Claims
- 1. An electric motor, comprising:
- a base;
- a rotor housing rotatably mounted to said base for rotation about an axis, said rotor housing having a substantially cylindrical first hub portion having a first diameter, and a substantially cylindrical second hub portion having a second diameter, said second diameter being greater than said first diameter, said first and second hub portions being cylindrical about said axis;
- a first set of permanent magnets mounted within said first hub portion of said rotor housing and surrounding said axis at a first radial distance;
- a second set of permanent magnets mounted within said second hub portion of said rotor housing and surrounding said axis at a second radial distance, said second radial distance being greater than said first radial distance;
- an electromagnetic stator assembly rigidly mounted to said base and surrounding said axis, said stator including a first stator portion for driving said first set of permanent magnets, and a second stator portion for driving said second set of permanent magnets.
- 2. The electric motor of claim 1, wherein said first set of permanent magnets is circumferentially offset from said second set of permanent magnets.
- 3. The electric motor of claim 1, wherein said electromagnetic stator assembly comprises a plurality of cores surrounding said axis, and at least one winding surrounding each respective core, each core having a substantially L-shaped cross-section in a plane containing said axis, forming two legs of said core, a first leg of said core being adjacent said first set of permanent magnets, and a second leg of said core being adjacent said second set of permanent magnets, said first stator portion comprising the first leg of each respective core, and said second stator portion comprising the second leg of each respective core.
- 4. The electric motor of claim 1, wherein said electromagnetic stator assembly comprises a first set of cores and a second set of cores, each set of cores comprising a plurality of cores surrounding said axis, said stator assembly further comprising at least one winding surrounding each respective core, said first set of cores being positioned adjacent said first set of permanent magnets and said second set of cores being positioned adjacent said second set of permanent magnets, said first stator portion comprising said first set of cores, and said second stator portion comprising said second set of cores.
- 5. The electric motor of claim 4, wherein said first set of cores is circumferentially offset from said second set of cores.
- 6. The electric motor of claim 4, wherein said first set of permanent magnets is circumferentially offset from said second set of permanent magnets.
- 7. The electric motor of claim 4, wherein said first and second set of cores are selectively powered.
- 8. The electric motor of claim 1, further comprising a non-magnetic annular member mounted within said rotor housing and to which said first and second sets of permanent magnets are attached, said first set of permanent magnet being attached to a first surface of said annular member near its inner edge, and said second set of permanent magnets being attached to a second surface of said annular member near its outer edge, said annular member fixing the relative circumferential positions of said first and second sets of permanent magnets.
- 9. The electric motor of claim 1, wherein said rotor housing further comprises a supporting structure for providing mechanical support to a rotating member attached to said rotor housing.
Parent Case Info
This is a continuation of co-pending application Ser. No. 08/286,760 filed on Aug. 5, 1994.
US Referenced Citations (10)
Foreign Referenced Citations (1)
Number |
Date |
Country |
2743564 |
Mar 1979 |
DEX |
Divisions (1)
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Number |
Date |
Country |
Parent |
286760 |
Aug 1994 |
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