Study On Vibration Characteristics Of Scroll Compressor Based On Analytic Hierarchy Process

With the popularization of scroll compressor,it becomes more and more important.The stability of scroll compressor is directly related to its performance,and the vibration signal is the language of its working performance.In order to obtain the target parameters,it is necessary to use the corresponding method to analyze the vibration signal of scroll compressor.Due to the unique structure of scroll compressor,the vibration of the shell is complex.However,in the literature about the vibration signal of scroll compressor,it is lack of a systematic study of the particularity of the vibration on the shell surface.In addition,due to the short research time and the lack of real-time monitoring method,the performance of scroll compressor can not be judged.Based on the special structure of scroll compressor,this paper puts forward four special position of vibration as the research object.That is,the wall of the exhaust port,the moving scroll plate and the cross slip ring,the main bearing and the supplementary bearing of the crankshaft are corresponding to the shell.The forces and moments of these position are analyzed,and the causes of vibration in different positions are obtained.The vibration test system of scroll compressor is established,and the vibration signal of the special position is obtained,and carry on median filtering,so as to eliminate the interference and interference of the signal to the utmost.Using the root mean square value and variance in the time domain,the vibration is analyzed and the vibration fluctuation is obtained.It is research that the position of the shell corresponding to the orbiting scroll and cross slip ring produces the greatest degree of vibration,and fluctuates most violently.Subsequently,this paper puts forward the concept of the contribution value of vibration for the first time.This value is obtained by using analytic hierarchy process.In the use of analytic hierarchy process,this essay puts forward a new judgment matrix in order to reduce the calculation error of scroll compressor,namely integrated signal power spectrum and deflection function of both established.Finally,the contribution ratio of special position for the whole vibration of scroll compressor is obtained.The results show that the contribution ratio of the vibration at the exhaust nozzle wall is the largest,and the position is the greatest impact on the overall vibration of the scroll compressor.This phenomenon shows that the axial vibration of scroll compressor can not be neglected in the study of vibration reduction.According to the contribution ratio,the scroll compressor running condition can be monitored in real time.When the ratio of contributions appear large fluctuations,it can reflect the corresponding position of failure may occur.According to the analysis of the special position force and moment,we can judge the most possibility of the fault.The method can be used as a theoretical basis for the fault diagnosis of scroll compressor.Based on the calculation theory,this paper makes use of MATLAB software to edit the program,and the program is used in the experimental system.During the experiment,the program can directly display the vibration signal in time domain and the change of the characteristic value,and the power spectrum,coherence function and partial coherence function between the different positions.The most important function is that it can directly show the contribution ratio of different positions for the scroll compressor vibration,and achieve the purpose of real-time monitoring of scroll compressor operation.