slightly different concept generation process than most teams. We began by decomposing the bicycle HRBS into five functional subsystems. These subsystems are hydraulics, powertrain, hub, superbracket, and user interface. Each of these subsystems contained at a minimum two major components. Figure 3 is a functional decomposition tree showing which components fall under which subsystem.Figure 3: Functional decomposition tree outlining main components of each subsystem After completing the functional decomposition, we generated concepts for each of the subsystem components. By individually creating concepts and analyzing them as a team, we were able to attack each design problem from multiple angles. 5.2 Hydraulics The subsystem most refined by previous teams is hydraulics. This is also the subsystem with the longest lead-time items. As a result, many of our hydraulic 5.2 Hydraulics The subsystem most refined by previous teams is hydraulics. This is also the subsystem with the longest lead-time items. As a result, many of our hydraulic components including the pump, motor, high pressure accumulator, tubing & fittings, and low pressure reservoir till remain the same as those specified by previous teams.In addition to the systems used on previous generations, it is important to include a pressure relief system to prevent over-pressurizing the system. This can be achieved by including a variable pressure relief valve or a burst disc. The valves category is made up of a check valve preventing high pressure flow from entering the pump and a directional valve to start and stop the launch process. There are various types of check valves that respond better to different pressures. The directional valve could either be a two-way or a three-way electronic valve. There are different types of each of these valves that vary in their sealing method. Poppet valves seal quite well, leaking only a few drops per minute; spool valves can leak multiple milliliters per minute.5.3 Powertrain & PackagingPowertrain decomposes into only two component categories, but it is very complicated due to the packaging constraints of a 20 bicycle wheel. In the past, the mechanical reduction was created using steel spur gears. We generated many concepts including plastic gears, phenolic gears, sprockets & chain, cogged belts, cables & pulleys, and friction rollers like those used to launch roller coasters. The second powertrain category is clutch mechanisms. A system is needed to disengage the pump and motor from the rotating hub when braking and launching are not engaged. Concepts to complete this task included electromechanical clutches (benchmark), mechanical clutches, roller clutches, and a custom clutch utilizing a linear actuator. 5.4 Hub The hubs main roles on the bike are to support the rim, to interface with the mechanical reduction, and to enclose the systems moving components. This hub rotates around the bikes axle, which is stationary. Previous teams have created hubs made of carbon fiber and fiberglass. We included these in our concept list as well as aluminum sheet metal, vacuum formed plastic, and spokes with a thin cover. We developed another concept by combining the spoke and vacuum form designs. In this design a rigid skeletal structure would be used to support the bicycle and a thin plastic cover would enclose the system. 5.5 SuperbracketThe superbracket subsystem is made up of the superbracket and the bikes axle. These components are rigidly connected together. The hub rotates on the axle and electric wiring exits the hub through the center of the axle. Designing the superbracket is a material selection and thickness optimization problem. The bracket needs to support the hydraulic and mechanical components and prevent the pump and motors output/input shafts from being loaded radially. To meet these criteria we created a list of potential materials, including steel, aluminum, fiberglass, tooling board, wood, carbon fiber, and plastic. Along with material selection we have discussed methods of increasing the brackets stiffness by using dimple dies, adding gussets, and adding angle iron reinforcements. 5.6 User Interface and Controls Previous designs incorporated a switch box for controlling the brake and launch functions. This box was mounted on the frame of the bike directly in front of the seat. While functional, this forces the rider to let go of the handlebars with at least one hand to activate either system. In the event of a system braking failure, the rider would have to quickly adjust his hand position to activate the hand brake on the handlebar. One concept that could potentially solve this problem is to integrate the switch and the preexisting hand brake. This could be done by splicing a toggle switch into the cable. A light squeeze on the hand brake could activate the HRBS, while a hard squeeze would be enough to engage the friction brakes. Another option, provided that the bike is equipped with front and rear brakes, is to leave the rear hand brake unmodified and splice a toggle switch into the front hand brake cable. The launch activation could potentially be switched via a toggle switch mounted on the handlebars, or a pushbutton mounted on the handlebars. If two switches are wired in parallel, there is the advantage that both switches must be activated for the launch to be triggered - this could be beneficial from a safety standpoint.6 ConclusionThis semester we designed and built a hydraulic regenerative braking system enclosed in a 20 bicycle wheel. We used hydraulic hybrid technology that was proven by the EPA and previous ME450 teams. Using the vast resources available to our team, we redesigned the mechanical and electrical systems on the bike. The hydraulic component specifications did not change from previous iterations of the bicycle. We reduced weight, improved safety, and increased functionality with our design and were motivated by those driving factors during manufacturing and assembly. We were able to meet the deadlines of our project by sourcing parts aggressively and scheduling proactively throughout the semester. In such a short design cycle, adherence to a methodical and thoughtful approach was necessary to avoid confusion and misguided efforts. It also allowed for each team member to have an intimate knowledge of the system and its components, resulting directly in a significant leap forward in the evolution of this project.20英寸自行車輪液壓濕式制動系統(tǒng)的優(yōu)化設(shè)計 摘要 隨著氣候變化和減少使用化石燃料日益受到關(guān)注，美國環(huán)境保護署（EPA）已研發(fā)了液壓混合動力運輸系統(tǒng)。在7年時間中，EPA和美國密西根大學(xué)（UM）的學(xué)生組成的機械工程450團隊（ME450）為發(fā)展自行車液壓再生制動系統(tǒng)（HRBS）進行了項目合作。一般來說，這些系統(tǒng)節(jié)約了在摩擦制動過程中丟失的能源。它采用了將自行車的動能通過泵液壓油的流動進入蓄能器，從而制動車輛。而此次儲存的能量將釋放來加速自行車向前行駛。這學(xué)期，我們通過優(yōu)化機械系統(tǒng)和改善其安全來改進以前HRBS設(shè)計。我們團隊的主要目標(biāo)是建立一個正常運作的原型20輪，它重量更輕，并具有運動部件少。比前幾代，作為它部分的設(shè)計已精心研究，我們的團隊取得了現(xiàn)存的液壓系統(tǒng)的微小變化。此次設(shè)計由我們的贊助商，大衛(wèi)環(huán)保局史懷恩先生指導(dǎo)，我們建立了一個滿足客戶的要求項目清單。下面的表1列出了許多我們的重點工程，并創(chuàng)造了滿足這些要求的規(guī)格，以及最后的樣機特征。我們的四大類工程規(guī)格為，安全性、成本、重量和功能性。由于這些規(guī)格與其性質(zhì)的沖突，它一直難以改善自行車的許多系統(tǒng)而對他人設(shè)計產(chǎn)生不利影響。妥協(xié)以創(chuàng)造一個可行的設(shè)計是必要的途徑。表1：重點工程規(guī)格概要特征 指標(biāo) 樣機前輪的裝配重量 30磅 24.75磅自行車額定負(fù)載（騎手體重） 160磅 200磅限量系統(tǒng)壓力安全閥 4200psi 4200psi自行車減速指標(biāo) 3.4m/s2.6m/s 無法取得 自行車加速指標(biāo) 2.0m/s2.5m/s 無法取得移動/旋轉(zhuǎn)樞紐內(nèi)部零部件數(shù)量 11 7 樣機成本 1400美元 1338美元許多主要的液壓元件需要長期收購多次。為了完成我們?nèi)纹诮Y(jié)束時作出一個擁有這些功能的樣機的目標(biāo)，我們加快觀念的生成和選擇，從而以留出足夠的時間訂購和接收這些部件?；陬A(yù)期的任務(wù)要求以及交貨時間，這學(xué)期我們創(chuàng)造了一個詳細(xì)的計劃。與以前的設(shè)計相比，我們已經(jīng)大大降低了齒輪的數(shù)量來減輕樣機的重量，用一個輕型鋁合金發(fā)言系統(tǒng)來取代笨重的玻璃纖維樞紐的支撐系統(tǒng)，并從內(nèi)部支撐板（“superbracket”）去除多余的材料。這些修改的選擇來自于一個基于深入分析每個組件所需的力量和扭矩廣泛的概念。實現(xiàn)這些涉及公制和非公制元件之間的非標(biāo)準(zhǔn)接口這項主要工程的障礙進行改進設(shè)計，并確定液壓回路的路線選擇。1摘要美國環(huán)境保護署（EPA）正在努力研究液壓混合動力運輸系統(tǒng)以解決有關(guān)全球氣候變化和貪得無厭的化石燃料的需求得到越來越多的關(guān)注。在過去的7年里，ME450在美國密西根大學(xué)（UM）的學(xué)生為液壓混合動力自行車系統(tǒng)設(shè)計作出發(fā)展，液壓混合動力汽車使用再生制動儲存能量加壓液體這種能量的釋放可以協(xié)助車輛加速。這學(xué)期，我們提出20英寸自行車輪內(nèi)的液壓混合動力系統(tǒng)的設(shè)計，重點是降低重量，提高安全性，并減少移動部件的數(shù)量。 2引言本節(jié)概述了液壓混合動力系統(tǒng)的概念、自行車環(huán)保局的起源以及其發(fā)展的原動力。此項目在2009年冬季學(xué)期ME450范圍內(nèi)進行，概要介紹如下。2.1背景和動機 美國環(huán)境保護局成立于1970年，是一個負(fù)責(zé)糾正損害環(huán)境和建立指引的聯(lián)邦機構(gòu)，以幫助保護美國的自然環(huán)境1。主要研究清潔能源，特別是運輸是EPA的努力的幾個重點2。與伊頓公司、聯(lián)合包裹運送服務(wù)公司、福特、國際和美國軍隊保持合作，環(huán)保局已開發(fā)出幾種改善燃油經(jīng)濟性和減少對環(huán)境的影響為目的的液壓混合動力汽車3。液壓混合動力車技術(shù)的主要概念是捕捉和利用，否則將失去制動過程中用它來加快車輛的能源。作為汽車制動器，液壓泵連接到傳動泵的液壓油進入高壓蓄能器。在車輛加速過程中，在蓄能器儲存的能量被釋放到動力傳動系統(tǒng)，液體流動通過液壓馬達。這大大降低了所需的燃料，回到正常的運行速度以加速3。這種再生制動的結(jié)果是在燃油經(jīng)濟性上明顯的改善不僅是對環(huán)境有益，也為業(yè)主降低燃料成本的特點。這種液壓再生制動系統(tǒng)（HRBS）（如圖1所示）的圖表在第6頁上顯示。 圖1：液壓油在HRBS上的路徑4使用自行車作為交通工具上下班，減少了化石燃料的使用、減輕了溫室氣體排放、減緩了道路擁堵，同時騎行自行車數(shù)英里還提高了用戶的身體健康5。環(huán)保局已經(jīng)證明在內(nèi)燃發(fā)動機的車輛上安裝HRBS可改善20-40的燃油經(jīng)濟值3。自2002年以來，環(huán)保局已與澳學(xué)生對液壓自行車實施狀況進行合作，對其具有清潔、液壓助力式承擔(dān)的高效的運輸可能性進行探索。但該項目產(chǎn)生只有一個功能性的產(chǎn)品。 2.2工程項目說明這個項目是以開發(fā)20英寸兒童式自行車液壓再生制動系統(tǒng)為目標(biāo)。由于液壓系統(tǒng)在同比例大小進行縮放向下的艱巨性和縮放向上較為容易性，因此選擇20英寸這個尺寸研究HRBS自行車，它在分析重量、力的大小、和固有的扭矩問題上較為合適。在過去的7年,環(huán)保局和機械工程學(xué)450的學(xué)生一直致力于研究HRBS自行車。以前的ME450隊一直在26英寸和20英寸自行車輪子上擬合這些系統(tǒng)。我們在研究HRBS方面的主要焦點是改善現(xiàn)有的設(shè)計，以提高它的安全性、降低重量、確保功能性和降低成本。值得注意的是，我們正在設(shè)計的20英寸輪HRBS系統(tǒng)，其主要目標(biāo)之一是在不犧牲機械強度或壓力容器的安全的前提下將設(shè)備的重量減少到30磅。我們的計劃是保留大部分過去設(shè)計的液壓元件，因為這項技術(shù)已由大衛(wèi)_斯溫和以前的團隊得到了很好的研究和記錄。我們正在進一步制定一個HRBS技術(shù)的、以減少運動部件、降低重量、提高安全性為重點的功能樣機。3信息收集為了更好的理解液壓混合動力系統(tǒng)，我們團隊調(diào)查了廣泛收集的信息，其中包括研究論文、以前ME450的報告和環(huán)保局的資源。在這部分報告所顯示的信息中我們找出了液驅(qū)混合動力車輛技術(shù)。液壓系統(tǒng)在如機械、制動系統(tǒng)、儲能等各種應(yīng)用場合下受到使用。由于液壓系統(tǒng)傳輸較大的力的性質(zhì)和高效地將勢能轉(zhuǎn)換成動力的能力而受到了大家廣泛地使用。為了安全地利用這項技術(shù)，我們必須采取預(yù)防措施，以防止因高壓而爆裂液壓系統(tǒng)。4項目要求及工程規(guī)范該部分概述了這個項目的規(guī)格，我們首先了解我們的客戶的需求。然后我們改變工程規(guī)格要求來滿