皮带驱动故障

2020-03-13©SKFSlide1[Code]SKF[Organisation]BeltDriveProblems皮带驱动故障2020-03-13©SKFSlide2[Code]SKF[Organisation]BeltDrivesOffer皮带驱动的特点Flexibilityindrivedesign驱动设计的灵活性Speedratiovariation速比的可变性Clean,lubricationfreeoperation干净，无需润滑的操作Easeofreplacement更换的简便性Relativelyhighefficiency相对的高效率2020-03-13©SKFSlide3[Code]SKF[Organisation]CommonConstruction一般结构Wrappedbelt梯形皮带Cogbelt齿形皮带2020-03-13©SKFSlide4[Code]SKF[Organisation]BeltDriveProblemTypes皮带驱动故障类型Probably3ofthegreatestfactorsaffectinghowmuchvibrationabelt-drivenmachinewillexperienceare:影响皮带驱动设备振动大小的三个主要因素是：•AlignmentofSheaves皮带轮对中•SheaveConcentricity皮带轮同心度•SheaveConstructionandAttachmentMethod皮带轮结构和安装方法Ifeachofthesefactorsarecarefullyconsidered,thereisnoreasontohaveinherentlyhighvibrationinbelt-drivenmachines.如果能仔细考虑以上三个因素，就能摆脱皮带驱动设备的高振动2020-03-13©SKFSlide5[Code]SKF[Organisation]BeltDrives皮带驱动1.Itisbesttotakeradialmeasurementsinlinewithbeltdirectionasshown最佳方法是沿着皮带方向进行径向测量，如下图所示垂直于皮带张力方向平行于皮带张力方向垂直垂直水平水平2020-03-13©SKFSlide6[Code]SKF[Organisation]BeltDrives皮带驱动2.AdjustableV-beltsheavescreateunduevibrationandprematurebeltandsheavedeterioration.Thesedeviceshaveinherentvibrationproblemssinceitisnotpossibletokeepsheavefacesparallelwithoneanotherwhichallowsbeltstorideupanddowninthegrooveswitheachrevolution.Asaresult,thiscreatesbelttensionvariationwhichgenerateshighvibrationandacceleratesbeltandsheavewear.可调整的V形皮带轮会引起振动过大以及皮带和皮带轮的过早恶化。这类设备有固有的振动问题,因为很难使皮带轮互相平行，使皮带在凹槽内每转一周都会一张一弛。而皮带张力的波动，会导致高振动并加快皮带和皮带轮的磨损2020-03-13©SKFSlide7[Code]SKF[Organisation]BeltDrives皮带驱动3.Anothercriticalfactorinbeltdrivesistheamountofsheaveeccentricity(i.e.,runout).Unfortunately,sheaveswhicharepurchasedforgeneralutilitymachineryalmostalwayshaveinherentlyhigheccentricitymuchgreaterthanthatofothercomponentswhichareusedingeneralrotatingmachinery.皮带驱动中另一个关键因素是皮带轮偏心的多少。用于一般通用设备的皮带轮大多在购买时已经比用于一般旋转机械的其它部件有更高的偏心率。2020-03-13©SKFSlide8[Code]SKF[Organisation]Worn,LooseorMismatchedBelts磨损，松动或不匹配的皮带BeltFreq.=(3.142)(PulleyRPM)(PulleyPitchDia.)/BeltLength皮带频率=(3.142)(皮带轮转速)(皮带轮节圆直径.)/皮带长度0.5*RPM1.Wornbeltdefectsdetectablebyvibrationanalysisincludecracks,broken-offpiecesofbelt,hardandsoftspots,lumpsonbeltfaces,andalsoacrookedbeltwhichhastakenasetdeformedshapeduringpackingandstorage.振动分析可检测出的皮带缺陷，包括开裂，皮带碎裂，皮带硬块和软块，以及在包装和储存过程中发生的皮带弯曲2020-03-13©SKFSlide9[Code]SKF[Organisation]Worn,LooseorMismatchedBelts磨损，松动或不匹配的皮带2.Whentheproblemisawornbelt(s),theywillnormallygenerate3to4multiplesofbeltfrequency.Often,the2Xbeltfrequencypeakmaybedominant;inothercases,thefundamentalbeltfrequencypeakitselfmaynotevenshow.Inaddition,wornbeltssometimesliftthebaselineofthespectrumthroughoutthesubsynchronousfrequencyregion,andjustbeyonddriveranddrivenspeeds.当故障为皮带磨损时，一般产生3到4倍的皮带频率。通常2X皮带频率峰占主导地位；若是其他问题时，基础皮带频率峰值可能不会显现。另外，皮带磨损有时会在次同步频率范围内提升频谱的基线，并超过驱动机和被驱动机转速一点。2020-03-13©SKFSlide10[Code]SKF[Organisation]Worn,LooseorMismatchedBelts磨损，松动或不匹配的皮带3.Beltdefectsusuallyshowhigheramplitudesinthedirectionparalleltobelttension.皮带缺陷通常会在与皮带张力平行的方向上引起更高的振动幅值4.OtherbeltspecificproblemswhichshowupatbeltRPMharmonicsincludebeltwidthvariationswhichcausethebeltstorideupanddownpulleygrooves,creatingvibrationduetobelttensionvariations.其他皮带特有问题包括皮带宽度变化，会表现在皮带转速谐波上，会导致皮带在带轮槽内一松一紧，导致皮带张力波动引起振动5.Aloosecogbeltisindicatedbyhighvibrationatthe#cogsXRPM,and/orhighvibrationatthecogbeltfrequencyitself.齿形皮带松动表现为在带轮齿数XRPM和/或齿形皮带自身频率上产生高振动2020-03-13©SKFSlide11[Code]SKF[Organisation]Worn,LooseorMismatchedBelts磨损，松动或不匹配的皮带6.MultipleV-beltdrivescangeneratehighvibrationintheaxialdirectioniftheyareunequallytensioned.Thiscanresultinexcessivethrustbearingwear.Theseproblemsaresometimessolvedbyreplacingseveralindividualbeltswithonemulti-beltwhichhasbeenmoldedintoonepiece.Iftheseareused,theyplaceevengreaterimportanceoncarefullyaligningthesheaves.多根V形皮带如果每根张力不均匀，会产生高的轴向振动，从而导致推力轴承的过度磨损。这些故障通常用多根一体皮带来替换多根独立皮带的方法来解决。如果使用这种方法，皮带轮对中就具有更大的重要性。7.Worn,looseormismatchedbeltsnormallygeneratehighestvibrationintheradialdirection,particularlyinlinewithbelttension.磨损、松动或不匹配的皮带通常会在径向产生最高振动，尤其是皮带张力方向上。2020-03-13©SKFSlide12[Code]SKF[Organisation]Worn,LooseorMismatchedBelts磨损，松动或不匹配皮带2020-03-13©SKFSlide13[Code]SKF[Organisation]Belt/SheaveMisalignment皮带/皮带轮不对中Misalignedsheavesdisplaythefollowingcharacteristics:皮带轮不对中有以下特征：1.Axialvibrationismostalwaysgeneratedbysheavemisalignmentwhichcanhighlyacceleratetherateofwearofthrustbearings.轴向振动通常是由皮带轮不对中产生的，皮带轮不对中会加快推力轴承的磨损2020-03-13©SKFSlide14[Code]SKF[Organisation]Belt/SheaveMisalignment皮带/皮带轮不对中2.Misalignedsheavesproducehighvibrationat1XRPM,predominatelyintheaxialdirection.DominantvibrationisquiteoftenatdriverRPM,butoccasionallyatdrivenRPM.TheratioofamplitudesofdrivertodrivenRPMdependsexactlyonwherethedataistakenaswellasonrelativemassandframestiffness.不对中皮带轮产生高的1XRPM振动，主要是在轴向方向上。占支配地位的振动通常产生在驱动机转速上，但偶尔也会在被驱动机转速上。驱动机转速与被驱动机转速的幅值之比取决于数据的采集位置以及相对质量和结构的刚度3.Oftenwithsheavemisalignment,thehighestaxialvibrationonthemotorwillbeatfanRPM,whilethehighestaxialwhenmeasuringonthefanwillbeatmotorRPM.However,thisisnotalwaysthecase.皮带轮不对中时，通常电机上最高的轴向振动是在风机转速上，而当测量风机时，最高的轴向振