常規(guī)式游梁抽油機(jī)設(shè)計(jì)【三維SW圖】【含7張CAD圖紙+文檔全套】
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前言
目前,采油方式有自噴采油法和機(jī)械采油法。在機(jī)械采油法中,有桿抽油系統(tǒng)是國(guó)內(nèi)外油田最主要的,也是至今一直在機(jī)械采油方式中占絕對(duì)主導(dǎo)地位的人工舉升方式。有桿抽油系統(tǒng)主要由抽油機(jī)、抽油桿、抽油泵等三部分組成,抽油機(jī)是有桿抽油系統(tǒng)最主要的升舉設(shè)備。根據(jù)是否具有游梁,抽油機(jī)可以劃分為游梁式抽油機(jī)和無(wú)游梁式抽油機(jī)。而常規(guī)游梁抽油機(jī)自誕生以來(lái),歷經(jīng)百年使用,經(jīng)歷了各種工況和各種地域油田生產(chǎn)的考驗(yàn),經(jīng)久不衰。目前仍在國(guó)內(nèi)外普通使用。常規(guī)游梁式抽油機(jī)以其結(jié)構(gòu)簡(jiǎn)單、耐用、操作簡(jiǎn)便、維護(hù)費(fèi)用低等明顯優(yōu)勢(shì),而區(qū)別于其他眾多拍油機(jī)類(lèi)型,一直占據(jù)著有桿系采油地面設(shè)備的主導(dǎo)地位。
游梁式抽油機(jī)的主體結(jié)構(gòu)為曲柄搖桿機(jī)構(gòu)。根據(jù)驢頭和曲柄搖桿機(jī)構(gòu)相對(duì)于支架的位置,游梁式抽油機(jī)的機(jī)構(gòu)形式可以劃分為常規(guī)型和前置式兩種;根據(jù)平衡方式的不同,游梁式抽油機(jī)可以劃分為曲柄平衡、游梁平衡和復(fù)合平衡。
常規(guī)型游梁式抽油機(jī)主要由發(fā)動(dòng)機(jī)、三角皮帶、曲柄、連桿、橫梁、游梁、驢頭、懸繩器、支架、撬座、制動(dòng)系統(tǒng)及平衡重等組成。
發(fā)動(dòng)機(jī)安裝在撬座上,其安裝位置有兩種,一種是將發(fā)動(dòng)機(jī)置于整體尾部,另一種是將發(fā)動(dòng)機(jī)放在支架下面。
減速箱為二級(jí)齒輪傳動(dòng)減速箱,傳動(dòng)比為30左右.齒輪型式一般小功率用斜齒,大功率用人字齒。近年來(lái)推廣使用點(diǎn)嚙合雙圓弧人字齒。
曲柄一端與減速器輸出軸固結(jié),另一端與連桿鉸接.
連桿與橫梁常見(jiàn)有兩種型式:小型抽油機(jī)多為組焊結(jié)構(gòu),靠改變后臂長(zhǎng)度來(lái)調(diào)節(jié)沖程.大型抽油機(jī)多為整體機(jī)構(gòu),靠改變曲柄與連桿鉸接位置來(lái)調(diào)爺沖程。
游梁由型鋼組焊而成,也有用大型工字鋼整體制造。
驢頭由鋼板組焊而成,有上翻式、側(cè)轉(zhuǎn)式、拆繼式幾種形式。
平衡重為金屬塊。小型抽油機(jī)多裝于游梁尾部,大型抽油機(jī)多裝于曲柄兩翼.平衡重可根據(jù)需要而調(diào)整。
本設(shè)計(jì)將對(duì)常規(guī)游梁式抽油機(jī)進(jìn)行設(shè)計(jì)與計(jì)算,以達(dá)到對(duì)常規(guī)游梁式抽油機(jī)的優(yōu)化設(shè)計(jì)的目的。
目錄
1設(shè)計(jì)任務(wù)書(shū) 1
1.1課題內(nèi)容 1
1.2設(shè)計(jì)內(nèi)容: 1
2總體方案的設(shè)計(jì) 2
2.1抽油機(jī)設(shè)計(jì)原理的確定 2
2.2桿長(zhǎng)尺寸的設(shè)計(jì)計(jì)算 3
2.4安裝尺寸與機(jī)構(gòu)相關(guān)參數(shù) 3
2.5常規(guī)游梁式抽油機(jī)零部件關(guān)系 3
3游梁抽油機(jī)基本參數(shù)的確定 4
3.1游梁抽油機(jī)的運(yùn)動(dòng)分析 4
3.2游梁式抽油機(jī)懸點(diǎn)載荷計(jì)算 7
3.3游梁式抽油機(jī)減速箱曲柄軸扭矩計(jì)算 10
3.4游梁抽油機(jī)的抽汲工況 12
3.5游梁式抽油機(jī)的電動(dòng)機(jī)選擇計(jì)算 13
4常規(guī)游梁是抽油機(jī)的平衡計(jì)算 14
5變速機(jī)構(gòu)的傳動(dòng)比分配及其結(jié)構(gòu)確定 14
5.1變速機(jī)構(gòu)的傳動(dòng)比分配 14
6主要部件的設(shè)計(jì) 15
6.1曲柄 15
6.2游梁 16
6.3驢頭 17
6.4橫梁 18
6.5常規(guī)游梁抽油機(jī)裝配體 18
參考文獻(xiàn) 19
致謝 20
1設(shè)計(jì)任務(wù)書(shū)
1.1課題內(nèi)容
(1)主要參數(shù):型號(hào):CYJ3—2.1—13HB
(2)最大載荷:30KN
(3)沖程長(zhǎng)度: 1.4,1.7,2.1(單位:m)
(4)沖程次數(shù):6,9,12 (單位:)
1.2設(shè)計(jì)內(nèi)容:
(1)總體方案設(shè)計(jì)(總體尺寸,四桿機(jī)構(gòu));
(2)運(yùn)動(dòng)分析(計(jì)算位移、速度、加速度);
(3)動(dòng)力分析及平衡計(jì)算;
(4)主要部件結(jié)構(gòu)設(shè)計(jì)、計(jì)算;
(5)電機(jī)選擇與油井匹配參數(shù)的確定;
2總體方案的設(shè)計(jì)
2.1抽油機(jī)設(shè)計(jì)原理的確定
目前,常規(guī)式游梁抽油機(jī)采用的是四桿機(jī)構(gòu)原理。國(guó)內(nèi)外使用的游梁式抽油機(jī)四桿機(jī)構(gòu)的循環(huán)主要有一下三種:對(duì)稱(chēng)循環(huán)、近似對(duì)稱(chēng)循環(huán)和非對(duì)稱(chēng)循環(huán)。在此我們采用近似對(duì)稱(chēng)循環(huán)四桿機(jī)構(gòu)。
圖2-1游梁式抽油機(jī)四桿機(jī)構(gòu)原理圖
近似對(duì)稱(chēng)循環(huán)四桿機(jī)構(gòu)主要參數(shù)參考范圍:
(1)傳動(dòng)角 : 最大傳動(dòng)角和最小近似對(duì)稱(chēng)于,故 ,。
(2)極位夾角:
(3)游梁最大擺角:
(4)基桿傾斜角:可取 H-G=
(5)
(6)懸點(diǎn)下死點(diǎn)時(shí)曲柄初始角:
(7)各桿長(zhǎng)之間相對(duì)時(shí)間限制:,, , ,若,可取,若 。
2.2桿長(zhǎng)尺寸的設(shè)計(jì)計(jì)算
由于最大沖程,所以各個(gè)桿長(zhǎng)之間存在以下關(guān)系:
由于本設(shè)計(jì)的最大沖程,所以,在此取并且取,則其他桿長(zhǎng)為:
此外,
式中:R——曲柄半徑,m;
——游梁后臂長(zhǎng)度,m;
——游梁前臂長(zhǎng)度,m;
——連桿長(zhǎng)度,m;
J——基桿長(zhǎng)度(從曲柄旋轉(zhuǎn)中心到游梁支點(diǎn)的距離)m;
2.3平衡方式的確定
目前,國(guó)內(nèi)外采用的機(jī)械平衡方式主要有:曲柄平衡、游梁平衡和復(fù)合平衡。由于本抽油機(jī)是短沖程、變沖次的工況要求,所以采用曲柄平衡。而曲柄平衡較游梁平衡來(lái)說(shuō),調(diào)整更加方便。
2.4安裝尺寸與機(jī)構(gòu)相關(guān)參數(shù)
(1)游梁支撐到底座的高度3~6m
(2)執(zhí)行機(jī)構(gòu)的行程速度比系數(shù)1.2
(3)減速器輸出軸中心到底座的高度0.6m
(4)曲柄半徑:0.5~1.2m
2.5常規(guī)游梁式抽油機(jī)零部件關(guān)系
常規(guī)游梁式抽油機(jī)零部件關(guān)系框圖如圖2-2:
圖2-2常規(guī)游梁式抽油機(jī)零部件關(guān)系框圖
3游梁抽油機(jī)基本參數(shù)的確定
3.1游梁抽油機(jī)的運(yùn)動(dòng)分析
將四桿機(jī)構(gòu)簡(jiǎn)化為曲柄滑塊機(jī)構(gòu)時(shí),作懸點(diǎn)的運(yùn)動(dòng)規(guī)律計(jì)算。其簡(jiǎn)化圖如下
圖3-1 懸點(diǎn)的運(yùn)動(dòng)規(guī)律簡(jiǎn)化圖
當(dāng)時(shí),游梁與連桿的連接點(diǎn)處于上死點(diǎn),相對(duì)應(yīng)的懸點(diǎn)C處于下死點(diǎn);當(dāng)時(shí),B處于上死點(diǎn),相對(duì)應(yīng)的懸點(diǎn)C處于上死點(diǎn)
B點(diǎn)的沖程長(zhǎng)度
取B點(diǎn)的位移零點(diǎn),向下為位移的正方向,則任意曲柄轉(zhuǎn)角時(shí)B點(diǎn)的位移為: 由三角形OAD可得:
所以,
按二項(xiàng)式定理展開(kāi)
B點(diǎn)位移 S
為了確定懸點(diǎn)最大加速度,可對(duì)對(duì)求導(dǎo),并令其等于零,求得取得極值時(shí)的角及對(duì)應(yīng)的及加速度值
當(dāng),上面方程二無(wú)解,在此情況下,按方程一可得加速度極值在處,即上,下死點(diǎn)處。
當(dāng)懸點(diǎn)在也取得極值,對(duì)此不再討論。
3.2游梁式抽油機(jī)懸點(diǎn)載荷計(jì)算
(一)懸點(diǎn)靜載荷的計(jì)算
在此,我們對(duì)上死點(diǎn)、下死點(diǎn)、上沖程和下沖程四種情況進(jìn)行計(jì)算。
(1)上沖程
在此過(guò)程中,游動(dòng)閥在柱塞上部油柱壓力的作用下關(guān)閉,而固定閥在柱塞下面泵筒內(nèi)、外壓力差作用下打開(kāi)。由于游動(dòng)閥關(guān)閉,使得懸點(diǎn)承受抽油桿自重和柱塞上油柱重,這兩個(gè)載荷方向都是向下。同時(shí),因?yàn)楣潭ㄩy打開(kāi),使得油管外一定沉沒(méi)度的油柱對(duì)柱塞下表面產(chǎn)生方向向上的壓力。所以,此過(guò)程中,懸點(diǎn)靜載荷等于:
——抽油桿材料的密度,kg/m;
——原油的密度, kg/m;
A——抽油桿橫截面面積, m;
A——泵柱塞橫截面面積, m;
L——抽油桿長(zhǎng)度或下泵深度,m;
h——泵的沉沒(méi)度, m;
——油井中動(dòng)液面以上(即L-L段液柱),斷面積等于柱塞面積的油柱重,N.
(2)下沖程
游動(dòng)閥由于柱塞上下壓力差而打開(kāi),而固定閥在泵筒內(nèi)外壓力差作用下關(guān)閉。游動(dòng)閥打開(kāi),使懸點(diǎn)只承受抽油桿柱在有中重力。固定閥關(guān)閉,使得油柱重力移到固定閥和油管上。此時(shí),其靜載荷為
(3)下死點(diǎn)
這時(shí),油桿和連桿的載荷都發(fā)生了變化。
油桿在這一瞬間,其載荷發(fā)生了變化,變化量,載荷增減,使得抽油桿拉長(zhǎng),其伸長(zhǎng)量等于:
E——鋼材的彈性模量,
油管在這一瞬時(shí)載荷也發(fā)生了變化,使得油管縮短,其油管柱縮短量等于:
——油管管壁的橫截面積
這樣一來(lái),雖然懸點(diǎn)帶著柱塞一起往上移動(dòng),但是由于油管柱的縮短,使油管柱的下端也跟著柱塞往上移動(dòng),柱塞對(duì)泵筒還是沒(méi)有相對(duì)運(yùn)動(dòng),即還不能抽油,一直到懸點(diǎn)經(jīng)過(guò)一段距離等于以后,柱塞才開(kāi)始抽油。
經(jīng)過(guò)上述分析,懸點(diǎn)從下死點(diǎn)到上死點(diǎn)雖然走過(guò)了沖程長(zhǎng)度S,但是因抽油桿柱和油管柱的靜力變形結(jié)果,使得抽油泵柱塞的有效沖程長(zhǎng)度要比S小,所以
靜變形的大小等于:
稱(chēng)為變形分配系數(shù),一般可取0.6~0.9。
(4)上死點(diǎn)
上死點(diǎn)的情況恰與下死點(diǎn)相反。在此不做深入計(jì)算。
經(jīng)過(guò)分析計(jì)算,在上、下沖程內(nèi),懸點(diǎn)靜載荷隨著懸點(diǎn)位移的變化規(guī)律是一個(gè)平行四邊形ABCD。
圖3-2 靜力示功圖
(二)懸點(diǎn)動(dòng)載荷的大小和變化規(guī)律
在井較深,抽油機(jī)沖數(shù)較大的情況下,必須考慮動(dòng)載荷的影響,動(dòng)載荷是由慣性載荷和振動(dòng)載荷兩部分組成的。
(1)慣性載荷
慣性載荷包括抽油桿和油柱兩部分,即F和F,如果略去抽油桿柱和油柱的彈性影響,可以認(rèn)為,抽油桿柱以及油柱各點(diǎn)的運(yùn)動(dòng)規(guī)律和懸點(diǎn)完全一致,所以F和F的大小和懸點(diǎn)加速度a大小成正比,而作用方向和后者相反。
F=
F=
——考慮油管過(guò)流斷面擴(kuò)大引起油柱加速度降低的系數(shù)
(1)慣性載荷對(duì)懸點(diǎn)總載荷的影響
上沖程時(shí),柱塞(或抽油桿)帶著油桿運(yùn)動(dòng),所以上沖程的慣性載荷F為:
F=F
m——表示油柱慣性載荷與抽油桿柱慣載荷的比值,利用式可得
m=
(三)懸點(diǎn)的最大載荷和最小載荷
懸點(diǎn)的最大載荷F和最小載荷F,特別是最大載荷F,特別是最大載荷F是正確設(shè)計(jì)和選擇抽油機(jī)和抽油桿以及確定電動(dòng)機(jī)功率的主要依據(jù)之一。
3.3游梁式抽油機(jī)減速箱曲柄軸扭矩計(jì)算
對(duì)計(jì)算時(shí)采用的符號(hào)作如下解釋
F——懸點(diǎn)載荷,N;
——曲柄平衡塊重力,N;
——曲柄平衡塊到曲柄旋轉(zhuǎn)中心的距離,m;
——曲柄自重,N;
——曲柄重心到曲柄旋轉(zhuǎn)中心的距離,m;
——連桿所受的拉力,N;
T——連桿力在曲柄切像上的分力,沿曲柄旋轉(zhuǎn)的方向?yàn)檎?,m;
M——減速箱曲柄軸輸出扭矩,沿曲柄旋轉(zhuǎn)方向?yàn)檎?,N.m.
為了便于分析,將曲柄平衡塊重力及曲柄自重折算至曲柄銷(xiāo)處,這種折算要保證折算前后對(duì)曲柄旋轉(zhuǎn)中心的力矩不變,折算后的等效載荷用來(lái)表示。
首先取游梁為研究對(duì)象,將諸力對(duì)游梁旋轉(zhuǎn)中心取力矩可得連桿力為:
則連桿力在曲柄切向上的分力T為;
取曲柄為研究對(duì)象,為提升油井內(nèi)的抽油桿柱和油柱,減速箱曲柄軸輸出扭矩M,曲柄平衡塊重力與曲柄自重的等效載荷所產(chǎn)生的扭矩共同克服切向力T所產(chǎn)生的扭矩,由曲柄平衡條件;Rsin(2
M=
=
上式中的第一項(xiàng)表示是懸點(diǎn)載荷F在曲柄上所產(chǎn)生的扭矩,稱(chēng)為油井負(fù)荷扭矩;
式中的只取決于抽油機(jī)的幾何尺寸和曲柄轉(zhuǎn)角,其意義為單位懸點(diǎn)載荷在曲柄上所產(chǎn)生的扭矩,將其稱(chēng)之為扭矩因數(shù),用表示;
式中的為曲柄自重及曲柄平衡重在曲柄軸上所產(chǎn)生的扭矩,稱(chēng)之為曲柄平衡扭轉(zhuǎn),用表示;
式中——曲柄最大平衡處扭矩,即曲柄處于水平位置()時(shí)曲柄自重及曲柄平衡重對(duì)曲柄軸所產(chǎn)生的扭矩。
B為抽油機(jī)的結(jié)構(gòu)不平衡重,其值等于連桿與曲柄銷(xiāo)脫開(kāi)時(shí),為了保持游梁處于水平位置而需要加在光桿上的力。此力向下時(shí)B取正值,向上時(shí)取負(fù)值。B值可以實(shí)測(cè),也可以根據(jù)抽油機(jī)部件的重力計(jì)算。
對(duì)曲柄平衡抽油機(jī)可得如下公式;
扭矩因數(shù);
最大扭矩我們可以用勒瑪柴諾夫經(jīng)驗(yàn)公式計(jì)算
S——懸點(diǎn)的沖程長(zhǎng)度,m;
——曲柄的最大扭矩,N.m;
——懸點(diǎn)的最大載荷,N;
——懸點(diǎn)的最小載荷,N;
3.4游梁抽油機(jī)的抽汲工況
目前,國(guó)內(nèi)外游梁式抽油機(jī)的抽汲工況主要分為五種:正常的、長(zhǎng)沖程、短沖程、高沖數(shù)的、低沖數(shù)的,五種工況的沖程長(zhǎng)度和沖數(shù)的極值見(jiàn)表
表3-1沖程長(zhǎng)度和沖數(shù)的極值
抽汲工況
沖程長(zhǎng)度
沖程次數(shù)
最大值
最小值
最大值
最小值
正常
1.2
2.4
5
15
長(zhǎng)沖程
2.7
6.0
5
15
短沖程
0.3
1.2
5
15
高沖次
0.9
2.4
15
25
底沖次
0.3
1.5
2
5
在我國(guó)油田上絕大多數(shù)都采用正常的抽汲工況,但在我國(guó)東部主要油田都處于油田開(kāi)發(fā)中后期,油田含水量上升,因此目前長(zhǎng)沖程抽汲工況增加,所以目前國(guó)內(nèi)外抽油機(jī)采用的正常抽汲工況和短沖程抽汲工況還能夠滿(mǎn)足不同抽油井的實(shí)際要求。綜上所述,我們?cè)诖舜卧O(shè)計(jì)中還是以正常的為依據(jù)。
3.5游梁式抽油機(jī)的電動(dòng)機(jī)選擇計(jì)算
游梁式抽油機(jī)裝置的特點(diǎn)
(1) 負(fù)荷是脈動(dòng)的,而且變化大;
(2) 啟動(dòng)困難,要求有大的啟動(dòng)轉(zhuǎn)矩;
(3) 所用的電動(dòng)機(jī)功率不太大,一般不超過(guò)40kW,小的只有幾千瓦,但總的數(shù)量大;
(4) 在露天工作,要求電動(dòng)機(jī)維護(hù)簡(jiǎn)單、工作可靠。
結(jié)合工作特點(diǎn)及工況,在此選擇Y系列的三相異步封閉式鼠籠型電動(dòng)機(jī)。
電動(dòng)機(jī)額定功率的確定:
電動(dòng)機(jī)功率與傳遞到減速箱從動(dòng)軸(曲柄軸)上扭矩關(guān)系式為:
式中M——傳到曲柄軸上的扭矩,N*m;
——電動(dòng)機(jī)的額定功率,kW;
n——曲柄軸轉(zhuǎn)數(shù)(懸點(diǎn)沖數(shù));
——傳動(dòng)效率;
——皮帶傳動(dòng)效率;
——減速箱傳動(dòng)效率。
則電動(dòng)機(jī)額定功率計(jì)算公式為:
然而,一般抽油機(jī)電動(dòng)機(jī)按此表選用:
表3-2一般抽油機(jī)電動(dòng)機(jī)選用表
根據(jù)上表,將電動(dòng)機(jī)的額定功率范圍確定在=5.5~7.5kW。
電動(dòng)機(jī)轉(zhuǎn)速的確定
一般抽油機(jī)選用的減速箱傳動(dòng)比為,帶傳動(dòng)的傳動(dòng)比為,一般。這是抽油機(jī)沖數(shù)按最大沖數(shù)12r/min計(jì)算。則電動(dòng)機(jī)的轉(zhuǎn)速為:
我們?cè)谶@選用Y132M-4
4常規(guī)游梁是抽油機(jī)的平衡計(jì)算
下沖程時(shí),驢頭懸點(diǎn)向下走完沖程長(zhǎng)度S,游梁的后臂提高,把能力儲(chǔ)存起來(lái)。
游梁部件自重抬高的距離為,儲(chǔ)存能量為,曲柄平衡重抬高的距離為,儲(chǔ)存的能量為,曲柄自重抬高的距離為,儲(chǔ)存的能量為。所以平衡裝置儲(chǔ)存能量Q為
5變速機(jī)構(gòu)的傳動(dòng)比分配及其結(jié)構(gòu)確定
5.1變速機(jī)構(gòu)的傳動(dòng)比分配
電動(dòng)機(jī)型號(hào)Y160L-8,其功率為P=7.5轉(zhuǎn)速為N=720則電動(dòng)機(jī)輸出扭矩.
=99.4796
減速箱參數(shù)
,主動(dòng)齒輪軸齒數(shù)
.斜齒輪齒數(shù)
,中間齒輪軸齒數(shù)
,人字齒輪齒數(shù)
,電動(dòng)機(jī)皮帶輪
,電動(dòng)機(jī)皮帶輪
,電動(dòng)機(jī)皮帶輪
,減速器大皮帶輪
減速器比:29.75
皮帶輪速比(電動(dòng)機(jī)配有三個(gè)皮帶輪,減速器主動(dòng)軸上裝有一個(gè)大皮帶輪,故有三種速比)
抽油機(jī)的總速比
在每一種速比下,減速箱被動(dòng)輸出扭矩。
計(jì)算結(jié)果表明,其最大值輸出扭矩低于26kN.m。因此,在設(shè)計(jì)該機(jī)時(shí),選用Y132M-4電動(dòng)機(jī),計(jì)算結(jié)果其最大輸出扭矩
該機(jī)的沖次分別為:
6主要部件的設(shè)計(jì)
6.1曲柄
曲柄是傳遞減速器輸出扭矩的主要部件,所以它必須具有一定的強(qiáng)度和傳動(dòng)可靠性。曲柄一般可用灰鑄鐵、球墨鑄鐵和鑄鋼制成。在曲柄平衡的抽油機(jī)上,兩件曲柄共同承受的抽油機(jī)的全部載荷,因此要求曲柄有很高的承載能力,同時(shí)為了調(diào)整方便和安全,曲柄上沒(méi)有導(dǎo)軌、擋塊、刻度線(xiàn),可以根據(jù)抽油機(jī)工作條件調(diào)整平衡塊位置,使抽油機(jī)保持平衡。擋塊可在緊固的情況下,防止平衡塊不致落下而發(fā)生事故。 此次,在一系列要求下,用QT700-2制成大尺寸常規(guī)普通型曲柄。如圖6-1.
6.1連桿
每臺(tái)抽油機(jī)有兩根連桿,它是傳遞力矩的主要受力桿件,其主件可用管材,也可用其他型材如工字鋼、槽鋼等。但一般多用厚壁無(wú)縫鋼管制成,在無(wú)縫鋼管的兩管端沒(méi)有上、下接頭,上、下接頭通過(guò)焊接與無(wú)縫鋼管連接在一起。上接頭通過(guò)連接銷(xiāo)與橫梁連接在一起,下接頭通過(guò)兩個(gè)螺栓與軸承盒連接在一起,從而完成力矩的傳遞。因此,對(duì)于上下接頭與鋼管的焊縫是否能達(dá)到規(guī)定的強(qiáng)度而滿(mǎn)足使用要求就顯得尤為重要。如果兩根連桿中有一根連桿失效,抽油機(jī)變成單臂傳動(dòng),很有可能被拉翻,造成嚴(yán)重的生產(chǎn)安全事故。焊縫作為整個(gè)連桿的薄弱環(huán)節(jié),都會(huì)引起設(shè)計(jì)人員高度重視,一般在設(shè)計(jì)中對(duì)焊縫的形式,焊接工藝條件,要求以及檢驗(yàn)方法和標(biāo)準(zhǔn)都提出較高的要求和明確的規(guī)定。同時(shí)為了保證兩側(cè)連桿傳動(dòng)平穩(wěn)和傳遞力矩的均衡一致,兩連桿的工作長(zhǎng)度必須完全一致,即達(dá)到一定的尺寸公差要求,這一要求通常用專(zhuān)用工藝裝備來(lái)保證。
所以,選用直徑為80的熱軋圓鋼為主件,而上下接頭均用QT700-2鑄成。如圖6-2
圖6-1曲柄
圖6-2連桿
6.2游梁
游梁是抽油機(jī)的主要承載部件,承擔(dān)著抽油機(jī)的全部工作載荷,因此必須要有足夠的強(qiáng)度和一定的剛度。
選用工字鋼為主要部件,經(jīng)過(guò)鋼板加強(qiáng)后制成。其工字鋼選材為。見(jiàn)圖6-3
6.3驢頭
驢頭用來(lái)將游梁前端的往復(fù)圓弧運(yùn)動(dòng)變?yōu)槌橛蜅U的垂直直線(xiàn)往復(fù)運(yùn)動(dòng),驢頭的圓弧半徑R應(yīng)等于前臂長(zhǎng)度,為了保證在一定沖程長(zhǎng)度下,將圓弧運(yùn)動(dòng)變?yōu)閼尹c(diǎn)的直線(xiàn)運(yùn)動(dòng),驢頭的圓弧面長(zhǎng)度應(yīng)為:
為驢頭懸點(diǎn)的最大沖程。驢頭采用腹板式結(jié)構(gòu)焊接而成,并應(yīng)用側(cè)翻讓位結(jié)構(gòu)進(jìn)行整修時(shí)的讓位。詳見(jiàn)圖6-4。
圖6-3游梁
圖6-4驢頭
6.4橫梁
橫梁用HT200鑄造而成,詳見(jiàn)圖6-5
圖6-5橫梁
6.5常規(guī)游梁抽油機(jī)裝配體
參考文獻(xiàn)
[1] 楊永昌、職黎光、賈逢軍,等. 游梁式抽油機(jī)全臺(tái)效率測(cè)試研究[J]. 石油礦場(chǎng)機(jī)械,1996,25(5):2-5.
[2] 龍以寧. 游梁式抽油機(jī)曲柄銷(xiāo)可靠性討論[J]. 石油礦場(chǎng)機(jī)械,1992,21(5):6-10.
[3] 龐艷華、劉福剛、楊孝君,等. 游梁式抽油用電動(dòng)機(jī)的節(jié)電措施[J].石油礦場(chǎng)機(jī)械 .2004,33(197):79-81.
[4] 張學(xué)魯、季祥云、羅仁全,等.游梁式抽油機(jī)的技術(shù)與運(yùn)用.北京:石油工業(yè)出版社.2001年4月.
[5] 韓成才. 石油鉆采設(shè)備[M].西安:陜西科學(xué)技術(shù)出版社.1999年.
[6] 鄔亦炯、劉卓均,等. 抽油機(jī)[M]. 北京:石油工業(yè)出版社,1994.
[7]梁宏寶、伊蓮娜、孫旭東。游梁式抽油機(jī)節(jié)能技術(shù)改造綜述[J]黑龍江 東北石油大學(xué) 2011年2月
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12 屆畢業(yè)設(shè)計(jì)
常規(guī)式游梁抽油機(jī)
設(shè)計(jì)說(shuō)明書(shū)
學(xué)生姓名 李 軍 斌
學(xué) 號(hào) 8011208117
所屬學(xué)院 機(jī)械電氣化工程學(xué)院
專(zhuān) 業(yè) 機(jī)械設(shè)計(jì)制造及其自動(dòng)化
班 級(jí) 機(jī)械12-1
指導(dǎo)教師 廖結(jié)安
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塔里木大學(xué)教務(wù)處制
常規(guī)游梁式抽油機(jī)設(shè)計(jì)常規(guī)游梁式抽油機(jī)設(shè)計(jì)機(jī)械設(shè)計(jì)制造及其自動(dòng)化機(jī)械設(shè)計(jì)制造及其自動(dòng)化12-1李軍斌李軍斌常規(guī)游梁式抽油機(jī)的原理介紹常規(guī)游梁式抽油機(jī)的原理介紹l常規(guī)游梁式抽油機(jī)應(yīng)用的是曲柄搖桿機(jī)構(gòu)原理而在此四桿機(jī)構(gòu)的循環(huán)方式,有以下三種:l對(duì)稱(chēng)循環(huán)、近似對(duì)稱(chēng)循環(huán)和非對(duì)稱(chēng)循環(huán) l原理圖:基本參數(shù)的確定基本參數(shù)的確定l游梁抽油機(jī)的運(yùn)動(dòng)分析l游梁式抽油機(jī)懸點(diǎn)載荷計(jì)算l游梁式抽油機(jī)減速箱曲柄軸扭矩計(jì)算l游梁抽油機(jī)的抽汲工況l游梁式抽油機(jī)的電動(dòng)機(jī)選擇計(jì)算機(jī)構(gòu)運(yùn)動(dòng)簡(jiǎn)化機(jī)構(gòu)運(yùn)動(dòng)簡(jiǎn)化l懸點(diǎn)運(yùn)動(dòng)規(guī)律簡(jiǎn)化圖機(jī)構(gòu)關(guān)系框圖機(jī)構(gòu)關(guān)系框圖游梁式抽油機(jī)主要構(gòu)件的介紹游梁式抽油機(jī)主要構(gòu)件的介紹驢頭驢頭l驢頭用來(lái)將游梁前端的往復(fù)圓弧運(yùn)動(dòng)變?yōu)槌橛蜅U的垂直直線(xiàn)往復(fù)運(yùn)動(dòng),驢頭的圓弧半徑R應(yīng)等于前臂長(zhǎng)度,為了保證在一定沖程長(zhǎng)度下,將圓弧運(yùn)動(dòng)變?yōu)閼尹c(diǎn)的直線(xiàn)運(yùn)動(dòng),驢頭的圓弧面長(zhǎng)度應(yīng)為:l為驢頭懸點(diǎn)的最大沖程。驢頭采用腹板式結(jié)構(gòu)焊接而成,并應(yīng)用側(cè)翻讓位結(jié)構(gòu)進(jìn)行整修時(shí)的讓位。曲柄曲柄l曲柄是傳遞減速器輸出扭矩的主要部件,所以它必須具有一定的強(qiáng)度和傳動(dòng)可靠性。曲柄一般可用灰鑄鐵、球墨鑄鐵和鑄鋼制成。在曲柄平衡的抽油機(jī)上,兩件曲柄共同承受的抽油機(jī)的全部載荷,因此要求曲柄有很高的承載能力,同時(shí)為了調(diào)整方便和安全,曲柄上沒(méi)有導(dǎo)軌、擋塊、刻度線(xiàn),可以根據(jù)抽油機(jī)工作條件調(diào)整平衡塊位置,使抽油機(jī)保持平衡。擋塊可在緊固的情況下,防止平衡塊不致落下而發(fā)生事故。此次,在一系列要求下,用QT700-2制成大尺寸常規(guī)普通型曲柄。橫梁橫梁l橫梁是游梁與連桿之間力及運(yùn)動(dòng)傳遞的橋梁,它的制作有一下三種:l型鋼直接制成l焊接l鑄造為了使橫梁和連桿的連接點(diǎn)與橫梁和游梁的連接點(diǎn)在同一水平線(xiàn)上,往往將橫梁作成弓形。常規(guī)游梁機(jī)三維模型常規(guī)游梁機(jī)三維模型謝謝觀映!附錄
一種新的檢測(cè)液壓油的機(jī)械試驗(yàn)方法應(yīng)用
施密特,克勞斯
產(chǎn)品開(kāi)發(fā)和機(jī)械工程設(shè)計(jì)研究所,漢堡技術(shù)大學(xué),德國(guó)
摘 要:本文介紹了在一臺(tái)新開(kāi)發(fā)的試驗(yàn)臺(tái)上進(jìn)行一個(gè)摩擦磨損試驗(yàn),該試驗(yàn)臺(tái)開(kāi)發(fā)于涂漢堡哈爾堡,用于研究液壓油的潤(rùn)滑性能。開(kāi)發(fā)這種新的檢測(cè)方法的目的是為了更好的表述摩擦學(xué)與流體動(dòng)力機(jī)械之間的影響與聯(lián)系,采用線(xiàn)接觸研究液壓油的潤(rùn)滑性能表明,可利用摩擦、磨損和腐蝕試驗(yàn)區(qū)分不同液體的潤(rùn)滑性能。在不同的試驗(yàn)通過(guò)不斷的改進(jìn)試驗(yàn)裝置和開(kāi)發(fā)測(cè)試實(shí)驗(yàn)的全自動(dòng)控制程序來(lái)滿(mǎn)足高重復(fù)性的邊界條件。該試驗(yàn)機(jī)的開(kāi)發(fā)符合測(cè)試程序、形狀結(jié)構(gòu)簡(jiǎn)單的要求,可以從各種材料和生產(chǎn)設(shè)備公司生產(chǎn),現(xiàn)有的這類(lèi)公司都生產(chǎn)流體動(dòng)力元件。
關(guān)鍵詞:液壓 流體 潤(rùn)滑 試驗(yàn)
1.引言:
液壓油的一個(gè)非常重要特點(diǎn)的是它可能使摩擦加載面分離以減少這種連接中的摩擦磨損,試驗(yàn)測(cè)試液壓油潤(rùn)滑性能最可靠的試驗(yàn)是實(shí)地測(cè)試,即流體在典型工作條件和典型操作期間下的應(yīng)用。出于多種原因,實(shí)地測(cè)試費(fèi)時(shí)而且成本高,以及操作環(huán)境的不同應(yīng)用方法通常也會(huì)很大不同,因此實(shí)地測(cè)試的結(jié)果往往不具有通用性。這種情況導(dǎo)致流體生產(chǎn)者以及靜壓機(jī)械生產(chǎn)者必須先在測(cè)試實(shí)驗(yàn)室測(cè)試他們的產(chǎn)品,然后再去做現(xiàn)場(chǎng)試驗(yàn)。應(yīng)當(dāng)清楚地看到,只有當(dāng)他們能夠逼真的模擬出機(jī)器摩擦接觸時(shí)的狀態(tài)時(shí),實(shí)驗(yàn)室測(cè)試才能起到作用。
漢堡科技大學(xué)的產(chǎn)品開(kāi)發(fā)和機(jī)械工程設(shè)計(jì)研究所開(kāi)發(fā)了新的試驗(yàn)臺(tái)和測(cè)試方法,用于研究液壓油的潤(rùn)滑性能[1],按照DIN51389,今后的這項(xiàng)測(cè)試可能代替葉片泵試驗(yàn)[2]。該項(xiàng)目的目的是找到一個(gè)測(cè)試方法,盡可能的再現(xiàn)所有摩擦磨損對(duì)液壓機(jī)械的影響,通過(guò)簡(jiǎn)單的測(cè)試形式和試驗(yàn)臺(tái)的簡(jiǎn)單測(cè)量,從中獲得力學(xué)參數(shù)。負(fù)載條件下的摩擦系統(tǒng)內(nèi)液壓件(接觸壓力,相對(duì)運(yùn)動(dòng)形式)、速度、析構(gòu)函數(shù)和連接部分的屬性決定了連接區(qū)域的參數(shù)(溫度和幾何構(gòu)造),對(duì)摩擦系統(tǒng)的摩擦系數(shù)、臨界載荷和磨損性能產(chǎn)生主要影響。測(cè)試方法和試驗(yàn)機(jī)的開(kāi)發(fā)源自研究項(xiàng)目DGMK514[3],514-1[4]610[5]的一種系統(tǒng)方法。
2.主要測(cè)試儀器的安排
開(kāi)發(fā)新的測(cè)試方法是為了實(shí)現(xiàn)以下目的:
·使定量測(cè)試結(jié)果精度高;
·測(cè)試樣本簡(jiǎn)單,不需要特殊的制造技術(shù);
·自動(dòng)化、能耗低、測(cè)試液量小和測(cè)試時(shí)間短的測(cè)試方法。
對(duì)液壓件內(nèi)部的摩擦接觸的詳細(xì)分析是對(duì)這個(gè)新的測(cè)試方法和試驗(yàn)臺(tái)詳細(xì)說(shuō)明的基礎(chǔ)。設(shè)計(jì)方法、順序配置以及實(shí)驗(yàn)的主要發(fā)現(xiàn)如圖1所示。這臺(tái)試驗(yàn)臺(tái)的配置允許測(cè)試線(xiàn)接觸和面接觸。在研究過(guò)程中發(fā)現(xiàn),線(xiàn)接觸更有趣,能夠產(chǎn)生數(shù)據(jù)區(qū)分不同液壓油的潤(rùn)滑性能。這也是大多數(shù)的測(cè)試只使用線(xiàn)接觸數(shù)據(jù)的原因。
圖1 MPH試驗(yàn)臺(tái)-主要測(cè)試儀器的安排
液壓油的潤(rùn)滑性能量化參數(shù)如下:
·PHD,crit 壓力導(dǎo)致材料粘結(jié)掉落(金屬粘結(jié)磨損)
·μEx,average 線(xiàn)接觸的平均摩擦系數(shù)
·Vline 試樣滑塊的磨損量
這些參數(shù)的準(zhǔn)確性和重復(fù)性確定了測(cè)試液壓油潤(rùn)滑性能的優(yōu)劣程度,可分為高,中,低等。而對(duì)速度、轉(zhuǎn)矩和壓力等機(jī)械參數(shù)的精確測(cè)量、計(jì)算中考慮導(dǎo)向裝置和軸承中可能的摩擦接觸力、精確的方法測(cè)量和計(jì)算試樣的磨損體積是取得可靠結(jié)果的根本。
在研究過(guò)程中,為了改善測(cè)量的準(zhǔn)確性和可重復(fù)性,對(duì)試驗(yàn)臺(tái)做了許多的改進(jìn)。
3.試驗(yàn)條件
為了確定短期和長(zhǎng)期測(cè)試(短期試驗(yàn)是臨界載荷試驗(yàn),長(zhǎng)期試驗(yàn)是測(cè)試摩擦系數(shù)和磨損量)最佳試驗(yàn)條件做了大量的測(cè)試工作,這些測(cè)試結(jié)果表明,試驗(yàn)的起動(dòng)過(guò)程對(duì)測(cè)試結(jié)果有重要影響。
3.1起動(dòng)方法
起動(dòng)過(guò)程通過(guò)設(shè)置補(bǔ)償參數(shù)和線(xiàn)接觸中運(yùn)行控制來(lái)實(shí)現(xiàn)誤差調(diào)整。而這一起動(dòng)過(guò)程的自動(dòng)化使得后面的試驗(yàn)誤差有了明顯的改善。
3.2短期試驗(yàn)
短期試驗(yàn)是用來(lái)尋找滑動(dòng)接觸到開(kāi)始磨損材料從自然到磨損的臨界壓力PHD,crit,作用在活塞上的壓力產(chǎn)生的臨界壓力使得摩擦接觸時(shí)起潤(rùn)滑作用的潤(rùn)滑膜消失,混合摩擦變?yōu)楣腆w摩擦。圖2顯示了一個(gè)典型的短期測(cè)試的參數(shù)隨時(shí)間改變情況。
圖2 短期測(cè)試參數(shù)的典型變化
3.3長(zhǎng)期試驗(yàn)
長(zhǎng)期試驗(yàn)是用來(lái)尋找線(xiàn)接觸具體工作流體摩擦系數(shù)和試樣滑塊的損失量。所有試驗(yàn)的摩擦接觸的負(fù)載都是恒定的,這里的負(fù)載是指作用在活塞上的平均壓力,從而使得孔測(cè)試中作用于偏心軸和滑動(dòng)器線(xiàn)接觸上的力恒定。圖3顯示了一個(gè)典型的長(zhǎng)期測(cè)試的參數(shù)隨時(shí)間改變情況。
圖3 長(zhǎng)期測(cè)試參數(shù)的典型變化
4.COMPLETET系列試驗(yàn)結(jié)果
該項(xiàng)目對(duì)HL類(lèi)、HLP類(lèi)和HEES合成酯類(lèi)礦物油進(jìn)行了測(cè)試,試驗(yàn)還把測(cè)試對(duì)象擴(kuò)大到以多級(jí)機(jī)油和齒輪油為主的礦產(chǎn)和酯類(lèi)?,F(xiàn)已完成測(cè)試階段的主要任務(wù)是找出這些類(lèi)型油液的不同潤(rùn)滑性能,因?yàn)樗鼈兛赡艽碇煌?lèi)型。最重要的一點(diǎn)是相同的流體多次測(cè)試結(jié)果要在一個(gè)狹窄的變換范圍,可查看平均值小偏離。本文介紹了有關(guān)6種不同類(lèi)型液壓油的測(cè)試結(jié)果,其中一種HEES型,三種HLP型和兩種HL類(lèi)型。所有油液都有抗腐蝕和老化添加劑,在HEES類(lèi)和HLP類(lèi)添加了不同濃度的EP、AW添加劑。
圖4中的表格提供一個(gè)典型測(cè)試的范圍絕對(duì)值。重要的是要看到,三次試驗(yàn)得出的臨界壓力和平均摩擦系數(shù)或多或少接近平均值,而相同精度條件,相同油液下不同試驗(yàn)試樣的體積損失顯示較大偏差。它也可以看出,臨界載荷、平均摩擦系數(shù)和體積損失之間有一定的對(duì)應(yīng)關(guān)系。另一方面,該表顯示,比較流體相對(duì)潤(rùn)滑能力并不是很容易的,因?yàn)榇罅康脑囼?yàn)結(jié)果都必須考慮進(jìn)去。因此,不同的產(chǎn)生了不同的比較方式,這也顯示在圖4,如圖所示基于測(cè)試結(jié)果的等距介紹,數(shù)字橢球代表不同流體測(cè)量值,所有值以HF-1類(lèi)油液作為參考基準(zhǔn)。
圖4 試驗(yàn)結(jié)果的絕對(duì)值和等距表示
圖5顯示了圖4三維圖可以清楚的看到用MPH試驗(yàn)臺(tái)測(cè)試不但能夠區(qū)分不同類(lèi)別的油液而且同類(lèi)的中的不同油液也能區(qū)分。
圖5 結(jié)果參數(shù)的三維圖顯示(見(jiàn)圖4)的結(jié)果參數(shù)
結(jié)論
通過(guò)MPH項(xiàng)目大量的試驗(yàn)結(jié)果表明,MPH試驗(yàn)臺(tái)完全有測(cè)試區(qū)分液壓油的潤(rùn)滑性能的能力,隨著試驗(yàn)臺(tái)的設(shè)計(jì)改進(jìn)和全自動(dòng)控制的發(fā)展,試驗(yàn)臺(tái)測(cè)試結(jié)果的重復(fù)性有所改善,通過(guò)最近試驗(yàn)臺(tái)的試驗(yàn)可以看出,摩擦系數(shù)和臨界壓力值平均偏差不超過(guò)±10%,試樣磨損量偏差范圍為最大量的±15%,這可通過(guò)更準(zhǔn)確的測(cè)量技術(shù)來(lái)減少[6][7]。測(cè)試結(jié)果的重復(fù)性是MPH項(xiàng)目的要點(diǎn),已取得的精確度可以用于其他用來(lái)測(cè)試液壓油試驗(yàn)的比較標(biāo)準(zhǔn)。在葉片泵試驗(yàn)也就是FZG試驗(yàn)[8]中沒(méi)有確定試運(yùn)行的最低數(shù)量,測(cè)試結(jié)果中也沒(méi)有精確要求。根據(jù)這兩項(xiàng)測(cè)試的標(biāo)準(zhǔn)流體分類(lèi)只有一個(gè)試運(yùn)行是必要的,這導(dǎo)致的結(jié)論是,假設(shè)至少每流體進(jìn)行三次試運(yùn)行,MPH試驗(yàn)臺(tái)測(cè)試能比其他測(cè)試提供更好的可靠數(shù)據(jù)。
參考文獻(xiàn)
[1] Kessler, M., Entwicklung eines Testverfahrens zur mechanischen Prufung von Hydraulikflussigkeiten, Dissertation, Fortschritt-Berichte VDI, Reihe 1, Nr. 335, 2000.
[2] DIN 51389, Mechanische Prufung von Hydraulikflussigkeiten in der Flugelzellenpumpe, Deutsches Institut fur Normung e.V., Beuth Verlag Berlin, 1982.
[3] Kessler, M., Feldmann, D.G., Mechanische Prufung von Hydraulikflussigkeiten, DGMK Forschungsbericht 514, Hamburg, Juli 1999.
[4] Kessler, M., Feldmann, D.G., Mechanische Prufung von Hydraulikflussigkeiten II, DGMK Forschungsbericht 514-1, Hamburg, Sept. 2001.
[5] Schmidt, J.; Feldmann, D.G.; Padgurskas, Mechanische Prufung von Hydraulikflussigkeiten, DGMK Forschungsbericht 610, Hamburg, 2006.
[6] Feldmann, D.G., Padgurskas, J., Analysis of the Lubrication Capabilities of Hydraulic Fluids using a Test Method with Line Contact, Engineering Materials & Tribology 2004, Riga, 23.-24. Sept. 2004.
[7] Schmidt, J., Feldmann, D.G., Padgurskas, J., Application of a new test procedure for mechanical testing of hydraulic fluids, 5. International Fluid Power Conference, Vol. 2, p.269-280, Aachen, 20.-22. March 2006.
[8] DIN 51354, FZG-Zahnrad-Verspannungs-Prufmaschine, Deutsches Institut fur Normung e.V., Beuth Verlag Berlin, 1990
10
Proceedings of the International Conference BALTTRIB2007 APPLICATION OF A NEW TEST PROCEDURE FOR MECHANICAL TESTING OF HYDRAULIC FLUIDS J. Schmidt, D. Krause Institute for Product Development and Mechanical Engineering Design, Hamburg University of Technology, Germany Abstract: This paper describes a friction and wear test in a newly developed test machine, which was developed at the TU Hamburg-Harburg to investigate the lubricating capability of hydraulic fluids. The aim of the development of the new test procedure is a better representation of the tribological contacts and effects in fluid power machinery. The investigation of the lubrication capabilities of hydraulic fluids using a line contact showed, that a distinction between different fluids regarding their lubrication capabilities can be made, using friction-, wear- and erosion tests (galling). The high reproducibility of the boundary conditions during different tests was achieved by steady design modifications of the test rig and the development of a computer program for fully-automatic control of the test procedure. The developed test machine fulfils the requirements of a simple test procedure and simply shape of test specimen, which could be produced from principally every type of material and production machines, existing in every company that produce fluid power components. Keywords: Hydraulic, fluid, lubrication, testing 1. INTRODUCTION A very important feature of a hydraulic fluid is its potential to separate the surfaces of a loaded tribo-contact and by this to reduce friction and wear in this contact. The most reliable test to investigate the lubricating capability of a hydraulic fluid is the field test, i.e. the application of the fluid under typical operating conditions and for typical operating periods. For many reasons field tests are time consuming and costly, and the operating condition of different applications typically will be very different so that results from one application might not be transferable to another application. This situation leads to the necessity for fluid producers as well as for the producers of hydrostatic machinery to test their product in a laboratory test before they go for a field test. It should be clear that laboratory tests are only helpful if they reproduce the situation in the tribo-contact of the real machine to a high extend. The Institute for Product Development and Mechanical Engineering Design at the Hamburg University of Technology has developed a new test procedure and a test machine to investigate the lubricating capability of hydraulic fluids 1. In future this test possibly can replace the vane pump test according to DIN 51389 2. The aim of the project was to find a test procedure which reproduces the totality of wear relevant tribological effects in hydrostatic machinery as good as possible, using simply shaped test specimen and a test machine, which allows an easy measurement of the mechanical parameters to derive from these friction and wear. The load conditions of the tribo-systems within a hydrostatic machine (contact pressure, type of relative movement) and velocity and destructor and the properties of the contact partners define the parameters in the contact zone (temperature and geometry) which have the main impact on friction coefficient, critical load and wear performance of the tribo-system. The test procedure and test machine was developed by a systematic approach in research projects DGMK 514 3, 514-1 4 and 610 5. 2. PRINCIPAL ARANGEMENT OF THE TEST APPARATUS The aim of the development of a new test procedure was to achieve ? reproducible quantitative test results with high accuracy, ? simple test specimen, which do not require special manufacturing technologies, ? a test procedure which can be automated and ? low energy consumption, small volume of test fluid and short test time. A detailed analysis of the tribo-contacts in hydrostatic machines was the base for a specification for this new test procedure and machine. Using design methodology and systematic design approach a test principal was found, which is shown in Fig. 1. The arrangement of the test apparatus allows the investigation of line contact and area contact. During the research project it was found, that the line contact is the more interesting one and generates data which allow to classify lubricating capabilities of different fluids; this is the reason why the majority of the tests was only using data from the line contact. To quantify the lubricating capability of a hydraulic fluid the following parameters are used: ? pHD,crit critical pressure which leads to adhesive material removal (“galling”), ? Ex,average average friction coefficient in the line contact, ? Vline wear volume of the test specimen slider. The accuracy and the reproducibility of these parameters define to a high extend how good the tested fluids can be classified as low, medium and high lubricating fluids. Exact measurements of the mechanical parameters as speed, torque and pressure, the possibility to calculate contact forces having friction in guiding devices and bearings in the calculation and a sophisticated method to measure and calculate the wear volume at the slider are the basis to achieve adequate results. During the research project a number of design changes have been made with the test machine to improve the accuracy and reproducibility of the measurements. 3. TEST CONDITIONS To define the optimal test conditions for the short term and long term test (short term test is the test for critical load, long term test is the test for friction coefficient and wear volume) a great number of tests were done. During these tests it was found that the starting process for the test is of significant influence on the results of the tests. 3.1 Start procedure The parameters of the starting procedure have to be such that initial damages of the test specimen are avoided and a controlled running in of the line contact is achieved. An automation of this starting procedure lead to a significant improvement of the following tests. 3.2 Short term test procedure Short term tests are used to find the critical pressure pHD,crit, which is the pressure when spontaneous and intensive adhesive material transfer between the sliding contacts starts galling. The pressure on the piston produces a critical pressure within the tribo-contact at which the lubricating film between the contacting services disappears and mixed friction changes to friction of solids. Figure 2 shows the developing of the test parameters versus time for a typical short term test. pistontest specimen slider(line contact)cylinder(excentric)shaft with excentricshaft end test chamber Figure 1. MPH test rig - principal arrangement of the test apparatus 3.3 Endurance test procedure The endurance test is used to find the fluids specific work friction coefficient of the line contact and the volume loss of the test specimen slider. The load of the tribo-contact is constant for all tests; load means the average pressure on the piston which is held constant during the hole test to produce a constant force in the line contact between slider and cylinder (excentric). Figure 3 shows the developing of the test parameters within the endurance test. end ofstart proceduretest duration hpressure over piston PHDbartemperature tribo-contact EXCtemperature tank tankCtorque excentric TEX Nmaverage friction coefficient EX- Figure 3. Typical developing of the test parameters within a endurance test galling“TEX = 0,5beginning ofshort term testend of startproceduretest duration hpressure over piston PHDbartemperature tribo-contact EXCtemperature tank tankCtorque excentric TEX Nmaverage friction coefficient EX- Figure 2. Typical developing of the test parameters within a short term test4. RESULTS FROM COMPLETET TEST SERIES Within the project mineral oil based hydraulic fluids of HL- and HLP-type and synthetic esters of HEES-types were tested; at this time the tests are extended to mineral and ester based multigrade motor oils and gear oils. Main task of the by now completed tests was to demonstrate different lubricating capabilities of these types of fluids as they should be expected for the different types. The most important point was to demonstrate that the results of multiple tests with the same fluid are in a narrow range, i.e. show small deviations from an average value. This paper reports about the test results for six different types of hydraulic fluids, one fluid of HEES-type, three fluids of type HLP and two fluids of type HL. All fluids had corrosion and anti-aging additives, the HEES-type and the HLP-type fluids were equipped with ep- and aw-additive packages in different concentrations. The table in Fig. 4 gives information about the absolute values of the tests of a typical test range. It is important to see that the critical pressure and the average friction coefficient of three test runs are more or less close to an average value while the volume loss of the slider shows bigger deviations for different tests with the same fluid under the exact same conditions. It can also be seen that there is a certain correspondence between critical load, average friction coefficient and volume loss. On the other hand the table shows, that a relative comparison of the fluids lubricating capabilities is not very easy, because a great number of test results have to be taken into account. Therefore a different presentation of the results has been developed, which is also shown in Fig. 4. The diagram shows the isometric presentation of a results base. In this figure the ellipsoids represent the limits of the measured values for the different fluids; all values are referred to the HF-1 fluid as a reference. HF-2(HL)HF-6(HEES)HF-4(HLP)HF-1(HL)HF-3(HLP)HF-5(HLP)rel. friction coefficient %rel. crit. pressure %rel. wear volume % Figure 4. Absolute values and isometric representation of the test results Figure 5 shows the projections of the three dimensional diagram of figure 4 and demonstrate clearly that the measurement with the MPH test rig allow a clear differentiation of not only fluids of different classes but also of fluids within one class. HF-2(HL)HF-6(HEES)HF-4(HLP)HF-1(HL)HF-3(HLP)HF-5(HLP)rel. Reibungskoeffizient %HF-1: reference fluidrel. wear volume %rel. friction coefficient %HF-2(HL)HF-6(HEES)HF-4(HLP)HF-1(HL)HF-3(HLP)HF-5(HLP)HF-1: reference fluidrel. crit. pressure %rel. wear volume %HF-2(HL)HF-6(HEES)HF-4(HLP)HF-1(HL)HF-3(HLP)HF-5(HLP)HF-1: reference fluidrel. friction coefficient %rel. crit. pressure % Figure 5. Projections of the three dimensional diagram (see fig. 4) of the result parameters CONCLUSION The results of a high number of tests within the MPH-project have shown that it is possible to differentiate the lubricating capability of hydraulic fluids with the MPH test rig. With the design improvement of the test rig and the development of a fully automatic test rig control the reproducibility of test results could be improved. Looking to recent tests with the actual test rig it could be seen, that the values for friction coefficient and critical pressure do not differ more than 10% from the average. The wear volume shows bigger deviations within a test sample with a maximum of 15 % which possibly can be reduced by more accurate measurement techniques 6, 7. Reproducibility of test results was a major point for the MPH-project. The achieved accuracies must be seen in comparison to accuracies requirements of other tests which are used to test hydraulic fluids. The vane pump tests and also the FZG-test 8 do not define a minimum number of test runs and no accuracies in the test results. According to the standards in both tests only one test run is necessary for a classification of a fluid. This leads to the conclusion that test results with the MPH test rig and procedure may give better reliable data about the lubrication capability than other test procedures used assuming at minimum 3 test runs per fluid. REFERENCES 1 Kessler, M., Entwicklung eines Testverfahrens zur mechanischen Prfung von Hydraulikflssigkeiten, Dissertation, Fortschritt-Berichte VDI, Reihe 1, Nr. 335, 2000. 2 DIN 51389, Mechanische Prfung von Hydraulikflssigkeiten in der Flgelzellenpumpe, Deutsches Institut fr Normung e.V., Beuth Verlag Berlin, 1982. 3 Kessler, M., Feldmann, D.G., Mechanische Prfung von Hydraulikflssigkeiten, DGMK Forschungsbericht 514, Hamburg, Juli 1999. 4 Kessler, M., Feldmann, D.G., Mechanische Prfung von Hydraulikflssigkeiten II, DGMK Forschungsbericht 514-1, Hamburg, Sept. 2001. 5 Schmidt, J.; Feldmann, D.G.; Padgurskas, Mechanische Prfung von Hydraulikflssigkeiten, DGMK Forschungsbericht 610, Hamburg, 2006. 6 Feldmann, D.G., Padgurskas, J., Analysis of the Lubrication Capabilities of Hydraulic Fluids using a Test Method with Line Contact, Engineering Materials & Tribology 2004, Riga, 23.-24. Sept. 2004. 7 Schmidt, J., Feldmann, D.G., Padgurskas, J., Application of a new test procedure for mechanical testing of hydraulic fluids, 5. International Fluid Power Conference, Vol. 2, p.269-280, Aachen, 20.-22. March 2006. 8 DIN 51354, FZG-Zahnrad-Verspannungs-Prfmaschine, Deutsches Institut fr Normung e.V., Beuth Verlag Berlin, 1990. Author for contacts: Dr.-Ing. Jens Schmidt, Institute for Product Development and Mechanical Engineering Design, Hamburg University of Technology, Denickestrae 17, 21073 Hamburg, Germany. Phone: +49 40 428783131, Fax +49 40 428782296, E-Mail: jens.schmidttu-harburg.de.
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