| Non-circular gear pump is a new type of positive displacement pump,both of cam pump and gear pump advantages,with large displacement,high volumetric efficiency.However,in the process of fluid transportation,it is easy to produce intense instantaneous flow pulsation,which causes vibration and noise of pump body and pipeline,which seriously limits the application of non-circular gear pump in engineering.It is of great significance to study the dynamic characteristics of non-circular gear pump and put forward the flow pulsation calming method to improve the performance of non-circular gear pump.In this paper,by researching the kinematic characteristics of the transmission system of non-circular gear pump and the flow characteristics,a method combining ADAMS-Simulink co-simulation and computational fluid dynamics(CFD)numerical simulation is proposed to use PID technology to real-time control the speed of the drive motor flow pulsation calming scheme.To achieve non-circular gear pump cushioning vibration and instantaneous flow pulsation.Firstly,the equation for the pitch curve and the calculation formula for the primary design parameters of the non-circular gear were deduced,and a 3D solid model of the non-circular gear was created.Check the sealing,pressure Angle and root cutting condition of the joint curve.The tooth profile curve of non-circular gear was obtained by MATLAB virtual machining software,and the three-dimensional solid model of non-circular gear was established by Solid Works software.Secondly,The dynamic properties of the non-circular gear pump have been analyzed,encompassing the transmission system’s kinematic characteristics and the fluid flow properties of the pump.This study has been conducted using MATLAB and ADAMAS.The effects of rotor order and eccentricity on transmission ratio,angular velocity and angular acceleration of driven wheel were analyzed.This paper expounds the working principle of non-circular gear pump,deduces the calculation formula of displacement and instantaneous flow of non-circular gear pump,and draws the conclusion that dynamic characteristics of non-circular gear pump are closely related to instantaneous flow pulsation.Then,the flow pulsation stabilization method based on parallel oval-shaped gear pump is studied.The internal flow field of oval gear pump was simulated by CFD based on Fluent to analyze the internal flow rate and pressure.The flow field model of parallel oval-shaped gear pump is established and three-dimensional flow field simulation is implemented.The results show that the flow pulsation rate decreases by 25.66%,but there are many defects in this method.Finally,using ADAMS-Simulink co-simulation and CFD numerical simulation method,based on PID control technology to develop mechatronic flow pulsation suppression scheme,reduce the vibration and impact of the transmission system,greatly reduce the flow pulsation rate.Through ADAMS and Simulink co-simulation,the PID control technology is used to control the speed of the motor in real time,so as to control the angular velocity motion law of the gear pump rotor,and realize the shock buffering.Combined with the numerical model of the internal flow field of the oval gear pump,the data interaction between Fluent UDF and Simulink was realized by using the Visual Studio platform and the program.In the flow field model,the transmission relation of gear pump rotor speed ratio after PID control is precisely simulated,and the flow pulsation of oval gear pump is reduced by 30.72%.Compared with the parallel oval-shaped gear pump,the flow pulsation rate decreased by 5.06%.In this paper,ADAMS-Simulink co-simulation and CFD numerical simulation combined simulation method,proposed a real-time control of the drive motor by PID technology flow pulsation suppression scheme,compared with parallel oval-shaped gear pump,the method can produce better suppression effect without increasing the pump body structure.Moreover,it has the advantages of low cost and high flexibility,which provides theoretical methods and design basis for the research and optimization design of pulsation calming of non-circular gear pump. |
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