Structural Optimization And Experimental Study On The Properties Of Friction Pairs In Axial Piston Pump

For almost all of the variable displacement machines, including axial piston pump, the gaps of friction pairs between moving parts and relatively static ones are always essential elements in the design and optimization. As the core of power components in hydraulic system, axial piston pump is widely used in industrial hydraulic equipment and mobile machinery. With the performance requirements of hydraulic components increasing in industry field, especially the development trend towards high pressure, high flow and low noise, the improvement of working life and performance in axial piston pump has been the design and optimization goal. Friction pairs have vital influence on the working life and reliability of axial piston pump while running.In this thesis, the design of the test structure was optimized and some experimental study was done for investigating the properties of friction pairs in swash plate axial piston pumps based on the model pump theory. The main content of this thesis is divided into five chapters, as following:In chapter 1, the axial piston pump, the properties of friction pairs and the existing test methods were introduced. The research status and results of investgating the properties of friction pairs by institutions at home and abroad were presented, and the significance and contents of this thesis were given out.In chapter 2, beginning with the overview of the model pump and the test programs of pressure field and friction forces in piston pair, the test programs were optimized according to the completed test. The structure of coating on the cylinder was optimized, and the shell was redesigned due to the difficulties in assembling the model pump and the influence by expanding the cylinder size. Meanwhile, according to the relationship between shell and other relevant parts, the structure and installing places of related parts were redesigned or changed. The manual variable institution was redesigned to ensure the model pump to achieve variable function, and the strength of the key part was checked when completing.In chapter 3, the test program for investigating the temperature distribution of piston pair was overviewed, and then the field was described numerically. After improving the fixing structure of thermocouple and completing the test procedure interface, experimental analysis was carried out for the distribution of temperature field of the piston pair.In chapter 4, the test programs were designed for the temperature distribution and thickness variation of oil film in the valve-plate/cylinder pair. The installing structure on the test rig was designed, choosing the axial piston pump with planar valve-plate structure as model pump. The test programs were given out, as well as the selection of test components, the structural design of key components, and data acquisition system, and the influence by mounting holes of the sensors was analyzed.In chapter 5, the summary of the whole work and the prospect in the future are proposed.