旋耕機刀片專用磨損試驗機的研究與設計
旋耕機刀片專用磨損試驗機的研究與設計,旋耕機刀片專用磨損試驗機的研究與設計,旋耕機,刀片,專用,磨損,試驗,實驗,研究,鉆研,設計
任務書
設計
課題名稱
旋耕機刀片專用磨損試驗機的研究與設計
學生姓名
院(系)
工學院
專 業(yè)
機械設計與制造及其自動化
指導教師
職 稱
教授
學 歷
博士
畢業(yè)設計要求:
1. 好學上進,能吃苦耐勞,刻苦專研,有相應專業(yè)知識,具備獨自工作的能力;
2. 按時完成畢業(yè)設計內(nèi)容,方案切實可行;
3. 獨立繪制裝配圖和零件圖;
4. 圖紙量不少于1.5張A0;
5. 工作量符合我院畢業(yè)設計的要求;
6. 完成電子文檔,并打印裝訂成冊。
畢業(yè)設計內(nèi)容與技術(shù)參數(shù):
1. 畢業(yè)設計的內(nèi)容為設計一旋耕機刀片專用磨損試驗機的研究與設計;
2. 通過查閱相關(guān)資料發(fā)現(xiàn)在以往的旋耕機刀片選用過程中,都沒有很嚴格的安裝刀片的耐磨性來選擇,只是按照品牌的好壞來選擇刀具;
3. 確定及選擇電動機、V帶等型號和傳動比的分配;
3.有關(guān)技術(shù)參數(shù)參見機械設計手冊。
畢業(yè)設計(論文)工作計劃:
1. 首先查閱有關(guān)于旋耕機與磨損機的相關(guān)資料,對旋耕機與磨損機有大體的了解,熟悉 其工作原理;
2. 通過思考和交流以及考察發(fā)現(xiàn)磨損機的不足,特別是關(guān)于專用刀具的磨損機;
3. 通過給出總體方案,畫出工作草圖;
4. 對旋耕機刀片專用磨損機有全面的了解后確定其整體結(jié)構(gòu)和主要零部件;
5. 計算電動機功率及帶輪、齒輪型號并確定各零件的基本尺寸、基本偏差和IT等級;
6.編寫設計說明書;
7.繪制裝配圖.
接受任務日期 2012 年 12 月 28 日 要求完成日期 2012 年 5 月 10日
學 生 簽 名 年 月 日
指導教師簽名 年 月 日
院長(主任)簽名 年 月 日
設計材料
題 目
旋耕機刀片專用磨損試驗機的研究與設計
專 業(yè)
機械設計制造及其自動化
學生姓名
材 料 目 錄
序號
附 件 名 稱
數(shù)量
備注
1
畢業(yè)設計論文
1
2
零件圖
11
3
總裝圖
1
4
設計任務書
1
二〇一二年 五月
..
UNIVERSITY
設 計
題目: 旋耕機刀片專用磨損試驗機的研究與設計
學 院:工學院
姓 名:
學 號:
專 業(yè):機械設計制造及其自動化
年 級:
指導教師: 職 稱:教授
二○一二 年 五 月
ii
摘要
隨著農(nóng)業(yè)發(fā)展,旋耕機的研究與生產(chǎn)也越來越廣泛。各種用途的旋耕機都相繼面世。旋耕機的用途的不同自然是有他們的主要工作部位決定的,因此旋耕機刀片的研究就尤為重要重要,各種各樣的道具有外型不一也有同一系列不同材料的刀具。對于一臺旋耕機而言或者說對于生產(chǎn)而言選取一款最適合的刀具是重中之重。所以相應的對比刀具的性能才是選擇的關(guān)鍵。通過我對市場的有關(guān)方面的調(diào)查和了解發(fā)現(xiàn),先進社會并沒有相關(guān)的對比刀具性能的機器,這對于需要選用刀具的單位或者個人而言,沒有明確的信息供他們合理的選著。針對現(xiàn)狀我設計了一臺旋耕機刀片專用磨損試驗機供對比刀具性能實用。
我所設計的旋耕機刀片專用磨損試驗機的工作原理是利用電動機提供動力帶動鏈接轉(zhuǎn)軸的帶輪傳動,使軸高速轉(zhuǎn)動,從而使得軸上的刀具與磨料高速摩擦,通過對比一段時間的后刀具的磨損情況來對比刀具的耐磨性。
本設計的主要特點在于所設計的機構(gòu)非常簡單,實用性較強,生產(chǎn)此磨損試驗機難度很小。而且此機械工作原理以及操作簡單,其所用的材料普通,所以本機的制造成本不僅很低而且適用性很強,并且對于使用者基本上沒有技術(shù)要求。本設計利用Auto CAD軟件繪制相關(guān)的圖紙,并用Pro/ Engineer軟件進行實體建模。
關(guān)鍵詞:磨損機、旋耕機刀片、磨料
Abstract
Agricultural development, the the rotavator the research and production is also more extensive. The various uses of rotary tiller have been published. The rotavator the use of different natural is their main work site decision, rotary tiller blade is particularly important to a wide variety of Tao has a shape different tool of the same series of different materials. For a rotavator or select a most suitable tool is the most important in terms of production. So the key to the performance of the comparison tool is selected. By the market parties to investigate and understand advanced social comparison tool performance machine for the unit or individual of the need to use the tool, there is no clear message for their election. For the status quo, I designed a rotary tiller blades wear testing machine for comparison tool performance and practical.
I designed the rotary tiller blade for wear testing machine works by the use of electric motor drive link shaft pulley transmission, axis high-speed rotation, so that the axis of the tool and the abrasive high-speed friction, by comparing the period of time the wear of the tool to compare the wear resistance of the tool.
The main features of this design is that the institutional design is very simple, practical strong, difficult to produce this wear test machine is very small. And mechanical work as well as simple operation, and its use of ordinary materials, the manufacturing cost of the machine is not only low but also the applicability of a strong and virtually no technical requirements for the utility. The design using Auto CAD software to draw the relevant drawings and Solid Modeling with Pro / Engineer software.
Key words: wear machine, rotary tiller blade, abrasive
目錄
1 緒論 1
1.1 引言 1
1.2 適用范圍及特點 1
2 設計方案的確定和關(guān)鍵技術(shù)的解決方法 2
2.1 總體結(jié)構(gòu)與主要工作部分 2
2.1.1 機架 2
2.1.2 外形 2
2.1.3 與機架有關(guān)的部分 3
2.2 傳動系統(tǒng) 3
2.2.1 V帶輪傳動 3
2.2.2 軸的設計 4
2.2.3 傳動系統(tǒng)示意圖 4
3 本機工作原理與操作方法 6
3.1 工作原理 6
3.2 操作方法 6
4 本機的結(jié)構(gòu)特點與先進性 7
5 本機的特征 8
6 計算部分 9
6.1 動力計算、選配電機 9
6.2 V帶輪傳動設計及計算 9
6.3 軸的分析 11
6.3.1 軸的選材 11
6.3.2 軸的校核 12
6.4 軸承的選用與校核 17
參考文獻: 19
致謝 20
1 緒論
1.1 引言
自古以來,有很多人試圖以機械力代替人力和畜力進行耕作。但直到19世紀歐洲進入蒸汽機時代后,才使動力型農(nóng)業(yè)機械的誕生成為可能。19世紀30年代,已有人開始研究用蒸汽車輛牽引農(nóng)機具進行田間作業(yè)。但當時所能造出的蒸汽機牽引車輛(即蒸汽拖拉機的前身)猶如一個水火車頭,它即使不陷在田里,也會把土壓得很實,根本無法耕種,此后人們一直改進創(chuàng)新一直到1920年以后旋耕機才正式走進勞動人名的生活。
目前,隨著農(nóng)業(yè)機械化的飛速發(fā)展,我國農(nóng)村耕地基本上采用旋耕機。當前,我國農(nóng)村所使用的旋耕機有各種各樣的的旋耕機,主要區(qū)別還是在于他們的刀具不同,而且同一外形的刀具也有很多不同的生產(chǎn)廠家制造,所以他們的各種性能也會不同。因此為了研究各種刀具的性能我針對這一情況設計出了一款中小型旋耕機刀具專用磨損試驗機。本設計的主要特點在于所設計的機構(gòu)非常簡單,實用性較強,生產(chǎn)此磨損試驗機難度很小。而且此機械工作原理以及操作簡單,其所用的材料普通,所以本機的制造成本不僅很低而且適用性很強,并且對于實用者基本上沒有技術(shù)要求。
1.2 適用范圍及特點
本產(chǎn)品適用于研究同一系列不同型號的旋耕機刀具性能對比試驗,其工作效率高,生產(chǎn)成本低廉,結(jié)構(gòu)簡單,便于操作。用戶可以自行更換部分簡單的零部件。
2 設計方案的確定和關(guān)鍵技術(shù)的解決方法
2.1 總體結(jié)構(gòu)與主要工作部分
2.1.1 機架
目前國內(nèi)外機械的機架一般有兩大類,分別是整理鑄造和焊接式機架。
整體鑄造機架:其整體性和剛性好,節(jié)省切削加工工時,而且產(chǎn)品質(zhì)量穩(wěn)定,可以說百年不壞。但是,機架鑄造困難,而且鑄造技術(shù)要求高,成本高。
焊接式機架:其生產(chǎn)周期短, 重量輕,成品率高。但是, 焊接技術(shù)要求高, 焊接后產(chǎn)生變形及應力及中, 必須進行熱處理以消除應力及中。
綜合上面兩種機架的優(yōu)缺點以及該磨損試驗機的工作要求,因此本實驗采用焊接式機架。
機架的材料:機架的材料應根據(jù)結(jié)構(gòu)、工藝、成本、生產(chǎn)批量和生產(chǎn)周期等要求正確選擇,常用的有:
(1) 鑄鐵:容易鑄成復雜的機械零件;價格較便宜;鑄鐵的內(nèi)摩擦大,有很好的抗震性。其缺點是單件成本較高;鑄件易產(chǎn)生廢品;質(zhì)量不易控制;鑄件的加工余量大,機械加工費用大。
常用的灰口鑄鐵有兩種:HT200適用于外形簡單,單位壓力較大的導軌或彎曲應力較大的床身等;HT150流動性較好,但機械性能稍差,適用于機型復雜而載荷不大的機座。若灰口鑄鐵無法滿足耐磨性要求,應采用耐磨性鑄鐵。
(2)鋼:用剛才焊接成機架。鋼的彈性模量比鑄鐵大,焊接機架的壁厚較薄其重量比同樣剛度的機座約輕20%—50%;在單件小批量生產(chǎn)的情況下,生產(chǎn)周期較短,所需設備簡單;焊接機架的缺點是鋼的抗震性較差,在結(jié)構(gòu)上需采取防震措施;鉗工工作量較大;成批生產(chǎn)時成本較高。
綜上:選用HT200的灰口鑄鐵滿足該機器的機架要求。
2.1.2 外形
機座的典型結(jié)構(gòu)主要有三種:
1 方形截面機座
結(jié)構(gòu)簡單,制造方便,箱體內(nèi)有較大的空間安放其他的部件;但剛度稍差,宜用于載荷較小的場合。所以機座應選擇合適的壁厚、筋板和形狀,以保證在重力、慣性力和外力的作用下,有足夠的剛度。
2 圓形截面機座
結(jié)構(gòu)簡單、緊湊,易于制造和造型設計,有較好的承載能力。
3 鑄鐵板裝配式機座
鑄鐵板裝配機構(gòu),適用于局部性狀復雜的場合,它具有生產(chǎn)周期短、成本低以及簡化木模形狀和制造工藝等優(yōu)點。但剛度較整體箱體機座的差,且加工和裝配工作量大。
考慮上訴原因,本機使用的是密封的工作環(huán)境,即把軸與磨料放于一個橫向鐵桶中,使工作部分完全密封。
它的優(yōu)點在避免了工作時磨料的飛濺以及保護了軸長期處于外部壞境而產(chǎn)生的負面影響。而且該機器操作簡單方便,更加加強的該機器的適用性。
2.1.3 與機架有關(guān)的部分
該機器除去機架部分外還有一根軸鐵桶以及磨料。在機架底部會有兩個圓弧型凹槽,該凹槽半徑與鐵通外半徑相同,很好的起到了支撐作用。工作時磨料是位于鐵桶內(nèi),軸是直接穿過鐵桶的兩端與位于桶外面的軸承鏈接。軸承安裝的兩邊的支架上。
2.2 傳動系統(tǒng)
2.2.1 V帶輪傳動
V帶輪是通過電動機帶動的,而V帶輪帶動軸轉(zhuǎn)動,由旋耕機工作數(shù)據(jù)可知軸的轉(zhuǎn)速為270r/min,但是此實驗需要快速得出結(jié)果,故使該機器軸的轉(zhuǎn)速為旋耕機正常工作時轉(zhuǎn)速的2.5倍到3倍,即775~810r/min。這個設計轉(zhuǎn)速不僅加快刀具磨損可以得到實驗結(jié)果,同時也不至于轉(zhuǎn)速度太快而造成各種不利影響。由小型旋耕機的功率大至可以推斷此機器功率大至介于3.0~5.5kw,初步選取的電動機轉(zhuǎn)速為1500r/min。因此可以確定傳動比大至為1.85~1.94,具體參數(shù)后面會詳細計算確定。
2.2.2 軸的設計
本實驗的傳動軸采用的結(jié)構(gòu)與旋耕機的刀軸結(jié)構(gòu)類似。即在圓柱的外表面焊接刀座,兩端接軸承。這樣就合理的解決了刀具的安裝問題。為減輕質(zhì)量軸的中心可采用通孔,再保證的正常工作的情況下盡量減輕軸的質(zhì)量,這樣也可以減少能量的損耗。
2.2.3 傳動系統(tǒng)示意圖
此機器的傳動原理就是靠電動機帶動V帶輪,從而使得軸轉(zhuǎn)動,傳動示意圖如下:
3 本機工作原理與操作方法
3.1 工作原理
本機的工作原理是V帶輪快速帶動轉(zhuǎn)軸,使得軸做快速的回轉(zhuǎn)運動,軸上的刀具下半部分侵入磨料的當中,因此使得刀具與磨料發(fā)生摩擦,通過較長一段時間的摩擦看最后各個刀具的磨損量,從而得到自己需要的數(shù)據(jù)。本實驗的磨料選擇細沙,他可以通過可開口的鐵桶放入,實驗前后可對細沙更換。軸上的刀具裝在一個支架上面,做其他實驗時更換不同的到的刀片就可。
3.2 操作方法
設備安裝好后,檢查一下各部件是否穩(wěn)定。先把不同廠家的刀具的安裝在軸的刀架上面,利用螺釘螺母把刀具緊固,然后通過鐵桶的開口部分注入細沙,使得細沙均勻分布,細沙的深度需滿足刀具的下半部分可以完全侵入,完成此工作后把鐵桶開口部分關(guān)閉。確認無誤后啟動電動機,當機器工作時觀察一段時間,看看是否正常工作,如果工作出現(xiàn)問題應立即關(guān)閉電動機從新檢查各部位是否出現(xiàn)問題,從而改正。機器正常工作后,操作人員可設置一個工作時間,等到時間之后再把電機關(guān)閉即可。
4 本機的結(jié)構(gòu)特點與先進性
本機器是綜合各方面因素才設計的,目前社會上還沒有出現(xiàn)過旋耕機刀片專用的磨損試驗機,此設計可以說是一個創(chuàng)新,是史無前例的。本機機架部分外形適用簡單,即使安裝各配件后整理仍然簡單,而且各部位涉及的零件都可以直接選用標準件,有事的生產(chǎn)的成本的大大的降低了。綜上:本機的結(jié)構(gòu)簡單、緊湊,實用性強,裝、拆、檢修方便,而且各個結(jié)構(gòu)的尺寸都比較小,生產(chǎn)此機器的成本低。并且此機器是旋耕機刀片專用磨損試驗機,針對性強,為各個廠家選擇最合適的旋耕機刀片具有歷史性的意義。
5 本機的特征
綜上所述,本機具有以下特征:
1、傳動簡單,中途損耗小誤差??;
2、電動機的功率較小,節(jié)省工作能耗;
3、軸傳動采用V帶輪傳動;
4、工作部位采用整體外殼結(jié)構(gòu),密閉性好,噪音小;
5、本機的結(jié)構(gòu)簡單、緊湊,實用性強,裝、拆、檢修方便;
整理機型如下圖:
6 計算部分
6.1 動力計算、選配電機
由經(jīng)驗可知,該實驗可選取電動機:型號-61-4 同步轉(zhuǎn)速1500r/min 滿載時1460r/min 質(zhì)量164kg 功率13kw 功率因數(shù)0.88
6.2 V帶輪傳動設計及計算
V帶輪傳動工作時,帶的兩側(cè)面是工作面。由于拉力是變化的,同時引起帶寬尺寸的改變,從而使帶沿輪槽做徑向移動。在從動輪上,帶由松變緊,拉力逐漸增大,帶向槽內(nèi)運動,主動輪則相反。因此,V帶輪傳動有周向滑動和徑向滑動同時存在,相應的都有周向和徑向的摩擦力的存在。
定V帶輪型號和帶輪直徑
工作情況系數(shù) 由表11.5
計算功率 (式11.19)
選帶型號 由圖11.15 B 型
小帶輪直徑 由表11.6 取大帶輪直徑 (式11.15)
(設) 取mm
大帶輪轉(zhuǎn)速
計算帶長
求
求
初取中心距 mm
帶長 (式11.2)
基準長度 由圖11.4
中心距和包角
求中心距 (式11.3)
+ 683mm
小輪包角 (式11.4)
求帶根數(shù)
帶速
傳動比 i i
帶根數(shù) 由表11.9 由表11.7
由表11.12 由表11.11
取z=3
求軸上載荷
張緊力 (式11.21)
=500329.7
(由表11.4 q)
軸上載荷 (式11.23)
帶輪的結(jié)構(gòu)如下圖:
6.3 軸的分析
6.3.1 軸的選材
軸是機械中重要的零件之一,主要用于傳動零件傳動運動和動力。工作時主要受交變彎曲和扭轉(zhuǎn)應力的復合作用,有時也受拉壓應力;軸與軸上零件有相對運動,相互間存在摩擦和磨損;軸在高速運轉(zhuǎn)過程中產(chǎn)生振動,是軸承受沖擊載荷;多數(shù)軸在工作工程中,常常要承受一定的過載載荷。
長期交變載荷作用易導致疲勞斷裂(包括扭轉(zhuǎn)疲勞和彎曲疲勞斷裂);承受大載荷和沖擊載荷會引起過量變形、斷裂;長期承受較大的摩擦,軸頸及花鍵表面易出現(xiàn)過量磨損。
良好的力學綜合性能,以防過載斷裂、沖擊斷裂;高疲勞強度,降低應力集中敏感性,以防疲勞斷裂;足夠的剛度,以防工作過程中,軸發(fā)生過量彈性變形而降低加工精度;表面要有高硬度、高耐磨性,以防磨損失效;特殊性要求-----如高溫中工作的軸,抗蠕變形能要好;在腐蝕性工作介質(zhì)的軸,要求耐腐蝕性能好等。
由以上原因,我所選取的軸使用的材料為合金鋼。
合金鋼
6.3.2 軸的校核
軸的外形以及尺寸大至如下:
圖中用于標注的虛線與軸中心線的交點為軸承、刀具以及V帶輪等部件的中心點。下面的計算所用的距離均以各個部件的中心點為準。
由經(jīng)驗可知,旋耕機刀片磨損過程中所損耗的能量占總能量的,在前面我們已經(jīng)計算出V帶輪作用在軸上的載荷為,下面我們算出刀具所受到的力。計算如下:
(為刀具進入磨料部分的中點的速度)
(為軸的角速度,r為軸的中心到刀具入料部分中點的距離,取)
(n為V帶輪轉(zhuǎn)速800r/min)
代入數(shù)據(jù)得:
當帶輪的中心線垂直時,軸所受的力為最大,下面的計算即為該狀況下軸的受力情況已經(jīng)載荷的計算和校核。
通過受力分析,繪制軸的彎扭矩圖,對危險界面進行校核。簡化軸上載荷如圖:
軸的總長度為1045mm,合金鋼的密度為
軸的體積為
則軸的總重量
m=
代入數(shù)據(jù)得:
在YOZ平面內(nèi),左右軸承的力設為,通過兩軸承的位置我們可以繪制YOZ平面的力學模型關(guān)系,位置和方向如圖所示:
則有以下數(shù)學關(guān)系:
求得:
則與圖示方向相反,與圖示方向相同
在XOZ平面內(nèi),左右軸承的力設為,通過兩軸承的位置我們可以繪制XOZ平面的力學模型關(guān)系,位置和方向如圖所示:
則有以下數(shù)學關(guān)系:
(前面已算得)
求得: 則說明的實際方向與圖示方向相反。
由上面所有數(shù)據(jù)可畫出如下所示彎矩圖,扭矩圖:
由彎矩圖、扭矩圖可知A點為危險截面。對A點進行校核計算:
因為此轉(zhuǎn)矩為脈動轉(zhuǎn)矩,取
代入數(shù)據(jù)得
代入數(shù)據(jù)可得:
對于A點則有:
(A處直徑)
代入數(shù)據(jù)可得:
因為
滿足強度要求。
所有軸承選用上述的合金鋼符合要求。
6.4 軸承的選用與校核
考慮到軸的直徑為50mm,并且中間鐵桶由支架支撐,對軸承沒有力的作用,選用單列向心球軸承,型號為0000,輕(2)窄系列210型。其參數(shù)為:
額定動負荷 額定靜負荷
(1)計算軸承的當量載荷P:
由式:知,對不受軸向載荷的球軸承,
;
由前面計算已知: ;
;
得
(2)校核計算
軸承的計算額定功率載荷,它與所選用的軸承型號的基本額定載荷值必須滿足下式的要求:
;
為壽命指數(shù),球軸承;
為軸承的預期使用壽命,查表;
解得:
綜上:軸承滿足使用要求,選用合理。
參考文獻:
[1] 趙衛(wèi)軍,任金泉.機械設計基礎(chǔ)課程設計[M].北京.科學出版社,2011.(11)
[2] 鄭文緯,吳克堅.機械原理[M].第七版.北京:高等教育出版社,1997.7
[3] 陳香久,陳一飛.小型電動機原理使用維修400問[M].北京:中國農(nóng)業(yè)出版社,1998:110(帶輪選擇)
[4] 孔凌嘉.簡明機械設計手冊[M].北京:北京理工大學出版社,2008.2
[5] 邱宣懷,郭可謙,吳宗澤,等.機械設計[M].第四版.北京:高等教育出版社,1997:118
[6] 中國農(nóng)業(yè)機械化科學研究院.實用機械設計手冊(上)[M].北京:中國農(nóng)業(yè)機械出版社,1985.7
[7] 劉自然,李東梁,武文斌.輥式磨粉機磨輥的受力計算和強度分析[J].糧食與飼料工業(yè)報,2009,NO.12
[8] 辛長平.簡明電動機技術(shù)手冊[M].沈陽:遼寧科學技術(shù)出版社,2010.2
[9] 卜嚴.機械傳動裝置設計手冊[M].北京:機械工業(yè)出版社,1998.12
[10] 上海電器科學研究院[M].北京:機械工業(yè)出版社,2003.1
[11] 成大先.機械設計手冊[M].北京:化學工業(yè)出版社,1998
[12] 劉鴻文.材料力學[M].第四版.北京:高等教育出版社,2004.1
[13] 中國農(nóng)業(yè)機械化科學研究院.實用機械設計手冊(上)[M].北京:中國農(nóng)業(yè)機械出版社,1985.7
[14] 蔣曉、沈培玉、苗青.AutoCAD2008中文版機械設計標準實例教程.北京:清華大學出版社.2008.
[15] 何銘新、錢可強.機械制圖.5版.北京:高等教育出版社.2008.4
[16] 哈爾濱工業(yè)大學理論力學教研室.6版.北京:高等教育出版社.2004.4
[17] 劉混舉、趙河明、王春燕.機械可靠性設計.北京:國防工業(yè)出版社.2010.6
[18] 金清肅、范順成、范曉珂.機械設計課程設計.武漢:華中科技大學出版社.2006.2
[19] 王慧、呂宏、王連明.機械設計課程設計.北京:北京大學出版社.2011.2
致謝
在此論文撰寫過程中,要特別感謝我的導師張廬陵教授的指導與督促,同時感謝他的諒解與包容。沒有張老師的幫助也就沒有今天的這篇論文。求學歷程是艱苦的,但又是快樂的。感謝我的班主任曾一凡老師,謝謝他在這四年中為我們?nèi)嗨龅囊磺?,他不求回報,無私奉獻的精神很讓我感動,再次向他表示由衷的感謝。在這四年的學期中結(jié)識的各位生活和學習上的摯友讓我得到了人生最大的一筆財富。在此,也對他們表示衷心感謝。謝謝我的父母,沒有他們辛勤的付出也就沒有我的今天,在這一刻,將最崇高的敬意獻給你們!本文參考了大量的文獻資料,在此,向各學術(shù)界的前輩們致敬!
20
編號
無錫太湖學院
畢業(yè)設計(論文)
相關(guān)資料
題目: 餃子機及傳動系統(tǒng)設計
信機 系 機械工程及自動化專業(yè)
學 號: 0923039
學生姓名: 湯東鵬
指導教師: 戴寧 (職稱:副教授 )
(職稱: )
2013年5月25日
目 錄
一、畢業(yè)設計(論文)開題報告
二、畢業(yè)設計(論文)外文資料翻譯及原文
三、學生“畢業(yè)論文(論文)計劃、進度、檢查及落實表”
四、實習鑒定表
無錫太湖學院
畢業(yè)設計(論文)
開題報告
題目: 餃子機及傳動系統(tǒng)設計
信機 系 機械工程及自動化 專業(yè)
學 號: 0923039
學生姓名: 湯東鵬
指導教師: 戴寧 (職稱:副教授 )
(職稱: )
2012年11月25日
課題來源
自擬題目
科學依據(jù)(包括課題的科學意義;國內(nèi)外研究概況、水平和發(fā)展趨勢;應用前景等)
(1)課題科學意義
餃子食品機械的應用前景和發(fā)展現(xiàn)狀 餃子食品在我國歷史悠久,伴隨著幾千年的文明的發(fā)展已經(jīng)成為我國食品文化中的代表,如餃子、包子、餛沌是主食的一部分;湯圓、月餅、粽子是傳統(tǒng)節(jié)日中必不可缺的食物。如今,經(jīng)濟的迅速增長、人民生活水平的提高和生活節(jié)奏的加快,對食品行業(yè)提出了新的要求。而本人認為這些要求可以歸納為兩大類: 其一是食品的質(zhì)量:如食用口感、衛(wèi)生狀況、營養(yǎng)含量等。 其二便是食品供應的速度。 而解決這兩個矛盾要求的辦法便是實現(xiàn)食品生產(chǎn)的機械化和自動化, 通過機械動作可以極大程度的提高食品的生產(chǎn)率; 采用環(huán)保的機械材料和嚴格的密封技術(shù)可以很好的保證食品衛(wèi)生;而合理的工藝編排更能改善食品的口感。
(2)餃子機的研究狀況及其發(fā)展前景
目前國內(nèi)外廠家在包餡夾餡食品機械化上的研究已經(jīng)取得了一定的成果成功研發(fā)了餃子機、包子機、餛沌機、湯圓機、月餅機以及自動化程度更高的全自動萬能包餡機。 因東西方飲食文化的差異, 目前國外包餡成型類機械主要為日本所生產(chǎn),如日產(chǎn)的自動萬能包餡機,其最大生產(chǎn)能力可達每小時 8000 個,且加工范圍極廣,能生產(chǎn)各式饅頭、包子、餃子、夾餡餅干、壽司、等等近百種產(chǎn)品,采用可拆卸料斗能實現(xiàn)快速更換餡料,內(nèi)置的無級變速調(diào)控裝置可以實現(xiàn)皮和餡的任意配比。廣泛用于各種帶餡食品的加工。 而國內(nèi)相關(guān)機械雖然在自動化和多功能方面較之日本產(chǎn)品還有一定的差距, 但是通過改革開放以后二十余年的發(fā)展亦取得了很大的進步。 以上海滬信飲料食品機械有限公司生產(chǎn)的水餃機為例:配備 1.1Kw 的電動機,生產(chǎn)效率達每小時 7000 個。已相當接近日產(chǎn)餃子機的生產(chǎn)水平。
每逢過時過節(jié)現(xiàn)做現(xiàn)賣餃子往往出現(xiàn)供不應求的現(xiàn)象。當然也有很多人選擇在家里自己做, 卻需要提前半天甚至一天進行準備,而包餃子的時候更是要叫上好幾個親朋過來幫忙方可。 因此如果能研究開發(fā)一種能夠以機械動作代替人工勞動的機器, 那么除了可以節(jié)約大量的時間、降低餃子的生產(chǎn)成本、提高利潤之外,更可以免除人們冬日里冒寒排隊購物之苦,一舉多得。餃子生產(chǎn)機的初步目標確定為能夠?qū)崿F(xiàn)餃子包餡成型工藝的機械化。 未來可在此基礎(chǔ)上加以改進和擴展,以實現(xiàn)橫縱兩方向發(fā)展。即餃子生產(chǎn)全過程的無人干預自動化與多功能化。
研究內(nèi)容
① 熟悉餃子機的工作原理與結(jié)構(gòu);
② 熟悉餃子機傳動系統(tǒng)的布置與結(jié)構(gòu);
③ 熟練掌握傳動系統(tǒng)的設計計算方法;
④ 掌握CAD的使用方法;
⑤ 能夠熟練使用UG進行三維的畫圖設計。
擬采取的研究方法、技術(shù)路線、實驗方案及可行性分析
(1)實驗方案
對餃子機整體設計,擬定其傳動部分的結(jié)構(gòu)、轉(zhuǎn)速等,使其能夠半自動的進行加工。
(2)研究方法
①用CAD進行二維畫圖,對餃子機結(jié)構(gòu)有個全面的了解。
② 對餃子的傳動部分進行計算與結(jié)構(gòu)設計,使其提供合適的動力。
研究計劃及預期成果
研究計劃:
2012年10月12日-2012年12月31日:按照任務書要求查閱論文相關(guān)參考資料,完成畢業(yè)設計開題報告書。
2013年1月1日-2013年1月27日:學習并翻譯一篇與畢業(yè)設計相關(guān)的英文材料。
2013年1月28日-2013年3月3日:畢業(yè)實習。
2013年3月4日-2013年3月31日:餃子機傳動系統(tǒng)計算和總體結(jié)構(gòu)設計。
2013年4月1日-2013年4月14日:傳動箱設計。
2013年4月15日-2013年4月28日:零件圖及三維畫圖設計。
2013年4月29日-2013年5月21日:畢業(yè)論文撰寫和修改工作。
預期成果:
達到預期的畢業(yè)設計要求,設計出的餃子機可以進行半自動加工,可以快速美觀的加工出餃子,并且傳動簡單緊湊、滿足工作要求。
特色或創(chuàng)新之處
① 餃子機可以無需手工進行制作。
② 餃子制作過程安全,方便,快速,可以批量生產(chǎn)。
③ 傳動路線簡單、緊湊,滿足餃子加工的要求。
已具備的條件和尚需解決的問題
① 設計方案思路已經(jīng)明確,已經(jīng)具備機械設計能力和餃子機方面的知識。
② 進行結(jié)構(gòu)設計的能力尚需加強。
指導教師意見
指導教師簽名:
年 月 日
教研室(學科組、研究所)意見
教研室主任簽名:
年 月 日
系意見
主管領(lǐng)導簽名:
年 月 日
英文原文
wear 181-183 (1995) 868-875
Case Study
Theoretical and practical aspects of the wear of vane pumps
Part B. Analysis of wear behaviour in the Vickers vane pump
test
A. Kunz a, R. Gellrich b, G. Beckmann c, E. Broszeit a
a Institute of Material Science, Technical University Darmstadt, P.O. Box 11 1452, 64229 Darmstadt,Gcmb University for Technol08y, Economy and Social Science Zittau/Goditz, Facuky of Maihematics, P.O. Box 264, 02763 Zutau
cPetersiliensrr. 2d, 03044 Cottbus, Received 16 August 1994; accepted l November 1994
Abstract
The wear behaviour of the vane pump used in the standard method for indicating the wear characteristics of hydraulicfluids (ASTM D 2882/DIN 51 389) has been examined by comparison of the calculated wear and experimental data using alubricant without any additives. In addition to the test series according to DIN 51 389, temperature profiles from the pump have been analysed using the bulk temperatures of the contacting components and the temperature in the lubrication gap as input data for the wear calculation. Cartridges used in tests according to the Gennan standard have been examined extensively before and after each run to obtain input data for the mathematical model and to Jocate wear. An analysis of the :tluid properties and an investigation of the innuence of wear particles in the hydraulic circuit were performed. The experimental results were compared with the wear prediction, which was verified by the agreement in terms of load, temporal wear progress and local wear. Conclusions have been drawn with regard to the validity of the load assumptions and wear calculation, as well as to the limits of applicability of this method in the presence of additives.
Keywords: Vane pumps; Hydraulic fluids; Wear prediction; Vickers vane pump test
1. Introduction
Efforts to develop a mathematical tool for wearprediction will not be successful without considering wear and its phenomena. The task of Part B of this study is to describe the analysis of the wear behaviour in the tribo system investigated and how the knowledge achieved influences the calculations. Input data are derived from the measurement of mechanical and geometrical quantities, such as the hardness, stylus profilometry, fluid properties and contact radii. Thermal quantities are also essential for the modelling of lubrication. The calculations must be verified with wear data. Because the tribo system to be analysed is the vane pump employed in the Vickers vane pump test,which has been in use for about 40 years, several wear data can be used for comparison between calculated and measured wear results. These are the wear masses0043-1648/95/$09.50@ 1995 Elsevier Science S.A. All rights reserved SSDI 0043-1648(94)07087-3 after each tcst run, the progrcssion of wear over time and the local wear on the inner ring surface; in combination, these enable a comprehensive statement to be made on the validity of the mathematical model described in Part A.
2. Experiments
AlI Vickers vane pump tests described were run with the same fiuid. It is a reference oil of the German Rcscarch Association for Transmission Technique (FVA), and is a mineral oil without any additives (FVA3). Thus the disturbing influences of additives can be excluded.
2./.Input data for calculation
Fig. 1 lists the input and output quantities of the calculations. Most of the input parameters were derived surface profiles contact force and contact velocity dynamic viscosity contact radiihardness values Youngs moduli, Poisson numbersand lubrication gapspecific shear energy densities* pressure exponentc,f viscosity; tlubrication gap temperature
Rough surfuce ←→ shaar energy hypot ←→ elasto liubiction
↓
Wm=f(t)
Wf =f(ɑ)
Fig. 1. Input parameters and output quantities of the mathematicalmodel of Part A.
Fig. 2. Cartridge V 104 C: bushing, rotor, ring, bushing (abcwe),single vane, pin (below).experimentally from all the components involved beforeand after use in the vane pump tests. The mechanical components, which must be renewed for each test run,are shown in Fig. 2. Such a cartridge kit consists of a rotor, ring, 12 vanes, bushings and pin.
Stylus profilometry was performed on the inner surface of the ring and on the tips of two vanes of the cartridge before and after each test run. Earlier investigations have shown that ten parallel sections in the sliding direction on each body are sufficient to describe the surface topography in a statistically satisfactory manner as a two-dimensionalisotropic gaussianfield according to Ref. [1]. Only the high pass filtered components of the profile (sampling length, 1.5 mm; cut o五 0.25 mm) were used to determine the spectral moments mo, m2, m4 and the parameter of roughness a. According to the partition of the contact force into different loading zones, the topographic data of the new surfaces were used for zone IV (low level load, see Part A). For the other zones with higher contact forces, the profiles of the surfaces in the final condition were used, which corresponds to the appearance of the inner ring surface after the test runs.
The contact force and contact velocity were calculated with different fluid pressures and dynamic forces acting on the vanes, revolution number and ring radu, whereas the change in contact radius was documented with a profile projector. Because the ring radii are much larger thar) the radii of the vanes in the contact zone, the vanes can be assumed to be hertzian cylinders sliding
along a plane surface and the contact radii are simply the radii of the vane tips. Each vane tip was twice drawn up at magnifications of 100 : 1 and the contact radii and contact locations were measured with a stenciLMean values of the contact radii were transferred to the calculation, which is based (similar to the surfaceprofiles) on vanes in both conditions.
The Vickers hardness HVlO was measured on thering and three vanes of each cartridge. This hardnessleads to a better reproducibility than microhardness values, but due to the large indenter load, it couldonly be taken after the test runs. Therefore changes in hardness values could not be registered.
The Young's moduli, Poisson numbers and densities of the ring (AISI 52100) and vane materials (M2 reg C) are the first input parameters in the shear energy hypothesis and were obtained from the literature. The specific shear energy densities (see Part A) are materialspecific constants [2l.
The fluid properties (Fig. 1) were measured, derived from the literature or calculated. To obtain the dynamicviscosity, the densities and kinematic viscosities at 20,40 and 80 0C were measured. Because the fluid is a reference oil of FVA, the pressure exponent of the viscosity is given [3]. The temperature in the lubrication gap between the ring and vanes was approx:imated by measurements and calculations described below.
2.2. Temperature profiles
Temperature measurement was performed to obtain information on how a heatable tribometer must be controlled to simulate the wear behaviour of the vane pump. Therefore shortened test runs were carried out until temperatures were stabilized. These 10 h vane pump tests delivered the input data for the approximation of the lubrication gap temperature in the ring-vane contact, as well as additional wear masses to be compared with the calculated progressiort of wear in time. The sampling principles for acquiring the temperature profiles of the vane pump are illustrated in Fig. 3.
The temperature of the lubricant in the gap between the ring and vanes was estimated to be equal to or greater than the bulk temperature on the inner ring surface. Following the first main statement of thermodynamics, the heat flux Q mp into the components of the pump can be derived from with the fluid as the medium for energy transport.Qa,mp can only be transferred to the components shownin Fig. 2. For the same temperature differences and materials, this heat nUX can be divided into single component fluxes ac cording to the relation of masses. The derived flux Qring is the heat which flows in a certain time period in a radial direction through the ring. With the known temperatures on the outer ring surface, the bulk temperatures on the inner ring surface
can be calculated and transferred to the model of elastohydrodynamic lubrication.
All test runs with the Vickers vane pump V 104 C were performed on a test rig according to ASTM D2882/DIN 51 389, which is shown schematically in Fig.
4. These standards describe the procedure for testingthe anti-wear properties of hydraulic fiuids. To start the Vickers vane pump test according to the German standard, the system pressure must be raised in steps of 2 MPa every 10 min, beginning at 2 MPa, until a final pressure of 14 MPa is reached. At this stage, the fluid temperature measurcd bcfore the pump (see Fig.4) must be controlled to guarantee a kinematic viscosity of 13 mm2 S-i at the inlet for every :tluid tested. These conditions must be maintained until the test is aborted normally after 250 h by opening the bypass of the pressure control valve before the motor is stopped. By a comparison of the wear achieved on the ring and vanes with the upper wear limits, the anti-wear properties of the fluid tested can be derived.
For performing the tests safely with the fluid FVA3, it was preheated t0 40 0C and circulated in a pressurefree way. The damage which may occur during the critical first hour of the runs can be avoided using TiNcoated bushings [4]. For comparison with the results derived from computation, the wear produced in these runs must be documented as amounts, both locally and temporally.
The wear masses were derived from the weight differences of the ring and vanes before and after each run. They were obtained from a sequence of four 250 h test runs and tw0 10 h runs for temperature measurement. The local linear amount of wear was documented by the differences in the inner ring radii perdegree of revolution, which were measured by surface digitization along the inner ring surface at three different positions of the ring width before and after the tesi runs.
In earlier investigations [5], the wear progression over time of the vanes was measured under identical testing conditions, except for a lower fluid temperature. For this experiment, the radiotracer technique was used. Two vane tips in the set of 12 vanes of each cartridge were radiologically activated by bombardment with protons. A detector close to the pump body allowed thedecrease in radiological activity to be monitored continuously, which was found to be reciprocally proportional to the linear amount of vane wear as a function of time [5l. Due to the good tempering properties of the vane material (M2 reg C), with a specific secondary hardness maximum between 450 and 550 0C, the infiuence of the activation process at 220 0C on the wear
behaviour of the activated zone of the vane tips could be excluded.
Phyd+Pfric-Qcomp-Qfluid=0 (1)
Qfluid=mcfluid△Tfluid (2)
Fig. 4. Hydraulic circuit of the test rig.
3 result
lines the statistical reliability of surface modelling as a two-dimensional isotropic gaussian field. Although only the filtered profiles scanned in the sliding direction are shown, a distinct change in surface roughness is obvious. A good representation of the wear phenomena (see Part A) by the input data for the wear calculation derived from these profiles can be assumed.
The change in the vane tip shape over the testing period is documented in Part A. The hardness values for the rings and vanes varied from 743 t0 769 HVlO (rings) and from 778 t0 816 HVlO (vanes). In all cases, the vanes of one cartridge had higher hardness values than the ring, but these differences varied and had a large influence on the wear calculation (see Part A).
The measurement of the fiuid properties led, in combination with the kinematic viscosity prescribed by the German standard, to a fluid temperature of 84-86oC at the pump inlet. Together with the other temperature measurements acquired in the 10 h runs, these temperature profiles are illustrated in Fig. 6.
Test Number t was found that, in about l h, all temperatures were stabilized. It should be noted that all temperatures in or on the pump components are higher than the fluid temperature measured behind the pump. The highest temperatures were found on the outer ring surface,
with significant differences depending on the location of the thermocouples.
The calculation of the bulk temperatures on the inner ring surface via the heat flux balance eliminated the infiuence of the different ring thicknesses at the scan locations. Depending on tbese different distances for heat conduction, between 4 and 7 0C must be added to the mean values of the component temperatures to obtain the surface temperatures. These values are 20c70 higher than the fluid temperature measured behind the pump, which was used as input data for the wear
calculation.
During the l h starting phase of the test runs, the stepwise increase in system pressure leads to an immediate effect on the component temperatures, whereas the fluid temperature increases with a more or less constant gradient, which demonstrates the association of load and frictional heat.
The four 250 h test runs caused a mixture of adhesive and abrasive wear at a high level (see Part A). The wear results achieved are shown in Fig. 7. Ring wear increased from test I to test 3. Therefore the 12 pm filter normally used was replaced after the third test by a 3 pm filter, and a pressure-free run with an additional cartridge was started as a cleaning procedure. Due to the filter change, the reservoir needed to be refilled by about lOv-/o of its content with fresh fluid before control test 4, again with a 12 ym filter, was started. In addition to these efforts to minimize possible wear particle influence, a comparison of the viscosity and neutralization number with those of fresh fluid showed only an insignificant rise in viscosity and a low neutralization number after 750 h of testing. In test 4, the highest value for ring and vane wear at a constant level was achieved. For all tests, the linear amount of wear on the ring surface showed a strong dependence
on the measurement location with strictly limited areas of high and low wear.
The results of continuous vane wear monitoring are shown in Fig. 8 in addition to the principle of measurement. Degressive wear laps were found, where the stationary level was reached after 100 h.
4. Discussion
Before the wear calculations can be verified by wear data, it must be demonstrated that the assumptions,measurements and calculations forming the input for the mathematical model correlate with the wear measured.Fig. 9 compares the calculated load n the ring-vane contact, derived from the contact force and changing shapes of the vane tips introduced in Part A, with the measured linear amounts of wear along the inner ring surface and the temperature distribution at the same place. There is qualitatively good correlation for the progression of load and wear with characteristic leaps at almost the same degree of revolution. In addition, high temperature, resisting dynamic equilibrium, is found where the load and wear are high and vice versa. Therefore it is absolutely correct to create different loading zones (according to fig. 2 in Part A) as input for the wear calculations. Although a few differences in quality can be found in the pro-
gression of hertzian pressure and the linear amounts of wear, serious mistakes in the collection of input information are probably avoided, so that the verification of the calculated wear results by experimental data will show the validity of the mathematical model.
For local amounts of linear ring wear, this verification can be seen in Fig. 10. It should be noted that the calculation and experimental results are placed in the same decade, the progressions show the characteristic leaps similar to the load in Fig. 9 at almost the same degrees and the amounts are directly comparable. The loading zones are adapted to the progression of the contact force (see Part A), which the calculated linear wear must follow as well as the hertzian pressure. The
different shapes of the two graphs between 300 and 700 (2100 and 2500) turn angles remain unsatisfactory, because this shows an uncertainty in the load as sumptions. The fluid pressure in a cell formed by two vanes, rotor and ring was assumed to be segmentally constant. Therefore the contact force was determined to follow these assumptions, which need to be dempressure) in the ring-vane contact, derived from the contact force and changing shapes of the vane tips introduced in Part A, with the measured linear amounts of wear along the i
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