Patent ID: 8963390
Filing Date: 2015-02-24
Classification: G11B,H02K

Abstract:
1. A spindle motor comprising: a turntable on which a disc is loaded, a motor which rotates said turntable, wherein a top face plate of a magnetic body rotor case, which rotates united with a rotational shaft of said motor, serves as said turntable, a centering member that guides an inner edge of the disc so as to be concentric with said rotational shaft is disposed on a top face plate of said rotor case, and a clamping magnet disposed in a through-opening on an interior of said centering member and is in contact with the top face plate of said rotor case; wherein said clamping magnet comprises an annular magnet; wherein the inner circumference of said centering member is in contact with the outer circumference of said clamping magnet; wherein said rotational shaft has a protruding portion that protrudes from the top face plate of said rotor case, a cylinder member is fixed around said protruding portion, and the inner circumference of said clamping magnet is in contact with the outer circumference of said cylinder member, and the clamping magnet is disposed concentrically with said rotational shaft; and wherein said cylinder member has a flange that protrudes radially at the top outer circumference, and said flange faces, in the axial direction, the top face of said clamping magnet.