ROTATING MACHINE WITH MAGNETIC BEARING

• US 20140259636A1
• Filed: 03/15/2014
• Published: 09/18/2014
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Ingersoll-Rand Industrial U.S., Inc. (Ingersoll Rand, Inc.)
• Original Assignee: Ingersoll-Rand Company (Trane Technologies plc)
• Inventors: Maki-Ontto, Petri Juhani, Salmia, Lauri Juhani
• Granted Patent: US 9,621,013 B2
• Time in Patent Office: Days
• US Class Current: 29/598
• CPC Class Codes: F16C 2380/26 Dynamo-electric machines or combinations therewith, e.g. electro-motors and generators in general H02K
• CPC Class Codes: F16C 32/0461 of stationary parts of the magnetic circuit
• CPC Class Codes: F16C 32/0476 with active support of one degree of freedom, e.g. axial magnetic bearings
• CPC Class Codes: F16C 32/048 with active support of two degrees of freedom, e.g. radial magnetic bearings
• CPC Class Codes: H02K 15/02 of stator or rotor bodies
• CPC Class Codes: H02K 2213/03 Machines characterised by numerical values, ranges, mathematical expressions or similar information
• CPC Class Codes: H02K 7/09 with magnetic bearings
• CPC Class Codes: Y10T 29/49012 Rotor

Abstract

A method of manufacturing an electrical machine includes selecting a desired threshold control current, selecting dimensions to modify stator teeth of a magnetic bearing based on the desired threshold control current, and modifying the stator teeth using the selected dimensions. A method of producing a rotating machine includes selecting an operating point of a magnetic bearing of the rotating machine, and shaping at least some stator teeth of the magnetic bearing to generate increased force at control currents above the control current at the selected operating point.

Claims

1. A method of manufacturing an electrical machine, comprising:

forming a rotor for a magnetic bearing of the electrical machine;

forming a stator for the magnetic bearing, wherein the stator has a plurality of stator teeth separated from the rotor by an air gap;

selecting a desired threshold control current, wherein the threshold control current defines a stator winding current value above which modified stator teeth generate a greater force on the rotor than do unmodified stator teeth;

selecting a first chamfer dimension based on the desired threshold control current;

selecting a second chamfer dimension based on the desired threshold control current;

selecting at least some of the stator teeth for modification; and

forming the selected stator teeth as modified stator teeth by incorporating a chamfer on the selected stator teeth using the selected first chamfer dimension and the selected second chamfer dimension.

2. The method of claim 1, wherein the first chamfer dimension is a height of the chamfer, and wherein the second chamfer dimension is a width of the chamfer.

3. The method of claim 1, further comprising selecting a desired operating condition, wherein the desired threshold control current is selected based on the desired operating condition of the magnetic bearing.

4. The method of claim 1, wherein all of the stator teeth are modified stator teeth.

5. The method of claim 1, wherein only some of the stator teeth are modified stator teeth.

6. The method of claim 5, wherein only the stator teeth that support the rotor gravity load are modified stator teeth.

7. The method of claim 1, wherein all of the modified stator teeth are formed with the same first chamfer dimension;

and wherein all of the modified stator teeth are formed with the same second chamfer dimension.

8. The method of claim 1, further comprising selecting the first chamfer dimension and the second chamfer dimension from a group of first chamfer dimensions and second chamfer dimensions that also yield the same threshold control current.

9. The method of claim 1, wherein the magnetic bearing is a hetero-polar and/or homo-polar magnetic bearing.

10. A method of producing a rotating machine, comprising:

forming a rotor for a magnetic bearing of the rotating machine;

forming a stator for the magnetic bearing, wherein the stator has a plurality of stator teeth separated from the rotor by an air gap;

selecting an operating point; and

shaping at least some of the stator teeth to generate increased force at control currents greater than a control current at the operating point, wherein the shaped stator teeth generate decreased force at control currents below the control current at the operating point.

11. The method of claim 10, wherein the all of the stator teeth are shaped stator teeth.

12. The method of claim 10, wherein only some of the stator teeth are shaped stator teeth.

13. The method of claim 12, wherein at least the stator teeth that support the rotor gravity load are shaped stator teeth.

14. The method of claim 10, wherein the shaping of the stator teeth includes forming a chamfer on the stator teeth.

15. The method of claim 14, wherein the control current at the operating point is a desired threshold control current;

and wherein the desired threshold control current defines a stator winding current value above which stator teeth having a selected chamfer form generate a greater force on the rotor than do stator teeth without chamfers.

16. The method of claim 15, further comprising:

selecting a first chamfer dimension based on the desired threshold control current; and

selecting a second chamfer dimension based on the desired threshold control current.

17. The method of claim 10, further comprising selecting a bearing controller having a lower current capacity than would be sufficient for normal bearing operation if the at least some of the stator teeth were not shaped stator teeth.

18. The method of claim 10, further comprising reducing a physical size of the magnetic bearing to achieve the same force in the reduced-size bearing as a bearing of greater physical size but not shaped stator teeth.

19. A method of producing a rotating machine, comprising:

forming a rotor for a magnetic bearing of the rotating machine;

forming a stator for the magnetic bearing, wherein the stator has a plurality of stator teeth; and

wherein the stator teeth are separated from the rotor by an air gap; and

a step for modifying the stator teeth.

20. The method of claim 19, wherein the step for modifying is based on selecting a desired threshold control current.