【正文】 度L 就是行星齒輪在其軸上的支撐長(zhǎng)度通常取 ㎜ 37 ㎜ 38 式中 差速 器穿司的轉(zhuǎn)矩 行星齒輪數(shù) 行星齒輪支撐面中心點(diǎn)到錐頂?shù)木嚯x㎜ 支撐面的許用擠壓應(yīng)力取為 98 34 差速器齒輪的幾何尺寸計(jì)算與強(qiáng)度校核 1 差速器齒輪的幾何尺寸計(jì)算 表 31 為專用軟件計(jì)算出的汽車差速器用直齒錐齒輪的幾何尺寸具體數(shù)據(jù) 表 31 汽車差速器直齒錐齒輪的幾何尺寸計(jì)算用表 單位㎜ 序號(hào) 計(jì)算公式 注釋 1 行星齒輪齒數(shù) 2 半軸齒輪齒數(shù) 3 模數(shù) 4 齒面寬 5 齒工作高 6 齒全高 7 壓力角 8 軸交角 9 節(jié)圓直徑 10 節(jié)錐角 11 節(jié)錐距 12 周節(jié) 13 齒頂高 14 齒根高 15 徑向間隙 16 齒根角 17 面錐角 18 根錐角 19 外圓直徑 20 節(jié)錐頂點(diǎn)至齒輪外緣距離 21 理論弧齒厚 22 齒側(cè)間隙 23 弦齒厚 24 弦齒高 2 差速器錐齒輪強(qiáng)度計(jì)算 差速器齒輪的工作情況與主減速器齒輪不同一是差速器的齒輪尺寸較小而承受的載荷有較大二是差速器齒輪并非經(jīng)常處于嚙合狀態(tài)只有在左右兩車輪轉(zhuǎn)速不同時(shí)行星齒輪才有自轉(zhuǎn)運(yùn)動(dòng)行星齒輪和半軸齒輪才有嚙合運(yùn)動(dòng)否則行星齒輪只起等臂推 力桿的作用因此對(duì)差速器齒輪主要進(jìn)行彎曲強(qiáng)度計(jì)算 彎曲應(yīng)力按下式計(jì)算 39 92854 980 式中 差速器一個(gè)行星齒輪給予一個(gè)半軸齒輪的轉(zhuǎn)矩 計(jì)算轉(zhuǎn)矩 差速器心齒輪數(shù)目 半軸齒輪齒數(shù) 見上式 212 下說(shuō)明 計(jì)算汽車差速器輪齒彎曲應(yīng)力的綜合系數(shù)由《汽車車橋設(shè)計(jì)》圖 49～圖411 查取 按兩種計(jì)算轉(zhuǎn)矩中心的較小者進(jìn)行計(jì)算彎曲應(yīng)力不大于 980 根據(jù)計(jì)算結(jié)果可知設(shè)計(jì)符合要求 第 4 章 驅(qū)動(dòng)車輪的傳動(dòng)裝置 41 車輪傳動(dòng)裝置簡(jiǎn)介 驅(qū)動(dòng)車輪的傳動(dòng)裝置的基本功 用是將轉(zhuǎn)矩由差速器半軸齒輪傳給驅(qū)動(dòng)車輪在斷開式驅(qū)動(dòng)橋和轉(zhuǎn)向驅(qū)動(dòng)橋中其車輪傳動(dòng)裝置主要包括半軸和萬(wàn)向傳動(dòng)裝置在非斷開式驅(qū)動(dòng)橋中車輪傳動(dòng)裝置的主要零件是半軸 42 半軸的型式和選擇 普通整體式驅(qū)動(dòng)橋的半軸根據(jù)其外端的支撐型式或受力狀況的不同而分為三種型式半浮式 34 浮式和全浮式 根據(jù) DD6990 中型客車的結(jié)構(gòu)特點(diǎn)選擇其半軸的型式為全浮式半軸如圖 41全浮式半軸的特點(diǎn)是半軸外端的凸緣用螺釘與輪轂相聯(lián)而輪轂又借用兩個(gè)圓錐滾子軸承支撐在驅(qū)動(dòng)橋殼的半軸套管上理論上說(shuō)半軸只承受轉(zhuǎn)矩作用于驅(qū)動(dòng)輪上的其它反力和彎矩全由殼來(lái)承受但 由于橋殼變形輪轂與差速器半軸齒輪不同心半軸法蘭平面向?qū)ζ漭S線不垂直等因素會(huì)引起半軸的彎曲變形由此引起的彎曲應(yīng)力一般為 5～ 70 全浮式半軸其工作可靠廣泛應(yīng)用于輕型以上的各類汽車 圖 41 全浮式半軸 43 半軸的設(shè)計(jì)與計(jì)算 如前所述本方案采用全浮式半軸其設(shè)計(jì)過(guò)程如下按最大附著力所決定的縱向力 式中滿載靜止汽車的驅(qū)動(dòng)橋?qū)λ降孛娴妮d荷 質(zhì)量轉(zhuǎn)移系數(shù) 輪胎與地面的附著系數(shù) 則按發(fā)動(dòng) 機(jī)最大轉(zhuǎn) 矩及傳 動(dòng)系最 低擋傳動(dòng) 比計(jì)算 所得的 縱向力 42 式中差速器轉(zhuǎn)矩分配系數(shù)發(fā)動(dòng)機(jī)最大轉(zhuǎn) 矩 傳動(dòng)系最低擋傳動(dòng)比 汽車傳動(dòng)系效率 驅(qū)動(dòng)車輪滾動(dòng)半徑 則 從而半軸的計(jì)算轉(zhuǎn)矩為 上式中取上述計(jì)算結(jié)果中的小者 在設(shè)計(jì)中全浮式半軸桿部直徑的初步選取可按下式進(jìn)行 取 下面將進(jìn)行半軸的校核 半軸的扭轉(zhuǎn)應(yīng)力為 半軸的最大扭轉(zhuǎn)角為 式中半軸長(zhǎng)度 材料的剪切彈性模量 半軸橫截面的極慣性矩 則為 51 式中 見上式 41 下說(shuō)明 側(cè)驅(qū)動(dòng)輪帶輪轂及制動(dòng)器總成的質(zhì)量 驅(qū)動(dòng)殼的輪距 驅(qū)動(dòng)橋兩鋼板彈簧座間的距離取 圖 51 驅(qū)動(dòng)橋受力簡(jiǎn)圖 在水平面內(nèi)由牽引力產(chǎn)生的彎矩為 52 合成彎矩為 53 765498 2 通過(guò)不平路面垂直力最大時(shí) 汽車通過(guò)不平路面時(shí)橋殼受到最大垂直動(dòng)載荷此時(shí)危險(xiǎn)斷面在鋼板彈簧座附近其彎曲力矩為 54 1092026 式中 動(dòng)載荷系數(shù)轎車客車 175 貨車 25 越野車 30 見上式 51 下說(shuō)明 第 6 章 結(jié)論 汽車的底盤是汽車的主體底盤性能的好壞直接影響著汽車的性能而作為傳動(dòng)系末端的驅(qū)動(dòng)橋是汽車底盤的關(guān)鍵部件之一在對(duì) DD6990 中型客車驅(qū)動(dòng)橋的設(shè)計(jì)過(guò)程中主要實(shí)現(xiàn) 1 主減速器的設(shè)計(jì)確定了合適的傳動(dòng)比使用了單級(jí)代替原車的雙級(jí)主減速器采用先進(jìn)的雙曲面錐齒輪實(shí)現(xiàn)了降低轉(zhuǎn)速增加扭矩且改變扭矩的傳遞方向以適應(yīng)汽車的行駛方向參考文獻(xiàn) [1] 劉惟信．汽車車橋設(shè)計(jì)．北京清華大學(xué)出版社 2021 [2] 馮晉祥．專用汽車設(shè)計(jì)．北京人民交通出版社 2021 [3] 《汽車工程手冊(cè)》編輯委員會(huì)編汽車工程手冊(cè) 設(shè)計(jì)篇 北京人民交通出版社 2021 [4] 劉惟信．圓錐齒輪與雙面齒輪傳動(dòng)．北京人民交通出版社 1980 [5] 張玉亭．英漢雙向汽車詞典． 上海上海交通大學(xué)出版社 2021 [6] 黃韶炯欒志強(qiáng)汽車專業(yè)英語(yǔ)．北京人民交通出版社 2021 [7] 吳宗澤主編機(jī)械設(shè)計(jì)師手冊(cè) 北京機(jī)械工程出版社 2021 [8] 朱輝等．畫法幾何及工程制圖 第 5 版．上海上?？茖W(xué)技術(shù)出版社 2021 [9] John Fenton Handbook of Automotive Powertrain and Chassis Design London Professsoinal Engineering Publishing1998 [10] 鄭燕萍王瑜宋懷蘭 汽車驅(qū)動(dòng)橋 殼現(xiàn)代設(shè)計(jì)方法的探討 輕型汽車技術(shù) 2021 [11] 邱彥龍 國(guó)產(chǎn)汽車維修調(diào)整數(shù)據(jù)手冊(cè) [12] 王聰興馮茂林 現(xiàn)代設(shè)計(jì)方法在驅(qū)動(dòng)橋設(shè)計(jì)中的應(yīng)用 山東交通科技 2021 [13] 紀(jì)峻嶺 傳動(dòng)軸差速器驅(qū)動(dòng)橋車橋 化學(xué)工業(yè)出版社 2021 [14] 成大先機(jī)械設(shè)計(jì)手冊(cè) 化學(xué)工業(yè)出版社 2021 [15] 徐建平馬利濤精通 AutoCAD2021 中文版北京清華大學(xué)出版社 2021 致 謝 本畢業(yè)論文是在我的導(dǎo)師教授的親切關(guān)懷和悉心指導(dǎo)下完成的他嚴(yán)肅的科學(xué)態(tài)度嚴(yán)謹(jǐn)?shù)闹螌W(xué)精神精益求精的工作作風(fēng)深深地感染和激勵(lì)著我從課題 的選擇到項(xiàng)目的最終完成老師都始終給予我細(xì)心的指導(dǎo)和不懈的支持不僅在學(xué)業(yè)上給我以精心指導(dǎo)同時(shí)還在思想生活上給我以無(wú)微不至的關(guān)懷在此謹(jǐn)向老師致以誠(chéng)摯的謝意 在此我還要感在一起愉快的度過(guò)生活的正是由于你們的幫助和支持我才能克服一個(gè)一個(gè)的困難和疑惑直至本文的順利完成在論文即將完成之際我的心情無(wú)法平靜從開始進(jìn)入課題到論文的順利完成有多少可敬的師長(zhǎng)同學(xué)朋友給了我無(wú)言的幫助在這里請(qǐng)接受我誠(chéng)摯的謝意最后我還要感謝 The power developed inside the engine cylinder is ultimately aimed to turn the wheels so that the motor vehicle can move on the road The reciprocating motion of the piston turns a crankshaft rotating the flywheel through the connecting rod The circular motion of the crankshaft is now to be transmitted to the rear wheels It is transmitted through the clutch gearbox universal joints propeller shaft or drive shaft differential and axles extending to the wheels The application of engine power to the driving wheels through all these parts is called drivetrain The drivetrain is usually the same on all modern passenger cars and trucks but its arrangement may vary according to the method of drive and type of transmission units 1 Clutch Clutch is a device used in the transmission system of a motor vehicle to engage and disengage the engine to the transmission Thus the clutch is located between the engine and the transmission When the clutch is engaged the power flows from the engine to the rear wheels through the transmission system and the vehicle moves When the clutch is disengaged the power is not transmitted to the rear wheels and the vehicle stops while the engine is still running The clutch is disengaged when starting the engine when shifting the gears when stopping the vehicle and when idling the engine The clutch is engaged only when the vehicle is to move and is kept engaged when the vehicle is moving The clutch also permits the gradual taking up of the load When properly operated it prevents jerky motion of the vehicle and thus avoids putting undue stain on the remaining parts of the power transmission system The clutch works on the principles of friction When two friction surfaces are brought in contact with each other and pressed they are united due to the friction between them If now one is revolved the other will also revolve The friction between the two surface depends upon the area of the surfaces pressure applied upon them and coefficient of friction of the surface materials The two surfaces can be separated and brought into contact when required One surface is considered as driving member and the other as driven member The driving member is kept rotating When the driven member is brought in contact with the driving member it also starts rotating When the driven member is separated from the driving member it does not revolve This is the principle on which a clutch operates The friction surfaces of the clutch are so designed that the driven member slip on the driving member when the pressure is first applied As pressure increase the driven member is brought gradually to