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YAH2460 振动筛 设计

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YAH2460—圆振动筛设计,YAH2460,振动筛,设计

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毕业设计（论文）任务书I、毕业设计(论文)题目：YAH-2460圆振动筛设计 II、毕 业设计(论文)使用的原始资料(数据)及设计技术要求：YAH-2460圆振动筛是用来对矿石进行筛分的设备，它可以减轻体力劳动、提高劳动生产率或在生产过程中进行某些特殊的工艺操作，实现机械化和现代化。1. 物料名称： 矿石2. 入料粒度： 250 mm3有效筛面： 14.4 m24. 筛面倾角： 20 05. 筛孔尺寸： 12X60 mm6. 处理量: 250 t/h III、毕 业设计(论文)工作内容及完成时间：1. 查阅相关资料，外文资料翻译（6000字符以上），撰写开题报告。 第1周第2周2运动及动力参数计算 第3周第4周3总装图设计 第5周第8周 4. 主要零、部件强度及选用计算 第9周第11周5绘制零、部件图 第12周第16周6. 整理毕业论文及答辩准备 第17周 、主 要参考资料：【1】孙桓等主编.机械原理. 北京：高等教育出版社，2001【2】濮良贵等主编.机械设计. 北京：高等教育出版社，2001【3】孙时元. 中国选矿设备手册（上册）. 北京：科学出版社，2006【4】:严峰主编. 筛分机械. 北京: 中国铁道出版社，2001【5】任德树主编. 粉碎筛分原理与设备.北京：北京科技出版社，1988 【6】徐灏主编.机械设计手册（第四版）.北京：机械工业出版社.1991【7】Shigley J E,Uicher J J.Theory of machines and mechanisms.New York:McGraw-Hill Book Company,1980 南昌航空大学科技学院 机械设计制造及其自动化 专业 0781052 班彭明明学生（签名）： 日期： 自 2011 年 2 月 23 日至 2011 年 月 日指导教师（签名）： 助理指导教师(并指出所负责的部分)：机械设计 系（室）主任（签名）： 贺红林南昌航空大学科技学院学士论文YAH2460型圆振动筛设计班级：0781052班 姓名：彭明明 指导老师：封立耀摘要目前我国各种选煤厂使用的设备中,振动筛（筛分机）是问题较多、维修量较大的设备之一。这些问题突出表现在筛箱断梁、裂帮、稀油润滑的箱式振动器漏油、齿轮打齿、轴承温升过高、噪声过大等问题,同时伴有传动带跳带、断带等故障。这类问题直接影响了振动筛（筛分机）的使用寿命,严重影响了生产。YAH2460型圆振动筛可以很好的解决此类问题，因此本次设计的振动筛为YAH2460型圆振动筛，该系列振动筛主要用于煤炭行业中物料分级、脱水、脱泥、脱介等作业。其工作可靠，筛分效率高，但设备自身较重。设计分析论述了设计方案，包括振动筛的分类与特点和设计方案的确定；对物料的运动分析；对振动筛的动力学分析及动力学参数的计算；合理设计振动筛的结构尺寸；进行了激振器的偏心块等设计与计算，包括原始的设计参数，电动机的设计与校核；进行了主要零部件的设计与计算，皮带的设计计算与校核，弹簧的设计计算，轴的强度计算，轴承的选择与计算，然后进行了设备维修、安装、润滑及密封的设计，最后进行了振动筛的环保以及经济分析。关键词：振动筛；激振器；圆振动筛YAH-2460 type of round shaker DesignClass：0781052 Student name：pengmingmingSupervisor：fengliyaoAbstractAt present, Chinas coal preparation plant all the equipment used in the shaker is more problems, maintenance of one of the larger equipment. These issues in sieve outstanding performance me off beam, crack help, lubrication oil dilute the box-type vibrator oil spills, fighting tooth gear, bearing temperature rise too high, major issues such as noise, accompanied by dancing with broken belts, such as fault zone. Such issues directly affecting the life of the shaker, which has seriously affected the production. YAH2460round good shaker can solve such problems, so this shaker designed for roundYAH2460shaker, the series of major shaker in the materials used in the coal industry classification, dehydration, desliming, such as referrals from Operations. Its reliable, efficient screening, but their heavy equipment. Design analysis on the design options, including the classification and shaker features and design programmes to be confirmed; materials on the movement of the shaker and the dynamics of the parameters, to design the structure of vibrating screen size; conduct The eccentric block of the exciter, such as design and calculation, including the original design parameters, motor design and verification; were the main components of the design and calculation, belts and check the design and calculation, the design of spring, the axis of Strength, the choice of bearings and calculation and then proceed to the maintenance of equipment, installation, lubrication and seal the design, a shaker final environmental and economic analysis. Key words: shaker; Vibrator; round shakerA A A A PracticalPracticalPracticalPractical ApproachApproachApproachApproach totototo VibrationVibrationVibrationVibration DetectionDetectionDetectionDetection andandandand MeasurementMeasurementMeasurementMeasurementPhysicalPhysicalPhysicalPhysical PrinciplesPrinciplesPrinciplesPrinciples andandandandDetectionDetectionDetectionDetection TechniquesTechniquesTechniquesTechniquesBy: John Wilson, the Dynamic Consultant, LLCThis tutorial addresses the physics ofvibration; dynamics of a spring masssystem; damping; displacement, velocity,and acceleration; and the operatingprinciples of the sensors that detect andmeasure these properties.Vibration is oscillatory motion resultingfrom the application of oscillatory orvarying forces to a structure. Oscillatorymotion reverses direction. As we shall see,the oscillation may be continuous duringsome time period of interest or it may beintermittent. It may be periodic ornonperiodic, i.e., it may or may not exhibita regular period of repetition. The nature ofthe oscillation depends on the nature of theforce driving it and on the structure beingdriven.Motion is a vector quantity, exhibitinga direction as well as a magnitude. Thedirection of vibration is usually describedin terms of some arbitrary coordinatesystem (typically Cartesian or orthogonal)whose directions are called axes. Theorigin for the orthogonal coordinate systemof axes is arbitrarily defined at someconvenient location.Most vibratory responses of structurescan be modeled assingle-degree-of-freedom spring masssystems, and many vibration sensors use aspring mass system as the mechanical partof their transduction mechanism. Inaddition to physical dimensions, a springmass system can be characterized by thestiffness of the spring, K, and the mass, M,or weight, W, of the mass. Thesecharacteristics determine not only the staticbehavior (static deflection, d) of thestructure, but also its dynamiccharacteristics. If g is the acceleration ofgravity:F = MAW = MgK = F/d = W/dd = F/K = W/K = Mg/KDynamicsDynamicsDynamicsDynamics ofofofof a a a a SpringSpringSpringSpring MassMassMassMass SystemSystemSystemSystemThe dynamics of a spring mass system canbe expressed by the systems behavior infree vibration and/or in forced vibration.FreeFreeFreeFree VibrationVibrationVibrationVibration. Free vibration is the casewhere the spring is deflected and thenreleased and allowed to vibrate freely.Examples include a diving board, a bungeejumper, and a pendulum or swing deflectedand left to freely oscillate.Two characteristic behaviors shouldbe noted. First, damping in the systemcauses the amplitude of the oscillations todecrease over time. The greater thedamping, the faster the amplitudedecreases. Second, the frequency or periodof the oscillation is independent of themagnitude of the original deflection (aslong as elastic limits are not exceeded).The naturally occurring frequency of thefree oscillations is called the naturalfrequency, fn:ForcedForcedForcedForced VibrationVibrationVibrationVibration. Forced vibration isthe case when energy is continuouslyadded to the spring mass system byapplying oscillatory force at some forcingfrequency, ff. Two examples arecontinuously pushing a child on a swingand an unbalanced rotating machineelement. If enough energy to overcome thedamping is applid, the motion willcontinue as long as the excitation continues.Forced vibration may take the form ofself-excited or externally excited vibration.Self-excited vibration occurs when theexcitation force is generated in or on thesuspended mass; externally excitedvibration occurs when the excitation forceis applied to the spring. This is the case, forexample, when the foundation to which thespring is attached is moving.TransmissibilityTransmissibilityTransmissibilityTransmissibility. When the foundationis oscillating, and force is transmittedthrough the spring to the suspended mass,the motion of the mass will be differentfrom the motion of the foundation. We willcall the motion of the foundation the input,I, and the motion of the mass the response,R. The ratio R/I is defined as thetransmissibility, Tr:Tr = R/IResonanceResonanceResonanceResonance. At forcing frequencieswell below the systems natural frequency,R I, and Tr 1. As the forcing frequencyapproaches the natural frequency,transmissibility increases due to resonance.Resonance is the storage of energy in themechanical system. At forcing frequenciesnear the natural frequency, energy is storedand builds up, resulting in increasingresponse amplitude. Damping alsoincreases with increasing responseamplitude, however, and eventually theenergy absorbed by damping, per cycle,equals the energy added by the excitingforce, and equilibrium is reached. We findthe peak transmissibility occurring whenfffn. This condition is called resonance.IsolationIsolationIsolationIsolation. If the forcing frequency isincreased above fn, R decreases. Whenff=1.414 fn, R = I and Tr = 1; at higherfrequencies R I and Tr 1. At frequencieswhen R 0.1 in., to make them practical.The change in intensity or angle of alight beam directed onto a reflectivesurface can be used as an indication of itsdistance from the source. If the detectionapparatus is fast enough, changes ofdistance can be detected as well.The most sensitive, accurate, andprecise optical device for measuringdistance or displacement is the laserinterferometer. With this apparatus, areflected laser beam is mixed with theoriginal incident beam. The interferencepatterns formed by the phase differencescan measure displacement down to 1 MHz insome PR shock accelerometers.Most contemporary PR sensors aremanufactured from a single piece of silicon.In general, the advantages of sculpting thewhole sensor from one homogeneous blockof material are better stability, less thermalmismatch between parts, and higherreliability. Underdamped PRaccelerometers tend to be less rugged thanPE devices. Single-crystal silicon can haveextraordinary yield strength, particularlywith high strain rates, but it is a brittlematerial nonetheless. Internal friction insilicon is very low, so resonanceamplification can be higher than for PEtransducers. Both these features contributeto its comparative fragility, although ifproperly designed and installed they areused with regularity to measure shockswell above 100,000 g. They generally havewider bandwidths than PE transducers(comparing models of similar full-scalerange), as well as smaller nonlinearities,zero shifting, and hysteresis characteristics.Because they have DC response, they areused when long-duration measurements areto be made.In a typical monolithic silicon sensingelement of a PR accelerometer, the 1 mmsquare silicon chip incorporates the entirespring, mass, and four-arm PR strain gaugebridge assembly. The sensor is made froma single-crystal silicon by means ofanisotropic etching and micromachiningtechniques. Strain gauges are formed by apattern of dopant in the originally flatsilicon. Subsequent etching of channelsfrees the gauges and simultaneouslydefines the masses as simply regions ofsilicon of original thickness.The bridge circuit can be balanced byplacing compensation resistor(s) in parallelor series with any of the legs, correctingfor the matching of either the resistancevalues and/or the change of the values withtemperature. Compensation is an art;because the PR transducer can havenonlinear characteristics, it is inadvisableto operate it with excitation different fromthe conditions under which it wasmanufactured or calibrated. For example,PR sensitivity is only approximatelyproportional to excitation, which is usuallya constant voltage or, in some cases,constant current, which has someperformance advantages. Because thermalperformance will in general change withexcitation voltage, there is not a preciseproportionality between sensitivity andexcitation. Another precaution in dealingwith voltage-driven bridges, particularlythose with low resistance, is to verify thatthe bridge gets the proper excitation. Theseries resistance of the input lead wiresacts as a voltage divider. Take care that theinput lead wires have low resistance, orthat a six-wire measurement be made (withsense lines at the bridge to allow theexcitation to be adjusted) so the bridge getsthe proper excitation.Constant current excitation does nothave this problem with series resistance.However, PR transducers are generallycompensated assuming constant voltageexcitation and might not give the desiredperformance with constant current. Thebalance of the PR bridge is its mostsensitive measure of health, and is usuallythe dominant feature in the totaluncertainty of the transducer. The balance,sometimes called bias, zero offset, or ZMO(zero measurand output, the output with 0g), can be changed by several effects thatare usually thermal characteristics orinternally or externally induced shifts instrains in the sensors. Transducer casedesigns attempt to isolate the sensors fromexternal strains such as thermal transients,base strain, or mounting torque. Internalstrain changes, e.g., epoxy creep, tend tocontribute to long-term instabilities. Allthese generally low-frequency effects aremore important for DC transducers thanfor AC-coupled devices because they occurmore often in the wider frequency band ofthe DC-coupled transducer.Some PR designs, particularlyhigh-sensitivity transducers, are designedwith damping to extend frequency rangeand overrange capability. Dampingcoefficients of 0.7 are considered ideal.Such designs often use oil or some otherviscous fluid. Two characteristics dictatethat the technique is useful only atrelatively low frequencies: damping forcesare proportional to flow velocity, andadequate flow velocity is attained bypumping the fluid with large displacements.This is a happy coincidence for sensitivetransducers in that they operate at the lowacceleration frequencies wheredisplacements are adequately large.Viscous damping can effectively eliminateresonance amplification, extend theoverrange capability, and more than doublethe useful bandwidth. However, becausethe viscosity of the damping fluid is astrong function of temperature, the usefultemperature range of the transducer issubstantially limited.VariableVariableVariableVariable CapacitanceCapacitanceCapacitanceCapacitance. VCtransducers are usually designed asparallel-plate air gap capacitors in whichmotion is perpendicular to the plates. Insome designs the plate is cantilevered fromone edge, so motion is actually rotation;other plates are supported around theperiphery, as in a trampoline. Changes incapacitance of the VC elements due toacceleration are sensed by a pair of currentdetectors that convert the changes intovoltage output. Many VC sensors aremicromachined as a sandwich ofanisotropically etched silicon wafers with agap only a few microns thick to allow airdamping. The fact that air viscositychanges by just a few percent over a wideoperating temperature range provides afrequency response more stable than isachievable with oil-damped PR designs.In a VC accelerometer, ahigh-frequency oscillator provides thenecessary excitation for the VC elements.Changes in capacitance are sensed by thecurrent detector. Output voltage isproportional to capacitance changes, and,therefore, to acceleration. Theincorporation of overtravel stops in the gapcan enhance ruggedness in the sensitivedirection, although resistance to overrangein transverse directions must rely solely onthe strength of the suspension, as is true ofall other transducer designs withoutovertravel stops. Some designs can surviveextremely high acceleration overrangeconditions-as much as 1000 full-scalerange .The sensor of a typicalmicromachined VC accelerometer isconstructed of three silicon elementsbonded together to form a hermeticallysealed assembly. Two of the elements arethe electrodes of an air dielectric,parallel-plate capacitor. The middleelement is chemically etched to form arigid central mass suspended by thin,flexible fingers. Damping characteristicsare controlled by gas flow in the orificeslocated on the mass.VC sensors can provide many of thebest features of the transducer typesdiscussed earlier: large overrange, DCresponse, low-impedance output, andsimple external signal conditioning.Disadvantages are the cost and sizeassociated with the increased complexityof the onboard conditioning. Also,high-frequency capacitance detectioncircuits are used, and some of thehigh-frequency carrier usually appears onthe output signal. It is generally not evennoticed, being up to three orders ofmagnitude (i.e., 1000 ) higher infrequency than the output signals.ServoServoServoServo (Force(Force(Force(Force Balance)Balance)Balance)Balance). Althoughservo accelerometers are usedpredominantly in inertial guidance systems,some of their performance characteristicsmake them desirable in certain vibrationapplications. All the accelerometer typesdescribed previously are open-loop devicesin which the output due to deflection of thesensing element is read directly. Inservo-controlled, or closed-loop,accelerometers, the deflection signal isused as feedback in a circuit that physicallydrives or rebalances the mass back to theequilibrium position. Servo accelerometermanufacturers suggest that open-loopinstruments that rely on displacement (i.e.,straining of crystals and piezoresistiveelements) to produce an output signal oftencause nonlinearity errors. In closed-loopdesigns, internal displacements are keptextremely small by electrical rebalancingof the proof mass, minimizing nonlinearity.In addition, closed-loop designs are said tohave higher accuracy than open-loop types.However, definition of the termaccuracyvaries. Check with the sensormanufacturer.Servo accelerometers can take eitherof two basic geometries: linear (e.g.,loudspeaker) and pendulous (metermovement).Pendulous geometry is most widelyused in commercial designs. Until recently,the servo mechanism was primarily basedon electromagnetic principles. Force isusually provided by driving currentthrough coils on the mass in the presenceof a magnetic field. In the pendulous servoaccelerometer with an electromagneticrebalancing mechanism, the pendulousmass develops a torque proportional to theproduct of the proof mass and the appliedacceleration. Motion of the mass isdetected by the position sensors (typicallycapacitive sensors), which send an errorsignal to the servo system. The error signaltriggers the servo amplifier to output afeedback current to the torque motor,which develops an opposing torque equalin magnitude to the acceleration-generatedtorque from the pendulous mass. Output isthe applied drive current itself (or across anoutput resistor), which, analogous to thedeflection in the open-loop transducers, isproportional to the applied force andtherefore to the acceleration.In contrast to the rugged springelements of the open-l