機(jī)械類(lèi)畢業(yè)設(shè)計(jì)-28馬力輪式拖拉機(jī)最終傳動(dòng)及驅(qū)動(dòng)軸設(shè)計(jì)、綠化灑水車(chē)設(shè)計(jì)（3噸重量）變速箱取力器及水泵傳動(dòng)

1、28馬力輪式拖拉機(jī)最終傳動(dòng)及驅(qū)動(dòng)軸設(shè)計(jì)摘要拖拉機(jī)是與各種作業(yè)機(jī)械配套的自走式動(dòng)力機(jī)械，是農(nóng)業(yè)機(jī)械化的主要 機(jī)械。在農(nóng)業(yè)中，他主要用以牽引和驅(qū)動(dòng)多種類(lèi)農(nóng)機(jī)具完成各項(xiàng)田間作業(yè)和 農(nóng)業(yè)運(yùn)輸。農(nóng)村經(jīng)濟(jì)日新月異鄉(xiāng)鎮(zhèn)企業(yè)蓬勃發(fā)展，城鄉(xiāng)交流不斷擴(kuò)大，道路 運(yùn)輸量急劇增加，所以運(yùn)輸車(chē)輛出現(xiàn)缺口。近年來(lái)，隨著拖拉機(jī)走入田間的 不斷深入，從作業(yè)種類(lèi)上由耕，耙，播擴(kuò)大到收獲，中耕，栽植，噴霧，打 捆等多個(gè)方面，與農(nóng)機(jī)具配套作業(yè)。農(nóng)用拖拉機(jī)正適合了其農(nóng)村的這種使用 條件：工作環(huán)境比較惡劣，農(nóng)村道路相對(duì)復(fù)雜，速度不高。在中國(guó)現(xiàn)有的生 產(chǎn)模式下，廣大農(nóng)民需要的還是中小型拖拉機(jī)，國(guó)內(nèi)市場(chǎng)對(duì)該檔產(chǎn)品的需求 量在不斷增長(zhǎng)。另外

2、和國(guó)外拖拉機(jī)生產(chǎn)廠家相比我國(guó)生產(chǎn)的拖拉機(jī)經(jīng)濟(jì)實(shí)惠， 價(jià)格只有國(guó)外同類(lèi)產(chǎn)品的一半甚至更少，因此，中小馬力拖拉機(jī)社會(huì)銷(xiāo)量和 保有量很大，傳動(dòng)系布置多種多樣。最終傳動(dòng)是傳動(dòng)系的重要組成部分之一，它的功用是進(jìn)一步增加傳動(dòng)系 的傳動(dòng)比，從而使拖拉機(jī)獲得所需的驅(qū)動(dòng)力。我這次設(shè)計(jì)的是輪式28馬力拖拉機(jī)的最終傳動(dòng)，我采用的是外置外嚙合 直齒圓柱齒輪式最終傳動(dòng)，軸采用了矩形花鍵軸。采用這種最終傳動(dòng)設(shè)計(jì)方 案，可以達(dá)到設(shè)計(jì)任務(wù)要求，并可保證拖拉機(jī)在工作中具有足夠的動(dòng)力輸出。關(guān)鍵詞：傳動(dòng)比，外嚙合，圓柱齒輪，花鍵軸度將進(jìn)一步提高。由于小型拖拉機(jī)的技術(shù)含量低，私營(yíng)企業(yè)的發(fā)展勢(shì)頭很猛。一拖公司正在積極研究調(diào)整策略，準(zhǔn)備

3、在保證國(guó)內(nèi)市場(chǎng)中的領(lǐng)先地位的 同時(shí)，穩(wěn)住非洲、東歐、東南亞的國(guó)際市場(chǎng)，積極深入國(guó)際市場(chǎng)進(jìn)行調(diào)研， 選擇合適的地方建立組裝廠、裝配中心。我設(shè)計(jì)的最終傳動(dòng)，就是適應(yīng)民族工業(yè)的發(fā)展和需要。由于我缺少工作 經(jīng)驗(yàn)并且對(duì)拖拉機(jī)最終傳動(dòng)了解的不夠透徹，難免在設(shè)計(jì)中出現(xiàn)一些錯(cuò)誤， 希望各位老師多加指正。第一章最終傳動(dòng)簡(jiǎn)介拖拉機(jī)最終傳動(dòng)的功用拖拉機(jī)最終傳動(dòng)的功用是進(jìn)一步增加傳動(dòng)系的傳動(dòng)比，從而使拖拉機(jī)驅(qū) 動(dòng)輪獲得所需的驅(qū)動(dòng)力，履帶拖拉機(jī)和某些輪式拖拉機(jī)的最終傳動(dòng)還用來(lái)提 高后橋的離地間隙。拖拉機(jī)最終傳動(dòng)的分類(lèi)最終傳動(dòng)按其傳動(dòng)形式分為：.外嚙合圓柱齒輪最終傳動(dòng)。.內(nèi)嚙合圓柱齒輪最終傳動(dòng)。.行星齒輪最終傳動(dòng)。拖拉機(jī)

4、最終傳動(dòng)的設(shè)計(jì)要求根據(jù)拖拉機(jī)最終傳動(dòng)必須具備的各項(xiàng)功能和使用的實(shí)際情況，對(duì)最終傳 動(dòng)的設(shè)計(jì)應(yīng)有以下的要求：.要有適當(dāng)?shù)膫鲃?dòng)比。.保證后橋處有足夠的離地間隙。.齒輪要具有較高的支承剛度，以保證在全齒寬上較好的嚙合。.靠近驅(qū)動(dòng)輪布置的最終傳動(dòng)尤其要有可靠的密封。XI第二章設(shè)計(jì)任務(wù)分析2. 1設(shè)計(jì)內(nèi)容近年來(lái)隨著拖拉機(jī)走入農(nóng)田的不斷深入，國(guó)內(nèi)市場(chǎng)對(duì)該檔產(chǎn)品的需求也 在不斷增長(zhǎng)，中小馬力拖拉機(jī)社會(huì)銷(xiāo)量和保有量很大，傳動(dòng)系布置多種多樣。 本課題旨分吸收成熟產(chǎn)品的優(yōu)點(diǎn)基礎(chǔ)上優(yōu)化設(shè)計(jì)出拖拉機(jī)的最終傳動(dòng)與驅(qū)動(dòng) 軸總成。2. 2主要技術(shù)指標(biāo)基本參數(shù)：發(fā)動(dòng)機(jī)28馬力，行駛速度1.530km/h, 6-8個(gè)前進(jìn)檔位輪

5、胎 型號(hào)：9.5-24o每位同學(xué)需完成總和不少于3張零號(hào)圖紙的結(jié)構(gòu)設(shè)計(jì)圖，裝配圖和零件 圖，其中應(yīng)包含用計(jì)算機(jī)繪制的有中等難度的1號(hào)圖紙一張以上。按要求，格式獨(dú)立撰寫(xiě)不少于12000字的設(shè)計(jì)說(shuō)明書(shū)，全部用計(jì)算機(jī)打 （編排要求到河南科技大學(xué)網(wǎng)站查：畢業(yè)設(shè)計(jì)說(shuō)明書(shū)（論文）的格式及規(guī)定）, 查閱與課題相關(guān)的文獻(xiàn)資料15篇以上，應(yīng)有中英文摘要，獨(dú)立完成10000 字以上印刷符號(hào)的外文翻譯。2. 3設(shè)計(jì)要求. 要有適當(dāng)?shù)膫鲃?dòng)比。保證后橋處有足夠的離地間隙。齒輪要具有較高的支承剛度，以保證在全齒寬上較好的嚙合?？拷?qū)動(dòng)輪布置的最終傳動(dòng)尤其要有可靠的密封。工作可靠性高。XII第三章最終傳動(dòng)設(shè)計(jì)方案的確定3.

6、 1設(shè)計(jì)方案的確定對(duì)最終傳動(dòng)的基本要求是：L要有適當(dāng)?shù)膫鲃?dòng)比；2.保證拖拉機(jī)后橋處 有足夠的離地間隙；3.最終傳動(dòng)直齒圓柱齒輪要有較高的支承剛度，以保證 在全齒寬上較好的嚙合；4.保證最終傳動(dòng)有可靠的密封。最終傳動(dòng)在拖拉機(jī) 上的布置如下圖(a)示1 一離合器2一變速箱 3停車(chē)制動(dòng)器4一中央傳動(dòng)和整速器5一行眈制動(dòng)器 6一終傳動(dòng)7一雙速的動(dòng)力輸出軸本次畢業(yè)設(shè)計(jì)是針對(duì)輪式拖拉機(jī)的最終傳動(dòng)，根據(jù)其傳動(dòng)形式采用外置 式外嚙合圓柱齒輪最終傳動(dòng)。3.2本次設(shè)計(jì)方案的說(shuō)明最終傳動(dòng)按其傳動(dòng)形式分為：外嚙合圓柱齒輪最終傳動(dòng)；內(nèi)嚙合圓柱齒輪最終傳動(dòng)；行星齒輪最終傳 動(dòng)三類(lèi)。而外嚙合圓柱齒輪最終傳動(dòng)按其結(jié)構(gòu)布置又可

7、分為外置式和內(nèi)置式 兩種。綜合這幾種最終傳動(dòng)的優(yōu)缺點(diǎn)，我采用外置式外嚙合圓柱齒輪最終傳 動(dòng)的原因如下：.外置式外嚙合圓柱齒輪最終傳動(dòng)與其他幾種最終傳動(dòng)相比較，有以下 優(yōu)點(diǎn)：(1)外置式外嚙合圓柱齒輪最終傳動(dòng)的左，右最終傳動(dòng)各自安裝在靠近 驅(qū)動(dòng)輪的單獨(dú)殼體內(nèi)，使最終傳動(dòng)成為一個(gè)獨(dú)立部件，便于拆裝和維修。XIII（2）這種結(jié)構(gòu)的主，從動(dòng)齒輪在殼體內(nèi)的支承簡(jiǎn)支梁式，對(duì)提高支承剛 度有利。（3）易于得到較高的農(nóng)藝離地間隙。（4）結(jié)構(gòu)簡(jiǎn)單，傳動(dòng)比較小，工作穩(wěn)定可靠。綜上所述所以我采用外置式外嚙合圓柱齒輪最終傳動(dòng)。XIV第四章最終傳動(dòng)及驅(qū)動(dòng)軸的設(shè)計(jì)計(jì)算整車(chē)主要參數(shù):整車(chē)裝備質(zhì)量:發(fā)動(dòng)機(jī)馬力：行駛速度范圍:

8、4.2外嚙合柱齒輪的主要參數(shù)確定:2000Kg28馬力1.5-30km/h9. 5-24輪胎輪胎型號(hào)：外嚙合圓柱齒輪最終傳動(dòng)由于嚙合線速度不高可采用圓柱齒輪，主要參 數(shù)包括總傳動(dòng)比im（取決于傳動(dòng)系總傳動(dòng)比的分配），中心距a和齒輪模數(shù)m 等。中心距a可根據(jù)經(jīng)驗(yàn)公式拖拉機(jī)設(shè)計(jì)手冊(cè)P1176式（6.7-1）Tj 從動(dòng)齒輪的計(jì)算轉(zhuǎn)矩（N.m）Ka中心距系數(shù)，中心距系數(shù)Ka 一般選擇Ka=1215,在傳動(dòng)比im小時(shí)，取較小值。對(duì) 履帶拖拉機(jī)Ka取大值。因?yàn)榻o定拖拉機(jī)為28馬力，所以拖拉機(jī)實(shí)際功率為P=28 馬力 X0. 735=20. 58KW發(fā)動(dòng)機(jī)轉(zhuǎn)速：N=2000r/min轉(zhuǎn)矩：XV輪胎型號(hào)參數(shù)：

9、9.5-24英寸 （1英寸=25. 4mni）輪胎半徑（充氣半徑）為：Q （9.5x2 4-24） ru ,R = x 25.4 = 546mm2在設(shè)計(jì)新拖拉機(jī)傳動(dòng)系時(shí)，如果無(wú)可皆鑒的載荷譜，又無(wú)充分的設(shè)計(jì)經(jīng) 驗(yàn)時(shí)，我們估算出傳動(dòng)系的名義計(jì)算載荷再乘以使用系數(shù)Ka,名義計(jì)算載 荷可按下面兩種方法計(jì)算取其中的較小者。.按發(fā)動(dòng)機(jī)的標(biāo)定轉(zhuǎn)矩轉(zhuǎn)換到被計(jì)算零件（取轉(zhuǎn)矩的一半）。拖拉機(jī)的總傳動(dòng)比是根據(jù)拖拉機(jī)的工作速度和發(fā)動(dòng)機(jī)的標(biāo)定轉(zhuǎn)矩轉(zhuǎn)速 來(lái)確定的。拖拉機(jī)設(shè)計(jì)手冊(cè)P983 ( 6. 1-1)取 Ka=13T. = TebR = 98.27x 256.6x0.85x- = 10716.87223 = 13x

10、/10716.8 286拖拉機(jī)設(shè)計(jì)手冊(cè)P988 ( 6. 1-10) 7總傳動(dòng)效率（按經(jīng)過(guò)四對(duì)齒輪和兩對(duì)軸承計(jì)算）圓柱齒輪的傳動(dòng)效率為0. 960. 98滾動(dòng)軸承的傳動(dòng)效率為0. 950. 9877 = 0.97 X 0.98 X 0.96 x 0.98 x 0.97 x 0.98 = 0.85Teb發(fā)動(dòng)機(jī)標(biāo)定轉(zhuǎn)矩2.按驅(qū)動(dòng)輪附著轉(zhuǎn)矩計(jì)算輸出軸的計(jì)算轉(zhuǎn)矩。t x Q（f）rd1 i I 77拖拉機(jī)設(shè)計(jì)手冊(cè)P988 （ 6. 1-11 ）n驅(qū)動(dòng)輪胎數(shù)（對(duì)于最終傳動(dòng)且在中央傳動(dòng)之后n=l）Q驅(qū)動(dòng)輪在胎內(nèi)壓力為lOOKPa時(shí)的乘載能力（可按拖拉機(jī)重量來(lái)計(jì)XVI算)Rd驅(qū)動(dòng)輪動(dòng)力半徑Rd=O. 935

11、R0附著系數(shù)輪式拖拉機(jī)取0.65拖拉機(jī)后輪的承載力為:= 1.8xlO3 x0.98x x = 6533按整機(jī)重2t,后輪分配三分之二車(chē)重，計(jì)算輸出軸的計(jì)算轉(zhuǎn)矩代數(shù)得=2306.2n x Q（/）Rd _ 6553 x 0.65 x 0.546 x 0.9351x0.94求得中心距為:172由于最終傳動(dòng)的傳動(dòng)比較大，齒輪和軸受載嚴(yán)重，但徑向尺寸受到輪惘 尺寸和離地間隙的限制而不能太大，為了在結(jié)構(gòu)緊湊的情況下，保證最終傳 動(dòng)齒輪有足夠的強(qiáng)度，外嚙和圓柱齒輪的最終傳動(dòng)常采用較大的齒寬b和較 少的齒數(shù)Z1。通常情況下在選擇主動(dòng)齒輪的齒數(shù)時(shí)一般選取12-15,齒寬b 和模數(shù)m之比一般為8-10,參照各

12、款拖拉機(jī)的模數(shù)的選取，并估算中心句距。mt =(0.4 0.6)圾=0.4盟2306.2 =5.3最終傳動(dòng)兩齒輪齒數(shù)和為69Zl = 13為主動(dòng)齒輪，Z2=56為從動(dòng)齒輪，實(shí)際傳動(dòng)比：i=56/13=4.308齒寬的選取是為了保證大齒輪的齒寬能全部參加嚙合以及提高小齒輪 的彎曲承載能力小齒輪的齒寬一般應(yīng)大于大齒輪的齒寬，選擇齒寬不宜過(guò)大, 否則在支撐剛度不足的情況下往往造成齒輪因局部偏載而出現(xiàn)過(guò)早損壞的現(xiàn) 象，所以齒輪的支撐剛度對(duì)齒輪的壽命影響極大。XVIIm=5, b= ( 8-10m 選取 bl=45,b2=404. 34. 3柱齒輪的結(jié)構(gòu)強(qiáng)度計(jì)算:1.圓柱齒輪各參數(shù)的計(jì)算：因?yàn)橥侠瓩C(jī)最終

13、傳動(dòng)工作載荷大固圓柱齒輪要進(jìn)行變位，這樣可以改善 嚙合條件，提高齒輪強(qiáng)度，避免根切和干涉.變位系數(shù)： A一（） =（% +x2）mXj + /=0.117-13 ux = 0.23517x2 = 0.335分度圓直徑：4 = m* Z1 =13x5 = 65 d2 = m- z2 =56x5 = 280標(biāo)準(zhǔn)中心距：mZ 5x69 1h ua = 172.522中心距變動(dòng)系數(shù)：172-172.5 八 1y = 0.12齒頂高變動(dòng)系數(shù)：k = X、+ %2 y 0.235 0.335 + 0.1 0尺頂高，齒跟高：XVIIIha = (h： + x k)m4* =1hf = (h； + c* +

14、x)mc= 0.25主動(dòng)齒輪：K =(1 + 0.235)x5 = 6.175hf =(1 + 0.25-0.3)x5 = 5.075從動(dòng)齒輪：42 =(1 0535)x5 = 3.325 C. Jhf2 =(1 + 0.25 + 0.535) x5 = 7.925尺頂圓直徑，尺根圓直徑：主動(dòng)齒輪：41 =4 +2% =65 + 2x6.175 = 77.35% =4 +2% =65 2x5.075 = 54.85JJ從動(dòng)齒輪：4/2 = 4 + 2% = 280 + 2x 3.325 = 286.65df? =d2+ 2hl2 = 280 2 x 7.925 = 264.15 J/2.齒輪傳

15、動(dòng)系的計(jì)算載荷在載荷的長(zhǎng)期，多次作用下傳動(dòng)系的齒輪，軸，軸承等零件出現(xiàn)疲勞損 壞，疲勞損壞是是傳動(dòng)零件的主要破壞形式，因此傳動(dòng)零件的強(qiáng)度計(jì)算是以 考慮疲勞損壞的耐久性計(jì)算為主，另外在特殊情況下(如在拖拉機(jī)起步驅(qū)動(dòng) 輪遭遇到突加阻力等)，傳動(dòng)零件可能受到很大的尖峰載荷，使零件的應(yīng)力超 過(guò)材料的強(qiáng)度極限而損壞。但這種損壞并不常見(jiàn)。在耐久性計(jì)算中根據(jù)拖拉機(jī)發(fā)動(dòng)機(jī)經(jīng)常處于滿(mǎn)載工況的特點(diǎn)，以發(fā)動(dòng)機(jī) 標(biāo)定轉(zhuǎn)矩Men作為發(fā)動(dòng)機(jī)傳遞給傳動(dòng)系的扭矩。各軸上零件的計(jì)算轉(zhuǎn)矩Mj, 等于Men乘以曲軸到該軸的傳動(dòng)比，以及期間的傳動(dòng)效率。在傳動(dòng)比較大的 排擋時(shí)就應(yīng)該按地面的附著能力來(lái)確定計(jì)算扭矩。計(jì)算時(shí)將兩種計(jì)算扭矩同

16、 時(shí)算出，選取較小的數(shù)值作為計(jì)算扭矩。XIXDESIGN OF FINAL DRIVE AND DRIVE SHAFT OF 28HP TRACTORABSTRACTTractor with a variety of echanical operations supporting dynamic self-propelled machinery, agricultural mechanization is the main machinery. In agriculture, he mainly used for traction and driving range to complete t

17、he form of field operations and agricultural transport. Changing rural economy booming township enterprises, expanding exchanges between urban and rural areas, road transport volume increased dramatically, So transport vehicles gap. In recent years, with the tractor into the field continues to deepe

18、n, from the types of operations by farming, harrows, sowing to harvesting expansion, plowing, planting, Spray, bundled in many aspects, such as, the form of matching operations. Farm tractor is suitable for its use of this rural conditions : work environment was quite poor, rural roads is relatively

19、 complex, speed is not high. In Chinas current production model, the majority of the needs of peasants or small tractors, on the domestic market stalls in the demand for products continues to increase. Tractor and other foreign manufacturers in China compared to the agricultural economic benefits pr

20、ices of similar foreign products only half or even less, and therefore, the community of small and medium-horsepower tractor sales and retain enormous capacity. Transmission layout varied.Final drive transmission system is an important component of one of its functions is to further increase the dri

21、ve transmission ratio, so that the tractor was driven.My current design are 28 horsepower wheeled tractors the final drive, I used the external Gear-final drive. Adopt this final drive design, the design can meet the requirements for this task, guarantee that the tractor will work with sufficient po

22、wer output.ii查表2-1傳動(dòng)系各軸的計(jì)算扭矩Mj轉(zhuǎn)向離合器軸（差速器半軸）齒輪的強(qiáng)度應(yīng)計(jì)算齒輪表面接觸強(qiáng)度和齒輪的彎曲強(qiáng)度，設(shè)計(jì)時(shí)為了初步估計(jì)齒輪強(qiáng)度以便進(jìn)行結(jié)構(gòu)設(shè)計(jì)，先作粗略計(jì)算齒輪的計(jì)算載荷圓周力Pj用下式求得：MM ji主動(dòng)齒輪上的計(jì)算扭矩f 主動(dòng)齒輪的節(jié)圓半徑1計(jì)算接觸強(qiáng)度一般只計(jì)算節(jié)點(diǎn)處的接觸應(yīng)力s= 0.418Pj.E,2 x （乙 + Z2）x .Z2 cos cc. sin oca = 20。E=206b齒寬.m模數(shù)最終傳動(dòng)輸入軸的計(jì)算轉(zhuǎn)矩：丁 =。5倉(cāng): G* 一JhqTj 最終傳動(dòng)主動(dòng)齒輪上的計(jì)算轉(zhuǎn)矩 rdg驅(qū)動(dòng)輪輪胎動(dòng)力半徑j(luò) 附著系數(shù)通常取為0.65Gj 拖

23、拉機(jī)的附著重量XXhq拖拉機(jī)最終傳動(dòng)的傳動(dòng)的傳動(dòng)效率lm 最終傳動(dòng)的傳動(dòng)比Q5倉(cāng)勘.65 2倉(cāng)09.8倉(cāng)IJ1935 0.546二 786.32A/m4.308 0.96計(jì)算齒輪的圓周力:計(jì)算齒輪的徑向力:FtX圓周力Z輸入軸扭矩2x786.3265*4主動(dòng)齒輪節(jié)圓直徑fi2圓周力d2從動(dòng)齒輪節(jié)圓直徑t2輸出軸扭矩 24.2KN2x2306.23280n6.47KNa計(jì)算主動(dòng)齒輪節(jié)點(diǎn)處的接觸應(yīng)力S/=0.418Pj.E-2 x (乙 + Z2)b.m.Z.Z? cos cc. sin a代數(shù)得024.2 x 103 x 20.6 x IO10 x 2 x (13 + 56)cr. = 0.41

24、8 JJ V 0.045 x 0.005 xl3x56xcos 200 x sin 20”1.63 5wb計(jì)算從動(dòng)齒輪節(jié)點(diǎn)處的接觸應(yīng)力Sjbj =0.41816.47 x IO3 x 20.6x IO10 x 2x (13 + 56) i 1.32 cr 0.04x0.005xl3x56xcos20 xsin 20L 卬查表機(jī)械設(shè)計(jì)P124表5-6得滲碳19002000Mpa 20CrMnTiXXI2齒根彎曲強(qiáng)度校核（拖拉機(jī)設(shè)計(jì)P67公式2 35）驗(yàn)算國(guó)產(chǎn)拖拉機(jī)普遍采用滲碳合金剛齒輪，其彎曲應(yīng)力一般不超過(guò) 280300朋7%對(duì)于線速度高（動(dòng)載荷較大）位于軸的懸臂端容易偏載的齒輪， 以及轉(zhuǎn)速高和

25、每一個(gè)齒輪在一轉(zhuǎn)中多次參與捏合的齒輪，應(yīng)采用較小的接觸 應(yīng)力和彎曲應(yīng)力，bj 20CrMnTi 400850MPaYsa 應(yīng)力較正系數(shù)（考慮了齒根圓腳所引起的應(yīng)力集中問(wèn)題）Y齒形系數(shù)查表拖拉機(jī)設(shè)計(jì)P68 圖248%=2.67Y1Fa2= 2.55L=L65圖278齒形系數(shù)Y和應(yīng)力校正系數(shù)Y“a）齒形系數(shù)Y b）應(yīng)力校正系數(shù)Y”（齒形角a=20頂高系數(shù)=徑向間隙系數(shù)c*=0.25.齒根圓角半徑P=0.38m）a齒輪1輸入軸主動(dòng)齒輪齒根 彎曲強(qiáng)度校核一1bmFa 1 sa 124.2 xlO30.045 x 0.005x 2.67 x 1.65 = 474Mpa xxn= 474x2,55x1,7

26、=461 MPa crvi b齒輪2輸出軸從動(dòng)齒輪齒根彎曲強(qiáng)度校核P2b,n216.47xl03x 2.55 xl.7 = 351 MPa 八r 2.67 x 1 .651=357 x= 363Mpei Fcr 1L 卬r 2.67 x 1 .651=357 x= 363Mpei =l. 4h非定位軸肩高度一般取12.5mm,對(duì)于軸的長(zhǎng)，取決于軸上零件的寬度 以及他們的相對(duì)位置，考慮到鑄造誤差及裝配時(shí)留有必要的間隙，取齒輪端 面至箱壁間的距離a=15滾動(dòng)軸承與箱壁s = 5mm,軸承處箱體突緣寬度，應(yīng)按 箱蓋與箱體連接螺栓，尺寸結(jié)構(gòu)要求確定.軸和軸上零件的結(jié)構(gòu)，工藝及軸上零件的安裝布置等對(duì)軸的

27、強(qiáng)度有 很大影響，所以應(yīng)進(jìn)行充分考慮，以提高軸承的承載能力，減小軸的尺寸和 機(jī)器的重量，降低制造成本，.軸的強(qiáng)度驗(yàn)算先做出軸的受力計(jì)算簡(jiǎn)圖(即力學(xué)模型)如圖所示，取集中載荷作用于 軸的中點(diǎn)，齒輪上作用力的大小最終傳動(dòng)輸入軸的計(jì)算轉(zhuǎn)矩：T =。-5倉(cāng)于Gj ?工jJ hq TOC o 1-5 h z T0.5倉(cāng)9.65 2倉(cāng)UCP 9.8倉(cāng)的.546 0.935一T; = = 78o.327vmJ4.308 0.96計(jì)算齒輪的圓周力：l 27；2x786.32-(-叱-F. = L = 24.2KN“4651)垂直平面V內(nèi)受力：Fq + F2 = Ftix tana = 24.2xlO3 x t

28、an 20 =7863KN41.5& =43酩綜合兩式可得：FvX = 400IN, FV2 = 3862NMh = Ki x / = 4001 x 41.5 x m=166.04N.”2)水平面H內(nèi)受力:XXIV41.5% =437 ri 1ri ZFH + FH2 = 24.2 x IO3綜合兩式得：心 二12314.8N,/2 =11885.2NM 二b x = 12314.8 X 41.5 X 1。-3 = 5 n 06N.M u Ln 1合成彎矩的計(jì)算Mb=1W（Mb2）2 = 7（166.04）2+（511.06）2 = 537.36畫(huà)出彎矩圖因單向回轉(zhuǎn)轉(zhuǎn)矩為脈動(dòng)循環(huán)，取。=6則截

29、面b處當(dāng)量彎矩為Mh =如萬(wàn) = J（537.36y+（）2 = 715.08N根截面b為危險(xiǎn)截面：查表機(jī)械設(shè)計(jì)12-2齒輪的主要力學(xué)性能，許用應(yīng)力及用量，選擇45#調(diào)質(zhì)鋼 a_ib = 10MPaXXVIAXXN9O ILC- 20|a|a j1 JNizO 99 L SA JlwTno8一Etz一() 一至一1 甲 vjI,LarIA J,A L匚二號(hào)Q8,Liz74.5驅(qū)動(dòng)軸的確定與計(jì)算:L大齒輪上作用的力:4=16470(N)Fr = Ft tan 20 = 5994.59(N)T = 2306.32N加2 .求軸承的支撐反力: 驅(qū)動(dòng)軸受力分析如圖:水平面上的支反力和彎矩圖：=幾 x

30、77.5 = 04207V7,145 + 77.5=16470-10420 = 6050?7Ft水平面上彎矩：M x/ = 10420 x0.045 = 468.9N機(jī)八 468. 9c）垂直面上支反力和彎矩圖:XXVII% X174 + % x5L8 = F2 X 129.3連立各式得% x 174+ % x 122.5 = 457%FzFz= 2x103x-x-x9.8 = 6533.3A3 2Fvx = 2347.562 =7077.8FviFviFz畫(huà)出垂直彎矩圖:Mh?=FVxl =2347.5x0.045 = 105.6Nm U 乙V JLM, =Fvlxl =2347.5x0,1

31、22286.4L 1V 1.286. 4Nmd）合成彎矩圖：Mb 4（丹）2 +（監(jiān)2 ）2設(shè)力（丹）2+（% 了Mh（M hl）2 + （M h2）2 = J（468.9）2 + （105.6）2=480.6NmMc 4（心）2+（監(jiān)2）2 = J（286.4）2+（105.6）2 305 24畫(huà)合成彎矩圖：XXVIII480.6Nm因單向回轉(zhuǎn)，視轉(zhuǎn)矩為脈動(dòng)循環(huán)：Mvb 力（監(jiān)+皿y=J（480.6）2 +（0.6x2306.32）2 x 1497.8M?MVc =7（Mc）2+（7；）2 = J（305.24）2 +（0.6x2306.32）2 /45lo6Nw計(jì)算彎矩圖：XXIXKey

32、words: Transmission ratio, External, cylindrical gears, spline shafthi截面b為危險(xiǎn)截面。查表12-2軸的常用材料，主要力學(xué)性能，許用彎曲應(yīng)力及用途機(jī) 械設(shè)計(jì)P2586_力=70M2a 選材料40Cr調(diào)質(zhì)鋼。鍵的校核：花鍵軸抗彎抗扭截面系數(shù)計(jì)算公式：w =不壯4 +(D-d)(D + d)2 Zb / 32D矩形花鍵查機(jī)械設(shè)計(jì)手冊(cè)P256 ( 3. 2. 3)表3-3-16選擇花鍵規(guī)則為8x62x68x12計(jì)算花鍵軸抗彎抗扭截面系數(shù)W =不4 +(。一 d)(。+ d)2 z可 / 32D= 3,14 x 624+(68 -

33、62)(68 + 62)2 x 8x12/32x68=25795.9按彎扭合成應(yīng)力校合成應(yīng)力校核軸的的強(qiáng)度)截面b當(dāng)量彎矩最大，故截面C可能為危險(xiǎn)截面已知M = 1497. 8Nm,查表得 12-2 得.仍=70叱M 1497.8xl03 “小5 = = 50.92 8000 (h)= 9136.6 (h) 8000 (h)壽命滿(mǎn)足要求。4.8輸出軸錐滾子軸承的校核根據(jù)已知直徑初選圓錐滾子軸承7214E型軸承和7211E型 查表：15-7圓錐滾子軸承摘自（GB297-84）（1 =5 5 mm Cr = 86.5x 103Nd-=70mm Cr = 125x 103N1）確定計(jì)算軸上的外載荷：

34、由驅(qū)動(dòng)軸校核得fhFH2fhFH2= 10420N=6050NFy = 2347.5NF =7077.8Nr2）確定軸承的支承反力:friFH1+Fvi2P10681.2NFR2FH2+ FV22P931L2N%=150634得查表 1I f!%=15。3832%=150634得查表 1I f!%=15。3832熊15.6=3.58Y = 0.4= 1.43Y = 0.4= 1.43e = 1.5xctga = 0.09XXXIg = 3734.7 N2YFS2出 = 3255.7N 2Y3）計(jì)算心1，乙） 由于外門(mén)氣。對(duì)軸承2壓緊 Al AZJI J /Fa=Fs =3734.7NFAl=F

35、Sl+Fa=FAi上=0.349 eFR2X=0. 4 Y=l. 4/p2=l.3P = fp(XFR + YFA)q =13885.6小時(shí)%=8953.06小時(shí)所以驅(qū)動(dòng)軸圓錐滾子軸承壽命足夠。XXXII第五章結(jié)論我們的畢業(yè)設(shè)計(jì)結(jié)束了，這不僅僅是對(duì)我們所學(xué)專(zhuān)業(yè)知識(shí)的一次綜合檢 驗(yàn)，也是對(duì)大學(xué)期間所學(xué)全部知識(shí)的一次全面檢驗(yàn)。我所設(shè)計(jì)的中小型拖拉機(jī)是對(duì)目前市場(chǎng)上流行的中小型拖拉機(jī)的改進(jìn) 與提高。在設(shè)計(jì)中我們參照了拖廠的一些拖拉機(jī)，在他們的基礎(chǔ)上進(jìn)行設(shè)計(jì) 改進(jìn)。在設(shè)計(jì)中我感到對(duì)所學(xué)專(zhuān)業(yè)知識(shí)了解的并不深入，再加上缺少實(shí)踐經(jīng) 驗(yàn)，所以在設(shè)計(jì)中我遇到了不少困難。雖然在郝紅周老師的耐心指導(dǎo)和幫助 下，我完成

36、了畢業(yè)設(shè)計(jì)要求的任務(wù)，但我的設(shè)計(jì)當(dāng)中難免存在這樣或那樣的 不足之處。本次畢業(yè)設(shè)計(jì)，給了我們一次全面的實(shí)踐機(jī)會(huì)。通過(guò)設(shè)計(jì)中對(duì)知識(shí)的綜 合運(yùn)用，加深了我們對(duì)所學(xué)知識(shí)的理解，也鍛煉了我們獨(dú)立分析，解決問(wèn)題 的能力。這對(duì)于我們今后的學(xué)習(xí)，工作都有很大的幫助。XXXIII參考文獻(xiàn)1彭文生，李志明，黃花梁 主編.機(jī)械設(shè)計(jì).北京：高等教育出版 社，2002年8月2陳家瑞 主編.汽車(chē)構(gòu)造（上、下）.第2版.北京：機(jī)械工業(yè)出版社，2006年1月3王望予 主編.汽車(chē)設(shè)計(jì).北京：機(jī)械工業(yè)出版社，2005年7月4機(jī)械電子工業(yè)部洛陽(yáng)拖拉機(jī)研究所主編.拖拉機(jī)設(shè)計(jì)手冊(cè)（上、下 冊(cè)）.機(jī)械工業(yè)出版社，19945張龍 主編.機(jī)

37、械設(shè)計(jì)課程手冊(cè).北京：國(guó)防工業(yè)出版社，2006年56日自動(dòng)車(chē)技術(shù)會(huì)小林明等 主編.汽車(chē)工程手冊(cè).北京：機(jī)械工業(yè) 出版社，1984年4月7王昆 主編.機(jī)械設(shè)計(jì)課程設(shè)計(jì).北京：高等教育出版社，2005年12 月8余志生.主編.汽車(chē)?yán)碚?北京：機(jī)械工業(yè)出版社，20009徐潮.主編.機(jī)械設(shè)計(jì)手冊(cè).北京：機(jī)械工業(yè)出版社，199110汽車(chē)工程手冊(cè)編輯委員會(huì).主編.汽車(chē)簡(jiǎn)明手冊(cè)，北京：人民交 通出版社，200111周孔亢.主編.1.5噸級(jí)農(nóng)用運(yùn)輸車(chē)的技術(shù)分析.拖拉機(jī).1992第一期12林寧.主編.汽車(chē)設(shè)計(jì).北京：機(jī)械工業(yè)出版社，199913金國(guó)棟.主編.汽車(chē)概論.北京.機(jī)械工業(yè)出版社，200014張洪圖.主

38、編.汽車(chē)構(gòu)造（底盤(pán)部分）.北京：北京理工大學(xué)出版社， 199615吉林工業(yè)大學(xué)汽車(chē)教研室編.汽車(chē)設(shè)計(jì).北京：機(jī)械工業(yè)出版社， 199016吉林工業(yè)大學(xué)拖拉機(jī)教研室編.拖拉機(jī)構(gòu)造.機(jī)械工業(yè)出版社出 版，1974.XXXIV致謝首先感謝學(xué)校為我們提供了畢業(yè)設(shè)計(jì)這次難得的鍛煉機(jī)會(huì)，使我們能夠 在走出校門(mén)參加工作之前對(duì)自己大學(xué)期間所學(xué)的基礎(chǔ)知識(shí)和專(zhuān)業(yè)知識(shí)進(jìn)行了 一次綜合的訓(xùn)練，為將來(lái)走上工作崗位打好了基礎(chǔ)。同時(shí)，感謝我們的各位 專(zhuān)業(yè)課老師為我們提供了良好的設(shè)計(jì)環(huán)境。學(xué)校圖書(shū)館和我的指導(dǎo)老師郝紅 周老師也為我們提供了許多參考資料。我的指導(dǎo)老師郝紅周老師還帶領(lǐng)我們 到拖廠觀看了實(shí)物。在這次為期兩個(gè)月的畢業(yè)

39、設(shè)計(jì)中，郝紅周老師在繁忙的工作之余，對(duì)我 們?cè)O(shè)計(jì)的各個(gè)階段，各個(gè)方面提出了許多有用的意見(jiàn)和建議，我們表示萬(wàn)分 的感謝，可以說(shuō)本次畢業(yè)設(shè)計(jì)的順利完成與郝紅周老師的辛勤指導(dǎo)是分不開(kāi) 的。本次設(shè)計(jì)還得到了同組同學(xué)的大力支持和幫助，在此也向他們表示衷心 的感謝。Powering profitsHow PSA is extracting more performance and profit from a new 2.2-litre engineThe ongoing success of the co-operation between PSA Peugeot Citroen and Ford (Se

40、e Feature, page 38) is further illustrated by the introduction of an all-new 2.2-litre diesel engine for passenger cars. The inline four-cylinder engine was not included in the original framework agreement, signed in 1998. Its development suggests that the two groups are doing well out of the partne

41、rship.The new 2.2-litre diesel engine resulting from the technical alliance between PSA and Ford was designed to meet an ambitious target. It had to offer the driveability of the best 2.5-litre engines on the market as well as better fuel efficiency and emissions levels.xxxvThe engine will be used o

42、n a number of platforms for upper mid-rang and executive cars produced by both manufacturers. The engineers also faced the challenge of improving pedestrian protection to meet incoming European legislation and to improve the engines noise characteristics.Because downsizing had proved effective in ea

43、rlier phases of their co-operation, PSA and Ford opted to keep the new engine small. They set the displacement at 2.2-litres to reduce fuel consumption and carbon dioxide emissions, without sacrificing any of its performance features.The engine takes some interesting approaches in its design . Its e

44、xtreme conventional combustion system (ECCS) features a combustion chamber design that reduces emissions by 30 percent while improving performance and noise.The combustion chamber has a large diameter and low compression ratio, which produces a more uniform air/fuel mix. The size of the combustion c

45、hamber limits the amount of fuel in contact with the walls. This makes combustion more efficient.The pistons5 geometry had to be altered to create a 25 percent larger diameter combustion chamber compared with the previous engine generation. To withstand the extra stress and heat, the pistons had to

46、be aluminium. The metal has very high mechanical and thermal properties.The special geometry also significantly reduced swirl in the combustion chamber, thereby reducing heat loss to the walls and improving the engine 9s efficiency. As a result, fuel efficiency under all driving conditions improved

47、by 2 percent compared to the previous generation.Remarkably, the new ECCS system did not require any changes in the production tooling for PSAs DW family of engines. Parts are common to the other engines produced in this plant.The engines common rail is a third-generation Bosch system that operates

48、at a pressure of 1800 bar. The system uses piezoelectric injectors with seven 135 /Lim nozzles. These can make up to six injections per cycle, make fuel dosing more precise. This in turn enhances management of the introduction rate, the ratio of the amount of diesel injected to the injection spray i

49、s finer, whichxxxvi reduces emissions, since the air/diesel mix is more uniform.All the cars powered by the new engine will be equipped with maintenances-based filter technology, while Ford will use a catalyst-based filter.To enhance drive ability, particularly the torque delivered at low revs, turb

50、os were essential. PSA engineers developed two turbo charging systems for different versions of the engine in partnership with turbo firm Honeywell.The more powerful 125KW version uses a parallel sequential dual turbo. This reaches a peak torque of 400Nm at just 1750rpm. Using a small, low-inertia t

51、urbo makes the same size kicks in at 2700rpm. Both turbos are controlled by the engine management system.A second version, which can produce between 115 and 125 KW, uses a single variable geometry turbo. This reaches 400Nm at 2000rpm and will be used for applications that do not require the bi-turbo

52、 boost at low engine speed. Electrical control enables precise, fast management of the turbos variable geometry to optimize boost pressure across the entire operating range.Despite the extra kit on the engine, the overall engine height is 40mm less than its predecessor. Its compact size will allow i

53、t to be used in a greater number of vehicles by the manufacturers. It also makes the engine less likely to injure a pedestrian in the event of an accident. Performance, rather than pedestrian safety was the main priority, however. The reduction an size is the result of extensive re-engineering work

54、on the engines top end.The cylinder head has a single cooling flow, which also reduces heat loss, and is made from an aluminum-copper alloy. The properties of the material give better thermo-mechanical performance. The uniform water system cools the cylinder head precisely, reducing the amount of wa

55、ter used and simplifying the process.A double-wall crankcase was developed for the project to reduce the noise radiated from the engine by three decibels; significant in terms of customer perception, says PSA. A fast response throttle intake system is actuated when engine is shut-off to avoid any vi

56、bration when the driver stops the car. And two counter-rotating balance shafts keep vibration on the inline unit to a minimum.xxxvnThe engine will be manufactured at PSAs tremery plant in France, the worlds largest diesel factory. In 2005, its 4637 engineers and production workers produced 1.2 milli

57、on units.The facility uses batch production to avoid assembly errors caused by changing from one model to another. The batches are very large with several hundred identical engines following each other on the line.The 2.2-litre unit will be subject to the same “red card“ sysem as others at the plant

58、. Engines are checked after each assembly station. If a defect is spotted, the complete engine is scrapped. No reworking can be performed on the line, so that high quality is built into every engine from the outset. It sounds costly, but PSAs research has shown that the reduction in warranty costs g

59、reatly outweighs any additional production costs.The overall investment for designing and producing the new engine is EUR 212m (RMB 2.1bn). research and development costs came to EUR 127m (RMB 1.3bn). By using existing tooling with only specific technical improvements, production investment was limi

60、ted to just EUR 85m (RMB 850m).More than 300 people will be assigned to production of the engine. Built on the same line as PSAs 2.0-litre engine, the use of existing tooling and processes meant that it took just 3300 hours of training for the operators to adapt their skills to the changes in their