課程設(shè)計二級圓柱齒輪主減速器設(shè)計

1、 機(jī)械設(shè)計課程設(shè)計說明書 設(shè)計題目：二級圓柱齒輪減速器學(xué) 校：專 業(yè)：汽車工程系班 級：車輛09學(xué) 號： 設(shè) 計 人：指導(dǎo)老師：完成日期：2011 年 1月20日目 錄一、 機(jī)械設(shè)計課程設(shè)計題目.3二、 電動機(jī)的選擇.4三、 V帶的選擇. 6四、 齒輪的設(shè)計計算.8五、 軸的設(shè)計計算13六、 滾動軸承的選擇及計算18七、 聯(lián)軸器的選擇計算21八、 鑄件減速器機(jī)體結(jié)構(gòu)尺寸計算表及附件的選擇21九、 潤滑與密封方式的選擇、潤滑劑的選擇23十、 小結(jié) 23一、機(jī)械設(shè)計課程設(shè)計題目題目名稱：設(shè)計兩級圓柱齒輪減速器說 明：此減速器用于處理車間零件清洗傳送帶動減速。此設(shè)備兩班制工作，工作期限八年，戶內(nèi)使用

2、。傳送簡圖如下：原始數(shù)據(jù)：題號參數(shù)4鼓輪直徑（mm）420傳送帶運(yùn)行速度（m/s）0.8傳送帶的拉力（N）5350二. 設(shè)計要求1.減速器裝配圖一張(A1)。2.零件工作圖2張(A3)。3.設(shè)計說明書一份。三. 設(shè)計步驟1. 傳動裝置總體設(shè)計方案2. 電動機(jī)的選擇3. 確定傳動裝置的總傳動比和分配傳動比4. 計算傳動裝置的運(yùn)動和動力參數(shù)5. 設(shè)計V帶和帶輪6. 齒輪的設(shè)計7. 滾動軸承和傳動軸的設(shè)計8. 鍵聯(lián)接設(shè)計9. 箱體結(jié)構(gòu)設(shè)計10. 潤滑密封設(shè)計11. 聯(lián)軸器設(shè)計12.選擇潤滑方式、潤滑劑牌號及密封件四、電動機(jī)的選擇1、電動機(jī)型號的確定各類數(shù)據(jù)：F=5350N D=420mm 帶速V=0

3、.8m/s卷筒軸轉(zhuǎn)速；n = 36.38r/min 工作機(jī)所需功率： =FU/1000=5350*0.8/1000 =4.28Kw總效率： 0.99×× ×0.96×0.950.8(式中，為從電動機(jī)至卷筒軸之間的各傳動機(jī)構(gòu)和軸承的效率。由參考書中表查得： 彈性聯(lián)軸器；滾子軸承；圓柱齒輪傳動；滾筒效率=0.96V帶傳動電動機(jī)輸出功率：=4.28/0.8=5.35Kw由課程設(shè)計書中查得電動機(jī)額定功率 P= 5.5Kw電動機(jī)型號額定功率kw滿載轉(zhuǎn)速r/min總傳動比減速器傳動比Y132M2-65.596026.3769.420Y132S-45.5144039.

4、56414.13由表中的數(shù)據(jù)可知，兩種方案均可以。由于兩級圓柱齒輪減速器的傳動比要求在860范圍內(nèi)，相比下，選擇電動機(jī)型號為Y132S-4。電動機(jī)型號電動機(jī)滿載轉(zhuǎn)速（r/min）外伸軸直徑D軸外伸長度E電動機(jī)中心高HY132S-4144038801322、 總傳動比、各級傳動比1）總傳動比由選定的電動機(jī)滿載轉(zhuǎn)速n和工作機(jī)主動軸轉(zhuǎn)速n，可得傳動裝置總傳動比為/n1440/36.39739.5642）各級傳動比 取V帶傳動比，取; 由此可算得，3、 各軸轉(zhuǎn)速 1440/2.81514.46r/min   514.46/3.75136.66r/min   &#

5、160;/ 136.66/3.75=36.44 r/min4、 各軸輸入功率 P= =5.5 kw×5.5×0.955.23kw   ×2×5.28×0.97×0.994.97kw  ×2×4.825×0.97×0.994.72kw =××=4.72×0.99×0.98=4.585、 各軸轉(zhuǎn)矩電動機(jī)軸的輸出轉(zhuǎn)矩=9550 =9550×5.5/1440=97.46 N·m9550 =9550

6、5;5.025/514.286=347.31 N·m9550=9550×4.825/136.815=1236.99 N·m9550=9550×4.634/36.397=1200.30N·mn=44.8r/minP=4.2W =0.82P= 5.5Kw=39.58=512.46 r/min=136.66r/min=36.44 r/minP=5.5 kw5.23kwkw=4.72kw=4.58kw=97.46 N·m=347.31N·m=1200.30N·m匯總項(xiàng)目轉(zhuǎn)速r/min1440512.461366.6636.

7、44功 率kw74.72轉(zhuǎn) 矩Nm97.46347.311236.991200.30傳動比2.813.75375三、V帶的選擇（所用公式、各類查表數(shù)據(jù)來自機(jī)械設(shè)計 基礎(chǔ)） 1）、計算功率 查表得KA=1.2 =2)、選擇V帶型 根據(jù)=6.6Kw、=1440r/min由機(jī)械設(shè)計教程書圖5.8查得此坐標(biāo)點(diǎn)位于A區(qū)域，故選擇A型帶。3）、求大，小帶輪基準(zhǔn)直徑d2,d1并驗(yàn)算帶速V(1)、由表5.4，d1應(yīng)不小于75mm，現(xiàn)取d1=112mm =2.7 ×112=302.4 mm 取d2=315mm（2）、驗(yàn)算帶速v 8.44m/s在5m/s-25m/s的范圍內(nèi)，符合。（

8、3）、確定V帶的中心距a和基準(zhǔn)長度 0.7 初選中心距： =500mm 取計算實(shí)際中心距=+( -)/2640.5mm（4）.驗(yàn)算小帶輪包角 180°-×180°-×60° 159°>120° 包角合適（5）.求V帶根數(shù)單根V帶所能傳達(dá)的功率 由=1440r/min 和=112mm 實(shí)際傳動比i=2.81查表5.7a得=1.60kw 查表5.7b得=0.17kw查表5.8得包角修正系數(shù)=0.946查表13-2得帶長修正系數(shù)=1.01Z= =3.39 故取4根.（6）計算帶傳動的壓軸力 查表5.1得q=0.1kg/m =

9、 =166.61N=2Zsin=1310.56N（7）. 帶的設(shè)計 小帶輪：小帶輪為實(shí)心式，中心 孔的直徑d=42mm為電動機(jī)的軸徑，輪轂長度l=50. 大帶輪：大帶輪為腹板式，中心孔d=55mm,輪轂長度l=60mm四、齒輪傳動設(shè)計計算 （采用斜齒）第一組齒輪減速器高速級齒輪傳動比為，高速軸轉(zhuǎn)速，傳動功率為1、選定齒輪類型、精度等級、材料及齒數(shù)1）大小齒輪都選用硬齒面。由表7.1選大小齒輪的材料均為45鋼，表面淬火，齒面硬度4050HRC2)選八級精度等級3）選小齒輪=25。選大齒輪齒數(shù)取=944）粗選螺旋角=15°2、按齒面接觸疲勞強(qiáng)度設(shè)計 1）取載荷系數(shù)K=1.52）齒寬系數(shù)3

10、）小齒輪傳遞的轉(zhuǎn)矩4）=9550 =9550×5.5/1440=97.46 N·m彈性影響系數(shù)5）節(jié)點(diǎn)區(qū)域系數(shù)由6）端面重合度 7）接觸疲勞強(qiáng)度極限:由表7.5查得Hlim =Hlim =1140MPa8）應(yīng)力循環(huán)N1=60n1JLh=60136.661（283658）=3.83109 N2= 9）接觸疲勞壽命系數(shù)，由圖7.3得 8） 接觸疲勞許用應(yīng)力H1 =×Hlim =1014.6MPaH2 =×Hlim=1037.4MPa(H1+H2 )/2=1026<1.23H1故取H =1026MPa3計算1）小齒輪分度圓直徑： 2）計算圓周速度 3）計

11、算齒寬b×38.096=34.262mm4）計算齒寬與齒高之比5）計算載荷系數(shù)K： 由圖7.5查得Kv=1.10，由表7.5查得K=1.40，由表7.4查得KA=1.00 ,KH參考表7.6中6級精度公式K=KAKvKHaKH6）按實(shí)際的載荷系數(shù)修正分度圓直徑 7）計算模數(shù) 4、按齒輪的彎曲強(qiáng)度設(shè)計計算 1) 確定公式中各參數(shù) 載荷系數(shù)K 2) 齒形系數(shù)YFa和應(yīng)力校正系數(shù)Ysa當(dāng)量齒數(shù) ， 用內(nèi)差法得YFa1=2.576，YFa2=1.599，Ysa1=2.204，Ysa2=1.7783) 螺旋角影響系數(shù)Y軸面重合度4）許用彎曲應(yīng)力F，查圖7.4得KFN1=0.86，K,FN2=0

12、.88查表7.3得,則5)確定取0,0111計算5計算模數(shù)比較兩種強(qiáng)度的計算結(jié)果。確定模數(shù)為mn=2.5mm幾何尺寸計算1） 中心距2） 修正螺旋角 4) 分度圓直徑 5) 齒寬b=取B2=60mm，B1=B2+5=65mm第二組齒輪減速器高速級齒輪傳動比為，高速軸轉(zhuǎn)速，傳動功率為1、選定齒輪類型、精度等級、材料及齒數(shù)1）大小齒輪都選用硬齒面。由表7.1選大小齒輪的材料均為45鋼，表面淬火，齒面硬度4050HRC2)選八級精度等級3）選小齒輪=25。選大齒輪齒數(shù)取=944）粗選螺旋角=15°2、按齒面接觸疲勞強(qiáng)度設(shè)計 1）取載荷系數(shù)K=1.52）齒寬系數(shù)0.73）小齒輪傳遞的轉(zhuǎn)矩=3

13、47.31N·m4）彈性影響系數(shù)5）節(jié)點(diǎn)區(qū)域系數(shù)由6）端面重合度 7）接觸疲勞強(qiáng)度極限:由表7.5查得Hlim =Hlim =1140MPa8）應(yīng)力循環(huán)N1=60n1JLh=60119.9921（283658）=3.83108 N2= 9）接觸疲勞壽命系數(shù)，由圖7.3得 8） 接觸疲勞許用應(yīng)力H1 =×Hlim =1014.6MPaH2 =×Hlim=1037.4MPa(H1+H2 )/2=1026<1.23H1故取H =1026MPa3計算1）小齒輪分度圓直徑： 2）計算圓周速度 3）計算齒寬b=43.04mm4）計算齒寬與齒高之比5）計算載荷系數(shù)K： 由

14、圖7.5查得Kv=0.50，由表7.5查得K=1.40，由表7.4查得KA=1.00 ,KH參考表7.6中6級精度公式K=KAKvKHaKH6）按實(shí)際的載荷系數(shù)修正分度圓直徑 7）計算模數(shù) 4、按齒輪的彎曲強(qiáng)度設(shè)計計算 6) 確定公式中各參數(shù) 載荷系數(shù)K 7) 齒形系數(shù)YFa和應(yīng)力校正系數(shù)Ysa當(dāng)量齒數(shù) ， 用內(nèi)差法得YFa1=2.576，YFa2=1.577，Ysa1=1.599，Ysa2=1.7788) 螺旋角影響系數(shù)Y軸面重合度4）許用彎曲應(yīng)力F，查圖7.4得KFN1=0.86，K,FN2=0.88查表7.3得,則5)確定取0,0111計算5計算模數(shù)比較兩種強(qiáng)度的計算結(jié)果。確定模數(shù)為mn

15、=2.5mm幾何尺寸計算1）中心距2）修正螺旋角 3）分度圓直徑 4）齒寬b=取B4=50mm，B3=B3+5=55mm6 齒輪的幾何參數(shù)齒頂高：齒根高：齒全高：齒頂圓直徑： 齒跟圓直徑：高速軸低速軸齒輪1齒輪2齒輪3齒輪4齒數(shù)z(mm)25942594齒頂圓直徑（mm）70.125294.8770.125294.87齒跟圓直徑（mm）58.878238.6258.87238.62齒寬（mm）65605550齒頂高（mm） 2.5中心距（mm）155155155155模數(shù)（mm）2.5螺旋角旋向左旋右旋右旋左旋分度圓直徑（mm）65.126244.8765.

16、126244.887五、軸的結(jié)構(gòu)設(shè)計計算（一）高速軸的機(jī)構(gòu)設(shè)計計算 由于高速軸上的齒輪直徑接近于軸徑，故將軸設(shè)計為齒輪軸。1、 高速軸的結(jié)構(gòu)如下圖所示：2）、中間軸的轉(zhuǎn)矩大齒輪2上的受力圓周力：徑向力：軸向力：小齒輪3的手里分析：圓周力：徑向力：軸向力：兩軸承支點(diǎn)的距離：齒輪3的對稱線與左軸承支點(diǎn)的距離：兩齒輪對稱線之間的距離：齒輪2的對稱線與左軸承支點(diǎn)間的距離：3） 計算中間反力（1） 水平面 （2） 垂直面（3） 水平面的彎矩 （4） 垂直面的彎矩： （5） 合成彎矩 單向運(yùn)轉(zhuǎn)，扭轉(zhuǎn)剪切應(yīng)力按脈動循環(huán)變應(yīng)力，取系數(shù)則：（6） 按彎矩合成應(yīng)力校核軸的強(qiáng)度 由計算彎矩知，C剖面的計算彎矩最大，

17、該處的計算應(yīng)力為： 安全。軸的受力如下圖所示：32、 軸II和軸III的結(jié)構(gòu)設(shè)計如下圖：軸II： 軸III:六、鍵的校核 高速軸安裝齒輪處的軸徑d=41,輪轂的寬度B=65 選普通平鍵，鍵長L=B-2-8=55，取L=56鍵的規(guī)格：b×h=12×8工作長度l=44校核鍵的工作強(qiáng)度鍵合格安裝帶輪處的軸徑d=25,輪轂的寬度B=60 選普通平鍵，鍵長L=B-2-8=50，取L=50鍵的規(guī)格：b×h=8×7工作長度l=42校核鍵的工作強(qiáng)度鍵合格中間軸安裝齒輪處的軸徑d=46,輪轂的寬度B=60 選普通平鍵，鍵長L=B-2-8=50，取L=50鍵的規(guī)格：b

18、15;h=14×9工作長度l=36校核鍵的工作強(qiáng)度 鍵合格安裝齒輪處的軸徑d=46,輪轂的寬度B=55 選普通平鍵，鍵長L=B-2-8=45，取L=45鍵的規(guī)格：b×h=14×9工作長度l=31校核鍵的工作強(qiáng)度低速軸安裝齒輪處的軸徑d=76,輪轂的寬度B=50 選普通平鍵，鍵長L=B-2-8=40，取L=40鍵的規(guī)格：b×h=14×9工作長度l=36校核鍵的工作強(qiáng)度不合格取鍵長L=70，工作長度l=48鍵合格裝聯(lián)軸器處的軸徑d=60,輪轂的寬度B=107 選B型鍵，鍵長L=B-2-8=97，取L=107鍵的規(guī)格：b×h=18×

19、;11工作長度l=79校核鍵的工作強(qiáng)度鍵合格七、滾動軸承的選擇及計算由條件知，減速器工作期限十年，兩班制工作，則軸承的預(yù)計壽命為（一）、對中間軸上滾動軸承的選擇及核計算1、中間軸滾動軸承的選用角接觸球軸承，如圖所示 2、對軸承進(jìn)行受力分析計算 1）徑向力軸向力計算當(dāng)量動載荷：由機(jī)械設(shè)計教程表10.8查得徑向載荷系數(shù)和軸向載荷系數(shù)：對于軸承1：對于軸承2：計算軸承的壽命： 兩年換檢修一次軸承。d2=315mmV=8.44m/s=640mm=1800mm159°V帶根數(shù)為4F0=192.62N=1899.78N七、聯(lián)軸器的選擇計算1、低速軸與工作機(jī)鼓輪軸用聯(lián)軸器連接，由于彈性柱銷聯(lián)軸器結(jié)

20、構(gòu)簡單，更換柱銷方便，緩和沖擊，吸收振動，故選用彈性柱銷聯(lián)軸器。2、求計算轉(zhuǎn)矩 軸III轉(zhuǎn)矩為 由機(jī)械設(shè)計教程表13-2查得工作機(jī)為輸送機(jī)時，工作情況系數(shù)，故計算轉(zhuǎn)矩為3、確定型號 由機(jī)械基礎(chǔ)設(shè)計課程設(shè)計 查得符合軸直徑為60mm的聯(lián)軸器選取型號為HL5彈性柱銷聯(lián)軸器，其公稱轉(zhuǎn)矩，軸材料為鋼時，許用轉(zhuǎn)速為4000r/min，允許的軸孔直徑在之間，故能滿足工作機(jī)與減速器聯(lián)接工作需要，從而確定聯(lián)軸器型號為HL4聯(lián)軸器 GB5014-85八、鑄件減速器機(jī)體結(jié)構(gòu)尺寸計算表及附件的選擇1、鑄件減速器機(jī)體結(jié)構(gòu)尺寸計算表名稱符號減速器及其形式關(guān)系機(jī)座壁厚0.025a+3mm=6.75mm,取10mm機(jī)蓋壁厚

21、10.02a+3=6 mm<8mm,取10mm機(jī)座凸緣厚度b1.5=12mm機(jī)蓋凸緣厚度b11.5=15mm機(jī)座底凸緣厚度p2.5=25mm地腳螺釘直徑df0.036a+12=17.4mm取20mm地腳螺釘數(shù)目na<250mm,n=4軸承旁連接螺栓直徑d10.75df=12mm取12mm機(jī)蓋與機(jī)座連接螺栓直徑d2(0.50.6)df=8mm取8mm連接螺栓d2的間距l(xiāng)335mm窺視孔蓋螺釘直徑d4(0.30.4)df=6-8mm取M6定位銷直徑d5.95mmdf、d2、d3至外機(jī)壁距離c122mmd1、d2至凸緣邊緣距離c218mm軸承旁凸臺半徑R1R1=C2=20外機(jī)壁至軸承座端

22、面距離L1c1+c2+(58)=50mm內(nèi)機(jī)壁至軸承座端面距離L2+c1+c2+(58)=60mm大齒輪頂圓與內(nèi)機(jī)壁距離11.2=12mm取12mm齒輪端面與內(nèi)機(jī)壁距離2=10mm取12mm機(jī)蓋、機(jī)座肋厚m1,mm1=m0.851=8.5mm,取8.5mm2、減速器附件的選擇，在草圖設(shè)計中選擇包括：軸承蓋，窺視孔，視孔蓋，壓配式圓形油標(biāo)，通氣孔，吊耳，吊鉤，螺塞，封油墊，氈圈等。九、潤滑與密封(潤滑與密封方式的選擇、潤滑劑的選擇)雙級減速器內(nèi)傳動零件(齒輪)采用浸油潤滑，因地級速齒輪速度為0.7m/s,采用的浸油深度應(yīng)為輪齒半徑。由于低級速v<2m/s,故減速器滾動軸承采用脂潤滑。十 小

23、結(jié) 這次的課程設(shè)計，我有了很大的收獲，通過系統(tǒng)地運(yùn)用學(xué)過的相關(guān)知識來解決問題，不管是在結(jié)構(gòu)設(shè)計中對零件的強(qiáng)度進(jìn)行校核，還是在用CAD繪圖的過程中，我發(fā)現(xiàn)都有很多要注意的細(xì)節(jié)。從按照雙級減速箱的傳遞效率、傳遞功率等工作要求到對各個零件進(jìn)行機(jī)構(gòu)設(shè)計，會涉及多方面的事情，既要考慮制造成本，又要考慮工藝的合理性，在計算的過程中也比較容易出錯。很多數(shù)據(jù)要通過設(shè)計手冊和課本查取，雖然在做這個課程設(shè)計的過程中會遇到很多的困難，但一步一腳印，不懂得地方經(jīng)過請教老師或者和同學(xué)討論之后，還是可以弄明白的。完成這次的課程設(shè)計，我發(fā)現(xiàn)設(shè)計一個零部件真不是一件容易的事情，零件的工作條件，工作要求和使用壽命都要考慮，當(dāng)然

24、，箱體的設(shè)計也是很有講究的，通過參考前人的經(jīng)驗(yàn)，能夠更好的設(shè)計出好的箱體。因?yàn)榱慵D和裝配圖都是用CAD來作圖的，便很好地復(fù)習(xí)了一遍CAD的使用操作功能。 g an employment tribunal claimEmployment tribunals sort out disagreements between employers and employees.You may need to make a claim to an employment tribunal if:· you don't agree with the disciplinary action yo

25、ur employer has taken against you· your employer dismisses you and you think that you have been dismissed unfairly.For more information about dismissal and unfair dismissal, see Dismissal.You can make a claim to an employment tribunal, even if you haven't appealed against the

26、 disciplinary action your employer has taken against you. However, if you win your case, the tribunal may reduce any compensation awarded to you as a result of your failure to appeal.Remember that in most cases you must make an application to an employment tribunal within three months of the date wh

27、en the event you are complaining about happened. If your application is received after this time limit, the tribunal will not usually accept it.If you are worried about how the time limits apply to you, take advice from one of the organisations listed under Further help.Employment tribunals are

28、 less formal than some other courts, but it is still a legal process and you will need to give evidence under an oath or affirmation.Most people find making a claim to an employment tribunal challenging. If you are thinking about making a claim to an employment tribunal, you should get help straight

29、 away from one of the organisations listed under Further help.If you are being represented by a solicitor at the tribunal, they may ask you to sign an agreement where you pay their fee out of your compensation if you win the case. This is known as a damages-based agreement. In England and

30、Wales, your solicitor can't charge you more than 35% of your compensation  if you win the case.If you are thinking about signing up for  a damages-based agreement, you should make sure you're clear about the terms of the agreement. It might be best to get advice from an experienced

31、 adviser, for example, at a Citizens Advice Bureau.  To find your nearest CAB, including those that give advice by e-mail, click on nearest CAB.For more information about making a claim to an employment tribunal, see Employment tribunals.The (lack of) air up there Watch mCayman Island

32、s-based Webb, the head of Fifa's anti-racism taskforce, is in London for the Football Association's 150th anniversary celebrations and will attend City's Premier League match at Chelsea on Sunday."I am going to be at the match tomorrow and I have asked to meet Yaya Toure," he t

33、old BBC Sport."For me it's about how he felt and I would like to speak to him first to find out what his experience was."Uefa has opened disciplinary proceedings against CSKA for the "racist behaviour of their fans" during City's 2-1 win.Michel Platini, pre

34、sident of European football's governing body, has also ordered an immediate investigation into the referee's actions.CSKA said they were "surprised and disappointed" by Toure's complaint. In a statement the Russian side added: "We found no racist insults from fans of CSKA.

35、"Age has reached the end of the beginning of a word. May be guilty in his seems to passing a lot of different life became the appearance of the same day; May be back in the past, to oneself the paranoid weird belief disillusionment, these days, my mind has been very messy, in my mind constantly

36、. Always feel oneself should go to do something, or write something. Twenty years of life trajectory deeply shallow, suddenly feel something, do it.一字開頭的年齡已經(jīng)到了尾聲?；蛟S是愧疚于自己似乎把轉(zhuǎn)瞬即逝的很多個不同的日子過成了同一天的樣子；或許是追溯過去，對自己那些近乎偏執(zhí)的怪異信念的醒悟，這些天以來，思緒一直很凌亂，在腦海中不斷糾纏。總覺得自己自己似乎應(yīng)該去做點(diǎn)什么，或者寫點(diǎn)什么。二十年的人生軌跡深深淺淺，突然就感覺到有些事情，非做不可了。T

37、he end of our life, and can meet many things really do?而窮盡我們的一生，又能遇到多少事情是真正地非做不可？During my childhood, think lucky money and new clothes are necessary for New Year, but as the advance of the age, will be more and more found that those things are optional; Junior high school, thought to have a crush o

38、n just means that the real growth, but over the past three years later, his writing of alumni in peace, suddenly found that isn't really grow up, it seems is not so important; Then in high school, think don't want to give vent to out your inner voice can be in the high school children of the

39、 feelings in a period, but was eventually infarction when graduation party in the throat, later again stood on the pitch he has sweat profusely, looked at his thrown a basketball hoops, suddenly found himself has already can't remember his appearance.童年時，覺得壓歲錢和新衣服是過年必備，但是隨著年齡的推進(jìn)，會越來越發(fā)現(xiàn)，那些東西根本就可有

40、可無；初中時，以為要有一場暗戀才意味著真正的成長，但三年過去后，自己心平氣和的寫同學(xué)錄的時候，突然就發(fā)現(xiàn)是不是真正的成長了，好像并沒有那么重要了；然后到了高中，覺得非要吐露出自己的心聲才能為高中生涯里的懵懂情愫劃上一個句點(diǎn)，但畢業(yè)晚會的時候最終還是被梗塞在了咽喉，后來再次站在他曾經(jīng)揮汗如雨的球場，看著他投過籃球的球框時，突然間發(fā)現(xiàn)自己已經(jīng)想不起他的容顏。Originally, this world, can produce a chemical reaction to an event, in addition to resolutely, have to do, and time.原來，這個

41、世界上，對某個事件能產(chǎn)生化學(xué)反應(yīng)的，除了非做不可的堅(jiān)決，還有，時間。A person's time, your ideas are always special to clear. Want, want, line is clear, as if nothing could shake his. Also once seemed to be determined to do something, but more often is he backed out at last. Dislike his cowardice, finally found that there are a l

42、ot of love, there are a lot of miss, like shadow really have been doomed. Those who do, just green years oneself give oneself an arm injection, or is a self-righteous spiritual.一個人的時候，自己的想法總是特別地清晰。想要的，不想要的，界限明確，好像沒有什么可以撼動自己。也曾經(jīng)好像已經(jīng)下定了決心去做某件事，但更多的時候是最后又打起了退堂鼓。嫌惡過自己的怯懦，最終卻發(fā)現(xiàn)有很多緣分，有很多錯過，好像冥冥之中真的已經(jīng)注定。那些

43、曾經(jīng)所謂的非做不可，只是青蔥年華里自己給自己注射的一支強(qiáng)心劑，或者說，是自以為是的精神寄托罷了。At the moment, the sky is dark, the air is fresh factor after just rained. Suddenly thought of blue plaid shirt; Those were broken into various shapes of stationery; From the corner at the beginning of deep friendship; Have declared the end of the enco

44、unter that haven't start planning. Those years, those days of do, finally, like youth, will end in our life.此刻，天空是陰暗的，空氣里有著剛下過雨之后的清新因子。突然想到那件藍(lán)格子襯衫；那些被折成各種各樣形狀的信紙；那段從街角深巷伊始的友誼；還有那場還沒有開始就宣告了終結(jié)的邂逅計劃那些年那些天的非做不可，終于和青春一樣，都將在我們的人生中謝幕。Baumgartner the disappointing news: Mission aborted. r plays an impor

45、tant role in this mission. Starting at the ground, conditions have to be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. The balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weather lives. It will climb higher than the tip of Mount Everest (5.5 miles/8.85 kilometers), drifting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and into the stratosphere. As he crosses the boundary layer (called the tropopause),e can