Stator for an electric motor

• US 5,729,072 A
• Filed: 09/20/1993
• Issued: 03/17/1998
• Est. Priority Date: 09/24/1992
• Status: Expired due to Term

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Takeuchi, Manabu, Yamanaka, Hideki, Morita, Kazunori, Nakatsukasa, Koichi, Fukuda, Kouzi, Akiyama, Takashi, Kikuchi, Seiji, Kawazoe, Hiroshi, Hirano, Mikio
• Primary Examiner(s): Stephan, Steven L.
• Assistant Examiner(s): JONES, JUDSON
• Application Number:
  US08/123,383
• Time in Patent Office: 1,639 Days
• Field of Search: 310/217, 310/254, 310/258, 310/179, 310/216, 310/218, 310/42
• US Class Current: 310/216.009
• CPC Class Codes: H02K 1/148 Sectional cores H02K1/141 takes precedence

Abstract

In a stator for an electric motor, insulating members are formed on laminated iron cores divided for each pole-tooth unit in the direction of the output shaft and windings are applied perpendicularly to the pole-tooth portions in a high-density alignment. After a predetermined number of the laminated iron cores are combined so as to form a cylindrical configuration, they are welded at the outer end portions of the dividing surfaces in the direction of lamination so as to construct an integral structure stator with rigidity, thereby enabling high densification of the windings (conductor space factor of 70%) and space-savings in the winding end portions. Further, as any joint portions between the pole-tooth portions are not necessary, reduction (5 to 10%) in motor efficiency due to such joint portions can be prevented, and, as any integrally forming by resinous members is not necessary, inter-winding short-circuiting is not caused. Welding may be replaced by adhesive bonding. Otherwise, an annular member may be employed to form an integral structure of the divided iron core lamination.

Claims

1. A stator for an electric motor, said stator comprising:

a plurality of cores, each of the plurality of cores corresponding to a pole-tooth unit of the electric motor and comprising a pole-tooth portion and an outer portion with an outer surface and dividing surfaces, said dividing surfaces extending parallel to a longitudinal axis of said electric motor, said plurality of cores being arranged in a cylindrical configuration, and adjacent ones of said plurality of cores being rigidly fixed together along said dividing surfaces; and

windings wound around the pole-tooth portions of the plurality of cores such that each of the windings is wound around a single one of the pole-tooth portions;

wherein the plurality of cores are bonded at the dividing surfaces.

4. A stator according to claim 1, further comprising an annular member arranged on the outer surface of each of the plurality of cores to hold the plurality of cores in the cylindrical configuration and to urge the plurality of cores inwardly.

2. A stator for an electric motor, said stator comprising:

a plurality of cores, each of the plurality of cores corresponding to a pole-tooth unit of the electric motor and comprising a pole-tooth portion and an outer portion with an outer surface and dividing surfaces, said dividing surfaces extending parallel to a longitudinal axis of said electric motor, said plurality of cores being arranged in a cylindrical configuration, and adjacent ones of said plurality of cores being rigidly fixed together along said dividing surfaces; and

windings wound around the pole-tooth portions of the plurality of cores such that each of the windings is wound around a single one of the pole-tooth portions;

wherein the plurality of cores are welded together along the dividing surfaces.

5. A stator according to claim 2, further comprising an annular member arranged on the outer surface of each of the plurality of cores to hold the plurality of cores in the cylindrical configuration and to urge the plurality of cores inwardly.

7. A stator according to claim 2, further comprising an annular member arranged on the outer surface of each of the plurality of cores to hold the plurality of cores in the cylindrical configuration and to urge the plurality of cores inwardly, and wherein each of the plurality of cores comprises a projection and an indentation at said outer portion, said adjacent ones of said plurality of cores being engaged by means of said projection and said indentation.

3. A stator for an electric motor, said stator comprising:

a plurality of cores, each of the plurality of cores corresponding to a pole-tooth unit of the electric motor and comprising a pole-tooth portion and an outer portion with an outer surface and dividing surfaces, said dividing surfaces extending parallel to a longitudinal axis of said electric motor, said plurality of cores being arranged in a cylindrical configuration, and adjacent ones of said plurality of cores being rigidly fixed together along said dividing surfaces; and

windings wound around the pole-tooth portions of the plurality of cores such that each of the windings is wound around a single one of the pole-tooth portions;

wherein each of the plurality of cores comprises a projection and an indentation at said outer portion, said adjacent ones of said plurality of cores being engaged by means of said projection and said indentation.

6. A stator according to claim 3, further comprising an annular member arranged on the outer surface of each of the plurality of cores to hold the plurality of cores in the cylindrical configuration and to urge the plurality of cores inwardly.