汽車車輛類分動(dòng)箱的工作分析應(yīng)用外文文獻(xiàn)翻譯/中英文翻譯/外文翻譯

黑龍江工程學(xué)院本科生畢業(yè)設(shè)計(jì)   1 附   錄   所謂分動(dòng)箱，就是將發(fā)動(dòng)機(jī)的動(dòng)力進(jìn)行分配，分別輸出給前軸和后軸的裝置。從這個(gè)角度可以看出，分動(dòng)箱實(shí)際上是四驅(qū)車上的一個(gè)配件。隨著四驅(qū)技術(shù)的發(fā)展，分動(dòng)箱也一直進(jìn)行著改變，并逐漸形成了風(fēng)格迥異的分動(dòng)箱，匹配在不同訴求的四驅(qū)車上，它們的基本原理和功能也都是各不相同的。      最早的四驅(qū)技術(shù)，是基于提高車輛的通過性開發(fā)的，我們把它稱作越野四驅(qū)。這類車型的鼻祖威利斯吉普，就是二戰(zhàn)美軍為了加強(qiáng)前線步兵和指揮官作戰(zhàn)的機(jī)動(dòng)性開發(fā)出來的。它采用的分動(dòng)箱是最基本的分時(shí)四驅(qū)分動(dòng)箱，是一種純機(jī)械的裝置。這種結(jié)構(gòu)的分動(dòng)箱 ，在掛上 4 驅(qū)模式的時(shí)候，前后軸是剛性連接的，可以實(shí)現(xiàn)前后動(dòng)力 50 50 的分配，對(duì)于提高車輛的通過性非常有利。另外由于它的純機(jī)械結(jié)構(gòu)，可靠性很高，這對(duì)于經(jīng)常在缺少救援的荒野行駛的車型是至關(guān)重要的。即使到現(xiàn)在，仍然有大量的硬派越野車采用這種分動(dòng)箱，就是基于它這個(gè)特點(diǎn)。下面我們就來看看這種分動(dòng)箱的基本結(jié)構(gòu)和原理。      在此類車型的分動(dòng)箱擋把上，我們會(huì)看到 2H、 4H、 N、和 4L的切換擋位。當(dāng)掛 2H時(shí)，此類車型就是一臺(tái)后驅(qū)車，發(fā)動(dòng)機(jī)的動(dòng)力經(jīng)過變速箱以后，通過一根傳動(dòng)軸直接連接到后軸上。而分動(dòng)箱的作用，就是在變速箱 上，再引出一根輸出端，并通過靜音鏈條，將動(dòng)力傳遞到前軸的輸出軸。當(dāng)然，這并不是直接連接的，否則就無法切換 4 驅(qū)和 2 驅(qū)了。事實(shí)上，它是通過兩組齒輪實(shí)現(xiàn)分離和連接的，它的結(jié)構(gòu)和原理類似于變速箱的一軸和二軸。切換時(shí)，扳動(dòng)分動(dòng)箱的擋把，通過撥叉將動(dòng)力與前傳動(dòng)軸接通和斷開。與現(xiàn)在主流的帶同步器的變速箱不同，這個(gè)部位的切換是沒有同步器的，它需要轉(zhuǎn)速與輪速的完全匹配。這就是這種分動(dòng)箱的基本原理。      但實(shí)際情況并不會(huì)這么簡(jiǎn)單，為了提高通過性能，這類分動(dòng)箱還會(huì)有一個(gè)加力擋，也就是擋把上的 4L模式。在變速箱上，有一個(gè)齒比更 大的齒輪，當(dāng)掛上這個(gè)齒輪時(shí)，能提供比日常駕駛高很多的主傳動(dòng)比。我們發(fā)現(xiàn)，當(dāng)我們需要掛 4L時(shí)，必須經(jīng)過一個(gè) N 擋，此時(shí)變速箱會(huì)將動(dòng)力與每個(gè)傳動(dòng)軸分開，而掛上 4L時(shí)，將接通這個(gè)齒比更大的齒輪。這個(gè)切換的過程，也是沒有同步器的。      知道了這個(gè)原理，我們?cè)賮砜纯创祟惙謩?dòng)箱各個(gè)模式的操作特性。熟悉傳統(tǒng)越野車的車友都知道，這種分動(dòng)箱，在 2H和 4H之間切換時(shí)，不需要停車，一般可以在 80 公里 /小時(shí)的時(shí)速下自由切換。而切換到 2L時(shí)，則必須停車切換，否則根本掛不進(jìn)去，這是為什么呢？      無論是 2H模式還是 4H模式，動(dòng)力 一直是與后軸接通的，后輪的輪速與發(fā)動(dòng)機(jī)轉(zhuǎn)速完全匹配。而此時(shí)只要車輪沒有打滑，前輪與后輪的輪速是一樣的，因此在 2H與 4H之間切換時(shí)，發(fā)動(dòng)機(jī)轉(zhuǎn)速與前輸出軸的轉(zhuǎn)速是匹配的，即使沒有同步器，也完全可以進(jìn)行切換。因此在 2H模式和 4H模式間切換，完全可以在行車中進(jìn)行，不需要停車切換。但到了 4L模式的轉(zhuǎn)換時(shí)，情況就完全不同了。      從 4H切換到 4L模式，需要先將分動(dòng)箱切換為 N 擋，此時(shí)發(fā)動(dòng)機(jī)動(dòng)力與每個(gè)車輪都斷開，發(fā)動(dòng)機(jī)轉(zhuǎn)為怠速工況。此時(shí)如果掛 4L，車輪的輪速與發(fā)動(dòng)機(jī)的轉(zhuǎn)速會(huì)很難匹配，相當(dāng)于一臺(tái)不帶同步器的車行駛過程中想 掛一擋，這顯然是很難的。  黑龍江工程學(xué)院本科生畢業(yè)設(shè)計(jì)   2    這種分動(dòng)箱前后軸之間是沒有差速器的，因此在附著力高的公路上駕駛只能掛 2H， 4 驅(qū)模式僅僅是在沙石路面以及 OFF-ROAD 路段為提高通過性而設(shè)計(jì)。因此采用這種分動(dòng)箱的四驅(qū)車一般都是硬派越野車，它在 OFF-ROAD 路段很厲害，但在公路上則表現(xiàn)平平。      早期的分時(shí)四驅(qū)，是完全靠手動(dòng)切換的，發(fā)展到后來，出現(xiàn)了電動(dòng)切換的分時(shí)四驅(qū)，它的基本原理與手動(dòng)切換的分時(shí)四驅(qū)是一樣的，只不過所有的切換是通過電機(jī)來完成罷了。  1.全時(shí)四驅(qū)分動(dòng)箱      隨著四驅(qū)技術(shù)的發(fā)展，人們已經(jīng)不能僅僅滿足于 只能越野的四驅(qū)車。在公路上，采用四驅(qū)技術(shù)的車輛能提供更好的驅(qū)動(dòng)力和操控性能，因此全時(shí)四驅(qū)誕生了。      硬軸連接的四驅(qū)車不能實(shí)現(xiàn)公路四驅(qū)駕駛的最主要的原因，是它無法在公路上高速轉(zhuǎn)彎。因?yàn)樵谵D(zhuǎn)彎的時(shí)候，每個(gè)車輪所壓過的弧線長(zhǎng)度不一樣，這就意味著每個(gè)車輪的轉(zhuǎn)速都不能一樣。事實(shí)上，前輪的轉(zhuǎn)速是會(huì)高于后輪的，如果剛性地把發(fā)動(dòng)機(jī)的動(dòng)力通過傳動(dòng)軸分配給前后車輪的話，那么前后車輪的轉(zhuǎn)速就必須保持一致，這個(gè)矛盾將導(dǎo)致前后車輪在轉(zhuǎn)向的時(shí)候發(fā)生轉(zhuǎn)向干涉。這在附著力低的沙石路面可以通過輪胎與地面的滑動(dòng)摩擦解決，而在干燥路面則會(huì) 產(chǎn)生一個(gè)制動(dòng)力，讓車不能前進(jìn)，這就是我們常說的轉(zhuǎn)向制動(dòng)。      為了解決這個(gè)矛盾，工程師在分動(dòng)器中加入了一個(gè)差速器，這就是我們現(xiàn)在常說的中央差速器。這個(gè)差速器是開放式差速器，結(jié)構(gòu)與前后軸的差速器一樣，變速箱的輸出軸通過行星齒輪組將動(dòng)力分配給前后軸。根據(jù)開放式差速器的原理，它可以調(diào)整轉(zhuǎn)速差。這樣的結(jié)構(gòu)是不是就算是全時(shí)四驅(qū)了呢？早期全時(shí)四驅(qū)的雛形確實(shí)是這樣的，但我們會(huì)發(fā)現(xiàn)，這樣的四驅(qū)系統(tǒng)對(duì)于提高通過性來說毫無意義。我們知道，開放式差速器的功能是把發(fā)動(dòng)機(jī)動(dòng)力分配給受阻力小的車輪，如果一臺(tái)車上使用了三個(gè)開放式差速 器（前后軸各還有一個(gè)差速器）來調(diào)節(jié)轉(zhuǎn)速差的話，那么如果有一個(gè)車輪受阻力最小，動(dòng)力就會(huì) 100%地傳遞給這個(gè)車輪。顯然這種四驅(qū)是毫無意義的。      為了解決這個(gè)問題，不同的工程師采用了兩種不同的方案。      一種是差動(dòng)限制器。我們已經(jīng)知道，開放式差速器會(huì)將動(dòng)力傳遞給受阻力較小的車輪，那如果我們給這輛車人為施加一個(gè)阻力，動(dòng)力自然就能傳遞給沒有打滑（仍然有抓地力）的車輪了。它的基本結(jié)構(gòu)是一種類似于離合器的裝置，只不過它有很多組，我們把它稱作多片離合器式差動(dòng)限制器。在差速器殼體和兩個(gè)輸出軸各有一組鋼片，它們相互交 錯(cuò)，正常情況下互相之間是分離的。如果此時(shí)前輪打滑，它會(huì)將與前軸的離合器片壓合，從而將動(dòng)力更多地傳遞給后輪，后輪打滑的道理是一樣的。這種差動(dòng)限制器的種類有很多，有通過硅油實(shí)現(xiàn)的機(jī)械式（關(guān)于硅油的原理后文會(huì)詳述），也有通過電子控制離合器開合的電子式。在比較高檔的車型上，它的差動(dòng)限制器不僅解決車輪打滑的問題，還能起到主動(dòng)分配動(dòng)力的作用，甚至可以實(shí)現(xiàn)讓動(dòng)力從 0-100%之間在前后軸自由分配。      另一種則是中央差速鎖。它實(shí)際上相當(dāng)于在需要提高通過性的時(shí)候，可以將前后軸實(shí)現(xiàn)硬軸連接，動(dòng)力按照 50 50 分配給前后軸 。它的基本結(jié)構(gòu)是，在前后軸之間裝有摩擦鋼片，當(dāng)前輪或者后輪打滑時(shí)，機(jī)械裝置會(huì)通過電磁閥的控制將二者咬合實(shí)現(xiàn) 50 50 的固定動(dòng)力分配。還有一種全時(shí)四驅(qū)的分動(dòng)器結(jié)構(gòu)，那就是著名的奧迪 QUATTRO。它主要是通過蝸桿行星齒輪來實(shí)現(xiàn)的，結(jié)構(gòu)很復(fù)雜，這里就不再詳述了。它這種結(jié)構(gòu)能解決轉(zhuǎn)速差的問題，起到開放式差速器的作用，黑龍江工程學(xué)院本科生畢業(yè)設(shè)計(jì)   3 同時(shí)又能自動(dòng)將動(dòng)力分配給受阻力最大的問題，起到差動(dòng)限制器的作用。它可以實(shí)現(xiàn)動(dòng)力25% 75%之間的自由分配，而所有這些，都是通過它核心的托森差速器來實(shí)現(xiàn)的，更為神奇的是，這個(gè)托森差速器沒有用到任何電 磁裝置，是純機(jī)械式的。無論多先進(jìn)的電子設(shè)備都有響應(yīng)滯后的問題，因此與其他廠家的技術(shù)相比，純機(jī)械的 QUATTRO 在響應(yīng)速度方面是無人能及的。當(dāng)然它也有弊端 結(jié)構(gòu)復(fù)雜、造價(jià)高、動(dòng)力傳遞損失大是它無法跨越的硬傷。      與全時(shí)四驅(qū)匹配的還有電子差速制動(dòng)，主要是用來調(diào)整左右車輪的轉(zhuǎn)速差的，相當(dāng)于前差速鎖和后差速鎖。與差動(dòng)限制器相比，它的能量損耗較大，一般不用來實(shí)現(xiàn)前后車輪的動(dòng)力分配。    2.適時(shí)四驅(qū)的分動(dòng)箱      在此之后，有些廠家的工程師們發(fā)現(xiàn)，并不是所有路況都需要四驅(qū)系統(tǒng)的，例如在正常公路巡航駕駛的時(shí)候， 只通過兩輪驅(qū)動(dòng)就完全能滿足所有的駕駛需求了。此時(shí)如果仍采用全時(shí)四驅(qū)，既不經(jīng)濟(jì)，也沒有必要。因此，在多數(shù)情況下只是兩輪驅(qū)動(dòng)，而在必要的時(shí)候自動(dòng)變?yōu)樗尿?qū)的適時(shí)四驅(qū)誕生了。      適時(shí)四驅(qū)也有兩種解決方案，一種是以本田 CR-V 為代表的通過粘性連軸節(jié)實(shí)現(xiàn)；一種是以上一代的 4-MATIC 為代表的通過多片離合器實(shí)現(xiàn)。它們雖然都能達(dá)到正常時(shí)兩輪驅(qū)動(dòng)，驅(qū)動(dòng)輪打滑時(shí)自動(dòng)接通四驅(qū)的效果，但結(jié)構(gòu)和功能還是有區(qū)別的。      CR-V為代表的這類適時(shí)四驅(qū)分動(dòng)箱結(jié)構(gòu)最為簡(jiǎn)單，它是基于前橫置發(fā)動(dòng)機(jī)前輪驅(qū)動(dòng)的技術(shù)平臺(tái)，在兩驅(qū)方面，與之 前的轎車平臺(tái)完全一樣。在此基礎(chǔ)上，工程師在變速箱上引出一根通往后軸的輸出軸，與后橋差速器之間，采用粘性連軸節(jié)連接。在這個(gè)連軸節(jié)里充滿了硅油，它的特點(diǎn)是溫度升高以后粘度也會(huì)迅速升高。在連軸節(jié)的輸出端和輸入端，都裝有一個(gè)葉片，就類似于液力變矩器的結(jié)構(gòu)。當(dāng)正常行駛前輪沒有打滑的時(shí)候，前后輪之間是沒有輪速差的，這個(gè)粘性連軸節(jié)里的兩根軸相互之間也就沒有轉(zhuǎn)速差。此時(shí)動(dòng)力是不會(huì)傳遞給后軸的。當(dāng)前輪打滑的時(shí)候，前輪的轉(zhuǎn)速將大于后輪，此時(shí)粘性連軸節(jié)里的輸入端轉(zhuǎn)速會(huì)超過輸出端，就如同液力變矩器一般，能夠?qū)?dòng)力傳遞給后軸。不僅如 此，由于轉(zhuǎn)速差能導(dǎo)致硅油升溫而變粘稠，從而進(jìn)一步增加對(duì)動(dòng)力的傳遞，驅(qū)動(dòng)后輪。通過這個(gè)結(jié)構(gòu)我們會(huì)發(fā)現(xiàn)，它的響應(yīng)速度是比較慢的，而且動(dòng)力傳遞也很有限，很難將 50%的動(dòng)力分配給后軸。但它的結(jié)構(gòu)簡(jiǎn)單、成本低，對(duì)于以城市道路駕駛的 SUV來說，基本能滿足其需求。      上一代 4-MATIC 為代表的適時(shí)四驅(qū)分動(dòng)箱，結(jié)構(gòu)比粘性連軸節(jié)的適時(shí)四驅(qū)要復(fù)雜一些，與前面所說的中央差速鎖有些類似，它是通過電磁離合器來實(shí)現(xiàn)四驅(qū)接通的。它同樣是基于兩驅(qū)平臺(tái)開發(fā)出來的四驅(qū)系統(tǒng)，在變速箱的一端通過盆型齒輪引出一根傳動(dòng)軸將動(dòng)力傳遞給前輪，之間 靠多片離合器連接。它的接通與斷開的原理與之前說的中央差速鎖的原理類似，這里就不贅述了。它的好處是結(jié)構(gòu)比全時(shí)四驅(qū)簡(jiǎn)單，響應(yīng)速度和動(dòng)力分配比粘性連軸節(jié)要好。      隨著結(jié)構(gòu)的四驅(qū)技術(shù)的進(jìn)一步發(fā)展，現(xiàn)在有些車型已經(jīng)可以實(shí)現(xiàn)動(dòng)力的自由分配了，很多的官方宣傳把這種四驅(qū)也稱作全時(shí)四驅(qū)，事實(shí)上是不準(zhǔn)確的。與具備中央差速鎖的真正全時(shí)四驅(qū)相比，這種靠多片離合器實(shí)現(xiàn)動(dòng)力分配的所謂全時(shí)四驅(qū)，最多只能將動(dòng)力的 50%分配給從動(dòng)輪，而且在轉(zhuǎn)彎時(shí)的動(dòng)力分配等方面，都無法達(dá)到真正全時(shí)四驅(qū)的水平。從本質(zhì)上說，這類四驅(qū)仍然只能稱作適時(shí)四驅(qū)， 例如大眾 的 4-Motion。 3.超選四驅(qū)分動(dòng)箱  黑龍江工程學(xué)院本科生畢業(yè)設(shè)計(jì)   4 這個(gè)稱呼是三菱的，一直以來也被看做是三菱的看家技術(shù)。      從分動(dòng)箱的擋把看，它更像是傳統(tǒng)的分時(shí)四驅(qū)系統(tǒng)，所不同的是，它是具備中央差速器的。當(dāng)掛上 4H的時(shí)候，不僅能在沙石路面上高速行駛，也能在普通公路上實(shí)現(xiàn)公路四驅(qū)的功能。而它提供的 4HLC 和 4LLC 選項(xiàng)，則是鎖上了中央差速鎖的四驅(qū)模式，在這個(gè)時(shí)候，它與分時(shí)四驅(qū)的4H和 4L的功能是一樣的。      之所以三菱稱之為超選，實(shí)際上是因?yàn)樗人械乃尿?qū)系統(tǒng)可選擇的范圍都要多。一般的全時(shí)四驅(qū)車，只能選擇四驅(qū)行駛，在不 需要四驅(qū)的時(shí)候，這樣的方式顯然不經(jīng)濟(jì)；而適時(shí)四驅(qū)雖然可以實(shí)現(xiàn)兩驅(qū)，但在四驅(qū)的時(shí)候無法達(dá)到真正的全時(shí)四驅(qū)的性能；分時(shí)四驅(qū)就不用說了，它完全不能實(shí)現(xiàn)公路四驅(qū)駕駛。而所有這些，超選四驅(qū)都能選擇 想經(jīng)濟(jì)性好，就掛上 2H，想公路全時(shí)四驅(qū)就掛上 4H，想達(dá)到與傳統(tǒng)分時(shí)四驅(qū)一樣的通過性，就掛上 4HLC 或者 4LLC。   The so-called transfer case, is the power of the engine for the distribution, output to front axle and rear axle respectively of the device. From this point of view can see, transfer case is actually the raider buggies a accessories. Along with the raider buggies technology develop ment, th黑龍江工程學(xué)院本科生畢業(yè)設(shè)計(jì)   5 e transfer case also has been the change, and gradually form the style different transfer case, matching the raider is in different appeal, their basic principle and function are also different.  The first raider technology, is based on the improve vehicle through sexual development, we called it the cross-country raider buggies. This kind of car is the ancestor of the second world war, American troops Willis jeep in order to strengthen the front line infantry and commander of the development of mobility out of combat. It used Transfer case is the most basic points raider Transfer case, is a pure mechanical device.The structure of the Transfer case, hang up the 4 flooding patterns, rear axle is before the rigid connection, may realize the power 50: the before and after 50 distribution, to improve the vehicles through sexual very favorable. Plus, because it purely mechanical structure, high reliability, this to often lack the wilderness in rescue vehicles driving is very important. Even now, there are still a lot of hard sent by theTransfer case suv, is based on the characteristics of it. Let's take a look at this Transfer case basic principle and structure. In this kind of car Transfer case on the block, we will see 2H,4H,N and 4L switching gears. When hang 2H, such models is a whip, the power of the engine driving after gearbox, through a shaft after root connected directly to the rear axle. And Transfer case role, which is in the gearbox, and then lead to an output terminal, and through the mute chain, will power transfer to the front axle output shaft. Of course, this is not to direct connection, it will not switch 4 flooding and 2 flooding. In fact, it is through the two groups of gear separated and connection of the structure and principle, it is similar to the one axis, and two transmission shaft. When switching Transfer case throw of the block, through the fork will power and transmission through and disconnect before. And now the mainstream with synchronizer gearbox, the part of the different switching is no synchronizer, it needs the wheel speed and the match. This is the Transfer case basic principle. But the truth is not so simple, in order to improve the performance of this kind of Transfer case through, there will still be one block, also is the strength of the block on 4L model. In the gearbox, more than the gear tooth, when hung up the gear, can provide a much higher than daily driving the main transmission. We found that when we need to hang 4L, must go through a N block, at this time will power and each transmission shaft separated, and hang up 4L, will be through to this tooth more than the gear. The switch of the process, is also no synchronizer.  Know the principle, we take a look at this Transfer case each mode of operation characteristics. Familiar with traditional suvs, having know this Transfer case, in 2H and 4H, we do not need to switch between parking, can generally in the 80 km/hour per hour free switch. And switch to 2L, it must stop switch, or fundamental hang in, is this why?  Whether 2H mode or 4H mode, the power is always connected with rear-axle, the rear whe黑龍江工程學(xué)院本科生畢業(yè)設(shè)計(jì)   6 els wheel and engine speed completely match. But at this time as long as no sliding, front wheel and rear wheel speed is same, so in 2H and 4H switch between, engine speed and output shaft speed is before the match, even without synchronizer, also can switch. So in 2H mode and 4H mode, can switch between the onboard, need not stop switch. But in the 4L mode switch, it was completely different.    From 4H switch to 4L model, need to add Transfer case switch for N block, this time of engine power and each wheel are disconnected, engine to idling process. If this time the wheels of L, hang 4 wheel and the speed of the engine can be hard to match, equivalent to a without synchronizer driving process want to hang a block, this is clearly a very difficult.  This Transfer case between front axle is not between the differential, therefore in the high adhesion of the ROAD can only hang 2H, 4 flooding mode is only in the gravel ROAD and OFF ROAD sections to improve-through sexual and design. So the method of this Transfer case buggies are generally hard-line rovers, it in the OFF-ROAD sections it bad, but in the highway is average performance.  The early time, is totally by manual raider switch, later, there was electric switch points raider buggies, it the basic principles and manual switching points raider is same, but all of the switch is through the motor to complete it.  1.Transfer case full-time raider buggies  With the development of the technology of raider buggies, people are not satisfied with just four drove cross-country only. In the highway, the raider buggies technology vehicles can offer a better driving force and control performance, so full-time raider was born.  Hard shaft link of raider buggies can't achieve highway raider driving the main reason, is it not in freeway turn. Because in when turning, each wheel crushes the arc length different, this means that each of the wheel speed are not the same. In fact, the speed of the front wheel is will be higher than the rear wheels, if the rigid to the power of the engine through the drive shaft before and after assigned to the wheel, then the before and after the wheel speed must be consistent, the contradiction between before and after the steering wheel will lead to occur to interfere. The adhesion of sand of pavement in low by the sliding friction tires and the ground, and in dry pavement solution will produce a braking, let the car won't go forward, this is we often say to brake.      In order to resolve the contradiction, the engineer in thansfer joined the a differential, this is we are now often say the central differential. The differential is open differentials, structure and the differential between front axle, as well as the output shaft transmission through planetary gear set will power distribution to rear axle before. According to the principle of differential open mode, it can adjust the speed diffe黑龍江工程學(xué)院本科生畢業(yè)設(shè)計(jì)   7 rence. This structure is even full-time raider? The prototype of the early full-time raider is really such, but we will find, the raider buggies to improve the system through sexual makes no sense. We know, open mode is the function of differential the engine power distribution to the small resistance wheels, if a car use of three open differential (between front axle and a differential) each to adjust the speed difference of words, so if there is a wheel has the least resistance, by motivation to transfer to the wheels by 100%. Obviously this raider is pointless.  In order to solve this problem, different engineer USES two different project. One is the differential limit. We already know, open mode will be passed to the power differential resistance smaller wheels, by that if we give the car a resistance on human nature, the power can be passed to the no sliding (there are still grip the wheels of). Its basic structure is a kind of similar to the device, but it clutch many groups, we called it the multi-gear clutch type differential limit device. In the differential shell and two output shaft each have a set of pieces of steel, their mutual crisscross, normally between each other is separated. If the front wheels skid, it will front axle and the pressure and the clutch disc, which will power transfer to the rear wheels more, rear wheel slippage, the truth is the same. This is the type of differential limit has a lot of, have through the silicone oil of the realization of the mechanical (about the principle of silicone oil after described the) and through the electronic control of electronic electrical switching of the clutch. In the more upscale cars, it is not only the differential limit solution to the wheel slippage problem, still can have the initiative of the power distribution function, can even realize the power from 0 to 100% in the first free distribution between rear axles. Another is the central differential lock. It actually is equivalent to need to improve through the sex, can be hard to realize between front axle shaft link, power, according to 50 50 assigned to rear axle before. Its basic structure is in between, between front axle with friction, the current round of steel or rear wheels skid, mechanical device will through the electromagnetic valve control of both a bite to realize the fixed, 50 50 power distribution. There is a full-time raider buggies, that is the thansfer structure of the famous audi QUATTRO. It is mainly through the worm planetary gear to achieve, structure is complex, here no longer expatiatory. This structure can solve the problem of poor speed, plays the role of open differential, at the same time can automatically will power distribution to the resistance of the biggest problems that have the function of the differential limit. It can achieve 25%-75% of power between free distribution, and all this is through the core of it, to realize the differential's, more magical is, the "spider's without the use of any el黑龍江工程學(xué)院本科生畢業(yè)設(shè)計(jì)   8 ectromagnetic device that is pure mechanical. No matter how advanced electronic equipment are lags in response problem so and other manufacturers of technical, compared the purely mechanical QUATTRO in velocity response is no one can and. Of course it has drawbacks-structure is complex, cost is high, power transmission loss is it could not cross the shortcomings.  And full-time raider matching and electronic differential braking, is mainly used to adjust or so the wheel speed difference, before the lock and differential equivalent after differential lock. And the differential limit, compared the energy loss is bigger, generally do not to realize the wheels of before and after power distribution.  2.The raider Transfer case timely  After that, some manufacturer's engineers found that not all need raider system of the road, for example in the normal cruising highway driving, only through the two wheel drive was completely can meet all driving demand. If this time still use a full-time raider buggies, neither economy, also don't have to. Therefore, in most cases only two wheel drive, and when necessary to be automatic into the raider buggies timely raider was born.  Timely raider buggies also have two solutions, one with Honda CR-V, as a representative of the cohesive shaft quarter even through implementation； A is above generation of 4 MATIC-as a representative of the through the multi-gear clutch realized. Although they can achieve normal when two wheel drive, the drive wheels skid automatically through the effect of raider buggies, but yet there are differences between the structure and function.  CR-V as a representative of this kind of timely raider Transfer case structure most simple, it is based on the horizontal buy before the engine front wheel drive technology platform, in two aspects, and flooding the car platform is exactly the same as before. On this basis, the engineer in the gearbox brings the root to rear axle output shaft, and driving axle differential between, use the cohesive shaft quarter even connection. Even in the shaft section is filled with silicone oil, it is characteristic of temperature rise will also rise after viscosity. Even the axis of the festival in output and input, are equipped with a blade, similar to the hydraulic torque converter structure. When moving the nose wheel is not skid, there is no round between the control speed difference, the cohesive shaft in the quarter even two shaft between each other is no speed difference. At this time is not passed to power the rear axle. The current round of sliding, the speed of the front wheel will be greater than the rear wheels, even at this time of day cohesive shaft input speed will more than the output, as hydraulic torque converter general, able to power transfer to rear axle. Not o黑龍江工程學(xué)院本科生畢業(yè)設(shè)計(jì)   9 nly that, because the rotation speed difference can cause heating up and become viscous silicon oil, so as to further increase the power of transmission, rear wheel drive.     Through this structure, we will find that the response speed, it is more slowly, and power transfer is limited, and it is difficult to will be 50% of power distribution to rear axle. But its simple structure, low cost, for city road driving to the SUV, it can meet the basic needs.  A generation 4 MATIC-as a representative of the timely Transfer case raider buggies, structure than even shaft section of the sticky timely raider is more complicated, and the above the central differential lock some similar, it is through the electromagnetic clutch to realize the raider buggies. It is also based on two flooding platform is developed, the raider buggies system in one end of the transmission in the basin type gear shaft brings the root will power transfer to front wheel, by connection between multi-gear clutch. It's connected to the broken and principle and said before the central differential lock principle similar, there is no redundancy. Its advantage is than full-time raider simple structure, response speed and power distribution cohesive shaft is better than even section.  Along with the