| The ball piston pump is a new type of displacement hydraulic pump with a ball piston as the piston,which has received wide attention because of its compact structure and high power density ratio.The output characteristics of the ball piston pump are affected by multiple factors such as working medium,working load and interaction between internal parts simultaneously during operation,and it is difficult to consider multiple factors simultaneously in theoretical analysis.Virtual prototype technology is widely used in the development of hydraulic components with its advantages of high efficiency,low cost,good repeatability and low risk.Therefore,this paper uses AMESim and ADAMS simulation software to establish a virtual prototype simulation model of a single track eccentric radial pump ball piston pump,analyze the working mechanism of the radial ball piston pump,study the effect of different working conditions on the output flow,output pressure and output pulsation rate of the radial ball piston pump,provide a reference for the manufacture of the physical prototype of the radial ball piston pump and reduce the development cycle of the prototype,the main research contents of this paper include:(1)Based on the mathematical model of single track eccentric radial pistons pump,analyze its working principle,study the kinematics and dynamics of the pistons in the rotation process,derive the equations for the output flow characteristics of the radial pistons pump,determine the structural dimensions of the radial pistons pump,and complete the construction of the model of the radial pistons pump by using Solid Works software.(2)Using AMESim software,the hydraulic model of radial piston pump is created,and a single piston super element is built to improve the simulation efficiency.The effects of oil viscosity,oil gas content,piston bore clearance,piston sub-seal length and number of pistons on the pump output characteristics are studied.The results show that when the oil viscosity is low,the sealing effect of the ball piston sub-element is poor and the working efficiency is low;the oil gas content increases,the oil compressibility is enhanced,which will seriously affect the output pulsation rate of the pump outlet;the line seal between the ball piston and the cylinder bore,when the ball piston cylinder bore clearance is0.005 mm and the ball piston sub-seal length is 0.0005 mm,the leakage of the ball piston chamber is small and the output pulsation is smooth;the odd number of ball pistons is obviously The output characteristics of odd number of pistons are obviously better than even number of pistons,and the best number of pistons is obtained.(3)Using ADAMS software,a multi-body dynamics model of the ball piston pump is established,considering the contact constraints between the ball piston subsets,and the displacement curve,velocity curve and rotation curve of the ball piston under different working conditions are analyzed.A rigid-flexible coupling model is established,which shows the stress change of the rotor during the rotation of the ball piston pump,with the maximum stress in the high-pressure area,and analyzes the rotor modal changes,providing a basis for the subsequent structural optimization.(4)Using the Co-simulation port,the hydraulic model and the multi-body dynamics model are jointly simulated to establish a virtual prototype of the radial ball piston pump,and the effects of different rotational speeds and different loads on the output flow and output pressure of the virtual prototype of the radial ball piston pump are studied.The results show that as the output load increases,the pressure fluctuation in the ball piston chamber increases and the output pulsation rate at the pump outlet becomes larger;when the output load is less than 15 MPa,the output characteristics of the pump are smooth;as the input speed increases,the output flow and output pressure of the ball piston pump increase,the output pulsation is smooth and the ball piston pump can operate stably at high speed. |
