裝配圖單線畫線機

裝配圖單線畫線機,裝配,單線,畫線 畫線機是用滾輪等再日用陶瓷、玻璃制品的圓形或橢圓形器皿上，畫一條或多條彩色、彩帶的機械。可以分為單色機畫線機和多色畫線機。本次設計主要是研究設計單色畫線機，即單線畫線機。陶瓷是無機材料之母，從家庭至宇宙對陶瓷的渴求量愈來愈大，其許多優(yōu)越、潛在特性不斷被發(fā)現(xiàn)，近20年來各國非常重視陶瓷的研究、開發(fā)與應用，各國將先后進入陶瓷世界。陶瓷一般指陶器和瓷器的合稱，“陶”為燒成之意，“瓷”是指硬而之謎的器物。陶瓷是我國歷史悠久的古老文化之一，也是文明的象征。我國陶瓷的出現(xiàn)可上溯到距今一萬年左右，距今3000年前的殷周時代，有了以高嶺土為原料的白陶，已懂得用釉的方法。原始瓷器是以鐵為著色劑的青釉器，是青瓷的前身。晉朝出現(xiàn)“瓷”字，說明當時人們已認識到陶和瓷的區(qū)別。陶瓷是一種與我們日常生活以及在各種工程項目能夠經(jīng)常接觸到的材料。隨著技術經(jīng)濟的發(fā)展，在某些科學領域陶瓷已形成其他材料無法比擬的優(yōu)點。例如，工程陶瓷，由工程陶瓷的制成的零件具有耐磨、耐熱、耐摩擦、熱膨脹系數(shù)小等一系列優(yōu)點，是當今世界高技術含量的產(chǎn)品。在國外已越來越多地應用工程陶瓷取代金屬零件，使產(chǎn)品地壽命、穩(wěn)定性等大大提高。在如，低溫燒結陶瓷（LTCC）大家一定還都記得在手機行業(yè)剛剛起步時的代表作大哥大，它又笨又重，攜帶不方便，而現(xiàn)在的手機就越來越袖珍了，這里的關鍵就是LTCC技術的發(fā)展。;LTCC技術是把很多東西整合在一起，其全稱為“低溫共燒陶瓷”技術，簡單地說，就是一種整合、小型化地技術將各種被動組件整合在一起，縮小到陶瓷式電路板上，如果沒有它，手機是無法達到輕薄短小地效果地。總之，陶瓷已經(jīng)成為與我們密不可分地伙伴了。我國陶瓷生產(chǎn)歷史悠久，日用陶瓷一直暢銷國內外。在我們的生活中，能夠給人們留下直觀印象的是日用陶瓷。這里不乏一些工藝美術品。因此，對于陶瓷制品，我們不僅要求其本身質量要好、使用方便，同時還要對其表面進行一定程度的美化處理，繪制出各種線條精美的圖案，增加美感及藝術感。然而，傳統(tǒng)的陶瓷畫線主要是由手工完成的，畫出的線條寬窄不一，嚴重影響產(chǎn)品的質量，與其是在畫寬度3mm以上的線條時，用手工的方法根本無法實現(xiàn)，因此生產(chǎn)陶瓷的廠家不得不將線條印成畫紙，將畫紙貼在陶瓷制品上進行彩烤，而這又大大提高了成本。陶瓷生產(chǎn)廠家一直都無法解決這一問題。隨著機械化、自動化技術的不斷發(fā)展，研制新型高效的畫線機以代替手工作業(yè)已成為迫切需要。目前，世界各國對裝飾機械的研制十分迅速，不斷推陳出新。其中以畫線機和印花機發(fā)展最為迅速。我國在這方面發(fā)展比較晚，目前用于生產(chǎn)陶瓷機械數(shù)量較小，品種較單一，因此有必要投入人力物力財力設計新產(chǎn)品，引進設備，消化技術。1.3 工作內容和要求1.3.1 畫線機總體參數(shù)的確定主要技術指標及重要技術參數(shù)主要技術指標 畫線色種: 單色公稱生產(chǎn)能力：6-12件/分 彩色寬度： 0.25-6mm 制品最大直徑：406mm 制品最大高度：230mm 總功率消耗： 3.5kw 整機重要： 約100kg 外型尺寸： 約1.4m0.8m1.6m重要技術參數(shù) 電動機的變速范圍：1000-3000rpm 最短畫線時間： 1.22s 最長畫線時間： 4.14s 畫線輔助時間： t3s1.3.2 單線畫線機的機構設計單線自動畫線機主要由主機架、工作臺、施彩器組件、真空泵、氣動系統(tǒng)、電器部分組成.其主要功能包括：驅動功能、畫線功能、自動裝卸功能、輔助功能、測控功能、安全保護功能。功能分解如下圖：單線畫線機驅動施彩頭電機驅動吸盤主電機驅動單線畫線機前伸后仰吸 盤吸氣放氣輔 助支撐導向測控單線畫線機畫線安全保護漏電保護過載保護 圖1 單線畫線機的功能結構圖依據(jù)這些功能，系統(tǒng)組成為：動力系統(tǒng)、傳動系統(tǒng)、執(zhí)行系統(tǒng)、輔助系統(tǒng)、測控系統(tǒng)、安全保護系統(tǒng)。各主要系統(tǒng)概述如下：動力系統(tǒng)：為操作部件提供動力，如機械手的仰俯、旋轉、單線機的移動畫線。本設計中動力裝置為電動機和氣壓系統(tǒng)。傳動系統(tǒng)：是將動力機的運動和動力傳遞給執(zhí)行機構或執(zhí)行構件的中間裝置。主要有帶傳動、齒輪傳動、蝸輪蝸桿傳動等。在本設計中，由電動機到施釉輪之間的傳動是通過帶傳動來完成的。執(zhí)行機構：能直接完成預期工作任務的機構和部件，為完成對陶瓷制品的畫線功能所需的執(zhí)行機構的部件主要是機械手、施釉輪及帶釉輪。測控系統(tǒng)：是控制畫線機各執(zhí)行機構按規(guī)定程序和要求，以一定順序和規(guī)律運動完成畫線機，具體測控有機械手旋轉角度、升降角度、單線機的位移量、放氣時間等。輔助系統(tǒng)：為完成畫線功能，以上各功能還需要一些輔助系統(tǒng)支持，如支承、下料、送料等輔助系統(tǒng)。為了保證準確可靠地實現(xiàn)畫線機地畫線功能，實現(xiàn)畫線自動化，需滿足以下條件： 機構地布局應合理，相互之間保證不干涉，不阻擋。 總體布局應使工人操作安全方便，節(jié)省空間。 吸盤吸、放氣時要考慮工人操作時間地合理性。 機器的電動、氣動部分都需外殼罩住，已加工與未加工的工件放置要整齊，物料陪送線路要清晰、合理。 本機分四部分安裝，各部分安裝好后再連接在一起構成一個整體，這樣能夠提高效率，保證質量且運輸時也方便。1.3.3 相關部件、零件設計 單線畫線機主要有施彩器傳動系統(tǒng)、氣動系統(tǒng)、真空系統(tǒng)、電器系統(tǒng)四部分.其中零件要首先選擇標準件,若標準件中沒有合適的零件可自行進行設計.在本機的設計中,我們需要設計選擇電機、傳動系統(tǒng)、減速器、阻尼裝置等. 表1 形態(tài)學矩陣分功能 解 法 1 2 3 4 5 6A動力源B位移傳動C位移D取物傳動E取物電動機齒輪傳動軌道及車輪拉桿挖斗汽油機蝸輪蝸桿傳動輪胎繩傳動抓斗柴油機帶傳動履帶汽缸傳動鉗式斗蒸氣透平鏈傳動氣墊液壓缸傳動機械手液動機液力耦合器氣動馬達1.3.3.1 電動機的選擇 電動機施機械系統(tǒng)中最常用的動力機,與其他動力機相比,它具有較高的驅動效率,且其種類和型號較多,與工作機械連接方便,具有良好的調速、啟動、制動和反向控制性能.易于實現(xiàn)遠距離、自動控制,工作時無環(huán)境污染,可滿足大多數(shù)機械的工作要求.1.3.3.2 氣動系統(tǒng)的選擇特點: 元件結構簡單、緊湊、易于制造,且不污染環(huán)境.可集中供氣和遠距離輸送,便于管理. 易于實現(xiàn)快速的直線往復運動,擺動的高速轉動.輸出力和運動速度調節(jié)很方便,且能實現(xiàn)過載自動保護. 工作環(huán)境適應性較強. 由于壓縮空氣的工作壓力不高,一般在0.4-0.6MPa,故輸出力和力矩不高,且傳動效率也較低,一般用于輸出力不大的傳動裝置.采用擴力機械或氣液增壓裝置,可提高輸出力. 由于空氣有壓縮性,故運動速度的穩(wěn)定性較差,較難實現(xiàn)精密控制.采用氣液聯(lián)動方式,可提高運動速度的穩(wěn)定性. 由于氣信號的傳遞速度比電信號慢得多,故不宜用于遙控及復雜得控制系統(tǒng).組成:起源部分、執(zhí)行部分、控制部分、輔助部分.1.3.3.3減速器的選擇本機可選擇常用的阿基米德圓柱蝸桿減速器,這種減速器適用于蝸桿轉速不超過1500r/min,環(huán)境溫度為-40-+40C的場合,可以正反兩向運轉.在選用減速器時,首先根據(jù)工作要求確定傳動比i,再按蝸輪軸的計算轉矩查蝸輪軸額定轉矩表,確定減速器的中心距.然后按機器布置,潤滑等要求選擇減速器的裝配形式.必要時要進行散熱計算.1.4 課題的重點和難點1.4.1 單線畫線機設計重點單線自動畫線機的用途是在陶瓷制品上畫出裝飾線條或圖案，以達到美化陶瓷質樸那的目的。這種機械代替了手工畫線工作，提高了勞動生產(chǎn)率以及精度，可以畫出粗細均勻的線條，克服了手工作業(yè)的缺點與不足，滿足了廣大消費者的審美要求并提高了勞動生產(chǎn)率。我國地域遼闊，該機不受地形氣候等外界因素影響和限制，并且易于維修，工作可靠，適用于相關陶瓷生產(chǎn)部門。經(jīng)各種常用系統(tǒng)的計算比較得出，當施釉輪與被加工陶瓷盤間實現(xiàn)純滾動，且滾動畫線速度在0.4m/s時,畫線效果最佳，故單線畫線機的一切設計要以此為宗旨。通過帶傳動的裝置，電動機將動力傳遞給了施釉輪與帶釉輪，兩輪開始旋轉，此時主從摩擦輪接觸，帶動陶瓷旋轉，設計合理的技術參數(shù)，可實現(xiàn)上述的畫線速度要求，畫線機開始畫線。在每個陶瓷畫線的開始與結束，為了便與裝卸陶瓷，支承施釉頭組件的桿件必須能夠實現(xiàn)擺動，以使施釉頭組件準確靠近、離開瓷器。經(jīng)多方面的比較，我們最終選擇氣動系統(tǒng)實現(xiàn)這一環(huán)節(jié)。另外，在被加工定位的這一環(huán)節(jié)也有講究。由于陶瓷制品易碎這一特點，使得我們必須摒棄普通機床夾具而選擇其它的定位夾緊方法?；诒P狀陶瓷表面光潔的特點，我們想到了可以利用真空吸附夾緊方式定位，及手部為真空吸盤。1.4.2單線畫線機的設計難點對于單線自動畫線機，最重要的是能夠畫出均勻清晰的線條，以滿足廣大消費者的審美要求，因此對各機構的運動精度和定位精度要求較高。畫線機的運動精度和定位精度主要包括以下幾個方面：施彩頭組件擺動的運動與機械手的運動需協(xié)調一致，即與裝、卸料工作要配合。為了保證施釉輪與制品之間的接觸精度，單線機的前進與后退要有較高的定位精度。機械手的旋轉角度是否精確，關系到安放工件時的中心線能否與吸盤中心重合。由于這些精度將直接關系到產(chǎn)品質量，建議采取開環(huán)伺服系統(tǒng)進行控制。1.5 單線畫線機的機械系統(tǒng)的方案設計機械系統(tǒng)的方案設計，是機械設計中極其重要的一環(huán)。正確、合理的機械系統(tǒng)的方案，對于提高機械的性能、質量、市場競爭力和經(jīng)濟效益等都是至關重要的。單線畫線機制成品M 陶瓷器件M指令S信息顯示S能量E輸出E 圖2 單線畫線機黑箱圖1.5.1 執(zhí)行系統(tǒng)的方案設計 包括執(zhí)行系統(tǒng)的功能原理設計，執(zhí)行系統(tǒng)的運動規(guī)律設計，執(zhí)行系統(tǒng)的形式設計，執(zhí)行系統(tǒng)的協(xié)調設計以及執(zhí)行系統(tǒng)的方案評價。1.5.2 傳動系統(tǒng)的方案設計 包括選擇合理的傳動裝置的類型、確定傳動路線的方案以及合理分配傳動系統(tǒng)。1.5.3 原動機類型的選擇 包括原動機的類型、轉速、以及原動機容量的選擇。1.5.4 操縱控制系統(tǒng)的選擇 包括機電控制系統(tǒng)、機液控制系統(tǒng)、電業(yè)控制系統(tǒng)、液壓控制系統(tǒng)、氣動系統(tǒng)、電氣控制系統(tǒng)以及微機控制系統(tǒng)。1.6 國內外同類產(chǎn)品的對比國外很多國家重視裝飾機械的研制與開發(fā)，特別時在畫線機、印花機方面的發(fā)展時十分迅速的，與國外產(chǎn)品比起來，該產(chǎn)品的生產(chǎn)效率低且柔性化程度不高；但在國內，由于這一方面起步較晚，發(fā)展較慢，所以該產(chǎn)品已經(jīng)達到了一個新的水平。1.7關于用戶的需求和企業(yè)發(fā)展計劃的介紹對于用戶來說，他們希望用更好的陶瓷制品，外表美觀大方，且物美價廉，這就是用戶所追求的方向。因此，企業(yè)的發(fā)展應以此為導向，來滿足用戶的需求。這樣的企業(yè)才能有所創(chuàng)造，有所發(fā)展。1.8 可能用到的知識和技能 理論知識：機械原理、機械設計、材料力學、機械制造技術等 應用軟件：AutoCAD、CATIA、ADAMS、Office word等。1.9 需要自學的知識和技能 由于在本科的學習階段，我們主要學習了一些專業(yè)理論知識而過少解除各科知識在實際當中的應用。因此，在設計過程中，我們應注重在實際應用方面豐富自己的頭腦。針對這次的畢業(yè)設計，我應多多學習關于陶瓷加工機械方面的知識，爭取創(chuàng)造條件實際觀察陶瓷的單線畫線機的工作過程，了解其原理。另外，在三維造型方面，目前市面流行的工程軟件很多，除了CATIA，我們還可以考慮用其他的軟件。若有條件，我會考慮學習另外的軟件來進行三維造型。2 工作計劃表2 進度計劃表2006.2-2006.3調研、譯文、參考文獻2006.4.1-2006.4.15總體布置、草圖、開題報告2006.4.15-2006.5.1總體設計、總裝圖2006.5.1-2006.5.15部件設計、相關計算2006.5.15-2006.6.1零件、部件、設計、論文2006.6.1-2006.6.20修改、完善、圖紙論文、答辯摘要本次設計的是單色自動畫線機，其主要功能是在一個瓷器上畫出一條粗細均勻的線。本文主要討論了設計的必要性，通過系統(tǒng)功能分解、功能合成、方案設計提出新方案。這一點對產(chǎn)品的成敗起決定性作用。計算和安排一些與設計有關的重要數(shù)據(jù)的設計計算書、分析典型零部件的結構工藝性、闡明如何操作的說明書、設計總結等等。1、 設計計算說明1.1該機主要有施彩輪傳動系統(tǒng)、氣動系統(tǒng)、真空系統(tǒng)、電器系統(tǒng)四部分組成1.2施彩輪傳動系統(tǒng)中施彩輪轉速得確定施根據(jù)以下試驗確定的：速度(m/s)0.10.20.30.40.50.6畫線效果滴釉苦釉粗細不均符合要求缺釉毛刺由表可知，畫線輪的最佳轉速為0.4m/s。1.2.1施彩輪電機功率及吸盤電機功率的確定施彩輪與被畫陶瓷器件的摩擦力矩為： 將P40，5，R0.03，f0.9代入上式（此數(shù)據(jù)為試驗所得）， M1.215（公斤米）由式中為電機所用總功率 n為電機減速輸出轉速 h為傳動效率由以上可得主機電機功率為0.17KW。1.3氣缸的選擇： 由于瓷器在燒成過程中不可避免產(chǎn)成變形現(xiàn)象，因而畫線輪要用適當壓力對瓷器實行壓緊。這一壓力在每平方厘米一公斤為好，總壓力為40公斤，畫出線條符合質量要求。而行程長度為20mm為最佳，因而我們取準力為40mm，行程為20mm的氣缸作為縱向氣缸。為了適應于陶瓷制品周邊的變形或者不規(guī)則形狀的畫線施彩輪靠輪必須始終給瓷器周邊以壓應力，因而試驗證明，橫向氣缸壓力應與縱向汽缸相等。為適應于魚盤等不規(guī)則瓷器的畫線工作，氣缸行程選擇80mm為宜。1.4該機真空度及抽氣速率的決定 以日用陶瓷中的16寸盤（本機所畫最大口徑的畫線盤）為例：1.5帶動摩擦輪的電動機的選擇畫線輪與瓷器之間應保證0.4m/s速度的純滾動，擬定主、從摩擦輪的轉速為： 由電動機到摩擦輪之間設置一級蝸桿減速器，其傳動比為62，則電動機的轉速范圍為：（18.863.7）62=11604000rpm,據(jù)此選擇直流電動機如如下： 型號： G4524 額定功率： 60KW 額定轉速： 4000rpm 額定電流： 2.5A 額定轉矩： 1.7KNm1.6主傳動路線：住傳動路線即由主電動機傳到主動摩擦輪的路線。由于帶傳動具有緩沖減震的作用，所以由主電動機帶動一級皮帶傳動。因為直流電動機轉速一般較高，在帶傳動以后選擇了一個標準蝸桿減速器，其輸出通過一個彈性套柱銷聯(lián)軸器傳到主動摩擦輪上，再經(jīng)從動摩擦輪帶動吸盤進行旋轉畫線工作。1.7實現(xiàn)瓷器自轉的傳動路線：摩擦輪電動機直接連接在一個蝸輪蝸桿減速器上。其輸入軸豎直，輸出軸水平放置且直接連接到主動摩擦輪，當從動摩擦輪與主動摩擦輪接觸時，動力便傳到從動摩擦輪繼而帶動吸盤旋轉。1.8主動蝸輪蝸桿減速器的選擇： 根據(jù)功率、傳動比及安裝要求，選擇主減速器為WS150蝸桿減速器。傳動比約為40，單向工作，JC=15%。1.9為實現(xiàn)畫線的全自動控制，對電器的基本說明 首先為了實現(xiàn)陶瓷品種的變化，為使陶瓷的畫線速度保持0.4m/s吸盤主電機應采用直流電機，采用控制電樞可調整流裝置，其基本控制如下： 2畫線機畫線質量總結以下因素對畫線質量有明顯影響：2.1畫線輪中心與此其重心在同一平面是取得最佳畫線效果的主要因素之一，如圖1.1，如果畫線輪偏上或偏下（相對瓷器中心比較）都會給瓷器帶上毛刺的線，影響產(chǎn)品質量。如圖1.2、圖1.3。2.2畫線輪偏擺對畫線的影響畫線輪由于安裝加工等引起的偏擺將使畫出線條成曲線狀，如圖1.42.3顏料的混合和黏度對畫線的影響畫線用顏料的黏度將給所畫線條帶來影響，如果黏度過大則所畫線條較標準寬度寬，如果黏庫過小則出現(xiàn)滴油現(xiàn)象，試驗表明最好是兩份介質和一份燃料構成。3目前存在的問題畫線機體積大；各調整螺栓不夠方便；整機藝術造型不夠理想。導軌的設計1概述1.1導軌的作用導軌主要用來支承和引導運動部件沿一定的軌跡運動并支承受運動部件的重量和工作載荷。兩個作相對運動的部件構成一對導軌副，其中不動的配合面成為固定導軌或靜導軌，運動的配合面稱為運動導軌過動導軌。在運動導軌和固定之間；一般只允許有一個自由度。1.2導軌應滿足的要求1.2.1導向精度幾何精度接觸精度1.2.2精度保持性1.2.3移動靈敏度1.2.4低速運動的平穩(wěn)性1.2.5抗振性和穩(wěn)定性1.2.6剛度1.2.7結構工藝性1.2.8對溫度變化的適應能力常用滑動導軌的類型、特點和應用類型工作原理和摩擦性導向精度靈敏度和定位精度低速運動平穩(wěn)性精度保持性抗振形和穩(wěn)定性應用特點滑動導軌普通滑動導軌整體式導軌副工作面是混合摩擦狀態(tài)，靜動摩擦系數(shù)相差較大，低速時摩擦系數(shù)隨速度增加而減小采用精銑、磨削或刮削可達到較高的幾何精度較差、不采用減磨措施時，定位精度為00.02mm低速時（160mm/min）易產(chǎn)生爬行導軌表面淬火可將耐磨性提高12倍好廣泛應用于普通精度的機械結構簡單，制造容易，維護簡便，成本低鑲裝式采用鑲銅、有色金屬或塑料板，改變導軌機體的摩擦特性，增加耐磨性一般比整體式的好一般比整體式好貼涂塑式由工程塑料做成動高貴表面，與金屬制靜導軌的摩擦系數(shù)較小，只隨著速度增加而略有增大，但承載能力較差用聚四氟乙烯軟帶時，定位精度可達0.002mm無爬行好廣泛用于粳米和重型機械，也常用于舊機器導軌的大修結構簡單，制造容易，維修簡便，制造成本較低，靜導軌常用鑲鋼式靜壓導軌液體壓力油通過節(jié)流器進入導軌承載面，在任何速度下均為液體摩擦狀態(tài)；油膜承載能力大油膜有均化誤差的作用，精度可達0.0010.006mm/1000mm微量位移定位精度為0.002mm摩擦系數(shù)很小，約為混合摩擦得1%低速運動時無爬行，定位精確，速度均勻導軌無磨損，精度保持性好油膜有吸振能力用于重型、大型和精密機械如數(shù)控機床制造復雜，調整較難，需要一套較復雜的供油系統(tǒng)氣體用壓縮空氣經(jīng)節(jié)流器進入導軌面內腔，形成厚約0.020.025mm厚的氣墊，比液體靜壓導軌摩擦系數(shù)下，承載能力低空氣介質有很好的冷卻作用，減小導軌熱變形，導向精度可達0.00025mm/300mm很高，定位精度可達0.125mm重復精度0.025很好，低速無爬行導軌副無金屬接觸，還可以用空氣起凈化作用可以采用花崗巖作機座，隔振性很好，由于氣隙很小，在很小振幅下已產(chǎn)生接觸，阻尼性強多用于數(shù)控機床三坐標測量機等需要一套供氣系統(tǒng)，承載能力低，空氣不需回收，不污染環(huán)境，結構比液壓體靜壓導軌簡單動壓導軌液體利用導軌面間的相對運動形成壓力油楔，將動導軌浮起，形成液體摩擦有“浮升”現(xiàn)象，導向精度一般一般不能用于低速起動和停止時速度低，不能建立動壓，有磨損油膜有吸振能力只適用于高速運動的主運動導軌，如立式車床的圓周運動導軌2滑動導軌結構設計2.1滑動導軌的截面形狀設計2.1.1直線滑動導軌的截面形狀設計直線運動導軌的截面，應保證運動部件只能沿直線方向運動，限制運動部件的轉動和橫向移動。當移動部件的尺寸較小，為細長條狀或行程較小時，可將導軌做成封閉性。選擇截面形狀時要注意：導軌磨損量隨表面比壓增加而增加，設計時應盡可能使導軌面垂直于外力的方向。導軌磨損后對導向精度的影響要小。2.2滑動導軌的間隙調整裝置為保證導軌的正常運動，運動件和支承件之間應保持適當?shù)拈g隙，間隙過小會增加摩擦力，操作費力還會加快磨損，間隙過大會使精度降低，甚至會產(chǎn)生振動。因此，除在裝配過程中應仔細地調整導軌的間隙外，在使用一段時間后因默存還需要重調。調整的方法：采用磨、刮相應地結合面或加墊片的方法，以獲取合適的間隙。用鑲條和壓板來調整導軌的間隙。2.2.1鑲條和壓板的結構型式用鑲條來調整矩形和燕尾形導軌的間隙時，把鑲條布置在受力較小的一側。壓板用于調整輔助導軌的間隙，并承受傾覆力矩。2.2.2導軌加緊裝置有些導軌（如非水平放置的導軌）在移動到預定位置后，要求將它的位置固定，為此采用專用的鎖（夾）緊裝置。常用的鎖緊方式有機械鎖緊和液壓鎖緊。2.3滑動導軌的材料和熱處理2.3.1對導軌材料的要求導軌材料應具有以下性能：良好的耐磨性在導軌不封閉，動導軌頻繁停歇和反向，潤滑不良的情況下，導軌面的磨損較快而且不均勻。在潤滑劑潔凈，不發(fā)生擦傷的條件下，處于混合摩擦區(qū)段的滑動導軌表面出現(xiàn)的磨損可以認為是正常磨損，滑動導軌材料匹配及其相對壽命值見表導軌材料匹配（動導軌/靜導軌）相對壽命鑄鐵/鑄鐵（均為普通鑄鐵）鑄鐵/淬硬鑄鐵鑄鐵/淬硬鋼淬硬鑄鐵/淬硬鑄鐵鑄鐵/鍍鉻或噴涂鉬鑄鐵1235104534良好的摩擦特性在設計滑動導軌時，為避免在低速運動時出現(xiàn)爬行，除合理選用潤滑劑及加強船東系統(tǒng)得剛度以外，要求導軌副的靜摩擦和動摩擦系數(shù)差以及滑動速度對動摩擦系數(shù)的影響都要小。良好的尺寸穩(wěn)定性導軌在加工和使用過程中，殘余應力引起的變形，溫度和溫度的變化，都會影響稽核尺寸的穩(wěn)定性。對于塑料導軌除了材料的線脹系數(shù)大，導熱性差，易吸濕外，還存在冷流性和常溫蠕變性大的問題。工藝性好，成本低。2.3.2常用的滑動導軌材料鑄鐵是應用最廣泛的滑動導軌材料，它具有良好的耐磨性和抗振性。鑄鐵導軌常與支承部件或支座制成一體。為增強導軌的抗磨損能力，可將鑄鐵導軌表面淬火，鍍鉻式噴涂相等。對于灰鑄鐵HT200或HT300，若采用高頻淬火，淬火前的硬度不應低于180HBS，淬火后可取4855HRC，硬化層厚度1.52.5mm，其相對壽命可提高12倍，這種方法工藝設備簡單，操作方便，淬火變形小。對于鍍鉻鑄鐵（或鋼）/鑄鐵導軌副，其鍍層厚度0.0250.05mm,硬度為6872HRC，耐磨性提高23倍。常用鑲裝材料有鋼、有色金屬、合金鑄鐵及工程塑料等。鋼材；又可分為冷軋彈簧鋼帶，經(jīng)高頻淬火的中碳結構鋼、滲碳鋼、氮化鋼、軸承鋼或特殊的工具鋼等。常用的工程塑料有酚醛夾布塑料，聚酰胺（尼龍）和聚四氟乙烯，改性聚甲醛等。2.4滑動導軌的技術要求2.4.1表面粗糙度刮研導軌刮研導軌可以達到最高的精度，同時還具有接觸好，變形小，表面可以存油的優(yōu)點。它的缺點是勞動強度大，生產(chǎn)率低，刮研導軌主要用于高精度機床和精密機械，在缺乏磨削設備時，也可用于精密機床和普通精度機床。磨削導軌磨削導軌可以達到較高的精度和表面粗糙度，生產(chǎn)率高，而且是加工淬硬導軌的唯一方法。2.4.2幾何精度單條的V形導軌，其幾何精度包括：導軌在垂直面內的直線度，導軌在水平面內的直線度，打soguibiaomiande扭曲。單條的平導軌，其幾何精度包括：導軌在縱向的直線度，導軌工作表面的平面度。與同一運動部件配合的兩條或兩條以上導軌（即導軌的組合），除注明各單導軌的精度外，還應注明各導軌之間的平行度，有時還要注明各導軌之間的平面度（扭曲）。幾個運動部件的各導軌組合之間，應注明其相互位置精度要求，如平行度或垂直度。在規(guī)定上述各項精度時，有時還要注明其誤差的方向性，例如“只許凸起”、“只許凹下”，“只許向下偏”等。使用說明書一、技術特征1、用途： 本機主要用于日用陶瓷盤類制品單線畫線。2、參數(shù)： 產(chǎn)品規(guī)格：盤類最大直徑406mm; 生產(chǎn)能力：812件/分； 總動力消耗：3KW； 最大描線彩帶寬度：6mm; 外型尺寸：130010001000（高寬厚）； 整機重量：500kg。二、基本結構本機主要有主機架、工作臺、施彩輪組件、真空泵、氣動系統(tǒng)、電氣部分組成。三、安裝將該機小心的立放在水平地面上，調整四螺栓，使其保持水平，然后清除防銹物。將壓縮機放在室外的專門小屋里，將出氣管與主機進氣管接通。用氣管接連真空泵與主機吸盤，用螺栓壓在機殼上銅線使其接地，接地銅棒不得低于一米，應保證安全。然后用380v電源及零件接到主機接線柱上。再接上壓縮機及真空泵電源，接線應嚴格按照電工安全操作規(guī)程進行，保證接線牢固、可靠、安全。四、調整將真空泵加足潤滑油，再將主機上的油霧氣及活動部位加油，檢查電器等是否安全可靠后，開動真空泵，空壓機，觀察其轉向是否正確，如不正確應立即糾正，然后打開氣閥觀察其動作的可靠性。把所需畫線瓷件，如8寸盤等放到吸盤上吸住后，開啟氣缸控制按鈕，這時橫向氣缸將施彩輪推到盤邊，連個定位滾靠到盤邊，縱向氣缸將畫線輪推靠盤上所要畫線的位置進行畫線，線畫至兩三圈后，縱向氣缸將施彩輪頭拉下，橫向氣缸將施彩機架立回原位，完成畫線過程。畫線時如果發(fā)現(xiàn)線條有一定缺陷，應考慮以下調整措施：畫線輪與盤所畫線位置的線速度是否保持一致，用速度表測量畫線輪速度，然后測量速度，再測量盤所畫線位置速度是否如同畫線輪一樣線速度。調整顏色黏度，直至達到理想線條。調整時間繼電器適當增減畫線圈數(shù)。調整畫線輪傳動電機的速度，達到理想為止。對于生產(chǎn)能力在5寸以下的盤類每分鐘8-12件為好，5寸以上盤類一般在每分鐘6-10件為好。畫線輪用完后，連同釉盒應一同卸下清洗干凈，并放到煤油中浸泡到下次使用為止。五、日常操作及維護1、本機開動前應檢查電器的安全性，是否有可靠的接地措施。傳動部件，真空泵，空氣壓縮機及動作磨損部位是否已加足潤滑油，所有調整部位是否緊固好。2、所有潤滑部位應每班注油一次。3、施彩頭，畫線輪、刮油器應每班清洗干凈，如果不用，應放到煤油里浸泡。4、所有部位應保持清潔。長期停用應防止銹蝕。標準化審查報告：1、畫線機應具備有關技術未見所規(guī)定的結構和使用性能，滿足 用戶的要求。2、畫線機各部位應靈活可靠。3、畫線機各氣動密封可靠，在規(guī)定的進氣壓力范圍內，各氣缸不得有漏氣現(xiàn)象。4、畫線機畫線輪在正常運轉情況下，其外圓跳動不得超過0.10mm，其兩側跳動不得超過0.15毫米。5、畫線機真空系統(tǒng)應可靠，陶瓷制品被吸住后不得有松動現(xiàn)象，去除真空后，制品應立即去下。6、畫線機外購件應符合現(xiàn)行有關標準的要求，并具有合格證明書。7、畫線機影響人身安全的部位應設置相應得保安設備。8、畫線機電器應安全可靠，畫線機外殼硬又可靠的接地措施。9、畫線機工作時不應有不正常聲響，噪聲聲壓級不得超過80dB(A)。10、畫線機在正常運轉情況下中修前運轉時間不得少于2000小時，大修前運轉時間不得少于4000小時，使用壽命不得少于十年。11、畫線機的鑄鋁件，應符合GB1173的規(guī)定。12、機械加工件應符合GB342.5-6標準的規(guī)定。13、畫線機施彩頭及擺動支架等鑄件上的澆口、冒口、飛邊、多肉、結疤、粘沙、結沙等應清除平整。14、畫線機表面不應有圖樣未規(guī)定的凸凹和粗糙不平等缺陷，外漏加工表面不允許有磕碰，擦痕等損傷。15、畫線機油漆應符合QB842.7標準的規(guī)定。帶傳動的設計計算1、確定設計功率2、選擇帶型根據(jù)及小帶輪轉速（取為2000rmp）,選擇Z型V帶。3、確定帶輪基準直徑取主動輪基準直徑并驗算帶速4、確定中心矩和帶長5、驗算小帶輪包角6、確定帶的根數(shù)Z 7、確定初拉力 8、計算壓軸力Q復位彈簧優(yōu)化設計1、一直條件：安裝高度安裝載荷最大工作載荷工作行程h=30.25mm，彈簧的工作頻率彈簧絲用油淬回火的50鋼絲，進行噴丸處理；工作溫度為20C。要求彈簧中徑為15mm20mm,彈簧總圈數(shù)為46;安全系數(shù)為1.2；設計一個具有重量最輕的彈簧結構方案。2、性能參數(shù)初選彈簧鋼絲直徑3mmd8mm,對應得抗拉強度可知其脈動循環(huán)疲勞極限為取可靠度為90%，則查得可靠性系數(shù)。溫度修正系數(shù)：。再考慮噴丸處理，按提高疲勞強度10%計算，得實際應用脈動循環(huán)疲勞極限為：彈簧平均載荷和載荷幅為 要求彈簧具有的剛度為 彈簧的最大形變?yōu)?3、設計變量取彈簧鋼絲直徑、彈簧中徑和彈簧總圈數(shù)為設計變量，即 并作為連續(xù)變量考慮。目標函數(shù)為彈簧的重量：4、約束條件根據(jù)對彈簧功能和結構的要求，可列出下列約束方程：由公式得疲勞強度的約束 根據(jù)旋繞比的要求，得約束 根據(jù)對彈簧中徑尺寸的要求，得約束 根據(jù)穩(wěn)定性條件，得約束 為保證彈簧具有足夠的剛度，要求彈簧的剛度與設計要求的剛度誤差小于1/100，由此得約束 ADAMS1.1虛擬樣機技術的研究范圍機械工程中的虛擬樣機技術有被稱為機械系統(tǒng)動態(tài)仿真技術，是國際上20世紀80年代隨著計算機技術的發(fā)展而迅速發(fā)展起來的一項計算機輔助工程（CAE）技術。工程師在計算機上建立樣機模型，為模型進行各種動態(tài)性能分析，然后蓋緊樣機設計方案，用數(shù)字化形式代替?zhèn)鹘y(tǒng)的實物樣機試驗。運用虛擬樣機技術，可以大大簡化機械產(chǎn)品的設計開發(fā)過程，大幅度縮短產(chǎn)品的開發(fā)周期，大量減少產(chǎn)品開發(fā)費用和成本，明顯提高產(chǎn)品質量，提高產(chǎn)品的系統(tǒng)及性能，獲得最優(yōu)化的創(chuàng)新的設計產(chǎn)品。因此，該技術一出現(xiàn)，立即受到了工業(yè)發(fā)達國家、有關科研機構和大學、公司的極大重視，許多著名制造廠商紛紛將虛擬樣機技術引入各自的產(chǎn)品開發(fā)中，取得了很好的經(jīng)濟效益。虛擬樣機技術的研究范圍主要是機械系統(tǒng)運動學和動力學分析，其核心是利用計算機輔助分析技術進行機械系統(tǒng)得運動學和動力學分析，以確定系及其各構件在任意時刻的位置、速度、和加速度，同時，通過求解袋鼠方程組去頂一起系統(tǒng)計其各構件運動所需的作用力及其反作用力。機械系統(tǒng)動力學自動分析軟件ADAMS（Autoumatic Dynamic Analysis Mechanical Systems）是美國MDI公司（Mechanical Dynamics Inc）開發(fā)的非常著名的虛擬樣機分析軟件。參考文獻1瓷器、精瓷與彩瓷 劉達權 北京：輕工業(yè)出版社，19842新型陶瓷 邱關明 北京：兵器工業(yè)出版社，1993.33設計材料與加工工藝 張錫 北京：化學工業(yè)出版社，2004.84陶瓷造型基礎 楊永善 北京：輕工業(yè)出版社，19855日用陶瓷工業(yè)學 李家駒 武漢：武漢工業(yè)大學出版社，19926高性能陶瓷論文集 郭景坤 北京：人民交通出版社，1998.57機械系統(tǒng)設計 朱龍根 北京：機械工業(yè)出版社，2001.88非標準設備機械手冊 張展 北京：兵器工業(yè)出版社9中國機電產(chǎn)品大辭典 北京：機械工業(yè)出版社10現(xiàn)代綜合機械設計手冊（下） 北京出版社11機械設計 譚慶昌，趙洪志 吉林科學技術出版社12材料力學 聶毓琴，孟廣偉 吉林科學技術出版社 13機械制造技術基礎 于駿一，張福潤 機械工業(yè)出版社 14機械原理 秦榮榮，崔可維 吉林科學技術出版社400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (724) 776-4841 Fax: (724) 776-5760 Web: www.sae.org SAE TECHNICAL PAPER SERIES 2002-01-1691 Developing Next Generation Axle Fluids: Part I Test Methodology to Measure Durability and Temperature Reduction Properties of Axle Gear Oils Edward S. Akucewich, James N. Vinci, Farrukh S. Qureshi and Robert W. Cain The Lubrizol Corporation International Spring Fuels & Lubricants Meeting & Exhibition Reno, Nevada May 6-9, 2002 The appearance of this ISSN code at the bottom of this page indicates SAEs consent that copies of the paper may be made for personal or internal use of specific clients. This consent is given on the condition, however, that the copier pay a per article copy fee through the Copyright Clearance Center, Inc. Operations Center, 222 Rosewood Drive, Danvers, MA 01923 for copying beyond that permitted by Sections 107 or 108 of the U.S. Copyright Law. This consent does not extend to other kinds of copying such as copying for general distribution, for advertising or promotional purposes, for creating new collective works, or for resale. Quantity reprint rates can be obtained from the Customer Sales and Satisfaction Department. To request permission to reprint a technical paper or permission to use copyrighted SAE publications in other works, contact the SAE Publications Group. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher. ISSN 0148-7191 Copyright 2002 Society of Automotive Engineers, Inc. Positions and opinions advanced in this paper are those of the author(s) and not necessarily those of SAE. The author is solely responsible for the content of the paper. A process is available by which discussions will be printed with the paper if it is published in SAE Transactions. For permission to publish this paper in full or in part, contact the SAE Publications Group. Persons wishing to submit papers to be considered for presentation or publication through SAE should send the manuscript or a 300 word abstract of a proposed manuscript to: Secretary, Engineering Meetings Board, SAE. Printed in USA All SAE papers, standards, and selected books are abstracted and indexed in the Global Mobility Database ABSTRACT Light trucks and sport utility vehicles (SUVs) have become extremely popular in the United States in recent years, but this shift to larger passenger vehicles has placed new demands upon the gear lubricant. The key challenge facing vehicle manufacturers in North America is meeting government-mandated fuel economy requirements while maintaining durability. Gear oils must provide long-term durability and operating temperature control in order to increase equipment life under severe conditions while maintaining fuel efficiency. This paper describes the development of a full-scale light duty axle test that simulates a variety of different driving conditions that can be used to measure temperature reduction properties of gear oil formulations. The work presented here outlines a test methodology that allows gear oil formulations to be compared with each other while accounting for axle changes due to wear and conditioning during testing. Results are shown from a variety of different axle configurations and loading conditions. This test method shows the importance of accounting for changes in the axle when comparing test results whenever severe conditions are experienced. INTRODUCTION Within the last few years, there has been a renewed desire to make fuel economy improvements in North Americas light trucks and sport utility vehicles (SUVs). Vehicle manufacturers have set aggressive fuel efficiency improvement objectives for these vehicles. Because of this, gear lubricants have been targeted to contribute fuel economy improvements over the current products used in these applications. This is not as easy as it may seem. In addition to acceptable fuel economy, gear lubricants are required to protect axle components under a variety of stressed conditions. These include high speed scuffing, low speed, high torque wear, corrosion and oxidation. In light truck and racing applications, gear oils must provide long-term durability and operating temperature control under extreme conditions, such as trailer towing or extended high speed applications. Higher operating temperatures for prolonged periods can adversely affect metallurgical properties and reduce fluid film thickness, both of which can lead to premature equipment failures. In our view, operating temperature is an important indicator of durability. While fuel economy is now the driving force in next generation lubricant development, it is clearly recognized that any improvements in fuel economy must not be at the expense of axle durability or performance. Fuel economy improvements can be measured via the U.S. EPA 55/45 driving cycles(1). Automotive manufacturers use this test to certify a vehicles fuel economy. This test can also be used to show fuel economy improvements in gear oil lubricants. Many manufacturers feel that stabilized operating temperature under the proper controlled conditions is an important indicator of the durability performance of a lubricant under severe conditions. In the case of operating temperature assessment, there exists no standard test method or methodology. Typically, when applied in a laboratory test stand a single axle is broken-in and then used repeatedly to evaluate many lubricants. Under severe conditions, the stabilized operating temperatures for a given reference oil decreases each time it is run in an axle. As the number of test runs on an axle increases the stabilized operating temperature of the reference oil is lower. This poses a problem when evaluating candidate lubricants. With a changing target, how can a lubricant be accurately evaluated? This paper describes a laboratory test method that accounts for test-to-test changes in the axle and gives the lubricant formulator an accurate way of comparing test results. In addition, common pitfalls of this method and operating guidelines will be described. 2002-01-1691 Developing Next Generation Axle Fluids: Part I Test Methodology to Measure Durability and Temperature Reduction Properties of Axle Gear Oils Edward S. Akucewich, James N. Vinci, Farrukh S. Qureshi and Robert W. Cain The Lubrizol Corporation Copyright 2002 Society of Automotive Engineers, Inc. 2 The remainder of this paper is divided into four parts. First, the test stand used to develop and utilize the test procedure is described. Second, the test methodology is discussed in detail. The third section focuses on presenting test results that demonstrate the usefulness of the test methodology. Finally, the last section summarizes the papers findings and offers some conclusions. PART 1 - AXLE TEST STAND CONFIGURATION This full-scale axle dynamometer test stand was designed and set up to simulate a variety of operating conditions. A schematic of the test stand is shown in Figure 1. This figure illustrates the axle rig and its major components. Figure 2 shows a picture of the test stand. Figure 1: Schematic of Axle Test Stand Input torque Output Torque Meter (2) Output Torque Meter (1) Box shroud + fan (optional) ENGINE: V8 GASOLINE DynamometerDynamometer Speed Increaser Speed Increaser 3 Figure 2: Photograph of Test Stand STAND CONFIGURATION - Power is supplied to the axle by a gasoline fueled 7.4 liter V8 engine through a heavy duty 4-speed automatic transmission that can be automatically shifted by the data acquisition and control (DAC) system. The axle used for lubricant evaluation is rigidly mounted to the stand. The power driven through the axle is absorbed by two air gap eddy current dynamometers. A speed increaser is placed between the axle wheel end and the dynamometer to boost output speed to the dynamometer for low speed applications. The stand used is flexible and with a quick change of torque meters and/or axle fixtures is able to accommodate a wide range of axle sizes, from small passenger vehicle axles to large on highway truck axles. TORQUE METERS - A single in-line torque meter integral to the drive shaft measures the input pinion torque to the axle. Two in-line torque meters measure the output torque from the axle to the dynamometers. One output torque meter has been placed between each axle wheel end and speed increaser. In addition, the torque meters used are the enhanced accuracy, DC operated models. This was done to increase and maintain a high degree of accuracy and repeatability. These torque meters are periodically dead weight calibrated to insure accurate torque measurements. AXLE COOLING AND TEMPERATURE MONITORING - Behind the axle a fan is positioned to provide airflow across the axle. This was done to simulate the actual airflow cooling experienced in field tests. The fan speed, size and position were selected to produce temperatures in the axle which match field test data for the axle being tested. In addition, two water spray nozzles are positioned around the axle. These spray nozzles are used for two purposes. First, they are used to control the lubricant temperature during axle break-in. Second, they provide protection against high axle lubricant temperatures. Depending upon the lubricant under evaluation, this test procedure has the potential of experiencing very high axle lubricant 4 temperatures. To protect the axle, high temperature limits have been put in place for each test stage. Another major concern is the measurement of the ambient air and axle lubricant temperatures. Thus, care was taken to properly position the thermocouples. The axle lubricant temperature is measured by a thermocouple positioned directly next to the axle ring gear. The thermocouple is held in place by a specially modified axle cover. The ambient air temperature is measured by placing a thermocouple in the air stream produced by the fan. Both thermocouples are periodically calibrated to insure accurate temperature measurements. DATA ACQUISITION AND CONTROL SYSTEM - A DSP Redline ADAPT / MRTP system is used to control the operation of the stand and to acquire data throughout the test. In addition to the ambient and lubricant temperatures, this system monitors and records additional temperatures (engine oil, transmission oil, dyno, gear box, fuel, and coolant), torques (input and two outputs), speeds (engine, pinion, axle shafts, and dynos) and axle efficiency (ratio of output torque to input torque) throughout the test. Data is logged periodically. This system controls the operation of the stand with five control loops. Two control loops are used to maintain the desired pinion speed. This is done by modulating each dynamometer current to achieve a desired pinion rpm. The load on the pinion is maintained by adjusting the engine throttle. A fourth control loop is used to control the axle lubricant temperature during axle break in and to prevent high temperatures from damaging the axle during lubricant evaluations. Finally, a fifth control loop is used to insure that the automatic transmission is running each test stage in the appropriate gear. It is important that the automatic transmission is operating in the proper gear. Some of the test stages during this test run at relatively high loads. Premature failure will occur if the transmission does not operate in the appropriate gear for a given test stage. PART 2 - TEST METHOD In general, the evaluation of the lubricants durability was assessed by determining its stabilized operating temperature and axle efficiency at a number of discrete speed / torque conditions. The test procedure used is described below. REFERENCE OILS - Reference oils are critical to this test methodology. For the development of this test procedure and evaluation of lubricants, two reference oils were used. The fluids used as reference oils are as follows: Good Reference: Synthetic SAE 75W-140 Poor Reference: Synthetic SAE 75W-90 The good reference has been shown to provide outstanding performance in a wide variety of severe service applications. This fluid provided excellent temperature reduction in a controlled severe duty field test. This reference oil is used to break-in the axle and is periodically tested on a given axle to track any changes that might occur in stabilized operating temperatures. The poor reference was also field tested and did not provide the same level of durability or temperature reduction in severe conditions as the good reference. Testing has shown however that this lubricant provides measurable fuel economy benefits. This reference oil is used to verify that the test procedure can distinguish between oils that provide different levels of performance in the field. AXLE BREAK-IN - Before an axle can be used for lubricant evaluation, a break-in procedure is run. This procedure consists of a series of controlled load and speed conditions. The axle lubricant temperature is controlled throughout the break-in procedure where it is not allowed to exceed 250F (121C). The good reference oil is used for the break-in procedure. Running an adequate break-in is critical in preparing the axle for accurate lubricant evaluations. Once broken in an axle can run multiple candidate lubricant evaluations. TEST STAGES - Following the break-in procedure, candidate lubricants are evaluated by determining the stabilized operating temperature and efficiency at five combinations of speed and loads (stages) to approximate different severe operating conditions. Table 1 outlines the test conditions used. 5 Table 1 Durability and Operating Temperature Test Conditions STAGE GENERAL CONDITION CORRELATION I High torque / low speed Heavy Load - Start-Up II Moderate torque / high speed High Speed - Flat Surface III Moderate torque / moderate-high speed Heavy Load - Flat Surface IV Moderate-high torque / moderate speed Heavy Load - Moderate Grade V High Torque / low-moderate speed Heavy Load - Steep Grade Each of the load stages is run until a stabilized lubricant temperature is achieved. This typically takes 1.5 to 2.5 hours. Once a stabilized temperature is reached, the next test stage is started. This cycle is repeated until all test stages have been evaluated. At the completion of each test stage, the ambient air temperature, stabilized lubricant temperature and stabilized axle efficiency is recorded(2). AMBIENT AIR TEMPERATURE ADJUSTMENTS - It has been observed that changes in ambient air temperature affect the stabilized operating temperature of the axle lubricant. Since this test method was run in a laboratory where the ambient air temperature may vary, changes in ambient air temperatures must be accounted for. Adjusting the axle lubricant temperature to account for ambient air temperature changes is done by normalizing the axle lubricant temperature relative to an ambient air temperature of 80F with the following equation: Tcorrected = Taxle + (80F Tambient) Where, Tcorrected = lubricant temperature (F) corrected for the ambient air temperature. Taxle = measured lubricant temperature (F). Tambient = measured ambient air temperature (F). Before applying any of the methodology described below, the axle lubricant temperature is adjusted to account for ambient air temperature differences. REFERENCE TEMPERATURE CHANGES - As the number of tests run on an axle increases, the stabilized operating temperature for a given load condition of any single oil is lower. This fact poses a problem when evaluating a candidate lubricant. To solve this problem in the past, reference oil is tested periodically and the candidate result is compared to the last reference test result. However, if the reference test temperature gets lower after each test run, comparing the candidate to the last reference result will make the candidate seem better than it actually is relative to the reference. Figure 3 shows the change in stabilized operating temperatures for stage V conditions on a test axle when the good reference oil is tested. The stabilized operating temperature goes down as the number of test runs on the axle increases. For this test procedure, this trend occurs on all 5 test stages. 6 Figure 3: Stabilized Operating Temperature For the Good Reference Oil Over the Life of a Test Axle Under Stage V Conditions REFERENCE TARGET TEMPERATURE - To make a fair comparison between a reference and a candidate, the reference oils stabilized operating temperature used for comparison should be adjusted for the number of runs made on the axle. This adjustment must be done for each test stage and lubricant evaluated on an axle. The adjusted reference oil temperature or “reference target temperature” can then be compared to the candidate oils stabilized operating temperature for the load stage in question. Based on the reference test data, an equation for each test stage can be generated taking into account the reduction in the reference stabilized operating temperature as the number of test runs increases on an axle. This must be done for each axle tested. Once generated, candidate results can be accurately compared to reference oil performance. Figure 4 shows a curve fitted to the stabilized operating temperatures of the good reference oil for Stage V test conditions. Stabilized Axle Temperature Good Reference Oil Stage V Conditions 180 200 220 240 260 280 Increased Axle Runs Corrected Temperature (Deg F) 7 Figure 4: Curve Fitted To Stabilized Operating Temperature Results for Good Reference Oil on a Test Axle Under Stage V Conditions From the equation developed in Figure 4, a reference target temperature can be calculated for each test run on the axle for each test stage. Candidate test results can now be accurately compared to reference test results. In addition, this method allows the formulator to more accurately compare results that were tested on different axles since your comparison is relative to the reference oil. AXLE EFFICIENCY CHANGES - Just as with the stabilized temperature, a similar effect occurs with the axle efficiency measurements on test axles. The axle efficiency gradually increases as the number of tests on an axle increases. Figure 5 shows the changes in the axle efficiency and the reference target efficiency equation developed from the test results. Stabilized Axle Temperature Good Reference Oil Stage V Conditions y = 0.0172x2 - 1.4508x + 237.02 R2 = 0.9302 200 210 220 230 240 250 260 Increased Axle Runs Corrected Temperature (Deg F) 8 Figure 5: Stabilized Axle Efficiency Values For the Good Reference Oil Over Life of a Test Axle Under Stage II Conditions It has been our experience with this test procedure that the stabilized axle efficiency for any test stage is inversely proportional to the stabilized operating temperature. The higher the efficiency, the lower the operating temperature. Thus our primary focus in the paper is on the operating temperatures and not the axle efficiencies. The test methodology described in this paper can be applied to both. ASSESSMENT OF TEST REPEATABILITY - Test repeatability can be estimated from the reference test results on each axle. This is done by comparing the differences between the actual stabilized operating temperature and the calculated reference target temperature for each reference test in an axle for a given test stage. For example, the test repeatability was calculated to be 5.9F for Stage V conditions shown in Figure 4. Our experience has been that repeatability estimates range from 0.5 to 8.0 F depending upon the test stage run, axle used and lubricants tested.(3, 4) The test repeatability on any given axle is greatly affected by the quality of the candidate oils tested. Running a poor quality oil affects the results of the tests that run on the axle after it finishes. This introduces additional variability in the test stand. Thus it is important to run go