freepeople性欧美熟妇, 色戒完整版无删减158分钟hd, 无码精品国产vα在线观看DVD, 丰满少妇伦精品无码专区在线观看,艾栗栗与纹身男宾馆3p50分钟,国产AV片在线观看,黑人与美女高潮,18岁女RAPPERDISSSUBS,国产手机在机看影片

正文內(nèi)容

外文翻譯--自移式液壓支架-液壓系統(tǒng)-免費(fèi)閱讀

2025-06-21 05:59 上一頁面

下一頁面
  

【正文】 常規(guī)的四柱或六柱支撐掩護(hù)式液壓支架所有的立 柱都是垂直安裝、互相平行的。這就是大多數(shù)用戶所考慮的,圓弧型式掩護(hù)式液壓支架最不合適的地方。 雙紐線形:這是最常用的一種 類型。由于頂板、掩護(hù)梁和底座是相互連接的,所以掩護(hù)式液壓支架可以更好的抵抗橫向力,而不需要使立柱彎曲。在金屬框上方的立柱周圍安裝復(fù)位裝置。 和節(jié)式液壓支架一樣,所有的液壓立柱垂直安裝在底座和頂板之間。(即 到 米)。兩根液壓支柱的底部是焊接在每個(gè)支柱末端的一只金屬環(huán)形底靴或者固體底座連接兩根支柱。對(duì)于滯后式支護(hù)方式,支架不可能靠近輸送機(jī),因?yàn)橛幸粋€(gè)裝置自動(dòng)的使支架前端與輸送機(jī)保持一定的距離。在其中,有兩個(gè)因素是最重要的: (1) 是否使用掩護(hù)梁 —如果使用了掩護(hù)梁,那么液壓支架屬于掩護(hù)式液壓支架,否則,支架就屬于節(jié)式支架或者垛式支架。因此正確的選擇和應(yīng)用液壓支架是長(zhǎng)壁工作面采煤成功的先決條件。 for example, a vertical installation between the base and the canopy has the caving shield has the least efficiency in supporting the roof. Based on this concept, there are four types of powered support, that is, the frame, chock, shield and chock shield, in order of evolution of their development. However, it must be noted that the trend of development in each type is such that it bees less distinguishable in terms of application. The four types of roof supports can be obtained for either longwall retreating or advancing systems, and they are available in standard, onewebback, and immediate forward support (IFS) versions. With the standard system, the wining machine takes a cut or a slice, and the armored face conveyor is pushed over by the hydraulic rams that are fixed to the support units. The support units then are advanced sequentially to the conveyor. With the onewebback system, a support is set back from the conveyor by a device that automatically keeps the leading edge of the support at a fix distance from the conveyor. This allows easy access though the face and employs the standard method of advancing。但是,到現(xiàn)在始終沒有一個(gè)統(tǒng)一的分類系統(tǒng)。 這四種類型的液壓支架不僅可以用于后退式長(zhǎng)壁回采工作面和前進(jìn)式開采工作面,還可以用于標(biāo)準(zhǔn)方式、滯后支護(hù)方式和即時(shí)支護(hù)方式。它是現(xiàn)代自推進(jìn)式液壓支架發(fā)展的第一個(gè)類型。支架前進(jìn)過程中,當(dāng)次要支柱降低并通過活塞推動(dòng)向前移動(dòng)時(shí),主要支柱使頂梁平衡。 垛式液壓支架 在垛式液壓支架中,頂梁是一個(gè)堅(jiān)固的整體結(jié)構(gòu),而底座則可能是堅(jiān)固的整體結(jié)構(gòu)或者兩個(gè)獨(dú)立的部分,它們用金屬桿在其前端或尾部連接起來。擋矸簾由一些矩形的金屬片組成,這 些金屬片的兩端水平連接。掩護(hù)式支架可以完全封鎖采空區(qū),防止巖石碎片落入支架的工作面。頂梁端部的運(yùn) 動(dòng)軌跡,液壓立柱的定位于定向,液壓立柱的數(shù)目,頂梁的幾何形狀,以及其他的可以任意選擇的設(shè)計(jì)方法和理念都可以用專業(yè)術(shù)語詳細(xì)的說明。如超出這個(gè)限制,頂梁前端將會(huì)迅速的遠(yuǎn)離采煤線,從而產(chǎn)生一個(gè)很大的未支護(hù)面積。 支撐掩 護(hù)式液壓支架 支撐掩護(hù)式液壓支架結(jié)合了垛式液壓支架和掩護(hù)式液壓支架的特點(diǎn)。支撐掩護(hù)式液壓支架具有最高的支護(hù)效率,因此適用于堅(jiān)硬頂板。 橢圓形:在橢圓形掩護(hù)式液壓支架中,掩護(hù)梁和底座采用這種方式連接,當(dāng)液壓支架的立柱作上升和下降運(yùn)動(dòng)時(shí),支架頂板的前端沿橢圓形軌跡運(yùn)動(dòng)。當(dāng)采煤高度有明顯限制時(shí),頂梁前端垂直運(yùn)動(dòng)。 掩護(hù)是液壓支架有很多種類。 掩護(hù)式液壓支架 掩護(hù)式液壓支架是在七十年代新出現(xiàn)的一種液壓支架,它的特點(diǎn)是在底座和頂梁尾端增加了掩護(hù)梁。對(duì)于六柱式支架,頂梁在通道的上方鉸接。因此,節(jié)式液壓支架不適合較弱頂板。每根支柱之間有雙作用液壓缸。在液壓支架前進(jìn)以后,刮板輸送機(jī)也被推移前進(jìn)。 基于這個(gè)概念,按照液壓支架發(fā)展進(jìn)化的順序,把液壓支架分為四類,即:節(jié)式支架,垛式支架,掩護(hù)式支架和支撐掩護(hù)式支架。 現(xiàn)代液壓支架的應(yīng)用可以追溯到上個(gè)世紀(jì) 50 年代早期。 英文原文 Selfadvancing hydraulic powered support Modern longwall mining employs hydraulic powered supports at the face area. The supports not only holds up the roof, pushes the face chain conveyor, and advances itself, but also provides a safe environment for all associated mining activities. Therefore its successful selection and application are the prerequisite for successful longwall mining. Furthermore, due to the
點(diǎn)擊復(fù)制文檔內(nèi)容
畢業(yè)設(shè)計(jì)相關(guān)推薦
文庫(kù)吧 www.dybbs8.com
備案圖鄂ICP備17016276號(hào)-1