Research Of The Whole-machine Balancing Method Based On Amplitude Measurement And Instrument Development

Unbalance vibration is the main factor of disturbing the rotating machinery's normal work,the method of whole-machine dynamic balancing based on amplitude-phase with less start and high precise,in which the rotor's key phase and the vibration signal is test to calculate the magnitude and phase of unbalance,is often used in industry.But the large scale of axial-flow fans as the representative,the structural characteristics of this kind rotating machinery can not be extracted the rotor's key phase information by phase-sensitive sensor,So the whole-machine measurement principle has been deeply studied in this paper,a set of dynamic balance system has been successfully developed,which can be well applied in the field,and the balancing experiment has been done in the 4-72 plastic centrifugal fan and experiment balancing rotor.According the study of this subject,some recent conclusions are achieved as followed:1.An effective identification method of unbalance amplitude has been proposed.Firstly the original vibration signal has been calculated with secondary circle auto-correlation in order to catch the information of the rotor speed,then the sine and cosine signal in working frequency has been constructed to do the cross-correlation with the original vibration and the vibration after test weigh has been put on,according the feature of the Fourier series,the noise and different frequency components has been restrained,and the vibration caused by unbalance has been detected from the complex vibration signals.2.The method of the whole-machine balancing based on amplitude measurement has been studied,Firstly the original imbalance amplitude and three imbalance amplitudes which has been put on the try weight has been effectively identifyied,and the magniture and phase of the unbalance has been calcaulated by three ball method.3.A set of amplitude whole-machine balancing instrument based on STC12C5410AD single-chip has been developed.The design of the vibration signal pre-processing such as low-pass filter,differential amplification,auto-range,signal bias etc,realize of human computer interaction module like keyboard and LCD,and software programming of the amplitude whole-machine balancing method and the function instrument need realize have been mainly discussed in this paper.4.The whole machine balancing experiment has been respectively done in the 4-72 plastic centrifugal fan and laboratory fan,and comparative experiment has been done using CUT-62 vibration measurement instrument and PCDB-1 notebook balancing test systems,the result indicate that developed instrument has a better performance on catching the unbalance than CUT-62 vibration measurement instrument,and reach the function of PCDB-1 notebook test instrument.