【作者】 张飞超；

【导师】 张辉；

【作者基本信息】 南京林业大学 ， 制浆造纸工程， 2007， 硕士

【摘要】 近年来造纸机车速不断提高,幅宽不断增加,中高速纸机国产化关键技术研究已经进入我国“863”计划。对于中高速纸机,在生产过程中旋转件不平衡问题变得更加突出,已成为必须关注的重要问题。而采用现场动平衡技术能够改善纸机旋转件的工作性能,并带来显著的经济效益。本文对造纸机械旋转件现场动平衡技术做了系统的研究,必将推进这项技术在我国造纸行业的发展和应用。本文从理论上有针对性地分析了造纸机械旋转件不平衡的类型、振动机理,以及相应平衡理论方法;探讨了造纸机械旋转件及其支承系统的典型故障的机理、构件系统在诊断不平衡等过程中可能存在的影响;通过转子实验台模拟分析了造纸机旋转件的典型故障和现场动平衡过程;建立了造纸机械现场动平衡分析系统,探讨了动平衡分析系统的现场安装过程;最后,通过复卷机进行了现场动平衡实践。本文研究结果如下:(1)在现场动平衡研究中,可将造纸机械旋转件—支承系统看作单自由度振动系统处理。确定了辊体的平衡品质以及允许不平衡量在校正面上的分配。由于造纸机旋转件表面属于工作区,一般不宜作为校正面。因此,校正面位置仅限于两端,对大直径辊体可在端面附加片状质量块进行校正,对小直径辊体可在辊壳内表面附加棒状平衡重进行校正。(2)造纸机械转子系统中,各零部件故障相互影响,可能有两个或两个以上故障的耦合出现,导致振动信号特征相互叠加,增加了诊断的难度。对此,可先通过转子实验台对现场可能存在的故障进行模拟分析确定。(3)现场动平衡模拟实验结果表明,采用影响系数法可以快速有效地实现刚性转子平衡校正,更适于造纸机旋转件的现场动平衡。另外,平衡过程中发现校正面位置的选择会对平衡质量产生明显的影响。而采用振型平衡法可很好的实现转子过1阶临界转速的平衡,但此方法起停车次数多,计算较为复杂。(4)采用非接触电涡流传感器测轴振,减少了轴承缺陷故障振动的干扰,快速、准确实现了对不平衡故障的诊断。考虑到某些转子组成部分涡流传感器安装不便,制定了以加速度传感器代替涡流传感器进行信号采集的备用方案。动平衡分析系统设计为三个模块,即故障监测诊断模块,数据管理模块和动平衡计算分析模块。便于实现对转子系统故障监测诊断,提高诊断效率,同时也提高了现场动平衡的效率。(5)确定了校正配重计算方法,并设计了标准配重质量块尺寸和安装方式。(6)通过对复卷机底辊的现场测试与动平衡实践,成功地将辊体的不平衡量控制在允许范围内,说明应用本文成果于造纸机械实际是可靠可行的。更多还原

【Abstract】 In recent years, operating speed of paper machine continuously going up, the width increased, domestic research of key technologies on high-speed Machine have been listed into China’s "863" programs. For high-speed machine, in the production process rotating parts unbalance becomes more prominent, and has become an important problem which must be concerned. Application of field balancing technique can improve performance of the rotating parts of paper machine and take significant economic benefits. In this paper, the systemic study of field balancing was done, for rotors of paper machinery, and this would promote this technology’s development and application in China’s paper industry.Theoretically, the types of unbalance and vibration mechanism of rotating parts of paper machinery, and the corresponding balancing theory were analyzed; The typical fault mechanism of rotating parts and support systems of paper machinery was discussed, and the effect of component systems in the diagnosis of unbalance which might exist was analyzed; Through rotor test-bed, simulation analysis on typical faults in place and field balancing of rotors of paper machinery was done; Develop the field balancing analysis system of paper machinery, and explore on-site installation process for the balancing analysis; Finally, the winder was balanced in place.The results were as follows:(1) In field balancing research, rotor-support system of paper machinery can be a single-freedom vibration system. The balance quality of roller and distribution of permissible unbalance on the end surface were determined. As the surface of rotating parts of paper machine was the working area, generally not suitable to be correction plane. Therefore, the position of correction plane was limited to two ends. For large-diameter rollers flake correction mass was added to the end surface, and for small-diameter rollers the rod of correction weight was added to inner surface of the roller crust.(2) For paper machine rotor systems, faults of the components affect each other, may have two or more coupling fault-exist, and Superposition of characteristics of the vibration signal make the diagnosis more difficult. In this regard, we may do fault simulation analysis on possible faults in place through rotor test-bed.(3) Simulation results of field balancing indicates that using the influence coefficient method can quickly and efficiently achieve rigid rotor’s dynamic balance, more suitable for rotors of paper machinery. In addition, the choice of correction plane is found to have a clear impact on quality of balance. And modal balancing method can be used to balance a rotor over 1st critical speed, but this method demands many times startup and stop of machine, and its calculation is more complex.(4) Non-contact eddy current sensors were used to measure shaft vibration, to reduce vibration disturbances of the bearing defect, and rapidly, accurately realize diagnosis of unbalance fault. Taking into account the installation of eddy current sensors for some rotor components inconvenient, the spare plan of low frequency accelerometers was developed to replace eddy current sensors for signal acquisition. Balancing analysis system was designed for the three modules, namely, fault monitoring and diagnosis module, Data Management module and balance calculation and analysis module. Facilitated the achievement of monitoring and fault diagnosis for rotor system, and improved the diagnostic efficiency and the efficiency of field balancing.(5) Determine the calculating method of counterweight, and design a standard size counterweight block and the installation method of counterweight.(6) By field testing and balancing practice for the bottom roller of winder, roller unbalance was controlled within the permissible range. It shows that the result of this paper used to paper machinery is reliable and feasible.更多还原