Power saving magnetic field control for magnetorheological fluid using permanent magnet

Generally, the magnetic field applied to the magnetorheological fluid (MRF) is generated by electromagnets. It has an issue that the electromagnets should consume the electric power during magnetizing MRF. In this research, for the purpose to power saving, we examined two kinds of magnetizing mechanism to control the magnetic field intensity on MRF, using permanent magnets instead of electromagnets. One mechanism moves a permanent magnet linearly into the yoke poles in the magnetic circuits of MRF magnetizing mechanism, and controls the magnetic field intensity on MRF by changing the overlap between the permanent magnet and yoke pole. The other mechanism rotates the permanent magnet with respect to the yoke, and controls the magnetic field intensity on MRF by changing relative angular position between the permanent magnet and yoke. Normally, these two mechanisms generate force or torque towards a magnetically stable position with respect to the permanent magnet, and the force or torque causes power consumption to hold and to move the permanent magnet.