Research On The Vibration Characteristics Of Seawater Piston Pump Used In The Naval Ship

Drainage system is one of the important systems to ensure the safety and vitality of naval ship,and seawater piston pump is usually used as the power source of drainage system.However,strong vibration and noise will be produced in the working process of seawater piston pump,which will seriously affect the concealment and safety of naval ship.Therefore,it is of great significance to analyze the vibration mechanism of drainage pump and adopt corresponding vibration reduction measures to enhance the combat effectiveness of naval ship.Modal analysis has become one of the key technologies of piston pump structural dynamic analysis.Based on the analysis of vibration mechanism of seawater piston pump,a new operational modal analysis method of piston pump which based transsissbility was proposed in this paper.The proposed method was used to identify the natural frequency and vibration peak of seawater piston pump,the resonance frequency can be avoided by adjusting the support stiffness of seawater piston pump,and the vibration peak of seawater piston pump can be reduced by reducing pressure pulsation,so as to reduce the vibration of seawater piston pump.The research contents of this paper are as follows:1)According to the structure and working principle of seawater piston pump,the multibody dynamic model of the moving parts of the seawater piston pump was constructed.Then the vibration source and frequency of seawater piston pump were simulated and analyzed,and the vibration mechanism of seawater piston pump was obtained.2)Based on the theory of modal analysis and working principle of piston pump,in this paper,a transsissbility based operational modal analysis method of piston pump under pressure excitation was proposed,and the modal parameters of seawater piston pump were identified by the proposed method.The relationship among the vibration frequency,natural frequency and vibration peak of seawater piston pump was compared and analyzed,and conclusion can be obtained that the resonance of seawater piston pump would occur at its natural frequency.It was pointed out that the vibration of seawater piston pump can be reduced by changing the natural frequency of seawater piston pump and reducing pressure pulsation.3)To avoid resonance of seawater piston pump,the natural frequency of seawater piston pump was modified by adjusting its support stiffness.The dynamic model of the rubber isolator with seawater piston pump was constructed.The influence of the dynamic stiffness of the rubber isolator on the dynamics of seawater piston pump was analyzed theoretically.The relationship between the rubber isolator's dynamic stiffness and the natural frequency of seawater piston pump was obtained through experimental modal analysis.The relationship between the dynamic stiffness of rubber isolator,the pressure condition and the vibration of seawater piston pump was studied experimentally,and the influence of the dynamic stiffness of rubber isolator on the vibration of seawater piston pump was revealed.4)The mechanism of restraining pressure pulsation were studied,and a structure of seawater piston pump with integrated accumulator group was proposed,so as to reduce the pressure pulsation and vibration of seawater piston pump.The relationship between the key parameters of accumulator group,such as volume and pressure,and the pressure pulsation and vibration characteristics of seawater piston pump was analyzed theoretically and experimentally.5)Based on the above research,under the condition that the pressure pulsation of seawater piston pump was small under multi-pressure conditions,the influence of different rubber isolators'dynamic stiffness on the vibration of seawater piston pump was experimentally analyzed.The dynamic stiffness of rubber isolator under the minimum vibration of seawater plunger pump can be obtained,and the corresponding vibration of seawater plunger pump was reduced by 4.7dB/(1.0?m/s~2).In this paper,modal analysis of seawater piston pump was conducted,and the influence of rubber isolator's dynamic stiffness and pressure pulsation on the vibration of seawater piston pump was studied.The results showed that choosing appropriate rubber isolator's dynamic stiffness and accumulator's inflation parameters can effectively reduce the vibration of seawater piston pump under multi-pressure conditions.The research methods and achievements in this paper can open up new ideas for vibration and noise reduction of piston pump,and have practical research significance and application value.