无轴轮缘推进器用橡-塑多层复合材料水润滑径向轴承流固耦合润滑承载机理研究

Water-lubricated bearings are the key support components of shaft-less rim-driven thrusters (RDT). Their lubrication and load-carrying properties directly affect the running performance and service life of RDT. Due to the limitation of material properties, traditional water-lubricated rubber bearings and plastic bearings can not meet the requirements of RDT water-lubricated bearings for both good lubrication performance and good damping performance. Formed by superposing rubber and plastic, the rubber-plastic multilayer composite water-lubricated bearing can combine the advantages of rubber and plastic to obtain superior performance. Therefore, this project takes nitrile rubber-polytetrafluoroethylene multilayer composite water-lubricated journal bearing for RDT as the research object. Considering the effects of elastic deformation of bush, journal misalignment, flow state and cavitation of lubricating film and other factors, the fluid-structure coupling numerical methods for calculating static and dynamic characteristics of the bearing are developed. The simulation analyses and experimental researches on static and dynamic characteristics of the bearing are carried out. The characters and rules of bush deformation under film pressure are analyzed. The influences of operating condition and bearing structure on the static and dynamic characteristics of the bearing are studied. The influence mechanism of the complex bush deformation on the static and dynamic characteristics of the bearing is revealed. The research achievements can provide theoretical support for the design and application of rubber-plastic multilayer composite water-lubricated bearings for RDT, and have important academic and practical engineering guide significance.

水润滑轴承是无轴轮缘推进器（RDT）转子的关键支撑部件，其润滑承载特性直接影响RDT的运转性能和使用寿命。受材料性能的限制，传统的水润滑橡胶轴承和塑料轴承通常无法同时满足RDT水润滑轴承对良好摩擦润滑性能和良好阻尼性能的要求，而将橡胶和塑料叠加形成的橡-塑多层复合材料水润滑轴承能够综合两者的优点，获得更优越的性能。因此，本项目以RDT用丁腈橡胶-聚四氟乙烯多层复合材料水润滑径向轴承为研究对象，考虑轴瓦弹性变形、轴线倾斜、润滑水膜的流动状态及空化等因素的影响，通过开展该种轴承的静动特性流固耦合数值计算方法研究、静动特性数值模拟分析和实验研究，分析该种轴承在水膜压强作用下的轴瓦变形特点和规律，研究运行工况和轴承结构对该种轴承静特性和动力特性的影响规律，揭示复杂轴瓦变形对该种轴承静动特性的影响机理，为RDT用橡-塑多层复合材料水润滑轴承的设计和应用提供理论依据，具有重要的科学意义和工程应用价值。

无轴轮缘推进器（RDT）通过电机定子和转子间的电磁力直接驱动螺旋桨，具有结构紧凑、推进效率高、振动噪声小、维护方便等优点，在军事、民用领域都有十分广阔的发展前景。橡塑多层复合材料水润滑轴承能够综合橡胶阻尼性能好和塑料摩擦性能好的优点，提高RDT的推进效率，降低振动噪声。但目前橡塑多层复合材料水润滑轴承的润滑承载机理尚不明确，制约了该种轴承的发展和应用。本项目研究RDT用橡塑多层复合材料水润滑径向轴承的流固耦合润滑承载机理，从流固耦合数值计算方法、润滑承载特性数值模拟分析和实验研究等方面开展工作。主要研究成果包括：①考虑轴瓦弹性变形、水膜流动状态和空化等因素，建立了水润滑径向轴承流固耦合（FSI）润滑模型，利用单向FSI研究了轴瓦的变形特点和规律，采用双向FSI仿真计算了轴承的润滑承载性能，并与塑料轴承和橡胶轴承性能进行了对比，揭示该种轴承的润滑承载特点；②针对软件FSI模型网格易产生畸变的问题，采用编程方法建立了双向FSI模型，仿真分析轴承运行工况和结构参数对橡塑双层复合材料水润滑轴承润滑承载性能的影响规律，揭示轴瓦变形对该种轴承润滑承载特性的影响机理，并形成了该种轴承结构参数设计方法；③开发了橡塑多层复合材料水润滑轴承制备方法，确立了水润滑轴承摩擦系数、水膜厚度、偏心率及动力特性的测试方法，对不同结构水润滑轴承进行性能测试，验证了理论结果的正确性。以上研究成果为RDT用橡塑多层复合材料水润滑轴承的设计和应用提供理论依据，具有重要的科学意义和工程应用价值。