Research On Swash Plate Miniature Fixed Displacement Axial Piston Pump

With the development of modern industry,the axial piston pump,which is the key power element in the hydraulic system,is developing in the direction of miniaturization and high pressure.The demand for miniature axial piston pumps in the robotics and oil drilling industries is also increasing.However,there is less research on miniature axial piston pumps.In this thesis,the design,theoretical analysis,simulation optimization and experimental research of the swash plate miniature fixed displacement axial piston pump are carried out.First of all,in order to maintain the space and weight requirements,a comprehensive comparison of the structure and characteristics of a series of plunger pumps are completed.The results show that the combined distribution method of the swashplate and the valve is able to meet the requirements.Based on the kinematics and dynamics analysis of the plunger and the slipper design are completed.At the same time,the key components such as the return mechanism of the plunger,the swash plate and the spindle are also analyzed and simulated.The 3D model of the entire pump is constructed through Solid Works,and the interference check is done.Secondly,both the theoretical and CFD simulation are carried out for the key friction pair of the small plunger pump.The leakage model and the effects of various factors on the leakage flow are obtained and analyzed.The thermodynamic simulation of the plunger and the cylinder are performed using ANSYS software package considering the actual working conditions.The film thickness between the plunger and the cylinder bore is obtained.And the leakage between the cylinder and the plunger is also obtained which is consistent with the theory result.The fluid flow characteristics at the slipper are studied based on the control equations of the residual pressing force design method.The film thickness and the leakage between slipper and the swashplate are both obtained.Next,in order to study the valve distribution mechanism of the micro piston pump,an AMESim model is built.The influence factors of the lag angle and the closing lag angle of the distribution valve are simulated and analyzed.According to the simulation results of the pressure flow characteristics,the parameters of the principle prototype of the micro-piston pump are optimized,and the design of the swash plate distribution groove is completed.Finally,the principle prototype of the micro piston pump is manufactured,and the test bench is set up.The test results not only verify the correctness of the flow distribution method and the structure design of the micro-piston pump,but also provide the direction for the next step in the research of the small axial piston pump.In this thesis,a miniature piston pump is designed by adopting joint flow distribution,The theoretical analysis and simulation optimization of the piston pair,sliding shoe pair and flow distribution valve inside the miniature piston pump were carried out.The loss of volumetric efficiency at these three critical locations was analyzed.The principle prototype of the miniature piston pump is designed and manufactured.The feasibility of the structure design of the miniature piston pump is verified by experiments.The research in this thesis is beneficial to the miniaturization development of the swashplate axial piston pump.