Manufacturing method of disk drive device capable of reducing amount of unbalance, disk drive device and subassembly thereof
A disk drive device is provided with a recording disk, a base member, a bearing unit, and a hub member. In a marking step, unbalance information indicating the displacement of the center of gravity of the hub member with respect to the rotation center of the hub member is acquired, and an information mark containing the unbalance information is applied to at least the hub member or the base member. In an installing and adjustment step, the unbalance information is read form the information mark, and the position for installing the recording disk in an outer cylinder part is determined in accordance with the unbalance information so as to install the recording disk on the hub member.
1. A subassembly of a disk drive device comprising:
a base member;
a bearing unit arranged on the base member; and
a hub member that has both an outer cylinder part extending in the axial direction of the bearing unit for holding a recording disk and an outward extension portion formed continuously with the outer cylinder part and extending outward in the radial direction of the recording disk and that is rotatably supported by the bearing unit, wherein
at least one of the hub member and the base member has an information mark containing an axial run-out information indicating the axial run-out of the outward extension portion.
2. The subassembly of a disk drive device according to claim 1 comprising a radial fluid dynamic bearing having a radial dynamic pressure groove arranged at the same height as or higher than the surface of the outward extension portion in the axial direction on which the recording disk is mounted.
3. The subassembly of a disk drive device according to claim 1 , wherein the information mark indicates, by a polar coordinate system, the axial run-out information indicating the axial run-out of the outward extension portion.
4. The subassembly of a disk drive device according to claim 1 , wherein the information mark indicates the direction of the maximum position of the axial run-out.
5. The subassembly of a disk drive device according to claim 1 , wherein the information mark is indicated by a barcode including at least two segments into which the axial run-out information is encoded indicating the axial run-out of the outward extension portion.
6. The subassembly of a disk drive device according to claim 1 , wherein the information mark contains individual identification information of the subassembly of the disk drive device.
7. The subassembly of a disk drive device according to claim 1 , wherein the information mark contains manufacturing related information of the hub member.
8. The subassembly of a disk drive device according to claim 1 , wherein the information mark contains manufacturing related information of the bearing unit.
9. The subassembly of a disk drive device according to claim 1 , wherein the information mark contains NRRO information of the subassembly of the disk drive device.
10. The subassembly of a disk drive device according to claim 1 , wherein the information mark contains information regarding back electromotive force generated in a drive coil of the subassembly of the disk drive device.
11. The subassembly of a disk drive device according to claim 1 , wherein the information mark contains manufacturing related information of a magnet of the disk drive device.
12. A disk drive device comprising:
a recording disk;
a base member;
a bearing unit arranged on the base member; and
a hub member that has both an outer cylinder part extending in the axial direction of the bearing unit for holding the recording disk and an outward extension portion formed continuously with the outer cylinder part and extending outward in the radial direction of the recording disk and that is rotatably supported by the bearing unit, wherein
at least one of the hub member and the base member has an information mark containing an axial run-out information indicating the axial run-out of the outward extension portion,
the position for installing the recording disk in the outer cylinder part is determined in accordance with the axial run-out information contained in the information mark.
13. The disk drive device according to claim 12 , wherein the position for installing the recording disk in the outer cylinder part is determined by acquiring the maximum amount of the axial run-out of the outward extension portion of the hub member by referring to the information mark, so as to reduce the amount of the axial run-out.
14. The disk drive device according to claim 12 , wherein the recording disk is installed at the position where the maximum position of the axial run-out of the outward extension portion faces the center of gravity position of the recording disk across the rotation center of the hub member.
15. The subassembly of a disk drive device according to claim 12 , wherein the information mark comprises a barcode including at least two segments encoded with the axial run-out information.