振動篩設(shè)計(jì)【含CAD高清圖紙和說明書】

【溫馨提示】 dwg后綴的文件為CAD圖，可編輯，無水印，高清圖，壓縮包內(nèi)文檔可直接點(diǎn)開預(yù)覽，需要原稿請自助充值下載，請見壓縮包內(nèi)的文件及預(yù)覽，所見才能所得，請細(xì)心查看有疑問可以咨詢QQ：414951605或1304139763 連桿機(jī)構(gòu)連桿存在于車庫門裝置，汽車擦裝置，齒輪移動裝置中。它是一給予很少關(guān)注的機(jī)械工程學(xué)的組成部分。聯(lián)桿是具有兩個(gè)或更多運(yùn)動副元件的剛性機(jī)構(gòu)，用它的連接是為了傳遞力或運(yùn)動。在每個(gè)機(jī)器中，在運(yùn)動期間，聯(lián)桿或者占據(jù)一相對于地面的固定位置或者作為一個(gè)整體來承載機(jī)床。這些連桿是機(jī)器主體被稱為固定連桿。基于由循環(huán)的或滑動的分界面的元件連接的布局被稱作連接。這類旋轉(zhuǎn)的和菱形的連接機(jī)構(gòu)被稱作低副。高副基于接觸點(diǎn)或彎曲分界面的。低副的例子包括鉸鏈循環(huán)的軸承和滑道以及萬向接頭。高副的例子包括通信區(qū)主站和齒輪。動力分析得到，根據(jù)機(jī)件幾何學(xué)有利條件研究是一特別的機(jī)構(gòu),它是識別輸入角速度和角加速度等等的運(yùn)動。運(yùn)動合成作用是處理機(jī)構(gòu)設(shè)計(jì)到完成完成要求的任務(wù)。這里, 兩者的選擇類型和新的機(jī)制尺寸可能是運(yùn)動學(xué)的綜合部份。平面的、空間性的和球面運(yùn)動機(jī)構(gòu)平面的機(jī)構(gòu)是其中全部的點(diǎn)描述平面曲線是間隔和全部平面是共面的， 大多數(shù)連桿和機(jī)構(gòu)被設(shè)計(jì)成這樣，例如刨床體系。主要的理由是這個(gè)平面的體系對工程師來說更方便。計(jì)算機(jī)綜合法對工程師來說空間性的裝置會有更多的麻煩。平面低副機(jī)構(gòu)被稱作二維的連接裝置。平面的連接僅僅包括旋轉(zhuǎn)的和一對等截面的使用?？臻g機(jī)構(gòu)沒有對相對運(yùn)動的點(diǎn)的限制。平面的和球面運(yùn)動機(jī)構(gòu)是亞墊鐵等鍛工工具的空間機(jī)構(gòu)?？臻g機(jī)構(gòu)的連接不是被認(rèn)為這時(shí)候被記錄。球面運(yùn)動機(jī)構(gòu)有一接觸點(diǎn)接通各個(gè)連桿，它是不動的并且平穩(wěn)點(diǎn)在所有當(dāng)中聯(lián)桿場中工作。在所有機(jī)件當(dāng)中，運(yùn)動是同心并且由他們的盲區(qū)接通球面表現(xiàn)出來，它是集中于普遍的定位?？臻g機(jī)構(gòu)的連接認(rèn)為不是這時(shí)候被記錄?？蓜有赃B桿在運(yùn)動中所表現(xiàn)的自由度數(shù)是一個(gè)很重要的問題。為了使裝置被送到指定位置應(yīng)控制獨(dú)立的活動自由度。它可能是由桿的數(shù)量和連接方式?jīng)Q定的。一自由連桿通常有3個(gè)自由度(x , y, )。由于自由度數(shù)的限制在n連桿裝置中，通常把一個(gè)桿固定。自由度數(shù)=3(n-1).連接二連桿的機(jī)構(gòu)有兩個(gè)自由度約束的增加。有兩個(gè)約束的二連桿連接，其中一個(gè)自由度是來約束這個(gè)系統(tǒng)的。有一個(gè)約束的連桿機(jī)構(gòu)的自由度是j1，有兩個(gè)約束的連桿機(jī)構(gòu)的自由度是j2。這個(gè)系統(tǒng)的自由度數(shù)可表示為 m = 3 (n-1) - 2 j 1 - j 2以下為可動的連桿機(jī)構(gòu)裝置的示例0是這個(gè)體系中可動的機(jī)構(gòu)。系統(tǒng)中僅僅由一連桿的位置固定可以將可動1安裝在固定位置。系統(tǒng)中需要一個(gè)可動的2與兩個(gè)連桿來確定連接位置。這是個(gè)一般的規(guī)則，但也存在例外，它可以作為一個(gè)可動性連桿布局的很有用的參考。格朗定律當(dāng)設(shè)計(jì)一連接連桿時(shí)，在連續(xù)地旋轉(zhuǎn)連桿處，例如由一馬達(dá)輸入時(shí)，連線可以自由地旋轉(zhuǎn)完全運(yùn)行驅(qū)動是很重要的。如果連桿鎖在任一點(diǎn)則方案不會工作。四桿聯(lián)動機(jī)構(gòu)和grashof定律對這個(gè)情況進(jìn)行提供了簡單的測驗(yàn)。格朗的定律如下：b(短的鏈環(huán))+c(長的鏈環(huán))a+d四個(gè)典型的四連桿機(jī)構(gòu)注意：如果非之上情況則只有連桿滑塊機(jī)構(gòu)可行。四連桿機(jī)構(gòu)的優(yōu)點(diǎn)四連桿機(jī)構(gòu)按比例增大了施加在主動桿上的輸入扭矩?？梢宰C明其正比例系數(shù)是Sin( )其中是c、d 兩桿之間的角度。反比例于sin( )。其中是b、c兩桿之間的角度。這些角度不恒定，因此很明顯，機(jī)構(gòu)的優(yōu)點(diǎn)是規(guī)律性的變幻。 如下圖顯示當(dāng)角度=0 o或則=180 o時(shí)接近于無限增矩機(jī)構(gòu)。這些位置是極限位置， 這些位置使四連桿機(jī)構(gòu)可以用于夾具機(jī)構(gòu)。角被叫做“傳輸角度”。當(dāng)傳輸角度的sin值趨于無限小時(shí)，機(jī)構(gòu)的增距接近于0。在這樣的情況下連桿容易因?yàn)楹苄〉哪Σ炼a(chǎn)生自鎖。一般來說，當(dāng)使用四連桿機(jī)構(gòu)時(shí)，避免采用低于400到500的傳輸角度。弗洛伊德方程這些方程提供了確定內(nèi)外連桿位置及連桿長度的簡單代數(shù)學(xué)方法。假設(shè)四連桿機(jī)構(gòu)如下所示：四連桿的位置矢量如下：l 1 + l 2 + l 3 + l 4 = 0 水平位移方程：l 1 cos 1 + l 2 cos 2 + l 3 cos 3 + l 4 cos 4 = 0 垂直位移方程：l 1 sin 1 + l 2 sin 2 + l 3 sin 3 + l 4 sin 4 = 0 假設(shè) 1 = 1800 then sin 1 = 0 and cos 1 = -1 Therefore 而l 1 + l 2 cos 2 + l 3 cos 3 + l 4 cos 4 = 0 l 2 sin 2 + l 3 sin 3 + l 4 sin 4 = 0方程兩邊同時(shí)消去l 3：l 32 cos 2 3 = (l 1 - l 2 cos 2 - l 4 cos 4 ) 2 l 32 sin 2 3 = ( - l 2 sin 2 - l 4 sin 4) 2由以上兩式可得如下關(guān)系cos ( 2 - 4 ) = cos 2 cos 4 + sin 2sin 4 ) and sin2 + cos2 = 1結(jié)果如下所示弗洛伊德方程得出這樣的參數(shù)關(guān)系結(jié)論K 1 cos 2 + K2 cos 4 + K 3 = cos ( 2 - 4 )K1 = l1 / l4 K2 = l 1 / l 2 K3 = ( l 32 - l 12 - l 22 - l 2 4 ) / 2 l 2 l 4 這個(gè)方程符合四連桿機(jī)構(gòu)的有限元分析。如果外連桿機(jī)構(gòu)中的三個(gè)參量已知，那么可以由公式得出其他連桿的位置與長度參數(shù)。連桿的速度矢量桿上一點(diǎn)的速度必須與桿的軸向垂直否則連桿的長度將產(chǎn)生變化。在B下的連桿速度為vAB = .AB，方向垂直于AB桿，速度矢量圖如下： 考慮到下面四連桿機(jī)構(gòu)的實(shí)例，速度矢量圖表示如下：1）A和D相連并固定，相對加速度=0，A和D位于同一點(diǎn)2）B點(diǎn)相對A點(diǎn)加速是vAB = .AB垂直于AB桿。3）C點(diǎn)相對D點(diǎn)速度通過D點(diǎn)垂直于CD桿。4）P店讀速度由速度矢量圖和比例bp/bc = BP/BC獲得。速度矢量簡圖如下所示：連桿上滑塊的速度認(rèn)為B滑塊繞著A在連桿上滑動，滑塊瞬間位移到B點(diǎn)。B點(diǎn)的速度為A = .AB并垂直于線的方向。其鏈接滑塊和速度矢量圖如下所示： 連桿的加速矢量桿上一點(diǎn)相對另一點(diǎn)的加速矢量由兩部分組成：1）向心加速度由其角速度和連桿長度決定為 2.L2）角加速度由連桿角加速度度決定以下圖表顯示如何到構(gòu)造一矢量圖表下圖顯示如何構(gòu)造單連桿機(jī)構(gòu)的加速矢量向心加速度ab = 2.AB方向指向圓心，角加速度為bb = . AB方向垂直于桿。下圖顯示如何構(gòu)造四連桿機(jī)構(gòu)的加速矢量畫法1）. A和D相連并固定，相對加速度=0(a,d同)2）. B點(diǎn)相對A點(diǎn)加速在上面的桿上畫出3）. B點(diǎn)相對C點(diǎn)向心加速度為：B = v 2CB，方向指向B。4）. B點(diǎn)相對C點(diǎn)角加速度未知但是方向已知5）. C點(diǎn)相對D點(diǎn)向心加速度為：D = v 2CD， 與d( dc2)方向相同。6）. C點(diǎn)相對D點(diǎn)角加速度未知但是方向已知7）. 通過線c1 和c 2的交叉點(diǎn)找出cP點(diǎn)的速度由比例bp/bc=bp/bc獲得，且其絕對加速度為P = ap。下面的圖表顯示其構(gòu)造方式和轉(zhuǎn)桿上滑塊的加速矢量圖。兩個(gè)滑塊之間呈dw角。連桿上點(diǎn)的速度與B點(diǎn)變化一致，變化范圍為.r =a b 1 到 ( + d) (r +dr) = a b 2b1b2速度的變化分為沿桿方向的r d 及沿其切線方向的dr + r d?；瑝K上B點(diǎn)的速度與連桿上相關(guān)點(diǎn)的變化有關(guān)v = a b 3 to v + dv = a b 4.沿著dv與v d 方向速度的變化= b3b4 。在速度切線方向總變化= dv- r d 加速度 = dv / dt = r d / dt = a - 2 r 速度在正切方向總變化= v d + dr + r 正切加速= v d / dt + dr/dt + r d / dt = v + v + r = r + 2 v 加速矢量圖表顯示如下：注: 其中2 v代表塊的正切加速度。每當(dāng)鏈接滑通過一個(gè)旋轉(zhuǎn)的塊，相對一致點(diǎn)沿著一旋轉(zhuǎn)鏈環(huán)一塊滑動。- 7 -Link mechanismLinkages include garage door mechanisms, car wiper mechanisms, gear shift mechanisms.They are a very important part of mechanical engineering which is given very little attention.A link is defined as a rigid body having two or more pairing elements which connect it to other bodies for the purpose of transmitting force or motion . In every machine, at least one link either occupies a fixed position relative to the earth or carries the machine as a whole along with it during motion. This link is the frame of the machine and is called the fixed link.An arrangement based on components connected by rotary or sliding interfaces only is called a linkage. These type of connections, revolute and prismatic, are called lower pairs. Higher pairs are based on point line or curve interfaces. Examples of lower pairs include hinges rotary bearings, slideways , universal couplings. Examples of higher pairs include cams and gears.Kinematic analysis, a particular given mechanism is investigated based on the mechanism geometry plus factors which identify the motion such as input angular velocity, angular acceleration, etc. Kinematic synthesis is the process of designing a mechanism to accomplish a desired task. Here, both choosing the types as well as the dimensions of the new mechanism can be part of kinematic synthesis.Planar, Spatial and Spherical MechanismsA planar mechanism is one in which all particles describe plane curves is space and all of the planes are co-planar.The majority of linkages and mechanisms are designed as planer systems. The main reason for this is that planar systems are more convenient to engineer. Spatial mechanisma are far more complicated to engineer requiring computer synthesis. Planar mechanisms ultilising only lower pairs are called planar linkages. Planar linkages only involve the use of revolute and prismatic pairsA spatial mechanism has no restrictions on the relative movement of the particles. Planar and spherical mechanisms are sub-sets of spatial mechanisms.Spatial mechanisms / linkages are not considered on this pageSpherical mechanisms has one point on each linkage which is stationary and the stationary point of all the links is at the same location. The motions of all of the particles in the mechanism are concentric and can be repesented by their shadow on a spherical surface which is centered on the common location.Spherical mechanisms /linkages are not considered on this pageMobilityAn important factor is considering a linkage is the mobility expressed as the number of degrees of freedom.The mobility of a linkage is the number of input parameters which must be controlled independently in order to bring the device to a set position.It is possible to determine this from the number of links and the number and types of joints which connect the links.A free planar link generally has 3 degrees of freedom (x , y, ). One link is always fixed so before any joints are attached the number of degrees of freedom of a linkage assembly with n links = DOF = 3 (n-1) Connecting two links using a joint which has only on degree of freedom adds two constraints. Connecting two links with a joint which has two degrees of freedom include 1 restraint to the systems. The number of 1 DOF joints = say j 1 and the number of joints with two degrees of freedom = say j 2. The Mobility of a system is therefore expressed as mobility = m = 3 (n-1) - 2 j 1 - j 2Examples linkages showing the mobility are shown below. A system with a mobility of 0 is a structure. A system with a mobility of 1 can be fixed in position my positioning only one link. A system with a mobility of 2 requires two links to be positioned to fix the linkage position.This rule is general in nature and there are exceptions but it can provide a very useful initial guide as the the mobility of an arrangement of links.Grashofs LawWhen designing a linkage where the input linkage is continuously rotated e.g. driven by a motor it is important that the input link can freely rotate through complete revolutions. The arrangement would not work if the linkage locks at any point. For the four bar linkage Grashofs law provides a simple test for this conditionGrashofs law is as follows: For a planar four bar linkage, the sum of the shortest and longest links cannot be greater than the sum of the remaining links if there is to be continuous relative rotation between two members.Referring to the 4 inversions of a four bar linkage shown below .Grashofs law states that one of the links (generally the shortest link) will be able to rotate continuously if the following condition is met. b (shortest link ) + c(longest link) a + dFour Inversions of a typical Four Bar LinkageNote: If the above condition was not met then only rocking motion would be possible for any link.Mechanical Advantage of 4 bar linkageThe mechanical advantage of a linkage is the ratio of the output torque exerted by the driven link to the required input torque at the driver link. It can be proved that the mechanical advantage is directly proportional to Sin( ) the angle between the coupler link(c) and the driven link(d), and is inversely proportional to sin( ) the angle between the driver link (b) and the coupler (c) .These angles are not constant so it is clear that the mechanical advantage is constantly changing.The linkage positions shown below with an angle = 0 o and 180 o has a near infinite mechanical advantage.These positions are referred to as toggle positions. These positions allow the 4 bar linkage to be used a clamping tools.The angle is called the transmission angle. As the value sin(transmission angle) becomes small the mechanical advantage of the linkage approaches zero. In these region the linkage is very liable to lock up with very small amounts of friction.When using four bar linkages to transfer torque it is generally considered prudent to avoid transmission angles below 450 and 500.In the figure above if link (d) is made the driver the system shown is in a locked position.The system has no toggle positions and the linkage is a poor design Freudensteins EquationThis equation provides a simple algebraic method of determining the position of an output lever knowing the four link lengths and the position of the input lever. Consider the 4 -bar linkage chain as shown below. The position vector of the links are related as follows l 1 + l 2 + l 3 + l 4 = 0 Equating horizontal distances l 1 cos 1 + l 2 cos 2 + l 3 cos 3 + l 4 cos 4 = 0 Equating Vertical distances l 1 sin 1 + l 2 sin 2 + l 3 sin 3 + l 4 sin 4 = 0 Assuming 1 = 1800 then sin 1 = 0 and cos 1 = -1 Therefore - l 1 + l 2 cos 2 + l 3 cos 3 + l 4 cos 4 = 0 and . l 2 sin 2 + l 3 sin 3 + l 4 sin 4 = 0 Moving all terms except those containing l 3 to the RHS and Squaring both sides l 32 cos 2 3 = (l 1 - l 2 cos 2 - l 4 cos 4 ) 2l 32 sin 2 3 = ( - l 2 sin 2 - l 4 sin 4) 2Adding the above 2 equations and using the relationshipscos ( 2 - 4 ) = cos 2 cos 4 + sin 2sin 4 ) and sin2 + cos2 = 1the following relationship results.Freudensteins Equation results from this relationship as K 1 cos 2 + K2 cos 4 + K 3 = cos ( 2 - 4 )K1 = l1 / l4 K2 = l 1 / l 2 K3 = ( l 32 - l 12 - l 22 - l 2 4 ) / 2 l 2 l 4 This equation enables the analytic synthesis of a 4 bar linkage. If three position of the output lever are required corresponding to the angular position of the input lever at three positions then this equation can be used to determine the appropriate lever lengths using three simultaneous equations. Velocity Vectors for LinksThe velocity of one point on a link must be perpendicular to the axis of the link, otherwise there would be a change in length of the link.On the link shown below B has a velocity of vAB = .AB perpendicular to A-B. The velocity vector is shown. Considering the four bar arrangement shown below. The velocity vector diagram is built up as follows: As A and D are fixed then the velocity of D relative to A = 0 a and d are located at the same point The velocity of B relative to a is vAB = .AB perpendicular to A-B. This is drawn to scale as shown The velocity of C relative to B is perpedicular to CB and passes through b The velocity of C relative to D is perpedicular to CD and passes through d The velocity of P is obtained from the vector diagram by using the relationship bp/bc = BP/BC The velocity vector diagram is easily drawn as shown. Velocity of sliding Block on Rotating LinkConsider a block B sliding on a link rotating about A. The block is instantaneously located at B on the link.The velocity of B relative to A = .AB perpendicular to the line. The velocity of B relative to B = v. The link block and the associated vector diagram is shown below. Acceleration Vectors for LinksThe acceleration of a point on a link relative to another has two components: 1) the centripetal component due to the angular velocity of the link. 2.Length 2) the tangential component due to the angular acceleration of the link. The diagram below shows how to to construct a vector diagram for the acceleration components on a single link.The centripetal acceleration ab = 2.AB towards the centre of rotation. The tangential component bb = . AB in a direction perpendicular to the link. The diagram below shows how to construct an acceleration vector drawing for a four bar linkage. For A and D are fixed relative to each other and the relative acceleration = 0 ( a,d are together ) The acceleration of B relative to A are drawn as for the above link The centripetal acceleration of C relative to B = v 2CB and is directed towards B ( bc1 ) The tangential acceleration of C relative to B is unknown but its direction is known The centripetal acceleration of C relative to D = v 2CD and is directed towards d( dc2) The tangential acceleration of C relative to D is unknown but its direction is known. The intersection of the lines through c1 and c 2 locates c The location of the acceleration of point p is obtained by proportion bp/bc = BP/BC and the absolute acceleration of P = ap The diagram below shows how to construct and acceleration vector diagram for a sliding block on a rotating link. The link with the sliding block is drawn in two positions.at an angle dThe velocity of the point on the link coincident with B changes from .r =a b 1 to ( + d) (r +dr) = a b 2 The change in velocity b1b2has a radial component r d and a tangential component dr + r d The velocity of B on the sliding block relative to the coincident point on the link changes from v = a b 3 to v + dv = a b 4.The change in velocity = b3b4 which has radial components dv and tangential components v d The total change in velocity in the radial direction = dv- r d Radial acceleration = dv / dt = r d / dt = a - 2 r The total change in velocity in the tangential direction = v d + dr + r Tangential acceleration = v d / dt + dr/dt + r d / dt = v + v + r = r + 2 v The acceleration vector diagram for the block is shown belowNote : The term 2 v representing the tangential acceleration of the block relative to the coincident point on the link is called the coriolis component and results whenever a block slides along a rotating link and whenever a link slides through a swivelling block- 9 -一、課題的目的、意義、國內(nèi)外現(xiàn)狀及發(fā)展方向1、目的該振動篩的篩分物料為球磨機(jī)產(chǎn)品。該產(chǎn)品的大小不是很平均，為了做出更符合要求的物料就需要用振動篩來將球磨機(jī)產(chǎn)品進(jìn)一步細(xì)分，將不符合要求的物料從新用球磨機(jī)磨小。經(jīng)過這樣的反復(fù)處理最終將物料全部做成符合要求的產(chǎn)品1。2、意義礦山機(jī)械產(chǎn)品屬于小批量、多品種、使用面廣的機(jī)械設(shè)備，按用途可分為采掘設(shè)備、提升設(shè)備、礦用車輛、破碎粉磨設(shè)備、篩分設(shè)備、洗選設(shè)備及焙燒設(shè)備等七大類2 。礦山機(jī)械為重機(jī)裝備，是為基礎(chǔ)原材料工業(yè)服務(wù)的，是我國機(jī)械工業(yè)中的一個(gè)重要分支。長期以來，礦山機(jī)械在開發(fā)我國礦業(yè)資源、促進(jìn)礦業(yè)經(jīng)濟(jì)發(fā)展、實(shí)現(xiàn)礦山生產(chǎn)現(xiàn)代化的進(jìn)程中起著十分重要、不可替代的支撐作用。而礦業(yè)資源的開發(fā)、利用主要是通過礦山機(jī)械來實(shí)現(xiàn)、完成的。因此，礦山機(jī)械的先進(jìn)性與現(xiàn)代化，在一定程度上反映了一個(gè)國家的工業(yè)化水平?？梢?，礦山機(jī)械對于國民經(jīng)濟(jì)的發(fā)展有著特別重要的地位和作用3 。篩分設(shè)備在礦山機(jī)械中占有重要地位，它的發(fā)展不僅僅代表著中國礦山機(jī)械的發(fā)展，它還代表著中國國力的增強(qiáng)，著一個(gè)國家的基礎(chǔ)工業(yè)的實(shí)力和工業(yè)科技水平4。3、國內(nèi)外現(xiàn)狀目前國內(nèi)篩機(jī)產(chǎn)品種類有圓振動篩、直線振動篩、橢圓振動篩、高頻振動篩、弧形篩、等厚篩、概率篩、冷礦篩、熱礦篩、節(jié)肢篩等，旋振篩和各種振動給料機(jī)械，多達(dá)50多個(gè)系列近1000種規(guī)格，產(chǎn)品已在冶金、礦山、煤炭、輕工等許多行業(yè)得到廣泛的應(yīng)用，基本上滿足了國內(nèi)國民經(jīng)濟(jì)建設(shè)的需要5。據(jù)2002年行業(yè)調(diào)查了解，全國篩分機(jī)械制造企業(yè)已多達(dá)300余家，從所有制來看，除國營、集體、股份制外，還有外資和合資企業(yè)，特別是股份制、民營企業(yè)發(fā)展很快。全國篩分機(jī)械市場年產(chǎn)值約為5億元左右，今年又有大的增長，年產(chǎn)值超過1500萬元以上的企業(yè)有10余家6 。由于我國東部經(jīng)濟(jì)發(fā)展較快，篩分機(jī)械制造企業(yè)也主要分布在東北、華北、華東和中南地區(qū)，尤其是鞍山新鄉(xiāng)地區(qū)，這兩個(gè)地區(qū)的篩分機(jī)械產(chǎn)值約占全國總產(chǎn)值的50左右，可是在西部地區(qū)，還沒有一家像樣的篩分設(shè)備制造企業(yè)。我國篩分設(shè)備制造企業(yè)雖然很多，但是真正具備實(shí)力的很少。目前全國具有獨(dú)立研究開發(fā)新產(chǎn)品能力的企業(yè)不多，大約有34家，每年能創(chuàng)新開發(fā)幾個(gè)新產(chǎn)品，而大多數(shù)企業(yè)仍是生產(chǎn)常規(guī)較為陳舊的產(chǎn)品。在產(chǎn)品設(shè)計(jì)和制造水平上，全國大約只有45家企業(yè)的機(jī)械裝備和工藝水平真正具備制造較大篩分機(jī)械的能力7。德國申克和K H D公司是國際著名的篩分機(jī)械制造企業(yè)，他們的新產(chǎn)品開發(fā)是和工程設(shè)計(jì)同時(shí)進(jìn)行的：首先要對被篩物料的物理、化學(xué)性質(zhì)以及在工藝流程中所需達(dá)到的要求進(jìn)行分析，選擇合理的技術(shù)參數(shù)、進(jìn)行模擬樣機(jī)試制、進(jìn)行必要的設(shè)計(jì)計(jì)算、工作圖設(shè)計(jì)、產(chǎn)品試制、檢驗(yàn)、服務(wù)、工藝試驗(yàn)、跟蹤服務(wù)、產(chǎn)品改進(jìn)設(shè)計(jì)、定型等一系列程序，最后實(shí)現(xiàn)交鑰匙工程8。4、發(fā)展方向(1)深入研究新的篩分理論和技術(shù)2002年，中國礦大機(jī)械廠為解決大型振動篩強(qiáng)度問題，提出了超靜定網(wǎng)梁結(jié)構(gòu)理論并使用成功，獲得國家專利。最近，新鄉(xiāng)威猛集團(tuán)將12臺2m3m的節(jié)肢篩組合在一起，形成了目前國內(nèi)最大的7.2m振動篩，用于選煤系統(tǒng)的分級和脫水、脫介，效果很好。同樣，中國科技大學(xué)為鐵法礦務(wù)局曉青礦研制了篩框不動、篩網(wǎng)振動的大型振動篩9。(2)引入現(xiàn)代化設(shè)計(jì)手段，采用新材料、新技術(shù)、新工藝對現(xiàn)有的篩分機(jī)械進(jìn)行運(yùn)動分析和結(jié)構(gòu)改進(jìn)，引入現(xiàn)代化設(shè)計(jì)手段，采用優(yōu)化設(shè)計(jì)，計(jì)算機(jī)輔助設(shè)計(jì)，用計(jì)算機(jī)對篩分結(jié)構(gòu)強(qiáng)度進(jìn)行計(jì)算，提高設(shè)計(jì)的可靠性；建立振動篩試驗(yàn)臺，對篩機(jī)產(chǎn)品進(jìn)行檢測。全面推廣使用新材料、新技術(shù)新工藝。對振動機(jī)械用的鋼材、軸承、彈簧、篩網(wǎng)進(jìn)行專門研究，篩面應(yīng)從金屬篩網(wǎng)向非金屬篩網(wǎng)發(fā)展，應(yīng)用橡膠篩板、聚氨酯篩網(wǎng)、彈性桿篩面；支承元件應(yīng)采用橡膠彈簧和復(fù)合彈簧；推廣環(huán)槽鉚釘和高強(qiáng)度螺栓聯(lián)接10。(3)向標(biāo)準(zhǔn)化、系列化、通用化發(fā)展提高三化水平，這是便于設(shè)計(jì)、組織專業(yè)生產(chǎn)和保證質(zhì)量的途徑。有些零部件如標(biāo)準(zhǔn)化、通用化了，組織專業(yè)化生產(chǎn)，可大大降低成本，提高企業(yè)效益。4.5強(qiáng)化篩機(jī)技術(shù)參數(shù)根據(jù)不同用途研制新篩機(jī)。發(fā)展大型、重型、超重型篩分設(shè)備，篩機(jī)振動篩強(qiáng)度可達(dá)5.4以上，篩分面積向27m2以上發(fā)展(德國一家篩子技術(shù)公司曾生產(chǎn)5mllm、篩分面積達(dá)55m的篩機(jī))，提高篩機(jī)的處理能力和承載能力11。(4)不斷擴(kuò)大篩機(jī)應(yīng)用領(lǐng)域根據(jù)不同用途，研制出各種不同型式的篩機(jī)，目前，國內(nèi)對于細(xì)和超細(xì)物料的分級，含水分7-13粘性物料的分級還存在問題。重機(jī)網(wǎng)曾聯(lián)系國內(nèi)外需要100目以下，生產(chǎn)能力為15t/h的細(xì)篩，國內(nèi)就沒廠家能接，我們應(yīng)發(fā)展特殊用途篩分設(shè)備，滿足國民經(jīng)濟(jì)建設(shè)發(fā)展的需要，并擔(dān)當(dāng)對外出口的任務(wù)12。二、課題主要研究內(nèi)容1、振動篩分的基本原理直線振動篩(直線篩)工作原理：振動篩工作時(shí)，兩電機(jī)同步反向放置使激振器產(chǎn)生反向激振力，迫使篩體帶動篩網(wǎng)做縱向運(yùn)動，使其上的物料受激振力而周期性向前拋出一個(gè)射程，從而完成物料篩分作業(yè)13。2、振動篩總體方案的比較與確定經(jīng)過仔細(xì)的研究后選擇下列性能參數(shù)的方案：篩面尺寸1000X2000，篩面層數(shù)1，網(wǎng)孔尺寸2-200，產(chǎn)量21t/h，能耗0.74kw，振幅2mm。3、主要零件選擇方案的比較與確定主要螺栓、防撞擊墊片等均采用國家標(biāo)準(zhǔn)，以減少制作成本。三、主要問題及解決方案1、振動篩降噪措施緊固振動篩上的所有部件，特別是需要經(jīng)常更換的篩板，避免由于個(gè)別部件的松動而產(chǎn)生的額外振動；將沖孔鋼篩板更換為彈性模量小、沖擊噪聲低的聚氨酯篩板或者橡膠篩板；在篩箱的側(cè)板、入料給料口、排料口和接料底盤內(nèi)加貼橡膠板，這樣可以有效地抑制側(cè)板的高頻振動，減少輻射噪聲；采用柔性輻板齒輪來代替鋼齒輪，即在齒輪的輻板上利用橡膠彈性體傳遞扭矩，吸收齒輪嚙入、嚙出所造成的振動；用橡膠彈簧替代鋼制彈簧，以減少沖擊；在激振器的體外加裝軟式隔聲罩；對軸承的內(nèi)外套之間加以阻尼處理，軸承的滾動體可以制作成空心滾動體或者在空心滾動體的內(nèi)部加入阻尼材料，這樣能夠減小軸承的振動和降低軸承的噪聲14。2、常見故障及處理措施(1)篩分時(shí)篩子不下料或下料不暢一是給煤溜槽與篩面之間有落差太小，應(yīng)是其落差在400500mm之間。二是新更換或新安裝的振動篩實(shí)際處理量達(dá)不到理論設(shè)計(jì)時(shí)的處理量，即無法滿足生產(chǎn)要求，這時(shí)應(yīng)提高篩子角度、加大激振力，如果還無法滿足要求，就需要對篩面進(jìn)行改造：將入料端的篩孔加大。還要注意的一點(diǎn)是給料槽寬度要適中，如果過窄，物料則不能均勻地分布于篩面的寬度方向上，篩子的篩分面積也不能合理有效利用，篩分效果將會受到影響15。(2)篩框斷裂根據(jù)斷裂力學(xué)的原理，篩框顫抖容易發(fā)生斷裂，所以解決該問題的最佳辦法就是加厚側(cè)板，或者對激振器附近的側(cè)板局部增加附板以增強(qiáng)整個(gè)篩體的剛性，這樣篩框就不容易發(fā)顫和斷裂了16。(3)軸承過熱第一種最常見的原因是由于軸承徑向游隙太小。由于振動篩上的軸承承載的負(fù)荷較大，頻率較高，且載荷一直是變動的，所以軸承必須采用大游隙。如果使用的是普通游隙的軸承，就必須將軸承外圈再次磨削，使之成為大游隙。再者就是軸承壓蓋頂?shù)锰o，也會造成這種現(xiàn)象。壓蓋與軸承外圍之間必須有一定間隙，以保證軸承正常的散熱和一定的軸向串動。該間隙可以通過端蓋和軸承座之間的密封墊來進(jìn)行調(diào)整17。3、篩分的分級(根據(jù)篩分的目的)(1)獨(dú)立篩分其目的是得到適合于用戶要求的最終產(chǎn)品。例如，在黑色冶金工業(yè)中，常把含鐵較高的富鐵礦篩分成不同的粒級，合格的大塊鐵礦石進(jìn)入高爐冶煉，粉礦則經(jīng)團(tuán)礦或燒結(jié)制塊入爐18。(2)輔助篩分這種篩分主要用在選礦廠的破碎作業(yè)中，對破碎作業(yè)起輔助作用。一般又有預(yù)先篩分和檢查篩分之別。預(yù)先篩分是指礦石進(jìn)入破碎機(jī)前進(jìn)行的篩分，用篩子從礦石中分出對于該破碎機(jī)而言已經(jīng)是合格的部分，如粗碎機(jī)前安裝的格條篩，篩分其篩下產(chǎn)品。這樣就可以減少進(jìn)入破碎機(jī)的礦石量，可提高破碎機(jī)的產(chǎn)量。(3)準(zhǔn)備篩分其目的是為下一作業(yè)做準(zhǔn)備。如重選廠在跳汰前要把物料進(jìn)行篩分分級，把粗、中、細(xì)不同的產(chǎn)物進(jìn)行分級淘汰19。(4)選擇篩分如果物料中有用成分在各個(gè)粒級的分布差別很大，則可以經(jīng)篩分分級得到質(zhì)量不同的粒級，把低質(zhì)量的粒級篩除，從而相應(yīng)提高了物料的品位，有時(shí)又把這種篩分叫篩選。(5)脫水篩分篩分的目的是脫除物料的水分，一般在洗煤廠比較常見。此外，物料含水含泥較高時(shí)，也用篩分進(jìn)行脫泥20。四、日程安排第4周：查找畢業(yè)設(shè)計(jì)資料及外文翻譯資料并綜述第5周：外文翻譯第6周：完成開題報(bào)告第7周：總體方案設(shè)計(jì)第8周：運(yùn)動學(xué)與動力學(xué)參數(shù)的選擇與計(jì)算第910周：裝配圖設(shè)計(jì)第11周：完成裝配圖第1213周：零部件設(shè)計(jì)與修改第1415周：撰寫并完善畢業(yè)設(shè)計(jì)說明書第16周：準(zhǔn)備答辯第17周：答辯五、參考文獻(xiàn)：1劉樹莢，韓清凱，聞邦椿.新型振動破碎機(jī)非線性動力學(xué)分析J .振動與沖擊，2000(3) 2劉樹英.動破碎機(jī)的發(fā)展與應(yīng)用.振動利用與控制工程的若干理論及應(yīng)用D. 長春吉林科學(xué)技術(shù)出版社，20003李以農(nóng)，劉樹英，聞邦椿.慣性振動圓錐破碎機(jī)新工藝及動力分析M.礦山機(jī)械，2001(2)4 Wenying li,Shibo xiong.Dynamic Anlysis of Large Vibrating ScreenM. Beijing: Mechanical industry publishing house，19895彭運(yùn)軍譯.圓錐破碎機(jī)J. 選礦機(jī)械，1992(2)6張世禮.PZ-450振動圓錐破碎機(jī)實(shí)驗(yàn)研究J礦山機(jī)械，1997(2)7Hua Zhao. Journal of China University of Mining and Techonolgy M. Mining machinery. 1997(2)8鎮(zhèn)江農(nóng)業(yè)機(jī)械學(xué)院.農(nóng)業(yè)機(jī)械制造工藝學(xué)M.北京：中國農(nóng)業(yè)機(jī)械出版社，19819聞邦椿.振動給料機(jī)，振動輸送機(jī)與振動篩的設(shè)計(jì)M.北京：化學(xué)工業(yè)出版社，198910聞邦椿、劉樹英.振動機(jī)械的理論與動態(tài)設(shè)計(jì)方法M.北京：機(jī)械工業(yè)出版社，200111Teyn,Jacques.Fatigue failure of deck support on a vibrating screenD.the international joumal of pressure vessels and pipingM.volume:61,issue:2-3,1995,315-327 12趙國珍等.鉆井振動篩的工作原理與測試技術(shù)D.北京：石油工業(yè)出版社，198413吳佳常.機(jī)械制造工藝學(xué)M.北京：中國標(biāo)準(zhǔn)出版社，199214Li Meng. Journal of Coal Science and EngineeringM.et,199815柳連舜、霍光庶.譯鋁生產(chǎn)機(jī)械化D.中國有色金屬工業(yè)總公司輕金屬編輯部199116 張國柱編譯.慣性圓錐破碎機(jī)結(jié)構(gòu)探討J.礦山機(jī)械，1992(6)17 任德樹.粉碎篩分原理與設(shè)備M.北京；冶金工業(yè)出版社，198418 陳懋圻.機(jī)械制造工藝學(xué)M.沈陽：遼寧科學(xué)技術(shù)出版社，198619 李留全.KID型慣性圓錐破碎機(jī)用于金剛石礦物處理J.礦山機(jī)械，199520Andersen.E.Y. Pedersen,Structural Monitoring of the Great Belt East BridgeA.Proceedings of the Thied symposium on Steai Crossing,Edited by Jon KrokedorgBalkemaM.et,1994,54-62