有關(guān)振動(dòng)篩外文翻譯

景德鎮(zhèn)陶瓷學(xué)院畢業(yè)設(shè)計(jì)（論文）有關(guān)外文翻譯院 系：機(jī)械電子工程學(xué)院專 業(yè)： 機(jī)械設(shè)計(jì)制造及其自動(dòng)化名： 學(xué)號(hào)： 指導(dǎo)教師： 完成時(shí)間：2012-04-15說明1、 將與課題有關(guān)的專業(yè)外文翻譯成中文是畢業(yè)設(shè)計(jì)（論文）中的一個(gè)不可缺少的環(huán)節(jié)。此環(huán)節(jié)是培養(yǎng)學(xué)生閱讀專業(yè)外文和檢驗(yàn)學(xué)生專業(yè)外文閱讀能力的一個(gè)重要環(huán)節(jié)。通過此環(huán)節(jié)進(jìn)一步提高學(xué)生閱讀專業(yè)外文的能力以及使用外文資料為畢業(yè)設(shè)計(jì)服務(wù)，并為今后科研工作打下扎實(shí)的基礎(chǔ)。2、 要求學(xué)生查閱與課題相關(guān)的外文文獻(xiàn)3篇以上作為課題參考文獻(xiàn)，并將其中1篇（不少于3000字）的外文翻譯成中文。中文的排版按后面格式進(jìn)行填寫。外文內(nèi)容是否與課題有關(guān)由指導(dǎo)教師把關(guān)，外文原文附在后面。3、 指導(dǎo)教師應(yīng)將此外文翻譯格式文件電子版拷給所指導(dǎo)的學(xué)生，統(tǒng)一按照此排版格式進(jìn)行填寫，完成后打印出來。4、 請(qǐng)將封面、譯文與外文原文裝訂成冊(cè)。5、 此環(huán)節(jié)在開題后畢業(yè)設(shè)計(jì)完成前完成。6、 指導(dǎo)教師應(yīng)從查閱的外文文獻(xiàn)與課題緊密相關(guān)性、翻譯的準(zhǔn)確性、是否通順以及格式是否規(guī)范等方面去進(jìn)行評(píng)價(jià)。變橢圓軌跡振動(dòng)篩的動(dòng)力學(xué)和篩選特性何小梅，劉楚生機(jī)械和電氣工程學(xué)院，中國(guó)礦業(yè)大學(xué)科技，江蘇省徐州市221116，中國(guó)摘要：根據(jù)恒床厚度的篩選過程振動(dòng)篩理想運(yùn)動(dòng)特征被提出，提出了一個(gè)新的振動(dòng)篩變橢圓跟蹤。準(zhǔn)確的力學(xué)模型建立，根據(jù)所需的結(jié)構(gòu)構(gòu)造運(yùn)動(dòng)特征。應(yīng)用多種學(xué)位自由度振動(dòng)理論、特點(diǎn)，分析振動(dòng)篩的。振動(dòng)篩運(yùn)動(dòng)參數(shù)獲得，它的運(yùn)動(dòng)軌跡有線性的，圓的，橢圓的。振動(dòng)篩的運(yùn)動(dòng)動(dòng)態(tài)方程可通過計(jì)算機(jī)模擬得以有效的解決。屏幕表面五個(gè)特殊的點(diǎn)的技術(shù)參數(shù)，包括振幅，運(yùn)動(dòng)速度和引發(fā)指數(shù)，是通過理論計(jì)算獲得。結(jié)果顯示，新設(shè)計(jì)的振動(dòng)篩的軌跡遵循理想的篩選運(yùn)動(dòng)。篩分效率及處理能力可能因此而有效改進(jìn)。關(guān)鍵字：變橢圓軌跡；篩選過程與常量床厚度；動(dòng)態(tài)模型；運(yùn)動(dòng)特性；篩選特征1介紹篩分操作是一個(gè)重要的煤礦處理組成部分。振動(dòng)篩是最廣泛使用的篩選工具之一。振動(dòng)篩，如直線振動(dòng)篩、圓振動(dòng)篩或橢圓振動(dòng)篩，有一個(gè)簡(jiǎn)單的平移運(yùn)動(dòng)。在篩面上處處運(yùn)動(dòng)保持相同的運(yùn)輸速度和引發(fā)指數(shù)的，從而導(dǎo)致低效率的篩選。充實(shí)的拋擲指數(shù)提高加工能力打破了電機(jī)或降低了工作強(qiáng)度。在本文中，我們報(bào)告的設(shè)計(jì)，一個(gè)新的振動(dòng)篩變運(yùn)動(dòng)的痕跡，原則的基礎(chǔ)上篩選過程固定床厚度不同的部分。振動(dòng)篩穿越不同的橢圓軌跡和由此產(chǎn)生的議案，同意與理想的運(yùn)動(dòng)。因此，屏幕處理能力和效率均可以提高。2振動(dòng)表面的理想運(yùn)動(dòng)和變橢圓軌跡振動(dòng)篩的建議2.1振動(dòng)篩常見的篩選特性振動(dòng)篩通常工作在固定振動(dòng)篩上的物料表面強(qiáng)度。移動(dòng)投擲，滾動(dòng)或滑動(dòng)運(yùn)動(dòng)”。為常見的安檢，物料粒度廣泛分布在進(jìn)料端的能量傳遞。物質(zhì)粒子的振動(dòng)篩嚴(yán)重消退。因此，大量顆粒層只有很短的距離飼料結(jié)束。材料穿透屏幕在第一個(gè)1/4到1/2的屏幕，它影響篩選和降低加工能力的。減少細(xì)粒物質(zhì)導(dǎo)致比粒子的大小接近或大于網(wǎng)格。因此，篩分效率下降驚人。物料粒度同時(shí)統(tǒng)一的，從振動(dòng)源給予物料的能量損失很小。因而物料粒子的振幅和速度增加。這導(dǎo)致了物料的垂直深度在送電端厚，而在放電結(jié)束端薄，進(jìn)而影響了篩分效率和處理能力。常見的篩分特性如圖1.

MateiiallayerFeedSciteMateiiallayerFeedt Scineai理ur也t Scineai理ur也e1aigtliFig.1Screeningcharacteristicsofacommon'vibratingscreenKH1O§巖HP總uanL2.2屏幕表面的理想運(yùn)動(dòng)和實(shí)施方案根據(jù)篩選過程恒床等厚的原則，理想的運(yùn)動(dòng)的屏幕表面的描述如下。3變橢圓軌跡振動(dòng)篩的動(dòng)力學(xué)模型分析我們激振力偏離中心重力，要更改新的運(yùn)動(dòng)模式振動(dòng)篩。剛度矩陣的振動(dòng)隔離春天是根據(jù)這些不是零情況和振動(dòng)系統(tǒng)有多重自由度。小橫搖被忽視的簡(jiǎn)化研究。議案被認(rèn)為是剛性梁的非線性振動(dòng)縱向?qū)ΨQ平面。在每個(gè)點(diǎn)振動(dòng)是一個(gè)組合翻譯的重心和屏幕投球重心。以前的研究被忽視水平彈性勢(shì)力的影響垂直方向振動(dòng)的秋千屏幕[311].準(zhǔn)確的動(dòng)態(tài)模型組成包括耦合的三個(gè)微分方程自由度在垂直、水平和擺動(dòng)方向建議。Fig.2Mathematicalmodelofavdbratingscreen振動(dòng)篩的數(shù)學(xué)模型圖中所示.2。重力澳中心，采取直角坐標(biāo)系的原點(diǎn)在靜態(tài)均衡，按照剛性運(yùn)動(dòng)平面[12].微分方程組廣義坐標(biāo)使用重心坐標(biāo)x、y和秋千赤緯角，。，可以寫成:俗二4&做一乙"么j坯=4血23-.-.（1）幺面項(xiàng)0+A）%_佇棚或右-L^）y-kyw^a（I^+右‘）。k E *其中m是振動(dòng)篩的質(zhì)量；j#轉(zhuǎn)動(dòng)慣量美元相對(duì)于中心重力，澳；x和y的x和y位移方向；x和y在x和y的速度方向；加速x和y在x和你們方向；Ois擺動(dòng)角位移；athe安裝角度；外匯、f橫跨薩楊德河fOthe阻尼系數(shù)在x、yandOdirections；k和kythe剛度系數(shù)的支持沿x和ydirections;a0汀春天激振力的振幅，提供的20=mrs偏心其中r為半徑，m的質(zhì)量偏心塊and^the刺激角頻率；1我和l2每個(gè)之間的距離支持春季和重心，我的距離偏心塊的旋轉(zhuǎn)中心之間重心；而pthe夾角我和x路之間。阻尼力相當(dāng)小，可以忽略。然后，式（1）可以簡(jiǎn)化式（2）。

依+2幻尤=4)COSdVA/y+2ky=/Iqsin血—.i (2)"十乂-佃成^十么)x+kycos6r(Z2—4)一『+kvcoscrf^2+L；)3=-y^/sinf^z-/?)七 ■ ~ _4變橢圓軌跡振動(dòng)篩的運(yùn)動(dòng)和篩選的效果分析4.1個(gè)分析的運(yùn)動(dòng)參數(shù)多自由度振動(dòng)理論用來尋找一個(gè)穩(wěn)定解的強(qiáng)迫振動(dòng),如下：a=XC0$々vTOC\o"1-5"\h\z\y=Ysin句，+匕cos&)t (3)替代參數(shù)在式(3)到(2)式。允許一個(gè)穩(wěn)定的解決方案被發(fā)現(xiàn)。2

mra>mroyX=&=0替代參數(shù)在式(3)到(2)式。允許一個(gè)穩(wěn)定的解決方案被發(fā)現(xiàn)。2

mra>mroyX=…y ，匕=o,2X;-Maf1 .rmro）Zcosp+ycosa（Z^-L^YJ-+A2）-/7?;w^/sin/7+Z;si§ina（A-/7?;w^/sin/7+Z;si§ina（A+L）X/必—佇cosa（4,+A2）假設(shè)一個(gè)點(diǎn)的屏幕坐標(biāo)為D(Dx,Dy).運(yùn)動(dòng)方程如下:%—一r+81）、— 做+（q§in由/+Rcos應(yīng)）I）、=qpsin脈+（X+%=f—8D、-Ygin破一（耳gin攻+&cos攻）Q=）sin電D、cos做（4）-￡cosa>r—Csiiicor=SsinHcos（$，+ +2（SC-EH）",（6）+（￡電+C電）」；/=（￡$+CWT（6）當(dāng)E=S,C=HS時(shí)，D點(diǎn)的軌跡是圓。當(dāng)E2S2+C2H2+2ESCH=當(dāng)E=S,C=HS時(shí)，D點(diǎn)的軌跡是圓。一般來說，（6）式表示方程的橢圓面直角坐標(biāo)系。XOY坐標(biāo)系以Y角速度逆時(shí)針旋轉(zhuǎn)從而給定一個(gè)新的坐標(biāo)系x'ay'。一個(gè)標(biāo)準(zhǔn)的橢圓公式在消除xDyD后可得公式（7）。/= （島+C"-（5-+2/2）cos2v+2（SC-￡7/）sinrcosz+（￡T：+C^）sin2v企= （際+CW）' '成+必）sin3y-2（5C-EH}sinycosy+（喜+C2）cos3y1 2（SC-yarctan —, 2（尸+郡）_（疽+*）從這我們知道有些屏幕上的點(diǎn)移動(dòng)或圓的行中，而其他移動(dòng)橢圓。只要旋轉(zhuǎn)的相對(duì)位置偏心塊的中心和重心正確調(diào)整，變橢圓運(yùn)動(dòng)屏幕將獲得的。這提供了一個(gè)合理的扔指數(shù)和材料傳遞速度和提高篩分效率。

4.2運(yùn)動(dòng)軌跡和篩分效率分析穩(wěn)定振動(dòng)系統(tǒng)解決方案，就振動(dòng)篩而言的，可以給出v=-0.00368cos攻af--0.00382sin破 （8）0=0.00035sin做—0.00038cg脈在振動(dòng)篩上任一點(diǎn)的運(yùn)動(dòng)方程為一"=0.00035Dvsinoot-（0.00368+0.00038Z?）cos做七=（-0.00382-0.00035?）gin血+0.00038。cos做公式（8）表示重心的痕跡近似圓形，水平和垂直方向的振幅在3.5mm和5mm之間。圖3表示如重心的移動(dòng)存在三個(gè)自由度。圖3水平和垂直方向的相位差和擺角的振幅一樣。心)(si)Motioninthejduectinn心)(si)MotioninthejduectinnFig.3Mo^rementofthescreencenterofgravityinthree(leveesoffieedom5結(jié)論1） 新振動(dòng)篩變橢圓根據(jù)原則提出了運(yùn)動(dòng)軌跡常數(shù)床厚度的篩選過程。振動(dòng)篩跟蹤不同的不同點(diǎn)橢圓路徑。運(yùn)動(dòng)規(guī)律也同意配合篩面的理想運(yùn)動(dòng)特性。因此，篩選能力和處理效率會(huì)增加。2） 振動(dòng)的理論運(yùn)動(dòng)學(xué)分析屏幕做是為了研究如何變不同參數(shù)會(huì)影響屏幕的議案。電影抽搐振動(dòng)篩參數(shù)的議案線性跟蹤，獲得圓或橢圓。3）總振動(dòng)篩運(yùn)動(dòng)的痕跡通過計(jì)算機(jī)模擬獲得。篩選技術(shù)參數(shù)，包括振幅，速度和引發(fā)指數(shù)，五個(gè)的特定點(diǎn)沿屏幕表面計(jì)算。這些參數(shù)是與篩分效率。結(jié)果顯示模式設(shè)計(jì)的議案振動(dòng)篩符合理想的篩選議案，設(shè)計(jì)能夠有效提高篩分效率。勵(lì)磁機(jī)軸中心的地位，相對(duì)振動(dòng)篩的重心，是篩選高效的極為重要的。因此，我們可以設(shè)計(jì)一個(gè)振動(dòng)篩具有更高的處理的能力而又不會(huì)增加功耗調(diào)整軸中心的相對(duì)位置。這.。是一個(gè)點(diǎn)，需要進(jìn)一步研究。參考文獻(xiàn)WenBC,LiuFQ.振動(dòng)的理論與應(yīng)用機(jī)器.北京：中國(guó)機(jī)械出版,1982GuQB,ZhangEG.復(fù)雜軌跡振動(dòng)篩研究.1998(1):42-46HaoFY.煤制備手冊(cè)：技術(shù)設(shè)備.北京：中國(guó)煤炭行業(yè)出版社，1993YanF.篩分機(jī)械.北京：中國(guó)煤炭行業(yè)出版社.1995LiuCS,ZhaoYM..篩面上的非線性特性的研究.礦物處理設(shè)備，1999(1):45-48TaoYJ,LuoZF,ZhaoYM..在重力強(qiáng)力分離器使用方面的煤脫硫的實(shí)驗(yàn)研究.中國(guó)礦業(yè)與技術(shù)大學(xué).2006,16(4):399-403ZhangEG.篩分，粉碎，脫水設(shè)備.北京：中國(guó)煤工業(yè)出版社，1991KhouryDL.煤清潔工藝.美國(guó)：諾易斯數(shù)據(jù)公司，1981ShangNX,NaJF.2TYA1842圓振動(dòng)篩.礦業(yè)與加工設(shè)備，1990(2):20-24YeHD.等厚圓篩分及其應(yīng)用.燒結(jié)和碼垛，1999,5(3):30-33WenBC,LiuSY,HeQ.振動(dòng)機(jī)械理論和動(dòng)力學(xué)設(shè)計(jì)方法.北京：中國(guó)機(jī)械出版社，2001WangF,WangH.篩分機(jī)械.北京：中國(guó)機(jī)械出版社，2001NiZH.振動(dòng)力學(xué).西安：西安交通大學(xué)出版社，1989ZhuWB.復(fù)雜運(yùn)動(dòng)軌跡振動(dòng)篩的工作原理和計(jì)算機(jī)仿真.礦業(yè)與加工設(shè)，2004(10):34-36PederM.莫根深系列一一種新型的篩分概念.礦物加工，1996,7(37):311-315WenBC.圓振動(dòng)篩的自動(dòng)同步理論.波士頓：美國(guó)機(jī)械工程協(xié)會(huì)，1987:495-500.Dynamicsandscreeningcharacteristicsof

avibratingscreenwithvariableellipticaltraceHEXiao-mei,LIUChu-shengSchoolofMechanicalandElectricalEngineering,ChinaUniversityofMining&Technology,Xuzhou,Jiangsu221116,ChinaAbstract:theidealmotioncharacteristicsforthevibratingscreenwaspresented,accordingtotheprincipleofscreeningprocesswithconstantbedthickness.Anewvibratingscreenwithvariableellipticaltracewasproposed.Anaccuratemechanicalmodelwasconstructedaccordingtotherequiredstructuralmotionfeatures.Applyingmulti-degree-of-freedomvibrationtheory,characteristicsofthevibratingscreenwasanalyzed.Kinematicsparametersofthevibratingscreenwhichmotiontraceswerelinear,circularorellipticalwereobtained.Thestablesolutionsofthedynamicequationsgavethemotionsofthevibratingscreenbymeansofcomputersimulations.Technologicalparameters,includingamplitude,movementvelocityandthrowingindex,offivespecificpointsalongthescreensurfaceweregainedbytheoreticalcalculation.Theresultsshowthatthetracesofthenewdesignedvibratingscreenfollowtheidealscreeningmotion.Thescreeningefficiencyandprocessingcapacitymaythusbeeffectivelyimproved.Keywords:variableellipticaltrace;screeningprocesswithconstantbedthickness;dynamicmodel;motioncharacteristic;screeningcharacteristicsIntroductionScreeningoperationsareanimportantpartofcoalprocessing.Thevibratingscreenisoneofthemostextensivelyusedscreeningtools.Vibratingscreens,suchaslinearvibratingscreen,circularvibratingscreenorellipticalvibratingscreen,haveasimpletranslationalmotion.Themotionfollowsthesamepatheverywhereonthescreenandsothescreenhasconstanttransportvelocityandthrowingindex,whichleadstolowscreeningefficiency.Augmentingthethrowingindextoimprovebreakstheexcitingmotorsprocessingcapacitylowerstheworking.Inthispaper,wereportonthedesignofanewvibratingscreenwithvariablemotiontracesthatisbasedontheprincipleofscreeningprocesswithconstantbedthickness[3-4].Differentpartsofthevibratingscreentraversedifferentellipticaltracesandtheresultingmotionagreeswellwiththeidealmotion.Thusthescreenprocessingcapacityandefficiencycanbothbeimproved.Idealmotionforascreensurfaceandtheproposalofavibratingscreenwithvariableellipticaltrace2.1ScreeningcharacteristicsofcommonvibratingscreensVibratingscreenscommonlyworkatafixedvibrationintensity.Materialonthescreensurfacemovesbythrowing,rollingorslidingmotions.Forcommonscreeners,materialgranularityiswidelydistributedatthefeedend.Theenergyimpartedtothematerialparticlesfromthevibratingscreenisseverelydissipated.Consequently,alargenumberofparticlesbecomelaminatedonlyashortdistancefromthefeedend.Thematerialpenetratesthescreenwithinthefirst1/4to1/2ofthescreen,whichaffectsscreeningandlowersprocessingcapacity[5].Thedecreaseoffine-grainedmaterialcausestheratioofparticlescloseinsizeto,orlargerthan,themeshtoincrease.Thus,thescreeningefficiencydeclinesdramatically.Thematerialgranularitysimultaneouslybecomesuniformandtheenergyimpartedfromthevibrationstothematerialsufferslittleloss.Hence,theamplitudeandvelocityofthematerialparticlesincrease.ThiscausesthematerialbeddepthatthefeedendtobethickwhileatthedischargeenditisThin.Thiskindofmotionleadstoanasymmetricalpenetrationalongthescreensurface,whichinfluencesthescreeningefficiencyandprocessingcapability[6].CommonscreeningcharacteristicsareshowninFig.1.MateiiallayerFeedt ScineaiMateiiallayerFeedt Scineai理ur也e1aigtliFig.1Screeningcharacteristicsofacommon'vibratingscreenO§巖Hp總uanLSciteaibody/Sci'eaisurface2.2IdealmotionforscreensurfaceandimplementingschemeTheidealmotionforscreensurfaceisdescribedbelow,accordingtotheprincipleofscreeningprocesswithconstantbedthickness.Thefeedendofthescreenhasabiggerthrowingindexandahighermaterialdeliveryvelocity,whichmakesbulkmaterialquicklypenetrateandcausesrapidde-laminating.Earlierlaminationofmaterialincreasestheprobabilityoffine-grainedmaterialpassingthroughthemesh.Thescreenhasanappropriatethrowingindexandalittlehighermaterialdeliveryvelocityinitsmiddlepart.Thisisofbenefitforstabilizingfine-grainedmaterialsandforpenetratinguniformlyalongthescreenlength.Alowerthrowingindexandmaterialdeliveryvelocitynearthedischargeendcausesthematerialtostaylongeronthescreenandencouragesmorecompletepenetrationofthemesh.Twomethodsarecurrentlyusedtoimprovescreeningefficiency[7-8].Thefirstistoaddmaterialtothescreenfrommultiplefeedports.Thisistroublesomeinpracticaluseespeciallyintermsofcontrollingthedistributionofdifferentlygranulatedmaterials.Henceitisrarelyusedinpracticalproduction.Thesecondwayistoadoptnewscreeningequipmentlike,forexample,aconstantthicknessscreen.Themotionofthenewscreensurfacecausesmaterialtomaintainthesame,oranincreased,thickness.Itachievesarathermoreidealmotion.Themainproblemwiththeconstantthicknessscreenisthatitcoversabiggerareaandthatthestructureiscomplicatedandhardtomaintain.Asimplestructurewithgood景德鎮(zhèn)陶瓷學(xué)院本科畢業(yè)設(shè)計(jì)（論文）外文翻譯screeningefficiencyisstillanecessity.Wehavedesignedanewvibrationscreenwithavariableellipticaltracethatisbaseduponanidealscreenmotionforuseinrawcoalclassification.Thesizeofthevibratingscreenis3.6mX7.5m,thefeedgranularityis0to50mmandtheclassificationgranularityis6mm.EllipticallyvibratingscreenscombinethebasicadvantagesofbothcircularandlinearvibratingscreensE910].Thelongaxisoftheellipsedeterminesmaterialdeliveryandtheshortaxisinfluencesmaterialloosening,tobeexact.DynamicsmodelanalysisofvibratingscreenwithvariableellipticaltraceWemadetheexcitingforcedeviatefromthecenterofgravity,tochangethemotionpatternofthenewvibratingscreen.Thestiffnessmatrixofthevibrationisolationspringwasnotzerounderthesecircumstancesandthevibratingsystemhadmultipledegreesoffreedom.Minortransversewaggingwasneglectedtosimplifytheresearch.Themotionwasconsideredtobealinearvibrationofarigidbeaminthelongitudinallysymmetricalplane.Ateachpointthevibrationisacombinationofthetranslationofthecenterofgravityandthescreenpitchingaboutthecenterofgravity.Previousstudiesneglectedtheinfluenceofelasticforcesinthehorizontalandverticaldirectionontheswingofthevibratingscreen[3,11].Anaccuratedynamicmodelconsistingofthreedifferentialequationsthatincludecouplingofdegreesoffreedominthevertical,horizontalandswingdirectionsisproposed.Fig.2MatliematicalmodelofavibratingscreenThemathematicalmodelofthevibratingscreenisshowninFig.2.Thecenterofgravity,istakenastheoriginofarectangularcoordinatesystematstaticequilibrium,inaccordancewithrigidmotionontheplane[12].Simultaneousdifferentialequationsingeneralizedcoordinatesusingcenterofgravitycoordinates,(x,y),andtheswingdeclinationangle,0,maybewrittenas必二4)&仙一無"么H奶二4血河-fvy-2^y...JQ- p)-ffi-?如。0+L)xwhereMisthemassofthevibratingscreen'sthemomentofinertiaofMrelativetothecenterofgravity,O;xandythedisplacementsinthexandy0directionas;xandythevelocitiesinthexandydirections'andytheaccelerationsinthexandydirections;istheswingangulardisplacement;atheinstallationangle;fx,fyondfatherdampingcoefficientsinthex,yanddirections;xkandkthestiffnesscoefficientsofthesupportingspringalongthexandydirections;A0theamplitudeoftheexcitingforce,givenby2A=mr?,whereristheradiusofeccentricitythemassoftheeccentricblockandtheexcitingangularfrequency;L1andL2thedistancesbetweeneachsupportingspringandthecenterofgravity’sthedistancebetweentherotatingcenteroftheeccentricblockandthecenterofgravity;and,Btheincludedanglebetweenthelandxdirections.Thedampingforceisrathersmallandcanbeneglected.ThenEq.(1)canbesimplifiedtoEq.(2).依+2kt.x=4COS*7AMy+2kyy=sinJ0+tsma+Z2)x+kycosa(右-A)-v+coscrt^2+ -一sin(由/一(3)Motionandscreeningeffectanalysisofavibratingscreenwithvariableellipticaltrace4.1AnalysisofthemotionparametersMultipledegree-of-freedomvibrationtheorywasusedtofindastablesolutionfortheforcedvibration[13],asfollows:a=Xcos]y=ysin切+*cos (3)0=sill+aCOSX="…卜。,-/mraflcosp+Arcosa(A-7^)70— ,1 ，由'—X\.costr(4‘+L,2)-/77/TOVsinB+k、sin+L)XJ Jaf一奴cdso(妒+乙')xp=一「+81)、—JVcQg脈+(耳win由「+&cos蟲心1)、=qpsin做+(矛+^2Z?i)cos*/i偵=f—&Dx-Ysincot-(耳sinM+女cos攻)Q=sintty-%D、cos做(4)x『-￡cosa>r—CsiiicoryJ)=Ssino?z+Hcoso>7(U+f］驀+2(SC-E"M+(礦+。電).質(zhì)=(￡5+￡7/尸 (6)WhenE2S2+C2H2+2ESCH=0,thetraceofpointDisaline.WhenE=SandC=H,thetraceofpointDisacircle.Ingeneral.(6)expressestheequationofanellipse.ThexoycoordinatewasrotatedYdegreesanticlockwisetogiveanewsetofx'oy'coordinates.AstandardellipticalequationwasthenobtainedaftereliminatingDDxyinEq.(7).財(cái)+匕一13 /2a b2 g-chV ~ +7/2)cos2v+2(SC-￡7/)sinrcos/+(52+C2)sin2v廿= 3+面 ?(尸+H?)siiry-2(5C-L'/f)sin尸海y+(喜+C”)cos2y1 2(SC-EH)y——aretail —-'2(尸+慶)—(慶+L)Fromthisweknowthatsomepointsonthescreenmoveinalineoracirclewhileothersmoveinanellipse.Aslongastherelativepositionoftherotatingcenteroftheeccentricblockandthecenterofgravityareproperlyadjusted,variableellipticalmotionofthescreenwillbeobtained.Thisprovidesareasonablethrowingindexandmaterialdeliveryvelocityandimprovesscreeningefficiency.4.2AnalysisofmotiontraceandscreeningefficiencyThestablesolutionofavibratingsystem,intermsofthevibratingscreen,canbegivenbyTheequationsofmotionforanypointonthevibratingscreenare才=-0.00368cos做W=-0.00382sin彼 (8)6=0.00035sin破-0.00038coscor/=0.00035/?,sitittV-(0.00368+0.00038P)cosftV七二(—0.00382—O.OOO35Q)sin攻+0.00038Z?,coser?/Eq.(8)showsthatthecenterofgravitytracesanapproximatecircleandthattheamplitudeinthehorizontalandverticaldirectionsisbetween3.5mmand5mm.Fig.3

showshowthecenterofgravitymovesinthreedegreesoffreedom.Fig.3givestheangularphasedifferencebetweenthehorizontalandverticaldirectionsaswellastheamplitudeoftheswingangle.0.0005c-o0005CC.' 12 32 "0.0005c-o0005CC.' 12 32 "心eL']ctici:jftiieangle@Fig.JMjcnpemeiitcfthescreencenterofgravityinthreedegreesoffreedom5ConclusionsAnewvibratingscreenwithvariableellipticalmotiontracewasproposedaccordingtotheprincipleofscreeningprocesswithconstantbedthickness.Differentpointsonthevibratingscreentracedifferentellipticalpaths.Themotionpatternagreeswellwiththeidealmotioncharacteristicforascreeningsurface.Thus,screeningcapacityandprocessefficiencycanbeincreased.Atheoreticalkinematicanalysisofthevibratingscreenwasdonetostudyhowvaryingdifferentparametersaffectsthemotionofthescreen.Kinema-ticsparametersofthevibratingscreenthatmotiontracesarelinear,circularorellipticalareobtained.Motiontracesoftotalvibratingscreenweregainedthroughcomputersimulations.Screeningtechnologicalparameters,includingamplitude,velocityandthrowingindex,offivespecificpointsalongthescreensurfacewerecalculated.Theseparametersarerelatedtoscreeningefficiency.Theresultsshowthatthemotionpatternofthedesignedvibratingscreenconformstoanidealscreeningmotionandthatthedesignisabletoeffectivelyimprovescreeningefficiency.Thepositionoftheexciteraxlecenter,relativetothecenterofgravityofthevibratingscreen,isextremelyimportantforscreeningefficient.Thus,wecandesignavibratingscreenwi