An electromagnetic energy harvester for rotational applications

Many industrial applications incorporate rotating shafts with fluctuating speeds around a desired mean value. This often harmonic component of the shaft speed is generally undesirable, since it can excite parts of the system and can lead to large oscillations (potentially durability issues), as well as to excessive noise generation. On the other hand, the addition of sensors on rotating shafts for system monitoring or control poses challenges due to the need to supply power to the sensor and extract data from the rotating application. In order to tackle the requirement of powering sensors for structure health monitoring or control applications, this work proposes a nonlinear vibration energy harvester design intended for use on rotating shafts with harmonic speed fluctuations. The essential nonlinearity of the harvester allows for increased operating bandwidth, potentially across the whole range of shaft's operating conditions.