Abstract: The clutch hub includes a sheet-metal hub member which has an axial member projected from the center of its plate surface, and also includes an annular armature which is fixed to an outer peripheral portion of the axial member. First mounting the axial member of the clutch hub downward on a support member and thereby elastically supporting the end surface of the armature by the support member; holding the axial member of the clutch hub using a chuck; locating a fixing member just under a portion of a maximum runout portion of an inner hub; contacting a cylindrical end surface of a pressing member with an upper surface of the inner hub using pressure; and plastically deforming the inner hub by a pressing force of the pressing member using the locating portion of the fixing member as a fulcrum, which thereby corrects an inclination of the axial member.

Abstract: The clutch hub includes a sheet-metal hub member which has an axial member projected from the center of its plate surface, and also includes an annular armature which is fixed to an outer peripheral portion of the axial member. First mounting the axial member of the clutch hub downward on a support member and thereby elastically supporting the end surface of the armature by the support member; holding the axial member of the clutch hub using a chuck; locating a fixing member just under a portion of a maximum runout portion of an inner hub; contacting a cylindrical end surface of a pressing member with an upper surface of the inner hub using pressure; and plastically deforming the inner hub by a pressing force of the pressing member using the locating portion of the fixing is member as a fulcrum, which thereby corrects an inclination of the axial member.

Abstract: A bearing 41 of a support portion 4 for rotatably supporting a shaft 11 of a rotating body 10 to be measured with respect to the magnitude of unbalance thereof is formed into a hollow U-shape and has formed therein an injection port 41b for injecting a gas towards the shaft. As the shaft can be supported and floats without making contact with the bearing by virtue of the gas injected from the injection port, the friction can be made small and, hence, a change in rotational speed can be made small. The number and position of the injection ports are determined as required.

Abstract: A bearing 41 of a support portion 4 for rotatably supporting a shaft 11 of a rotating body 10 to be measured with respect to the magnitude of unbalance thereof is formed into a hollow U-shape and has formed therein an injection port 41b for injecting a gas towards the shaft. As the shaft can be supported and floats without making contact with the bearing by virtue of the gas injected from the injection port, the friction can be made small and, hence, a change in rotational speed can be made small. The number and position of the injection ports are determined as required.