Magnetic bearing

A magnetic bearing (20) comprising:

• a rotor (22) to be supported for rotation about an axis (502);
• a stator (24) extending from a first end (30) to a second end (32) and comprising:
• one or more first permanent magnets (110);
• one or more second permanent magnets (112) of polarity substantially opposite to a polarity of the one or more first permanent magnets;
• at least three radial windings (40,42,44,46);
• a first axial winding (34);
• a second axial winding (36);
• a first end pole (120);
• and
• a second end pole (122),
• wherein in central longitudinal half-section centrally through one of the at least three radial windings:
• a first radial flux loop (540, 542, 544, 546) or reverse thereof:
• passes radially outward through a central laminate of the stator passing within said one of the at least three radial windings;
• turns axially outboard in a central back iron;
• passes axially outboard through the one or more first permanent magnets;
• turns radially inward within a first end back iron;
• passes radially inward through a first end laminate stack;
• jumps a radial gap to pass radially through a rotor laminate stack;
• turns axially inward axially inboard of the rotor laminate stack;
• turns radially outward to pass back through the rotor laminate stack;
• and
• jumps the radial gap to complete the first radial flux loop;
• a first axial flux loop (550, 552, 554, 556) or reverse thereof:
• passes radially through the first end laminate stack;
• turns axially outboard through the first end back iron;
• passes axially outward, turns and passes radially inward, and then turns and passes axially inward within the first end pole;
• jumps the axial gap between the first end pole and the rotor axially inboard of the rotor laminate stack;
• turns radially outward to pass back radially outward through the rotor laminate stack;
• and
• jumps the radial gap to complete the first axial loop;
• and
• a first PM bias axial flux loop (530, 532, 534, 536) or reverse thereof:
• passes radially outward through the central laminate of the stator passing within the first of the diametrically opposite windings;
• turns axially outboard in the central back iron;
• passes axially outboard through the one or more first permanent magnets;
• passes axially outboard through the first end back iron;
• turns radially inward and then axially inward within the first end pole;
• jumps an axial gap between the first end pole and the rotor axially inboard of the rotor laminate stack;
• turns radially outward to pass back through the rotor laminate stack;
• and
• jumps the radial gap to complete the first PM bias axial flux loop.

A magnetic bearing (20) comprising:

• a rotor (22) to be supported for rotation about an axis (502) and having a rotor laminate stack (150);
• a stator (24) extending from a first end (30) to a second end (32) and comprising:
• one or more first permanent magnets (110);
• one or more second permanent magnets (112) of polarity substantially opposite to a polarity of the one or more first permanent magnets;
• at least three radial windings (40,42,44,46);
• a first axial winding (34);
• a second axial winding (36);
• a first end pole (120);
• a second end pole (122);
• a first axial gap (200) between the first end pole and a first end (162) of rotor material (160) radially inboard of an inner diameter surface of the rotor laminate stack (150);
• and
• a second axial gap (202) axially opposite the first axial gap between the second end pole and a second end (164) of the rotor material.

A magnetic bearing (20) comprising:

• a rotor (22) to be supported for rotation about an axis (502) and having a rotor laminate stack (150);
• a stator (24) extending from a first end (30) to a second end (32) and comprising:
• one or more first permanent magnets (110);
• one or more second permanent magnets (112) of polarity substantially opposite to a polarity of the one or more first permanent magnets;
• at least three radial windings (40,42,44,46);
• a first axial winding (34);
• a second axial winding (36);
• a first end pole (120);
• a second end pole (122);
• one or more first end laminate stacks (130) and one or more first end back irons (132) between the first permanent magnet and first end pole;
• one or more second end laminate stacks (140) and one or more second end back irons (142) between the second permanent magnet and second end pole;
• a center laminate (50, 52, 54, 56);
• and
• a radial gap between the rotor laminate stack (150) and the center laminate, one or more first end laminate stacks, and one or more second end laminate stacks.