Investigation Into The Performance Of Hydrostatic Support Column Pair Of Radial Piston Pump

With the industry technology developing, hydraulic transmission becomes one of the technologies developed quickly in the mechanism equipments, especially in the latest year. As a key part of the hydraulic system, hydraulic pump plays such an important role that its performance exerts direct influence upon the reliability of the whole hydraulic system. Owing to the cylindrical surface of piston and jar hole, radial piston pump can be assembled accurately. Compared with the axial piston pump, the radial piston pump is better against impact, moreover, it has longer life, higher cubage efficiency and higher control precision. Since 1990, many research organizations and factories have been engaged in the research on radial piston pump in our country, but their efforts resulted badly. The main difficulty lies in solving the problem of the friction between rotor and oil axis, slipper and stator.In this paper, a new radial piston pump is brought out. The traditionalstator-piston is replaced by rotor-piston in this pump. The both propertiesof static state and the dynamic of the oil-film of this friction pair areanalyzed.The main contents dealt with in this thesis are following:1 .The kinematics of radial piston pump including the movement ofpiston relative to jar and that of roller relative to piston.2. The received forces of the piston and the roller were analyzed. The bearing force of the stator, the positive pressure and the friction between the jar hole and piston were simulated.3. There are some researches on the static state property of the column pair based on the hydrostatic bearing, including support force, support property equation, stiffness property and static balance equation.4. The calculation formula of the extrusion bearing force of the column pair was educed, so as to be ready for dynamic simulation of the oil film of the column pair based on hydrostatic support. The dynamic equation of the oil film on the column pair was established. By application of the SIMULINK toolbox of MATLAB, the simulation models were obtained.5. The derivation of the leakage flow rate formula of the special annular clearance between the piston and cylinder under the condition of variable viscosity in the radial piston pumps was carried out, at same time, considering the questions of the eccentricity and the variable sealing lengthof piston friction pair, and the modified coefficient of the calculation formula of the flow-rate of the leakage was given.