Abstract: An electric power steering apparatus comprises a ball nut rotationally driven by an electric motor through a gear train and having a female thread groove formed in the inner periphery thereof, a rack shaft disposed through the ball nut on the axis thereof and having a male thread groove so formed in its outer periphery as to face to the female thread groove, a ball screw mechanism having a number of circulation balls interposed between the female thread groove and the male thread groove, and a housing for holding the ball nut rotatably through the bearing. An elastic member is interposed between the housing and the ball nut in order to permit the ball nut to make a predetermined displacement.

Abstract: An electric power steering apparatus comprises an electric motor having a motor housing, a ball screw mechanism connected to the electric motor through power transmission means and used for driving a rack shaft, and a steering gear case encasing the rack shaft and the ball screw mechanism. The electric motor is supported by at least two supporting portions with respect to the steering gear case, and is supported by at lest one of the two supporting portions through an elastic member.

Abstract: An electric power steering apparatus comprises a rotary shaft member connected to a steering wheel and rotating together with the steering wheel, an elongate member capable of making a rectilinear motion in either of opposite directions in order to steer dirigible wheels, a rack-and-pinion mechanism, a ball screw mechanism constructed of a screw member provided in a second axial position of the elongate member, a nut member surrounding at least a part of the screw member and a multiplicity of balls interposed between the screw member and the nut member, an electric motor unit disposed with its axis different from that of the elongate member, and a meshing type rotation decelerating mechanism including at least two pieces of meshing components in order to decelerate rotation of an output shaft of the electric motor unit and to transfer the decelerated rotations to the nut member of the ball screw mechanism, wherein a contact portion, with the other component, of at least the one component of the components of