Patent ID: 6744169
Filing Date: 2004-06-01
Classification: H01R,H02K

Abstract:
A direct current motor, comprising:a stator for generating a magnetic field therein; a rotor rotating inside the stator, the rotor including an armature core and armature coils held in the armature core; a commutator connected to the rotor, the commutator including a plurality of commutator segments circularly arranged and bonded together with an insulation bond; brushes slidably contacting the commutator for supplying electric current to the armature coils; and a housing containing the stator, the rotor and the brushes therein, wherein: each commutator segment comprises: a contacting portion contacting the brushes, the contacting portion being elongated in an axial direction of the commutator; a connecting portion having a slot open to a radial outside of the commutator, the connecting portion being extended in a radial direction of the commutator from one end of the contacting portion, ends of the armature coils being forcibly inserted into the slot from the radial outside of the slot and electrically connected thereto; a projecting portion embedded in the insulation bond, the projecting portion being projected from a foot portion of the connecting portion in an opposite axial direction to the axial direction in which the contacting portion is elongated; and an anchor portion embedded in the insulation bond, the anchor portion being formed at a radial side of the contacting portion, the anchor portion including a first depressed portion formed at one longitudinal end of the anchor portion remote from the connecting portion and a second depressed portion formed at the other longitudinal end of the anchor portion directly underneath the connecting portion; a first circular groove is formed by the first depressed portions when the plurality of the commutator segments are circularly arranged, and a first circular band is disposed in the first circular grove; and a second circular groove is formed by the second depressed portions when the plurality of the commutator segments are circularly arranged, and a second circular band is disposed in the first circular groove.