Patent ID: 8004132
Filing Date: 2011-08-23
Classification: H02K

Abstract:
1. A coreless motor comprising: (a) an outer cylinder gear unit including a planetary gear unit, an inner yoke formed with an internal gear in mesh with planetary gears of the planetary gear unit, a cylindrical magnet disposed on an outer periphery of the inner yoke, and an outer cylinder disposed on an outer periphery of the magnet; (b) a motor shaft unit including an inner lid adapted to be attached to the inner yoke, a motor shaft mounted with a pinion gear engageable with the planetary gears of the planetary gear unit when the inner lid is attached to the inner yoke, and a pair of bearings adapted to journal the motor shaft for rotation relative to the inner lid; (c) a rotor unit including a circular plate adapted to be attached to the motor shaft, a commutator attached to the circular plate, and a cylindrical coil fixed to the circular plate and electrically connected with the commutator; and (d) an outer lid unit including an outer lid adapted to be attached to the outer cylinder, and brushes fixed to the outer lid and adapted to be in contact with the commutator when the outer lid is attached to the outer cylinder, wherein the inner lid is attached to the inner yoke such that the pinion gear is in mesh with the planetary gears of the planetary gear unit, the circular plate is then attached to the motor shaft such that the coil is interposed between the magnet and the outer cylinder, and then the outer lid is attached to the outer cylinder.