Optimisation of a hybrid energy scavenger with piezoelectric / magnetic coupling for sensor-bearing units

This paper describes the numerical and experimental design activity performed to optimize the layout of a new energy harvester based on the flexural vibration periodically excited by rotating permanent magnets of a cantilever with surface bonded piezoelectric layers. Test case concerns the possibility of supplying the required power to some sensors in monitored back–up roll bearings used in the rolling mill. A suitable methodology to assess the layout of the energy scavenger is discussed. Investigating the feasibility and the efficiency of this device in the contest of the proposed industrial application is a goal of the activity as well as the detection of the critical issues of the mechatronic design of the energy scavenger, being an example of multiple electromechanical coupling.