Patent ID: 7498803
Filing Date: 2009-03-03
Classification: G01D,G05G

Abstract:
1. A rotation angle detection device for detecting a rotation angle of an object, the rotation angle detection device comprising: a yoke which has a substantially cylindrical shape and is made of a magnetic metal, the yoke being fixedly mounted at the object to be rotatable integrally with the object; a magnetism generation unit which is fixedly mounted at an inner surface of the yoke and generates a magnetic field substantially perpendicular to a center axis of the yoke; a magnetism detection member which generates an output corresponding to a variation of the magnetic field, to detect a relative rotation angle between the yoke and the magnetism detection member, the magnetism detection member being arranged at an inner side of the yoke and positioned substantially along the center axis of the yoke; at least a first bearing and a second bearing which rotatably support the yoke; and a support member which holds the bearing to rotatably support the object, wherein: the yoke is fixed to the object with an outer surface of the yoke contacting the object; the yoke is rotatably supported by the first bearing and the second bearing; and the magnetism generation unit and the object are arranged between the first bearing and the second bearing in a rotation axis direction of the object.