527 履帶拖拉機(jī)變速器改進(jìn)設(shè)計(jì)Ⅱ（有cad圖）,527,履帶拖拉機(jī)變速器改進(jìn)設(shè)計(jì)Ⅱ（有cad圖）,履帶,拖拉機(jī),變速器,改進(jìn),改良,設(shè)計(jì),cad 履帶拖拉機(jī)變速器改進(jìn)設(shè)計(jì)Ⅱ 摘 要 本次設(shè)計(jì)任務(wù)為：履帶拖拉機(jī)變速器的改進(jìn)設(shè)計(jì)。 變速箱的結(jié)構(gòu)對(duì)拖拉機(jī)的動(dòng)力性、經(jīng)濟(jì)性、操縱的可靠性與輕便性、工作噪聲等都有直接影響。變速箱主要用來(lái)改變發(fā)動(dòng)機(jī)傳到驅(qū)動(dòng)輪上的轉(zhuǎn)矩和轉(zhuǎn)速，目的是在起步、爬坡、轉(zhuǎn)彎、加速等各種行駛工況下，使汽車(chē)獲得不同的牽引力和速度，同時(shí)使發(fā)動(dòng)機(jī)在最有利的工況范圍工作，設(shè)有空檔和倒檔，并設(shè)有動(dòng)力輸軸。 為適應(yīng)農(nóng)業(yè)耕作的復(fù)雜工況，要求變速箱采用多檔位,以使變速箱有較寬的速比范圍，以使拖拉機(jī)能高效率高質(zhì)量地完成各種作業(yè)。該變速器采用手動(dòng)嚙合套換檔機(jī)構(gòu)，空間三軸布置方式，結(jié)構(gòu)緊湊。 本次設(shè)計(jì)按照傳統(tǒng)設(shè)計(jì)方法，本著半經(jīng)驗(yàn)半理論的設(shè)計(jì)原則通過(guò)類(lèi)比法確定方案，參照已有變速箱結(jié)構(gòu)，最后以機(jī)械零件的強(qiáng)度和剛度理論對(duì)確定的形狀和尺寸進(jìn)行必要的計(jì)算和校核，以滿(mǎn)足約束條件，進(jìn)而縮短設(shè)計(jì)周期，降低設(shè)計(jì)成本。 關(guān)鍵詞：拖拉機(jī)，變速箱，嚙合套，改進(jìn)設(shè)計(jì) IMPROVED DESIGN Ⅱ OF TRACKED TRACTOR TRANSMISSION ABSTRACT This design is an improving design of the tractor transmission. The structure of the transmission has direct effect on the tractor’s traction performance and economy performance as well as its reliability, working noise and so on. Transmission is mainly used to change the engine torque and speed reached on the driving wheel, the aim is to acquire different traction and speed in various driving conditions like starting, climbing, turning and accelerating. At the same time the engine can work in optimum condition. The transmission has reverse gear ，zero gear and power transmission shaft. To meet the complex farming conditions, the transmission should have a multi-gear so that the transmission speed ratio can be changed in a wide scope. Then the tractor can complete all kinds of operation efficiently and high-quality. The transmission adopts the manual shift meshing sets, triaxial space layout. And its structure is compact. The design of transmission uses the traditional design method. Based the semi-empirical and semi-theoretical design principles, the drive scheme is determined by analogy. In order to meet the conditions, shorten the design cycle and reduce design costs, the shape and size of transmission are calculated and checked by the mechanical parts strength and stiffness theory. Key words: tractor, transmission, meshing sleeve, improved design 符 號(hào) 說(shuō) 明 發(fā)動(dòng)機(jī)標(biāo)定功率， 發(fā)動(dòng)機(jī)標(biāo)定轉(zhuǎn)速， 傳動(dòng)系總傳動(dòng)比 履帶驅(qū)動(dòng)輪半徑， 拖拉機(jī)理論工作速度， km/h 變速器的傳動(dòng)比 中央傳動(dòng)比 最終傳動(dòng)比 各檔之間的公比 A 中心距， T 軸及軸所承受的轉(zhuǎn)矩， 最大地面驅(qū)動(dòng)力， 地面支反力， 附著系數(shù) 整車(chē)總質(zhì)量， g 重力加速度， 中心距系數(shù) m 模數(shù)， 彎曲應(yīng)力， 彎矩， 軸承基本額定壽命用小時(shí)來(lái)表示， 當(dāng)量動(dòng)載荷， 壽命指數(shù)，球軸承=3，滾子軸承=10/3 目 錄 第一章 前言............................................1 第二章 變速箱的結(jié)構(gòu)分析................................3 §2.1概述.....................................3 §2.2 變速箱的總體結(jié)構(gòu)分析.......................3 §2.2.1 傳動(dòng)機(jī)構(gòu)布置方案分析 .......................4 §2.2.2 零、部件機(jī)構(gòu)方案分析.......................5 §2.3 變速箱的總體結(jié)構(gòu)方案的確定.................6 第三章 變速箱主要參數(shù)的確定...........................7 §3.1傳動(dòng)系傳動(dòng)比的計(jì)算...........................7 §3.1.1 傳動(dòng)系總傳動(dòng)比的計(jì)算........................7 §3.1.2 總傳動(dòng)比與各部件間傳動(dòng)比的關(guān)系..............7 §3.2 變速箱各檔位傳動(dòng)比的初步確定..................8 §3.2.1 理論車(chē)速的分段及對(duì)應(yīng)的傳動(dòng)比................8 §3.2.2 變速箱各區(qū)段傳動(dòng)比的確定....................8 §3.3 中心距和模數(shù)的確定........................10 §3.3.1 中心距A的確定.............................11 §3.3.2 模數(shù)m的確定..............................11 §3.4 變速箱各傳動(dòng)齒輪齒數(shù)的確定...................11 §3.4.1 傳動(dòng)齒輪齒數(shù)的初步確定.....................11 §3.4.2 齒數(shù)及傳動(dòng)比的最終確定.....................13 §3.4.3 8+4檔變速箱各檔的速比和速度..............13 §3.5 本章小結(jié)..................................14 第四章 齒輪的設(shè)計(jì)計(jì)算.................................15 §4.1概述.........................................15 §4.2齒輪主參數(shù)的選擇.............................15 §4.2.1 齒輪副中心距...............................15§4.2.2 齒形角.....................................15 §4.2.3齒寬系數(shù)..................................15 §4.2.4 齒輪基本參數(shù)..............................15 §4.2.5 變位齒輪參數(shù)的確定.........................17 §4.3 齒輪強(qiáng)度的校核.................................17 §4.3.1 拖拉機(jī)齒輪常用的加工方法..................18 §4.3.2許用彎曲應(yīng)力的確定.........................18 §4.3.3 輪齒彎曲應(yīng)力的求解.......................18 §4.3.4 齒輪齒寬的確定...........................19 第五章 軸的設(shè)計(jì)計(jì)算...........................20 §5.1軸結(jié)構(gòu)的初步選定...........................20 §5.2 軸的強(qiáng)度校核...............................21 §5.2.1軸T1的強(qiáng)度校核..........................21 §5.2.2軸T2的強(qiáng)度校核..........................26 §5.2.3軸T3的強(qiáng)度校核..........................30 §5.3 本章小結(jié)................................34 第六章 軸承的選用和壽命計(jì)算...........................35 §6.1軸承的選用.................................35 §6.2滾動(dòng)軸承的壽命的計(jì)算........................35 §6.2.1 軸承的平均轉(zhuǎn)速............................35 §6.2.2軸承的基本額定壽命........................36 §6.3本章小結(jié).................................37 第七章 結(jié) 論........................................38 參考文獻(xiàn)...............................................39 致謝...................................................40 V