摘要: 焊接装备就是在焊接生产中与焊接工序相配合，有利于实现焊接生产机械化、自动化，有利于提高装配焊接质量，促使焊接生产过程加速进行的各种辅助装置和设备。焊接工装在焊接机械化中也扮演着重要的角色，采用工装夹具，工件定位迅速，装夹方便，省力，减轻了焊件装配定位和夹紧时的繁重体力劳动；焊件的翻转可以实现机械化，变位迅速，使焊接条件较差的空间位置焊缝变为焊接条件较好的平焊位置焊缝，劳动条件改善，同时也有利于提高焊缝的质量。在装配定位焊件时，如果不使用工装夹具，即使焊接组合件由两三个零件组成的，欲保证各零件精确的相对位置也是很难的。同时，在焊接过程中，焊接件一般会由于受热不均等原因而发生焊接变形，尤其是复杂的焊接结构，其变形有时会无法消除，这样就会影响以后的装配工作。采用工装夹具，不仅可以保证焊接时工件间的相对正确位置，而且可以防止和减少工件的焊接变形。批量生产的时候，这种优点就更加明显，可以稳定焊接件的质量，减少次品的产生。焊接滚轮架是借助主动滚轮与焊件之间的摩接力带动焊接旋转的变位机械。焊接滚轮架主要用于筒形焊件的装配与焊接。焊接滚轮架按结构形式分为两类：第一类是长轴式滚轮架。第二类是组合式滚轮架。本文主要对组合式12T焊接滚轮架进行设计，并对轴、键等主要构件进行了校核。结果表明各主要部件符合要求。该滚轮架结构简单，使用方便灵活，对焊件的适应性很强。设计中充分的考虑了滚轮架的合理性和经济性等因素。

关键字：焊接工装夹具滚轮架

Abstract : Welding equipment is a machine which is used in welding production and welding processes, and it is conducive to welding production mechanization and automation, to improving assembly welding-quality. Then it could prompte to speed up the process of welding production of the various assistive devices and equipment. Welding fixtures also play an important role in Mechanized welding, with fixture, positioning quickly, easy clamping, effort, reduce the weldment assembly positioning and the clamping the heavy manual labor; flip the weldments can be mechanized, rapid deflection, and make the spatial location weld of poor conditions into a better position weld , improved working conditions, at the same time it help to improve the quality of the weld. When in the assembly weldments of positioning, if you do not use the fixture, even if the welding assembly formed by the two or three parts, to ensure the accuracy of the relative position of each part is very difficult. At the same time, in the welding process, the Welding parts generally would occurred welding deformation as uneven heating and other reasons, especially with the welded structures was complex, sometimes its deformation can not be eliminated, this will affect the future work of assembly. With fixture, not only can ensure the correct relative position in welding between the workpiece, but also can prevent and reduce the welding deformation of the workpiece. When in the mass production, this advantage become more apparent, can stabilize the quality of welded parts, reduce the production of defective. Welding roller standing by structural form is divided into two categories : the first category is long axis-wheel frame. the second category is modular roller frame. In this paper, twelve pairs of modular T-welded wheel for the design, as well as axial, bond and other main component of checking. The results showed that the main components to meet the requirements. The roller frame structure is simple, flexible, adaptive welded pieces of a strong, which is the most widely used form of the structure. And it could be fully considered the roller frame reasonable and economic, and other factors.

Keyword: weld frock clamp turning rolls

1 引言1

2 焊接机械设备2

2.1 焊接机械装备2

2.1.1焊接机械设备的分类2

2.1.2焊接机械装备对焊接产生的作用3

2.2 焊接自动化3

2.3 焊接工装夹具4

2.3.1焊接工装夹具的特点5

2.3.2焊接工装夹具的分类6

2.3.3对焊接工装夹具的设计要求6

2.3.4焊件在焊接工装夹具中的定位方法7

2.4 焊机变位机械8

2.4.1焊接变位机械的分类8

2.4.2焊接变位机械应具备的性能9

2.5 几种焊接设备的具体介绍9

2.5.1焊接变位机9

2.5.2焊接翻转机11

2.5.3焊接操作机12

2.5.4焊接滚轮架13

2.5.5关于滚轮架轴向窜动的问题15

3 方案的选择与确定17

3.1组合式滚轮架的特点17

3.2滚轮驱动方案18

3.3减速器的选择19

3.4联轴器的选用20

3.5滚轮架滚轮的设计21

3.6轴的设计22

3.7轴承的选用23

3.8轴承端盖的设计24

3.9丝杠的设计25

3.10键的设计26

3.11机架的设计26

3.12表面粗糙度27

4 计算与校核28

4.1 焊接滚轮架的设计计算28

4.1.1驱动圆周力与支反力的分析及中心角的确定28

4.1.2焊接滚轮架的受力31

4.1.3滚轮架支反力的计算32

4.2 电动机的选定35

4.3 轴的校核35

4.4 滚轮处键的校核37

4.5 轴承寿命计算37

4.6 轴承的强度计算38

结论40

致谢41

参考文献42

附录A43

1.引言

焊接是一种制造技术，它是适应工业发展的需要，以现代工业为基础发展起来的，并且直接服务于机械制造工业。焊接技术的发展与制造工业的需要紧密相关，一般工业先进国家，钢产量的50%左右需采用焊接工艺才能形成产品，在石油化工、矿山冶金、金属结构、起重运输、水陆交通、航天航空、桥梁建筑、电力能源等机械设备制造部门，焊接都有着广泛的应用。许多设备中的大型结构，几乎都是焊接结构。现在，随着科学技术的进步，生产规模的日益扩大，焊接结构正朝着超大型，高容量，高参数，耐磨，耐低温，耐动载的方向发展，这就不仅需要为焊接生产提供质量更高，性能更好的各种焊机，焊接材料和焊接工艺，而且要求提供各种性能优异的焊接工装设备，使焊接生产实现机械化和自动化，减少人为因素干扰，达到保证和稳定焊接质量，改善焊工劳动条件，提高生产率，促进文明生产的目的。但是，焊接生产是综合性生产，在焊接制造过程中，除了焊接工序本身外，前后还有很多工序的配合，如备料、输送、装配、检验、校正等工序。因此，焊接生产的机械化自动化不仅仅局限于焊接工序本身，而且包括了与焊接工序相衔接的上下各工序的机械化，自动化。只有各工序实现了机械化，自动化，才能实现焊接生产的综合机械化，自动化。

滚轮架主要用于筒形焊件的装配与焊接。若对主、从动滚轮的高度作适当调整，也可进行锥体、分段不等径回转体的装配与焊接。对于一些非圆长形焊件，若将其装卡在特制的环形卡箍内，也可在焊接滚轮架上进行装焊作业。焊接滚轮架还可配合手工焊或作为检测、装配圆筒体工件的设备。焊接滚轮架的使用能大大提高焊缝质量，减轻劳动强度，提高工作效率。

本毕业设计根据任务书的要求，通过构思建立滚轮架三维实体模型，分析模型的优越性和适用度选择此种机构。设计滚轮机架各部零件，分析校核零件，检查是否有错，按顺序正确组装，然后投入使用。从而，完成了毕业设计任务书所规定的设计内容。

限于个人水平，此次设计难免存在不足之处，敬请老师指教。

2.焊接机械设备

2.1焊接机械装备

焊接机械装备就是在焊接生产中与焊接工序相配合，有利于实现焊接生产机械化，自动化，有利于提高装配—焊接质量，促使焊接生产过程加速进行的各种辅助装置和设备。这里称之为辅助装置和设备是为了与焊机相区别。焊机是焊接过程中的核心装备，它包括焊接电源，焊接控制箱，焊接机头等，有自己的独立系统，不属于焊接机械装备的范畴。而焊接机械装备相对焊机处于辅助的地位，是配合焊机进行焊接生产的装置和设备。它包括的范围较广，按用途分，主要有焊接工装夹具、焊接变位机械和焊接输送机械三个方面，其次还有导电装置、焊剂输送与回收装置、坡口准备及焊缝清理精整装置等。他们又是焊接机械装备的从属装置。

从使用范围来分，焊接机械装备又分为通用和专用两大类。

通用焊接机械装备通用性强、适应性广，整台机械能适应产品结构的变化重复使用。它们可以组合在一起使用，也可以组装在焊接生产线上，成为焊接生产线的一个组成部分。由于这种装备通用性强，所以机械化、自动化水平不是很高，主要满足多品种、小批量焊接生产的需要。

专用焊接机械装备是为了适应单品种、大批量焊接生产的需要专门设计制造的。这种装备专业性强、生产率高、控制系统先进，能很好地满足产品结构、装焊工艺、生产批量的要求。例如：专用焊接工装夹具、专用焊接机床就属于这类装备。

2.1.1焊接机械设备的分类

焊接机械装备可分为四大类：1.焊接工装夹具2.焊接变位机械3.焊接输送机械4.其他从属装置。其中：

（1）焊接工装夹具（按动力源分类）可分为：手动夹具气动夹具液压夹具磁力夹具电动夹具真空夹具混合式夹具。

（2）焊接变位机械可分为：焊工变位机械焊机变位机械焊件变位机械。

其中焊件变位机械可分为：焊接变位机焊接回转台焊接翻转机焊接滚轮架

（3）焊件输送机械可分为：上料装置配料装置卸料装置传送装置各种专用吊具。

（4）其他从属装置可分为：导电装置焊剂输送与回收装置焊丝清理及盘丝装置埋弧焊焊剂垫等。

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内容简介：: Jounal of matenals processing technology 63 (1997) 881-886ExperimentExperimentExperimentExperiment andandandand studystudystudystudy intointointointo thethethethe axialaxialaxialaxial driftingdriftingdriftingdrifting ofofofof thethethethe cylindercylindercylindercylinderofofofof a a a a weldingweldingweldingwelding rollerbedrollerbedrollerbedrollerbedFenggang shen ,xide pan ,jin xueWeldingresearchinstiute,xianjiaotonguniversity.Xian.shaanxiprovince710049.P.R.chinaAbstractThe basic theory of the axial drifting of the cylinder of a welding roller bed is introduced in thepaper,and at the same time experiment and study on the mechanism of the axial drifting of thecylinder have been done on an experimental model of the welding roller bed . It is shown that themain cause of the axial drifting of the cylinder lies in the existence of a spiral angle between thecylinder and the cylinder and the roller . therelative axial motions between the roller and thecylinder are compose of spiral motion,elastic sliding and frictional sliding. The theory ofcompatible motion and non-compatible motion is put forward for the axial motions of thecylinder .the relative axial motions of the cylinder . The relative axial motion between the rollersand the cylinder is coordinated by elastic sliding and frictional sliding between themKeywords: welding roller bed; cylinder ; roller ; axial motion ; spiral angle1IntroductionIn welding production, the assembly and circular seam welding of rotary workpieces, such as aboiler, apetrochemical pressure vessel andso on,are conducted on ;a weldingrollerbed.When rotating On a welding roller bed. The cylinde will inevitably produce axial drifting due tomanufacturing, assembling tolerance of the welding roller bed and the cylinders surfaceirregularity (divergiugfrom anidealrotaryworkpiece),thusthe weldingproceduremay not be carried out successfully. It is necessary,therefore,to study the mechanismoftheaxialdriftingofthe cylinderto solve the problem of the axial driftingofthecylinder in circumferential welding. The results of the research will benefit the studyinganddesigning of antidrifting welding rollerbed. especially the analysis of the applied forces onthebed, and lead to determining the manufacturing and assemblingtoleranceofthebed,andproviding the basis of theory for the mechanical adjusting mode to avoid axialdrifting,theadjusting mode of closed circuitin the controlcircuit, and the selection oftheadjustingvalue.2.Theoretical analysis2.1. Welding roller bed and cylinderA welding roller bed is generally composed of four rollers. Driven by thedriving roller, the cylinder makes a rotary uniform motion arounditsaxis(showninFig.I), duringwhichthecircumferentialweldingprocedureis carriedout InFig.1,ais the central angle, S is the supporting distance, Lis the spanof theroller.and V, is the circular linear velocity ofthecylinder, alsonamed the welding velocity2.Theaxisofthecylinderwillbenotparallelto thatofa rolleriftherollerisdeflectedbyacertainanglefromthe dealposition,orifthecentersofthefourrollersliein theverticesofasimplequadrilateral,orifthecentersof thefourrollersarenotonthesameplane,orifthecircu- larityofthecylinderisirregularbecauseofdeviationin manufacturingandassembling.Thus.thecylinderwill nevitablymovealongitsaxiswhenrotatingonabed thecontactofthe cylinderanda rollercanbecansidered as pointcontactifcytindersaxisandrollersaxisdonot lieinthesameplane.SupposePisthepointofcontact. thecylindersnormalplaneAisdefinedbytheplaneon whicharethecylindersaxisandgeneratrix nacrossthe pointoftangencyon thecylinder(shownin fig2) makea cylinderstangent planeBacrosspointP.Thus,planeA isverticaltoplaneB. lcisa cylinders tangent across PandliesinplaneB.Iristherollerstangentacross thesamepointP,andliesinplaneBalso.Ingeneral, isdefinedastheaxialdeviationanglebetweentherol!ers axisandthecylindersaxis;isdefinedasthespiral anglebetweengeneratrixnandm. aprojectiveline obtainedbyprojectingtherollersgeneratrixmacrosspointponplaneBandisdefinedastheprojective anglebetweennandm, a projective line obtained byprojectingmonplaneA.Fig.3indicatesthattherela- tionshipamongstthethreeanglesis tan = tan2 -tan 2InFig.3,SB,S andS,arecalledthespiraldisplace- mentvector,theaxialdeviationdisplacementvectorand theprojectivedisplacementvectorrespectively.theirrelationshipbeing:Fig.2 Geometricrelationshipbetween the cylinder and anindividualrollerFig.3 Relationshipbetweentheanglevectorandthedisplacementvector2.2.2 relative axial motions relationship(1)spiral motion2.Fig.4 ComponentofaxialvelocityBecausetherollersaxisisnotparalleltothecylin- derscentralline,thereisa spiralanglebetweenVr,.and Vc,onthepointofcontact(showninFig.2).Whenthe rollerandcylinderrotatesynchronisticallyaroundtheir ownaxes,drivenbytangentialfrictionalforce.aspiral effectwilloccurbecauseofthedifferentlinearvelocity directionbetweentherollerandthecylinderatpointP ofcontactThecylinderhasacomponentofaxialvelocity,whereVcisthecircularlinearvelocityofthecylinder.is thecylindersaxialcomponentvelociryexertedbysingleroller,andjcanbe1.2,3,4,representingthefourrollers,respectively.(2)ElasticslidingBecauseoftheexistenceofaspiralangle,anaxial forceFajactsoncylinder.Whentheforceis lessthanthe maximumaxialfrictionalforcefNj(where f isthe frictionfactor,andNj isthenormalpressurebetweenasinglerollerandthecylinder),thecylinderwillslideelastically overtherolleralongtheaxialdirection23Thecomponentoftheslidingvelocityis.whereeistheelasticslidingfactorformetallicroller. e=O.OOl0.005.(3)FrictionalslidingWhenFajisgreaterthanthemaximumfrictionalforce fNj,thecylinderwillmakeafrictionalslidingoverthe roller.Theslidingresistanceis fNj3.ThecomponentofthefrictionalslidingvelocityonCylinderisVajthe magnitudeanddirectionofwhichcanbedeterminedby theuniversalrelationshipbetweenthecylinderandthefourrollersFrictionalslidingwillleadtothewearandtearofthesurfaceofthecylinderandtherollers.which is unexpectedinweldingproductionWhenthecylinderdrifts,abovethreekindsofmotiondonotoccursimultaneouslyIhereforc.theaxialdrifting velocityofthecylinderisnotthealgebraicsumofthethreecomponentsofvelocityInthecaseofelasticsliding,the axialvelocityis.2.3 axial motion of the cylinder on a welding roller bed2.3.1Axialcompatible motionUnderidealconditions,whenspiralanglesjbetween thecylinderandthefourrollersareallthesame,thatis:1=2=3=4=thecylinderwillmoveithcompatiblespiralmotion. Twocategoriescanbeclassifiedtoanalyzetheaxialmotionofthecylinder:(I)Whentheredoesnotexistanaxialcomponentdue togravity.thecylindersaxialdriftingvelocityis:Va=Vc * tan(2)Whenthereexistsanaxialcomponent of gravity Gathereexistsan axialforceonthecylinder.Now,theaxial forcesexertedonthefourrollershavethesamedirectionalAnd magnitude, the value being equal to Ga besues the component of spiral vetocity, there existcomponent of elastic on the cylinder the cylinders axial drifting velocity is2.3.2.axial non-compatible motionIngeneral.spiralanglesjbetweenthecylinderand thefourrollersarenotequaltoeachotherinsizeand direction.i .e.thegeometricrelationshipsbetweenthe cylinderandthefourrollersareallinconsistentTherefore,thecomponentsofthecylindersaxialvelocityagainstfourrollers(i.e Vc *taj) arenot identical to each another. The cylinderwillmovewith axial nompatible motionTheaxialvelocitiesofthecylinderagainsathefourrollersshouldbethesamebecausethecylinderisconsideredasarigidbodyasawholeandithasonlyone axial velocity.However.forsomeroller,Vc . tanj and thecylindersrealaxialvelocityarenotlikelytobethesame,soanaxialfrictionalforcealmostcertainlyappearsbetweenthisrollerandthecylinderThefollowingtwo categoriescanbeclassifiedtodiscussthenon-compatible axialmotionofthecylinderaccordingtoIhefrictionalforcesmagnitude:(I)Whentheaxialfrictionalforceserectedbyeach rollerandthecylinderareall less thanthemaximumaxial theactionofthecylinderagainstthefrictionalforcethe action of the cylinder against the rollersproduceselasticslidingTheaxialmotionbetween anindividualrollerandthecylinderiscoordinatedbytheirelasticslidingwhentheaxialvelocityofthecylinderisconstant,the algebraicsumofcylindersaxialforceserectedbyfourrollersshouldbezeroifrheaxialcomponentofgravityis ignored.i.e.andthereislittledifferenceamongstNj,againstthefour rollers,sothattheycanbeapproximatelyregardedas thesame.Thus:accordingtotheabovetwoequations,theaxialdriftingvelocityofthecylinderis.Where0.25Tant represents the intrinsic attributes of the welding. Other bed under thecondition that only the cylinder against all rolls produces elastic sliding this may be called thespiral rate of the cylinders spiral motion(2)Whentheaxialfrictionalforceerectedbysome rollerandthecylinderisgreaterthanthemaximumaxial frictionalforce,frictionalslidingoccursbetweenthe cylinderandthisrollerThen.themaximumaxialforceisactingonthebearingof theroller,itsvaluebeingFfmax=fFNfmaxBecauseof the esistenceofthisfrictionalsliding.the Axial motionbetween anindividual roller and the cylinderisnotcoordinatedbytheirelasticslidingNowtheaxialnon-compatiblemotionofthecylinderisdeterminedbytherelativerelationshipsbetweenthecylinderandthe fourrollers.Itisdifficulttowriteageneralcompatible equationofthecylindersaxialdriftingvelocitybecause thiskindofconditionisverycomplex.Thefollowingisfurtheranalysisanddiscussionoftheproblem Atfirst,foreaseinanalyzingproblem,thespiralangle averageisdefinedasand the relative spiral angle asArrange,1intheorderfrombigtosmllandthenfromposirivetonegative,expressedas(j).then1234Similarly,thenormalforcebetweenthecylinderanda rollercanbeexpressedasN(j).andtheaxialforceasFjfNjIngeneral,theaxialmotionofthecylinderdeterminedbythespiralangleaverage isdefinelasthe compatiblecomponentoftheaxialmotion,isvelocitybeingTheaxialmotionofthecylinderdeterminedbytherelativespiralanglejisdefinedasthenon-compatible componentofaxialmotion,itsvelocitybeingexpressed asVanAnalysisshowsthatVaisdeterminedbythe equilibriumconditionthe four roller axial forceswhenthecylindermovesalongaxialdirectionataconstantvelocity.wherenottakingintoaccountofthefunctionofgravitysaxialcomponent. Supposingthatthecylindermakesanon-compatiblecomponentofaxialmotionwiththemaximumrelativespiralangle(I).itsvelocityisThen the four axial forces can not be in equlibrium .i.eF1-(F2+F3+F4) 0Becausethereislittledifferenceamongstfournormalforces,thefouraxialfarcesarealsodeterminedbynormalforceand thefrictionfactoranyaxialforceundoubtedlybeinglessthanthesumof theotherthreeforces. Otherwise,ifthecylindermakesanon-compatiblecomponent ofaxialmotionwiththeminimumrelativespiralangle(4).its velocityis.Va”=Vc * tan(4)Similarly.fouraxialforcescannot be inequilibriumalso, i.e. :F(l)+ F(2)+ F(3) J- F(4) 0Therefore,thecylindercanonlybeapproximatelyconsideredasmakinganon-compatiblecomponentofaxial motionwiththesecondorthirdrelativespiralangle,i.e.:Inwhatevercaseasexpressedabove.whenthecylinder makeanon-compatiblecomponentofaxialmotion,the tworollers havingagreatervelocityaredrivingrollers, andtheothertworollershavingalesservelocityareresistantrollers,theequilibriumconditionofaxialforces beingoperative,i.e.:F(1)+ F(2)= F(3)+ F(4)Accordingtotheanalysisabove,andbecauseofthe unstabilityoffrictionfactorfthatisaffectedbythefactors ofload,material,conditionofthecontactsurface, andcircumstance,thenon-compatiblecomponentVaof theaxialvelocityofthecylinderis undefined. Whenthecylindermakesanon-compatibleaxialmotion,itsaxialvelocityiscomposedofacompatiblecomponentVa0andanon-compatiblecomponentVani.eVa=Va0+VanVa=Va0+VanThemostoptimaladjustmentoftheaxialmotionisto makethenon-compatiblecomponentassmallaspossible accordingtothestabilityofadjustmentanddecreaseinaxialforce. Nomatterwhetherthecylindermakescompatibleor non-compatiblemotion,supposingthatthecylinderis ideal,itsaxialvelocityisalwaysexistentanddefinable foraparticularbed,itsmagnitudeand directionreflectingthebedsinherentproperty.3.Experiment3.1.Descriphmof expermentTheexperimentalmodelis showninFig5.Experimentsweredonetostudytwofactors:thespiralangleandthe cylinderscircularlinearvelocity,whichaffecttheaxial driftingofthecylinder.Intheexperimentingprocess.the axialdisplacementSaandtheaxialdriftingvelocityVaofthecylinderweremeasuredbythevariationofthetwofactorsdescribedabove.Themeasuringmethodisshown in Fig.5,andiscarriedoutbymeansofbringingan axial displacementsensorintocontactwithoneendofthe cylinder.withthesensorbeingconnectedtoanX-Yrecordertorecordthecylindersaxialdisplacementevery5s.LinearlyregressingtheplotSa-t(texpressestime), theaveragedriftingvelocityVa,ateverydeflectinganglecanbe calculated.Beforeexperimenting.theexperimentalmodelisinitialisedasfollows:first.theheightofthefourrollersisadustedbymeansofa leveltoputthecentersofthefourrollersinthesamehorizontalplane,andatthefourvertexesoftherectangle.thentherollersaredeflectedso thattherotatingcylinderis attherelative equilibrium position.Then.thecylinderdoesnotdriftoveralong time.orperiodicallydriftovera verysmallaxialrange3.2experiment results and discussion3.2.1Effect of spiral angle(I)Fig.6showsthatchangeofVawiththevariationofThetestingconditionis:positiverotalion,Vc=35m/hL=422mm,=60”TheVa-tan4curveshowsthatVaisdirectlyproportionalto tan4when4is relativelysmall(16c ). Theslopeofthelinebeing3. 06 mm/s,Vaisnolongerdireclly proportionaltotan4when4,isgreaterthan6CThecurveisanarchedcurve.i. e . withthe incrementof4,.Va,increases.butwiththeincrementofVagraduallybecomingsmalletBecauseonlyonedrivenroller(rollerNo.4)isdeflected,i.e4 canbechangedwhilsttheothersremain zero,thecylindermakesa non-compatiblemotion. When4isrelativelysmall,Vaissmallalso.Theaxialfrictionalforcesbetweenthecylinderandrollersarelessthanthemaximumaxialfrictionalforce,andthecylinder producesanelasticslidingagainstrollers.Axialmotion betweeneachrollerandthecylinderiscoordinatedbyelasticsliding.thusVais:inthe theoretical curve, theslopeKcan becalculatedbythefollowingequation:K=3.06mm/sintheexperimentalcurve.Thus,in takingaccountoftheexperimentaltolerance,the two slopescanbeconsideredtobeapproximatelyequal.When 4isrelativelylarge,theaxialfrictionalforces betweenthecylinderandtherollersarelargerthanthe maximumaxialfrictionalForce,andcylinderproduces frictionalslidingagainsttherollersBecauseofIheexistenceofslidingfrictionalresistance.Vaisnolongerlincartyincreasedwiththeincrementoftan4Withtheincrementoftan4theincrementofV a;withgraduallybecomesmaller(2)Thefollowingthreeexperimentswerearrangedto studythecylindersnon-compatibleaxialmotionfurther, deflectingpositivelyoneroller.tworollersandthreerollersbythesamespiralangletomeasurethreecurvesbetweenSaandvTheexperimentalresultsareshownin Fig7.Withthe incrementinthenumberofdeflected rollers,Vabecomesgreater.i eVa3 Va2 Va1Whenthenumberofdrivenrollersdeflectedisvaried, thedegreeofthecylindersnon-compatibleaxialmotion willbechanged.Withtheincrementofthenumberof lollersdeflectedbythe samespiralangle.thecompatiblecomponentbecomesgreater,butthenon-compatible componentbecomessmaller.Inotherwords,thecylindersaxialmotionwillbetransformedfromnoncompatiblemotiontocompatiblemotion.Thus,Vabecomesgreateralso,ultimately,beingequaltothecompatibleaxialvelocitydeterminedbythespiralangle Now.thefourrollershavethesamespiralanyle. SothatVais:3.2.2 effect of circular linear velocityDeflectingdrivenrollerNo4toaspiralangleof+2”fromtheequilibriumposition,thecylinderwillsuffer axialdrifting,Fig.8showstheVa-Vccurve,whichlatter indicatesthatVaisdirectlyproportionaltoVc, theslope ofthecurvebeingapproximately0.00708because 4=+2istoosmall,thecylinderdoes not makefrictionalslidingagainsteachroller.Thus,therelativeaxialmotionbetweentherollerandthecylinderis completelycoordinatedbytheirelasticsliding,sothatVaisI. I. I. I.e .VaisdirectlyproportionaltoVeForthetheoretical Curve theslopeK *canbecalculatedbythefollowing equation K”=0.25tan 4=0.25tan2=0.00873 whereK=0.00708mm/sintheexperimentalcurve.Thus, intakingaccountoftheexperimentaltolerance,thetwo slopescanbeconsideredtobeapproximatelyequal.导室.4Conclusions1.Becauseofthedeviationsduetomanufacturingand assembling.thecylinderscentrallineandtherollers axisarenotparallel.i. e,theyarenotinthesame plane,andthereisaspiralangle atthcpointofcontactbetweenthecylinderandtherollerinthecircular linearvelocitydirection.Theexistenceofisthebasicreasonfortheoccurrenceofaxialdrifting.Theeffectof gravityincylindersaxialdirectionisalsoone ofrea

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