Rotating body mounting device and hard disk manufacturing method

A rotating body mounting device for mounting a rotating body to a rotation shaft, comprising:

• a holding unit that includes a holder having a holding surface directly facing a surface to be held being one side of the plate-shaped rotating body and holds said rotating body to the holding surface-side;
• an actuation mechanism for moving said holder in the axial direction of said rotation shaft, in a state where a mounting hole bored in said rotating body held to said holding surface-side is positioned on an extension line of said rotation shaft;
• and
• a movable shaft having the same axial center as said rotation shaft and whose leading end being one end surface of the movable shaft directly faces an insertion-side end being one end of said rotation shaft;
• wherein said holder is formed with an insertion part opened to said holding surface side to house at least partly an outer peripheral surface of said movable shaft movably in the axial direction and also to allow for insertion of the rotation shaft;
• said actuation mechanism is constituted so as to allow for switching, from one to the other and from the other to the one, between a movable shaft-side mounting state in which at least the leading end of said movable shaft is protruded outwards from said insertion part and in which said rotating body when a movable shaft portion protruded outwards from said insertion part is in the state of being inserted into said mounting hole is held by said holder and a rotation shaft-side mounting state in which said rotating body when said rotation shaft is in the state of being inserted into said mounting hole is held by said holder and in which a portion including the leading end of said movable shaft and the insertion-side end of said rotation shaft is housed in said insertion part;
• said holding unit includes intake equipment that allows air on the side of a surface opposite to said surface to be held in said rotating body to flow in a space between an inner peripheral surface of said insertion part and an outer peripheral surface of said rotation shaft or that of said movable shaft through a space between said mounting hole and the outer peripheral surface of said rotation shaft or that of said movable shaft during said movable shaft-side mounting state or during said rotation shaft-side mounting state, and exhaust equipment that discharges the air from a discharge port opened to the holding surface side toward said surface to be held;
• said intake equipment and said exhaust equipment are constituted so as to cause the intake and exhaust air to hold the rotating body to the holding surface side such that movement of the surface to be held of said rotating body is permitted in non-contact with said holding surface;
• and
• said intake equipment is constituted so as to make Bernoulli effect appear by the intake air during the rotation shaft-side mounting state or during the rotation shaft-side mounting state, thereby moving said rotating body such that the center of said mounting hole is positioned on the axial center of said rotation shaft.