Permanent magnet rotors for electric motors, particularly electric motors for use in compressors, improve the electromagnetic efficiency of the motor. The rotors can include retention of surface permanent magnets using one or more of retaining features on the motor and/or pole spacers interfacing with corresponding features on a rotor core, the use of a monolithic magnet in the rotor, and/or use of a carbon fiber sleeve. The rotor can include an eddy current shield, disposed on the rotor core, on a surface of the rotor, or located within a sleeve surrounding the rotor. The rotor can be sized such that an air-gap between the rotor and a stator of a motor using the rotor is a predetermined amount that reduces electromagnetic losses such as eddy current losses.

A rotor assembly (10) has a rotor support hub (12) which includes a plurality of first connection parts arranged about a periphery the rotor support hub. The rotor assembly further has a plurality of rotor segments (14) each having a second connection part. Each of the second connection parts are cooperable with at least one of the plurality of first connection parts to connect each of the rotor segments about the periphery the rotor support hub. A plurality of fixing parts (26) are each configured to be received between cooperating first and second connection parts and to form an inference fit therebetween so as to secure the rotor segments to the rotor support hub. The rotor support hub may comprise a plurality of laminations.

A rotor assembly (10) has a rotor support hub (12) which includes a plurality of first connection parts arranged about a periphery the rotor support hub. The rotor assembly further has a plurality of rotor segments (14) each having a second connection part. Each of the second connection parts are cooperable with at least one of the plurality of first connection parts to connect each of the rotor segments about the periphery the rotor support hub. A plurality of fixing parts (26) are each configured to be received between cooperating first and second connection parts and to form an inference fit therebetween so as to secure the rotor segments to the rotor support hub. The rotor support hub may comprise a plurality of laminations.

Disclosed is a motor rotor structure including a rotor core. A plurality of radial slots each are in the rotor core along a circumferential direction, and a first flux barrier slot is provided between every two adjacent radial slots. Two kinds of permanent magnets having different coercivities mounted in each radial slot. The two kinds of permanent magnets having different coercivities are distributed along a radial direction of the rotor core. The two kinds of permanent magnets having different coercivities are both magnetized along a tangential direction of the rotor core. A second flux barrier slot is provided between the two kinds of permanent magnets having different coercivities.

Disclosed is a motor rotor structure including a rotor core. A plurality of radial slots each are in the rotor core along a circumferential direction, and a first flux barrier slot is provided between every two adjacent radial slots. Two kinds of permanent magnets having different coercivities mounted in each radial slot. The two kinds of permanent magnets having different coercivities are distributed along a radial direction of the rotor core. The two kinds of permanent magnets having different coercivities are both magnetized along a tangential direction of the rotor core. A second flux barrier slot is provided between the two kinds of permanent magnets having different coercivities.

Permanent magnet rotors for electric motors, particularly electric motors for use in compressors, improve the electromagnetic efficiency of the motor. The rotors can include retention of surface permanent magnets using one or more of retaining features on the motor and/or pole spacers interfacing with corresponding features on a rotor core, the use of a monolithic magnet in the rotor, and/or use of a carbon fiber sleeve. The rotor can include an eddy current shield, disposed on the rotor core, on a surface of the rotor, or located within a sleeve surrounding the rotor. The rotor can be sized such that an air-gap between the rotor and a stator of a motor using the rotor is a predetermined amount that reduces electromagnetic losses such as eddy current losses.

A permanent magnet energy converter is described wherein the converter comprises: a stator structure including a stator magnet having a spiral geometry; the stator magnet having a U-shaped cross-section, a first leg of the U-shaped cross-section forming a first magnetic pole and a second leg of the U-shaped cross-section forming a second magnetic pole; an elongated rotor structure having a first and second end being positioned within the stator structure, the rotor structure being configured to rotate about rotation axis, herein the rotor structure includes: first and second elongated core elements of a magnetizable material, a first end and second end of the first core element being aligned with the first magnetic pole of the stator magnet and a first end and second end of the second core element being aligned with second magnetic pole of the stator magnet; one or more permanent magnets arranged to magnetize the first and second elongated core elements; and, a first magnetic coil structure for reversing the magnetic polarity of the first end of

A permanent magnet energy converter is described wherein the converter comprises: a stator structure including a stator magnet having a spiral geometry; the stator magnet having a U-shaped cross-section, a first leg of the U-shaped cross-section forming a first magnetic pole and a second leg of the U-shaped cross-section forming a second magnetic pole; an elongated rotor structure having a first and second end being positioned within the stator structure, the rotor structure being configured to rotate about rotation axis, herein the rotor structure includes: first and second elongated core elements of a magnetizable material, a first end and second end of the first core element being aligned with the first magnetic pole of the stator magnet and a first end and second end of the second core element being aligned with second magnetic pole of the stator magnet; one or more permanent magnets arranged to magnetize the first and second elongated core elements; and, a first magnetic coil structure for reversing the magnetic polarity of the first end of

A rotor of a synchronous motor is provided with a plurality of magnets fixed to an outer circumferential surface of a rotor core, and a reinforcement member having a cylindrical shape. An interposition member is disposed between the magnet and the reinforcement member. The magnet includes an outer circumferential surface whose center portion in the circumferential direction bulges outward. The interposition member is formed so as to cover the entire outer circumferential surface of the magnet. An outer circumferential surface of the interposition member has a circular shape when cutting along a plane perpendicular to a rotation axis, and is in close contact with an inner circumferential surface of the reinforcement member.

An electric motor includes an armature and a mover. The armature includes an armature coil. The mover includes a plurality of pole blocks each including an iron core disposed to face the armature and a plurality of permanent magnets which surround the iron core such that a surface of the iron core, which faces the armature, is open. The plurality of permanent magnets in each pole block are disposed such that magnetic poles thereof facing the iron core are equal in polarity.