【正文】 所有機構(gòu)中均采用滾動軸承。近年來趨向用制度性能良好的電動液壓推桿和電磁液壓推桿式制動器來取代上述幾種制動器。它設(shè)置在與小車軌道垂直的小車臺邊緣上。當?shù)蹉^組上升到允許的最高位置時，固定在吊鉤組上的擋板就將墜重抬起，使懸掛它的鋼繩松弛，此時，杠桿在另一端重塊作用下轉(zhuǎn)動約30℃，因此使開關(guān)盒內(nèi)的電路觸點斷開，起升機構(gòu)電動機斷電停止，吊鉤組不再上升。無論哪一種限位開關(guān)，吊鉤組上升的極限位置應(yīng)該與卷筒或定滑輪之間保持一定距離。常用小車緩沖器安裝在小車架上，而擋鐵則安裝在橋架兩根主梁的兩端；也有將緩沖器和擋鐵的位置反過來安裝的。廠房內(nèi)設(shè)兩臺250/50/10t橋機，吊裝定子及轉(zhuǎn)子時，兩臺橋機掛500t平衡梁，利用平衡梁與轉(zhuǎn)子連接起吊轉(zhuǎn)子。起升機構(gòu)設(shè)有重錘式和雙重限位開關(guān)。該結(jié)構(gòu)也便于車輪的裝拆。 a——起動平均加速度，m/s2。m； Ma—機構(gòu)制動時需制動的慣性力矩； Mjmin—有利于機構(gòu)制動時的最小阻力矩；Ma= + = + =式中：Zz—制動器數(shù)量； nm—電動機額定轉(zhuǎn)速， r/min。m； nt聯(lián)軸器的選用安全系數(shù)， 取nt=； Φ8剛性振動系數(shù)， 取Φ8=~； Mi被連接軸上的扭矩， Nm； V起重機或小車碰撞時的碰撞計算速度， m/min。m材料：大小齒輪采用的材料為40Cr，并經(jīng)過調(diào)質(zhì)和表面淬火，硬度為40~55HRC閉式傳動，精度7級，初選材料螺旋角β=12o使用期6年，每年工作300天，每天8小時。m材料：大小齒輪采用的材料為40Cr，并經(jīng)過調(diào)質(zhì)和表面淬火，硬度為48—55HRC閉式傳動，精度7級，初選材料螺旋角β=12o，使用期6年，每年工作300天，每天8小時。大齒輪 腹板式—頂圓直徑da≤500mm的齒輪可以是鍛造的或鑄造的，通常采用腹板式結(jié)構(gòu)。鑄鐵具有良好的鑄造性能和切削加工性能，成本低。游標尺安裝位置不能太低，以避免油溢出游標尺座孔。兩定位銷之間的間距越遠越可靠，因此，通常將其設(shè)置在箱體凸緣的對角處，并應(yīng)作非對稱布置。本設(shè)計還完成了減速器中的齒輪的結(jié)構(gòu)設(shè)計，以及減速器箱體的結(jié)構(gòu)設(shè)計。第五章 外文翻譯Tower CraneBoom mounted on the upper part of the rotation of the tall tower crane. Operating a large space, mainly used for housing construction materials in the vertical and horizontal transportation and installation of building ponents. From the metal structure, working bodies and the electrical system consists of three parts. Metal structure including the tower moving arms and base and so on. The work of organizations including lifting,luffing, slewing and walking four parts. Electrical systems including motors, controllers, power distribution cabinets, connection lines, signals and lighting devices.Short tower crane tower crane, also known as tower crane, originated in Western Europe. According to records, the first tower crane used in construction related to the patent granted in1900. Emerged in 1905 with a fixed jib tower crane, and in 1923 produced the prototype of modern tower crane, in the same year the first relatively plete modern tower crane. 1930, when Germany began mass production of tower cranes, and used for building construction. In1941, the tower crane industry standard DIN8770 published in Germany. The standard provides for crane set (t) and amplitude (m) of the product (tm) together to retorque, said the tower crane lifting capacity.China tower crane industry in the 20th century, 50 years started, as opposed to the Western European countries due to weakness in the construction industry caused by the tower crane industry in recession, Shanghai Poch Drive System Co., Ltd. tower crane industry in China is in a rapid period of development .From the tower crane in terms of technological development, while an endless stream of new products, new products in the production efficiency, easy operation, and maintenance easier and more reliable operation in the increase in the tower crane, but there is no fundamental change in the technology. The tower crane research is towards modular development. The socalled modular, that is, to the tower structure as the core, according to structural and functional characteristics of the shaft broken down into several parts, and on the basis of seriation and general requirements, follow the modulus of the various parts of the system theory and then divided into a number of modules. According to parameters required, choose the appropriate modules were grouped with different performance characteristics of the tower crane technology to meet the specific needs of the construction. The implementation of modular tower crane tower crane production capacity will help to speed up the development progress of Lu, save product development costs, and better for customer service.Slewing tower crane be divided into upper and lower rotary tower crane tower crane two broad categories. In which the carrying capacity of the former than the latter, in many we have seen the construction site is on a rotary festival add up on top of a high tower crane access. According to whether the move is further divided into: walking a line, and fixed. Fixed the fixed tower crane tower do not switch installed in the concrete block foundation, or installed in the form of Xshaped concrete foundation. In the housing construction generally use a fixed characteristics and safety devicesTower crane boom and struts form of subhorizontal type two kinds. For the horizontal boom, the load car runs along the level luffing boom, luffing movement balance, its long boom, but the greater weight boom. Boom for the struttype when the tractor boom luffing mechanism Pitch amplitude, amplitude motion than horizontal steady, but its relatively small weight.In order to ensure the safety of tower crane has a good safety device, such as starting weight, range, height and load torque constraints such devices, as well as the travel limit switches, tower lights, wind instrument, wind cliprail device, Ladders and athletic supporter circle, walkways and railings. Driver39。整個傳動過程比較平穩(wěn)，拆卸方便，維修容易，價格低廉。選擇通氣器類型時應(yīng)考慮通氣器對環(huán)境的適應(yīng)性，其規(guī)格尺寸應(yīng)于減速器大小相適應(yīng)。游標尺上有表示最高級最低油溫的尺線。箱體底座要有一定的寬度和厚度，以保證安裝穩(wěn)定性與剛度。③計算大小齒輪分度圓直徑 d3=== d6===④計算齒寬 b=φdd5==圓整后 B6=100mm B5=105mm驗算 Ft=== ==100N /mm所以滿足齒面接觸疲勞強度和齒根彎曲疲勞強度。③計算大小齒輪分度圓直徑 d3=== d4===④計算齒寬 b=φdd3==圓整后 B3=60mm B4=65mm驗算 Ft=== ==100N /mm所以滿足齒面接觸疲勞強度和齒根彎曲疲勞強度。mT4=9550P4/n4=9550 W=()2 = Nm制動器的制度力矩 Mz=Ma—Mjmin== N G——起重機或小車的運動質(zhì)量，t； a——平均起動加速度，m/s2，； μ0Pi== K0(Ga+Wj)=（315+）= ≥，故打滑實驗通過。第三章起重機小車運行機構(gòu)的計算一．跨度、額定起重量 （1）跨度、額定起重量 橋機跨度 L=20m 主鉤額定起重量 Gz=250t 副鉤額定起重量 Gf=50t 電動葫蘆額定起重量 Gd=10t (2)起升高度 主鉤起升高度 26m 副鉤起升高度 32m 電動葫蘆起升高度 40m