Dynamics of a magnetic gear with two cogging-free operation modes

The coupling of two rotating spherical magnets is investigated experimentally. For two specific angles between the input and output rotation axes, a cogging-free coupling is observed, where the driven magnet is phase-locked to the driving one. The striking difference between these two modes of operation is the reversed sense of rotation of the driven magnet. For other angles, the experiments reveal a more complex dynamical behavior, which is divided in three different classes. This is done by analyzing the deviation from a periodic motion of the driven magnet, and by measuring the total harmonic distortion of this rotation. The experimental results can be understood by a mathematical model based on pure dipole-dipole interaction, with the addition of adequate friction terms.

Automated summary

The experimental study investigated the coupling of two rotating spherical magnets, finding a cogging-free coupling at specific angles where the driven magnet is phase-locked to the driving one with reversed rotation. For other angles, a more complex dynamical behavior was observed, divided into three different classes based on deviation from periodic motion and total harmonic distortion of the rotation of the driven magnet. The experimental results were explained by a mathematical model with dipole-dipole interaction and friction terms.