面向智能轴承自供电系统的压电-摩擦复合式振动能量采集器

Hybrid Piezoelectric-Triboelectric Vibration Energy Harvester for Intelligent Bearing Self-Powered System

针对智能轴承外圈径向开槽结构中以电池供能的状态监测设备存在应用场合受限的问题,提出了一种适用于智能轴承自供电系统的压电-摩擦复合式振动能量采集器。该能量采集器以带双质量块的三角形单晶压电悬臂梁为基础,在悬臂梁的振动方向上有机集成兼具限位功能的摩擦纳米发电机,实现了振动和限位碰撞过程中压电-摩擦电两种模式的复合协同发电,有效利用了空间并提高了输出性能。同时,利用集中参数法建立了能量采集器的机电耦合动力学模型,通过COMSOL软件分析了不同结构与尺寸对压电悬臂梁固有频率和输出电压的影响,并通过试验验证机电耦合动力学模型与仿真分析的准确性。试验结果表明:所提能量采集器能够在0~28.2 m/s^(2)的智能轴承正常工作振动加速度范围内有效工作;在加速度为2 m/s^(2)时,该采集器的压电和摩擦电单元开路输出电压最大峰峰值分别可达1.28 V和1.05 V;在加速度为20 m/s^(2)时,该采集器的压电和摩擦电单元开路输出电压最大峰峰值分别可达2.85 V和1.18 V。

A hybrid piezoelectric-triboelectric vibration energy harvester for the intelligent bearing self-powered system is proposed for the problems of limited applications of battery-powered condition monitoring devices in the radially slotted outer ring structure of the intelligent bearing.The energy harvester is based on a triangular single-crystal piezoelectric cantilever beam with double mass blocks,and two nanogenerators with limiting function are organically integrated with the vibration direction of the cantilever beam.The composite co-generation of piezoelectric and triboelectric modes during vibration and limit collisions is realized.The space is effectively utilized and the output performance is improved.Meanwhile,the electromechanical coupling dynamic model of the energy harvester is established by using the centralized parameter method.The effects of different structures and sizes on the natural frequency and output voltage of the piezoelectric cantilever beam are analyzed by COMSOL software.The accuracy of the electromechanical coupling dynamic model and simulation analysis are verified by experiments.The test results show that the proposed energy harvester can work effectively in the range of 0~28.2 m/s^(2) of the normal working vibration acceleration of intelligent bearing.At an acceleration of 2 m/s^(2),the maximum peak-to-peak values of the open-circuit output voltages of the piezoelectric and triboelectric units of the harvester are 1.28 V and 1.05 V respectively.At an acceleration of 20 m/s^(2),the maximum peak-to-peak values of the open-circuit output voltages of the piezoelectric and triboelectric units of the harvester are 2.85 V and 1.18 V respectively.