Sdudy Of Lubrication In The Spherical Port Plate Pair Of Axial-Piston Pumps

Hydraulic axial piston pump has been commonly used in the majority of fluid power applications for specific advantages such as compact dimension,high power density and long lifecycle.However,excessive weal"and intemal leakage have adverse effects on the volumetric efficiency and life expectation of piston pump,which are mostly determined by the operating condition of three critical tribo—pairs inside this type of pump,especially the characteristics oflubricating oil film within each moving tribo-pair.As its great importance and complicated mechanism,the oil film in axial piston pump has been a frontier research topic in the field of fluidp ower transmission and contr01.Therefore,the oil film characteristics within the barrel-port plate,one of three critical tribo-pairs,were investigated in this thesis,which could be used as aspecific theoretical reference to design a new generation of axial piston pump.In thepaper,researching lubrication of port plate/cylinder block friction pair is the main object. The main achievements include the contents as follow. The mathematic model of lubrication ofport plate/cylinderblock frictional pair was established.The formation ofthelubricating film thickness is described through the theory models.The formation of the lubricating film thickness was researched and simulated. The influence ofworking pressure, temperature, rotating speed and structure on the lubrication can be researched through simulation.When other working condition is invariable,the lubricating film thickness decreases as the oil pressureor oiltemperature increases.The filmforms fast as the oil pressure increases.The main contents of the article as follows:Firstly, Spherical distribution of the axial piston pump Lubrication flow damping tank pressure - flow characteristics, squeeze film theory, film theory of hydrostatic bearing, hydrostatic bearing hot wedge the basic theory of film theory. These theories benefit spherical distribution pairs mathematical model.Secondly, Established a spherical distribution pairs of the physical model, the leakage model and the mechanical model. These models describe the distribution pairs for the lubricating film between the changes of the movement, can be drawn is contained in the applied force on the valve plate and the distribution pairs between film thickness, which can simulate the spherical distribution pairs formation and variation of film .Finally, CFD three-dimensional fluid analysis software used to establish a flat distribution pairs and spherical distribution pairs of the two analytical models under different conditions. Comparison of two distribution pairs film body pressure, temperature and velocity field. The results show that, in the same condition, the spherical distribution pairs the lubrication properties of the flow field is significantly better than the flat distribution pairs. Based on the above analysis, the spherical valve plate on the structure optimization, the establishment of a spherical distribution pairs optimal design model, the optimization model can be taken in a very short period of time get a group meet and the force balance and torque balance and small amount of leakage Performance of the optimal structure parameters.