Motor having rotor formed by using thermosetting resin

• US 20020047329A1
• Filed: 05/11/2000
• Published: 04/25/2002
• Est. Priority Date: 05/13/1999
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Sashino, Masahiro, Sakano, Tomiaki, Matsubara, Masaaki
• Granted Patent: US 6,489,696 B2
• Time in Patent Office: Days
• US Class Current: 310/43
• CPC Class Codes: H02K 1/2733 Annular magnets
• CPC Class Codes: H02K 21/14 with magnets rotating within the armatures
• CPC Class Codes: H02K 5/06 Cast metal casings

Abstract

A rotor of a motor has a cylindrical magnet coaxially disposed with a shaft. The shaft and the magnet are bonded with thermosetting resin formed by injection molding. Since the molding shrinkage of the thermosetting resin is so small that a high preciseness is achieved in the motor structure. This precision structure can reduce vibration due to unbalance of a rotor. Also, an annealing process, in which a motor is left at a temperature higher than the limit temperature for operating the motor, can be eliminated. As a result, the efficiency of producing the motor can be improved.

Claims

1. A motor comprising:

(a) a rotor including;

a cylindrical magnet having a plurality of poles magnetized in a circumference direction; and

a shaft coaxially incorporated into said magnet with a molded member made of thermosetting resin,

(b) a stator facing to said rotor via an air space.

2. The motor as defined in claim 1, wherein a ratio of an axial height vs. an inner diameter of said magnet is not less than 0.3.

4. The motor as defined in claim 1, wherein the molded member is formed by insertion molding.

5. The motor as defined in claim 2, wherein the molded member is formed by insertion molding.

7. The motor as defined in claim 1, wherein the thermosetting resin includes unsaturated polyester resin whose weight density ratio is not less than 10% and not more than 30%.

8. The motor as defined in to claim 2, wherein the thermosetting resin includes unsaturated polyester resin whose weight density ratio is not less than 10% and not more than 30%.

10. The motor as defined in claim 1, wherein the thermosetting resin includes unsaturated polyester resin whose weight density ratio is not less than 10% and not more than 30%, and thermoplastic resin whose weight ratio with respect to the unsaturated polyester resin is not less than 10% and not more than 30%.

11. The motor as defined in claim 2, wherein the thermosetting resin includes unsaturated polyester resin whose weight density ratio is not less than 10% and not more than 30%, and thermoplastic resin whose weight ratio with respect to the unsaturated polyester resin is not less than 10% and not more than 30%.

13. The motor as defined in claim 1, wherein the thermosetting resin includes unsaturated polyester resin whose weight density ratio is not less than 10% and not more than 30%, and glass fiber whose weight density ratio is not less than 5% and not more than 15%.

14. The motor as defined in claim 2, wherein the thermosetting resin includes unsaturated polyester resin whose weight density ratio is not less than 10% and not more than 30%, and glass fiber whose weight density ratio is not less than 5% and not more than 15%.

16. The motor according to claim 1, wherein the thermosetting resin includes thermoplastic resin whose weight density ratio is not less than 10% and not more than 15%.

17. The motor as defined in claim 2, wherein the thermosetting resin includes thermoplastic resin whose weight density ratio is not less than 10% and not more than 15%.

3. A motor comprising:

(a) a rotor including;

two cylindrical magnets having a plurality of poles magnetized in a circumference direction and disposed coaxially with each other;

a spacer having a section contacting with inner walls of said two magnets and a section separating said two magnets;

a shaft incorporated with said magnets and said spacer coaxially with a molded member formed of thermosetting resin; and

(b) a stator facing to said rotor via an air space.

6. The motor as defined in claim 3, wherein the molded member is formed by insertion molding.

9. The motor as defined in claim 3, wherein the thermosetting resin includes unsaturated polyester resin whose weight density ratio is not less than 10% and not more than 30%.

12. The motor as defined in claim 3, wherein the thermosetting resin includes unsaturated polyester resin whose weight density ratio is not less than 10% and not more than 30%, and thermoplastic resin whose weight ratio with respect to the unsaturated polyester resin is not less than 10% and not more than 30%.

15. The motor as defined in claim 3, wherein the thermosetting resin includes unsaturated polyester resin whose weight density ratio is not less than 10% and not more than 30%, and glass fiber whose weight density ratio is not less than 5% and not more than 15%.

18. The motor as defined in claim 3, wherein the thermosetting resin includes thermoplastic resin whose weight density ratio is not less than 10% and not more than 15%.