基于ADAMS的汽車主減速器設(shè)計
基于ADAMS的汽車主減速器設(shè)計,基于,ADAMS,汽車,減速器,設(shè)計
密 級
分類號
編 號
成 績
本科生畢業(yè)設(shè)計 (論文)
外 文 翻 譯
原 文 標 題
Truck Main Reduction Gear
譯 文 標 題
貨車主減速器
作者所在系別
機械工程系
作者所在專業(yè)
車輛工程
作者所在班級
B13141
作 者 姓 名
王杰
作 者 學 號
201322190
指導教師姓名
臧繼嵩
指導教師職稱
完 成 時 間
2017
年
3
月
30
北華航天工業(yè)學院教務(wù)處制
譯文標題
貨車主減速器
原文標題
Truck Main Reduction Gear
作 者
Martin Balvín
譯 名
國 籍
原文出處
Core網(wǎng)
貨車主減速器
在能源競爭激烈的二十世紀七十年代初,汽車業(yè)不得不將注意力越來越多地定格在改進產(chǎn)品的質(zhì)量上,但仍然維持其盡可能低的價格。在此之前,吉凱恩車橋有限公司占據(jù)著最佳經(jīng)濟規(guī)模的優(yōu)勢,他們是最具競爭力的公司,在價格允許范圍內(nèi)生產(chǎn)極具競爭力的不同類型車軸,使所有客戶的需求可以得到滿足,所有類型的車軸都可以制造。但由于汽車制造商并沒有經(jīng)歷過這樣一個非常注重燃油經(jīng)濟性的時期,因此,對重量輕的要求,這些標準車軸似乎可滿足所有條件,滿足各種各樣的應(yīng)用。現(xiàn)在汽車制造商需要車軸設(shè)計和開發(fā)的具體應(yīng)用。軸設(shè)計正變得越來越專業(yè)化,在性能的可靠性方面,客戶越來越多地提高自己的期望。出
于這個原因,他們在找一個能提供各種車輛軸的公司。
然而自二十世紀七十年代以來,在幾乎所有其他汽車行業(yè)供應(yīng)商的技術(shù)里, GKN從根本上改變了它的原有的方法,從而來以適應(yīng)當前的環(huán)境,滿足不同汽車的需求,他們在二十世紀八十年代和九十年代的生產(chǎn)目的是提供完整的輪軸安裝,其中包括,剎車、所有的設(shè)計和整合、具體的汽車設(shè)計,以及為專業(yè)市場特別設(shè)計的各種剎車、輪軸以及整合,甚至包括具體的汽車設(shè)計。
現(xiàn)在的重點是選擇合理化的材料,方法和內(nèi)容途徑??偟母母锸潜匾?,對于復雜性很大的現(xiàn)代化汽車,需要考慮總體的效率,緊湊性,汽車的質(zhì)量要輕,考慮汽車的可靠性,汽車的耐用性,汽車的完善性以及汽車的免維護運行的能力。在另一個方面,GKN提供的車軸是擴大了供應(yīng)的部件和組件,如限滑差速器,球關(guān)節(jié),齒輪和某些類型的懸掛架。
? 對于越野車,某些車輛設(shè)計公司花費了相當多的精力在較低齒輪但高扭矩的齒輪設(shè)計上。在大多數(shù)情況下,多變的地形可能使這樣的汽車輪胎發(fā)生打滑等現(xiàn)象。例如,在相當堅硬的沙質(zhì)路面上,它可能允許輪胎咬進去,輪胎可以陷入地面內(nèi),從而使扭轉(zhuǎn)疲勞顯著大于在平穩(wěn)的道路行駛,也就是說增大了輪胎的抓地能力。雖然在很大程度上這種抓地能力,這種與地面交合的能力取決于汽車的速度,但汽車速度過大的話,汽車的縱向和橫向打滑發(fā)生的可能性也會將更加的嚴重。沖擊負荷也會影響剎車和加速扭矩,車速過大造成的剎車不平穩(wěn),速度過大同時會需要更大的發(fā)動機轉(zhuǎn)矩這都會增加發(fā)動機的沖擊負荷,這種沖擊負荷影響是取決于速度的。
準雙曲面齒輪傳動是錐齒輪傳動中的普遍形式,而螺旋錐齒輪傳動中的螺旋錐齒輪是準雙曲線齒輪的一種特殊情況。他們的優(yōu)點是齒輪的具體比例較大,齒輪體積較大,齒輪的齒與齒之間的嚙合區(qū)域也較大,這種錐齒輪傳動所具有的優(yōu)點就是低噪音,這種錐齒輪他們從本質(zhì)上是強度更大,硬度更大,齒輪的運轉(zhuǎn)更持久齒輪的使用也更耐用。
汽車主減速器的作用是用來降低傳動軸傳來的轉(zhuǎn)速而增大旋轉(zhuǎn)扭矩,并將扭矩改變傳動方向,經(jīng)差速器傳給半軸,發(fā)動機傳來的轉(zhuǎn)速一般都比較大,通過減速器,因傳動比的存在可以降低差速器的轉(zhuǎn)速同時增大齒輪的轉(zhuǎn)矩。汽車主減速器的結(jié)構(gòu)和形式主要是根據(jù)齒輪的類型、減速器形式不同而不同,不同的結(jié)構(gòu)形式不同的齒輪類型所對應(yīng)的汽車減速器不同。汽車主減速器的齒輪主要有螺旋錐齒輪、雙曲面齒輪、圓柱齒輪和蝸輪蝸桿等形式。
雙級主減速器與單級主減速器相比,在保證離地間隙相同時可得到更大的傳動比,傳動比i0一般為7~12。但是雙擊主減速器尺寸、質(zhì)量均較大,這種減速器的成本也較高。這種雙級主減速器主要應(yīng)用于中型、重型貨車、越野車和大客車上。
整體式雙級主減速器有多種結(jié)構(gòu)方案:第一種方案是,第一級傳動齒輪為錐齒輪,第二級傳動齒輪為圓柱齒輪;第二種方案是,第一級傳動齒輪為錐齒輪,第二級傳動齒輪為行星齒輪;第三種方案是,第一級傳動齒輪為行星齒輪,第二級傳動齒輪為錐齒輪;第四種方案是,第一級傳動齒輪為圓柱齒輪,第二級傳動齒輪為錐齒輪。
對于第一級傳動齒輪為錐齒輪、第二級傳動齒輪為圓柱齒輪的雙級主減速器,又有不同的布置方案,具體可有縱向水平布置方案、斜向布置和垂向布置三種布置方案。
縱向水平布置可以使總成的垂向輪廓尺寸減小,使汽車減速器的整體尺寸在水平方向上減小,從而降低汽車的質(zhì)心高度,但與此同時使縱向尺寸增加使汽車變得更寬,但這種缺點在不同的汽車上使用可以變劣勢為優(yōu)勢,當用在長軸距汽車上時可適當減小傳動軸的長度,但不利于短軸距汽車的總布置,如果布置在短軸距汽車上會使傳動軸過于短,導致萬向傳動軸的夾角加大。垂向布置的減速器可以使驅(qū)動橋的縱向尺寸減小,與此同時可減小萬向傳動軸的夾角,但由于這種垂向布置的主減速器殼固定在橋殼的上方,這種布置形式不僅使垂向輪廓尺寸增大,而且降低了橋殼的剛度,這種垂向布置形式不利于齒輪工作。但是這種布置形式也有他的優(yōu)勢,雖然這種布置降低了橋殼的剛度不利于齒輪工作,但是可便于貫通式驅(qū)動橋的布置。而斜向布置對傳動軸布置和提高橋殼剛度都有利,可以說是具有了垂直布置形式和縱向布置形式的優(yōu)點。
在具有錐齒輪和圓柱齒輪的雙級主減速器中,需要分配兩級傳動比的比值各為多少,在分配傳動比時,我們根據(jù)以往的經(jīng)驗和設(shè)計數(shù)據(jù)顯示,讓圓柱齒輪副和錐齒輪副傳動比的比值一般應(yīng)為1.4~2.0,而且錐齒輪副傳動比一般為1.7~3.3,這樣分配傳動比的優(yōu)點是可減小錐齒輪嚙合時的軸向載荷,與此同時可使作用在從動錐齒輪及圓柱齒輪上的載荷減小,同時可使主動錐齒輪的齒數(shù)適當增多,增加了主動錐齒輪的齒數(shù)使其支承軸頸的尺寸適當加大,以改善其支承剛度,提高齒輪間嚙合的平穩(wěn)性和工作可靠性。
現(xiàn)代齒輪設(shè)計中,齒輪潤滑油的選擇是至關(guān)重要的。汽車運行在高速公路上,車橋油溫可以最終上升到很高的溫度,有時潤滑油的油溫甚至會高于130℃ ,所以在設(shè)計中保持車橋外殼的通風良好也是很重要的。這種良好的通風性可以通過兩個軸承攜帶的小齒輪來達到改善的目的。因此,齒輪的形狀和齒輪尺寸之間的間隙,套管等的設(shè)計可能都是至關(guān)重要的,在減速器設(shè)計時,需要有足夠的排水能力,水冷卻的水道,油冷的油道設(shè)計都至關(guān)重要。在設(shè)計中必須提供的潤滑油的流向,油液通過渠道流入小齒輪軸承座,再回到套管。
在齒輪的軸承選擇中,圓錐滾子軸承普遍應(yīng)用在齒輪的設(shè)計中。因為圓錐滾子軸承他們有較大的承載能力,具有較為良好的通過穩(wěn)定性、和較為準確的定位。法蘭密封的齒輪對于抗高溫和相對較高的速度是至關(guān)重要的。
在齒輪設(shè)計中錐齒輪齒面過寬并不能增大齒輪的強度和壽命,反而會導致因錐齒輪輪齒小端齒溝變窄引起的切削刀頭的情況,與此同時齒面過寬還會導致切削刀頭頂面寬過窄及刀尖圓角過小。這樣,不但減小了齒根圓半徑,加大了應(yīng)力集中,從而還降低了刀具的使用壽命。此外,在安裝時由于安裝位置偏差或著由于制造、熱處理變形等原因的存在,各種加工制造誤差也有可能累積,導致加工誤差大,使齒輪工作時載荷集中于輪齒小端,會引起輪齒小端由于應(yīng)力集中,磨損嚴重等情況,使其過早損壞和疲勞損傷。另外,齒面過寬也會引起裝配空間的減小。但是也不是說齒面越小越好,齒面若是過窄,輪齒表面的耐磨性會降低,從而使齒輪的耐磨性下降,強度不足等情況的,從而影響減速器的正常工作。
為改善新齒輪的磨合能力,防止其在運行初期出現(xiàn)早期的磨損、擦傷、膠合或咬死等情況,錐齒輪設(shè)計時在選擇加工處理時應(yīng)特別注意,在熱處理及精加工后,要作厚度為0.005~0.020mm的磷化處理或鍍銅、鍍錫處理。對減速器錐齒面進行應(yīng)力噴丸處理,這種處理方式可提高齒輪25%的使用壽命。對于在運行過程中滑動速度高的齒輪,可進行滲硫處理以提高耐磨性。滲硫后齒輪間的摩擦因數(shù)可顯著降低,即使齒輪的潤滑條件變得較差,也能防止齒面擦傷、咬死和膠合的情況。
Truck Main Reduction Gear
In the highly competitive period following the energy crisis of the early 1970's, the automotive industry had to shift attention increasingly towards improvement of the quality of the product, yet still keeping its prices as low as possible. Prior to that GKN Axles Ltd, to take optimum advantage of economies of scale, had been producing at highly competitive prices a standard range of axles of different types and sizes, from which all customers' needs could be satisfied. Because vehicle manufacturers had not hitherto had to place such a great emphasis on fuel economy, and therefore on light weight, these standard axles could cater reliably for all conditions likely to be met in a wide variety of applications. Now vehicle manufacturers require axles designed and developed for their specific applications. As axle design is becoming increasingly specialised, customers are increasingly raising their aspirations in terms of performance an reliability. For this reason, they are turning to specialists such as GKN Axles Ltd who have the ability to provide axles for a wide variety of vehicles。
Since the 1970s, however, in common with virtually all other suppliers to the high volume producers in the motor industry, GKN has radically modified its approach to suit the prevailing conditions as they change through the 1980s and on into the 1990s. Its aim now is at supplying complete axle assembles, including, for example, the brakes, all designed and fully developed for and integrated, as a matter of course, into specific vehicle designs including, in particular, those for the specialist market.
Emphasis is now on rationalization of materials, methods and components. This overall change has been necessary because of the greatly in creased sophistication demanded of the modern vehicle, in terms of overall efficiency, compactness, light weight, reliability, durability, refinement and maintenance-free operation. Another area into which GKN Axles has expanded is the supply of components and assemblies such as limited-slip differentials, ball-joints, transfer boxes, gears and some types of suspension.
?For off-road operation, the duty cycles may be entirely different in both torsional and beam loading-denpending on the application. For example, some types of vehicle spend a considerable proportion of their running time at high torque in low gear. In most circumstances, the terrain may be such that the tyres tend to slip more readily than on tarmac; in others, however, for example in fairly firm sandy screes, it may allow tyres to bite into it, and thus lead to torsional fatigue loading significantly greater than on smooth roads. Vertical and lateral loading, too, may be much more severe, though this dose depend to a major extent on speeds. Shock loading can also affect braking and acceleration torques though, again, such effects are speed-dependent.
Host reduction gear effect is to be used to reduce the rotation rate that the transmission shaft sends in but to enhance revolution moment of torsion , changes drive direction with moment of torsion , passes on to half axes after differential mechanism and. The host reduction gear structure form is that the form is different but different according to gear wheel type , reduction gear mainly. Host reduction gear gear wheel has helix cone forms such as gear wheel , hypoid gear , column gear wheel and worm gear worm mainly.
Pair of level host reduction gear is compared with single stage , the gap may be 7 ~12 transmission ratio , i0 each other at the same time in swear to be away from a field 12. But the dimension , mass are without exception bigger , cost is higher. It applies to middle, heavy type freight train , go-anywhere vehicle and motor bus mainly go ahead.
Dyadic overall pair of level host reduction gear has the various structure scheme: First order is a cone gear wheel , the second stage is a column gear wheel; First order is a cone gear wheel , the second stage is epicyclic gear; First order is epicyclic gear , the second stage is a cone gear wheel; First order is a column gear wheel , the second stage is a cone gear wheel.
Horizontal , askew, face and droop over to the three kinds to first order for the cone gear wheel , the second stage are that pair of column gear wheel level betokens reduction gear, but has direction arrangement scheme.
Direction level arrangement can use the assembly drooping over to outline dimension diminution , reducing the automobile quality heart altitude thereby, makes the direction dimension increase by but , that the use on long distance between shafts automobile but appropriate diminution transmission shaft length, is harmful for short distance between shafts automobile's to put arrangement together but, may make a transmission shaft short , leads to a universal transmission shaft intersection angle enlarge. Droop over to arranging a messenger to drive the bridge direction dimension diminution, may diminish a universal transmission shaft intersection angle, since but host reduction gear shell fixes superjacent in bridge shell , make not only droop over enhance to outline dimension, and have reduced bridge shell stiffness , have been harmful for gear wheel to work. This arrangement but easy to be versed in style driving a bridge arrangement. Arranging bridge shell stiffness and improving to the transmission shaft is slanting to arrangement advantageous.
When assigning a transmission ratio in pair of level host reduction gear having the cone gear wheel and the column gear wheel, the column gear wheel is 1.4 ~ like the ratio auxiliary and boring subsidiary gear wheel transmission ratio 2.0, and the cone gear wheel is 1.7 ~ like subsidiary transmission ratio 3.3, such axial loading may diminish a cone when the gear wheel is engaged and effect loading on the driven cone gear wheel and the column gear wheel, may make the active cone gear wheel tooth number appropriate increasing by at the same time , make whose supporting axis neck dimension appropriate enlarge, To improve whose supporting stiffness, improve falling-in stationarity and the job reliability.
?For modern axles, choice of gear lubricant can be critical. In cars operating at high speeds on motorways, axle oil temperature can ultimately rise even higher than 130℃,so venting of the casing is important. In principle, the oil in the base of the casting is swept around over the crownwheel and then forwards through the two bearings that carry the pinion. Consequently, both the shapes and dimensions of the clearances between the crownwheel and casing can be critical, and adequate drainage has to be provided for the oil to flow, through channels cored in the pinion bearing housings, back to the base of the casing.
? Within the gear carrier unit, taper roller bearings are employed almost universally for carrying the input pinion. They have a large load capacity within a small envelope, and can be preloaded for accurate and stable positioning of the gears. For pinion flange seals where resistance to high temperatures at relatively high speeds is essential, polyarcylate may be specified, but the abrasive conditions Viton is generally preferred.
That the cone gear wheel tooth goes over width face to face can not enhance gear wheel intensity and life-span , is able to lead to tooth ditch unexpected turn of events small end because of cone gear wheel gear teeth on the contrary narrow the cutting knife the top of the head face width arousing is too narrow and the point of a knife round angle is too small. Like this , not only, have diminished the tooth radical circle radius , have enlarged strain all together, life time having reduced a cutter. Besides , when assembling, have location deviation or wait for cause since fabrication , heat treatment are deformable, loading concentrates minor in gear teeth end when making a gear wheel work , is able to arouse gear teeth holding untimely damage and weary loss for a short time. That besides, the tooth goes over width face to face also is able to arouse assembling space diminution. The flank of a tooth is too narrow but , the gear teeth outside abrasion resistance meeting reduces.
For the running-in improving the new gear wheel, prevent the person from dying in working to Model T wear appear on initial stage , bruising , gluing together or barking, cone gear wheel bonderizing being 0.005 ~ 0.020 mm in heat treatment and finish machining aftercrop, thickness handles or the copper facing , the tin plating handle. The ball carrying out strain on the flank of a tooth gushing is sold at reduced prices , may improve 25%'s gear wheel life-span. To the high speed gear wheel sliding, may be in progress a sulfur oozing handling to improve abrasion resistance. Rub a factor but notable sulfur queen lessening oozes, even if lubricating condition is relatively poor , also, can prevent the flank of a tooth bruise from facing , barks to die and glue together.
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