5. Applications

The stiffness of passive magnetic bearings is generally much lower than that of active bearings. It is generally of the order of a few tens of newtons per millimeter. Their axial or radial load is also lower. As a result, passive bearings are poorly suited to systems subject to high loads (e.g. grinding machine spindles). On the other hand, as passive bearings are very simple magnetomechanical systems, they are much easier to use than active bearings.

The main field of application for passive bearings will therefore be applications where the rotor is subject to only minor disturbances. The use of passive bearings makes magnetic suspensions simpler, more robust and less expensive than all-active systems.

These passive bearings are mainly used in systems running at very high speeds:

• satellite...