| Human developments of ocean activity are more frequently under sea from shallow sea to deep sea.Working devices of deep sea are facing great challenges of high pressure, low temperature and corrosion. Hydraulic power source influences the device system performance and reliability as the heart of power source.The development of deep-sea hydraulic power source is still at initial stage in China. The existent problems are invariable control, low system efficiency, difficulty to control remotely, low interchangeabilities, low adaptability, lacking of general deep-sea technologies, special standards and serial products.The deep-sea electro-hydraulic proportional source is studied, and a sample is made which can be used at 3000 meter deep-sea.lt focuses on the design of the overall program, solutions of key technologies, research on control characteristic and tests in deep-sea simulation hull. The main contents are as follows.1. Against the affects of deep-sea environments, it drafts the overall study program of hydraulic source and implementation plans, and complets the design of the entire layout. By the decomposition of the system, the main contents of the dissertation are proposed. A discussion of correlated theoretical knowledge and experimental equipmen is sure of the study work executed smoothly,2. The hydraulic components are immersed in an oil reservoir in order to adapt the sea-water pressure. The internal and external pressures of the reservoir are balanced by the volume change of a theca pressure compensator connected with the reservoir. The analysis of static and dynamic property of the reservoir system is done. A design guideline is proposed for the oil reservoir system stability to analyze performance of dynamic compensating characteristic with variable structure parameters, and the rule is validated it by experiment tests. Considering detection features of hydraulic pump pressure in sub-sea, a self-adaptive detection technology based on dual pressure sensors is also proposed to elimnate the affect of sea-water pressure. By research on undersea pressure self-adaptive detection, design and application, the engineering prototype is developed, and then related experiment is studied.The results show:the prototype has a good environmental adaptability and satisfies the requirements for pressure control of the hydraulic pump. A light pressure-proof shell is designed, the analysis of the shell for electronic components is carried out by finite element analysis software, and tests displays it can work well in 3000 meter deep-sea,3. By analyzing the properties changing of oil media under deep-sea environment, and leading into dynamic expression equation of the changing of effective bulk modulus (compression) and viscosity of hydraulic oil, a transfer function and the static characteristic equation of proportional valve are established. The influences of environmental factors, lubrication condition and structural parameters to the valve control characteristics are stuted. Based on the varying environment feature of deep-sea work conditions, considered oil property varying, applied the theory of linear varying parameter (LPV), the LPV model of proportional variable pump system is created. By simulation analyses, it obtains the control characteristics and the changing trends of the hydraulic pump system in bounded closed set of varying parameters. The results show that the pump dynamic responses become slower and the steady-state output value keeps invariable, with the environment pressure increasing and work temperature decreasing, which coincide with the experimental results. At the same time, it displays the methods of high quality and low viscosity oil media, low viscous damp system and variable gain adjustment benefit to the working performance to be steady for hydraulic sources in deep sea.4. It verifys the pressure adaptability of components for hydraulic power source, by pressure-proof tests of pressure-balanced oil reservoir, self-adaptive pressure detection equipment and pressure-proof shells, and analyzes pressure-proof property, control characteristic and dynamic responses of the proportional pressure valve by tests in deep-sea simulation hull. The characteristics of the close-loop controlled variable pump are acquired at different pressure, by pressure-proof test, steady-state control test, dynamic property test and frequency response test in the deep-sea simulation hull. The result of system integration and debugging of electro-hydraulic proportional hydraulic power source shows:the entire system works steadily, and the system output responds quickly with good following performance. The experimental results of each parts and systems verify that theoretical analysis conclusions are reasonable and the developed proportional hydraulic power source can be well suitable for deep-sea 3000 meter environment.The thesis lays a great theoretical and technological basis for deep-sea hydraulic power source system, and provides application research foundation for the overall design of hydraulic systems in deep-sea detection equipment.
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