Patent ID: 8400144

Claim:
A rotational position sensor to detect the rotational angle of a shaft, comprising: a housing including a bearing portion; a rotating body rotatably supported by the bearing portion around a predetermined axis line; and a sensor unit including a movable sensor element arranged at the rotating body to detect a rotational angle position of the rotating body and a fixed sensor element arranged at the housing, the movable sensor element and the fixed sensor element being arranged at a center area centered on the axis line, wherein the rotating body includes an annular contact face having the axis line as the center, the bearing portion includes an annular bearing face having the axis line as the center and receiving the annular contact face, at least one of the annular contact face and the annular bearing face is formed to be a tapered annular face which defines a part of a virtual cone face having a vertex on the axis line, and the annular contact face and the annular bearing face are outside the center area in which the movable sensor element and the fixed sensor element are arranged.