Bearing arrangement

A device comprising:

• a first member;
• a second member disposed for rotation within, and about an axis relative to, the first member;
• means defining an electric motor and rotating said second member and including a motor stator on said first member;
• a first magnetic bearing unit composed of at least one permanent magnet mounted on one of said members and a component part of the other of said members composed at least in part of ferromagnetic material and cooperating with said permanent magnet;
• a second magnetic bearing unit composed of at least one actively controlled electromagnet mounted on said first member and a component part of said second member composed at least in part of ferromagnetic material and cooperating with said electromagnet;
• said first and second magnetic bearing units providing axial tensioning forces for said second member and having a substantially coaxial configuration to effect passive stabilization in the radial direction;
• a sensor disposed for sensing the axial position of said second member relative to said first member and connected to control the axial force produced by said second magnetic bearing unit;
• damping circuit means disposed for damping oscillations of said second member in a radial direction and including a coil mounted on said first member;
• wherein said second member comprises a bell-shaped portion, and said second magnetic bearing unit, said sensor, said coil of said damping circuit means and said motor stator constitute a group of components extending at least partially into said bell-shaped portion.