WO1997003301B1 - Magnetic bearing with reduced bias-flux-induced rotor loss - Google Patents
Magnetic bearing with reduced bias-flux-induced rotor lossInfo
- Publication number
- WO1997003301B1 WO1997003301B1 PCT/US1996/010694 US9610694W WO9703301B1 WO 1997003301 B1 WO1997003301 B1 WO 1997003301B1 US 9610694 W US9610694 W US 9610694W WO 9703301 B1 WO9703301 B1 WO 9703301B1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- stator
- rotor
- bearing
- gap
- bridge
- Prior art date
Links
- 230000004907 flux Effects 0.000 claims abstract 11
- 230000035699 permeability Effects 0.000 claims 2
- 230000017525 heat dissipation Effects 0.000 abstract 1
Abstract
A magnetic bearing with reduced bias-flux-induced rotor loss includes a stator (12), a rotor (14), the stator (12) having a configuration which minimizes a gap (g1) between stator teeth (80) thereby providing a more nearly uniform spatial distribution of the bias flux around the rotor-stator gap. The reduction in rotor losses include reduction in eddy current and hysteresis losses, thereby reducing electromagnetic drag and heat dissipation in the rotor associated with such losses, especially in high speed rotor applications.
Claims
97/03301 AMENDED CLAIMS PCT/US96/10694
[received by the International Bureau on 21 January 1997 (21.01.97); original claims 1 and 7 amended; new claims 12-19 added; remaining claims unchanged (3 pages)] 1. A magnetic bearing, comprising: a stator having a plurality of stator teeth; a rotor, concentrically located with respect to said stator, which rotates relative to said stator, there being a rotor/stator gap between said rotor and said stator; said rotor and said stator being oriented to allow a magnetic bias flux to flow between said stator and said rotor across said rotor/stator gap; and there being a tooth gap between adjacent ones of said stator teeth near said rotor/stator gap, said tooth gap being set to a minimum distance to minimize losses in said rotor caused by said bias flux.
2. The bearing of claim 1 wherein said stator teeth have a monotonically radially increasing width.
3. The bearing of claim 1 wherein the number of said plurality of stator teeth comprises: 8, 12, or 16 stator teeth.
4. The bearing of claim 1 wherein said minimum distance creates a substantially uniform spatial distribution of said bias flux around said rotor/stator gap.
5. The bearing of claim 1 wherein said bias flux is generated by a permanent magnet.
-20-
6. A magnetic bearing, comprising: stator means; rotor means, concentrically located with respect to said stator means, which rotates relative to said stator means, there being a rotor/stator gap between said rotor means and said stator means stator, bias flux means for generating a magnetic bias flux between said rotor means and said stator means across said rotor/stator gap; and said stator means for minimizing losses in said rotor caused by said bias flux.
7. The bearing of claim 6 wherein said stator means comprises a plurality of stator teeth disposed on said stator means and there being a tooth gap between adjacent ones of said stator teeth near said rotor/stator gap, said tooth gap being set to a minimum distance to minimize losses in said rotor caused by said bias flux.
8. The bearing of claim 7 wherein said stator teeth have a monotonically radially increasing width.
9. The bearing of claim 7 wherein the number of said plurality of stator teeth comprises: 8, 12, or 16 stator teeth.
10. The bearing of claim 7 wherein said minimum distance creates a substantially uniform spatial distribution of said bias flux around said rotor/stator gap.
11. The bearing of claim 6 wherein said bias flux means comprises a permanent magnet.
12. The bearing of claim 1 further comprising a bridge disposed across said tooth gap which closes said tooth gap near said rotor/stator gap.
13. The bearing of claim 12 wherein said bridge comprises a material having low magnetic permeability.
14. The bearing of claim 12 wherein said bridge comprises the same material as that of said stator.
15. The bearing of claim 12 wherein said bridge comprises a notch in an outer surface of said bridge.
16. The bearing of claim 6 further comprising bridge means disposed across said tooth gap for closing said tooth gap near said rotor/stator gap.
17. The bearing of claim 16 wherein said bridge means comprises a material having low magnetic permeability.
18. The bearing of claim 16 wherein said bridge means comprises the same material as that of said stator.
19. The bearing of claim 16 wherein said bridge means comprises a notch in an outer surface of said bridge means.
-22-
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US50072195A | 1995-07-11 | 1995-07-11 | |
| US08/500,721 | 1995-07-11 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| WO1997003301A1 WO1997003301A1 (en) | 1997-01-30 |
| WO1997003301B1 true WO1997003301B1 (en) | 1997-02-20 |
Family
ID=23990636
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/US1996/010694 WO1997003301A1 (en) | 1995-07-11 | 1996-06-21 | Magnetic bearing with reduced bias-flux-induced rotor loss |
Country Status (2)
| Country | Link |
|---|---|
| TW (1) | TW305083B (en) |
| WO (1) | WO1997003301A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2759749B1 (en) * | 1997-02-14 | 1999-05-14 | Aerospatiale | PASSIVE MODEL DAMPING MAGNETIC BEARING |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3079574A (en) * | 1960-01-06 | 1963-02-26 | Research Corp | Combined magnetic suspension and rotary transformer |
| US3224818A (en) * | 1962-12-10 | 1965-12-21 | Sixsmith Herbert | Combined electromagnetic and electromechanical power converter |
| JPS61180019A (en) * | 1985-01-28 | 1986-08-12 | Yaskawa Electric Mfg Co Ltd | magnetic bearing |
-
1996
- 1996-06-21 WO PCT/US1996/010694 patent/WO1997003301A1/en active Application Filing
- 1996-06-26 TW TW85107699A patent/TW305083B/zh active
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