Patent ID: 8511418

Claim:
An electric power steering system, comprising: an upper shaft that is connected to a steering wheel; a lower shaft that is coaxially connected to the upper shaft via a torsion bar; an electric motor that is driven and controlled, based on a torque applied to the steering wheel; a speed reduction mechanism that includes a worm and a worm wheel reducing the speed of rotation of the electric motor and transmitting it to the lower shaft; an upper housing that houses one end of the upper shaft and one end of the lower shaft; a lower housing that houses the speed reduction mechanism and the other end of the lower shaft; a fitting portion where a lower end of the upper housing and an upper end of the lower housing are loose-fitted with each other; a bolt that fastens the upper housing and the lower housing; and a gap adjustment mechanism that is disposed in the fitting portion and moves the upper housing to the lower housing in a direction perpendicular to an axis of the upper shaft and the lower shaft before fitting the upper housing and the lower housing by the bolt.