Patent ID: 8854035

Claim:
A magnetic type rotation detection device comprising: a magnet body which is formed with a magnetic pole pair comprised of an “S”-pole and an “N”-pole and which is provided on a rotation body; a magnetic sensing element which is disposed in a rotation center axial line direction of the rotation body so as to face the magnet body in the rotation center axial line direction; a partition member to which the magnetic sensing element is fixed, the partition member being disposed between the magnet body and the magnetic sensing element; a ring for positioning the magnetic sensing element and the magnet body, the ring being fixed to a face of the partition member on a side where the magnet body is located and is disposed in a non-contact state with the rotation body; and a spacer which is fixed to a stationary body of an apparatus on which the magnetic type rotation detection device is mounted, the spacer being utilized for positioning the ring; wherein a center of the magnetic sensing element is located on a center axial line of the ring, the magnet body is disposed on an inner side of the ring in a non-contact state with the ring, and a center of the magnet body is located on the center axial line of the ring; and wherein the spacer is provided with a through hole in which the magnet body is disposed on an inner side, and an inner diameter dimension of the through hole is same as an outer diameter dimension of the ring, and the ring is fitted into the through hole so that the ring is located between an inner wall of the through hole and an outer peripheral face of the magnet body; wherein the magnetic sensing element is disposed in a recessed part of the partition member which is recessed toward a side where the magnet body is located; the partition member is formed with an annular groove which surrounds the recessed part on a face where the magnet body is located; and an end part of the ring on a side where the magnetic sensing element is located is fitted into the annular groove.