Study On Characteristics Of Oil Film For Slipper Pair Of Axial Piston Pumps

Axial piston pump is through the reciprocating motion of the piston to achieve oil suction and extrusion. Slipper pair is the joint between piston and swashplate. In addition to axial force from the plunger cavity high pressure oil, the slipper is also under the effect of the torques because of slipper's centrifugal movement and friction between swashplate and slipper rotating with cylinder, which will have an effect to make sealing surface of the slipper and swashplate surface produce a certain angle. Because of slipper oil film pressure field, elastic deformation also occurs in the slipper sealing surface. Then wedge! oil film will form, which makes slipper pair oil film thickness-field become complicated.Axial piston pump slipper is not in accordance with the design method of hydrostatic bearing design. By using the principle of three points defining a plane, the model of oil film thickness-field is built. Analyzing the oil film pressure-field of the overturning slipper, this thesis finds that slipper bottom surface "concave" structure can help slipper's posture self-adjustment. Based on this analysis, this thesis proposes a kind of optimized slipper structures against overturning. It is proved that optimized slipper have better performances in slipper's overturning extent, stability and the minimum film thickness.In chapter 1, the overview of axial piston pump friction pads was introduced, especially for Slipper pair. The domestic and foreign research progress on slipper lubrication research was reviewed. The main research content and ideas were identified and the difficulties of this study were also presented.In chapter 2, modeling was built for the Force and motion equations of Slipper,and do some research on the Slipper elastic deformation under oil film pressure field of slipper pair.In chapter 3, modeling was carried out for flow-pressure negative feedback regulation system composed of fixed damping and variable damping of hydrostatic slipper pair bearing. This was taken as boundary condition for researching the coupling relationship between the force/torque exerted on the slipper and the model of slipper pair overturning oil film. Finally, through Matlab programming, the simulation model of slipper pair oil film coupling relationship was built.In chapter 4, propose a kind of optimized slipper structures against overturning which can improve slipper pair oil film pressure-field. It was verified by experiment from the point of slipper wear.In chapter 5, In order to verify the simulation results, a test rig for slipper pair oil film oil film thickness-filed was designed and engineered.In chapter 6, conclusions in this thesis were summarized and future research proposals were suggested.