水润滑橡胶轴承全息水膜压力无线传感在线监测及其润滑机理

Film pressure is the important parameter of water-lubricated bearing, and the significant characteristics of bearing can be adopted by in-depth study on film pressure. But the implementation and development about monitoring on film pressure is restricted greatly because of the leakproofness of film pressure existential space, the complexity of film pressure existential region and the limitations of existing monitoring methods (the distribution information of water film in global field can not obtained, larger measuring error is existed, etc). The new solving ideas and methods of on-line monitoring on film pressure of water-lubricated bearing is provided in the project based on wireless sensor technology, and the lubrication mechanism of rubber bearing is studied by a series of experiments. A non-invasive monitoring method is proposed, the lubricating state of bearing working interface is not damaged, the puzzles about arrangement of measurement points and installation of sensors can be solved, and the measuring accuracy can be improved. A rotating power generation method is proposed, the energy conversion and storage mechanism is studied and the puzzles about power supply of wireless devices in rotary motion can be solved. The doppler effect mechanism of wireless devices in rotary motion and film pressure loss mechanism are studied, and the reliability of monitoring system can be improved. The verification experiments are conducted on test rig of water-lubricated bearing. The holographic distribution characteristics of water film pressure for rubber bearings under typical working conditions are adopted, the existing region of water film pressure is described accurately. The research achievements have important significances to the study on lubrication theory, the motoring on operating state of water-lubricated bearing, and the bearing design and its applications.

水膜压力是水润滑轴承的重要参数，可通过对其深入研究来获得轴承的重要特性；而水膜存在空间的密闭性、存在区域的复杂性以及现有监测方法的局限性（无法获取水膜压力全域分布信息、测量误差较大等）都大大制约了水膜压力监测的实施与发展。本项目基于无线传感技术，旨在为水润滑轴承水膜压力的在线监测提供一种全新的解决思路与方法，并结合实验研究橡胶轴承润滑机理。提出一种非侵入式监测方法，可在不破坏轴承工作界面润滑状态的同时解决测点布置与传感器安装难题，提高测试精度；提出一种旋转自发电方法，研究能量转换与存储机理，解决旋转运动中无线设备的供电难题；研究无线设备在旋转运动中的多普勒效应产生机理与水膜压力的损失机理，提高监测系统可靠性。在水润滑轴承实验台上进行验证实验，获得典型工况下的橡胶轴承全息水膜压力分布特征，准确描述水膜存在区域。研究成果对水润滑轴承润滑理论研究、运行状态监测以及轴承的设计与应用均具有重要意义。

水润滑橡胶轴承因其良好的润滑与摩擦特性，在水力机械中得到了广泛应用。项目围绕水润滑橡胶轴承特性及其润滑机理展开研究，主要做了以下工作：①提出水润滑轴承水膜压力无线传感非侵入式在线监测方法。给出总体监测方案，设计水润滑轴承试验台，搭建监测系统，开发Zigbee透传无线设备。②提出旋转机械无线监测设备能量供应方法。在试验台尾部安装永磁发电机、减速机与导电滑环收集旋转机械能量，设计能量存储装置，研究能量转换与存储机理，解决无线设备能量供应问题。③研究旋转运动无线设备多普勒效应问题，并对监测系统可靠性进行评估。通过多普勒频移理论模型与试验结果分析，得到影响无线设备通信质量因素为电磁波入射角、轴转速与摆动圆直径。④研究轴承水膜压力在L型流道中的损失机理。直流道沿程与流道转折处局部压力损失研究结果表明，水膜压力损失影响因素有液体流速、轴转速、轴导流孔长度以及转轴动静态。⑤进行轴承水膜压力在线监测试验。重点研究低速、重载下的橡胶轴承全息水膜压力分布和变化规律。结果表明，凹面轴承不能形成完全润滑膜，在摩擦界面上既存在连续润滑膜又有宏观尺度接触，为混合润滑；平面轴承轴系轴心轨迹不规则且多变，不能形成连续润滑膜，为边界润滑。Streibeck曲线分析表明，加载力越大，轴旋转时偏心距越大，流体动压效应越明显。低速重载下，轴承长时间处于混合润滑状态。⑥采用多点激励单点响应法并锤击法对水润滑橡胶轴承进行振动模态试验，在频域内用集总平均法进行定阶，得到轴承模态参数。结果表明，不同工况下，轴承两端摩擦磨损与振动较大。⑦采用强流脉冲电子束技术对WC-13Ni硬质合金（轴承外壳材料）表面进行辐照改性处理，研究辐照对硬质合金组织与性能的影响，为轴承材料研究提供理论依据。⑧采用新型复合八梁结构作为传感器的敏感元件模型，研究敏感结构应力分布规律，优化了传感器信号检测电路；通过MEMS技术加工封装了传感器芯片并进行性能测试。