1 附 錄 A Truck Main Reduction Gear In the highly competitive period following the energy crisis of the early 1970s, 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 2 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. Hypoid gear systems are more commonly used than spiral bevels. Their principle advantages are that pinions of a specific ratio are bigger, their teeth profiles are of large radius, they are inherently stronger and more durable, their meshing areas are larger, and they generate less noise 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 3 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 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 4 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. 5 附 錄 B 重型卡車主減速器 在 能源 競爭激烈的 二十世紀七十 年代初，汽車業不得不將注意力越來越多地 定格在 改進產品的質量 上 ，但仍然維持其價格盡可能低。在此之前 ， 吉凱恩車橋有限公司占據 最佳經濟規模的優勢， 在 價格 允許 范圍 內 生產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。 但 由于汽車制造商并沒有 經歷 過 這樣一個非常注重燃油經濟性 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，滿足各種各樣的應用。現在汽車制造商需要車軸設計和開發的具體應用。軸設計正變得越來越專業化，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 供應商的 技術里 ， GKN從根本上改變了它的辦法，以適應當前的條件， 他們在二十世紀八十年代和九十年代的生產目的是提供完整的輪軸安裝， 其中包括，剎車 、 所有的設計和整合 、 具體的汽車設計， 以及 為專業市場特別 設計的 。 現在的重點是合理化的材料，方法和內容。總的改革是必要的， 對于 復雜性 很大的現代汽車， 考慮 總體效率，緊湊，重量輕，可靠性，耐用性，完善和免維護運行。另一個領域 ， GKN 提供的 車軸是擴大了供應的部件和組件，如限滑差 速器 ，球關節，齒輪和某些類型的 懸掛架 。 對于 越野 車 ，某些車輛 設計公司 花費了相當 多 的時間在 較 低齒輪 但 高扭矩 的設計上 。在大多數情況下，地形可能 使這樣的輪胎打滑。 例如，在相當堅 硬的 沙質 路面 ，它可能允許輪胎咬進去，從而 使 扭轉疲勞 顯著 大于 在平穩 的道路 行駛 。雖然 在大程度上這 取決于 速度 ， 但 縱向和橫向 打滑時將 更嚴重。沖擊負荷也會影響剎車和加速扭矩，這種影響是 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，螺旋錐齒輪是它的一種特殊情況 。他們的優點是齒輪的具體比例較大，其嚙合區較大，而且低噪音 ,他們本質上是更強大，更持久和 更耐用。 6 主減速器的作用是用來降低傳動軸傳來的轉速而增大旋轉扭矩，并將扭矩改變 傳動 方向，經差速器傳給半軸。 主減速器的結構形式主要是根據齒輪類型、減速器形式不同而不同。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 單級相比，在保證離地間隙相同時可得到大的傳動比， i0 一般為7 12。但是尺寸、質量均較大，成本較高。它主要應