對輥窩眼式核桃破殼機的設(shè)計,對于,輥窩眼式,核桃,破殼機,設(shè)計 對輥窩眼式核桃破殼機的設(shè)計姓名：談向明專業(yè)：農(nóng)業(yè)機械化及其自動化學院：機械電氣化工程學院指導老師：蘭海鵬前言近年來，隨著經(jīng)濟發(fā)展和人民生活水平的提高，核桃的價值與功能進一步被世人認識和重視，國內(nèi)外市場對核桃及其加工品的需求量日益增長。旺盛的國內(nèi)外市場需求為我國核桃產(chǎn)業(yè)提供了廣闊的發(fā)展空間，也對我國核桃產(chǎn)品加工及質(zhì)量安全提出了更高的要求。目前存在的問題 由于核桃品種繁雜，尺寸差異較大、形狀不規(guī)則、核仁間隙小，所以核桃的破殼取仁難度較大。破殼后還需要進行核仁分離，鑒于核仁密度相差不大，加之碎殼、碎仁上有許多毛刺，所以核仁分離也有相當難度。這是目前核桃破殼技術(shù)方面存在的主要問題國內(nèi)外研究現(xiàn)狀及分析我國堅果破殼機具發(fā)展緩慢，遠遠落后于種植業(yè)的發(fā)展，在一些生產(chǎn)應(yīng)用的機具中存在如下幾個問題（1）破殼率低（2）果仁完整性差（3）通用性差（4）損失率搞（5）機具性能不穩(wěn)定，適應(yīng)性差目前核桃破殼的幾種方法的利弊目前，核桃破殼取仁方法有離心碰撞式破殼法、化學腐蝕法、真空破殼取仁法、超聲波破殼法和定間隙擠壓破殼法。離心碰撞方法碎仁太多，所以應(yīng)用很少；化學腐蝕方法由于在實際操作中不好控制，仁易受到腐蝕，處理不好還會對環(huán)境造成污染；真空破殼和超聲波破殼方法設(shè)備昂貴，破殼成本高，且破殼效果不夠理想；定間隙擠壓破殼方法值得探索。核桃破殼裝置是核桃破殼取仁機的核心裝置。機械剝殼常用方法有借助粗糙表面碾搓作用的碾搓剝殼、借助撞擊作用撞擊剝殼、利用剪切作用的剪切剝殼和利用成對軋輥擠壓作用的擠壓剝殼。常見的破殼裝置有圓盤剝殼裝置、齒輥剝殼裝置、離心剝殼裝置、錘擊式剝殼裝置、軋輥式剝殼裝置、對輥窩眼式開口裝置、沖壓式破殼裝置、核桃鋸口破殼裝置、核桃破殼挖核裝置及平板擠壓式破殼裝置。由于核桃品種繁雜、尺寸差異較大、形狀不規(guī)則、殼仁間隙小，所以核桃的破殼取仁難度較大。破殼后還需進行殼仁分離,鑒于殼仁密度相差不大(約為04g/cm)，加之碎殼、碎仁上有許多毛刺，所以殼仁分離也有相當難度。解決以上難題的方法就是將破殼取仁分解為分級、導向、擠壓破殼(多點)、殼仁分離四部分，逐一加以解決。方案的選取 針對核桃破殼過程中的各種問題，同過查閱資料以及對以上各種核桃破殼機的了解。確定選用對輥窩眼式核桃破殼機進行設(shè)計和研究?？尚行苑治鰧伕C眼式核桃破殼機已經(jīng)是一種成熟的核桃破殼機，所以在大的方向上沒問題。由于本人水平有限所以沒有加核桃分級裝置，直接用分選好的核桃進行擠壓破殼。大大降低了設(shè)計難度，使的設(shè)計能夠順利進行。設(shè)計方案分選好的核桃從進料口喂入，由于進料口上寬下窄，窄的部分剛好能通過一排直徑為30mm左右的核桃進入擠壓輥。電機通過帶傳動帶動擠壓輥轉(zhuǎn)動進行破殼，破殼后的核桃掉入出料槽從出料口送出?；緲?gòu)架核心部件核心部件的設(shè)計核心部件是擠壓輥，它的表面分布著很多核桃大小的窩眼。窩眼的加工是一項很復雜的工作，工藝要求很高，所以我們可以借工程師設(shè)計好的輥拿過來用。設(shè)計的總體評價本課題為繞核桃破殼，簡單介紹了對輥窩眼式核桃破殼機的工作原理和過程。本課題整體簡單明了，設(shè)備在實際操作中也很簡單方便，并且效率很高。在核桃破殼過程中壓碎的情況較少。缺點是小尺寸的核桃容易漏掉破殼不徹底。感謝各位老師的批評和指正 12 屆畢業(yè)論文 對輥窩眼式核桃破殼機的設(shè)計 設(shè)計說明書 學生姓名 學 號 8031208129 所屬學院 機械電氣化工程學院 專 業(yè) 農(nóng)業(yè)機械化及其自動化 班 級 12-1 指導教師 日 期 2012.06 塔里木大學教務(wù)處制 前 言 核桃是林果業(yè)中最具市場競爭力的特色果品，也是近年來南疆林果業(yè)中發(fā)展速度最快的樹種。隨著核桃產(chǎn)量的日益增加，市場上對核桃深加工產(chǎn)品的需求也越來越迫切，將核桃破殼后深加工不僅可以增加核桃的附加值，而且還能帶動整個核桃產(chǎn)業(yè)的發(fā)展。核桃破殼是核桃深加工中必須首先解決的重要工序。 核桃是主要的名特優(yōu)林果樹種之一，種植歷史悠久，種質(zhì)資源豐富。隨著西部大開發(fā)戰(zhàn)略的貫徹落實，自治區(qū)將農(nóng)業(yè)產(chǎn)業(yè)結(jié)構(gòu)調(diào)整的著力點，放在提高農(nóng)產(chǎn)品的質(zhì)量、效益和產(chǎn)品競爭力上，將林果業(yè)作為農(nóng)業(yè)增效、農(nóng)村經(jīng)濟發(fā)展、農(nóng)民增收的支柱產(chǎn)業(yè)培育，使核桃生產(chǎn)向著基地化、規(guī)?；?、產(chǎn)業(yè)化方向發(fā)展。核桃是林果業(yè)中最具市場競爭力的特色果品，也是近年來南疆林果業(yè)中發(fā)展速度最快的樹種。 據(jù)統(tǒng)計，2009 年全疆核桃種植面積已達 300 萬畝，比 2000 年（40 萬畝）增加了 260萬畝，平均每年增加 24.5 萬畝核桃面積。約占全疆林果業(yè)總面積（1600 萬畝）的近五分之一，約占全國核桃栽培總面積(3000 萬畝)的十分之一，為第二大果樹。全疆300 萬畝核桃，其中投產(chǎn)面積約 100 萬畝，年產(chǎn)核桃堅果 8 萬噸，總產(chǎn)值約 20 億元。核桃年產(chǎn)值位于自治區(qū)干、堅果樹種之首，僅次于葡萄、杏，名列全疆林果樹種年產(chǎn)值第三位。 但是我們不能只靠賣原料來增收，而要走農(nóng)產(chǎn)品深加工，一是取仁或取仁后加工飲料等，二是制油來提高核桃的附加值使農(nóng)民增收。核桃破殼取仁是核桃深加工的第一步，必須首先解決。破殼后的核桃殼有著廣泛的用途，它可以制成活性碳、過濾器中的濾料、堵漏材料等等。核桃破殼取仁將大大提高核桃的附加值。 目 錄 1緒論 1 1.1選題的目的和意義 1 1.2本課題所涉及的問題及國內(nèi)（外）研究現(xiàn)狀及分析 1 2.設(shè)計方案的選擇 2 2.1研究方案的確定 2 2.2核桃進料口的設(shè)計 3 2.3核桃破殼部分的設(shè)計 3 2.4軸的設(shè)計 4 2.4.1軸的設(shè)計 4 2.4.2軸的校核 5 2.4.3軸系零件的定位 6 2.5 軸承的選擇 7 2.6 鍵聯(lián)結(jié)的選擇與校核 8 2.6.1鍵的選擇 8 2.6.2校核鍵聯(lián)接的強度 8 2.7軸承端蓋的設(shè)計 8 3帶輪的選擇 9 3.1帶輪的結(jié)構(gòu)設(shè)計 9 4電動機的選擇 9 5電機的尺寸及安裝 10 5.1電機的安裝 10 5.2電機的調(diào)整 10 6 固定支撐部分的設(shè)計 10 6.1機架的設(shè)計 10 7.裝配質(zhì)量 11 8.總結(jié) 11 塔里木大學畢業(yè)設(shè)計 1緒論 1.1選題的目的和意義 近年來，隨著經(jīng)濟發(fā)展和人民生活水平的提高，核桃的價值與功能進一步被世人認識和重視，國內(nèi)外市場對核桃及其加工品的需求量日益增長。旺盛的國內(nèi)外市場需求為我國核桃產(chǎn)業(yè)提供了廣闊的發(fā)展空間，也對我國核桃產(chǎn)品加工及質(zhì)量安全提出了更高的要求。但由于核桃品種繁雜，尺寸差異較大、形狀不規(guī)則、核仁間隙小，所以核桃的破殼取仁難度較大。破殼后還需要進行核仁分離，鑒于核仁密度相差不大，加之碎殼、碎仁上有許多毛刺，所以核仁分離也有相當難度。這是目前核桃破殼技術(shù)方面存在的主要問題[1]。 解決以上難度的方法就是將破殼取仁分解為分級、導向、擠壓破殼（多點）、核仁分離四部分，逐一加以解決。 國外的核桃加工業(yè)已經(jīng)相當成熟，并且形成了一定的規(guī)模。在美國、澳大利亞等發(fā)達國家，核桃的采收、脫青皮、清洗、烘干以及破殼和殼仁分離等工序已完全實現(xiàn)J，機械化。我國核桃采后處理技術(shù)比較落后，在核桃脫青皮、破殼、殼仁分離等加工關(guān)鍵環(huán)節(jié)和設(shè)備成套性方面處于空白，嚴重制約了核桃油、核桃蛋白粉和核桃果汁等產(chǎn)品的精深加工。為提高我國核桃產(chǎn)業(yè)化加工技術(shù)水平，實現(xiàn)核桃生產(chǎn)的商品化，分析研究國外先進的核桃加工技術(shù)，摸索出了美國核桃加工工藝和生產(chǎn)線流程，結(jié)合我國核桃生產(chǎn)實際情況，設(shè)計出適合我國的核桃加工工藝和成套設(shè)備，是我們面臨的主要問題，也是研究核桃破殼的意義所在。 1.2本課題所涉及的問題及國內(nèi)（外）研究現(xiàn)狀及分析 國外研究現(xiàn)狀及分析 目前，核桃年產(chǎn)量在20萬t以上的國家僅有中國和美國。中美兩國的核桃產(chǎn)量占世界核桃總產(chǎn)量的50％左右，而最有代表性、生產(chǎn)水平最高和市場占有份額最大的當數(shù)美國。在美國、澳大利亞以及歐洲等發(fā)達國家，核桃絕大部分都經(jīng)過機械化生產(chǎn)線進行商品化處理。采收通過機械振蕩器將核桃果實振落到地面上，再由機械將果實收集起來，運到加工廠進行脫青皮、漂洗、烘干和帶殼包裝等處理。核桃仁加工也全部機械化，通過破殼機破殼，機械、氣流分選機進行殼仁分離，然后用分色機將果仁分為深色和淺色[2]，再分為全仁和碎仁不同大小等級，最后分別包裝銷售。 目前核桃生產(chǎn)國中最有代表性、生產(chǎn)水平最高、市場占有份額最大的當數(shù)美國。美國可謂核桃生產(chǎn)上年輕而又強大的王國。美國核桃采收的機械化程度很高，先是噴灑乙烯利(一種果實催熟藥劑)，然后用振落機采收，再用脫青皮機脫皮，用清洗機清洗，用烘干機烘干、利用冷庫進行干燥處理和貯藏。如加工果仁，采用破殼機破殼，通過氣流分選機進行殼仁分離，然后用分色機將果仁分為深色和淺色，再分出全仁和碎仁，最后分別稱重包裝銷售。 國外早在20世紀60年代初，就著手研制堅果剝殼機具，至80年代初，美國、意大利、法國等已相繼推出了各種堅果剝殼機，如夏威夷果剝殼機、杏仁剝殼機等。經(jīng)過數(shù)十年的發(fā)展，堅果剝殼機具已日趨成熟，目前，正朝著機電一體化方向發(fā)展。由于美國的主栽品種只有強特勒、哈特利、希爾、維納、土萊爾、豪沃迪這 6 個，其品質(zhì)優(yōu)良，規(guī)格劃一，有利于機械化破殼，因此核桃破殼機在美國發(fā)展較早。主要的核桃破殼機類型有[3]：①Larry H. Hemry 研制的專利號為 6098530 機械式核桃破殼機。該機的主要結(jié)構(gòu)由機架、料斗、可調(diào)節(jié)定位板、破碎裝置、傳動機構(gòu)以及動力所組成。機械式核桃破殼機通過調(diào)節(jié)可調(diào)節(jié)定位板和破碎裝置間的間隙能夠適應(yīng)各類堅果的破殼。②Kenneth R. Evans 研制的專利號為 4201126 核桃破殼機。該機主要由喂料斗、輸送裝置、破殼裝置和出料口等組成。工作時，由輸送裝置把待破殼的核桃從料箱運送到破殼裝置，然后對其進行破殼。③Clarence Lloyd Warmack 和 Barry Shawn Warmack等研制的專利號為 6516714 核桃破殼機。該機主要由機架、箱體、滾筒、旋轉(zhuǎn)破殼裝置和出料口等組成。該機可以成功有效地擊打核桃將其殼仁分離。④John W. Brazil 發(fā)明的專利號為 4255855 核桃鉗。該鉗由把手、可調(diào)柱塞、夾頭、底座和固定套等組成。使用時，將核桃放置在底座上，然后通過操縱把手推動可調(diào)柱塞在固定套內(nèi)滑動，可調(diào)柱塞伸出從而使夾頭將核桃推到剛性砧底座上把核桃夾緊并破殼。⑤Michael P.Filice，Robert Lemos 和 Robert P.Baker 等研制的專利號為 5325769 核桃破殼機。該機主要由機架、喂料斗、輸送裝置、擊打裝置和傳動裝置等組成。工作時，料箱中的核桃由輸送裝置逐一運送到擊打裝置，然后由凸輪控制擊打打頭將核桃殼打破使其殼仁分離。 國內(nèi)研究現(xiàn)狀及分析 我國堅果剝殼機具發(fā)展緩慢，遠遠落后于種植業(yè)的發(fā)展，在一些生產(chǎn)應(yīng)用的機具中，存 如下幾個突出的問題，因而，難以推廣應(yīng)用[4]。 (1)剝殼率低。不少剝殼機漏剝或剝殼不完全，果仁去凈率不高，有些剝殼機剝殼率只有50%。這是堅果剝殼機推廣使用的最大障礙。 (2)損失率高。由于參數(shù)選擇不合理，造成剝殼不完全現(xiàn)象嚴重，碎仁夾帶在碎殼中難以回收而被棄除。有些機具果仁損失率高達20%。 (3)果仁完整性差。有些機具的設(shè)計，為了減少漏剝或剝殼不完全現(xiàn)象，一味追求剝殼率的提高，導致高的破碎率，從而降低了產(chǎn)品的商品價值。 (4)通用性差。一般剝殼機僅能用于某一品種堅果的剝殼作業(yè)，對于不同品種的堅果，不能通過更換主要零部件來實現(xiàn)一機多用。 (5)機具性能不穩(wěn)定，適應(yīng)性差。為某類堅果專門開發(fā)的專用機型，在該堅果品種、大小規(guī)格、外殼形狀和含水量等因素出現(xiàn)變化時，剝殼機具剝殼性能就變差。 (6)作業(yè)成本偏高。我國堅果剝殼機具尚未形成規(guī)模和系列，多數(shù)是單機制造，制造的工藝水平低、成本高、也因為通用性差，不能一機多用，使得生產(chǎn)企業(yè)設(shè)備配置的成本高，致使加工堅果的作業(yè)成本增加。 目前，核桃破殼取仁方法有離心碰撞式破殼法、化學腐蝕法、真空破殼取仁法、超聲波破殼法和定間隙擠壓破殼法。離心碰撞方法碎仁太多，所以應(yīng)用很少；化學腐蝕方法由于在實際操作中不好控制，仁易受到腐蝕，處理不好還會對環(huán)境造成污染；真空破殼和超聲波破殼方法設(shè)備昂貴，破殼成本高，且破殼效果不夠理想；定間隙擠壓破殼方法值得探索。核桃破殼裝置是核桃破殼取仁機的核心裝置。機械剝殼常用方法有借助粗糙表面碾搓作用的碾搓剝殼、借助撞擊作用撞擊剝殼、利用剪切作用的剪切剝殼和利用成對軋輥擠壓作用的擠壓剝殼。常見的破殼裝置有圓盤剝殼裝置、齒輥剝殼裝置、離心剝殼裝置、錘擊式剝殼裝置、軋輥式剝殼裝置、對輥窩眼式開口裝置、沖壓式破殼裝置、核桃鋸口破殼裝置、核桃破殼挖核裝置及平板擠壓式破殼裝置。由于核桃品種繁雜、尺寸差異較大、形狀不規(guī)則、殼仁間隙小，所以核桃的破殼取仁難度較大。破殼后還需進行殼仁分離，鑒于殼仁密度相差不大，加之碎殼、碎仁上有許多毛刺，所以殼仁分離也有相當難度。解決以上難題的方法就是將破殼取仁分解為分級、導向、擠壓破殼(多點)、殼仁分離四部分，逐一加以解決[5]。 本課題重點研究核桃破殼機的破殼部分，以改善現(xiàn)存的剝殼率低、損失率高、果仁完整性差、通用性差、機具性能不穩(wěn)定、適應(yīng)性差、作業(yè)成本偏高等問題。 2.設(shè)計方案的選擇 2.1研究方案的確定 通過查閱大量文獻資料，以及在指導老師的幫助下，確定了整個設(shè)計的大體思路。整個裝配圖由進料口、機架、擠壓裝置、傳動部分、電動機等組成。核桃由入料口進入擠壓輥破殼。 其結(jié)構(gòu)如圖2-1所示 圖2-1 核桃破殼機的結(jié)構(gòu)示意圖 2.2核桃進料口的設(shè)計 核桃進料口是一個錐形裝置，口大底小，底的大小剛好能通過分選好的一排核桃。核桃通過此裝置剛好掉入擠壓輥中進行破殼。 圖2-2 進料口示意圖 2.3核桃破殼部分的設(shè)計 其結(jié)構(gòu)示意圖如圖2-3所示： 圖2-3 核桃破殼機破殼部分的結(jié)構(gòu)示意圖 桃仁選取直徑為30mm的核桃為原料。因此本機使用于徑粒為30mm的核桃開口。根究實驗，要使核桃開口，其擠壓變形量△h=4mm。若△h＞4mm，則開口率降低；若△h＜4mm，則破碎率增加。圖2-4為核桃受輥擠壓時的狀態(tài)。D為圓柱擠壓輥的外徑，D0為窩底包絡(luò)線的直徑。為便于計算，將擠壓情況簡化為圖2-3（a）（b）。d0為核桃的的原始直徑，d1為擠壓時的尺寸。△h= d0- d1=4mm。α為導入角。根據(jù)資料[6]，要能夠正常導入進行擠壓，必須滿足α＜ψ。其中ψ味核桃與加壓滾間的摩擦角。由幾何關(guān)系知 若用摩擦角表示則為 根據(jù)實驗，核桃與擠壓輥間的摩擦角約為12°。由此可知，D0>183mm，D>183mm+45=228mm，取D=250mm。對輥中心距A=250mm。 圖2-4（a）（b）核桃的擠壓原理簡圖 2.4軸的設(shè)計 2.4.1軸的設(shè)計 設(shè)計軸長為1143mm，分為5段。其結(jié)構(gòu)示意圖如下所示 圖2-5傳動軸結(jié)構(gòu)示意圖 第一段軸與皮帶輪以及軸承連接，其直徑為25mm；第二段軸用來裝齒輪的，還需要設(shè)計一個軸肩，用來固定軸承：第三段是偏心軸，其基準直徑為36mm，偏心距為5mm。 軸的材料：軸的材料主要是碳剛和合金剛。由于碳剛比合金剛價格便宜[7]，對應(yīng)力集中的敏感性較低，同時也可以用熱處理或化學熱處理的辦法提高其耐磨性和抗疲勞強度，所以本設(shè)計采用45號剛作為軸的材料。調(diào)制處理。第三段軸軸表面淬火，增加其表面的耐磨性能。 2.4.2軸的校核 經(jīng)過分析，主軸軸的受力最大，而且軸的周向受力是主要的，因此，對該軸進行扭矩校核。軸的結(jié)構(gòu)見圖2-4 主軸轉(zhuǎn)速 根據(jù)公式 （2—1） 其中h為板的高度0.6m，g為10m/s2 t為時間 得時間t約為0.35s 取t為0.4s 既得主軸0.4s轉(zhuǎn)一圈 所以主軸轉(zhuǎn)速至少為150r/min 取其整數(shù)倍 軸的扭矩計算 電動機輸出轉(zhuǎn)矩： T== （2—2） 式中：為電動機額定功率，為電動機轉(zhuǎn)速 主軸輸入轉(zhuǎn)矩： （2—3） 為皮帶輪的傳動效率根據(jù)設(shè)計指導書參考初選 為軸承的傳動效率初選 為鏈輪的傳動效率初選 根據(jù)要求，軸要滿足下列條 軸的強度條件： （2—4） 式中：為軸的切應(yīng)力，MPa;T為轉(zhuǎn)矩，N.mm;為抗扭截面系數(shù)，;為許用扭切應(yīng)力，MPa. 表2—1常用材料的值和C值 軸的材料 Q235，20 35 45 40Cr，35SiMn 12-20 20-30 30-40 40-52 C 160-135 135-118 118-107 107-98 該軸的材料為45號鋼，則滿足強度條件，軸是安全的 軸傳遞的轉(zhuǎn)矩 （2—5） （2—6） 軸的剛度計算 （2—7） 式中：T為轉(zhuǎn)矩；為受轉(zhuǎn)矩作用的長度， mm;G為材料的切變模量，MPa;d為軸徑，mm;為軸截面的極慣性距。，，故軸是安全的[8]。 2.4.3軸系零件的定位 (1)軸向定位 為了防止軸上零件發(fā)生沿軸向的移動，必須對其進行定位，來保證齒輪的正確嚙合，根據(jù)軸上零件的的安裝要求和對軸的結(jié)要求，要選擇不同的定位方式，常用的定位方式主要有軸肩定位、套筒定位、軸端擋圈和彈性擋圈，軸間定位方式在本設(shè)計中有用到，具體的結(jié)構(gòu)和參數(shù)見零件圖和明細表。 (2)周向定位 鍵主要是為了實現(xiàn)軸上零件的周向定位來傳遞轉(zhuǎn)距，鍵的形式用多種，因此要根據(jù)不同的要求來選擇不同型號的鍵，根據(jù)傳動的要求，本設(shè)計全部采用圓頭普通平鍵（A型），它的兩個側(cè)面是工作面，上表面與輪轂槽底之間留有間隙，其主要特點是定心性好、拆裝方便。 2.5 軸承的選擇 主軸通過粉碎室內(nèi)腔，其兩端由軸承固定在機架上。根據(jù)軸受力和軸徑的不同，，本設(shè)計選用的軸承是：深溝球軸承 已知此處軸徑，所以選內(nèi)徑為35mm的軸承，在機械設(shè)計手冊中選擇深溝球軸承；查表6-1，選擇型號為6007 GB/T276—94的軸承。另一處已知軸徑為，所以選內(nèi)徑也為25mm的軸承，選擇型號61805 GB/T276—94的軸承。所選的軸承基本參數(shù)如下： 軸承內(nèi)徑： d=35mm D=72mm B=17mm 基本額定動載荷：C=19.8KN 基本額定靜載荷：C=13.5KN 軸承內(nèi)徑： d=25mm D=52mm B=15mm 基本額定動載荷：C=10.8KN 基本額定靜載荷：C=6.95KN 滾動軸承的壽命計算： 2.6 鍵聯(lián)結(jié)的選擇與校核 2.6.1鍵的選擇 根據(jù)軸的直徑的不同，應(yīng)該選擇不同型號的鍵，另外，鍵的長度也有一系列的標準，應(yīng)該優(yōu)先選用第一系列，在以上的說明書中知道安裝鍵的軸有兩處，分別是第一段和第二段。第一段的直徑為25mm。 從機械設(shè)計手冊表中查得鍵的截面尺寸為：寬度，高度。 2.6.2校核鍵聯(lián)接的強度 M—傳遞的轉(zhuǎn)矩（N.M） d—軸的直徑（mm） l—鍵的工作長度（mm）;A型，l=L－b k—鍵與輪轂的接觸高度（mm）;k=h－t，h為鍵的高度， b—鍵的寬度（mm） t—切向鍵工作面寬度（mm） —鍵的許用切應(yīng)力（MPa） —鍵連接的許用擠壓應(yīng)力，/ MPa 可見聯(lián)接的擠壓強度滿足，即該鍵可以正常工作。 2.7軸承端蓋的設(shè)計 所選軸承外徑為62mm，在45-65的范圍內(nèi)，所以選擇螺釘直徑 d=6mm，螺釘數(shù)4個 b=5～10 b取5mm h=（0.8~1）b=8mm 3帶輪的選擇 帶輪是依靠帶與帶輪接觸面間的摩擦傳動的，它可以吸收和緩沖振動，結(jié)構(gòu)簡單，成本低廉。 3.1帶輪的結(jié)構(gòu)設(shè)計 小帶輪的材料選擇HT150，由小帶輪的基準直徑=40mm<2.5d=2.5×20=50mm，因此小帶輪可采用實心式；由機械設(shè)計第八版表8—10得Y型槽的結(jié)構(gòu)尺寸bd=5.3mm，ha=1.6mm，e=8mm，Z=2，da=dd+2ha=40+2×1.6=43.2mm， B=(Z—1)e×2f=(2—1)×8+2×6=20mm。 圖3-1小帶輪結(jié)構(gòu) 大帶輪的材料選擇HT150，由大帶輪的基準直徑=100mm<2.5d=2.5×24=60mm，因此大帶輪可采用腹板式，由機械設(shè)計第八版表8—10得Y型槽的結(jié)構(gòu)尺bd=5.3mm，ha=1.6mm，e=8mm，Z=2，da=dd+2ha=100+2×1.6=103.2mm，B=(Z—1)e×2f=(2—1)×8+2×6=20mm。 4電動機的選擇 進過多方查閱資料，確定偏心軸轉(zhuǎn)速為300r/min，所需功率為3KW，符合這一范圍的同步轉(zhuǎn)速為：查機械設(shè)計文獻３第155頁表12-1可知 ,, 根據(jù)容量和轉(zhuǎn)速，由設(shè)計手冊查出的電動機型號，因此有以下三種傳動比選擇方案，如下表4—1 表4—1電動機的類型 方方案 電動機型號 額定功率 同步轉(zhuǎn)速 滿載轉(zhuǎn)速 電動機質(zhì)量 參考價格 傳動裝置傳動比 1 Y-160M1-8 4 750 720 118 5.00 10.21 2 Y132M1-6 4 1000 960 73 3.48 13.61 3 Y112M-4 4 1500 1440 43 2.22 20.42 ①本參考價格為4極，同步轉(zhuǎn)速為750r\min，功率為4kw的電動機價格為1計算，表中數(shù)值為相對值，僅供參考。 綜合考慮電動機和傳動裝置的尺寸，質(zhì)量，價格以及傳動比，可見第三種方案比較合適，因此選定電動機的型號是Y-160M1-8。 5電機的尺寸及安裝 5.1電機的安裝 電機選定后，可根據(jù)其安裝尺寸設(shè)計機架及調(diào)節(jié)裝置，考慮到V帶傳動運轉(zhuǎn)一段時間以后，會因為帶的塑性變形和磨損而松弛。為了保證帶傳動正常工作，應(yīng)定期檢查帶的松弛程度，做相應(yīng)的調(diào)整。 設(shè)計采用定期張緊裝置，通過人為定期改變中心距的方法來調(diào)節(jié)帶的初拉力，使帶重新張緊。將電機安放在角鐵上，通過調(diào)節(jié)螺栓來改變中心距， 使V帶保持張緊狀態(tài)，將效率損失降到最低。電動機的安裝尺寸見表4-2該電動機的主要外型和安裝尺寸如下表5—1： 表5—1電動機主要外形尺寸 中心高 外形尺寸 地腳安裝尺寸 地腳螺栓孔直徑 軸伸尺寸 裝鍵部位尺寸 112 38×265×190 190×140 12 28×60 8 其主要外形安裝尺寸如圖5-1 圖5-1電動機主要外形安裝尺寸 5.2電機的調(diào)整 電機底座安放在的等邊角鋼的平面上，角鐵通過四根的全螺線螺栓固定在總機架上，定期檢查帶的松緊程度，如果需要調(diào)整中心距，可通過調(diào)節(jié)四根螺栓上鎖緊螺母的位置來實現(xiàn)。這樣有效的防止了帶的打滑，減小了機械效率損失。使電機功率得到合理應(yīng)用。 6 固定支撐部分的設(shè)計 6.1機架的設(shè)計 機架采用角鐵焊接而成，根據(jù)需要選擇熱軋槽鋼（GB/T707-1988）。 基本尺寸見表6-1 表 6-1 槽鋼尺寸 槽鋼 號數(shù) 尺寸/mm b h d t r r1 8 43 80 5.0 8.0 8.0 4.0 6.2軸承座的安放 由于軸承座為標準件，在選定軸承后，查手冊可知軸承座的安裝尺寸，見表6-2 表 6-2滾動軸承座安裝尺寸 型號 A1 L J S N1 N 質(zhì)量/（kg） SN205 46 165 130 M12 15 20 1.3 7.裝配質(zhì)量 （1）整機零部件完整，無缺件，安裝方便； （2）運動件操作靈活，無有卡死、磕碰現(xiàn)象； （3）非運動件無明顯偏移、翹曲等現(xiàn)象； （4）緊固件緊固可靠； （5）電動機、帶輪、鏈輪安裝牢固、可靠。 8.總結(jié) 通過此次設(shè)計使我掌握了科學研究的基本方法和思路，為今后的工作打下了基礎(chǔ)，在以后的日子我將會繼續(xù)保持這份做學問的態(tài)度和熱情。 我所選設(shè)計題目是“平板擠壓式核桃破殼機的設(shè)計”，之所以選擇這個題目，是因為我對這個課題比較的感興趣。在我的生活里，核桃破殼主要是在門縫里夾碎，這樣力道不容易把握，不是夾得太碎就是破裂程度很小，同時對門也造成了一定程度的破壞。因此，就想設(shè)計一款既省力又快速且破殼完整的機械。 經(jīng)過查找資料和老師的指導，以及上網(wǎng)搜集更多的相關(guān)學術(shù)論文、核心期刊、書籍等，終于對核桃破殼機有了一定得了解，心里有了大體的思路。最終確定的核桃破殼機有平板擠壓式破殼機。對于這一破殼機械有以下的結(jié)論： （1）通過對核桃物理機械特性的測定和內(nèi)力分析，提出了剝殼取仁原理破裂核桃殼，并研制了入料裝置 ，使得核桃成排狀向下落，有利于擠壓，有利于裂紋的產(chǎn)生與擴展，提高剝殼性能。 （2） 設(shè)備結(jié)構(gòu)參數(shù)：定板和破板一樣大其尺寸為長600mm，寬400mm。間距L和最小間隙s根據(jù)核桃尺寸等級在理論最佳值附近加以選擇。最佳運動參數(shù)：偏心軸轉(zhuǎn)速300 r／min，以每個核桃10g計，則最大生產(chǎn)率為18Okg/h。 致 謝 在這次畢業(yè)設(shè)計的過程中，我學到了很多，許多人也幫助了我。首先我要感謝我的指導老師蘭海鵬老師，是他不停的督促我，在設(shè)計過程中不斷的糾正我的錯誤，使我學會了許多東西，尤其是想問題和解決問題的思路，對我以后有很大的幫助。還有我的同學，隨時都會幫助我，這次最大收獲是掌握了Autocad制圖。謝謝他們幫助了我，使我順利的完成畢業(yè)設(shè)計。 13 參考文獻 [1]張玉先，張仲欣，謝秀英等.甘薯粉絲加工成套設(shè)備的設(shè)計[J].洛陽工學院學報，1998，19(2)：71～75. [2]張玲，楊戰(zhàn)勝，蘇澎.蔬菜紙形食品滾筒干燥成形及料漿調(diào)配[J].洛陽工學院學報，1999，20（2）：1～5. [3]陸振羲等.食品機械原理與設(shè)計[J].北京:中國輕工業(yè)出版社，1995.5：14～18. [4]李興國等.食品機械學[M]，上冊.成都:川教育出版社，1996. [5]楊軍，梁勤安.6BxH～800核桃青皮剝離.清洗機[J]農(nóng)機化，200l(5)28：7～9. [6]李忠新，楊軍，楊莉玲，等.核桃破殼取仁工藝及關(guān)鍵設(shè)備[J].農(nóng)機化研究，2008(12):28～29. [7]郭從善.核桃及其加工與利用[J].糧油食品科技，1999(5):24～26. [8]張木林，王瑋.1MS-800型塑料殘膜回收機的研究[J].農(nóng)牧與食品機械，1992(2):68～71. 塔里木大學 畢業(yè)論文（設(shè)計）開題報告 課題名稱對輥窩眼式式核桃破殼機的設(shè)計 學生姓名 學 號 所屬學院 機械電氣化工程學院 專 業(yè) 農(nóng)業(yè)機械化及其自動化 班 級 12-1 指導教師 起止時間 2011-12-1----2012-5-20 機械電氣化工程學院教務(wù)辦制 1、本課題的來源及研究的目的和意義 近年來，隨著經(jīng)濟發(fā)展和人民生活水平的提高，核桃的價值與功能進一步被世人認識和重視，國內(nèi)外市場對核桃及其加工品的需求量日益增長。旺盛的國內(nèi)外市場需求為我國核桃產(chǎn)業(yè)提供了廣闊的發(fā)展空間，也對我國核桃產(chǎn)品加工及質(zhì)量安全提出了更高的要求。但由于核桃品種繁雜，尺寸差異較大、形狀不規(guī)則、核仁間隙小，所以核桃的破殼取仁難度較大。破殼后還需要進行核仁分離，鑒于核仁密度相差不大，加之碎殼、碎仁上有許多毛刺，所以核仁分離也有相當難度。這是目前核桃破殼技術(shù)方面存在的主要問題。 解決以上難度的方法就是將破殼取仁分解為分級、導向、擠壓破殼（多點）、核仁分離四部分，逐一加以解決。 國外的核桃加工業(yè)已經(jīng)相當成熟，并且形成了一定的規(guī)模。在美國、澳大利亞等發(fā)達國家，核桃的采收、脫青皮、清洗、烘干以及破殼和殼仁分離等工序已完全實現(xiàn)J，機械化。我國核桃采后處理技術(shù)比較落后，在核桃脫青皮、破殼、殼仁分離等加工關(guān)鍵環(huán)節(jié)和設(shè)備成套性方面處于空白，嚴重制約了核桃油、核桃蛋白粉和核桃果汁等產(chǎn)品的精深加工。為提高我國核桃產(chǎn)業(yè)化加工技術(shù)水平，實現(xiàn)核桃生產(chǎn)的商品化，分析研究國外先進的核桃加工技術(shù)，摸索出了美國核桃加工工藝和生產(chǎn)線流程，結(jié)合我國核桃生產(chǎn)實際情況，設(shè)計出適合我國的核桃加工工藝和成套設(shè)備，是我們面臨的主要問題，也是研究核桃破殼的意義所在。 2、 本課題所涉及的問題在國內(nèi)（外）研究現(xiàn)狀及分析； 目前，核桃年產(chǎn)量在20萬t以上的國家僅有中國和美國。中美兩國的核桃產(chǎn)量占世界核桃總產(chǎn)量的50％左右，而最有代表性、生產(chǎn)水平最高和市場占有份額最大的當數(shù)美國。在美國、澳大利亞以及歐洲等發(fā)達國家，核桃絕大部分都經(jīng)過機械化生產(chǎn)線進行商品化處理。采收通過機械振蕩器將核桃果實振落到地面上，再由機械將果實收集起來，運到加工廠進行脫青皮、漂洗、烘干和帶殼包裝等處理。核桃仁加工也全部機械化，通過破殼機破殼，機械、氣流分選機進行殼仁分離，然后用分色機將果仁分為深色和淺色，再分為全仁和碎仁不同大小等級，最后分別包裝銷售。 我國的核桃產(chǎn)品加工起步較晚，相應(yīng)的加工規(guī)模小，技術(shù)水平低，遠遠落后于核桃生產(chǎn)發(fā)達國家。生產(chǎn)中采用人工敲打、去青皮、清洗和自然晾干干燥，核桃破殼取仁采用冷水浸泡、人工砸取的方式，大大降低了核桃和果仁加工質(zhì)量等級，且形不成規(guī)模生產(chǎn)。目前，我國有關(guān)科研和生產(chǎn)單位根據(jù)核桃生產(chǎn)的實際，研制出一些小型核桃采后商品化處理機械，如農(nóng)業(yè)科學院、河北興隆縣林業(yè)局研制的脫核桃青皮及清洗機，云南大理、楚雄研制的小型烘干機等，已在生產(chǎn)中初步應(yīng)用。這些加工都形不成規(guī)模效益，產(chǎn)品質(zhì)量也得不到保證，許多關(guān)鍵技術(shù)和設(shè)備還有待進一 現(xiàn)在核桃品種多，只能制造出適合大多數(shù)品種的適應(yīng)，對輥窩眼式式破殼法，研究很有意義，符合現(xiàn)階段的需要，適宜大產(chǎn)量的生產(chǎn)，進一步深加工。目前，雖然我國已研制開發(fā)出了一些堅果破殼機械，但是核桃破殼機的發(fā)展相當緩慢，并且能進行批量生產(chǎn)的成熟機型不多，遠不能滿足實際生產(chǎn)需要。具有代表性的核桃破殼機主要有：①農(nóng)業(yè)大學史建新、喬園園、董遠德等研究人員研制的新型核桃破殼機。該新型核桃破殼機結(jié)構(gòu)簡單、破殼效率高，能實現(xiàn)核桃的機械化破殼取仁[9] 3、 對課題所涉及的任務(wù)要求及實現(xiàn)預期目標的可行性分析； （1） 任務(wù)要求 對輥窩眼式核桃開口機主要由進料斗錐輥式分級裝置對輥窩眼式開裝置出料滑板機架和傳動系統(tǒng)等組成 ，如圖； 所示 錐輥式分級裝置為一對錐形輥 ，錐形輥大端與大端相對， 小端與小端相對 進料斗對準錐形輥， 的大端 這樣由兩錐形輥所形成的間隙由小逐漸變大， 對輥窩眼式開裝置為一對直徑相同的圓柱形擠壓輥 其上帶有窩眼 ，與錐輥式分級裝置小間隙端所對應(yīng)，的窩眼深度小，與大間隙端所對應(yīng)的窩眼深度大 ，兩輥上的窩眼配合對核桃 ，實施擠壓開錐輥式分級裝置上 ，的核桃進行分級時，不應(yīng)受擠壓 所以一對錐形輥應(yīng)相開轉(zhuǎn)動，對輥窩眼式開 裝置要對落在其窩眼內(nèi)的核桃實施擠壓開所以一對圓柱形擠壓輥應(yīng)相對轉(zhuǎn)動 （2） 可行性分析 對輥窩眼式核桃破殼機已經(jīng)是比較成熟的裝置，但是在設(shè)計過程中我們得把握住幾個大的方面。1、我們要弄清楚它的主要結(jié)構(gòu)；2、掌握它的工作原理。 4、 本課題需要重點研究的、關(guān)鍵的問題及解決的思路； <1>重點研究的、關(guān)鍵的問題 （1） 對輥直徑的確定 （2） 對輥長度的確定 （3） 兩錐形輥間隙與錐度的確定 （4） 核桃在錐輥式分級裝置上的運動分析 <2>解決的思路 （1） 研究核桃的外形形狀，設(shè)計初步方案，在對其做可行性分析。 （2） 準確的確定出對輥的直徑、長度、以及間隙和錐度的距離。 5、完成本課題所必須的工作條件及解決的辦法； 本課題難度較大較復雜，所以在設(shè)計的過程中必須得仔細認真。精確的測量以及嚴謹?shù)挠嬎闶鞘滓獥l件。其次課題主要研究四部分（1）對輥窩眼式開口裝置結(jié)構(gòu)參數(shù)設(shè)計（2)錐輥式分級裝置結(jié)構(gòu)參數(shù)設(shè)計（3）核桃在錐輥式分級裝置上的運動分析（4）傳動系統(tǒng)的分析；我們可以通過查閱大量的參考文獻資料來分析，以及仿真軟件來分析設(shè)計。 6、完成本課題的工作方案及進度計劃； 第1周—第2周 通過查找文獻資料，了解核桃破殼的國內(nèi)外現(xiàn)狀。 做任務(wù)書。 第2周—第5周 設(shè)計對輥窩眼式核桃破殼機的總體方案。寫好開題報告。 第6周—第9周 對對輥窩眼式核桃的結(jié)構(gòu)進行具體設(shè)計。畫零件圖和裝配圖。 第10周—第12周 撰寫設(shè)計說明書，對部分問題修改、調(diào)整。做好答辯PPT. 7、主要參考文獻 （1）張玉先， 張仲欣，謝秀英等。 甘薯粉絲加工成套設(shè)備的設(shè)計 。洛陽工學院學報，1998，19（2）：71-75 （2）張玲，、楊戰(zhàn)勝，蘇 澎。蔬菜紙形食品滾筒干燥成形及料漿調(diào)配。洛陽工學院學報，1999，20（2）：1-5 （3）陸振羲等。食品機械原理與設(shè)計。北京：中國輕工業(yè)出版社，1995 （4）李興國等。，食品機械學。上冊，成都：川教育出版社,1996 （5）楊軍，梁勤安．6BxH一800核桃青皮剝離、清洗機[J]農(nóng)機化，200l(5)：28． (6)李忠新，楊軍，楊莉玲，等．核桃破殼取仁工藝及關(guān)鍵設(shè)備[j]．農(nóng)機化研究。2008(12)：28—29． (7)郭從善．核桃及其加工與利用[J]．糧油食品科技，1999(5)：24—26． 學生簽名 譚向明 2011年 12月 26 日 指導教師審閱意見 指導教師簽名 年 月 日 第 18 頁 翻譯 英文原文 COMMINUTION IN A NON-CYLINDRICAL ROLL CRUSHER* P. VELLETRI ~ and D.M. WEEDON ~ ~[ Dept. of Mechanical & Materials Engineering, University of Western Australia, 35 Stirling Hwv, Crawley 6009, Australia. E-mail piero@mech.uwa.edu.au § Faculty of Engineering and Physical Systems, Central Queensland University, PO Box 1!:;19, Gladstone, Qld. 4680, Australia (Received 3 May 2001; accepted 4 September 2001) ABSTRACT Low reduction ratios and high wear rates are the two characteristics ntost commonh" associated with conventional roll crushers. Because of this, roll crushers are not often considered Jor use in mineral processing circuits, attd many of their advantages are being largely overlooked. This paper describes a novel roll crusher that has been developed ipt order to address these issues.Relbrred to as the NCRC (Non-Cylindrical Roll Crusher), the new crusher incorporates two rolls comprised qf an alternating arrangement of platte attd convex or concave su@wes. These unique roll prqfiles improve the angle qf nip, enabling the NCRC to achieve higher reduction ratios than conventional roll crushers. Tests with a model prototype have indicated thar evell fi)r very hard ores, reduction ratios exceeding lO:l can be attained. In addition, since the comminution process in the NCRC combines the actions of roll arM jaw crushers there is a possibili O' that the new profiles may lead to reduced roll wear rates. ? 2001 Elsevier Science Ltd. All rights reserved. Keywords: Comminution; crushing INTRODUCTION Conventional roll crushers suffer from several disadvantages that have lcd to their lack of popularity in mineral processing applications. In particular, their low reduction ratios (typically limited to about 3:1) and high wear rates make them unattractive when compared to other types of comminution equipment, such as cone crushers. There are, however, some characteristics of roll crushers that are very desirable from a mineral processing point of view. The relatively constant operating gap in a roll crusher gives good control over product size. The use of spring-loaded rolls make these machines tolerant to uncrushable material (such as tramp metal). In addition, roll crushers work by drawing material into the compression region between the rolls and do not rely on gravitational feeci ~like cone and jaw crushers. This generates a continuous crushing cycle, which yields high throughput rates and also makes the crusher capable of processing wet and sticky ore. The NCRC is a novel roll crusher that has been dcveloped at the University of Western Australia in ordcr to address some of the problems associated with conventional roll crushers. The new crusher incorporates two rolls comprised of an alternating arrangement of plane and convex or concave surfaccs. Thcse unique roll profiles improve the angle of nip, enabling the NCRC to achieve higher reduction ratios than conventional roll crushers. Preliminary tests with a model prototype have indicated that, even for very hard oics, reduction ratios exceeding 10:I can be attained (Vellelri and Weedon, 2000). These initial findings were obtained for single particle feed. where there is no significant interaction between particles during comminution. The current work extends the existing results bv examining inulti-particle comminution inthe NCRC. It also looks at various othcr factors that influencc the perli~rmance of the NCRC and explores the effectiveness of using the NCRC for the processing of mill scats. PRINCIPLE OF OPERATION The angle of nip is one of the main lectors effccting the performance of a roll crusher. Smaller nip angles are beneficial since they increase tl~e likelihood of parlictes bcing grabbed and crushed by lhe rolls. For a given feed size and roll gap, the nip angle in a conventional rtHl crusher is limited by the size of thc rolls. The NCRC attempts to overcome this limitation through the use of profiled rolls, which improve the angle of nip at various points during one cycle (or revolution) of the rolls. In addition to the nip angle, a number of other factors including variation m roll gap and mode of commmution were considered when selecting Ille roll profiles. The final shapes of the NCRC rolls are shown in Figure I. One of the rolls consists {sI an alternating arrangement of plane and convex surfaces, while the other is formed from an alternating arrangement of phme and concave surlaccs. The shape of the rolls on the NCRC result in several unique characteristics. Tile most important is that, lk)r a given particle size and roll gap, the nip angle generated m the NCRC will not remain constant as the rolls rotate. There will be times when the nip angle is much lower than it would be for the same sized cylindrical rolls and times when it will be much highcr. The actual variation in nip angle over a 60 degree roll rotation is illustrated in Figure 2, which also shows the nip angle generated under similar conditions m a cylindrical roll crusher of comparable size. These nip angles were calculated for a 25ram diameter circular particle between roll of approximately 200ram diameter set at a I mm minimum gap. This example can be used to illustrate the potential advantage of using non-cylindrical rolls. In order for a particle to be gripped, thc angle of nip should normally not exceed 25 ° . Thus, the cylindrical roll crusher would never nip this particle, since the actual nip angle remains constant at approximately 52 °. The nip angle generated by the NCRC, however, tidls below 25 ° once as the rolls rotate by (~0 degrees. This means that the non-cylindrical rolls have a possibility of nipping the particlc 6 times during one roll rewHution. EXPERIMENTAL PROCEDURE The laboratory scale prototype of the NCRC (Figure 3) consists of two roll units, each comprising a motor, gearbox and profiled roll. Both units are mounted on linear bearings, which effectively support any vertical componcnt of force while enabling horizontal motion. One roll unit is horizontally fixed while the other is restrained via a compression spring, which allows it to resist a varying degree of horizontal load. The pre-load on the movable roll can be adjusted up to a maximum of 20kN. The two motors that drive the rolls are electronically synchronised through a variable speed controller, enabling the roll speed to be continuously varied up to 14 rpm (approximately 0.14 m/s surface speed). The rolls have a centre-to-centre distance ~,at zero gap setting) of I88mm and a width of 100mm. Both drive shafts are instrumented with strain gauges to enable the roll torque to be measured. Additional sensors are provided to measure the horizontal force on the stationary roll and the gap between the rolls. Clear glass is fitted to the sides of the NCRC to facilitate viewing of the crushing zonc during operation and also allows the crushing sequence to bc recorded using a high-speed digital camera. Tests were performed on several types of rocks including granite, diorite, mineral ore, mill scats and concrete. The granite and diorite were obtained from separate commercial quarries; the former had been pre-crushed and sized, while the latter was as-blasted rock. The first of the ore samples was SAG mill feed obtained from Normandy Mining's Golden Grove operations, while the mill scats were obtained from Aurora Gold's Mt Muro mine site in central Kalimantan. The mill scats included metal particles of up to 18ram diameter from worn and broken grinding media. The concrete consisted of cylindrical samples (25mm diameter by 25ram high) that were prepared in the laboratory in accordance with the relevant Australian Standards. Unconfined uniaxial compression tests were performed on core samples (25mm diameter by 25mm high) taken from a number of the ores. The results indicated strength ranging from 60 MPa for the prepared concrete up to 260 MPa for the Golden Grove ore samples. All of the samples were initially passed through a 37.5mm sieve to remove any oversized particles. The undersized ore was then sampled and sieved to determine the feed size distribution. For each trial approximately 2500g of sample was crushed in the NCRC. This sample size was chosen on the basis of statistical tests, which indicated that at least 2000g of sample needed to be crushed in order to estimate the product P80 to within +0.1ram with 95% confidence. The product was collected and riffled into ten subsamples, and a standard wet/dry sieving method was then used to determine the product size distribution. For each trial, two of the sub-samples were initially sieved. Additional sub-samples were sieved if there were any significant differences in the resulting product size distributions. A number of comminution tests were conducted using the NCRC to determine the effects of various parameters including roll gap, roll force, feed size, and the effect of single and multi-particle feed. The roll speed was set at maximum and was not varied between trials as previous experiments had concluded that there was little effect of roll speed on product size distribution. It should be noted that the roll gap settings quoted refer to the minimum roll gap. Due to the non-cylindrical shape of the rolls, the actual roll gap will vary up to 1.7 mm above the minimum setting (ie: a roll gap selling of l mm actually means 1-2.7mm roll gap). RESULTS Feed material The performance of all comminution equipment is dependent on the type of material being crushed. In this respect, the NCRC is no different. Softer materials crushed in the NCRC yield a lower P80 than harder materials. Figure 4 shows the product size distribution obtained when several different materials were crushed under similar conditions in the NCRC. It is interesting to note that apart from the prepared concrete samples, the P80 values obtained from the various materials were fairly consistent. These results reflect the degree of control over product size distribution that can be obtained with the NCRC. Multiple feed particles Previous trials with the NCRC were conducted using only single feed particles where there was little or no interaction between particles. Although very effective, the low throughput rates associated with this mode of comminution makes it unsuitable for practical applications. Therefore it was necessary to determine the effect that a continuous feed would have to the resulting product size distribution. In these tests, the NCRC was continuously supplied with feed to maintain a bed of material level with the top of the rolls. Figure 5 shows the effect that continuous feed to the NCRC had on the product size distribution for the Normandy Ore. These results seem to show a slight increase in P80 with continuous (multi-particle) feed, however the shift is so small as to make it statistically insignificant. Similarly, the product size distributions would seem to indicate a larger proportion of fines for the continuously fed trial, but the actual difference is negligible. Similar trials were also conducted with the granite samples using two different roll gaps, as shown in Figure 6. Once again there was little variation between the single and multi-particle tests. Not surprisingly, the difference was even less significant at the larger roll gap, where the degree of comminution (and hence interaction between particles) is smaller. All of these tests would seem to indicate that continuous feeding has minimal effect on the performance of the NCRC. However, it is important to realise that the feed particles used in these trials were spread over a very small size range, as evident by the feed size distribution shown in Figure 6 (the feed particles in the Normandy trials were even more uniform). The unilormity in feed particle size results in a large amount of free space, which allow:s for swelling of the broken ore in the crushing chamber, thereby limiting the amount of interaction between particles. True "choke" feeding of the NCRC with ore having a wide distribution of particle sizes (especially in the smaller size range) is likely to generate much larger pressures in the crushing zone. Since the NCRC is not designed to act as a "'high pressure grinding roll" a larger number of oversize particles would pass between the rolls under these circumstances. Roll gap As with a traditional roll crusher, the roll gap setting on the NCRC has a direct influence on the product size distribution and throughput of the crusher. Figure 7 shows the resulting product size distribution obtained when the Aurora Gold ore (mill scats) was crushed at three different roll gaps. Plotting the PSO values taken from this graph against the roll gap yields the linear relationship shown in Figure 8. As explained previously, the actual roll gap on the NCRC will vary over one revolution. This variation accounts for the difference between the specified gap setting and product Ps0 obtained from the crushing trials. Figure 8 also shows the effect of roll gap on throughput of the crusher and gives an indication of the crushing rates that can be obtained with the laboratory scale model NCRC. Roll force The NCRC is designed to operate with minimal interaction between particles, such that comminution is primarily achieved by fracture of particles directly between the rolls. As a consequence, the roll force only needs to bc large enough to overcome the combined compressive strengths of the particles between the roll surlaces. If the roll force is not large enough then the ore particles will separate the rolls allowing oversized particles to lall through. Increasing the roll force reduces the tendency of the rolls to separate and therefore provides better control over product size. However, once a limiting roll force has been reached (which is dependent on the size and type of material being crushed) any further increase in roll force adds nothing to the performance of the roll crusher. This is demonstrated in Figure 9, which shows that for granite feed of 25-3 Imm size, a roll force of approximately 16 to 18 kN is required to control the product size. Using a larger roll force has little effect on the product size, although there is a rapid increase in product P80 if the roll force is reduced bek>w this level. As mentioned previously, the feed size distribution has a significant effect on the pressure generated in the crushing chamber. Ore that has a finer feed size distribution tends to "choke" the NCRC more, reducing the effectiveness of the crusher. However, as long as the pressure generated in not excessive the NCRC maintains a relatively constant operating gap irrespective of the feed size. The product size distribution will, therefore, also bc independent of the feed size distribution. This is illustrated in Figure 10, which shows the results of two crushing trials using identical equipment settings but with feed ore having different size distributions. In this example, the NCRC reduced the courser ore from an Fs0 of 34mm to a Ps0 of 3.0mm (reduction ratio of 11:1), while the finer ore was reduced from an Fs0 of 18mm to a Pso of 3.4mm (reduction ratio of 5:1). These results suggest that the advantages of using profiled rolls diminish as the ratio of the feed size to roll size is reduced. In other words, to achieve higher reduction ratios the feed particles must be large enough to take advantage of the improved nip angles generated in the NCRC. Mill scats Some grinding circuits employ a recycle or pebble crusher (such as a cone crusher) to process material which builds up in a mill and which the mill finds hard to break (mill scats). The mill scats often contain worn or broken grinding media, which can find its way into the recycle crusher. A tolerance to uncrushable material is therefore a desirable characteristic for a pebble crusher to have. The NCRC seems ideally suited to such an application, since one of the rolls has the ability to yield allowing the uncrushable material to pass through. The product size distributions shown in Figure 1 1 were obtained from the processing of mill scats in the NCRC. Identical equipment settings and feed size distributions were used for both results, however one of the trials was conducted using feed ore in which the grinding media had been removed. As expected, the NCRC was able to process the feed ore containing grinding media without incident. However, since one roll was often moving in order to allow the grinding media to pass, a number of oversized particles were able to fall through the gap without being broken. Consequently, the product size distribution for this feed ore shows a shift towards the larger particle sizes, and the Ps0 value increases from 4ram to 4.7mm. In spite of this, the NCRC was still able to achieve a reduction ratio of almost 4:1. Wear Although no specific tesls were conducted to determine the wear rates on the rolls of the NCRC, a number of the crushing trials were recorded using a high-speed video camera in order to try and understand the comminution mechanism. By observing particles being broken between the rolls it is possible to identify portions of the rolls which are likely to suffer from high wear and to make some subjective conclusions as to the effect that this wear will have on the perlbrmance of the NCRC. Not surprisingly, the region that shows up as being the prime candidate for high wcar is the transition between the flat and concave surfaces. What is surprising is that this edge does not play a significant role in generating the improved nip angles. The performance of the NCRC should not be adversely effccted by wear to this edge because it is actually the transition between the fiat and convex surfaces (on the opposing roll) that results in the reduced nip angles. The vide() also shows that tor part of each cycle particles are comminuted between the flat surfaces of the rolls, in much the same way as they would be in a jaw crusher. This can be clearly seen on the sequence of images in Figure 12. The wear on the rolls during this part of the cycle is likely' to be minimal since there is little or no relative motion between the particles and the surface of the rolls. CONCLUSIONS The results presented have demonstrated some of the factors effecting the comminution of particles in a non-cylindrical roll crusher. The high reduction ratios obtained from early single particle tests can still be achieved with continuous multi-particle feed. However, as with a traditional roll crusher, the NCRC is susceptible to choke feeding and must be starvation fed in order to operate effectively. The type of feed material has little effect on the performance of the NCRC and, although not tested, it is anticipated that the moisture content of the feed ore will also not adversely affect the crusher's per[Brmance. Results from the mill scat trials are particularly promising because they demonstrate that the NCRC is able to process ore containing metal from worn grinding media. The above factors, in combination with the flaky nature of the product generated, indicate that the NCRC would make an excellent recycle or pebble crusher. It would also be interesting to determine whether there is any difference in the ball mill energy required to grind product obtained from the NCRC compared that obtained from a cone crusher. 中文譯文 摘要 低的破碎比和高的磨損率是與傳統(tǒng)的破碎機相聯(lián)系的很常見的兩個特性。因為這點，在礦石處理流程的應(yīng)用中，很少考慮到它們，并且忽略了很多它們的優(yōu)點。本文描述了一個已被發(fā)展起來的新穎的對輥破碎機，旨在提出這些論點。作為NCRC,這種新式破碎機結(jié)合了兩個輥筒，它們由一個交替布置的平面和一個凸的或者凹的表面組成。這種獨特的輥筒外形提高了嚙合角，使NCRC可以達到比傳統(tǒng)輥式破碎機更高的破碎比。用一個模型樣機做的試驗表明：即使對于非常硬的礦石，破碎比任可以超過10。另外，既然在NCRC的破碎處理中結(jié)合了輥式和顎式破碎機的作用，那就有一種可能：那種新的輪廓會帶來輥子磨損率的降低。 關(guān)鍵字： 介紹 傳統(tǒng)的輥筒破碎機因為具有幾個缺陷而導致了其在礦石處理應(yīng)用中的不受歡迎。尤其是當與其它的一些破碎機比起來，諸如圓錐破碎機等，它們的低破碎比（一般局限在3以內(nèi)）和高的磨損率使它們沒