Design And System Analysis Of Micro Pump In AUG Buoyancy Regulation System

In recent years,countries have launched fierce competition around issues related to ocean.As a new type of ocean exploration equipment,Autonomous Underwater Glider is one of the important manifestations of competitiveness.Buoyancy regulation system is an important part of underwater glider,and it is also the bottleneck which restricts the development of profile motion platform in China.As the core of the buoyancy regulation system of Autonomous Underwater Glider,the development trend of micro axial piston pump is miniaturization,lightweight and high pressure.At present,there is a certain gap between domestic micro pump products and foreign countries’ s,and the technical indicators are difficult to reach the same level.In this thesis,a new micro axial piston pump with combined flow distribution is designed to meet the requirements of miniaturization,large submergence,long endurance and high control accuracy of underwater glider.The main research contents of this thesis are as follows:(1)In this thesis,the structural type of the pump is determined by analyzing and comparing the design structure of the micro axial piston pump of the buoyancy regulation system of the underwater glider abroad.Then the key parts of the pump,such as piston,sliding shoe,cylinder block,return mechanism and swashplate shaft,are designed and calculated.Finally,the relevant optimization design method is used to miniaturize the key parts to reduce the axial and radial dimensions of the pump.(2)Structural static analysis of the key parts of the pump,such as piston,sliding shoe,cylinder block,return pressure plate and swashplate shaft,are carried.Then the stress and strain of parts with different materials are analyzed and compared.Finally,better materials are selected to reduce the weight of the pump on the premise of ensuring that all parts meet the requirements of strength,stiffness and friction pair.(3)Compared with the characteristics of common structural types of valves and combined with the structure of pump,the delivery valve is designed.Then the hydraulic models of single plunger and whole pump are built by AMESim,and the structural parameters of the oil suction groove on the swashplate shaft are determined.Finally,the effects of clearance volume,working pressure,rotating speed and parameters of the delivery valve on the flow distribution character ristics are analyzed,and the flow pressure characteristic curve of the pump is obtained.The results show that the lag effect on the delivery valve can be reduced by reducing the clearance volume,reducing the working pressure,reducing the rotating speed,reducing the vlave spool mass and increasing the preload.the pump can have better volumetric efficiency under standard working conditions.(4)According to the working principle of the pump,the relevant mechanical loss and volume loss of the pump are analyzed,and the efficiency characteristic model of the pump is established.Then the effects of speed,load pressure and temperature on the pump efficiency are studied because of the working environment of Autonomous Underwater Glider with variable temperature and pressure.Finally,the efficiency of the pump under different working conditions is analyzed.The results show that the speed has a greater impact on the efficiency of the pump than other factors.It provides a reference for ensuring the high efficiency of small displacement pump.