Development Of The Variable Displacement Piston Pump With Electro-hydraulic Proportional And Load-sensitive Control

Hydraulic power transmission and control technology has many advantages such as greater transmitted power, higher control precision, faster response speed, easy to realize integration of mechatronic and hydraulic control. Because of the advantages showing above, hydraulic power transmission and control system is widely used in mechatronic engineering field. As the high-speed development of modern industry, the power resource of hydraulic system -hydraulic pump was required higher and higher. And the variable displacement piston pump with electro-hydraulic proportional and load-sensitive control thereinto has been the critical component of hydraulic system which is to high pressure, high efficiency and great power density because it has advantage of saving energy which can require needs of load self-reacting in flux and pressure. Also, the engineer has paid more attentions on the energy saving, static manipulative precision, dynamic stability of this kind of variable displacement piston pump with electro-hydraulic proportional and load- sensitive control.This thesis researches on the YL-56 variable displacement piston pump with electro-hydraulic proportional and load-sensitive control. On the basis of the whole technological structure of the hydraulic control system, the structure of the electro-hydraulic proportional flow valve, the electro-hydraulic proportional pressure valve and the load-sensitive valve were designed. The thesis also constructs the simulation model of the YL-56 variable displacement piston pump which was constructed by above valves. This thesis does many analysis about static and dynamic characters of the developed electro-hydraulic proportional variable displacement piston pump with AMESim(Advanced Modeling Environment for Simulations of engineering systems). With the test-bed we design, many experiments were done on the model machine of the developed YL-56 variable displacement piston pump with electro-hydraulic proportional and load-sensitive control. From the results, we find that the coherence between the simulation and experiment. So the thesis developed the model machine of the proportionl piston pump successfully. The theory and results are useful for industrialization of this variable displacement piston pump with electro-hydraulic proportional and load-sensitive control.The main contents of this thesis are as follows:In chapter 1, it makes summarize of the development course and research actuality home and abroad of axial piston pump and variable displacement piston pump with electro-hydraulic proportional and load-sensitive control. Based on these overviews, the significance and the main research subjects are presented.In chapter 2, the structure and working principle of the YL-56 variable displacement piston pump with electro-hydraulic proportional and load-sensitive control are introduced in detail. The main construct components of the variable displacement piston pump with electro-hydraulic proportional and load-sensitive control such as the electro-hydraulic proportional flow valve, the electro-hydraulic proportional pressure valve, the load-sensitive valve and the variable displacement piston are developed.In chapter 3, it does academic analysis of the electro-hydraulic proportional flow valve, the electro-hydraulic proportional pressure valve and the variable displacement piston pump with electro-hydraulic proportional and load-sensitive control. Simulative models of electro-hydraulic proportional flow valve, electro-hydraulic proportional pressure valve and variable displacement piston pump with electro-hydraulic proportional and load-sensitive control are set up using AMESim. Then it does static and dynamic research of the flow and pressure characteristic, and discusses how hydraulic resistance influences the static and dynamic characteristic.In chapter 4, with reference to relative national standard, we designed the hydraulic test system and test-bed of the variable displacement piston pump with electro -hydraulic proportional and load-sensitive control. To do the experiments of the pump, some effective measures were proposed. Then a lot of static and dynamic character tests were done with the test-bed.In chapter 5, all of achievements of the thesis are summarized and the further research work, which will be done, is put forward.