Abstract: A manufacturing method of a cover by bending a non-magnetic metal sheet, the cover being provided between an annular magnet fixed to a rotary member and a magnetic sensor detecting magnetism generated from the annular magnet, and a press die having a first die and a second die configured to be able to approach to and depart from each other. The method includes a bending step of bending the metal sheet by using a forming machine of which contact portion with the metal sheet is a non-magnetized portion. The press die presses and bends a non-magnetic metal sheet, and the first die and the second die include non-magnetic portions on a part of press faces configured to press the metal sheet, respectively, the non-magnetic portions facing each other.

Abstract: A manufacturing method of a cover by bending a non-magnetic metal sheet, the cover being provided between an annular magnet fixed to a rotary member and a magnetic sensor detecting magnetism generated from the annular magnet, and a press die having a first die and a second die configured to be able to approach to and depart from each other. The method includes a bending step of bending the metal sheet by using a forming machine of which contact portion with the metal sheet is a non-magnetized portion. The press die presses and bends a non-magnetic metal sheet, and the first die and the second die include non-magnetic portions on a part of press faces configured to press the metal sheet, respectively, the non-magnetic portions facing each other.

Abstract: A sealing structure for a fitting portion where an annular member is concentrically fitted to a cylindrical member to be fitted at a cylindrical part of the annular member is disclosed. The sealing structure is characterized by an elastic annular seal layer integrally provided on the backward end part of the annular member or the cylindrical member in fitting direction, by applying elastomeric agent to the backward end part and hardening it, and the elastic annular seal layer is formed such that it has layer thickness of 5 ?m to 1 mm and is interposed in a compressed state between the annular member and the cylindrical member when said annular member is fitted to said cylindrical member.