Patent ID: 7088022

Claim:
An axial air-gap vibration motor, comprising: an eccentric rotor comprising: a printed wiring board having a first side and an opposing second side; a commutator disposed on a first side and air-core armature connecting lands interconnected with the commutator; a bearing mounted to the printed wiring board at a center of rotation of the rotor; a first air-core armature coil disposed at the second side of the printed wiring board; a second aircore armature coil disposed at the second side of the printed wiring board and overlapping the first air-core armature coil in an axial direction of the rotor and shifted in a first rotational direction relative to the first air-core armature in a range of 15° to 60°; a third air-core armature coil disposed at the second side of the printed wiring board and so as to not overlap the first air-core armature coil and shifted in a second rotational direction, opposite said first rotational direction, relative to the first air-core armature at least about 120°, to not overlay said first and second air-core armature coils; the first, second and third air-core armature coils being eccentrically disposed at the second side of the printed wiring board relative to the center of rotation of the rotor and interconnected with the air-core armature connecting lands; and an eccentric weight disposed at the second side of the printed wiring board, eccentric with respect to the center of rotation of the rotor, and in a common radial plane with the second air-core armature coil and outside of said second air-core armature coil; a housing assembly including a casing and a bracket; a shaft supported in the housing assembly and rotatable supporting said rotor via said bearing; a magnet disposed in the housing assembly so as to define an axial air-gap in conjunction with the first, second and third air-core armature coils, and the first, second and third air-core armature coils having an angle section equal to a pitch angle of magnetization of the magnet; and a brush disposed in the housing assembly engaging the commutator so as to supply current to the first, second and third air-core armature coils.