【文章內(nèi)容簡介】 ssion gear ratio to determins .......................... 17 The minimum transmission gear transmission ratio.................... 17 The other block transmission of the transmission ratio .............. 18 The determination of center distane......................................................... 19 Transmission dimensions of primaries .................................................... 19 Transmission gear selection of parameters.............................................. 20 Modulus.......................................................................................... 20 Tooth pressure angle and helix angle ........................................... 20 Tooth width .................................................................................... 21 Tooth top of the high coefficient .................................................. 22 Transmission of each block the distribution of the gear teeth................ 22 Determine the number of teeth of first gear................................. 22 Corrected to the center distance.................................................... 24 To determine the constant mesh gear teeth .................................. 24 To determine the gear number of teeth......................................... 26 Chapter summary ...................................................................................... 29 Chapter 4 The design of the tranmision gear.................................................. 30 The geometry of the transmission gear.................................................... 30 Calculate the transmission of torque and rotational speed of each axis 31 Gear strength calculations and material selection................................... 32 The caues and forms of gear damage ........................................... 32 Material selection of the gear........................................................ 33 Strength calculation of gears ......................................................... 34 Chapter summary ..................................................................................... 46 Chapter 5 Transmission shaft and bearing design calculations ................... 47 Primary transmission axis of the shaft diameter and axial length ......... 47 The structural design of the shaft............................................................. 48 The strength of the transmission axis ...................................................... 49 Gear and the shaft of the force calculation .................................. 49 Axis intensity calculate ................................................................. 50 VIII Shaft stiffness calculate................................................................. 55 Selection and verification of the transmission bearing........................... 59 Selection and verification of the first shaft bearing .................... 59 Selection and verification of the second shaft bearing................ 60 Selection and verification of the intermediate shaft bearings ..... 61 Chapter summary ...................................................................................... 61 Chapter 6 Synchronizer and the selection of the design of the control me chanism ........................................................................................ 62 Selection with the design of synchronizer............................................... 62 Lock ring synchronizer ................................................................. 63 Latch synchronizer ........................................................................ 64 Lock ring synchronizer determine the size of.............................. 65 The main parameters of the synchronizer .................................... 66 Design uses transmission control mechanism ......................................... 68 Classification of transmission control agencies........................... 68 Analysis of transmission monly used control mechanism ... 70 The design of the transmission box ......................................................... 71 Chapter summary ...................................................................................... 72 Conclusion ............................................................................................................... 73 Thanks...................................................................................................................... 74 References................................................................................................................ 75 1 第 1 章 緒 論 汽車變速器概述 變速器用于轉(zhuǎn)變發(fā)動機曲軸的轉(zhuǎn)矩和轉(zhuǎn)速，以適應汽車在起步、加速、行駛以及克服各種道路障礙等不同行駛條件下，對驅(qū)動車輪牽引力及車速不同要求的需要。用變速器轉(zhuǎn)變發(fā)動機轉(zhuǎn)矩、轉(zhuǎn)速的必要性在于內(nèi)燃機轉(zhuǎn)矩 轉(zhuǎn)速變化特性的特點是具有相對小的對外部載荷改變的適應性 [1]。 變速器能使汽車以非常低的穩(wěn)定車速行駛，而這種低的車速只靠內(nèi)燃機的最低穩(wěn)定車速是難以達到的。變速器的倒擋使汽車能倒退行駛；其空擋使汽車在啟動發(fā)動機、停車和滑行時能長時間將發(fā)動機和傳動系分離。 變速器按其傳動比的 改變方式可分為有級、無級和綜合式的。有級變速器按其前進擋的擋位數(shù)分為三、四、五擋和多擋的；而按其軸中心線的位置又可分為固定軸線式、旋轉(zhuǎn)軸線式和綜合式的。固定軸式變速器又分為兩軸式、三軸式和多軸式的。變速器按其操縱方式又可分為自動式、半自動式、預選式、指令式、直接操縱式和遠距離操縱式 [2]。 變速器的結(jié)構(gòu)對汽車的動力性、經(jīng)濟性、操縱的可靠性與輕便性、傳動的平穩(wěn)性與效率等都有直接影響。變速器與主減速器及發(fā)動機的參數(shù)做優(yōu)化匹配，可得到良好的動力性與經(jīng)濟性；采用自鎖及互鎖裝置，倒擋安全裝置，對接合齒采取倒錐齒側(cè)措施 以及其他結(jié)構(gòu)措施，可使操縱可靠，不跳擋、亂擋、自動脫擋和誤掛倒擋；采用同步器可使換擋輕便，無沖擊及噪聲；采用高齒、修形及參數(shù)優(yōu)化等措施可使齒輪傳動平穩(wěn)、噪聲低，降低噪聲水平已成為提高變速器質(zhì)量和設計、工藝水平的關鍵。隨著汽車技術的發(fā)展，增力式同步器，雙、中間軸變速器，后置常嚙合傳動齒輪、短第二軸的變速器，各種自動、半自動以及電子控制的自動換擋機構(gòu)等新結(jié)構(gòu)也相繼問世。 變速器多采用飛濺潤滑，重型汽車有時強制潤滑第一、二軸軸承等。 變速器都裝有單向的通氣閥以防殼內(nèi)空氣熱脹而漏油及潤滑油氧化。殼底放油塞多放置磁鐵 以吸附油內(nèi)鐵屑。 2 汽車變速器設計的目的和意義 現(xiàn)代汽車上廣泛采用內(nèi)燃機作為動力源，其轉(zhuǎn)矩和轉(zhuǎn)速的變化范圍很小，而復雜的使用條件要求汽車的驅(qū)動力和車速能在相當大的范圍內(nèi)變化。為解決這一矛盾，在傳動系統(tǒng)中設置了變速器，用來改變傳動比，擴大驅(qū)動輪轉(zhuǎn)矩和轉(zhuǎn)速的變化范圍，以適應經(jīng)常變化的行駛條件，如起步、加速、上坡等，同時使發(fā)動機在最有利的工況范圍下工作；在發(fā)動機旋轉(zhuǎn)方向不變的前提下，使汽車能倒退行駛；利用空 擋 ，中斷動力傳遞，以使發(fā)動機能夠起動、怠速，并便于變速器換 擋 或進行動力輸出。變速器設計的目的就是為了滿足上述的要求，使汽車在特定的工況下穩(wěn)定的工作。 變速器除了要能滿足一定的使用要求外，還要保證使其和汽車能有很好的匹配性，可以提高汽車的動力性和經(jīng)濟性，保證發(fā)動機在有利的工況范圍內(nèi)工作提高汽車的