Research On Flow Field Simulation And Working Characteristics Of Asymmetric Axial Piston Pump

The asymmetric axial piston pump is the core component that provides power for the pump-controlled asymmetric hydraulic cylinder system.It has the advantages of compact structure,large flow,high pressure,and high power.The pump-controlled asymmetric hydraulic cylinder system is used in construction machinery and aircraft industry.Widely used in other fields,the performance of the asymmetric axial piston pump directly determines the reliability of the pump-controlled asymmetric hydraulic cylinder system.The asymmetric axial piston pump will produce flow pulsation during the working process,which will seriously affect the performance of the asymmetric axial piston pump.With the development of hydraulic transmission technology,the pump-controlled asymmetric hydraulic cylinder system will affect the asymmetric shaft.Higher requirements are put forward for the performance of the plunger pump.Therefore,it is urgent to carry out research on reducing the flow pulsation of the asymmetric axial plunger pump.This paper takes a high-speed asymmetric axial piston pump for aviation as the research object,uses simulation technology to analyze the influence law of working condition parameters and flow ratio on the flow characteristics,and provides a theoretical basis for reducing the flow pulsation of the asymmetric axial piston pump.First,compare and analyze the characteristics of series and parallel valve plates.Based on the series valve plates,design and use three-dimensional modeling technology to establish and parameterize the static fluid domain geometric model of the two-way valve plate,and use the Design Modeler module to use the method of extracting the fluid domain.The geometric model of the plunger cavity is established,and the geometric model is divided by the Meshing module using structural and unstructured meshing methods,and the finite element model of the entire pump is established.Secondly,use dynamic grid technology(UDF)to simulate the reciprocating movement of the plunger,use sliding grid technology to simulate the rotation of the plunger,use CFD technology to simulate and analyze the influence of working condition parameters on flow characteristics,and combine the flow field velocity at the transition zone position The vector diagram reveals the relationship between flow field changes and flow characteristics.The research results show that with the increase of load pressure,the displacement of the load port gradually decreases,and the flow pulsation gradually increases;with the increase of the spindle speed,the flow rate of the suction and discharge ports gradually increases,and the flow pulsation gradually decreases.Trend,but the reduction is smaller.Finally,use the parametric modeling method to establish the finite element model of the asymmetric axial piston pump with port A and B port ratios of 1:0.2,1:0.3,1:0.4,1:0.5,and analyze the theoretical wrap angle of the port The reason for the error of the actual wrap angle is to analyze the influence of the flow distribution ratio on the flow characteristics,and analyze the change law of the flow characteristics in combination with the flow field of the flow distribution.The research results show that: during forward rotation,the actual flow of port A is less than the theoretical flow,and the actual wrap angle of port B is greater than the theoretical wrap angle.With the increase of the flow ratio,the discharge port flow gradually increases,and the flow pulsation gradually decreases;When the actual flow of port B is greater than the theoretical flow,the actual wrap angle of port B is less than the theoretical wrap angle.With the increase of the flow ratio,the discharge port flow and flow pulsation did not change significantly.The method of increasing the flow ratio can effectively reduce the flow pulsation.