Research On Dynamics Of Variable Mechanism Of Floating Cup Pump And Pump Output Characteristics

As one of the most widely used power components in modern hydraulic transmission,the plunger pump has the characteristics of high efficiency,long service life,light weight per unit power and high adjustable parameters,and the floating cup type with comparative advantages in structure and performance The axial piston pump(hereinafter referred to as the floating cup pump)has attracted attention in the hydraulic industry in recent years.For quantitative floating cup pumps,the main advantages are high efficiency,low output flow and pressure pulsation,high power density,etc.However,there are few researches on variable floating cup pumps,and the traditional valve-controlled variable structure is applied to floating cup pumps.The cup pump has certain shortcomings and defects.For this reason,this research topic designed a new type of floating cup pump variable mechanism by combining theoretical analysis,design modeling and simulation,and analyzed the advantages of this mechanism compared to the traditional variable mechanism and the output characteristics of the pump.,Provide a certain theoretical basis for the design of variable floating cup pump.First of all,the core part of the floating cup pump is its internal mirror-symmetrically distributed rotating body structure.Therefore,using this structure as the main line,the working principle,structure and performance characteristics of the quantitative floating cup pump are introduced,and the size parameters of its main components are deduced.The influence on the pump power density,and the theoretical flow and pulsation of the pump are analyzed,and the quantitative floating cup pump is introduced in more detail.When the traditional valvecontrolled variable mechanism is applied to the floating cup pump,there are disadvantages that it is difficult to achieve synchronous control on both sides of the swash plate,the servo valve is easily contaminated by oil,and the compressibility of the hydraulic oil itself is difficult to achieve precise control.Therefore,a design is designed.The main structure of the variable floating cup pump is based on the servo motor,ball screw,swash plate push rod and the rotating body structure of the pump.Secondly,the maximum load torque that the motor shaft can bear and the driving torque required for the ball screw pair to convert from rotary motion to linear motion are calculated to facilitate the comparison and verification of simulation results and theoretical analysis.And through analysis and simulation,the motion constraint relationship between the components is determined,driving and setting simulation parameters are applied to it,and the dynamic simulation model of the overall structure is established.Then,through the dynamic simulation analysis of the overall mechanism,it is shown that under the action of the variable mechanism,the response time of the swash plate inclination angle from 0° to 8° is about 0.088 s,which is compared with the traditional valve-controlled variable mechanism The response time of 0.1 s has a certain improvement.The rationality of the selection and design of the return spring is verified by calculation,and the movement speed and acceleration change law of the center of mass of the floating cup in the variable process are analyzed.The simulation result is basically consistent with the theoretical calculation result,which further illustrates that the variable structure is better than the valve.The controlled variable structure is more advantageous.Finally,in order to analyze the output characteristics of the variable floating cup pump,the servo motor model was established using Matlab/Simulink software,and the overall hydraulic model of the pump was built using AMEsim software.The output characteristics of the variable floating cup pump were obtained through co-simulation.Comparing it with theoretical analysis,the results show that: the output flow and pressure of the pump fluctuate periodically;under certain conditions of speed and load pressure,the theoretical flow pulsation of the pump is basically the same as the simulated flow pulsation,and is relatively oblique to the general slope.From the perspective of disc axial piston pump,its flow pulsation performance is much better;under the conditions of fixed speed and swash plate inclination angle,the flow pulsation coefficient of the pump outlet increases with the increase of load pressure,compared with the general The swash plate type axial piston pump,its flow pulsation performance under different load pressure changes lower and more stable.