Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : March 14, 2018 - March 15, 2018
This paper proposes a novel design of a magnetically-sprung mechanical oscillator using ring magnets for use in electromagnetic wideband vibration energy harvesters. In the proposed design, two fixed ring magnets are placed to hold a moving cylindrical magnet in the middle whose diameter is smaller than the bore of the ring magnet, guided to smoothly move along the axis direction. Thanks to the offset magnetic pole of the ring magnet from that of the moving magnet, the repulsive force acting between one ring magnet and the moving magnet has a stable equilibrium and a minimal point. This enables the proposed magnetic spring to have significant nonlinearity in a short stroke, with a variety of tunability of the restoring force with different linear stiffness, even including essential nonlinearity and bistability, by changing the distance between the ring magnets.
