ROTOR OF BRUSHLESS MOTOR

• US 20080315691A1
• Filed: 08/14/2008
• Published: 12/25/2008
• Est. Priority Date: 05/11/2007
• Status: Active Grant

• Current Assignee: Bluffton Motor Works LLC (Wpa Participações e Serviços SA)
• Original Assignee: SNTech Incorporated
• Inventors: Jeung, Young-Chun
• Granted Patent: US 8,299,661 B2
• Time in Patent Office: Days
• US Class Current: 310/51
• CPC Class Codes: H02K 1/2733 Annular magnets

Abstract

Some embodiments of the present disclosure provide a rotor of an electric brushless motor configured to be light weight and prevent vibrations generated during an operation of the motor to be transferred to the shaft of the rotor. The rotor includes a shaft elongated in a rotational axis, a single body magnet comprising alternately magnetized portions, and a vibration absorption portion interposed between the shaft and single body magnet. The vibration absorption portion absorbs vibrations generated during the operation of the motor and can include an elastic or a non-elastic material. The rotor further includes a non-elastic portion inhibiting the expansion of the vibration absorption portion when the vibration portion is elastic.

Claims

1. A rotor of a brushless motor, comprising:

a shaft elongated in a rotational axis;

at least one body magnets comprising alternately magnetized portions; and

a vibration absorption portion interposed between the shaft and single body magnet.

2. The rotor of claim 1, wherein the one or more body magnets comprises a ring magnet surrounding at least a portion of the shaft.

3. The rotor of claim 2, wherein the ring magnet comprises two or more annular magnet portions arranged along the axis.

4. The rotor of claim 2, wherein the ring magnet comprises a plurality of poles extending generally parallel to each other.

5. The rotor of claim 1, wherein the one or more body magnets comprises a C shaped cross-section taken in a plane perpendicular to the axis.

6. The rotor of claim 1, wherein the one or more body magnets comprises a toroid shaped magnet surrounding at least a portion of the shaft.

7. The rotor of claim 1, wherein the one or more body magnets form a partial loop surrounding the shaft, wherein the rotor further comprises one or more additional body magnets, each additional single body permanent magnet comprising alternately magnetized portions.

8. The rotor of claim 7, wherein the one or more body magnets are arranged along the axis.

9. The rotor of claim 1, wherein the vibration absorption portion comprises an annular body and is surrounding the shaft.

10. The rotor of claim 9, wherein the vibration absorption portion is engaged with the shaft.

11. The rotor of claim 9, further comprising an engagement enhancing layer fixed to a circumference of the shaft, wherein the vibration absorption portion is engaged with the shaft via the engagement enhancing layer.

12. The rotor of claim 1, wherein the vibration absorption portion comprises an elastic material.

13. The rotor of claim 12, further comprising a non-elastic portion interposed between the single body magnet and the vibration absorption portion, wherein the non-elastic portion does not comprise an elastic material.

14. The rotor of claim 13, wherein the non-elastic portion is annular and surrounding the vibration absorption portion.

15. The rotor of claim 13, wherein the non-elastic portion is not annular while being interposed between the single body magnet and the vibration absorption portion.

16. The rotor of claim 13, wherein the non-elastic portion comprises a ferromagnetic material.

17. The rotor of claim 13, wherein the non-elastic portion does not comprise a ferromagnetic material.

18. The rotor of claim 12, further comprising a non-elastic portion interposed between the single body magnet and the vibration absorption portion, wherein the non-elastic portion is substantially non-elastic and configured to minimize transferring of a force of radial expansion of the vibration absorption portion to the single body magnet while the rotor is rotating.

19. The rotor of claim 18, wherein the non-elastic portion is engaged with the single body magnet.

20. The rotor of claim 19, wherein the non-elastic portion comprises at least one of protrusion and recess on an outer circumference, wherein the single body magnet comprises at least one counterpart configuration configured to engage with the at least one of protrusion and recess.

21. The rotor of claim 12, further comprising a non-elastic portion interposed between the single body magnet and the vibration absorption portion, wherein the non-elastic portion comprises one or more annular layers.

22. The rotor of claim 21, wherein the non-elastic portion is engaged with the vibration absorption portion.

23. The rotor of claim 22, wherein the non-elastic portion comprises at least one of protrusion and recess on an inner circumference, wherein the vibration absorption portion comprises at least one counterpart configuration configured to engage with the at least one of protrusion and recess.

24. The rotor of claim 1, wherein the vibration absorption portion is not annular while being interposed between the shaft and the one or more body magnets.

25. The rotor of claim 1, wherein the vibration absorption portion is substantially free of an elastic material.

26. The rotor of claim 1, wherein the vibration absorption portion comprises a pored structure.

27. The rotor of claim 26, wherein the pored structure comprises a plurality of networked walls defining pores.

28. A brushless motor comprising:

the rotor of claim 1; and

a stator comprising at least two electric magnets.