A motor assembly comprising: a casing formed of a first housing and a second housing, the first housing is a box-shaped having an opening section, and the second housing is configured to close the opening section of the first housing by covering said opening section; a motor received in the first housing; a speed reducer received in the first housing and that reduces rotation of the motor and outputs the reduced rotation, a conduction section formed on an inner side surface of the first housing to be laid along the inner side surface, and a connecting section into which an end portion of the conduction section is able to be inserted, said connecting section being formed on an inner side surface of the second housing, wherein a board disposed in the first housing and a board disposed in the second housing can be electrically connected by the conduction section and the connecting section, wherein the motor is an outer rotor brushless type motor; wherein the stator of the motor has an annular stator core positioned and fixed inside the first housing and comprises:. a plurality of tooth section extending from the stator core in a radial outward direction, wherein each of the tooth section is in a substantial T-shape having a tooth main body integrally formed with a flange section, the tooth main body extending in said radial direction and the flange section extending from the tip of the tooth main body in the circumferential direction;. windings wound on each of the tooth section respectively, according to a 3-phases structure; and. a terminal holder in one tooth section of each phase of the 3-phases structures, the terminal holder being formed on an end surface of the flange section of said one tooth section, each terminal holder having a terminal connecting the winding to the conduction section. a casing formed of a first housing and a second housing, the first housing is a box-shaped having an opening section, and the second housing is configured to close the opening section of the first housing by covering said opening section; a motor received in the first housing; a speed reducer received in the first housing and that reduces rotation of the motor and outputs the reduced rotation, a conduction section formed on an inner side surface of the first housing to be laid along the inner side surface, and a connecting section into which an end portion of the conduction section is able to be inserted, said connecting section being formed on an inner side surface of the second housing, wherein a board disposed in the first housing and a board disposed in the second housing can be electrically connected by the conduction section and the connecting section, wherein the motor is an outer rotor brushless type motor; wherein the stator of the motor has an annular stator core positioned and fixed inside the first housing and comprises:. a plurality of tooth section extending from the stator core in a radial outward direction, wherein each of the tooth section is in a substantial T-shape having a tooth main body integrally formed with a flange section, the tooth main body extending in said radial direction and the flange section extending from the tip of the tooth main body in the circumferential direction;. windings wound on each of the tooth section respectively, according to a 3-phases structure; and. a terminal holder in one tooth section of each phase of the 3-phases structures, the terminal holder being formed on an end surface of the flange section of said one tooth section, each terminal holder having a terminal connecting the winding to the conduction section.. a plurality of tooth section extending from the stator core in a radial outward direction, wherein each of the tooth section is in a substantial T-shape having a tooth main body integrally formed with a flange section, the tooth main body extending in said radial direction and the flange section extending from the tip of the tooth main body in the circumferential direction;. windings wound on each of the tooth section respectively, according to a 3-phases structure; and. a terminal holder in one tooth section of each phase of the 3-phases structures, the terminal holder being formed on an end surface of the flange section of said one tooth section, each terminal holder having a terminal connecting the winding to the conduction section.