Abstract：Recent advancements of wireless sensor and low power microelectrics make a great contribution to intelligent and networking health monitoring technologies. Due to key component of rotating machinery, bearings play a significant role on keeping the health state of defense, railway and wind turbines equipments. Therefore, miniaturization and self-powered methods of bearing state monitoring are important enabling technologies. This paper presents a radical electromagnetic rotating energy harvester for bearing condition monitoring to solve the power resource of wireless sensor node in the future and then introduces the circular Halbach array to improve the magnetic field of coils for performance enhancement. Based on the magnetic charge theory and space coordinate transformation, the calculation method of radial magnetic field distribution for circular Halbach array is proposed. Then the model of output voltage of the proposed energy harvester is established by electromagnetic induction. Moreover, the effect of different parameters on output voltage is numerically investigated by the proposed theoretical model. Finally, finite element simulation and experimental results under different speeds demonstrate the effectiveness of proposed model and that the proposed device can obtain the maximum output power of 81.2mW at 1000rpm.
2019, Vol. 40 
