Patent ID: 7360624

Claim:
An electric power steering apparatus, comprising an electric motor for producing a steering assist force, further comprising: a speed reducing mechanism for decelerating a rotation of a rotatable shaft in the electric motor; a converting mechanism for converting an output rotation of the speed reducing mechanism into an axial movement of a steering shaft extending toward right and left sides of a vehicle; a first housing; and a second housing that holds the steering shaft; the speed reducing mechanism, comprising: an input pulley driven by the electric motor and held within the first housing, an output pulley arranged with the steering shaft enclosed thereby, a belt for connecting the input pulley and the output pulley, and means for adjusting a tension of the belt; wherein the means for adjusting the tension includes means for changing a center-to-center distance between the input pulley and the output pulley; and wherein the means for changing the center-to-center distance includes: a guiding mechanism for relatively guiding the first housing and the second housing in a predetermined guiding direction in which the center-to-center distance can be changed; and a compression coil spring which can relatively drive the first and second housings in the predetermined guiding direction.