刮板輸送機(jī)的常見故障及對(duì)策

1、刮板輸送機(jī)的常見故障及對(duì)策摘要：刮板輸送機(jī)是煤礦常用的機(jī)械,它的正常使用與安全運(yùn)行對(duì)于提高煤礦的生產(chǎn)效率和經(jīng)濟(jì)效益具有重要作用。刮板輸送機(jī)在運(yùn)行過程中經(jīng)常會(huì)出現(xiàn)斷鏈，磨損失效，上竄下滑等故障。這些故障嚴(yán)重影響了輸送機(jī)的正常運(yùn)轉(zhuǎn)，因此必須采取相應(yīng)的措施來進(jìn)行預(yù)防和維修。關(guān)鍵詞：刮板輸送機(jī)；斷鏈；磨損失效；上竄下滑。1 刮板輸送機(jī)斷鏈原因分析(1)隨著采煤機(jī)械化的提高,刮板輸送機(jī)在使用過程中,基本上都是滿負(fù)荷運(yùn)載。時(shí)間久了兩鏈輪磨損嚴(yán)重磨損程度不一樣或兩鏈輪不對(duì)稱導(dǎo)致兩鏈?zhǔn)芰Σ黄胶?極易造成連接環(huán)被拉斷。(2)刮板鏈在運(yùn)行中突然被煤炭中的剛性物卡住,或在溜槽對(duì)口處錯(cuò)位,容易掛住刮板或連接環(huán),此時(shí)會(huì)

2、對(duì)刮板或鏈環(huán)產(chǎn)生很大的沖擊力,致使斷鏈。(3)刮板鏈過緊,在刮板輸送機(jī)運(yùn)行中不但增大了刮板鏈的初張力,也使刮板鏈磨損加劇,而且當(dāng)刮板鏈被卡住,沒有緩沖的余地,增大鏈環(huán)和刮板鏈的張力負(fù)荷,也容易造成斷鏈。刮板鏈過松或者兩根鏈條長(zhǎng)短不一,導(dǎo)致刮板不平衡運(yùn)行,在鏈輪處刮板鏈易發(fā)生跳牙,使連接環(huán)受到鏈輪牙齒的沖擊,造成鏈環(huán)變形、斷裂和刮板彎曲。(4)刮板輸送機(jī)過載拉煤,或在超載情況下突然停機(jī)后沒有清空溜槽上的煤炭,再次啟動(dòng)時(shí)增大了刮板鏈承受的初張力,特別是刮板鏈磨損到一定的程度后容易斷鏈。(5)刮板鏈嚴(yán)重磨損,強(qiáng)度降低,受沖擊載菏的反復(fù)作用造成刮板鏈疲勞破壞,節(jié)距增大,新舊兩條刮板鏈的鏈環(huán)節(jié)距不一樣,

3、使全部負(fù)荷均集中在一條鏈條上,以致斷裂。(6)連接環(huán)無螺栓或在運(yùn)行中螺栓丟失,造成連接環(huán)只有一側(cè)受力,連接環(huán)容易折斷造成斷鏈。鏈環(huán)被井下水腐蝕,產(chǎn)生銹疤和脫皮,斷面縮小,強(qiáng)度降低也容易造成斷鏈。(7)工作面底板不平,工作面不直,溜槽底部浮煤多造成刮板輸送機(jī)鏈條受力不均和阻力增大,容易發(fā)生斷鏈。2采取的措施由于以上原因造成刮板輸送機(jī)斷鏈,都是在實(shí)際工作中經(jīng)常遇到的。為了使刮板輸送機(jī)正常安全的運(yùn)轉(zhuǎn),必須加強(qiáng)刮板鏈的檢查和維修并采取相應(yīng)的管理措施。(1)及時(shí)調(diào)整鏈輪,使鏈輪的輪牙對(duì)稱使用;當(dāng)兩鏈輪磨損程度不一致時(shí),更換兩鏈輪使兩鏈?zhǔn)芰ζ胶?兩鏈在運(yùn)轉(zhuǎn)中刮板不斜。(2)堅(jiān)持使用液力偶合器,空載啟動(dòng)以減

4、輕鏈條所受沖擊載荷;溜槽上煤較多時(shí)必須清空溜槽上的煤炭,在啟動(dòng)時(shí)減少鏈條的拉力延長(zhǎng)鏈條的使用壽命。(3)刮板鏈?zhǔn)褂靡粋€(gè)時(shí)期后,將鏈條拆下翻轉(zhuǎn)90°繼續(xù)使用,調(diào)換水平刮板鏈環(huán)與垂直刮板鏈環(huán)的位置,利用改變其磨損部位的辦法延長(zhǎng)鏈條的使用壽命。(4)應(yīng)使用長(zhǎng)度一致,磨損程度差不多的刮板鏈,最好新舊兩條刮板鏈對(duì)稱使用,防止鏈條節(jié)距不一樣。(5)防止刮板鏈過緊、過松,檢查刮板鏈松緊程度最簡(jiǎn)單的方法是:反向點(diǎn)動(dòng)機(jī)頭電動(dòng)機(jī),拉緊底鏈,如果在機(jī)頭出現(xiàn)2個(gè)以上完全松弛的刮板鏈環(huán),需要重新緊刮板鏈。(6)刮板輸送機(jī)在使用過程中,必須平、直,即輸送機(jī)鋪得平,工作面成直線。刮板輸送機(jī)避免急彎;刮板輸送機(jī)溜槽

5、底部不要有浮煤,有浮煤應(yīng)及時(shí)清掉以減少刮板鏈在運(yùn)行中的阻力。3 磨損失效形式及機(jī)理(1)中部槽磨損中部槽是刮板輸送機(jī)的機(jī)身部件。在工作過程中,刮板輸送機(jī)兩邊鏈由機(jī)頭電機(jī)牽引與刮板一起帶著貨載在中部槽中移動(dòng)。中部槽的磨損主要分為貨載(煤及矸石)、刮板和鏈對(duì)中板及槽幫的磨損,以及采煤機(jī)沿中部槽移動(dòng)所造成的槽幫上翼磨損。其中中部槽的槽幫、接頭處舌板磨損往往特別嚴(yán)重,一般中板還能正常工作時(shí),槽幫、舌板就會(huì)磨損失效導(dǎo)致中部槽的過早失效。(2)刮板鏈磨損刮板鏈?zhǔn)褂玫逆湕l,早期為板片鏈和可拆模鍛鏈,現(xiàn)在都用圓環(huán)鏈。刮板鏈的失效形式主要是斷鏈,調(diào)研過程中了解到斷鏈約占刮板輸送機(jī)事故發(fā)生總數(shù)的52.2%,新鏈?zhǔn)?/p>

6、用90 d后斷鏈?zhǔn)鹿拭黠@增多。現(xiàn)場(chǎng)所反映出來的斷鏈?zhǔn)鹿食贁?shù)刮板鏈制造質(zhì)量或操作維護(hù)不良引起的“事故性”斷鏈外,絕大多數(shù)為磨損零部件檢查更換不及時(shí)引起的“自然性”斷鏈。刮板輸送機(jī)工作中,鏈條與溜槽及貨載發(fā)生接觸摩擦,鏈環(huán)與鏈輪在嚙合時(shí)會(huì)產(chǎn)生滑動(dòng)摩擦,鏈環(huán)與鏈環(huán)間相對(duì)運(yùn)動(dòng)引起的摩擦等種種原因都導(dǎo)致鏈環(huán)在工作中極易產(chǎn)生磨損。圖1是鏈環(huán)磨損部位示意圖,主要出現(xiàn)在3個(gè)部位:直邊部分外側(cè),如圖中1剖面線所示,這部分是鏈環(huán)磨損最嚴(yán)重的部分,主要是鏈與溜槽及貨載之間的摩擦所致;圓弧部分外側(cè),如圖中2所示,這部分磨損主要是由于鏈環(huán)在經(jīng)過機(jī)頭鏈輪時(shí)與鏈輪嚙合過程中產(chǎn)生相對(duì)滑動(dòng)摩擦而形成的;圓弧部分內(nèi)側(cè),如圖中3

7、所示,這部分磨損主要是由于鏈環(huán)與鏈環(huán)之間的接觸在直線運(yùn)動(dòng)部分?jǐn)D壓而產(chǎn)生疲勞,并在通過鏈輪時(shí),鏈環(huán)之間的相對(duì)滑動(dòng)摩擦與擠壓而磨損。鏈環(huán)的磨損直接導(dǎo)致鏈環(huán)直徑減小,強(qiáng)度降低,如更換不及時(shí)將會(huì)發(fā)生斷裂。圖1圓環(huán)鏈磨損部位Fig.1Wear parts of chain據(jù)統(tǒng)計(jì),已磨損的刮板鏈傳動(dòng)效率要比正常鏈條降低6%左右,且使平環(huán)肩部磨損加劇,甚至形成“啃肩”現(xiàn)象;同時(shí),平環(huán)與鏈輪輪齒的接觸部位上升,容易造成爬鏈;此外,磨損后的鏈條運(yùn)行中的動(dòng)負(fù)荷較大,易造成機(jī)電事故。據(jù)估計(jì),我國(guó)每年因輸送機(jī)機(jī)電事故而損失的煤炭產(chǎn)量約2 000萬t以上。由于刮板輸送機(jī)工作環(huán)境極為惡劣。鏈條在運(yùn)行過程中除了受滑動(dòng)摩擦的

8、作用外,還要承受很大的靜載荷和動(dòng)載荷,并受礦水的侵蝕,因此,導(dǎo)致自然損壞的因素一般還有動(dòng)載荷、腐蝕及瞬時(shí)沖擊應(yīng)力等。(3)齒輪磨損隨著煤礦機(jī)械化、現(xiàn)代化水平的提高,煤礦機(jī)械的功率日趨增大,導(dǎo)致機(jī)械的輸出扭矩增大,使得煤礦機(jī)械的元部件特別是齒輪的受力增大,但由于受煤礦使用條件和機(jī)器尺寸的限制,傳動(dòng)齒輪的外形尺寸卻沒有多大變化。在井下惡劣環(huán)境中工作的刮板輸送機(jī)傳動(dòng)齒輪,單位齒寬的載荷值很高(達(dá)20kN/cm),齒面磨損非常嚴(yán)重。現(xiàn)場(chǎng)看到部分刮板輸送機(jī)減速器主動(dòng)軸圓弧錐齒輪的輪齒已磨損成刀狀。傳動(dòng)齒輪的失效,嚴(yán)重影響刮板輸送機(jī)的正常工作。通常齒輪傳動(dòng),輪齒齒面間除在節(jié)線位置接觸面為純滾動(dòng)外,其余接觸

9、面間都存在相對(duì)滑動(dòng),這就必然會(huì)產(chǎn)生摩擦,進(jìn)而產(chǎn)生摩擦熱,使齒面的溫度升高。雖然傳動(dòng)齒輪采用齒輪油潤(rùn)滑,但由于機(jī)器運(yùn)轉(zhuǎn)中的振動(dòng),輪齒嚙入與嚙出時(shí)潤(rùn)滑的邊界條件差,邊緣沖擊以及經(jīng)常起動(dòng)、變速和停車等因素的存在,即使有良好的潤(rùn)滑措施,也難以形成良好的潤(rùn)滑狀態(tài),因此齒面間通常處于邊界潤(rùn)滑狀態(tài)。齒輪工作時(shí)承受著巨大載荷,隨著齒面間溫度的升高,潤(rùn)滑膜的破裂,齒面間會(huì)形成大面積的直接接觸,致使磨損加劇,最后發(fā)生膠合失效。除膠合失效外,表面疲勞磨損(點(diǎn)蝕)也是齒輪失效的主要形式,由于齒輪工作時(shí),齒面接觸應(yīng)力是按脈動(dòng)循環(huán)變化的,若齒面接觸應(yīng)力超過材料的接觸疲勞極限時(shí),齒面表層在載荷的多次重復(fù)作用下會(huì)產(chǎn)生細(xì)小裂紋

10、,隨著裂紋的生長(zhǎng),會(huì)產(chǎn)生小顆粒并徹底從齒面上脫落,形成點(diǎn)蝕。此這種麻點(diǎn)的形成又加速了齒輪的磨損,使齒輪的磨損更加嚴(yán)重。此外,在井下,因工作環(huán)境差,粉塵多,即使齒輪箱密封很好,也阻擋不住粉塵侵入箱體,造成潤(rùn)滑油的污染。油中的硬顆粒極易進(jìn)入齒輪嚙合區(qū),造成嚴(yán)重的磨粒性磨損,從而促使齒輪輪齒表面磨損加劇,發(fā)熱量增大。(4)鏈輪及軸承的磨損鏈輪在運(yùn)轉(zhuǎn)中除受靜載荷外,還受到很大的脈動(dòng)載荷和沖擊力,其失效形式主要是磨損。刮板輸送機(jī)通用技術(shù)條件(MT 105-1993)規(guī)定:輕型(<40 kW)刮板輸送機(jī)的鏈輪壽命不低于1 a,中(4090 kW)、重(>90 kW)型刮板輸送機(jī)的鏈輪壽命不低于

11、1·5 a。經(jīng)分析,造成鏈輪輪齒不耐磨的原因是:熱處理方法不當(dāng),即淬火層太淺,火焰淬火不均勻,淬火硬度偏低。刮板輸送機(jī)中軸承的磨損失效主要是在井下惡劣的環(huán)境中,軸承的潤(rùn)滑條件非常差所導(dǎo)致的。有的軸承甚至是在缺油的情況下工作,而這將直接導(dǎo)致軸承的急劇磨損和溫度上升,使軸承過熱燒壞。此外,工作過程中還伴隨著振動(dòng)沖擊,因此軸承磨損失效是沖擊與摩擦耦合作用的結(jié)果。刮板輸送機(jī)中除上述主要零部件存在嚴(yán)重的磨損外,其它一些零部件也同樣存在著較為嚴(yán)重的磨損,如減速箱中承受載荷最大一軸、減速箱軸承孔、機(jī)頭架中的鏈條入口和出口處、盲軸軸肩以及頭軸卸載處等。4對(duì)策(1)深入開展磨損機(jī)理研究,研究刮板輸送機(jī)

12、不同零部件的磨損形式及過程,特別是加強(qiáng)對(duì)關(guān)鍵性零部件的磨損機(jī)理的研究,只有弄清了它的磨損機(jī)理,才能采取行之有效的措施,如加強(qiáng)摩擦學(xué)設(shè)計(jì)的應(yīng)用等,從而提高輸送機(jī)的使用壽命。(2)加速新材料特別是復(fù)合材料的開發(fā)研究。主要是針對(duì)刮板輸送機(jī)的工作特點(diǎn)研發(fā)低摩擦抗磨材料,從而提高設(shè)備的耐磨性能。但在研究開發(fā)新材料的同時(shí),還要注重材料表面工程的研究,如利用耐磨涂層等表面保護(hù)手段來解決刮板輸送機(jī)易損件的磨損問題。(3)改善設(shè)備的使用條件,嚴(yán)格遵守操作規(guī)程,加強(qiáng)使用過程中的維護(hù),避免工況條件的惡化,如超速、超載、潤(rùn)滑不良等現(xiàn)象的發(fā)生。這將有利于提高設(shè)備工作可靠性。(4)把生產(chǎn)、使用、研究單位集合起來,共同開發(fā)

13、、商討、分析和試驗(yàn),改進(jìn)設(shè)計(jì)及生產(chǎn)制造工藝。但在現(xiàn)實(shí)生產(chǎn)中,設(shè)計(jì)、研發(fā)單位往往不了解具體使用單位對(duì)刮板輸送機(jī)的要求,只是使用統(tǒng)一的標(biāo)準(zhǔn)進(jìn)行設(shè)計(jì)、生產(chǎn)、制造,這直接導(dǎo)致刮板輸送機(jī)實(shí)際使用壽命遠(yuǎn)遠(yuǎn)達(dá)不到設(shè)計(jì)壽命。5 刮板輸送機(jī)上躥下跳的分析從工作面刮板輸送機(jī)的受力分析可知:只有工作面下端頭超前上端頭距離(或偽傾斜角度)選擇得比較恰當(dāng),推移或拉移刮板輸送機(jī)時(shí),沿工作面傾斜方向向上的分力和刮板輸送機(jī)同底板巖層間的摩擦力二者合力,與刮板輸送機(jī)的重力沿工作面傾斜方向向下分力平衡,才可使得推移或拉移刮板輸送機(jī)產(chǎn)生的上竄量剛好補(bǔ)償因重力作用而使刮板輸送機(jī)產(chǎn)生的下滑量,從而防止刮板輸送機(jī)“上竄下滑”。6工作面刮

14、板輸送機(jī)“上竄下滑”的危害綜放工作面前、后部輸送機(jī)“上竄下滑”影響工作面正常生產(chǎn),具體危害可列為以下幾個(gè)方面:(1) 引發(fā)機(jī)械事故。工作面前、后部刮板輸送機(jī)之間“上竄下滑”是伴隨的、相反的,若前部刮板輸送機(jī)“下滑”,勢(shì)必造成后部刮板輸送機(jī)相對(duì)“上竄”;若前部刮板輸送機(jī)“上竄”,勢(shì)必造成后部刮板輸送機(jī)相對(duì)“下滑”。由于工作面前、后部刮板輸送機(jī)與工作面運(yùn)輸巷轉(zhuǎn)載機(jī)轉(zhuǎn)載搭接不合理,勢(shì)必造成兩部刮板輸送機(jī)底鏈將煤炭帶入底槽,最終出現(xiàn)刮板輸送機(jī)過載開不動(dòng),強(qiáng)行“開車”或“倒車”,從而導(dǎo)致刮板輸送機(jī)斷鏈條等機(jī)械事故出現(xiàn)。(2) 影響工作面工程質(zhì)量。工作面刮板輸送機(jī)“上竄下滑”后,必然要采取一定措施,如工作

15、面兩端按比例調(diào)采。這就造成煤壁大線不直、支架調(diào)斜等問題,調(diào)整過程也是工作面工程質(zhì)量容易出現(xiàn)問題的過程。降低了生產(chǎn)效率。工作面刮板輸送機(jī)“上竄下滑”后,無論采取什么樣的措施,一方面增加了生產(chǎn)環(huán)節(jié),另一方面影響產(chǎn)量。如工作面兩端按比例調(diào)采,造成工作面一端推進(jìn)困難,煤機(jī)開機(jī)率低,勞動(dòng)組織不合理,不能按正規(guī)循環(huán)作業(yè),減少循環(huán)數(shù)等。4 增大了安全生產(chǎn)事故幾率。工作面刮板輸送機(jī)“上竄下滑”后,正常生產(chǎn)秩序被打破,不能正規(guī)循環(huán)作業(yè),增加了煤壁新暴露頂板無支護(hù)時(shí)間,不利于對(duì)頂板的管理,易造成煤幫冒頂事故。5 造成煤礦生產(chǎn)安全隱患。因刮板輸送機(jī)“上竄下滑”而堵塞采煤工作面的安全出口,一方面減少了通風(fēng)的有效斷面,

16、另一方面保證不了采煤工作面安全出口的行人暢通,對(duì)煤礦安全生產(chǎn)極為不利。7控制刮板輸送機(jī)“上竄下滑”的方法7.1合理設(shè)計(jì)設(shè)計(jì)工作面切眼位置時(shí),應(yīng)按照生產(chǎn)實(shí)際,設(shè)計(jì)工作面下端頭有一定超前距離。超前距離是指工作面沿兩巷垂直方向下端頭超前上端頭的距離。這是控制工作面刮板輸送機(jī)“上竄下滑”的第一步驟。但在實(shí)際巷道掘進(jìn)過程中,由于地質(zhì)構(gòu)造的存在,煤層傾角與原設(shè)計(jì)出現(xiàn)差別,往往造成工作面下端頭超前上端頭太多或太少的距離。工作面安裝后,試采過程中若不及時(shí)進(jìn)行調(diào)面,“上竄下滑”現(xiàn)象將特別嚴(yán)重,甚至不能正常組織生產(chǎn)。所以,在巷道掘進(jìn)施工中要根據(jù)煤層傾角變化及時(shí)修改設(shè)計(jì),盡量考慮在工作面下端頭留出適當(dāng)?shù)某熬嚯x。7

17、.2工作面調(diào)偽斜回采工作面調(diào)偽斜回采,即工作面下端頭超前上端頭。這是控制工作面刮板輸送機(jī)“上竄下滑”問題的一種主要方法。工作面試采后及時(shí)調(diào)面使工作面下端頭超前上端頭適當(dāng)距離,正?；夭蓵r(shí)工作面始終保持偽斜。當(dāng)工作面下端頭超前上端頭距離過多時(shí),將造成工作面前部刮板輸送機(jī)上竄,后部刮板輸送機(jī)相對(duì)下滑;當(dāng)工作面下端頭超前上端頭距離不足或下端頭滯后上端頭時(shí),將造成工作面前部刮板輸送機(jī)下滑,后部刮板輸送機(jī)相對(duì)上竄。7.3工作面單向推移或拉移刮板輸送機(jī)工作面單向推移或拉移刮板輸送機(jī),可人為使得刮板輸送機(jī)產(chǎn)生一定的上竄量或下滑量。若工作面刮板輸送機(jī)下滑,可單向推移前部刮板輸送機(jī),即當(dāng)煤機(jī)上行割煤時(shí),刮板輸送機(jī)

18、推移工作沿工作面傾斜方向由下而上順序進(jìn)行;當(dāng)煤機(jī)下行割煤時(shí),煤機(jī)空刀返回,由下而上推移,或沿工作面傾斜方向由上而下分段推移刮板輸送機(jī),在每一段內(nèi)仍由下而上順序推移。單向拉移后部刮板輸送機(jī),即刮板輸送機(jī)拉移工作沿工作面傾斜方向由下而上順序進(jìn)行。若工作面刮板輸送機(jī)上竄,按相反的方向即由上而下推移或拉移刮板輸送機(jī)。7.4使用單體液壓支柱輔助推移刮板輸送機(jī)當(dāng)工作面刮板輸送機(jī)出現(xiàn)“上竄下滑”時(shí),可用單體液壓支柱給刮板輸送機(jī)打支桿的方法控制前部刮板輸送機(jī)“上竄下滑”量,并且整體向上或向下移動(dòng)后部刮板輸送機(jī)。具體操作方法為:對(duì)于前部刮板輸送機(jī),將單體液壓支柱一端生根在支架的底座上,另一端打在刮板輸送機(jī)上,單

19、體液壓支柱遠(yuǎn)程送油,與推移刮板輸送機(jī)最好同時(shí)動(dòng)作,將刮板輸送機(jī)向“上竄下滑”相反的方向頂;對(duì)于后部刮板輸送機(jī)來說,可以用一組單體液壓支柱同時(shí)操作,將后部刮板輸送機(jī)整體移動(dòng)。單體液壓支柱數(shù)量根據(jù)工作面的傾斜長(zhǎng)度和角度而定,但在安全上應(yīng)注意單體液壓支柱生根牢固問題。7.5支架定位在生產(chǎn)過程中,要及時(shí)調(diào)整液壓支架的位置,使液壓支架及推移千斤頂同刮板輸送機(jī)呈垂直狀態(tài),液壓支架與工作面刮板輸送機(jī)互相制約;同時(shí)嚴(yán)格控制工作面采高,加強(qiáng)頂板控制,提高支架初撐力,避免支架因失穩(wěn)而傾倒,避免因支架不穩(wěn)定帶動(dòng)刮板輸送機(jī)“上竄下滑”。參考文獻(xiàn)：1萬長(zhǎng)慈:煤礦機(jī)電安全技術(shù).M.煤炭工業(yè)出版社19902韓英等:煤礦基層

20、干部必讀.M.吉林人民出版社、19903梁杰等:工程機(jī)械與電子控制.M.人民交通出版社、19984連為民.刮板輸送機(jī)斷鏈?zhǔn)鹿试蚍治黾邦A(yù)防J.煤礦開采,2002,7(4):75-77.5鄭樹琴,王琨.淺析煤礦機(jī)械傳動(dòng)齒輪的膠合失效J.山西煤炭,1996,(6):38-42.The common faults of scraper coveyor and countermeasuresSummary: Scraper conveyor is mine of mechanical, and it's normal use and safe operation of coal for imp

21、roving production efficiency and plays an important role in the economic benefits. In the process of scraper coveyor we often appear to break the chain, failure, such fault. Slide channeling. We must adopt corresponding measures to prevent and repair because these fault seriously affected the normal

22、 operation of belt conveyor .Keywords: scraper conveyor; broken chain; due to wear and failure; the channeling.1 Scraper conveyor chain of fault analysis of the reasons(1) With the increase of mining mechanization, Scraper conveyor in use process, basically is carrying loads. Long hours of two sproc

23、kets badly worn wear different or two sprockets asymmetry cause two chains stress imbalance, easily connected ring is pulled.(2) Scraper chain in the operation of the rigid content in coal was suddenly stuck in the mouth, or dislocation, easy in chute in scraper or connection, will ring scraper chai

24、n or produce very big impact, causing broken chain.(3) Scraper chain too tight, scraper conveyor, not only increase the operation of the early scraper chain tension, also make the scraper chain, and when the scraper chain stuck, no buffer room, scraper chain link, and the tension loading, it is easy

25、 to break. Scraper chain too loose or two chain scraper accident is differ, cause imbalances in operation, scraper chain sprocket place happening easily jump to connect, the impact of sprocket teeth are ring, deformation, fracture and chain scraper bending.(4) Scraper conveyor, coal, or in the overl

26、oad overload situation suddenly after stopping the chute didn't empty again started coal, increases the scraper chain under tension, especially early scraper chain wear to a certain extent easily broken.(5) Scraper chain severe wear, strength, impact load at repeatedly scraper chain fatigue dama

27、ge caused by the increase, and two scraper chain, from the chain link, make whole load were concentrated in a chain, that rupture.(6) Without bolt connection link in operation or loss caused by connecting bolts, only one force, connecting link chain ring is easily broken breakage. By underground wat

28、er corrosion, chain and peeling, rust scar section, it is easy to break strength.(7) Face slab, face is not straight, chute bottom float coal more stress caused by uneven chain scraper conveyor resistance increases, easy and broken chain.2 the measures takenAbove causes scraper conveyor chains are b

29、roken in the actual work frequently encountered .Do strengthen scraper chain of inspection and maintenance and adopt corresponding measures In order to make the scraper conveyor normal safety operation.(1) adjust sprocket wheel, making use of the sprocket teeth symmetrical . When two sprockets wear

30、degree, replace two sprockets that two chains, two chains in the balance of forces of scraper not inclined.(2) Insist on using hydraulic coupling, start to reduce no-load chain by impact load. Coal is the chute of coal must empty the chute in start-up, reduce the tension of the chain chain extension

31、 service life.(3) Use a period of scraper chain, chain removed flip 90 ° to use, exchange level with vertical chain scraper chain scraper so as to change the position of the worn parts to extend chain using life.(4) We should use the same length, wear the scraper chain, almost two scraper chain

32、 and best use of symmetrical to prevent chain pitch.(5) To prevent scraper chain too tight, too loose, the simplest method checking scraper chain tightness degree is: reverse some motivation, tighten the first motor chain, tighten scraper chain if the helicopter appeared two or more completely relax

33、ed scraper chain.(6) Scraper conveyor in use process, must be flat, straight, namely the conveyor, spread into a straight face. Scraper conveyor should avoid sharp curve; there should not be coal in scraper conveyor chute bottom; clean off the coal promptly to reduce scraper chain in the operation o

34、f the resistance.3 failure form and mechanism(1) the central trough wearThe central trough is scraper conveyor airframe components. In the process of operation, the side chain scraper conveyor by helicopter traction motor scraper and together with cargo slot in the middle. The central trough wear ma

35、inly divided into 5 (coal and gangue), scraper and chain plate and help to wear, and the coal mining machine movement along the central trough caused by the wear on wing tank. Among the central trough, tongue shall wear plate, plate usually especially serious can work normally, trough, the board wil

36、l help to wear the premature failure of central trough.(2) scraper chain wearScraper chain plate chain and early use forged chain,but now be with rings. Scraper chain is the main failure forms of the broken.And the investigation process chain to break chain about scraper conveyor accidents, new chai

37、n of therapeutic use 90 d cut increased obviously after the accident of chain. The scene with a broken accident of chain scraper chain manufacture quality or operation and maintenance of the "bad" broken accident, for the majority of chain of wear parts inspection replacement in the "

38、naturalness" caused by fault chain. Scraper conveyor chain and chute, cargo and contact friction, link and sprocket generated in the mesh chain chain and sliding friction, between the friction caused by relative motion to link all reasons work in susceptible to wear. Figure 1 is a chain worn pa

39、rts schemes. Wear mainly appear in three parts: the straight section, as shown in figure 1 line, this section is the worst part of the chain worn parts, mainly is the chain and chute and lots of friction betweenAs part of the circular arc, 2, this section is mainly due to wear after the helicopter w

40、ith chain sprocket wheel meshing process relative sliding friction; As part of the circular arc, 3, this part of the wear is mainly due to the contact between link chain in straight-line movement part extrusion and fatigue, and through the sprocket, link between the relative sliding friction and wea

41、r with extrusion. Link to wear directly, strength decreased diameter link, if not timely change will happen.Fig.1Wear parts of chainAccording to statistics, has worn scraper chain efficiency is lower than normal chains, and 6% to flat ring wear shoulder, even form on the shoulder "phenomenon, A

42、t the same time, flat ring and sprocket teeth, the contact area to climb chain, In addition, the chain operation after wearing the dynamic load, easy cause mechanical accident. Estimates, China every year because of the loss of accident of mechanical conveyor and coal output about 2 million tons. Be

43、cause of scraper coveyor working environment is bad. Chain during operation of the sliding friction role, even under a lot of static load and dynamic load, and mine water erosion, therefore, causing damage to the natural factors and dynamic load, general instantaneous impact stress corrosion and etc

44、.(3) gear wearWith mechanization and raise the level of modernization, the power of coal mine machinery is increasing, the machine, the output torque increase of coal mine machinery components of gear stress increases, especially But due to the use of coal mine machinery limited conditions and the s

45、ize of the gear, but not much change. In underground work environments of scraper coveyor gear teeth, the unit load value high (cm), 20kN/tooth surfaces wear very serious. See section scraper conveyor ZhuDongZhou arc tooth wimble gear 'reducers dao has worn. Gear failure seriously affect the nor

46、mal work of the scraper conveyor. Usually gear, gear tooth surface except in section for pure rolling line contact between the surfaces are relative sliding, inevitable meeting produces friction friction heat, and the temperature rise, make the tooth. Although gear transmission adopts gear oil lubri

47、cation, but because the vibration machine, the gear lubrication when nocd and boundary condition is poor, edge, variable impact and often start and stop to the existence of factors, even good lubrication measures, it will be difficult to form good lubricationConfiguration, so between normally bounda

48、ry lubrication condition. Gear work under huge loads, as between temperature elevatory, lubricant, the rupture between will direct contact area, causing wear, finally agglutination failure. Besides, surface fatigue failure plywood (pitting) is worn gear failure of main form, Due to the gear tooth su

49、rface work, contact stress is according to the change of circulation, if the pulsation of the tooth contact stress than material contact fatigue limit, tooth surface in load under the action of repeated tiny cracks will crack growth, with, can produce granules and completely off from tooth surfaces,

50、 pitting formation. The formation of hemp dot and accelerate the gear, gear abrasion wear more serious. In addition, in underground work environment, because, dust, even gear box seal is very good, also cannot stop dust into the oil pollution, cabinet The hard particles into gear area, easy cause se

51、rious abrasive wear, which prompted the sexual gear tooth surface, increase calorific value.(4) sprocket and bearing of wear and tearExcept in the operation of sprocket static load, still very big ripple load and impact, the failure forms of the main is worn. The general condition of scraper coveyor

52、 (MT 105-1993) : light (< 40 kW) scraper conveyor chain of life not less than 1, (40-90 kW), heavy (> 90 kW) scraper conveyor chain of lifeBelow 1, 5. Through analysis of the reasons sprocket teeth don't wear is undeserved, namely, heat treatment, flame hardening layer is too shallow uneve

53、n hardness, quench hardened. Scraper conveyor in bearing failure is mainly in the underground bad environment, the lubrication condition is very poor. Some bearing is under the condition of oil in the lack of work, but it will directly cause bearing temperature rise sharply, abrasion and bearing ove

54、rheating burn out In addition, the working process with vibration shock, therefore bearing failure is the impact and friction coupling results. Scraper conveyor in addition to the main component exists serious wear, other parts also exists serious wear, such as gearbox of axial load, the largest red

55、ucer bearing hole, head of the plane entrance and exit, blind chain axial shaft shoulder and axial uninstall place etc. Head,4 countermeasures(1) further study, wear mechanisms of different parts of scraper coveyor and process, especially wear form to strengthen key components of the wear mechanism,

56、 it is clear to wear mechanism, can effective measures, such as strengthening the tribological design, so as to improve the application of longevity.(2) Accelerate new materials, especially the development of composite materials. Aimed at the working characteristics of scraper coveyor r&d low fr

57、iction abrasion-resistant materials, so as to improve the equipment of wear-resisting performance. In the research and development of new materials, notice the material surface engineering research, such as using wear-resisting coating surface protection methods to solve the scraper conveyor wear pa

58、rts.(3) Improve equipment conditions of use, strictly abide by the procedures, strengthen the maintenance, avoid to use the deteriorating conditions, such as speed, overload, bad lubrication, etc. This will be conducive to improving the working reliability.(4) The production, use and research unit t

59、ogether, common development, to discuss, analysis and test, improved design and manufacturing process. But in reality, the design, the production of r&d unit often do not understand specific use unit of scraper coveyor, just use uniform standard design, production and manufacturing, the direct cause of scraper coveyor actual life far less than the design life.5 scraper conveyor jumping analysisFrom the face of scraper coveyor stress analysis shows that only