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1、译文标题货车主减速器原文标题Truck Main Reduction Gear作 者Martin Balvin译名国籍原文出处Core 网货车主减速器在能源竞争激烈的二十世纪七十年代初,汽车业不得不将注意力越来越多地 定格在改进产品的质量上,但仍然维持其尽可能低的价格。在此之前,吉凯恩车 桥有限公司占据着最佳经济规模的优势,他们是最具竞争力的公司,在价格允许 范围内生产极具竞争力的不同类型车轴,使所有客户的需求可以得到满足,所有 类型的车轴都可以制造。但由于汽车制造商并没有经历过这样一个非常注重燃油 经济性的时期,因此,对重量轻的要求,这些标准车轴似乎可满足所有条件,满 足各种各样的应用。现在
2、汽车制造商需要车轴设计和开发的具体应用。轴设计正 变得越来越专业化,在性能的可靠性方面,客户越来越多地提高自己的期望。出 于这个原因,他们在找一个能提供各种车辆轴的公司。然而自二十世纪七十年代以来,在几乎所有其他汽车行业供应商的技术里, GKW根本上改变了它的原有的方法, 从而来以适应当前的环境,满足不同汽车的 需求,他们在二十世纪八十年代和九十年代的生产目的是提供完整的轮轴安装, 其中包括,刹车、所有的设计和整合、具体的汽车设计,以及为专业市场特别设 计的各种刹车、轮轴以及整合,甚至包括具体的汽车设计。现在的重点是选择合理化的材料,方法和内容途径。总的改革是必要的,对 于复杂性很大的现代化汽
3、车,需要考虑总体的效率,紧凑性,汽车的质量要轻, 考虑汽车的可靠性,汽车的耐用性,汽车的完善性以及汽车的免维护运行的能力。 在另一个方面,GKNI供的车轴是扩大了供应的部件和组件,如限滑差速器,球关 节,齿轮和某些类型的悬挂架。对于越野车,某些车辆设计公司花费了相当多的精力在较低齿轮但高扭矩的 齿轮设计上。在大多数情况下,多变的地形可能使这样的汽车轮胎发生打滑等现 象。例如,在相当坚硬的沙质路面上,它可能允许轮胎咬进去,轮胎可以陷入地 面内,从而使扭转疲劳显著大于在平稳的道路行驶,也就是说增大了轮胎的抓地 能力。虽然在很大程度上这种抓地能力,这种与地面交合的能力取决于汽车的速 度,但汽车速度过
4、大的话,汽车的纵向和横向打滑发生的可能性也会将更加的严 重。冲击负荷也会影响刹车和加速扭矩,车速过大造成的刹车不平稳,速度过大 同时会需要更大的发动机转矩这都会增加发动机的冲击负荷,这种冲击负荷影响 是取决于速度的。准双曲面齿轮传动是锥齿轮传动中的普遍形式,而螺旋锥齿轮传动中的螺旋锥齿轮是准双曲线齿轮的一种特殊情况。他们的优点是齿轮的具体比例较大,齿 轮体积较大,齿轮的齿与齿之间的啮合区域也较大,这种锥齿轮传动所具有的优 点就是低噪音,这种锥齿轮他们从本质上是强度更大,硬度更大,齿轮的运转更持 久齿轮的使用也更耐用。汽车主减速器的作用是用来降低传动轴传来的转速而增大旋转扭矩,并将扭 矩改变传动
5、方向,经差速器传给半轴,发动机传来的转速一般都比较大,通过减 速器,因传动比的存在可以降低差速器的转速同时增大齿轮的转矩。汽车主减速 器的结构和形式主要是根据齿轮的类型、减速器形式不同而不同,不同的结构形 式不同的齿轮类型所对应的汽车减速器不同。汽车主减速器的齿轮主要有螺旋锥 齿轮、双曲面齿轮、圆柱齿轮和蜗轮蜗杆等形式。双级主减速器与单级主减速器相比,在保证离地间隙相同时可得到更大的传 动比,传动比i0 一般为712。但是双击主减速器尺寸、质量均较大,这种减速 器的成本也较高。这种双级主减速器主要应用于中型、重型货车、越野车和大客 车上。整体式双级主减速器有多种结构方案:第一种方案是,第一级传
6、动齿轮为锥齿 轮,第二级传动齿轮为圆柱齿轮;第二种方案是,第一级传动齿轮为锥齿轮,第二 级传动齿轮为行星齿轮;第三种方案是,第一级传动齿轮为行星齿轮,第二级传 动齿轮为锥齿轮;第四种方案是,第一级传动齿轮为圆柱齿轮,第二级传动齿轮 为锥齿轮。对于第一级传动齿轮为锥齿轮、第二级传动齿轮为圆柱齿轮的双级主减速器, 又有不同的布置方案,具体可有纵向水平布置方案、斜向布置和垂向布置三种布 置方案。纵向水平布置可以使总成的垂向轮廓尺寸减小,使汽车减速器的整体尺寸在 水平方向上减小,从而降低汽车的质心高度,但与此同时使纵向尺寸增加使汽车 变得更宽,但这种缺点在不同的汽车上使用可以变劣势为优势,当用在长轴距
7、汽 车上时可适当减小传动轴的长度,但不利于短轴距汽车的总布置,如果布置在短 轴距汽车上会使传动轴过于短,导致万向传动轴的夹角加大。垂向布置的减速器 可以使驱动桥的纵向尺寸减小,与此同时可减小万向传动轴的夹角,但由于这种 垂向布置的主减速器壳固定在桥壳的上方,这种布置形式不仅使垂向轮廓尺寸增 大,而且降低了桥壳的刚度,这种垂向布置形式不利于齿轮工作。但是这种布置 形式也有他的优势,虽然这种布置降低了桥壳的刚度不利于齿轮工作,但是可便 于贯通式驱动桥的布置。而斜向布置对传动轴布置和提高桥壳刚度都有利,可以 说是具有了垂直布置形式和纵向布置形式的优点。在具有锥齿轮和圆柱齿轮的双级主减速器中,需要分配
8、两级传动比的比值各 为多少,在分配传动比时,我们根据以往的经验和设计数据显示,让圆柱齿轮副 和锥齿轮副传动比的比值一般应为 1.42.0 ,而且锥齿轮副传动比一般为 1.73.3,这样分配传动比的优点是可减小锥齿轮啮合时的轴向载荷,与此同时可使作 用在从动锥齿轮及圆柱齿轮上的载荷减小,同时可使主动锥齿轮的齿数适当增多, 增加了主动锥齿轮的齿数使其支承轴颈的尺寸适当加大,以改善其支承刚度,提 高齿轮间啮合的平稳性和工作可靠性。现代齿轮设计中,齿轮润滑油的选择是至关重要的。汽车运行在高速公路上,车桥油温可以最终上升到很高的温度,有时润滑油的油温甚至会高于130c ,所以在设计中保持车桥外壳的通风良
9、好也是很重要的。这种良好的通风性可以通过 两个轴承携带的小齿轮来达到改善的目的。因此,齿轮的形状和齿轮尺寸之间的 间隙,套管等的设计可能都是至关重要的,在减速器设计时,需要有足够的排水 能力,水冷却的水道,油冷的油道设计都至关重要。在设计中必须提供的润滑油 的流向,油液通过渠道流入小齿轮轴承座,再回到套管。在齿轮的轴承选择中,圆锥滚子轴承普遍应用在齿轮的设计中。因为圆锥滚 子轴承他们有较大的承载能力,具有较为良好的通过稳定性、和较为准确的定位。 法兰密封的齿轮对于抗高温和相对较高的速度是至关重要的。在齿轮设计中锥齿轮齿面过宽并不能增大齿轮的强度和寿命,反而会导致因 锥齿轮轮齿小端齿沟变窄引起的
10、切削刀头的情况,与此同时齿面过宽还会导致切 削刀头顶面宽过窄及刀尖圆角过小。这样,不但减小了齿根圆半径,加大了应力 集中,从而还降低了刀具的使用寿命。止匕外,在安装时由于安装位置偏差或着由 于制造、热处理变形等原因的存在,各种加工制造误差也有可能累积,导致加工 误差大,使齿轮工作时载荷集中于轮齿小端,会引起轮齿小端由于应力集中,磨 损严重等情况,使其过早损坏和疲劳损伤。另外,齿面过宽也会引起装配空间的 减小。但是也不是说齿面越小越好,齿面若是过窄,轮齿表面的耐磨性会降低, 从而使齿轮的耐磨性下降,强度不足等情况的,从而影响减速器的正常工作。为改善新齿轮的磨合能力,防止其在运行初期出现早期的磨损
11、、擦伤、胶合 或咬死等情况,锥齿轮设计时在选择加工处理时应特别注意,在热处理及精加工 后,要作厚度为0.0050.020mm的磷化处理或镀铜、镀锡处理。对减速器锥齿面 进行应力喷丸处理,这种处理方式可提高齿轮 25%的使用寿命。对于在运行过程 中滑动速度高的齿轮,可进行渗硫处理以提高耐磨性。渗硫后齿轮间的摩擦因数 可显著降低,即使齿轮的润滑条件变得较差,也能防止齿面擦伤、咬死和胶合的 情况。Truck Main Reduction GearIn the highly competitive period following the energy crisis of the early 1970
12、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
13、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
14、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, th
15、ey are turning to specialists such as GKN Axles Ltd who have the ability to provide axles for a wide variety of vehicles oSince 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 pre
16、vailing 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, thos
17、e 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, durabil
18、ity, 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 differ
19、ent 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
20、, 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 loadin
21、g 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 ,
22、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 a
23、nd 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
24、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;
25、 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 l
26、evel 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 be
27、tween shafts automobile but appropriate diminution transmission shaft length, is harmful for short distance between shafts automobiles 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
28、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
29、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
30、 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 e
31、ngaged 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-insta
32、tionarity 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 C ,so venting of the casing is important. In principle, the oil in the base of the casting is swe
33、pt 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 th
34、e 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.
35、 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-spa
36、n , 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 too
37、th 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 t
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