| Hydraulic system is widely used in engineering machinery,ship,aerospace and other fields because of its advantages of high power density,high performance and adaptability to complex conditions.With the constant improvement of the stability and high precision of the hydraulic system,the study on the vibration and noise in hydraulic system has become a hot issue.Pressure pulsation is the main noise source of the hydraulic system,and it affects the working reliability and performance stability of the hydraulic system.Therefore,it is of important scientific research value and practical significance to systematically study the mechanism and influence factors of pressure pulsation.Based on the closed type hydraulic system,the mathematical model of pressure pulsation coupling for pump and motor is established.The mechanism of the pressure pulsation of the piston pump / motor is analyzed.And the simulation model of closed hydraulic system is set up by AMEsim simulation software.The influence of the structure parameters,the system working condition and the phase angle on the pressure pulsation of the hydraulic system is also studied.It provides a theoretical basis for the research on the performance optimization of hydraulic system,vibration and noise reduction and so on.The main contents of this work are shown as follows.(1)The mechanism of pressure pulsation in hydraulic system is studied.According to the working principle of the closed system and the mechanism of pressure pulsation in piston pump / motor.A mathematical model of pressure pulsation coupling in a pump controlled motor closed system is established.Then the simplified model of the system is established by using AMEsim simulation software and the simulation analysis is carried out and the accuracy of the model is verified by experiments.The model simulation platform is provided for the study of the structural parameters and the environment conditions on pressure pulsation characteristics in the hydraulic system.(2)The effect mechanism of structure parameters,working condition parameters and phase on pressure pulsation is simulated and analyzed.The AMEsim model of the pump control motor hydraulic system and the AMEsim simulation model of single plunger pump are established respectively.And The influence of different working conditions on pressure pulsation is compared.The results show that the increase of the plunger number will cause the reduction of the pressure pulsation of the system,but the decrease of the single plunger pump is slower.The change of pipe length and inner diameter will reduce the pressure fluctuation of the system and the pressure coupling characteristic of the pump motor.The change of oil characteristics will cause the increase of pressure pulsation of the system,but the relative influence is small.The motor speed will cause the pressure fluctuation of the system to decrease in a certain range.The increase of the system load will lead to the increase of pressure pulsation and the enhancement of the coupling characteristics of the pump motor.The change of phase difference can effectively reduce the pressure pulsation in the system.(3)The influence of speed,load,pipeline and phase on the pressure pulsation characteristics of the system is investigated experimentally.The experimental results show that the amplitude and pulsation rate of the system pressure pulsation will increase first and then decrease with the increase of motor speed.The increase of the load will cause a large increase in the amplitude of the pressure pulsation and a slower reduction in the pressure pulsation rate.Pipeline energy and effective reduction of system pressure pulsation and pump motor pulsating coupling characteristics.The phase difference has the greatest influence on the pressure pulsation,which can cause the fluctuation of the amplitude of the pressure fluctuation to be about 3%.The results verify the validity of the theory and simulation analysis,which provides a theoretical basis for the research of active vibration control and phase active filtering to achieve system vibration and noise reduction.(4)The effect of installation location,inflation pressure,volume,length and inner diameter of accumulator on pressure pulsation is simulated and analyzed.The results show that the accumulator is an effective method to reduce the pressure pulsation in the system,and its installation position,inflatable pressure,volume,length and inner diameter of the pipe have a great influence on its attenuation characteristics.The parameters of accumulator,which best suppress the pulsation in the system,are clarified,which provides a theoretical reference for the optimal design and performance improvement of the system. |
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