Study On Field Balancing Technology For Rotors Of Paper Machinery

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.