Magnetic disk drive device, magnetic disk assembly and methods of forming the same

A magnetic disk assembly comprising:

• a magnetic disk, the magnetic disk comprising a first surface and a second surface opposite to the first surface;
• and
• a magnetic disk drive device for rotary driving the magnetic disk, the magnetic disk drive device comprising:
• a drive motor for rotary driving the magnetic disk, the drive motor comprising a motor hub which has a motor hub support portion with a screw-type motor hub engaging portion and with a motor hub support surface for supporting the magnetic disk at a first magnetic disk surface;
• and
• a clamp disk comprising a clamp disk support portion with a screw-type clamp disk engaging portion complementary to the motor hub engaging portion so that the clamp disk and the motor hub are connectable to each other via a screw engagement between the motor hub engaging portion and the clamp disk engaging portion, and with a clamp disk support surface for supporting the magnetic disk at a second magnetic disk surface opposite the first magnetic disk surface, the clamp disk support surface facing the motor hub support surface when the clamp disk and the motor hub are in screw engagement, thereby allowing the magnetic disk to be supported between the motor hub and the clamp disk in a clamping manner by being clamped in between the motor hub support surface and the clamping disk support surface,
• wherein the motor hub support portion has a radial circumferential motor hub shoulder limiting an inner circumference of the motor hub support surface,
• wherein the clamp disk support portion has a radial circumferential clamp disk shoulder limiting an inner circumference of the clamp disk support surface,
• wherein an axial height of the motor hub shoulder as well as an axial height of the clamp disk shoulder are respectively smaller than a thickness of the magnetic disk, and wherein the clamp disk shoulder and the motor hub shoulder are radially flush when the motor hub and the clamp disk are engaged with each other so as that, when the magnetic disk is clamped between the motor hub and the clamp disk, an inner circumferential wall of the magnetic disk radially abuts both the motor hub shoulder and the clamp disk shoulder.

A magnetic disk drive device for rotary driving a magnetic disk, the magnetic disk drive device comprising:

• a drive motor for rotary driving the magnetic disk, the drive motor comprising a motor hub which has a motor hub support portion with a screw-type motor hub engaging portion and with a motor hub support surface for supporting the magnetic disk at a first magnetic disk surface;
• and
• a clamp disk comprising a clamp disk support portion with a screw-type clamp disk engaging portion complementary to the motor hub engaging portion so that the clamp disk and the motor hub are connectable to each other via a screw engagement between the motor hub engaging portion and the clamp disk engaging portion, and with a clamp disk support surface for supporting the magnetic disk at a second magnetic disk surface opposite the first magnetic disk surface, the clamp disk support surface facing the motor hub support surface when the clamp disk and the motor hub are in screw engagement, thereby allowing the magnetic disk to be supported between the motor hub and the clamping disk in a clamping manner by being clamped in between the motor hub support surface and the clamp disk support surface,
• wherein the motor hub has a disk-shaped top yoke which is attached to a motor shaft of the drive motor and on which the motor hub engaging portion and the motor hub support surface are provided, and
• wherein the top yoke is detachably attached to the motor shaft by means of a screw connection which is concentric with respect to a longitudinal axis of the motor shaft.