Radial and torsionally controlled magnetic bearing

An active magnetic bearing system for producing both radial and torsional forces comprising:

• an inner generally circular stator member having a plurality of peripheral outer surfaces defining a set of curvilinear exterior pole faces;
• an outer annular magnetic permeable ring assembly coaxial with said stator member about a longitudinal axis, said ring assembly having a like plurality of inwardly projecting rims separated by rings of permanent magnets which are mutually magnetically opposed to one another, said rims having surfaces defining a set of curvilinear interior pole faces disposed opposite said set of exterior pole faces and being separated therefrom by respective circumferential air gaps;
• said stator member being further comprised of a central magnetically permeable disc member having a pair of opposing faces lying in a plane perpendicular to said longitudinal axis, a pair of disc type permanent magnets located on said opposing faces and being oriented so that their magnetic polarities are mutually opposed, a first and second set of magnetically permeable disc segments respectively located on the outer surface of said permanent magnets and including means for magnetically coupling diametrically opposite segments to direct flux across said air gaps along first and second mutually orthogonal radial axes perpendicular to said longitudinal axes, said permanent magnets providing a substantially uniform radial DC flux across said circumferential air gaps which by itself provides axial stabilization of said ring member about said stator member, and coil winding means located on said disc segments and being selectively energizable to produce a first control flux which combines with said DC flux to radially stabilize said ring about said longitudinal axis and a second control flux which combines with said DC flux for producing differential forces across said circumferential air gaps to generate a torque of said ring member about said first and second orthogonal axes.

An active magnetic bearing, comprising:

• an inner generally circular stator member having two peripheral outer surfaces defining curvilinear exterior pole faces;
• an outer annular magnetically permeable ring member coaxial with said stator member about a longitudinal axis and having two inwardly projecting rims having surfaces defining a set of curvilinear interior pole faces disposed opposite said exterior pole faces of the stator member and being separated therefrom by a first and second circumferential air gap;
• said stator member being further comprised of a central permanent magnet member providing a DC flux across said first and second air gaps and having a pair of opposing faces lying in a plane perpendicular to said longitudinal axis, a first and second set of segmented magnetically permeable disc members respectively located on said pair of opposing faces and including means for being magnetically coupled to direct flux across said first and second air gaps along first and second mutually orthogonal radial axes perpendicular to said longitudinal axis and coil winding means located on said stator member and being selectively energized to produce a first control flux for producing radial stabilizing forces of said ring member about said longitudinal axis when summed with said DC flux and to produce a second control flux to generate a torque of said ring member about said first and second orthogonal axis in a predetermined direction when summed with said DC flux.