| Hydraulic pump is a kind of energy conversion device,which is the key component of hydraulic system.Its function is to convert mechanical energy into liquid pressure energy,and the reliability of the whole hydraulic system often depends on the performance of the hydraulic pump.Because the radial piston pump has the advantages of high working pressure,impact resistance,long service life,and high control precision compared to the axial piston pump,it is used as a new type of high efficiency and energy saving hydraulic pump and has been widely used in mining machinery,lifting machinery and forging machinery hydraulic systems.The research on the oil film characteristics of the slipper pair will help the design and optimization of the friction pair,so as to improve the life,efficiency and reliability of the hydraulic pump.In this paper,a new type of radial piston pump named JBP-40 as the research object,based on the analysis of the movement and force of the slipper pair of piston pump,the optimum theoretical value of the oil film thickness under the principle of hydrostatic bearing about the slipper pair in friction pair is obtained by theoretical calculation,and establish the dynamic characteristic equation of oil film.The Simulink software was used to simulate the oil film characteristics of slipper pair under different pressure and rotational speed,and the change law of oil film thickness under different pressure,different rotational speed,different temperature and different structure size of Slipper pair was obtained.At the same time,the piston pump on the drilling jumbo is analyzed under the impact of the high frequency impact mechanism,and the change law of the oil film thickness fluctuation is obtained by changing the pressure of the central oil chamber under the variable load,the oil film thickness with time fluctuation curve and the pressure wave period and the high pressure time duration.Finally,it is indicated that the radial piston pump is more advantageous than the axial piston pump which is used in drilling jumbo.The main contents of this thesis are as follows:1.The research background and significance of this subject are discussed,and the research status of piston pump slipper pair at home and abroad is investigated.On the basis of this,the emphasis of this paper is made clear.2.The working principle of radial piston pump and kinematics analysis of slide shoe pair are introduced.It also explains how to make the gap oil film with pressure feedback and preliminary calculation of the structural size of the static pressure bearing shoe pair.3.The static characteristics of the hydrostatic bearing slipper pair were studied,and the variation law of the optimal oil film thickness was obtained.The equation of the dynamic characteristics of the secondary oil film of the shoe is deduced on the condition that the load pressure rises steadily.The SIMULINK in MATLAB is used to simulate the dynamic characteristics of the gap film.4.Simulation analysis of check valve opening characteristic,piston displacement curve and pressure fluctuation curve in rock drilling trolley impact system.The model of oil film thickness under high frequency variable load is built by using pulse pressure wave.The variation process of oil film of slipper pair under variable load is studied.5.The formula for calculating the leakage flow of the variable viscosity sliding shoe pair was deduced and compared with the flow formula with the same viscosity. |
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