【正文】 nto the cab of a crane.Imagine that a mercial airline pilot had the same training as a certified crane operator. How would you feel the next time you decided to fly? In California, it takes more hours of training to wield a pair of scissors in a hair salon than to operate potentially dangerous lifting machinery. How does this make sense?Riggers and signal persons also need standard training and testing to ensure safety under the hook. Employers usually allow any craft to signal a crane on a jobsite, despite best practices that require only qualified people do so. How is it then that uncertified and untrained people are allowed to signal and rig under the hook of a licensed or certified operator?Tower cranes are particularly risky as urban sites bee more congested, and the risk of a catastrophic event is very high during climbing operations. Yet most towercrane climbing crews are trained in a nontraditional manner, via secondhand knowledge that has been passed down over time. The problem with this type of handmedown knowledge is that it changes over the years, leaving out smallbutimportant details along the way. This osmosis of knowledge leads crews to develop their own tricks for climbing cranes, often forsaking basic safety in an attempt to save time and energy.In many cases, there are no safety devices or alarms to warn of a serious problem. Climbing crews are subjected to pressures that affect safetycritical decisionmaking. It is not unmon for climbs to continue with damaged or leaking hydraulic systems, outofadjustment or jammed guide rollers, often working in the dark and for extended hours. This MacGyver method of climbing, where every jump bees a new adventure, should not be the norm.Climbingframe designs vary among manufacturers, but the operational steps are similar in principle. The climbing process is relatively straightforward, with a mixture of physical work and technical procedure. It is not plex。 as we know it today. As they had actually designed the Motocrane, both knew it inside out and were pleased to pass on this knowledge.In response to the longstanding problems,in which the swinging angle of the hoisted load and the velocity of swinging angle is difficult to measure in engineering practice,a state observer is designed by the use of information about the crane trolley39。最近塔式起重機倒塌在一個繁忙的紐約市建筑地盤應(yīng)敲響警鐘，提醒我們問題的存在，并加強我們目前安全的做法。雇主通常允許任何工人發(fā)信號指揮起重機上工地 ，盡管最佳做法是需要合格的人這樣做。在黑暗中工作和延長工作時間是時有發(fā)生的。視察員同樣也也須有具體的技術(shù)培訓。然。這就是為什么業(yè)界需要規(guī)范的培訓，測試和監(jiān)督，其中包括一個實際的評估能力。攀登人員容易遭受到影響安全性至關(guān)重要的決策所帶來的壓力。你會如何感覺，下一次你決定要坐飛機？在加利福尼亞州，掌握一對剪刀在頭發(fā)沙龍比操作有潛在危險的起重機械需要更多的時間訓練。據(jù)國內(nèi)有關(guān)部門統(tǒng)計資料表明，%。 series. This consisted of three cranes which, for the first time in history, were mounted on chassis built by the crane manufacturer itselfi The smallest crane, the MC2, could lift tonnes, the MC2 tonnes and the MC3 tonnes. These cranes were delivered to the army by the thousand, and were also mounted on portals for use as harbour cranes (the MC4 model). The war had, of course, taken its toll on the number of ablebodied men available to work in the crane industry and there was a serious shortage of good crane drivers. At Thew, newers were taught crane operations over a twoday course presented by A C Burch, an experienced mechanic and graduate of the Naval Academy, and L K Jenkins. These two gentlemen were probably the originators of 39。s increasingly petitive construction market, to meet the construction needs of many construction panies have bought the tower crane. With the tower crane at the construction site of the widely used by the tower crane accident also caused more and more to people39。在整個設(shè)計中由于時間倉促，難免出現(xiàn)不少錯誤，望各位老師在設(shè)計過程中，第一階段，我們精心收集整理各種資料，提高了對新知識的自學能力，對資料的搜集整理能力。由于大車運行速度大于80m/min，采用杠桿式限位開關(guān)不能提供可靠的保證，故采用無觸點運行限位系統(tǒng)：光電裝置來保證。11 安全裝置的選擇說明電動雙梁橋式起重機有相應(yīng)的電氣保護裝置以外，還有其他保護裝置。選用后進行強度較核。本設(shè)計選用了軌道安裝在主梁的正中形式。 根據(jù)結(jié)構(gòu)尺寸和 查手冊，選用LM8型梅花彈性聯(lián)軸器，其 ；轉(zhuǎn)動慣量 滿足要求標注：LM8聯(lián)軸器GB/T5272—2002器連接處聯(lián)軸器選擇：浮動軸尺寸：d=50mm減速軸高速軸尺寸：d=38mm，L=80 mm選LM7型梅花彈性聯(lián)軸器； 則有： ；轉(zhuǎn)動慣量： 滿足要求標注：LM7聯(lián)軸器 GB/T 5272—2002（2）低速軸聯(lián)軸器選擇選用聯(lián)軸器公式：=式中：—減速器傳動比；=25—機構(gòu)傳動效率；=：減速器低速端尺寸：d=80mm。 選用合理聯(lián)軸器標注為：LM12聯(lián)軸器MT12aGB/T 5272— 2002（2）減速器與浮動軸的連接處聯(lián)軸器浮動軸端尺寸：d=95mm減速器輸入軸：d=90mm L=170mm制動輪直徑：D=500 mm根據(jù)以上結(jié)構(gòu)尺寸和T=5328m。 e=. 螺栓預(yù)緊力計算 因選壓板槽為半圓形，故：. 螺栓強度驗算 = =110MPa校驗通過式中：Z—固定鋼絲繩用的螺母數(shù)，取Z=4 d—螺栓螺紋的內(nèi)徑；d= —墊圈與鋼絲繩壓板之間的摩擦系數(shù)，取= t—作用力臂；根據(jù)壓板得t=—螺栓許用拉應(yīng)力，==—螺栓屈服強度；因螺栓材料為Q235；查手冊得：=206Mpa. 壓板的選取 查手冊：選取序號為6的壓板，標準槽標注：壓板6GB/T5975—19868 起升機構(gòu)的設(shè)計 工作級別為M6。其中利用等級為T4,載荷狀況L2 3 吊鉤組的選擇計算 機構(gòu)工作級別:M6, 采用雙聯(lián)滑輪組,倍率: m=4起升質(zhì)量: = 18 t 起升載荷: 起升速度: ~ 初取 吊鉤采用倍率m=4的雙聯(lián)滑輪組,故采用長形吊鉤組吊鉤用普通的短吊鉤 選用吊鉤斷面為梯形的吊鉤,材料為20鋼,機加工前熱處理,硬度小于或等于156HBS 單鉤 D 即D= mm 則由公式 得，h=150 (因為吊鉤斷面為梯形，故h=D)Q額 ：額定起重量（噸） 1—2和3—4斷面為危險斷面，通常垂直斷面3—4取與水平斷面1—2相同的斷面，而最大拉應(yīng)力約為1—2斷面的50% ，故只驗算1—2面。一個工作循環(huán)一般包括上料、運送、卸料及回到原位的過程，即取物裝置從取物地點由起升機構(gòu)把物料提起，由運行機構(gòu)把物料移位，然后物料在指定地點下放，接著進行相反動作，使取物裝置回到原處，以便進行下一次工作循環(huán)。 小車 小車由起升機構(gòu)，小車運行機構(gòu)，小車架和保護裝置等組成。它通常用來搬運物品，也可用于設(shè)備的安裝與檢修等用途。在起重機控制方面，起升機構(gòu)用主令控制器和磁力控制屏來實現(xiàn)控制，大、小車運行機構(gòu)用凸輪控制器直接控制。指導(dǎo)教師： 2010年 6 月 5 日答辯簡要情況及評語答辯小組： 年 月 日答辯委員會意見答辯委員會主任： 年 月 日目錄中文摘要 ……………………………………………………………………… Ⅰ英文摘要 ……………………………………………………………………… Ⅰ1緒論 …………………………………………………………………………… 1 ………………………………………………………… 1 ……………………………………… 1 ………………………………………………………………… 1 ………………………………………………………………… 1 ……………………………………………… 1 …………………………………………… 12設(shè)計任務(wù)及參數(shù) ……………………………………………………………… 2 …………………………………………………………… 2 ………………………………………………… 23吊鉤組的設(shè)計計算 …………………………………………………………… 2 ………………………………………………………………… 2 ………………………………………………………………… 24滑輪組的設(shè)計計算 …………………………………………………………… 65鋼絲繩的選擇 ……………………………………………………………… 86卷筒的設(shè)計計算……………………………………………………………… 97鋼絲繩在卷筒上的固定……………………………………………………… 118起升機構(gòu)的設(shè)計計算………………………………………………………… 12 ……………………………………………………………… 12…………………………………………………………… 129小車運行機構(gòu)的設(shè)計計算…………………………………………