PERMANENT MAGNET FIELD TYPE DC MOTOR WITH BRUSH AND METHOD FOR MANUFACTURING THE SAME

• Main Authors: YAMAUCHI YOSHINORI, SHAO KHUEN
• Format: Patent
• Language: English; Japanese
• Published: 18.10.2022
• Subjects: CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; DYNAMO-ELECTRIC MACHINES; ELECTRICITY; GENERATION

To provide a compact permanent magnet field type DC motor with a brush in which the entire stator is configured by a single permanent magnet, high output is obtained, durability is excellent, and cogging torque characteristics can be improved.SOLUTION: In a small permanent magnet field type DC motor with a brush, one annular permanent magnet has a plurality of axially extending N-pole regions and S-pole regions which are alternately formed in an arc shape. A motor case and the annular permanent magnet are in an interference fit relationship, and a plurality of axially extending concave grooves are provided on the inner peripheral surface of each of the N pole regions and the S pole regions. Each concave groove is provided to extend from a second end portion of the permanent magnet on a farther side from a commutator to a position located axially inward by only a length L from a first end portion of the permanent magnet on a closer side to the commutator on the inner peripheral surface of the permanent magnet. The first end portion of the permanent magnet is an annular non-groove end portion (1144) having no concave groove.SELECTED DRAWING: Figure 3 【課題】ステータの全体を１個の永久磁石で構成し、高出力が得られ、耐久性に優れ、かつ、コギングトルクの特性を向上させることができる、小型の永久磁石界磁型のブラシ付き直流モータを提供する。【解決手段】小型の永久磁石界磁型のブラシ付き直流モータにおいて、1個の環状の永久磁石は、軸方向に伸びる複数のＮ極領域、Ｓ極領域が交互に円弧状に形成されており、モータケースと環状の永久磁石は、締りばめの関係にあり、各Ｎ極領域、Ｓ極領域の内周面には、各々複数個の、軸方向に伸びる凹溝が設けられてている。各凹溝は、永久磁石の内周面でかつ、永久磁石の整流子から遠い側の第２の端部から、永久磁石の記整流子に近い側の第１の端部から軸方向長さＬだけ内側の位置まで設けられている。永久磁石の第１の端部は、凹溝の無い環状の溝無端部（１１４４）となっている。【選択図】図３