Research On Bent Axis Type Variable Displacement Axial Piston Pump Using Kerosene As Working Medium

With the development of Chinese aerospace industry, some strict requirements, such as lightweight and integration, are raised to aerospace hydraulic equipment. Hydraulic system using kerosene as the working medium is considered to be one of the future research orientations. Axial piston pump with kerosene is an important component in aerospace hydraulic system and its life and reliability seriously impact the reliability of aerospace craft. However, the working condition of axial piston pump is greatly deteriorated due to low viscosity and poor lubricity of kerosene. Since kerosene axial piston pump is related to military fields such as aerospace and aviation, its research has been restricted by technical blockage abroad. To develop this axial piston pump with independent intellectual property has important significance.On the basis of extensive research on the relevant documentations and products, a bent-axis type variable displacement axial piston pump using kerosene as working medium is designed in this thesis. Design theory of the traditional hydraulic oil axial piston pump is used as foundation, and develop train of thought of axial piston pump using other low viscosity medium is also referenced. According to the characteristic of kerosene, key technologies on the designing of kerosene axial piston pump is discussed, including aspects of structural types, motion analysis, pressure flow characteristics, rotary sealing, and bearings of the pump.According to the technical requirements of the pump and characteristics of kerosene, key technologies on the designing of kerosene axial piston pump is discussed. On the basis of kinematics and kinetic analysis of bent-axis type axial piston pump, its flow and leakage model are carried out. After the main structure parameters are determined, the friction pairs material matching scheme is proposed based on PV values of different motion pairs. Specific to high speed and high sealing pressure requirement of kerosene axial piston pump, a mechanical seal is introduced. A new variable displacement mechanism is designed and its flow characteristics are analyzed. A hydraulic transformation model of kerosene axial piston pump is built based on the bond graph theory. In order to predict the volume efficiency of kerosene axial piston pump, the impact of different structure parameters on the pressure flow characteristic and leakage characteristics are carried out. The clearances of different friction pairs are given and the efficiency of the designed kerosene axial piston pump is predicted.