Abstract: A rotating portion includes a hollow shaft extending along a central axis. The hollow shaft includes a through hole passing therethrough in an axial direction. The rotating portion includes an upper screw to close an upper opening that is an opening at an upper end portion of the through hole. The rotating portion includes a lower screw to close a lower opening that is an opening at a lower end portion of the through hole. The hollow shaft includes an upper groove portion into which the upper screw is screwed at the upper opening. The hollow shaft includes a lower groove portion into which the lower screw is screwed at the lower opening. A lubricating oil is in contact with the lower screw. The lower groove portion is shorter in axial length than the upper groove portion, and the lower screw is smaller in axial pitch than the upper screw.

Abstract: A yoke includes a first cylindrical unit held by a radially outside surface of a rotor base, a yoke annular unit extending radially outwardly from an axially lower end of the first cylindrical unit, and a second cylindrical unit extending axially downward from a radially outer end of the yoke annular unit, and a magnet fixed to a radially inside surface of the second cylindrical unit.

Abstract: A rotating portion includes a hollow shaft extending along a central axis. The hollow shaft includes a through hole passing therethrough in an axial direction. The rotating portion includes an upper screw to close an upper opening that is an opening at an upper end portion of the through hole. The rotating portion includes a lower screw to close a lower opening that is an opening at a lower end portion of the through hole. The hollow shaft includes an upper groove portion into which the upper screw is screwed at the upper opening. The hollow shaft includes a lower groove portion into which the lower screw is screwed at the lower opening. A lubricating oil is in contact with the lower screw. The lower groove portion is shorter in axial length than the upper groove portion, and the lower screw is smaller in axial pitch than the upper screw.

Abstract: {circle around (1)} A spindle motor includes a fixing portion defined by a bearing portion, a holder portion, a gap between the bearing portion and the holder portion, and an adhesive arranged in the gap. {circle around (2)} The fixing portion includes first and second protruding surfaces arranged to protrude radially from a first and a second one, respectively, of an outside surface of the bearing portion and an inside surface of the holder portion; and first and second boundary surfaces arranged to join the first and second surfaces, respectively, to the first and second protruding surfaces, respectively. {circle around (3)} At least a portion of the first boundary surface is arranged above the second boundary surface. {circle around (4)} The first and second protruding surfaces are arranged radially opposite to the second and first surfaces, respectively, with a first and a second gap, respectively, intervening therebetween.

Abstract: {circle around (1)} A spindle motor includes a fixing portion defined by a bearing portion, a holder portion, a gap between the bearing portion and the holder portion, and an adhesive arranged in the gap. {circle around (2)} The fixing portion includes first and second protruding surfaces arranged to protrude radially from a first and a second one, respectively, of an outside surface of the bearing portion and an inside surface of the holder portion; and first and second boundary surfaces arranged to join the first and second surfaces, respectively, to the first and second protruding surfaces, respectively. {circle around (3)} At least a portion of the first boundary surface is arranged above the second boundary surface. {circle around (4)} The first and second protruding surfaces are arranged radially opposite to the second and first surfaces, respectively, with a first and a second gap, respectively, intervening therebetween.