An electric power steering apparatus includes a rolling bearing 9 for
supporting rotatably a worm 6 that is rotated by a steering assisting
electric motor 5; a first resilient portion 21 which is disposed in
contact with the inner circumference of an inner ring 9b of the rolling
bearing 9 and held on the worm 6 so that it is extendable by a force in an
axial direction applied to the worm 6; and two resilient members 22 and
23, held in contact with both ends of the inner ring 9b, for restraining
the movement of the worm 6 in the axial direction. Even when the electric
power steering apparatus has a single rolling bearing, the worm 6 is moved
in the axial direction by a steering force transmitted to the worm 6 from
a worm wheel 7 in a steering range in which the motor 5 is not driven, and
the steering load in the steering range in which the motor 5 is not driven
is decreased.
