裝配圖大直徑樁基礎(chǔ)工程成孔鉆具(論文+DWG圖紙),裝配,直徑,樁基礎(chǔ),工程,成孔鉆具,論文,dwg,圖紙 Horizontal Directional Drill Hole Drill end of the study and application of a drill hole end of a composition and function. Construction of drill hole orientation : drill pipe, a launcher tube and a guide to accommodate bit. Construction of drill hole orientation with drilling, to change, through magnetic and drilling fluid delivery functions. Coordinated by computer control, in strict accordance with the design of the track has been completed oriented hole. Drilling is drilling high pressure liquid jet cutting board and bit accomplished; Bits board and the installation of boards of drilling teeth. Rotary drilling bit at the time supporting Cutting role in promoting the drill pipe at changes to the role; transmitters placed to accommodate tube launcher, to accommodate the opening of a Magnetic planters, Non-metallic materials and sealed to prevent the entry of high pressure drilling fluid, launch vehicles by the electromagnetic field Magnetic tank fired. Internal drill pipe and drill should provide sufficient access to meet the drilling fluid flow needs. 2, the construction of bore hole : drill pipe, the first to expand, the rotary joint drill pipe and back to Rafah. When the guide hole drilling is completed, unloaded oriented bit, to accommodate tube launchers and connect with reverse bore bit and rotary joint, Then after the rotary joint drill pipe connected to Rafah, to Reamer drilling. The large diameter holes, a number of bore drilling, hole diameter gradually expanded to the size requirement. 3, back to Rafah Pipeline Construction hole : drill pipe to Rafah, to expand first, rotating joints and pipe-drawing tools. When the bore drilling is completed, the drill pipe to Rafah after expanding access to the first and rotary joint, After the rotary connector connected pipe-drawing tools and the laying of pipelines to be anti-expansion Pipeline. 2, the main drill a research and application, the drill pipe drilling pipe construction quality is the key to success. Construction of the pipe and caused damage to the drill pipe connecting the end of drill hole of the lost, whether to expand or expensive first mud motors, and pipelines. As the drill pipe construction of HDD technology to the success of a basic role, in recent years, drill pipe manufacturers have continued to adopt advanced technology to improve the structure of the pipe to improve its performance and quality. Currently, the main HDD drill pipe into the overall style and welded two structural forms. Friction welding type of drill pipe drilling pipe achieve the best combination of structure, which means that in order to meet different needs. Performance of different materials can be used in different parts of the pipe. Friction welding drill pipe with high mechanical properties, wear resistance, light weight, good flexibility, a convenient way to different forms of threaded joints with different specifications of the pipe welding portfolio. Mount Sassafras drill pipe-welding technology is the key to the quality of welding, welding and heat treatment process control properly, Friction welding connection strength should reach even higher than the base material itself intensity. To ensure the quality of welding. foreign manufacturers for the manufacture of drill pipe friction welding equipment has been used advanced computer control and data recording technology. Through the monitoring system to ensure that every root of all drill pipe welding parameters in accordance with prior to the numerical implementation. In other words, a group of drill pipe in any one drill pipe, are strictly controlled in the context of tolerance, by the computer monitoring system to ensure that the welding performance consistency. And drill pipe through a single test, a number of drill pipe to provide each of the roots of the pipe complete, reliable performance data. After welding overall electromagnetic induction heat treatment, the whole process is an important stage. In recent years, considerable research through research and testing, now be able to make a welded seam mechanical properties to meet or surpass the performance of the base material itself, including durability, welding safety aspects. In order to improve the surface hardness thread, thread itself to prevent any possible occlusion, the post-processing on the surface of the nipple. Thread particular part should be carried out nitriding treatment. Drill pipe used in the manufacture of steel pipes used high-grade seamless steel tubes, and after quenching and tempering. Friction welding drill pipe Another advantage is being able to drill pipe internal drilling fluid channel design. Within which the nipple holes in the design of the Corridor full consideration to minimize the liquid through the hydraulic losses Special connecting thread is the first reduction of the loss, will greatly enhance the drilling fluid system efficiency. Threaded joints in the design using the top of the basket, the landscape of conical threaded design that can connect to increase strength, can in no additional washers with the help of the enclosed play a very good role. Practice shows that the use of more powerful drill holes and underground drilling equipment, maximum hole diameter and the smallest curvature radius, on the special needs of high-quality design of the drill pipe to meet the construction requirements. 2, guided boring BHA (1) Universal : Universal Detection device for capacity, Variable bit to the plate-and cutting tools. It is normally used in soft soil and backfill soil construction, replacement of hard-bit teeth, hard formation for the construction, including the hard soil, rock, gravel and soft rock. (2) Rigid-formation comprising : Definitive detection devices installed capacity, belt-injection tube bending and (a) separate from the spray head, apply to soft soil controllable jet construction; (b) rock drill, as applied to drilling mixed layer, In hard rock section allows rotary drilling bits. (3) soft-rock composition : Definitive detection devices installed capacity, hammer, Hammerhead applicable to the hard ground and soft rock drilling high penetration and to (4) Rock : Definitive detection devices to accommodate devices, change the connector, mud motors, bits of rock to rock Drilling 3, used to expand drilling hole (1) with long shafts to extend the first features : 30 degrees cone shape, conducive to efficient cutting and squeezing soil; access to a variety of back end and threaded connection forms; forward and backward drilling fluid spray nozzle of the can for TC-rock teeth; Groove can be used to efficiently remove cuttings; Dimensions 8 "(200mm) a 20" (500mm) applicable to the general condition of the project, in the density of clay, gravel and mud-rock clay soil (gravel, cobble, etc.) construction, both warm-cutting with a knife and squeezed Cone for the composite function with high efficiency of the construction. Installation TC rock cutting teeth, can improve cutting. Generally applied to medium hardness of the soil, and are particularly suited to the hard rock and soil layer construction. (2) mid-knife to expand on features : open drilling body 30 degrees conical cutting arm, In comparison with the extrusion is excellent BTA and mixed role. Is a unique way to expand is omnipotent, in the sand, soft soil, clay and concrete compound layer construction with excellent performance, to be effective so that the soil mixed with the mud flow into the mixture has the ideal BTA and powerful mixing. Dimensions 8 "(200mm) a 20" (500mm). (3) spin-barrel-back expansion device features : suitable for medium and large drilling rig; open drilling body, three-arm design. with high efficiency and the cutting ability of BTA. Replacement rock cutting teeth can be replaced by the forward and backward nozzle, the standard size of 12 "(300mm). Welding with industry standard API 5C6. generally used, broken clay soil superior extrusion type, This trace was excellent cutting properties and BTA, often with a barrel-to expand the use of devices together. (4) barrel-type device to expand features : suitable for medium and large rigs. 30 degrees around the cone; Replacement rock cutting teeth; both before and after the end can be replaced with the nozzle; standard size 12 "(300mm). Barrel - type device to expand in clay, gravel soil, aggregates and construction with the rock cutting and excellent extrusion properties, used mainly for extrusion soil (soft clay, peat), in soil squeezed out holes and maintain. 水平定向鉆機(jī)孔底鉆具的研究與應(yīng)用 湖南工業(yè)大學(xué)機(jī)械工程學(xué)院機(jī)本0302班12號(hào) 李洪光（譯） 一、孔底鉆具的組成與功能 １、導(dǎo)向孔施工 鉆具組成：鉆桿、發(fā)射器容納管和導(dǎo)向鉆頭。 導(dǎo)向孔施工鉆具具有鉆孔、變向、通磁和輸送鉆液的功能。通過(guò)人機(jī)協(xié)調(diào)控制，嚴(yán)格按已設(shè)計(jì)的軌跡完成導(dǎo)向孔施工。鉆孔施工是以高壓鉆液射流和鉆頭板切削共同完成的；鉆頭板以及安裝板上的鉆牙，在鉆頭旋轉(zhuǎn)鉆進(jìn)時(shí)起輔助的切削作用，在鉆桿推進(jìn)時(shí)起變向作用；發(fā)射器容納管用來(lái)放置發(fā)射器，在容納管上開(kāi)有通磁槽，并用非金屬材料密封以防止高壓鉆液進(jìn)入，發(fā)射器發(fā)射的電磁波經(jīng)通磁槽向外發(fā)射。鉆桿和鉆頭內(nèi)部應(yīng)提供足夠大的通道以滿足對(duì)鉆液流量的需求。 ２、擴(kuò)孔施工 ??? 鉆具組成：鉆桿、回?cái)U(kuò)頭、旋轉(zhuǎn)接頭和回拉鉆桿。 當(dāng)導(dǎo)向孔鉆進(jìn)完成后，卸下導(dǎo)向鉆頭、發(fā)射器容納管，接上反向擴(kuò)孔鉆頭和旋轉(zhuǎn)接頭，然后在旋轉(zhuǎn)接頭后接上回拉鉆桿，進(jìn)行回拉擴(kuò)孔鉆進(jìn)。對(duì)直徑較大的孔，可進(jìn)行多次擴(kuò)孔鉆進(jìn)，使鉆孔直徑逐漸擴(kuò)大至尺寸要求。 ３、回拉鋪管施工 鉆具組成：回拉鉆桿、回?cái)U(kuò)頭、旋轉(zhuǎn)接頭和拉管頭。 當(dāng)擴(kuò)孔鉆進(jìn)完成后，在回拉鉆桿后接上回?cái)U(kuò)頭和旋轉(zhuǎn)接頭，在旋轉(zhuǎn)接頭后接上拉管頭和待鋪設(shè)的管線進(jìn)行反擴(kuò)鋪管。 二、主要鉆具的研究與應(yīng)用 １、鉆桿 鉆桿的質(zhì)量是施工成功的關(guān)鍵，施工中鉆桿的損壞將導(dǎo)致與鉆桿連接的孔底鉆具的丟失，無(wú)論是回?cái)U(kuò)頭還是價(jià)格昂貴的泥漿馬達(dá)、管線等。由于鉆桿對(duì)ＨＤＤ施工技術(shù)的成功起著基礎(chǔ)性的作用，所以近年來(lái)，鉆桿制造商們不斷采用先進(jìn)技術(shù)致力于改進(jìn)鉆桿的結(jié)構(gòu)，提高其性能和質(zhì)量。 目前，ＨＤＤ鉆桿主要分為整體式和焊接式兩種結(jié)構(gòu)形式。 摩擦焊接式鉆桿實(shí)現(xiàn)了鉆桿最佳結(jié)構(gòu)組合，這就意味著為滿足不同需要的、不同性能的材料能夠被用來(lái)做鉆桿的不同部位。磨擦焊接鉆桿具有很高的機(jī)械性能、耐磨性能，而且重量輕、柔韌性好，可方便地實(shí)現(xiàn)不同形式的螺紋接頭與不同規(guī)格的鋼管的焊接組合。 摩檫焊接式鉆桿的技術(shù)關(guān)鍵是焊接質(zhì)量，如果焊接及熱處理過(guò)程控制得當(dāng)，摩擦焊接的連接強(qiáng)度應(yīng)達(dá)到甚至高于母材本身強(qiáng)度。 為了保證焊接質(zhì)量，國(guó)外制造商用于制造摩擦焊接鉆桿的設(shè)備均采用先進(jìn)的計(jì)算機(jī)監(jiān)控和數(shù)據(jù)記錄技術(shù)。通過(guò)監(jiān)控系統(tǒng)確保每根鉆桿所有焊接重要參數(shù)均按照預(yù)先給定的數(shù)值執(zhí)行。也就是說(shuō)，一批鉆桿中的任何一根鉆桿，均控制在嚴(yán)格的公差范圍內(nèi)，由計(jì)算機(jī)監(jiān)控系統(tǒng)確保其焊接性能的一致性。而且通過(guò)單根鉆桿試驗(yàn)測(cè)試，能夠提供一批鉆桿中的每根鉆桿的完整的、可靠的性能數(shù)據(jù)。 焊后整體電磁感應(yīng)熱處理，是整個(gè)處理過(guò)程的重要階段。近年來(lái)通過(guò)科研部門不斷研究與試驗(yàn)，目前能夠使得焊接后焊縫的機(jī)械性能達(dá)到甚至超過(guò)母材本身性能，包括耐久性能、焊接安全方面等。 為了提高螺紋表面硬度，防止螺紋本身產(chǎn)生任何可能的咬合，加工后的螺紋接頭的表面，特別是螺紋部分都要進(jìn)行滲氮處理。 用于制造鉆桿的鋼管采用高等級(jí)無(wú)縫鋼管，且經(jīng)過(guò)淬火和回火處理。 摩擦式焊接鉆桿另一好處是，可以對(duì)鉆桿內(nèi)部鉆液通道進(jìn)行設(shè)計(jì)。其中螺紋接頭內(nèi)孔通道的設(shè)計(jì)充分考慮了盡量減少液體通過(guò)時(shí)的液壓損失，特別是減少螺紋連接頭部分造成的損失，能大大提高鉆液系統(tǒng)的工作效率。 在螺紋接頭設(shè)計(jì)上采用了切去頂端的、園錐型的螺紋設(shè)計(jì)，這種設(shè)計(jì)既能增加連接強(qiáng)度，又能在不用附加墊圈的幫助下起到很好的密封作用。 實(shí)踐表明，要使用更強(qiáng)有力的孔底鉆具和鉆進(jìn)設(shè)備，獲得最大的鉆孔直徑和最小的曲率半徑，就需要特殊設(shè)計(jì)的高品質(zhì)的鉆桿以滿足施工要求。 ２、導(dǎo)向鉆進(jìn)鉆具組合 （１）通用型 組成：通用探測(cè)裝置容納器、變向鉆頭體和板式切削刀具。 通常用于中軟土壤和回填土層施工，可更換硬地型鉆頭牙齒，用于硬地層的施工，包括硬土、巖土、礫石和軟巖層。 （２）硬地層型 組成：通用探測(cè)裝置容納器、帶彎曲式噴射管和 （ａ）可分開(kāi)的噴射頭，適用于在軟土層可控噴射施工； （ｂ）巖石鉆頭，適用于混合層鉆進(jìn)，在堅(jiān)硬的部分允許巖石鉆頭旋轉(zhuǎn)鉆進(jìn)。 （３）軟巖層型 ? 組成：通用探測(cè)裝置容納器、錘體、錘頭 適用于在硬地面和軟巖層中進(jìn)行高穿透鉆進(jìn)和轉(zhuǎn)向 （４）巖石型 組成：通用的探測(cè)裝置容納器、轉(zhuǎn)換接頭、泥漿馬達(dá)、巖石鉆頭 適用于巖石層鉆進(jìn)施工 ３、回?cái)U(kuò)鉆進(jìn)用鉆具 （１）帶長(zhǎng)槽的回?cái)U(kuò)頭 特點(diǎn)： ３０度錐體形狀，有利于高效率的切削和擠壓土壤；可獲得多種螺紋和背端連接形式；向前和向后噴射鉆液的噴嘴為可換式；ＴＣ巖石牙齒；凹槽體用來(lái)高效率排除鉆屑；標(biāo)準(zhǔn)尺寸８＂（２００ｍｍ）一２０＂（５００ｍｍ） 適用于普遍的工程條件，在中密度粘土、礫泥粘土和含巖土壤（礫石、鵝卵石等）中施工，兼有飛旋刀式切割器和錐形擠擴(kuò)器的復(fù)合功能，具有很高的施工效率。 安裝ＴＣ巖石切削牙齒，可提高切削作用。普遍適用于中等硬度土層，特別適合在硬土和巖石土層中施工。 （２）飛旋刀式回?cái)U(kuò)器 特點(diǎn)： 開(kāi)放式鉆體，３０度錐型切削臂，與擠壓式相比具有極好的排屑和混合的作用。 是一種獨(dú)特地萬(wàn)能回?cái)U(kuò)器，在沙地、軟土層、粘土層和混凝料中施工具有極好的性能，可有效的使泥漿與土壤混合成流動(dòng)的混合物，具有理想的排屑和強(qiáng)大的混合作用。標(biāo)準(zhǔn)尺寸８＂（２００ｍｍ）一２０＂（５００ｍｍ）。 （３）旋桶式回?cái)U(kuò)器 特點(diǎn)： 適合于中大型鉆機(jī)；開(kāi)放式鉆體，三臂式設(shè)計(jì)，具有高效率的切削和排屑能力?？筛鼡Q巖石切削牙齒，可更換的向前和向后噴嘴，標(biāo)準(zhǔn)尺寸１２＂（３００ｍｍ），焊接符合ＡＰＩ工業(yè)標(biāo)準(zhǔn)５Ｃ６。 一般用于，破碎黏土型土壤優(yōu)于擠壓式，這種飛刀具有卓越的切削和排屑特性，常常與桶式回?cái)U(kuò)器一起使用。 （４）桶式回?cái)U(kuò)器 特點(diǎn)： 適合于中大型鉆機(jī)。３０度前后錐體；可更換的巖石切削牙齒；前后端均帶有可更換的噴嘴；標(biāo)準(zhǔn)尺寸１２＂（３００ｍｍ）。桶式回?cái)U(kuò)器在黏土、礫泥、混凝料和巖土中施工具有極好的切削和擠壓性能，主要用于擠壓土壤（軟黏土、泥炭土），在土壤中擠擴(kuò)出洞孔并保持. 10 GEAR Spur and helical gears. A gear having tooth elements that are straight and parallel to its axis is known as a spur gear. A spur pair can be used to connect parallel shafts only. Parallel shafts, however, can also be connected by gears of another type, and a spur gear can be mated with a gear of a different type. (Fig.1.1). To prevent jamming as a result of thermal expansion, to aid lubrication, and to compensate for avoidable inaccuracies in manufacture, all power-transmitting, gears must have backlash. This means that on the gear, and vice versa. On instrument gears, backlash can eliminated by using a gear split down its middle, one half being rotatable relative to the other. A spring forces the split gear teeth to occupy the full width of the pinion space. Helical gears have certain advantages; for example, when connecting parallel shafts they have a higher loadcarrying than spur gears with the same tooth numbers and cut with the same cutter. Because of the overlapping action of the teeth, they are smoother in action and can operate at higher pitch-line to the axis of rotation, helical gears create an axial thrust. If used singly, this thrust must be absorbed in the same blank. Depending on the method of manufacture, the gear may be of the continuous-tooth herringbone variety or a double-helical gear with a space between the two halves to permit the cutting tool to run out. Double-helical gears are well suited for the efficient transmission of power at highspeeds. Helical gears can also be used to connect nonparallel, non-intersecting shafts at any angle to one another. Ninety degrees is the commonest angle at which such gears are used. Worm and bevel gears. In order to achieve line contact and improve the loadcarrying capacity of the crossed-axis helical gears, the gear can be made to curve partially around the pinion, in somewhat the same way that a nut envelops a screw. The result would be a cylindrical worm and gear. Worm gears provide the simplest means of obtaining large rations in a single pair. They are usually less efficient than parallel-shaft gears, however, because of an additional sliding movement along the teeth. Because of their similarity, the efficiency of a worm and gear depends on the same factors as the efficiency of a screw. Single-thread worms of large diameter have small lead angles and low efficiencies. Multiple-thread worms have larger lead angles and higher efficiencies(Fig.1.2) For transmitting rotary motion and torque around corners, bevel gears are commonly used. The connected shafts, whose axes would intersect if extended, are usually but not necessarily at right angles to one another. When adapted for shafts that do not intersect, spiral bevel gears are called hypoid gears. The pitch surfaces of these gears are not rolling cones, and the ratio of their mean diameters is not equal to the speed Consequently, the pinion may have few teeth and be made as large as necessary to carry the load. The profiles of the teeth on bevel gears are not involutes; they are of such a shape that the tools for the teeth are easier to make and maintain than involute cutting tools. Since bevel gears come in, as long as they are conjugate to one another they need not be conjugate to other gears with different both numbers. 1 Early History of Gearing The earliest written descriptions of gears are said to have been made by Aristotle in the fourth century B.C. It has been pointed out that the passage attributed to Aristotle by some was actually from the writings of his school, in “Mechanical Problems of Aristotle”(Ca.280 B.C). In the passage in question, there was no mention of gear teeth on the parallel wheels, and they may just as well have been smooth wheels in frictional contact. Therefore, the attribution of gearing to Aristotle is, most likely, incorrect. The real beginning of gearing was probably with Archimedes who about 250 B.C. invented the endless screw turning a toothed wheel, which was used in engines of war. Archimedes also used gears to simu-early forms of wagon mileage indicators (odometer) and surveying instruments. These devices were probably “thought” experiments of Heron of Alexandria (ca. A.D.60), who wrote on the subjects of theoretical mechanics and the basic elements of mechanism. The oldest surviving relic containing gears is the Antikythera mechanism, so named because of the Greek island of that name near which the mechanism was discovered in a sunken ship in 1900. Professor Price of Yale University has written an authoritative account of this mechanism. The mechanism is not only the earliest relic of gearing, but it also is an extremely complex arrangement of epicyclic differential gearing. The mechanism is identified as a calendrical computing mechanism for the sun and moon, and has been dated to about 87 B.C. The art of gearing was carried through the European dark ages after the fall of Rome, appearing in Islamic instruments such as the geared astrolabes which were used to calculate the positions of the celestial bodies. Perhaps the art was relearned by the clock-and instrument-making artisans of fourteenth-century Europe, or perhaps some crystallizing ideas and mechanisms were imported from the East after the crusades of the eleventh through the thirteenth centuries. It appears that the English abbot of St.Alban’s monastery, born Richard of Wallingford, in A.D. 1330, reinvented the epicyclic gearing concept. He applied it to an astronomical clock, which he began to build at that time and which was completed after his death. A mechanical clock of a slightly later period was conceived by Giovanni de Dondi(1348-1364). Diagrams of this clock, which did not use differential gearing, appear in the sketchbooks of Leonardo da Vinci, who designed geared mechanisms himself. In 1967 two of da Vinci’s manuscripts, lost in the National Library in Madrid since 1830, were rediscovered. One of the manuscripts, written between 1493 and 1497 and known as “Codex Madrid I” , contains 382 pages with some 1600 sketches. Included among this display of Lenardo’s artistic skill and engineering ability are his studies of gearing. Among these are tooth profile designs and gearing arrangements that were centuries ahead of their “invention”. 2 Beginning of Modern Gear Technology In the period 1450 to 1750, the mathematics of gear-tooth profiles and theories of geared mechanisms became established. Albrecht Durer is credited with discovering the epicycloidal shape(ca. 1525). Philip de la Hire is said to have worked out the analysis of epicycloids and recommended the involute curve for gear teeth (ca. 1694). Leonard Euler worked out the law of conjugate action(ca.1754). Gears deigned according to this law have a steady speed ratio. Since the industrial revolution in mid-nineteenth century, the art of gearing blossomed, and gear designs steadily became based on more scientific principles. In 1893 Wilfred Lewis published a formula for computing stress in gear teeth. This formula is in wide use today in gear design. In 1899 George B.Grant, the founder of five gear manufacturing companies, published “A Treatise on Gear Wheels” . New inventions led to new applications for gearing. For example, in the early part of this century (1910), parallel shaft gears were introduced to reduce the speed of the newly developed reaction steam turbine enough to turn the driving screws of ocean-going vessels. This application achieved an overall increase in efficiency of 25 percent in sea travel. The need for more accurate and quiet-running gears became obvious with the advent of the automobile. Although the hypoid gear was within our manufacturing capabilities by 1916, it was not used practically until 1926, when it was used in the Packard automobile. The hypoid gear made it possible to lower the drive shaft and gain more usable floor space. By 1937 almost all cars used hypoid-geared rear axles. Special lubricant antiwear additives were formulated in the 1920s which made it practical to use hypoid gearing. In 1931 Earle Buchingham, chairman of an American Society of Mechanical Engineers (ASME) research committee on gearing, published a milestone report on gear-tooth dynamic loading. This led to a better understanding of why faster-running gears sometimes could not carry as much load as slower-running gears. High-strength alloy steels for gearing were developed during the 1920s and 1930s . Nitriding and case-hardening was introduced in 1950. Extremely clean steels produced by vacuum melting processes introduced in1960 have proved effective in prolonging gear life. Since the early 1960s there has been increased use of industrial gas turbines for electric power generation. In the range of 1000 to 14000 hp, epicyclic gear systems have been used successfully. Pitch-line velocities are form 50 to 100m/s(10000 to 20000 ft/min). These gear sets must work reliably for 10000 to 30000 hp between overhaule. In 1976 bevel gears produced to drive a compressor test stand ran stand ran successfully for 235h at 2984kw and 200m/s. form all indications these gears could be used in an industrial application if needed. A reasonable maximum pitch-line velocity for commercial spiral-bevel gears with curved teeth is 60m/s. Gear system development methods have been advanced in which lightweight, highly loaded gears are used in aircraft applications. The problems of strength and dynamic loads, as well as resonant frequencies for such gearing, are now treatable with techniques such as finite-element analysis, siren and impulse testing for mode shapes, and application of damping treatments where required. 齒 輪 直齒輪和斜齒輪 輪齒是直的、而方向又與其軸平行的齒輪稱作直齒輪。一對(duì)直齒輪只能用來(lái)連接平行軸。然而，平行軸也可以用其他形式的齒輪來(lái)連接，一個(gè)直齒輪可以同一個(gè)不同形式的齒輪互相嚙合，如圖1-1。 為了避免由于熱膨脹而出現(xiàn)的卡住現(xiàn)象；為了便于潤(rùn)滑和補(bǔ)償制造中不可避免的誤差，所有傳遞動(dòng)力的齒輪必須具有側(cè)向間隙。這就是說(shuō)在互相嚙合齒輪的節(jié)圓上，小齒輪的間隙寬度必須稍大于大齒輪的齒厚，反之亦然。在儀表齒輪上，可以利用從中間分開(kāi)的拼合齒輪來(lái)消除側(cè)向間隙，它的一半可相對(duì)于另一半轉(zhuǎn)動(dòng)。彈簧迫使拼和齒輪的齒占滿小齒輪間隙的整個(gè)寬度。 斜齒輪具有某些優(yōu)點(diǎn)。例如：連接兩平行軸時(shí)，斜齒輪比齒數(shù)相同、用相同刀具切削的直齒輪有較高的承載能力。由于輪齒的重迭作用，斜齒輪工作比較平穩(wěn)、允許比直齒輪有更高的節(jié)線速度。節(jié)線速度是節(jié)圓的速度。由于輪齒與旋轉(zhuǎn)軸傾斜，所以斜齒輪會(huì)產(chǎn)生軸向推力。如果單個(gè)使用，這一推力必須由軸承來(lái)承受。推力問(wèn)題可以通過(guò)在同一坯見(jiàn)切削兩組斜齒來(lái)克服。根據(jù)制造方法的不同，齒輪可以是連續(xù)人字形的，或者在兩列斜齒之間留一間隙的雙斜齒形的，以便切削刀具通過(guò)。雙斜齒齒輪非常使用于高速高效的傳遞動(dòng)力。 斜齒輪也能用來(lái)連接既不平行也不相交的相互成任何角度的軸。最常用的角度為。 蝸輪蝸桿和傘齒輪 為了使交叉軸斜齒輪獲得線接觸和提高承載能力，可以把大齒輪做成部分繞小齒輪彎曲，就象螺母套在螺桿上一樣，結(jié)果就形成一個(gè)柱形蝸桿和蝸輪。蝸輪蝸桿提供了獲得一對(duì)大速比齒輪的最簡(jiǎn)單的方法。然而，由于沿齒的附加滑動(dòng)使蝸輪蝸桿的效率通常低于平行軸齒輪。同樣，其效率還取決于影響螺紋效率的那些因素。大直徑的單頭蝸桿的導(dǎo)角很小，效率很低，而多頭蝸桿的導(dǎo)角較大，效率也比較高，見(jiàn)圖1-2。 為了使傳遞的轉(zhuǎn)動(dòng)和扭矩能轉(zhuǎn)一個(gè)角度，常常是用傘齒輪。所連的兩跟軸，如果延長(zhǎng)其軸線就會(huì)相交，它們通?；コ?。 兩軸不相交的螺旋傘齒輪稱作偏軸傘齒輪。這種齒輪的節(jié)面不是滾錐，它們的平均直徑比不等于速比。因此，小齒輪的齒數(shù)較小，其大小能適應(yīng)承載的需要。 傘齒輪的齒廓不是漸開(kāi)線形的。它們的形狀使切齒刀具比漸開(kāi)線刀具更易于制造和維修。由于傘齒輪是成對(duì)使用的，因此，只要它們能互相共軛，就不需要與齒數(shù)不同的其他齒輪共軛。 圖1直齒輪 圖2螺蝸輪蝸桿船 齒輪的早期發(fā)展史 有關(guān)齒輪的最早的論著認(rèn)為，齒輪是在公元前四世紀(jì)由Aristotle發(fā)明的。書中指出：齒輪是由Aristotle發(fā)明的這段文字實(shí)際上出自其母校的論著：“關(guān)于Aristotle的機(jī)械問(wèn)題”（約公元前280年）。問(wèn)題是在有關(guān)章節(jié)中，并沒(méi)有體積在平行的輪子上有齒輪，而只是光華的輪子，靠摩擦接觸。因此，認(rèn)為齒輪是由發(fā)明的說(shuō)法不見(jiàn)得是正確的。 實(shí)際上，齒輪機(jī)構(gòu)可能是在公元前約250年由Archimedes發(fā)明的，他發(fā)明了螺桿用以驅(qū)動(dòng)一個(gè)帶齒的輪子，這種輪子用于軍用發(fā)動(dòng)機(jī)。Archimedes也用齒輪來(lái)仿造天體比例儀。Archimedian螺旋機(jī)構(gòu)一直用語(yǔ)測(cè)程計(jì)及高度和角度測(cè)量裝置，這是早期使用的四輪馬車?yán)锍逃?jì)（里程表）和測(cè)量?jī)x。這些裝置被認(rèn)為是埃及及亞力大實(shí)驗(yàn)裝置，他寫了關(guān)于理論力學(xué)及基本機(jī)械零件的論著。所查到的最早的齒輪的遺物是Antikythera機(jī)構(gòu)，這是根據(jù)希臘島嶼的名字而命名的，因?yàn)檫@中機(jī)構(gòu)是1900年在靠近Antikythera島發(fā)現(xiàn)的沉船中出現(xiàn)的。yale大學(xué)的Price教授寫了論述這一機(jī)構(gòu)的權(quán)威專著。這一機(jī)構(gòu)不僅是齒輪傳動(dòng)機(jī)構(gòu)的最早遺物，也是極為復(fù)雜的行星齒輪傳動(dòng)機(jī)構(gòu)，它也被認(rèn)為是用于表示太陽(yáng)和月亮運(yùn)行的日歷計(jì)算機(jī)構(gòu)，并可追溯到公元前87年。在羅馬衰敗之后的蕭條時(shí)期，齒輪傳動(dòng)技術(shù)傳遍了整個(gè)歐洲并在穆斯林儀表中得到應(yīng)用，如計(jì)算天體位置的齒輪觀測(cè)儀。也許是這一技術(shù)又被14世紀(jì)歐洲的鐘表儀器制造專家再次采用，也許是一些奇特的構(gòu)思，在十一世紀(jì)至十三世紀(jì)的改舉運(yùn)行之后，這些機(jī)構(gòu)又從東方引入。 似乎是英國(guó)St.Alba的住持于1930年又發(fā)明了行星齒輪的構(gòu)思，他將其用于天文鐘表，并實(shí)施建造，但當(dāng)他死后才竣工。 稍后機(jī)械鐘表是由Giovanni de Dondi設(shè)計(jì)的。根據(jù)Lenonardo da Vinci手稿，鐘表設(shè)計(jì)圖中并沒(méi)有差動(dòng)齒輪傳動(dòng)系統(tǒng)，而他自行設(shè)計(jì)了齒輪機(jī)構(gòu)。1967年又發(fā)現(xiàn)了1830年在國(guó)立圖書館失竊的davinci的兩本手稿，其中一本為“CodexMadridl”,是1493年至1497年間寫的，共382頁(yè)約1600幅圖，展示Leonardo的藝術(shù)及工程才華的便是他對(duì)齒輪機(jī)構(gòu)的研究，其中一些便是齒廓設(shè)計(jì)及齒輪傳動(dòng)機(jī)構(gòu)設(shè)計(jì)，但這些機(jī)構(gòu)早在幾百年前就有了。 現(xiàn)代齒輪技術(shù)的開(kāi)端 1450～1750年間，建立了輪齒廓形的數(shù)學(xué)表達(dá)式及齒輪傳動(dòng)機(jī)構(gòu)的理論。 Albrecht Du rer設(shè)計(jì)了外擺線齒形，Philip dela Hire對(duì)擺線齒輪作了分析，并推薦輪齒采用漸開(kāi)線形狀，Leonard Euler研究了相配合齒輪定律根據(jù)這一定律可以獲得穩(wěn)定的速比。 由于19世紀(jì)中葉的工業(yè)革命，齒輪傳動(dòng)機(jī)構(gòu)被廣泛采用，齒輪設(shè)計(jì)也符合科學(xué)原理。1893年Wilfred Lewis發(fā)表了計(jì)算輪齒應(yīng)力的公式，這一公式至今仍在齒輪設(shè)計(jì)中廣泛應(yīng)用。1899年George B.Grant這位五家齒輪公司的創(chuàng)始人發(fā)表了關(guān)于齒輪的專題論文。新的發(fā)明使得齒輪傳動(dòng)機(jī)構(gòu)有了新的應(yīng)用。例如在本世紀(jì)早期，將平行軸齒輪傳動(dòng)機(jī)構(gòu)用于當(dāng)時(shí)研制的反應(yīng)式汽輪機(jī)降速，它足以帶動(dòng)遠(yuǎn)洋船的傳動(dòng)螺桿。這一應(yīng)用使航海行程效率提高了25％。 隨著汽車的發(fā)明，則需要更精確且運(yùn)行平穩(wěn)的齒輪。雖然早在1916年就有能力制造直角交錯(cuò)軸雙曲面齒輪，但直到1926年才開(kāi)始用Packard汽車，它的應(yīng)用能簡(jiǎn)短驅(qū)動(dòng)軸并減少了所占空間。到1937年幾乎所有的汽車都用直角交錯(cuò)軸雙曲面齒輪為后橋。1930年左右研制了含抗磨損添加劑的特殊潤(rùn)滑劑并用于直角交錯(cuò)軸雙曲面齒輪。1931年，美國(guó)機(jī)械工程師學(xué)會(huì)齒輪機(jī)構(gòu)研究委員會(huì)主席Earle Buckingham發(fā)有一篇關(guān)于輪齒動(dòng)態(tài)承載方面的具有里程碑意義的技術(shù)報(bào)告。這使人們更好地了解為什么轉(zhuǎn)動(dòng)較快地齒輪有時(shí)承載能力不如轉(zhuǎn)動(dòng)較慢地齒輪。 二十世紀(jì)20至30年代期間研制了制造齒輪的高強(qiáng)度合金剛；30年代又將滲氮及表面硬化技術(shù)用以增加齒輪傳動(dòng)機(jī)構(gòu)的表面強(qiáng)度；1950年應(yīng)用感應(yīng)淬火技術(shù)；1960年應(yīng)用了由真空熔化工藝所煉的高度清潔鋼材，這對(duì)于延長(zhǎng)齒輪的使用壽命是很有效的。 自本世紀(jì)六十年代初期以來(lái)，發(fā)電用的工業(yè)燃?xì)廨啓C(jī)被廣泛應(yīng)用。由于成功地采用了行星齒輪機(jī)構(gòu)，其功率達(dá)1000－14，000馬力，節(jié)線速度為50－100m/s。在兩次檢修期間，齒輪組必須可靠工作10，000至30，000小時(shí)。 1976年生產(chǎn)的用于驅(qū)動(dòng)壓縮機(jī)試驗(yàn)臺(tái)的傘齒輪在功率為2984KW（4000馬力），速度為200m/s(40,000ft/min)的工作環(huán)境下成功地運(yùn)行了235小時(shí)。所有指標(biāo)表明，如果需要，這些齒輪均可作為工業(yè)應(yīng)用。作為商用的弧齒螺旋傘齒輪合理的最大節(jié)線速度為60m/s(12000ft/min)。 已經(jīng)提出了齒輪機(jī)構(gòu)設(shè)計(jì)的新方法，所設(shè)計(jì)的質(zhì)量輕，速度高，承載能力強(qiáng)的齒輪已用于航空工業(yè)。齒輪傳動(dòng)機(jī)構(gòu)的強(qiáng)度，動(dòng)載，以及諧振頻率等問(wèn)題現(xiàn)在可用有限元分析，對(duì)模型進(jìn)行回聲試驗(yàn)，阻壓試驗(yàn)等技術(shù)來(lái)解決