Research On Vertical Water Pump Vibration Isolation Based On Positive And Negative Stiffness Springs Parallel

The use of pump which is the equipment to enhance the water pressure become more andmore widely. The vibration and noise caused by the work of pump can not be ignored becausethe noise would influence people’s living environment. In order to improve the livingenvironment of the high-rise buildings, a vibration isolator which has low natural frequency isdesigned, it can effectively reduce the vibration that is passed by pump to the base, reduce thevibration that are transmitted between floors.The paper analyzes the basic principle of negative stiffness isolator; and a negativestiffness institutional model through the study of the negative stiffness of vibration isolationconcept is designed. The mechanical characteristics of negative stiffness model are obtained.Then the positive stiffness of the support component is added to the model. Through theresearch of the system’s mechanical properties in vertical and horizontal directions, effects ofvarious parameters of the system are obtained.The combined positive and negative stiffness isolator’s mathematical model isestablished. Through the harmonic balance method and linear analysis method, the dynamiccharacteristics of the system by the harmonic excitation is analyzed, and the amplitude of thepump after the vibration isolation system in horizontally and vertically direction is obtained.Amplitude’s calculation formula of the isolated pump in horizontal and vertical direction isobtained. Comparing the accuracy of the two methods, the linear analysis method can meetthe accuracy requirements in the analysis of small displacement. Through analyzing theinfluence on the force transfer rate by the system structure parameters, the optimizedparameters are obtained in theory, in order to achieve the best vibration isolation.Experiments are finished to measure the acceleration signal of the pump under normaloperating conditions, the pump force’s spectrogram is obtained by fast Fourier transform,selected spectrogram force energy input model, obtained the amplitude and transmitted to the amplitude of the force on the docking station after vibration isolation. Isolation effect ofthe positive and negative stiffness parallel system is gained. The size of each spare parts theisolator is designed and its reliability is analyzed. Through the ADAMS the designedvibration is simulated, the theoretical result is verified and the system can effectively isolatethe pump’s vibration, so as to achieve the purpose of vibration and noise reduction.