Analysis Of Controllable Pitch Propeller Hvdra-Ulic System And Development Of A Large Flow Rate Two-Way Lock Valve

Controllable pitch propeller(CPP)is widely used as a ship propeller.Compared with fixed pitch propeller,CPP has better mobility,maneuverability and adaptability,and improves the efficiency of ship propulsion.Hydraulic system is the core component of CPP system,its function is to provide the hydraulic oil of required pressure and flow rate to the pitch cylinder.Now the CPP system is tend to be large horsepower,light weight per unit power,small size,simple and reliable,easy to manipulate,which re-quires that the hydraulic system must have the following characteristics:high pressure,large flow rate,high efficiency,high integration and durability,etc.This thesis took the controllable pitch propeller hydraulic system of a certain type of ship as research object.Three different types of controllable pitch propeller hydraulic system(digital switching hydraulic system,electro-hydraulic proportional system with two-way lock valve,and electro-hydraulic proportional system with balancing valve)were proposed on the basis of literature at home and abroad and the develop-ment status of controllable pitch propeller.This thesis built the simulation models based on AMESim and got each system’s pitching performance and their advantages and disadvantages,put forward the corresponding improvement measures.This thesis also designed a large flow rate two-way lock valve with safety relief valve module for the controllable pitch propeller hydraulic system.Through digital computing and sim-ulation analysis,some key structural parameters of the valve were optimized.Besides,the thesis conducted an experiment,compared the experiment results to the simulation results and obtained conclusions.Contents of each chapter are listed as follows:The first chapter introduced the principles,characteristics,basic components,and the development status and trends at home and abroad of controllable pitch propeller;de-scribed structures,types and the main features of the controllable pitch propeller hy-draulic system,highlighted the two-way lock valve,balancing valve and other key components of the hydraulic system,analyzed several typical controllable pitch pro-peller hydraulic system and listed the advantages and disadvantages.The second chapter conducted load anlysis for the system and obtained load cycle diagram;analyzed the control strategy and established mathematical models of the important components of the hydraulic system,laid a theoretical foundation for the establishment of the simulation model and simulation analysis.The third chapter identified the basic parameters of a certain ship controllable pitch propeller hydraulic system;established the simulation models of different types of controllable pitch propeller hydraulic system(including digital switch hydraulic sys-tem,electro-hydraulic proportional system with two-way lock valve,and elec-tro-hydraulic proportional system with balancing valve)based on AMESim;conduct-ed simulation analysis and obtained the performances of different types of system and their advantages and disadvantages,provided a reference for the final selection of the controllable pitch propeller hydraulic system.The fourth chapter described the design requirements and principles of the large flow rate two-way lock valve;established simulation models of the large flow rate two-way lock valve(with safety relief valve module)and controllable pitch propeller hydraulic system;optimized the key structural parameters of the valve through simulation anal-ysis;completed the design of the large flow rate two-way lock valve.The fifth chapter developed the test outline of the large flow rate two-way lock valve and built the test system;obtained the flow rate-pressure characteristics and the opening and closing performance of the valve through testing;verified.the correctness of the design and simulation by comparing the testing results with the simulation re-sults.The sixth chapter summarized the research work and the results achieved of the en-tire thesis,and pointed out the direction for further research.