Patent ID: 7576457

Claim:
An electric power steering apparatus comprising: a DC brush motor controlled by a control apparatus configured to compensate for an influence of an inertia, the DC brush motor comprising: an output shaft rotatably supported by a first bearing and a second bearing, the first bearing comprising an outer ring contained by a clearance fitting in an inner face of a bearing containing portion formed in a yoke having a bottomed cylinder shape, and the second bearing comprising an outer ring fixed to a housing to which an opening side of the yoke is fixed and an inner ring fixed by being pinched in an axial direction, and a boss arranged between the output shaft of the DC brush motor and an input shaft driven by the DC brush motor, fixed to an end portion of the output shaft which is projected from the second bearing in the axial direction, and for transmitting a rotational force of the DC brush motor from the output shaft to the input shaft by the boss, wherein a weight of the boss is made to be equal to or larger than 10% of a weight of a rotor of the DC brush motor.