外文翻譯--自移式液壓支架-液壓系統(tǒng)-wenkub.com
2025-05-07 05:59 本頁面
【正文】 有些頂梁是一個(gè)整體，而有些頂梁則是由通過鉸接并在鉸接處安裝一液壓千斤頂?shù)膬刹糠纸M成的。所以，支撐掩護(hù)式液壓支架具有以上兩者所具有的優(yōu)點(diǎn)。另外，當(dāng)降低液壓支柱時(shí)，未支護(hù)面積將會減少。 圓弧形：在圓弧形掩護(hù)式液壓支架中，掩護(hù)梁和底座之間通 過單一的鉸接連接。隨著掩護(hù)式液壓支架立柱的升起和下降，選擇好雙紐線桿的尺寸，就可以使頂梁前端近乎垂直的作上升和下降運(yùn)動，這樣就可以保持頂梁前端與煤壁之間未支撐的距離為一常量，這種特性對很好控制頂板來說是廣泛考慮的最合乎要求的。 頂梁端部的運(yùn)動軌跡的形式 這是公認(rèn)的最普遍的對掩護(hù)是液壓支架的分類方法。由于只有液壓立柱的垂直分量 起支護(hù)頂板的作用，掩護(hù)式液壓支架的承載能力隨著采煤高度的變化而變化。因此，掩護(hù)式液壓支架的工作面一般都比較清潔。當(dāng)部分頂板已經(jīng)完全懸掛在采空區(qū)時(shí)，需要引導(dǎo)其塌落，這時(shí)垛式液壓支架就可以提供一條通向采空區(qū)的通道。 在大多數(shù)垛式支架中，液壓支柱與頂梁和液壓支柱與底座之間都采用鉸接式連接。六柱式垛式支架是為薄煤層設(shè)計(jì)的，兩個(gè)支柱在前，四個(gè)在后，中間是人行走的通道。在這兩種情況下， 兩垛式支架之間將有一個(gè)很大的空間，并在其中部安裝雙作用立柱，這種立柱將把刮板輸送機(jī)和垛式液壓支架作為一個(gè)整體進(jìn)行推移，這就是垛式液壓支架與節(jié)式液壓支架的不同。兩塊頂板下有相當(dāng)大的未覆蓋區(qū)域，這段區(qū)域允許碎石落入。當(dāng)?shù)竭_(dá)新位置以后，次要支柱支撐頂板，主要 支柱降低并且由缸筒拉動前進(jìn)。先移動的是次要裝置，后移動的是主要裝置。它包括一前一后垂直安裝的支柱，支 柱連接在單一或分割的頂梁的頂端。 對于即時(shí)支護(hù)方式，液壓支架在截煤機(jī)過去之后立即跟隨刮板輸送機(jī)前進(jìn)，液壓支架前面的頂板有足夠的長度來支護(hù)采過和將要采的頂板部分。 對于標(biāo)準(zhǔn)支護(hù)方式，采煤機(jī)作切割或分段運(yùn)動，工作面輸送機(jī)由裝在液壓支架上的推移千斤頂推動前進(jìn)。另外，液壓支柱的 安裝方式也很重要，例如，立柱垂直安裝在底座和有掩護(hù)梁的頂梁之間，此時(shí)對頂板具有最小的支護(hù)效率。 這里使用一個(gè)簡化的液壓支架的分類。因此，從技術(shù)和經(jīng)濟(jì)兩方面的觀點(diǎn)看，液壓支架是長壁采煤工作面設(shè)備中十分重要的一部分。 i. e. , pushing the conveyor first, and then advancing the support. With the IFS system, the support units is advanced to the conveyor immediately after the cutting machine has passed, and the forward canopy of the support units is long enough to the support both the recently and newly exposed roof sections. After the supports have been advanced, the conveyor is pushed over. FRAME The frame support is an extension of the single hydraulic props conventionally used underground. Thus it is the first type developed in modern selfadvancing hydraulic powered supports. It involves setting up two hydraulic props or legs vertically in tandem that are connected at the top by a single or two segmented canopies. The two segmented canopies can be hingejointed at any point between the legs or in front of the front leg. The base of the two hydraulic legs may be a circular steel shoe welded at bottom of each leg or solid base connecting both legs. Generally, a frame support consists of two or three sets of hydraulic legs. The set moving first is the secondary set, the set moving later is the primary set. There is a doubleacting ram installed between each set. The piston of the ram is connected to the secondary set and the cylinder to the primary set. During support advance, the primary set is set against the roof while the secondary set is lowered and pushed forward by the piston. Having reached the new position, the secondary set is against the roof while the primary set is lowered and pulled forward by the cylinder. The distance of each advance ranges from 20 to 36 in.( ~ ) The frame support is very simple, but more flexible or less stable structurally. There are considerable uncovered spaces between the two pieces of canopy which allows broken roof rock to fall through. Consequently, the frame support is not su
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