Patent ID: 7665378

Claim:
An electric power steering apparatus comprising: an electric motor for steering assist; a transmission mechanism for transmitting an output from the electric motor to a steering mechanism, the transmission mechanism including a driving gear having a center axis, a driven gear having a center axis, and an intermediate gear meshed with the driving gear and with the driven gear, the intermediate gear having a center axis disposed in parallel to the center axis of the driving gear and the center axis of the driven gear; a housing accommodating the transmission mechanism therein; and an eccentric mechanism for eccentrically locating the intermediate gear in order that the center axis of the intermediate gear is moved toward at least one of the center axis of the driving gear and the center axis of the driven gear while maintaining the parallel relation, wherein the housing is formed with first and second circle holes, the first and second circle holes have center axes aligned coaxially with each other; the eccentric mechanism includes an intermediate-gear support shaft having a center axis; the intermediate-gear support shaft is supported by the first and second circle holes of the housing in a manner to be rotatable about its center axis of the intermediate-gear support shaft for adjustment of a rotational position thereof; the intermediate-gear support shaft includes an outer periphery; the outer periphery of the intermediate-gear support shaft includes an eccentric portion comprising a cylindrical surface eccentric to the center axis of the intermediate-gear support shaft; and the intermediate gear is rotatably supported by the eccentric portion wherein the intermediate-gear support shaft includes first and second ends; the first end of the intermediate-gear support shaft is provided with an end plate rotatable together with the intermediate-gear support shaft; the end plate includes an outer periphery; the outer periphery of the end plate includes a fit-engagement portion removably fitted in the first circle hole; and an inside diameter of the first circle hole is larger than an outside diameter of the intermediate gear.