Patent ID: 7413052

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; and 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, the speed reducing mechanism comprising an input pulley rotatably coupled to an input shaft driven by the electric motor, an output pulley arranged with the steering shaft enclosed thereby, a belt for connecting the input pulley and the output pulley, and a mechanism for adjusting a tension of the belt, the mechanism for adjusting the tension including a mechanism for changing a center-to-center distance between the input pulley and the output pulley, the mechanism for changing the center-to-center distance including: a guiding mechanism for relatively guiding a first housing for holding the input pulley and a second housing for holding the steering shaft in a predetermined guiding direction in which the center-to-center distance can be changed, the guiding mechanism comprising: a connection housing comprising: a peripheral wall substantially parallel to the input shaft; a first guided section comprising a first annular flange extending away from both the peripheral wall and the input shaft; a first end wall extending away from the peripheral wall and extending towards the input shaft; an extension section substantially parallel to the input shaft and extending away from the first end wall, the extension section comprising a first aperture defined therein; a second end wall substantially parallel to the first end wall and extending away from a front end of the extension section and extending towards the input shaft; and a cylindrical section extending away from the second end wall having a substantially stepped-shape that defines a second guided section, the cylindrical section is rotatably coupled to a second end of the input shaft using a bearing; and a speed reducing mechanism housing integrally formed with the second housing, the speed reducing mechanism comprising: a first guiding section comprising a second annular flange that facilitates guiding the first guided section; a second guiding section comprising a third end wall extending substantially perpendicularly away from the first guiding section, the third wall comprising a recess defined therein that facilitates guiding the second guided section of the cylindrical section; and a peripheral wall extending substantially perpendicularly away from the third end wall, the peripheral wall comprising a second aperture defined therein that receives a screw that is threadably coupled to the extension section using the first aperture such that the screw facilitates driving the first and second housings in the predetermined guiding direction, which facilitates adjusting the center-to-center distance and the tension of the belt.