【正文】 ars that the English abbot of ’s monastery, born Richard of Wallingford, in . 1330, reinvented the epicyclic gearing concept. He applied it to an astronomical clock, which he began to build at that time and which was pleted after his death.A mechanical clock of a slightly later period was conceived by Giovanni de Dondi(13481364). 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 geartooth 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 remended the involute curve for gear teeth (ca. 1694). Leonard Euler worked out the law of conjugate action(). Gears deigned according to this law have a steady speed ratio.Since the industrial revolution in midnineteenth century, the art of gearing blossomed, and gear designs steadily became based on more scientific principles. In 1893 Wilfred Lewis published a formula for puting stress in gear teeth. This formula is in wide use today in gear design. In 1899 George , the founder of five gear manufacturing panies, 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 oceangoing vessels. This application achieved an overall increase in efficiency of 25 percent in sea travel.The need for more accurate and quietrunning 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 hypoidgeared 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 mittee on gearing, published a milestone report on geartooth dynamic loading. This led to a better understanding of why fasterrunning gears sometimes could not carry as much load as slowerrunning gears.Highstrength alloy steels for gearing were developed during the 1920s and 1930s . Nitriding and casehardening 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. Pitchline 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 pressor 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 pitchline velocity for mercial spiralbevel 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 finiteelement analysis, siren and impulse testing for mode shapes, and application of damping treatments where required.齒 輪李洪光（譯） 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。參考文獻(xiàn)[1]孫恒，陳作模. 機(jī)械原理 [M].北京：高等教育出版社，2001[2]濮良貴，[M].北京：高等教育出版社，2001[3]王伯惠，[M].北京：人民交通出版社，1999[4]吳宗澤，羅圣國. 機(jī)械設(shè)計(jì)課程設(shè)計(jì)[M].北京：高等教育出版社，1999[5]鄒慧君. 機(jī)械原理課程設(shè)計(jì)手冊(cè)[M].北京：高等教育出版社， 1998[6] 范欽珊. 材料力學(xué)[M].北京：高等教育出版社，[7]《現(xiàn)代機(jī)械傳動(dòng)手冊(cè)》[M].北京：機(jī)械工業(yè)出版社，2002[8](第5卷) [M].北京：化學(xué)工業(yè)出版社，2002[9]劉古岷，王渝，[M].北京：機(jī)械工業(yè)出版社，2001[10] 成大先. 機(jī)械設(shè)計(jì)圖冊(cè)(第5卷)[M].北京：化學(xué)工業(yè)出版社，2000[11]《機(jī)械工程手冊(cè)》(第11卷機(jī)械產(chǎn)品(一)) [M]. 北京：機(jī)械工業(yè)出版社，1982 [12][M].北京：經(jīng)濟(jì)日?qǐng)?bào)出版社，1991[13]日本機(jī)械學(xué)會(huì). 機(jī)械技術(shù)手冊(cè)[M].北京：機(jī)械工業(yè)出版社，1975[14]《機(jī)械工程手冊(cè)》(專用機(jī)械卷(二))[M]：北京：機(jī)械工業(yè)出版社，1997[15][M].北京：科學(xué)出版社，1991[16][M].北京：機(jī)械工業(yè)出版社，1996[17]卜炎. 機(jī)械傳動(dòng)裝置設(shè)計(jì)手冊(cè)[M]. 北京：機(jī)械工業(yè)出版社，1997[18]吳宗澤、[M].北京：化學(xué)工業(yè)出版社，1999[19] 《齒輪手冊(cè)》編委會(huì). 齒輪手冊(cè)[M].北京：機(jī)械工業(yè)出版社，2001[20][M].北京：中國標(biāo)準(zhǔn)出版社，2001[21][M].北京：機(jī)械工業(yè)出版社，1985致謝 本次畢業(yè)設(shè)計(jì)是在匡建新老師的精心指導(dǎo)和幫助下以及同學(xué)們的幫助下共同完成的。其回轉(zhuǎn)運(yùn)動(dòng)由傳動(dòng)齒輪來提供，而軸向沖擊運(yùn)動(dòng)，我參考流體推桿高能沖擊錘的工作原理后，采用了沖擊汽缸來進(jìn)行軸向沖擊運(yùn)動(dòng)。(7)鉆進(jìn)過程中，每班工作人員應(yīng)堅(jiān)守崗位，司機(jī)、記錄員、技術(shù)人員要隨時(shí)觀察各種情況，如鉆機(jī)工作是否正常，空壓機(jī)、供漿量及排漿量是否正常等等，發(fā)現(xiàn)異常應(yīng)及時(shí)處理。(3)開始鉆進(jìn)，或通過軟硬層交界處，為保持鉆桿垂直，應(yīng)采用慢進(jìn)。水位差也不宜過大，以防反滲流。粘土層中，為了克服泥包鉆頭，應(yīng)采用高轉(zhuǎn)速，鉆頭外緣的線速度可大于3～4m/s；在砂層和巖石層中鉆進(jìn)，則應(yīng)采用低轉(zhuǎn)速。泥漿一般有純硼潤土泥漿與硼潤土黃泥混合泥漿。氣舉反循環(huán)排渣的工作原理。泥漿沉淀后，清泥漿重新被打入孔中。軸在工作是既承受彎矩又承受扭矩，則應(yīng)按彎扭合成強(qiáng)度條件進(jìn)行計(jì)算。由于軸上軸向力變化較大，鉆筒上蓋出口用兩個(gè)角接觸球軸承來滿足其要求，用軸端蓋來定其軸向間隙和受力。由資料得，定位軸肩的高度h=(～)d，其中d為與零件相配處軸徑尺寸。由于鉆具的外形特點(diǎn)為圓筒形，這樣就存在三種裝配方案：一種是零件在主軸從上到下進(jìn)行裝配；一種是零件在主軸上從下到上進(jìn)行裝配；還有一種是零件從主軸兩端進(jìn)行裝配。軸的材料主要是碳鋼和合金鋼。這樣可以提高鉆進(jìn)速度。其主要參數(shù)的確定必須考慮到，巖石的堅(jiān)硬性，孔的直徑，深度及方向是設(shè)計(jì)鉆機(jī)的主要依據(jù)，它們決定鉆機(jī)的主要結(jié)構(gòu)和機(jī)重，同時(shí)又影響其它參數(shù)的選擇。對(duì)不同性質(zhì)的巖石使用不同類型的鉆頭，是提高破巖效率的重要條件。牙輪分兩種型式。破碎巖石的沖擊力要求大于900才能破碎巖石。在每個(gè)行星輪的內(nèi)孔中，安裝兩個(gè)滾動(dòng)軸承來支撐。(3) 安裝條件：所以，滿足安裝條件。據(jù)表查得：=23,=34,=91,=5,=齒輪材料和熱處理選擇：中心輪a、內(nèi)齒圈b和行星輪c均采用20CrMnTi滲碳淬火，回火，齒面硬度56～62HRC,據(jù)圖612和圖627（均為《行星齒輪傳動(dòng)設(shè)計(jì)》，后同），取=1400和=340，則加工精度為6級(jí)。：根據(jù)本設(shè)