Patent ID: 7235905

Claim:
An electric power steering assembly comprising: an electric motor providing steering assist; a reduction mechanism for speed reduction of an output rotation of the electric motor; and a reduction-mechanism housing accommodating therein the reduction mechanism. the electric motor including: an output shaft rotatably supported by the reduction-mechanism housing; a rotor having an outer periphery provided with a plurality of rotor magnets and being rotatable integrally with the output shaft; a motor housing having a cylindrical portion with an inner periphery surrounding the outer periphery of the rotor; an annular space defined between the outer periphery of the rotor and the inside circumference of the motor housing; and an annular stator assembly accommodated in the annular space, the motor housing being formed integrally with the reduction-mechanism housing; the motor housing including an end portion disposed on an opposite side from the reduction-mechanism housing, the end portion of the motor housing defining an opening having a size to allow the stator assembly to be assembled in the motor housing, the electric motor including a cover for closing the opening at the end portion of the motor housing, the stator assembly including a cylindrical stator yoke having an inside circumference and an outside circumference, and being fixed in the motor housing, the inner periphery of the cylindrical portion of the motor housing including a cylindrical guide portion, an outer periphery of a stator yoke including a cylindrical surface as a guided portion, and wherein when the stator assembly is assembled in the annular space via the opening at the end portion of the motor housing, the cylindrical surface of the outer periphery of the stator yoke is guided by the cylindrical surface of the inner periphery of the cylindrical portion of the motor housing so as to prevent the stator assembly from contacting the rotor, further comprising a rotation angle detecting member for sensing a rotation angle of the output shaft, the rotation angle detecting member including a movable portion rotatable integrally with the output shaft, and an annular stationary portion surrounding the movable portion, wherein the electric motor includes a cover-assembly including a plurality of elements, wherein the plural elements includes the cover as a first element, and the stationary portion of the rotation angle detecting member, as a second element, and wherein the cover is assembled to the motor housing in a manner to be adjustable for its circumferential position with respect to the motor housing, the cover adjusted for position thereby accomplishing adjustment for relative positions between the movable portion and the stationary portion of the rotation angle detecting member.