PERMANENT MAGNET MACHINE

• US 20150380999A1
• Filed: 06/27/2014
• Published: 12/31/2015
• Est. Priority Date: 06/27/2014
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Joshi, Narendra Digamber, Shah, Manoj Ramprasad, Bray, James William, Vondrell, Randy Marinus, Murrow, Kurt David, Hamel, Jeffrey Anthony, Martin, Samuel Jacob
• Granted Patent: US 10,381,889 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H02K 1/182 to stators axially facing the rotor, i.e. with axial or conical air gap
• CPC Class Codes: H02K 1/278 Surface mounted magnets; Inset magnets
• CPC Class Codes: H02K 1/28 Means for mounting or fastening rotating magnetic parts on to, or to, the rotor structures
• CPC Class Codes: H02K 1/30 using intermediate parts, e.g. spiders
• CPC Class Codes: H02K 21/026 Axial air gap machines
• CPC Class Codes: H02K 21/24 with magnets axially facing the armatures, e.g. hub-type cycle dynamos
• CPC Class Codes: H02K 49/108 with an axial air gap
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction

Abstract

A permanent magnet machine and a rotor assembly for the permanent magnet machine. The permanent magnet machine includes a stator assembly including a stator core configured to generate a magnetic field and extending along a longitudinal axis with an inner surface defining a cavity and a rotor assembly including a rotor core and a rotor shaft. The rotor core is disposed inside the stator cavity and configured to rotate about the longitudinal axis. The rotor assembly further including a plurality of permanent magnets for generating a magnetic field which interacts with the stator magnetic field to produce torque. The permanent magnets are disposed within one or more cavities formed in a sleeve component. The sleeve component configured to include a plurality of cavities or voids therein and thus provide minimal weight to the permanent magnet machine. The permanent magnet machine providing increased centrifugal load capacity, increased power density and improved electrical performance.

Claims

1. A rotor assembly for a permanent magnet machine configured to rotate about a longitudinal axis, the rotor assembly comprising:

a rotor shaft; and

at least one rotor module configured to generate a magnetic field, whose magnetic field interacts with a stator magnetic field to produce a torque, the at least one rotor module disposed about the rotor shaft, the at least one rotor module comprising;

a plurality of permanent magnets; and

a sleeve component including a plurality of cavities formed therein, wherein at least one of the plurality of permanent magnets is disposed within one of the plurality of cavities formed in the sleeve component to retain the at least one permanent magnet therein and form an interior permanent magnet motor.

2. The rotor assembly as claimed in claim 1, further comprising a plurality of rotor modules configured in an end-to-end axial alignment and cooperative engagement.

3. The rotor assembly as claimed in claim 1, wherein the sleeve component is configured as a segmented component including a plurality of individual sleeve segments and wherein adjacent sleeve segments are cooperatively adjoined.

4. The rotor assembly as claimed in claim 1, wherein the sleeve component is configured to include one or more land portions and one or more disc portions defining the plurality of cavities.

5. The rotor assembly as claimed in claim 1, wherein the sleeve component further comprises one or more internal rib structures further defining the plurality of cavities and providing centrifugal stiffening.

6. The rotor assembly as claimed in claim 1, wherein a magnetization direction of each of the plurality of permanent magnets is configured relative to the longitudinal axis of the rotor assembly as one of radially inward, radially outward or circumferential.

7. The rotor assembly as claimed in claim 1, wherein each of the plurality of permanent magnets is separated from another one of the plurality of permanent magnets by a non-magnetic material.

8. A rotor assembly for a permanent magnet machine configured to rotate about a longitudinal axis, the rotor assembly comprising:

a rotor shaft; and

a plurality of rotor modules configured to generate a magnetic field, whose magnetic field interacts with a stator magnetic field to produce a torque, the plurality of rotor modules disposed about the rotor shaft in an end-to-end axial alignment and cooperative engagement, each of the plurality of rotor modules defining a rotor core comprising;

a plurality of permanent magnets; and

a sleeve component including a plurality of cavities formed therein, wherein at least one of the plurality of permanent magnets is disposed within one of the plurality of cavities formed in the sleeve component to retain the at least one permanent magnet therein and form an interior permanent magnet motor.

9. The rotor assembly as claimed in claim 8, wherein the sleeve component is configured as a segmented component including a plurality of individual sleeve segments

10. The rotor assembly as claimed in claim 8, wherein the sleeve component is configured to include one of a plurality of land portions and disc portions defining the plurality of cavities or one or more internal rib structures further defining the plurality of cavities, the plurality of land portions and disc portions or the one or more internal rib structures providing centrifugal stiffening to the sleeve component.

11. The rotor assembly as claimed in claim 8, wherein each of the plurality of permanent magnets is separated from another one of the plurality of permanent magnets by a non-magnetic material.

12. The rotor assembly as claimed in claim 8, wherein a magnetization direction of each of the plurality of permanent magnets is configured relative to the rotor assembly longitudinal axis as one of radially inward, radially outward or circumferential.

13. A permanent magnet machine comprising:

a stator assembly comprising a stator core and including stator windings to generate a stator magnetic field when excited with alternating currents, the stator assembly extending along a longitudinal axis with an inner surface defining a cavity; and

a rotor assembly disposed inside said cavity and configured to rotate about the longitudinal axis, wherein the rotor assembly comprises at least one rotor module configured to generate a magnetic field, which magnetic field interacts with a stator magnetic field to produce a torque, the at least one rotor module comprising;

a plurality of permanent magnets; and

a sleeve component including a plurality of cavities formed therein,

wherein at least one of the plurality of permanent magnets is disposed within one of the plurality of cavities formed in the sleeve component to retain the at least one permanent magnet and form an interior permanent magnet motor, wherein an air gap is defined between the rotor assembly and the stator assembly.

14. The permanent magnet machine as claimed in claim 13, wherein the sleeve component is configured as a segmented component including a plurality of individual sleeve segments and wherein adjacent sleeve segments are cooperatively adjoined.

15. The permanent magnet machine as claimed in claim 13, wherein the sleeve component is configured to include one or more land portions and one or more disc portions defining the plurality of cavities.

16. The permanent magnet machine as claimed in claim 13, wherein the sleeve component further comprises one or more internal rib structures further defining the plurality of cavities and providing centrifugal stiffening.

17. The permanent magnet machine as claimed in claim 13, wherein each of the plurality of permanent magnets is separated from another one of the plurality of permanent magnets by a non-magnetic material.

18. The permanent magnet machine as claimed in claim 13, wherein the permanent magnet machine is an axial flux machine.

19. The permanent magnet machine as claimed in claim 13, wherein the permanent magnet machine is a radial flux machine.

20. The permanent magnet machine as claimed in claim 13, wherein the permanent magnet machine is a permanent magnet motor for driving at least one of an aircraft engine, a pump, a wind turbine, a gas turbine, or a generator.