Pressure Characteristics In Cavity Of Swash Plate Axial Piston Pump With Conical Cylinder

Hydraulic transmission technology is a kind of industrial control technology which takes liquid as medium and uses liquid pressure to transmit power.Because of its large output force,wide range of adjustment,high power density and many other advantages,it is widely used in construction machinery,aerospace,ship navigation and other fields.Axial piston pump is divided into cylindrical cylinder and conical cylinder.The conical cylinder axial piston pump is mostly used in large piston pump.The main reason is that the conical cylinder structure can effectively reduce the overall size of the plunger pump and is conducive to the oil absorption of the plunger pump.Aiming at the problem that the oil volume in the plunger chamber changed rapidly when the conical cylinder axial piston pump was working,and the pressure pulsation and pressure impact in the chamber caused the vibration and noise of the piston pump,the performance of the piston pump was affected.The purpose of this paper is to discuss and analyze the characteristics of the pressure in the cavity of the axial piston pump with conical cylinder,and to understand the relationship between the pressure in the cavity and its influencing factors.Therefore,it is of great significance to reduce the noise and improve the performance of piston pump.In this paper,the A4 VSO piston pump was taken as the research object.Firstly,the working principle of A4 VSO conical cylinder piston pump was introduced,and the mathematical model of piston movement was deduced and analyzed by mathematical method.Based on the theoretical analysis of the pressure in the piston cavity,the mathematical model of the valve area was established,and the theoretical expression of the valve plate was obtained,which provided a theoretical basis for the simulation modeling of the axial piston pump with conical cylinder.Secondly,through the secondary development of AMESim,the original cylinder block module was improved,and the simulation model of axial piston pump with conical cylinder block was established considering the influence of leakage.The experimental platform was built to verify the correctness of the simulation model of the axial piston pump with conical cylinder.The results indicate that: with the increase of swash plate angle,the pressure in the cavity increases and the pulsation rate decreases;with the increase of bulk elastic modulus of oil,the maximum pressure in the cavity increases,and the fluctuation rate decreases from 0.6% to 0.34%;with the increase of the dynamic viscosity of the oil,the maximum pressure in the plunger chamber increases and the pulsation rate increases slightly.Finally,in order to obtain the real value of the cavity pressure of the piston pump,the accuracy of the simulation model would be improved and the cavity pressure characteristics would be studied more intuitively.Combined with the structure and working characteristics of the axial piston pump with conical cylinder body,the pressure measurement system of piston pump cavity was designed.The ADC data acquisition program,DMA transmission mode,transplantation of FAT file system and software program design of bottom driver of cavity pressure acquisition system were written in detail.The experimental data of the pressure acquisition system was collected.The analysis of the data showed that the feasibility and stability of the pressure acquisition system were well tested.In this paper,AMESim simulation software was used to establish the simulation model of the conical cylinder axial piston pump,which provided an improved method for the establishment of the simulation model of the conical cylinder axial piston pump.On this basis,the relationship between the pressure in the cavity and the compressibility and viscosity of the oil was studied.The pressure acquisition system in the cavity of axial piston pump with conical cylinder was designed,which laid a foundation for the later research.