STATOR CORE OF MOTOR, AND MANUFACTURING METHOD

• US 20130187514A1
• Filed: 09/27/2011
• Published: 07/25/2013
• Est. Priority Date: 10/08/2010
• Status: Active Grant

• Current Assignee: NHK Spring Company Limited
• Original Assignee: NHK Spring Company Limited
• Inventors: Iwata, Kazuo, Mino, Yoshinobu
• Granted Patent: US 9,276,441 B2
• Time in Patent Office: Days
• US Class Current: 310/216.009
• CPC Class Codes: H02K 1/16 Stator cores with slots for windings
• CPC Class Codes: H02K 1/185 to outer stators
• CPC Class Codes: H02K 15/024 with slots
• CPC Class Codes: H02K 2201/09 Magnetic cores comprising laminations characterised by being fastened by caulking

Abstract

A stator core comprises a circumferentially deformable part formed on a radially outer peripheral side of a yoke; circumferentially facing divided parts formed on a radially inner peripheral side of the yoke, each having a dividing line that is oriented in a radial direction and reaches a portion between teeth and divided surfaces that face each other without a gap; and radially facing divided parts formed at the center between the radially inner and outer sides of the yoke along the circumferential direction at the predetermined interval, and each having divided surfaces that face each other in the radial direction, and being continuous at one ends with the respective circumferentially facing divided parts. The circumferentially facing divided parts each have a compressive stress being smaller than a compressive stress acting on the circumferentially deformable part or being zero.

Claims

1. A stator core for a motor including an annular yoke and teeth protruding radially inward from an inner periphery of the yoke, an outer periphery of the yoke attached to an inner periphery of an annular member with a radially inwardly tightening interference, comprising:

a circumferentially deformable part formed on a radially outer peripheral side of the yoke and compressively deformed in a circumferential direction by the tightening interference;

circumferentially facing divided parts formed on a radially inner peripheral side of the yoke, and each having a dividing line that is oriented in a radial direction and reaches a portion between the teeth and divided surfaces that face each other without a gap; and

radially facing divided parts formed between the radially inner and outer sides of the yoke along the circumferential direction at a predetermined interval, each having divided surfaces that face each other in the radial direction, and being continuous at one ends with the respective circumferentially facing divided parts, the divided surfaces moved relative to each other in the circumferential direction by compressive deformation of the circumferentially deformable part, wherein

the circumferentially facing divided parts are in a state of a compressive stress being smaller than a compressive stress acting on the circumferentially deformable part or being zero,

the circumferentially deformable part has a flexible portion for securing an amount of the deformation in the circumferential direction, and

the flexible portion is a convex-concave portion in a thickness direction of the yoke.

2. The stator core according to claim 1, wherein:

the circumferentially deformable part has circumferentially pressed divided parts each having a dividing line oriented in the radial direction and divided surfaces pressed against each other by the tightening interference and being continuous with respective other ends of the circumferentially facing divided parts.

3. The stator core according to claim 1, wherein:

the circumferentially deformable part is a ring part continuous in the circumferential direction.

4. The stator core according to claim 1, wherein:

the circumferentially deformable part includes an outermost periphery of the yoke.

5. The stator core according to claim 1, wherein:

the dividing lines of the circumferentially facing divided parts are oriented to a center of the yoke.

6. The stator core according to claim 2, wherein:

radial lengths of the circumferentially pressed divided parts and the circumferentially facing divided parts are the same.

7. The stator core according to claim 2, wherein:

radial lengths of the circumferentially pressed divided parts are shorter than radial lengths of the circumferentially facing divided parts.

8. The stator core according to claim 2, wherein:

the dividing lines of the circumferentially pressed divided parts are oriented in the radial direction through the respective teeth; and

the dividing lines of the circumferentially facing divided parts are oriented in the radial direction through the respective portions between the teeth.

11. The stator core according to claim 1, wherein:

dividing lines of the radially facing divided parts are set to be inclined so that one ends continuous with the circumferentially facing divided parts are located on an inner peripheral side relative to other ends being closed.

12. A stator core manufacturing method for manufacturing the stator core for a motor according to claim 2, comprising:

a segment processing step of processing a plurality of circumferential stator core segments divided at the circumferentially pressed divided parts, the circumferentially facing divided parts, and the radially facing divided parts; and

an assembly step of joining the plurality of stator core segments annularly in the circumferential direction and attaching the plurality of stator core segments to the inner periphery of the annular member with the radially inwardly tightening interference, thereby pressing the divided surfaces of the respective circumferentially pressed divided parts against each other and facing the divided surfaces of the respective circumferentially facing divided parts without a gap in the circumferential direction.

13. A stator core manufacturing method for manufacturing the stator core for a motor according to claim 3, comprising:

a semi-finished core processing step of forming a semi-finished stator core having the ring part, circumferentially facing divided part correspondents, and radially facing divided part correspondents; and

an assembly step of attaching the semi-finished stator core to the inner periphery of the annular member with the radially inwardly tightening interference, thereby causing compressive deformation of the ring part and facing the divided surfaces of the respective circumferentially facing divided parts without a gap in the circumferential direction.

14. The stator core manufacturing method according to claim 12, wherein:

the attachment to the annular member with the tightening interference is carried out by shrink-fitting.

15. The stator core manufacturing method according to claim 13, wherein:

the attachment to the annular member with the tightening interference is carried out by shrink-fitting.

16. The stator core according to claim 2, wherein:

the circumferentially deformable part includes an outermost periphery of the yoke.

17. The stator core according to claim 3, wherein:

the circumferentially deformable part includes an outermost periphery of the yoke.

18. The stator core according to claim 2, wherein:

the dividing lines of the circumferentially facing divided parts are oriented to a center of the yoke.

19. The stator core according to claim 3, wherein:

the dividing lines of the circumferentially facing divided parts are oriented to a center of the yoke.

20. The stator core according to claim 4, wherein:

the dividing lines of the circumferentially facing divided parts are oriented to a center of the yoke.

9. (canceled)

10. (canceled)