雙刮板鏈?zhǔn)浇o料機(jī)設(shè)計(jì)

雙刮板鏈?zhǔn)浇o料機(jī)設(shè)計(jì),雙刮板鏈?zhǔn)浇o料機(jī)設(shè)計(jì),雙刮板,鏈?zhǔn)?設(shè)計(jì) 摘要刮板輸送機(jī)是礦山運(yùn)輸機(jī)械的重要組成部分，作為具有撓性牽引力的連續(xù)輸送機(jī)械，它被廣泛用作采煤工作面和煤巷的運(yùn)輸工具。在此設(shè)計(jì)中，對組成刮板輸送機(jī)的部件結(jié)構(gòu)進(jìn)行分析和計(jì)算，并著重設(shè)計(jì)了減速器等部件的結(jié)構(gòu)。刮板輸送機(jī)的動(dòng)力裝置采用防爆異步電動(dòng)機(jī)，減速器使用自行設(shè)計(jì)的三級錐齒輪減速器。機(jī)頭鏈輪是由電動(dòng)機(jī)通過液力耦合器與減速器連接傳動(dòng)到的，從動(dòng)力部分開始傳動(dòng)，從而帶動(dòng)下一級的傳動(dòng)，一級帶著一級，在這段工作的時(shí)間內(nèi)刮板運(yùn)動(dòng)是重復(fù)的，從而物料循環(huán)的完成任務(wù)。刮板輸送機(jī)在礦井下相當(dāng)于領(lǐng)導(dǎo)者地位，它可以代替工人在礦井下工作。這樣不僅可以保證了工人的安全，還大大提高了相比較人工而言緩慢的工作效率，效率一提高帶給公司的就是很直接的利益。因此，對刮板輸送機(jī)進(jìn)行更深層次的研究和改進(jìn)對煤炭工業(yè)的發(fā)展是非常有必要的，對時(shí)代文明的快速進(jìn)步有非凡意義。關(guān)鍵詞 刮板鏈；中部槽；減速器IAbstractThe scraper conveyor is an important part of the mine transportation machinery. As a continuous conveying machine with flexible traction force, it is widely used as a transportation tool for coal mining face and coal roadway. In this design, the component structure of scraper conveyor is analyzed and calculated, and the structure of reducer and other components is emphatically designed. The power unit of scraper conveyor adopts explosion-proof asynchronous motor, and the reducer uses a self designed three stage bevel gear reducer. The head sprocket is driven by the motor through the hydraulic coupler and the reducer, starting from the power part, thus driving the next level, and the first level with the first level. In this period, the scraper movement is repeated, thus the material circulation is completed. The scraper conveyor is equal to the leader position under the mine, it can replace the worker to work under the mine. This can not only guarantee the safety of the workers, but also greatly improve the efficiency of the slow work in comparison with the manual, and the efficiency is directly beneficial to the company. Therefore, the further research and improvement of the scraper conveyor is very necessary for the development of the coal industry, and it is of great significance to the rapid progress of the times civilization.Keywords scraper chain middle slot reduceII目 錄摘要IABSTRACTII1 緒論11.1 刮板輸送機(jī)的研究目的及意義11.2 刮板輸送機(jī)的總體走向11.2.1 國內(nèi)的發(fā)展走向11.2.2 國外的發(fā)展走向11.3 刮板輸送機(jī)的概述11.3.1 刮板輸送機(jī)的部件構(gòu)成11.3.2 刮板輸送機(jī)的工作原理21.3.3 刮板輸送機(jī)的適用場合21.4刮板輸送機(jī)的種類22 刮板輸送機(jī)的設(shè)計(jì)22.1設(shè)計(jì)參數(shù)的總需求22.2 總體方案的設(shè)計(jì)32.2.1 輸送能力的計(jì)算32.2.2 運(yùn)行阻力的計(jì)算32.2.3 電動(dòng)機(jī)功率的確定與選型42.2.4 刮板鏈強(qiáng)度的驗(yàn)算42.3 刮板輸送機(jī)機(jī)頭部及傳動(dòng)裝置42.3.1 機(jī)頭架42.3.2 減速器52.3.3 液力耦合器52.3.4 鏈輪組件62.3.5 盲軸組件62.4 溜槽及附件62.4.1 溜槽62.4.2 附件72.5 刮板鏈72.5.1 刮板鏈的特性72.5.2 刮板鏈的選型與技術(shù)要求72.6 緊鏈裝置82.7 推移裝置83 減速器的設(shè)計(jì)83.1 傳動(dòng)系統(tǒng)的確定83.1.1 總傳動(dòng)比及傳動(dòng)比分配83.1.2 運(yùn)動(dòng)參數(shù)的計(jì)算93.2 齒輪的設(shè)計(jì)103.2.1 弧齒圓錐齒輪的傳動(dòng)設(shè)計(jì)計(jì)算103.2.2 斜齒圓柱齒輪的傳動(dòng)設(shè)計(jì)計(jì)算123.2.3 直齒圓柱齒輪的傳動(dòng)設(shè)計(jì)計(jì)算153.3 減速器的軸的設(shè)計(jì)與校核183.3.1 高速軸（1軸）的設(shè)計(jì)183.3.2 軸2的設(shè)計(jì)與校核223.3.3 軸3的設(shè)計(jì)與校核253.4 軸承壽命的校核計(jì)算293.4.1 軸1處軸承壽命的校核293.5 鍵的強(qiáng)度校核303.5.1 軸2上的鍵強(qiáng)度校核304 刮板輸送機(jī)的安裝、運(yùn)轉(zhuǎn)、維護(hù)314.1 刮板輸送機(jī)的安裝314.2 刮板輸送機(jī)的運(yùn)轉(zhuǎn)314.3 刮板輸送機(jī)的維護(hù)31結(jié)論32致謝33參考文獻(xiàn)34IV1. 緒論1.1 刮板輸送機(jī)的研究目的及意義中國每年煤炭的出口貿(mào)易量占到世界總量的12%，是當(dāng)之無愧的世界上最大的煤炭生產(chǎn)國和消費(fèi)國。隨著近幾年來我國的快速發(fā)展，高產(chǎn)高效集約化礦山的生產(chǎn)模式正在一步步的逐漸形成，這正是為了努力實(shí)現(xiàn)高度一體化的一礦一井一面生產(chǎn)模式。在過去半個(gè)世紀(jì)的發(fā)展過程中，科技的進(jìn)步是又一歷史性飛躍，刮板輸送機(jī)現(xiàn)已成為礦井下作業(yè)時(shí)不可或缺的產(chǎn)品之一。一個(gè)產(chǎn)品能否占領(lǐng)市場主要看產(chǎn)品在投入市場使用后的反饋程度。哪一個(gè)產(chǎn)品的適用范圍能最廣，帶給生廠商的利益能最大化，那么它就更容易被大眾接受。因此，研究改造或創(chuàng)新可以說是迫在眉睫，提高工作面的高產(chǎn)量和高效率來實(shí)現(xiàn)促進(jìn)煤炭工業(yè)的進(jìn)一步發(fā)展。1.2 刮板輸送機(jī)的總體走向1.2.1 國內(nèi)的發(fā)展走向在上個(gè)世紀(jì)的70年代左右，綜采機(jī)械化開始慢慢的在中國部分地區(qū)投入使用。經(jīng)過那么多年的發(fā)展，我國現(xiàn)可以自主研究制造中小型功率的刮板輸送機(jī)，而發(fā)展并沒有那么迅速的大功率型的刮板輸送機(jī)還需通過引進(jìn)國外設(shè)備的先進(jìn)技術(shù)進(jìn)行開發(fā)研究。由于先期缺乏理論實(shí)踐的支持，并且工業(yè)水平受限，所以在我國目前存在的顯著問題主要體現(xiàn)在安全性和可靠性。市場的激烈競爭和產(chǎn)品更迭，技術(shù)不能止步不前，刮板輸送機(jī)必須改進(jìn)才能保證不被市場淘汰。所以輸送機(jī)的近期目標(biāo)是朝著輸送量要多、傳遞的功率要大、技術(shù)要先進(jìn)、性能要可靠、設(shè)備要安全、機(jī)電一體化的總體方向走的。我國未來規(guī)劃的大方向是保持原有節(jié)奏的基礎(chǔ)上的同時(shí)盡可能快的追趕上發(fā)達(dá)國家的研究水平，早日成為一個(gè)不可小覷的大國。1.2.2 國外的發(fā)展走向第一臺(tái)刮板輸送機(jī)在世界上的問世讓人們以不斷創(chuàng)新改革建設(shè)礦井運(yùn)輸?shù)闹袠袨槟繕?biāo)，發(fā)達(dá)國家在于這方面的研究成果不僅僅只體現(xiàn)在輸送機(jī)的生產(chǎn)能力和功率上，更多則展現(xiàn)了輸送機(jī)設(shè)備的先進(jìn)化上。正是秉著科技是第一生產(chǎn)力，永遠(yuǎn)需要?jiǎng)?chuàng)新的宗旨，時(shí)代才能如此發(fā)展快速。盡管發(fā)達(dá)國家現(xiàn)在自身擁有的機(jī)械制造工藝已經(jīng)相當(dāng)成熟，但是為了滿足更多人們的需求，還是在不斷的創(chuàng)新著。隨著測量技術(shù)的微電子技術(shù)發(fā)展，科研人員的研究方向瞄準(zhǔn)了現(xiàn)代智能化，控制電路數(shù)字化、智能化即將成為未來的發(fā)展走向。1.3 刮板輸送機(jī)的概述1.3.1 刮板輸送機(jī)的部件構(gòu)成現(xiàn)如今市面上的輸送機(jī)類型型號的種類繁多，每一種類都有專屬于自己的獨(dú)特特色。雖然每一個(gè)輸送機(jī)部件的形式和布置方式都盡不相同，但是基本組成結(jié)構(gòu)是相同的，即一般構(gòu)件為機(jī)頭部、機(jī)尾部、中間槽等。輸送機(jī)的外形見圖1-1。圖1-1 刮板輸送機(jī)1.3.2 刮板輸送機(jī)的工作原理電機(jī)經(jīng)液力耦合器和減速器相連，減速器與鏈輪相連，刮板固定在鏈條上組成刮板鏈，帶動(dòng)機(jī)頭軸的鏈輪旋轉(zhuǎn)。從而帶動(dòng)下一級的傳動(dòng)，一級帶著一級，在這段工作的時(shí)間內(nèi)刮板運(yùn)動(dòng)是重復(fù)的。然后當(dāng)物料運(yùn)送到機(jī)器末端時(shí)就停止輸送然后將物料拆卸下來。從而完成刮板的一系列完整的運(yùn)動(dòng)。1.3.3 刮板輸送機(jī)的適用場合刮板輸送機(jī)的結(jié)構(gòu)強(qiáng)度高，機(jī)身矮，可彎曲，能適應(yīng)非常惡劣的工作條件，比如礦井，冶金，化工等場合。當(dāng)刮板輸送機(jī)移動(dòng)時(shí)，鏟煤板能夠自動(dòng)清理機(jī)道中的浮煤。由于礦井下的不安全性，刮板輸送機(jī)可以顯著改善工人的工作環(huán)境，所以刮板輸送機(jī)現(xiàn)在仍是緩傾斜長壁式采煤工作面唯一的煤炭運(yùn)輸設(shè)備。1.4 刮板輸送機(jī)的種類輸送機(jī)可以按照溜槽的布置方式的不同可以分為兩種形式：并列式、重疊式；輸送機(jī)可以按照鏈條數(shù)目和排列方式的不同分為四種形式：單鏈、中雙鏈、邊雙鏈、三鏈；輸送機(jī)可以按照傳遞功率的大小分為三種形式：輕型、中型、重型。2 刮板輸送機(jī)的設(shè)計(jì)2.1 設(shè)計(jì)參數(shù)的總需求畢業(yè)設(shè)計(jì)題目是雙刮板鏈?zhǔn)浇o料機(jī)設(shè)計(jì)。設(shè)計(jì)參數(shù)：生產(chǎn)能力：9001200t/h，刮板速度可調(diào)（參考）：0.8m/s，中部槽寬度：8501000mm，給料層調(diào)節(jié)范圍：420580mm，參考總體長度：38004100mm，外寬：13801525mm。 2.2 總體方案的設(shè)計(jì)2.2.1 輸送能力的計(jì)算作為具有撓性牽引力的連續(xù)輸送機(jī)械，刮板輸送機(jī)的輸送能力見(2-1)。 （2-1） 2.2.2 運(yùn)行阻力的計(jì)算重段直線段運(yùn)行的阻力為見（2-2）。 （2-2）空段直線段的運(yùn)行阻力為見（2-3）。 （2-3） 已知中雙鏈由于在過程中存在著另外增加的阻力，刮板輸送機(jī)的總的運(yùn)行阻力見（2-4）。 （2-4）將數(shù)據(jù)代入（2-4）計(jì)算,得,2.2.3 電動(dòng)機(jī)功率的確定與選型電動(dòng)機(jī)的功率見（2-5）。 （2-5）式中 刮板輸送機(jī)總運(yùn)行阻力，N 刮板鏈運(yùn)行速度，m/s 傳送裝置效率將已知數(shù)據(jù)代入（2-5）,得,因?yàn)榈V井的深度可以達(dá)到很深，所以輸送機(jī)的電機(jī)在礦井下很難安全有效的制動(dòng)。為了保證在一些惡劣的環(huán)境條件下能夠作業(yè)安全，所以我們對電機(jī)的要求是防爆和防電火花。所以選定的電動(dòng)機(jī)類型為YB2-160M-4，其主要參數(shù)數(shù)據(jù)如下：額定功率：11kw電機(jī)轉(zhuǎn)速：1460r/min額定電壓：380v滿載效率：0.914滿載功率因數(shù)：0.85冷卻方式：外殼水冷2.2.4 刮板鏈強(qiáng)度的驗(yàn)算刮板鏈強(qiáng)度需要滿足見（2-6）。 （2-6） 將數(shù)據(jù)代入式（2-6）,得, 所以該圓環(huán)鏈滿足強(qiáng)度的條件。2.3 刮板輸送機(jī)機(jī)頭部及傳動(dòng)裝置2.3.1 機(jī)頭架機(jī)頭架是支承和裝配機(jī)頭傳動(dòng)裝置（包括電動(dòng)機(jī)、液力耦合器、減速器等）、鏈輪組件、盲軸以及其他附屬裝置的構(gòu)件。它是由厚鋼板焊接而成的，具有較高的強(qiáng)度和剛度對機(jī)頭架的基本結(jié)構(gòu)要求是，兩側(cè)結(jié)構(gòu)必須相同，便于左右工作面的交替使用和雙側(cè)傳動(dòng)。為了便于井下的安裝與拆卸，在分離點(diǎn)的時(shí)候刮板鏈很容易卷進(jìn)去，所以鏈輪的兩端分別使用減速器和盲軸來穩(wěn)固。機(jī)頭架的前面有兩個(gè)東西固定著它。護(hù)軸板是易損部位，代替使用可拆卸的活板，不僅方便拆裝，還方便更換，這樣兩全其美。2.3.2 減速器減速器是常常被用在電動(dòng)機(jī)和傳動(dòng)裝置之間的減速傳動(dòng)裝置。本次使用的自行設(shè)計(jì)的三級圓錐圓柱齒輪減速器，節(jié)省井下作業(yè)空間采用垂直方式，其次三級展開來說就是一級是弧齒錐齒輪在高速級，二級是斜齒圓柱齒輪，三級是直齒圓柱齒輪。盡管三級減速器的成本相對于其他減速器而言較高，但是其突出的優(yōu)勢還是受到了使用者們廣泛的喜愛。它的結(jié)構(gòu)尺寸較小，便于拆裝，減速效果在最大程度上減少了力矩，使產(chǎn)品的使用壽命到了延長。第三章內(nèi)容就是主要講解減速器，三級減速器傳動(dòng)的方案見圖2-1。圖2-1傳動(dòng)結(jié)構(gòu)簡圖2.3.3 液力耦合器液力耦合器作為聯(lián)軸器的一種，主要由泵輪、渦輪組成，有過載保護(hù)功能，減少傳動(dòng)系統(tǒng)的沖擊和振動(dòng)等優(yōu)點(diǎn)。其結(jié)構(gòu)見圖2-2。圖2-2 液力耦合器的結(jié)構(gòu)圖通過比較聯(lián)軸器的型號初步選定的是限矩型液力耦合器，型號為YOX206D，其主要參數(shù)數(shù)據(jù)如下所示：輸入轉(zhuǎn)速n=1500r/min ，重量9.5kg2.3.4 鏈輪組件因?yàn)殒溳喗M件的形式有很多，通常都裝配在機(jī)構(gòu)的首末兩端。所以要求有足夠的強(qiáng)剛度和韌性。在工作的鏈輪不但有自身的重力，還要受到外界部件給它帶來拉力以及壓力，還有在工作時(shí)會(huì)產(chǎn)生沖擊。所以我們要求鏈輪這個(gè)部件不但能夠便于工作人員的安裝也能快速準(zhǔn)確的拆下來，這樣既能節(jié)省時(shí)間也能節(jié)省人力物力。整體式鏈輪組件見圖2-3。圖2-3整體式鏈輪組件2.3.5 盲軸組件盲軸由花鍵軸、花鍵套、箱體等組成，主要作用是支承鏈輪，使用前應(yīng)檢查注油孔是否堵塞。2.4 溜槽及附件2.4.1 溜槽溜槽作為刮板輸送機(jī)的主要部件之一，刮板輸送機(jī)的工作效率離不開槽的長度和寬度，這占有了很大的原因。中部槽裝配時(shí)需要注意平、直、穩(wěn)。過渡槽和調(diào)節(jié)槽的基本結(jié)構(gòu)是差不多的，只是后者一個(gè)根據(jù)工作面長度變化而變化。2.4.2 附件附件其實(shí)有很多，但是通常所談?wù)摰亩际恰皟砂逡徊邸薄蓚€(gè)板都是裝在側(cè)面空的一個(gè)地方，主要也是幫助刮板輸送機(jī)提高工作效率，不出現(xiàn)一些重大事故。因此需要它有足夠的強(qiáng)剛度來保證作業(yè)安全。2.5 刮板鏈2.5.1 刮板鏈的特性刮板固定在鏈條上組成了刮板鏈，鑒于刮板鏈的工作特點(diǎn)，要求其具有以下特征：圓環(huán)鏈抗拉強(qiáng)度要高，耐磨性要好，耐疲勞性能要好，抗腐蝕性要強(qiáng)。圓環(huán)鏈的優(yōu)點(diǎn)就比較明顯，尤其中雙鏈更是佼佼者。它的均勻受力、較高的抗磨損和抗拉強(qiáng)度更是為其優(yōu)勢增添了幾份色彩。2.5.2 刮板鏈的選型與技術(shù)要求根據(jù)礦用高強(qiáng)度圓環(huán)鏈GB/T12178-2001標(biāo)準(zhǔn)選取鏈條，本刮板輸送機(jī)鏈條的形式是中雙鏈，它的類型尺寸結(jié)構(gòu)是34126-D，由于形狀限制要求了熱處理工藝方式，只是為了能夠更好的呈現(xiàn)和合理制造，見圖2-4。圖2-4中雙鏈?zhǔn)焦伟彐?.6 緊鏈裝置刮板鏈在運(yùn)行時(shí)需要存在不同程度的張力，為了給輸送機(jī)這個(gè)力是需要給它增加一個(gè)緊鏈裝置。為使刮板輸送機(jī)安全運(yùn)行，新安裝或正在運(yùn)行中的刮板輸送機(jī)都是需要緊鏈。2.7 推移裝置推移裝置是在采煤工作面內(nèi)將刮板輸送機(jī)向煤壁推移的裝置。綜采工作面使用液壓支架上的推移千斤頂，非綜采工作面用單體液壓推溜器或手動(dòng)液壓推溜器。83 減速器的設(shè)計(jì)3.1 傳動(dòng)系統(tǒng)的確定傳動(dòng)系統(tǒng)是在原有的基礎(chǔ)上進(jìn)行學(xué)習(xí)研究，根據(jù)任務(wù)書上的參數(shù)要求，然后再通過老師的指導(dǎo)來確定系統(tǒng)。3.1.1 總傳動(dòng)比及傳動(dòng)比分配（1）總傳動(dòng)比由圖2-1可知輸入轉(zhuǎn)速等于電機(jī)轉(zhuǎn)速，即選擇的圓環(huán)鏈的型號是34126，根據(jù)綜采技術(shù)手冊見（3-1）。 （3-1）將已知數(shù)據(jù)代入（3-1），得，=585.09mm586mm鏈輪的轉(zhuǎn)速見（3-2）， （3-2）式中 v 刮板鏈的速度將已知數(shù)據(jù)代入（3-2），得，因此總傳動(dòng)比為（2）傳動(dòng)比分配 一級弧齒圓錐齒輪傳動(dòng)的傳動(dòng)比為，根據(jù)機(jī)械設(shè)計(jì)得減速器的傳動(dòng)比分配為。 3.1.2 運(yùn)動(dòng)參數(shù)的計(jì)算從減速器的高速軸出來的第一個(gè)軸為1軸，第二根軸為2軸，第三根軸為3軸，第四根軸為4軸。（1）轉(zhuǎn)速的計(jì)算（2）功率的計(jì)算 （3）轉(zhuǎn)矩的計(jì)算3.2 齒輪的設(shè)計(jì)3.2.1 弧齒圓錐齒輪的傳動(dòng)設(shè)計(jì)計(jì)算1.初步選定基本參數(shù) （1）選用7級精度（2）小圓錐齒輪材料是40Cr，大圓錐齒輪材料是45（3）初步選定的兩輪的齒數(shù)分別是2.根據(jù)齒面接觸疲勞強(qiáng)度設(shè)計(jì)（1）小齒輪分度圓直徑的試驗(yàn)計(jì)算，見（3-3）。 （3-3） 初步選定傳遞的小輪轉(zhuǎn)矩 選定齒寬系數(shù)，材料的彈性影響系數(shù)主從動(dòng)輪上的齒輪的接觸疲勞許用應(yīng)力分別是，見（3-4）。 （3-4） 將已知數(shù)據(jù)代入（3-4），得，S=1所以在這里選定的相比較來說比較小的值2），代入（3-3）得，試著調(diào)整得v和。2） 計(jì)算實(shí)際載荷系數(shù)，則接觸強(qiáng)度載荷系數(shù)3） 改定后的分度圓直徑為3.根據(jù)齒根彎曲疲勞強(qiáng)度設(shè)計(jì)（1）模數(shù) （3-5）主從動(dòng)輪的齒根彎曲疲勞強(qiáng)度極限分別為，彎曲疲勞壽命系數(shù)齒形系數(shù)由于彎曲疲勞會(huì)產(chǎn)生一定程度上的失效，在這里取S=1.4在比較大小齒輪值后選擇大一點(diǎn)數(shù)值的值。2） 試算3） 改定齒輪模數(shù)（2）計(jì)算（3）根據(jù)實(shí)際載荷系數(shù)計(jì)算出來的齒輪模數(shù)相應(yīng)的選擇齒數(shù)所以在這里選定,，所以1.幾何尺寸（1）分度圓（2）分錐角（3）齒輪寬度3.2.2 斜齒圓柱齒輪的傳動(dòng)設(shè)計(jì)計(jì)算1. 初步選定基本參數(shù)（1）選定7級精度（2）小齒輪的材料是40Cr,大齒輪的材料是45 （3）初步選定的兩輪齒數(shù)分別為，（4）初步選定，2.根據(jù)齒面接觸疲勞強(qiáng)度設(shè)計(jì)（1）初步選小齒輪分度圓直徑，見（3-6）。 （3-6）1）確定公式中的各個(gè)參數(shù)的值初步選定選載荷系數(shù)傳遞的小齒輪轉(zhuǎn)矩 主從動(dòng)輪的接觸疲勞強(qiáng)度極限分別為，計(jì)算應(yīng)力循環(huán)次數(shù)式中：小圓柱齒輪的轉(zhuǎn)速，=486.67r/min齒輪每轉(zhuǎn)一周時(shí)同一齒面的嚙合數(shù)， ， ，將已知數(shù)據(jù)代入（3-6），得2） v3） b 4） mt和h5） 計(jì)算使用系數(shù)動(dòng)載系數(shù)，齒間載荷分配系數(shù)，6） 改定后所得的分度圓直徑7） 計(jì)算模數(shù)m3.根據(jù)設(shè)計(jì)（1）試算載荷系數(shù)（2），在比較大小齒輪值后選擇大一點(diǎn)數(shù)值的值。（5），代入（3-7）得， （3-7）1）圓周速度2）齒寬3）齒高h(yuǎn)及齒高比b/h4)根據(jù)算得的齒輪模數(shù)4.幾何尺寸（1）中心距（2）螺旋角（3）分度圓直徑d(4） 根圓直徑 （5） 頂圓直徑 （6）齒輪寬度b3.2.3 直齒圓柱齒輪的傳動(dòng)設(shè)計(jì)計(jì)算1. 初步選定基本參數(shù)（1）選用7級精度（2）小齒輪材料是20CrMnTi ，大齒輪材料是45 （3）初步選定兩輪齒數(shù)分別為，（4）初步選定2. 根據(jù)，見（3-8）。 （3-8）1） 確定公式中的各參數(shù)值初步選定傳遞的小齒輪的轉(zhuǎn)矩齒寬系數(shù)區(qū)域系數(shù)彈性影響系數(shù)主從動(dòng)輪上齒數(shù)的接觸疲勞強(qiáng)度極限分別是，。在比較之后選擇小一點(diǎn)的數(shù)值的值=2），代入（3-8）得，（1） 改定vb1）計(jì)算使用系數(shù)動(dòng)載系數(shù)齒間載荷系數(shù),2） 改定后的3. 根據(jù)（1）試算，見(3-9)。 （3-9）1） 初步選定2） 齒形系數(shù)3）4） 主從動(dòng)輪上的分別為，5）所以大小齒輪值比較后選擇大一點(diǎn)的數(shù)值的值。（2）改定vbb/h3） 計(jì)算動(dòng)載系數(shù)齒間載荷分配系數(shù)，（4）根據(jù)以上數(shù)據(jù)選定主從動(dòng)輪上的齒數(shù)分別為4. 幾何尺寸計(jì)算（1）計(jì)算分度圓直徑 （2）計(jì)算中心距 （3）計(jì)算根圓直徑 （4）計(jì)算頂圓直徑 （5）計(jì)算齒輪寬度b考慮不可避免的安裝誤差，為了保證設(shè)計(jì)齒寬b和節(jié)省材料，一般將小齒輪略微加寬（5-10）mm,即即取，而使大齒輪的齒寬等于設(shè)計(jì)齒寬，即5. 圓整中心距后的強(qiáng)度校核，齒面接觸疲勞強(qiáng)度和齒根彎曲疲勞強(qiáng)度都滿足要求。 3.3 減速器的軸的設(shè)計(jì)與校核3.3.1 高速軸（1軸）的設(shè)計(jì)（1）（2）錐齒輪受力分析圓周力徑向力軸向力（3）確定軸的最小直徑材料選擇是20CrMnTi，熱處理方式是滲碳淬火，計(jì)算時(shí)由于其他零部件產(chǎn)生的影響作用，在原來的計(jì)算基礎(chǔ)上需要增加3%的誤差。最后取105計(jì)算，得，（4）軸的結(jié)構(gòu)設(shè)計(jì) 軸段1：這一段軸的直徑是連接在液力耦合器一起的，所以需要根據(jù)液力耦合器的孔徑來取，。軸段2：這一段的左邊因?yàn)橐c位于軸段1的右端的定位軸肩相互影響，所以取。因?yàn)槲挥谳S段左邊的減速器配合使用軸承端蓋，所以軸承端蓋長度為。因?yàn)榘惭b與拆卸的要求，所以端蓋外部與液力耦合器右端距離為30mm，。軸段3：這一段上面裝有軸承，由于軸承即受徑向力也受軸向力，且為了裝拆軸承內(nèi)圈，類型選定圓錐滾子軸承，其類型30212，所以，。軸段4：取右端定位軸肩高度，。軸段5：因?yàn)辇X輪比較小的原因，所以這個(gè)部分是一個(gè)齒輪軸，。（5）確定軸承點(diǎn)和軸承位置的軸承點(diǎn)尺寸先確定軸承支點(diǎn)位置，查30212軸承，其支點(diǎn)尺寸，因此兩軸承支點(diǎn)之間的距離右端軸承的支承點(diǎn)到齒輪載荷作用點(diǎn)距離左端軸承的支承點(diǎn)到軸段1的支承點(diǎn)的距離圖3-1軸1的設(shè)計(jì)圖（6）1）求軸承反力水平面H ， 垂直面V ，2）水平面H ，垂直面V合成M ，扭距T（7）按合成強(qiáng)度檢驗(yàn)軸的強(qiáng)度取折合系數(shù)則齒寬中點(diǎn)處當(dāng)量彎距 由于材料為20CrMnTi鋼的，。則軸的應(yīng)力在計(jì)算時(shí)需要滿足條件， 經(jīng)過數(shù)據(jù)顯示可以得知該軸滿足強(qiáng)度條件。（8）軸1計(jì)算簡圖見3-2。圖3-2軸1計(jì)算簡圖3.3.2 軸2的設(shè)計(jì)與校核（1）（2）弧齒輪上所受的力 （3）斜齒輪上所受的力 （4）確定軸的最小直徑材料選擇是20CrMnTi，熱處理方式是滲碳淬火，計(jì)算時(shí)由于其他零部件產(chǎn)生的影響作用，在原來的計(jì)算基礎(chǔ)上需要增加3%的誤差。最后取105計(jì)算，得，（5）軸的結(jié)構(gòu)設(shè)計(jì) 圖3-3軸2的設(shè)計(jì)軸段1：這一段上面裝的圓錐滾子軸承，符合軸承內(nèi)徑，所以它的型號是32909，。所以取，。軸段2：這一段上面的長度應(yīng)該取 。軸段3：這一段上面裝的是斜齒輪，所以，。軸段4：取齒輪左端定位軸肩高度，。軸段5：因?yàn)辇X輪相對比較小的原因，所以把它用作齒輪軸，。軸段6：這一段上面的軸肩應(yīng)該是要與右邊軸肩一樣大小，故，。軸段7：這一段是用來安裝軸承，所以取，。根據(jù)直徑75mm，軸承類型是圓錐滾子軸承，類型為32917，它的參數(shù)：，。根據(jù)數(shù)值查閱圖書在這里給軸承選擇的油脂潤滑（5）確定軸承及齒輪作用力的距離位置 圖3-4軸2的計(jì)算簡圖1） 求軸承反力水平面H ， 垂直面V ，2） 求水平面H 垂直面V 合成M，（7）檢驗(yàn)軸的強(qiáng)度由于材料為20CrMnTi，則軸的應(yīng)力在計(jì)算時(shí)需要滿足條件，經(jīng)過數(shù)據(jù)顯示可以得知軸滿足強(qiáng)度條件。3.3.3 軸3的設(shè)計(jì)與校核（1）（2） （3） （4）確定軸的最小直徑材料選擇是20CrMnTi，熱處理方式是滲碳淬火，計(jì)算時(shí)由于其他零部件產(chǎn)生的影響作用，在原來的計(jì)算基礎(chǔ)上需要增加3%的誤差。最后取105計(jì)算，得，（5）軸的結(jié)構(gòu)設(shè)計(jì) 圖3-5軸3的設(shè)計(jì)圖 軸段1：滾動(dòng)軸承按結(jié)構(gòu)設(shè)計(jì)應(yīng)該安裝在這一段上，因?yàn)榭紤]軸承不僅會(huì)受到徑向力同時(shí)也會(huì)受到軸向力,再加上還需要顧慮軸的最小直徑的問題，所以選定的類型是圓錐滾子軸承。這里取軸段的直徑為，類型32911,，所以，軸段2：因?yàn)檩S段1的右端具有軸肩，用于定位。軸肩的高度是h=20mm,所以軸段2直徑取。最后根據(jù)整體的裝配尺寸取，。軸段3：由于齒輪較小，在此把齒輪與軸作為一體，所以,。軸段4：因?yàn)檫@一段為軸肩，考慮到大圓柱齒輪的定位以及加工方便，所以直徑取,根據(jù)最后整體安裝尺寸取。軸段5：該軸段安裝齒輪，齒輪右邊采用套筒定位，左端采用軸肩定位，取軸段直徑。已知輪轂寬度為，為了是套筒端面可靠的壓緊齒輪，軸段長度應(yīng)略短與齒輪輪轂孔的寬度，因此長度取。軸段6：這一段軸的直徑與軸段1的直徑應(yīng)該取, 在這里選用圓錐滾子軸承，軸承型號為32911， ，所以，。 （5） 合成M ， 圖3-6軸3的計(jì)算圖 （6）校核軸的強(qiáng)度由于材料為20CrMnTi鋼，則軸的應(yīng)力在計(jì)算時(shí)需要滿足條件，經(jīng)過計(jì)算軸的應(yīng)力可以看出軸滿足強(qiáng)度要求條件。軸4的檢驗(yàn)與軸3的原理相同，就不再逐一檢驗(yàn)。3.4 軸承壽命的校核計(jì)算一般軸承的使用壽命在國際上的標(biāo)準(zhǔn)大約要在10000h30000h。在較為正常的作業(yè)環(huán)境下是可以滿足要求，但是由于采煤機(jī)相對于其他機(jī)械比較不同，工作的環(huán)境極其惡劣，在工作過程中還要時(shí)不時(shí)的遭受到附加載荷，這樣長此以往會(huì)對采煤機(jī)上的各個(gè)部件造成一定成熟上的損壞。為了能夠讓軸承有一定的使用時(shí)間，使用時(shí)比較安全可靠，可以選取小一點(diǎn)的軸承使用壽命，在這里選取11000h。軸承的壽命計(jì)算見（3-10）。 （3-10 ） 3.4.1 軸1處軸承壽命的校核依據(jù)前面設(shè)計(jì)時(shí)采用的軸承類型來校核軸承的壽命。因?yàn)槭菆A錐滾子球軸承，它不僅僅要承受來自徑向上的載荷，還有承受來自軸向上的載荷。要看軸上的軸承壽命，需要計(jì)算當(dāng)量載荷，見（3-11）。 （3-11） 支反力 ， ，軸向力軸向載荷當(dāng)量動(dòng)載荷,將已知數(shù)據(jù)代入（3-11），得， ,將已知數(shù)據(jù)代入式（3-11），得，軸承壽命 因?yàn)樯厦娴臄?shù)據(jù)顯示的是是大于的，所以計(jì)算的話按照的數(shù)據(jù)來計(jì)算，經(jīng)過查閱圖書可以知道，=1.00, =1.1。將以上數(shù)據(jù)一起代入式（3-10），得通過上述的計(jì)算結(jié)果數(shù)據(jù)顯示可以知道，上面選擇的軸承壽命是大于設(shè)計(jì)時(shí)壽命，因此軸承的類型應(yīng)該在這里確定。其他軸承的檢查方法應(yīng)該和上面的步驟一樣，就不逐一再次檢驗(yàn)。3.5 鍵的強(qiáng)度校核3.5.1 軸2上的鍵強(qiáng)度校核擠壓公式見（3-12）。 （3-12）首先在鍵的類型選定普通平鍵，它的尺寸為32100。其次要對鍵的擠壓強(qiáng)度進(jìn)行驗(yàn)算，其條件見式（3-12） 根據(jù)第三章的計(jì)算可以得出數(shù)據(jù)結(jié)果是軸2的轉(zhuǎn)距是181.91N.mm，d=120mm，b=32mm，h=18mm，l=100mm，把以上數(shù)據(jù)代入（3-12），得，所以選擇的普通平鍵滿足擠壓強(qiáng)度要求，軸3和軸4鍵強(qiáng)度校核方法同上，就不再次一一檢驗(yàn)。344 刮板輸送機(jī)的安裝、運(yùn)轉(zhuǎn)、維護(hù)4.1 刮板輸送機(jī)的安裝對于刮板輸送機(jī)的總要求是：三平、三直、一穩(wěn)、二齊全、一不漏，兩不得的標(biāo)準(zhǔn)。4.2 刮板輸送機(jī)的運(yùn)轉(zhuǎn)（1） 試運(yùn)轉(zhuǎn)地面試運(yùn)轉(zhuǎn)井下試運(yùn)轉(zhuǎn)（2） 運(yùn)轉(zhuǎn)注意事項(xiàng)啟動(dòng)順序機(jī)道浮煤量推移溜槽工作開始和結(jié)束前的空轉(zhuǎn)運(yùn)行4.3 刮板輸送機(jī)的維護(hù)為了可以讓日常的安全運(yùn)行操作，必須定期檢查維護(hù)設(shè)備，實(shí)行以下檢查制度（1） 每班檢查（2） 每日檢查（3） 每周檢查與維修（4） 每月檢查維修與保養(yǎng)結(jié)論根據(jù)市場需求，確定本次設(shè)計(jì)的中雙鏈刮板輸送機(jī)主要技術(shù)參數(shù)如下：（1） 生產(chǎn)能力：1000t/h （2） 刮板速度可調(diào)（參考）：0.8m/s，（3） 中部槽寬度：960mm（4） 參考總體長度：4000mm（5） 鏈條規(guī)格：圓環(huán)鏈（6） 卸載方式：端卸式（7） 中部槽形式：E型槽（8） 減速器：圓錐-圓柱齒輪的三級減速器（9） 電動(dòng)機(jī)：防爆異步電動(dòng)機(jī)YB2-160M-4（10） 液力耦合器：限矩形液力耦合器YOX206D考慮所選配置的安裝尺寸及其內(nèi)部的一些配置要求，校核軸的強(qiáng)度、軸承壽命、鍵的強(qiáng)度使其滿足設(shè)計(jì)的使用要求。由于個(gè)人實(shí)踐經(jīng)驗(yàn)不足，能力有限，通過對原有資料文獻(xiàn)的基礎(chǔ)上添加了自己的想法所以在此次設(shè)計(jì)中仍存在一些不足。如三級減速器的設(shè)計(jì)方面還需要進(jìn)一步的完善和改進(jìn)。隨著煤礦冶金行業(yè)的需求越來越多，刮板輸送機(jī)的應(yīng)用范圍也越來越廣泛，在以后的設(shè)計(jì)中還需要更深次的研究。致謝在畢業(yè)設(shè)計(jì)快要結(jié)束的時(shí)候，我懷著感恩的心對丁明老師所帶給我的無私幫助表示由衷的感謝。在此次設(shè)計(jì)過程中老師通過聽取我們每周開會(huì)上臺(tái)演講的方式來匯報(bào)自己每周完成畢業(yè)設(shè)計(jì)的情況后，指出我自身方向上存在的錯(cuò)誤的觀點(diǎn)方向，然后提出正確的方向來指導(dǎo)我一步一步完成后續(xù)的相關(guān)工作。我在我做這份設(shè)計(jì)的過程中體會(huì)到了老師深怕我們的知識(shí)不牢固，在我們的身上花費(fèi)了很大的耐心。不斷地糾正很小的錯(cuò)誤，哪怕是一個(gè)標(biāo)點(diǎn)符號的問題，感覺到了老師希望他帶過的每一位學(xué)生都能順利完成學(xué)業(yè)。最后，想在這里對老師表達(dá)跟隨他五個(gè)多月時(shí)間以來的感謝之情，能作為他的畢業(yè)指導(dǎo)學(xué)生的我感到非常榮幸，非常幸福。參考文獻(xiàn)1洪曉華.礦井運(yùn)輸提升M.徐州:中國礦業(yè)大學(xué)出版社,2005.2程志紅.機(jī)械設(shè)計(jì)M.南京:東南大學(xué)出版社.2006.6.3吳宗澤.機(jī)械零件設(shè)計(jì)手冊M.機(jī)械工業(yè)出版社,2004.4成大先.機(jī)械設(shè)計(jì)手冊M.化學(xué)工業(yè)出版社,20045段嗣福.弧齒錐齒輪M.徐州:中國礦業(yè)大學(xué)出版社,1988.6王洪欣.機(jī)械設(shè)計(jì)工程學(xué)M.徐州:中國礦業(yè)大學(xué)出版社,2001.7劉鴻文.簡明材料力學(xué)M.高等教育出版社,1997.8卜炎.機(jī)械傳動(dòng)裝置設(shè)計(jì)手冊M.機(jī)械工業(yè)出版社,1999.9吳宗澤.羅圣國.機(jī)械設(shè)計(jì)課程設(shè)計(jì)手冊M.高等教育出版社,2006.10吳宗澤.機(jī)械設(shè)計(jì)實(shí)用手冊M.化學(xué)工業(yè)出版社,2003.11王騰,夏護(hù)國.重型刮板輸送機(jī)驅(qū)動(dòng)方式比較分析J.煤炭科學(xué)技術(shù),2013,41(09):154-158+162.12何柏巖,孫陽輝,聶銳,李國平.礦用刮板輸送機(jī)圓環(huán)鏈傳動(dòng)系統(tǒng)動(dòng)力學(xué)行為研究J.機(jī)械工程學(xué)報(bào),2012,48(17):50-5.13黃學(xué)群,唐敬麟,欒桂鵬.運(yùn)輸機(jī)械選型設(shè)計(jì)手冊M.北京:化學(xué)工業(yè)出版社.2012.14GuoSheng,LiuJian,LiZhiRen,etal.ExperimentalresearchonairfilmformationbehaviorofaircushionbeltconveyorwithstableloadJ.ScienceChina,2013,56(6):1424-1434.15YongcunGuo.OptimizationandexperimentalstudyoftransportsectionlateralpressureofpipebeltconveyorJ.AdvancedPowderTechnology,2016,27(4):1318-1324. 35systems. assessing the example of three tractors of the same category, which are exploited in climatic and soil conditions 1. Introduction for agricultural agricultural recognized careful technical, predicting ofcropproduction.Nowadays,theexistingmathematicaloptimiza- tion methods, supported by the high-performance computers, can efficiently resolve the optimization problems (Dette Duffy et al., 1994; Mileusnic, 2007; etc.). The formation of an optimal technical system in order to produce cheaper food, highly impacted reliability of tractors, its maintainability, and the functionality of the system. rounding conditions. Although in the same spirit, some authors have defined effectiveness somewhat differently. In (Ebramhimipour maintainabilityascapacityofthe systemforpreventionandfindingfailuresanddamages,forrenewing operating ability and functionality through technical attending and repairs; and functionality as the degree of fulfilling the functional requirements, namely the adjustment to environment, or more pre- cisely to the conditions in which the system operates. In the case of monitoring reliability and maintainability it is common to monitor the time picture of state (Fig. 1) according to their working conditions is obtained. The model can be used as cri- teria for decision making related to any procedure in purchasing, operation or maintenance of the system, for prediction of repair and maintenance costs. Quality and functionality of the proposed model is shown in effectiveness determination of agricultural machinery, precisely tractors. R. Miodragovic et al./Expert Systems with Applications 39 (2012) 89408946 8941 which the functions of reliability and maintainability can be deter- mined, as well as the mean time in operation and the mean time in failure. The main problem that occurs in forming the time picture of state is data monitoring and recording. In real conditions the ma- chines should be connected to information system which would precisely record each failure, duration and procedure of repair. This is usually expensive and improvised monitoring of the machine performance, namely of its shut downs, is imprecise. Moreover, statistical data processing provided by the time picture of the state requires that all machines work under equal conditions, which is difficult to achieve. As for the functionality of the technical system, there is no common way for its measuring and quantification. This is the reason why in this paper, in order to assess the effectiveness, expertise judgments of the employed in the working process of the analyzed machines will be used. Application of expertise judgments has been largely used in literature, primarily for data processing and the assessment of the technical systems in terms of: risk (Li Wang, Yang, Tanasijevic, Ivezic, Ignjatovic, Zadeh, 1996). Application of fuzzy sets today represents one of the most frequently used tools for solving the problems in various areas of optimization (Huang, Gu, Liebowitz, 1988) in general is also used for solving the optimizations problems from area of agro machinery. In article (Rohani, Abbaspour-Fard, and fuzzy composition of men- tioned indicators into one synthesized. Fuzzy proposition is pro- cedure for representing the statement that includes linguistic variables based on available information about considered techni- cal system. In that sense it is necessary to define the names of lin- guistic variables that represent different grades of effectiveness of considered technical system and define the fuzzy sets that describe the mentioned variables. Composition is a model that provides structure of indicators influences to the effectiveness performance. 2.1. Fuzzy model of problem solving The first step in the creation of fuzzy model for effectiveness (E) assessment is defining linguistic variables related to itself and to reliability (R), maintainability (M) and functionality (F). Regarding number of linguistic variables, it can be found that seven is the maximal number of rationally recognizable expressions that hu- man can simultaneously identify (Wang et al., 1995). However, for identification of considered characteristics even the smaller number of variables can be useful because flexibility of fuzzy sets to include transition phenomena as experts judgments commonly is (Ivezic et al., 2008). According to the above, five linguistic vari- ables for representing effectiveness performances are included: poor, adequate, average, good and excellent. Form of these linguis- tic variables is given as appropriate triangular fuzzy sets (Klir .;l 5 R ; l M l 1 M ; .;l 5 M ; l F l 1 F ; .;l 5 F 1 In the next step, maxmin composition is performed on them. Max min composition, also called pessimistic, is often used in fuzzy alge- bra as a synthesis model (Ivezic et al., 2008; Tanasijevic et al., 2011; Wang et al., 1995; Wang 2000). The idea is to make overall assess- ment (E) equal to the partial virtual representative assessment. This assessment is identified as the best possible one between the worst partial grades expected (R, M or F). It can be concluded that all elements of (R, M and F) that make the E have equal influence on E, so that maxmin composition will be used, which in parallel way treats the partial ones onto the h time of planned shut down due to preventive maintenance. 1995) and OR R M F If we tions that is (according to Fig. 2): with 39 (2012) 89408946 Further, for each outcome its values are calculated (X c ). The outcome which would suit the combination c, it would be calcu- lated following the equations: X c P R;M;E j hi c 3 3 Finally, all of these outcomes are treated with maxmin composi- tion, as follows: (i) For each outcome search for the MINimum value of l R,M,F in vector E c (2). The minimum which would suit the combina- tion o, it would be calculated following the equations: MIN 0 minfl j1;.;5 R ;l j1;.;5 M .;l j1;.;5 F g;for all o 1toO 4 (ii) Outcomes are grouped according to their values X c (3), namely the size of j. (iii) Find the MAXimum between previously identified mini- mums (i) for each group (ii) of outcomes. The maximum which would suit value of j, would be calculated following the equations: MAX j maxfMIN o g; for every j 5 E assessment of technical system is obtained in the form: l E This expression (Fig. 2 tion of to fuzzy cedure (d) between the E which d i E j ;H take into account only values if l j1;.;5 R;M;F 0, we get combina- are named outcomes (o =1toO, where O # C). in the process of synthesis, are also used. Precisely, if we look at three partial indicators, namely their membership function (1), it is possible to make C = j 3 =5 3 combina- tions of their membership functions. Each of these combinations represents one possible synthesis effectiveness assessment (E). E l j1;.;5 ;l j1;.;5 ; .;l j1;2;.5 hi ; for all c 1toC 2 maxmin compositions which by using operators AND provide an advantage to certain elements over the others synthetic indicator. In literature (Ivezic et al., 2008; Wang et al., Fig. 2. Effectiveness fuzzy sets. 8942 R. Miodragovic et al./Expert Systems MAX j1 ; .;MAX j5 l 1 E ; .;l 5 E 6 (6) is necessary to map back to the E fuzzy sets ). Best-fit (Wang et al., 1995), method is used for transforma- E description (6) to form that defines grade of membership sets: poor, adequate, average, good and excellent. This pro- is recognized as identification. Best-fit method uses distance E obtained by maxmin composition (6) and each of expressions (according to Fig. 2), to represent the degree to E is confirmed to each of fuzzy sets of effectiveness (Fig. 2). i X 5 j1 l j E C0l j H j 2 v u u t ; j 1; .;5;H i fexcellent;goodaverage;adequate;poorg7 E i fb i1 ;poor;b i2 ;adequate;b i3 ;good; b i4 ;average;b i5 ;excellentg 10 3. An illustrative example As an illustrative example of evaluation of agriculture machin- ery effectiveness, the comparative analysis of three tractors A 1 B 2 , and C 2 is given in this article. In tractor A a 7.146 l engine LO4V TCD 2013 is installed. Thanks to the reserves of torque from 35%, the tractor is able to meet all the requirements expected in the worst performing farming oper- ations in agriculture. Total tractor mass is 16,000 kg. According to OECD (CODE II) report maximum power measured at the PTO shaft is 243 kW at 2200 rpm with specific fuel consumption of 198 g/kW h (ECE-R24). Maximum engine torque is 1482 Nm at en- gine regime of 1450 rpm. Transmission gear is vario continious transmision. Linkage mechanism is a Category II/III with lifting force of 11,800 daN. In tractors B 2 and C 2 8.134 l engine 6081HRW37 JD is installed, with reserve torque of 40%, and this tractor was able to meet all the requirements expected in the worst performance of the farming operations in agriculture. Total tractor weight is 14,000 kg. Accord- ing to OECD (CODE II) report maximum power measured at the PTO shaft is 217 kW at 2002 rpm with specific fuel consumption of 193 g/kW h (ECE-R24). Maximum torque is 1320 Nm at engine revs of 1400 rpm. Transmission is AutoPower. Linkage mechanism is a Category II/III with lifting force of 10,790 daN. Both models have electronically controlled tractor engine and fuel supply system that meets the regulations on emissions. From the submitted technical characteristics of the tractor A, B and C it is seen that all three tractors are fully functional for l exc. = (0,0,0,0.25,1); l good = (0,0,0.25,1,0.25); l aver. = (0,0.25,1,0.25,0); l adeq. = (0.25,1,0.25,0,0); l poor = (1,0.25,0,0,0). The closer l E (6) is to the ith linguistic variable, the smaller d i is. Distance d i is equal to zero, if l E (6) is just the same as the ith expression in terms of the membership functions. In such a case, E should not be evaluated to other expressions at all, due to the exclusiveness of these expressions. Suppose d imin (i =1,.,5) is the smallest among the obtained distances for E j and leta 1 ,.,a 5 represent the reciprocals of the rel- ative distances (which is calculated as the ratio between corres- ponding distance d i (7) and the mentioned values d imin ). Then, a i can be defined as follows: a i 1 d i =d imin ; i 1; .;5 8 If d i = 0 it follows that a i = 1 and the others are equal to zero. Then, a i can be normalized by: b i a j P 5 m1 a im ; i 1; .;5 X 5 i1 b i 1 9 Each b i represents the extent to which E belongs to the ith defined E expressions. It can be noted that if E i completely belongs to the ith expression then b i is equal to 1 and the others are equal to 0. Thus b j could be viewed as a degree of confidence that E i belongs to the ith E expressions. Final expression for E performance at the level of tech- nical system, have been obtained in the form (10) where Applications 1 Tractor Fendt Vario 936. 2 Tractor John Deere 8520. performing difficult operations for different technologies of agri- cultural production. Tractors B and C have the same technical char- acteristics, and practice is the same type and model, except that the tractor B entered into operation in May 2007, a tractor C in June 2007. A tractor on the experimental farm, which is the technical documentation for the base model, comes into operation in July 2009. The main task of maintaining agricultural techniques is to provide functionality and reliability of machines. Maintenance of all three tractors is done by machine shop owned by the user up- grade option. Ten engineers (analysts) working on maintenance and opera- tion of tractors were interviewed. Their evaluation of R, D and F are given in Table 1. First, the effectiveness of tractor A is calculated. It can be seen that the reliability was assessed as excellent by six out of ten ana- lysts (6/10 = 0.6), as average by three (0.3) and as good by one (0.1). In this way the assessment R is obtained in the form (11): R 0:6=exc; 0:3=good; 0:1=aver; 0=adeq; 0=poor11 In the same way the assessments for M and F are obtained: M 0:4=exc; 0:4=good; 0:2=aver; 0=adeq; 0=poor F 0:5=exc; 0:5=good; 0=aver; 0=adeq; 0=poor In the next step, these assessments are mapped on fuzzy sets (Fig. 1) in order to obtain assessment in the form (1). For example, Reliabil- ity in this example is determined as (11), where it is to linguistic variable excellent joined weight 0.6. Thereby, fuzzy set excellent is defined as: R exc = (1/0, 2/0, 3/0, 4/0.25, 5/1.0) (according to Fig. 1). In this way the specific values of fuzzy set excellent R exc0.6 = (1/(0 C2 0.6), 2/(0 C2 0.6), 3/(0 C2 0.6), 4/(0.25 C2 0.6), 5/(1.0 C2 0.6) are obtained. The remaining four linguistic variables are treated in the same way. In the end for each j =1,.,5 specific membership functions (last row, Table 2) are added into the final fuzzy form (1) of tractor A reliability: l RA 0;0:025;0:175;0:475;0:675 In the same way, based on the questionnaire (Table 1) values for maintainability and functionality are obtained: l MA 0;0:05;0:3;0:55;0:5; l FA 0;0;0:125;0:625;0:62512 These fuzzificated assessments (11) and (12) are necessary to syn- thesize into assessment of effectiveness, using maxmin logics. In this case it is possible to make C =5 3 = 125 combinations, out of which the 48 outcomes. First outcome would be for combination 2-2-3: E 2-2-3 = 0.025,0.05,0.125, where is X 2-2-3 = (2 + 2 + 3)/3 = 2 (rounded as integer). Smallest value among the membership func- tions of this outcome is 0.025. Other outcomes and corresponding values of X c are shown in Table 3. All these outcomes can be grouped around sizes X = 2, 3, 4 and 5. For example, for outcome X = 5 it can be written: E 4C05C05 0:475;0:5;0:625C138;E 5C04C05 0:675;0:55;0:625C138;E 5C05C04 0:675;0:5;0:625C138;E 5C05C05 0:675;0:5;0:625C138 Further, for each of them, minimum between membership function is sought: Table 1 Results of questionnaire. Average x x xx x xx x R. Miodragovic et al./Expert Systems with Applications 39 (2012) 89408946 8943 Analyst Linguistic variables Tractor A Tractor B Excellent Good Average Adequate Poor Excellent Good 1R x x Mx x Fxxx 2R x Mx x Fx 3R x x Mx Fx 4R x x Mx Fx x 5R x x Mx Fxxx 6R x x Mx Fx x 7R x Mx Fx 8R x x Mx x Fx x 9R x x Mx x Fx x 10 R x x Mx x Fx x Tractor C Adequate Poor Excellent Good Average Adequate Poor x x x x x x x x x x x xx x x x x x x x x x with Table 2 Calculation of specific values of fuzzy sets. 12345 0.6/exc. 0 C2 0.6 0 C2 0.6 0 C2 0.6 0.25 C2 0.6 1.0 C2 0.6 0.3/good 0 C2 0.3 0 C2 0.3 0.25 C2 0.3 1.0 C2 0.3 0.25 C2 0.3 8944 R. Miodragovic et al./Expert Systems MINE 4C05C05 minf0:475;0:5;0:625g0:475;MINE 5C04C05 0:55;MINE 5C05C04 0:5;MINE 5C05C05 0:5 Between these minimums, in the end it seeks maximum: MAXX d5 maxf0:475;0:55;0:5;0:5g0:55 Also for other values: X: MAX X =2 = 0.025; MAX X =3 = 0.175; MAX X =4 = 0.55 (Table 1.) 0.1/aver. 0 C2 0.1 0.25 C2 0.1 1.0 C2 0.1 0.25 C2 0.1 0 C2 0.1 0/adeq. 0.25 C2 0 1.0 C2 0 0.25 C2 00C2 00C2 0 0/poor 1.0 C2 0 0.25 C2 00C2 C2 C2 0 P R 0 0.025 0.175 0.475 0.675 Table 3 Structure of MAXMIN composition. Comb. X l MIN 2345 2-2-3 2 0.025,0.05,0.125 0.025 2-2-4 3 0.025,0.05,0.625 0.025 2-2-5 3 0.025,0.05,0.625 0.025 2-3-3 3 0.025,0.3,0.125 0.025 2-3-4 3 0.025,0.3,0.625 0.025 2-3-5 3 0.025,0.3,0.625 0.025 2-4-3 3 0.025,0.55,0.125 0.025 2-4-4 3 0.025,0.55,0.625 0.025 2-4-5 4 0.025,0.55,0.625 0.025 2-5-3 3 0.025,0.5,0.125 0.025 2-5-4 4 0.025,0.5,0.625 0.025 2-5-5 4 0.025,0.5,0.625 0.025 3-2-3 3 0.175,0.05,0.125 0.05 3-2-4 3 0.175,0.05,0.625 0.05 3-2-5 3 0.175,0.05,0.625 0.05 3-3-3 3 0.175,0.3,0.125 0.125 3-3-4 3 0.175,0.3,0.625 0.175 3-3-5 4 0.175,0.3,0.625 0 0.175 3-4-3 3 0.175,0.55,0.125 0.125 3-4-4 4 0.175,0.55,0.625 0.175 3-4-5 4 0.175,0.55,0.625 0.175 3-5-3 4 0.175,0.5,0.125 0.125 3-5-4 4 0.175,0.5,0.625 0.175 3-5-5 4 0.175,0.5,0.625 0.175 4-2-3 3 0.475,0.05,0.125 0.05 4-2-4 3 0.475,0.05,0.625 0.05 4-2-5 4 0.475,0.05,0.625 0.05 4-3-3 3 0.475,0.3,0.125 0.125 4-3-4 4 0.475,0.3,0.625 0.3 4-3-5 4 0.475,0.3,0.625 0.3 4-4-3 4 0.475,0.55,0.125 0.125 4-4-4 4 0.475,0.55,0.625 0.475 4-4-5 4 0.475,0.55,0.625 0.475 4-5-3 4 0.475,0.5,0.125 0.125 4-5-4 4 0.475,0.5,0.625 0.475 4-5-5 5 0.475,0.5,0.625 0.475 5-2-3 3 0.675,0.05,0.125 0.05 5-2-4 4 0.675,0.05,0.625 0.05 5-2-5 4 0.675,0.05,0.625 0.05 5-3-3 4 0.675,0.3,0.125 0.125 5-3-4 4 0.675,0.3,0.625 0.3 5-3-5 4 0.675,0.3,0.625 0.3 5-4-3 4 0.675,0.55,0.125 0.125 5-4-4 4 0.675,0.55,0.625 0.55 5-4-5 5 0.675,0.55,0.625 0.55 5-5-3 4 0.675,0.5,0.125 0.125 5-5-4 5 0.675,0.5,0.625 0.5 5-5-5 5 0.675,0.5,0.625 0.5 MAX 0.025 0.175 0.55 0.55 Finally, we get expression for membership function of effective- ness of tractor A: l EA 0;0:025;0:175;0:55;0:55 Best-fit method (79) and proposed E fuzzy set (Fig. 1) give the final effectiveness assessment for the tractor A: d 1 E;exc X 5 j1 l j E C0l j exc 2 v u u t 0C00 2 0:025C00 2 0:175C00 2 0:55C00:25 2 0:55C01 2 q 0:56899 where is : l E 0;0:025;0:175;0:55;0:55 l exc 0;0;0;0:25;1 For other fuzzy sets: d 2 (E, good) = 0.54658, d 3 (E, aver) = 1.06007, d 4 (E, adeq) = 1.27426, d 5 (E, poor) = 1.29856. for d min d 2 : a 1 1 d 1 =d 2 1 0:56899=0:54658 0:96061; a 2 1:00000;a 3 0:51561;a 4 0:42894;a 5 0:42091: b 1 a 1 P 5 i1 a i 0:96901 0:96901 1 0:51561 0:42894 0:42091 0:28881; b 2 0:30065;b 3 0:15502;b 4 0:12896;b 5 0:12655: Finally, we get the assessment of effectiveness of tractor A, in form (10): E A =(b 1 , excellent), (b 2 , good), (b 3 , average), (b 4 , ade- quate), (b 5 , poor) = (0.28881, excellent), (0.30065, good), (0.15502, average), (0.12896, adequate), (0.12655, poor) In the same way, we get the assessments for other two tractors B and C: E B = (0.23793, excellent), (0.27538, good), (0.20635, aver- age), (0.14693, adequate), (0.13342, poor) E C = (0.17507, excellent), (0.25092, good), (0.25468, aver- age), (0.17633, adequate), (0.14300, poor). Tractor A is in great extent of 0.30065 (in relation to 30 %) as- sessed as good, tractor B in great extent of 0.27538 (27.5%) as- Applications 39 (2012) 89408946 sessed as good, while tractor C is in great extent of 0.25468 (25.5%) assessed as average. It can be concluded that C is the worst, while tractor A is only somewhat better than B, especially if we see with that A is assessed as excellent in the extent of 28.8% while B in the extent of 23.8%. Effectiveness of analyzed tractors can be presented as in Fig. 3., where it can be more clearly seen that tractor A has the biggest effectiveness. If this assessment (E A , E B , E C ) is defuzzificated by center of mass point calculation Z (Bowles if calculated on 10,000 moto-hours, Fig. 3. Relationship of effectiveness of observed tractors. R. Miodragovic et al./Expert Systems it would spend in work 9244 moto-hours. As of the tractor B, out of 10,004 available moto-hours, it spent 9069 moto-hours in work, and tractor C out of 9981 available moto-hours spent 9045 in work. The experiment showed that the more reliable and efficient tractors are the less frequent are delays. In part, this initial advan- tage wiped out worse logistics of delivery of spare parts when it comes to tractor A. in 1100 moto-hours work of the tractor, due to poor logistics in maintaining hoped to eight working days, and it greatly influenced the decline in benefits of maintainability of a given tractor and thus the decline in total exploitation of the same efficiency (Internal technical documentation PKB). 4. Conclusion This paper presents a model for effectiveness assessment of technical systems, precisely agricultural machinery, based on fuzzy sets theory. Effectiveness performance has been adopted as overall indicator of systems quality of service, i.e. as entire measure of technical system availability. Reliability, maintainability and func- tionality performances have been recognized as effectiveness parameters or indicators. Linguistic form can be appointed as the References Bowles, J. B., & Pelaez, C. E. (1995). Fuzzy logic prioritization of failures in a system failure mode, effects and criticality analysis. Reliability Engineering and System Safety, 50(2), 203213. Cai, K. Y. (1996).