Research On Maintenance Technique Oriented To The Vibtation Performance Of A Centrifugal Pump Based On Force Source Recognition Theory

Research on the control of vibration and sound from mechanical equipment arouse widely discussions since vibration is seen as an important factorto evaluate the performance of mechanical equipment. Nowadays, most researches considering the vibration control at the stage of the design of mechanical equipment. However, maintenance, as a significant loop to keep equipment operating in good condition, has not been focused. Furthermore, the lack of vibration standards in maintenance specifications also motivates research towards low vibration maintenance technology. This paper take a 30kW centrifugal pump as an object and research on vibration control technology at equipment maintenance stage has be carried on.Firstly,vibration responses and structural vibration modes of centrifugal pump were tested. Measured data show that the acceleration amplitude of mountsexceed technical permitted valueabout 7dB. Moreover, resonance behaviors could be ruled out through modal test.Then, based on the measured data combined with finite element modeling, the force loads on the pump group are identified.Accordingly,the causes of over standard on vibration are figured out through analysis of power source characteristics. After that, suggestions on pump maintenance oriented to vibration control were proposed. Integrated with some practical engineering conditions, the accuracy of rotor balancing, centering of coupling alignment,grinding of shaft, and aging of isolators etc. are selectedfor repair or replacement. Vibration response tests show that after maintenance the response of the vibration amplitude was greatly attenuated anda reduction up to 12dB was obtained.There is still severe vibration for specific characteristic frequencies of the pump after maintenance. Passive isolators were chose to fix that problem owing to its condensed structure, low cost, good performance on vibration absorber, and convenience for repair. An adjustable absorber was designed and verified through dynamic analysis and the installation condition was also taken into account.After the installation of vibration absorber,a further vibration reduction up to 12dB of considered line spectrum was obtained.