Patent ID: 7332843

Claim:
A motor attached to a driven device to drive the driven device, the driven device including a housing member, the motor comprising: a cylindrical yoke housing that has a bottom wall at one end and an opening at the other end, the driven device being attached to the side of the yoke housing where the opening is formed; a rotor accommodated in the yoke housing, wherein the rotor includes a rotary shaft, an armature, and a commutator, the armature having a core and a coil wound about the core, wherein the armature and the commutator are fixed to the rotary shaft; a bearing that supports the rotary shaft, wherein the armature, the commutator, and the bearing are arranged on the rotary shaft in this order in a first direction from the bottom wall toward the opening; a base plate attached to the opening of the yoke housing, wherein the base plate has a through hole into which the bearing is inserted such that the bearing is movable in the axial direction relative to the through hole, and the commutator has an outer diameter greater than an inner diameter of the through hole; and an urging member that urges the rotor in the first direction, wherein, in a state where the driven device is not attached to the yoke housing, the urging member urges the rotor so as to press the commutator against a portion of the base plate about the through hole while a part of the bearing is exposed from the base plate, the exposed part of the bearing including an end face and a part of an outer circumferential surface, and wherein, when the driven device is attached to the yoke housing, the housing member pushes the end face of the bearing while holding the part of the outer circumferential surface, so as to move the rotor in a second direction opposite to the first direction against the urging force of the urging member so that the commutator separates from the base plate.