Disk drive device having function of discharging static electricity
A bearing unit includes a shaft and a hub as a conductive rotating body that supports a recording disk. Also, the bearing unit includes a conductive resin housing configured to surround at least part of the shaft to support the shaft and to be able to conduct electricity to the recording disk via the shaft. The conductive resin housing includes a conductive adhesive to be applied to secure conduction with the base housing. The conductive resin housing has an exposed portion where the inner layer of the conductive resin housing is exposed, at a position to which the conductive adhesive is applied.
1. A disk drive device comprising:
a base housing configured to have conductivity in at least part thereof, said base housing having an inner wall surface;
a bearing unit configured to be arranged inside the base housing and to rotatably support a recording disk relative to the base housing; and
a drive unit configured to rotationally drive the recording disk supported by the bearing unit,
wherein the bearing unit includes:
a conductive rotating body configured to support the recording disk;
a conductive resin housing configured to surround at least part of the rotating body to support the rotating body and to be able to conduct electricity to the recording disk via the rotating body, said conductive resin housing being fixed to said inner wall surface of said base housing by a non-conductive adhesive; and
a conductive adhesive applied between the conductive resin housing and the base housing to secure conduction between the conductive resin housing and the base housing,
wherein the conductive resin housing has an exposed portion adjacent to said base housing and not covered by said non-conductive adhesive but covered by the conductive adhesive, and wherein the exposed portion is coated with the conductive adhesive to secure conduction between the conductive resin housing and the base housing.
2. The disk drive device according to claim 1 , wherein static electricity charged in the recording disk is smoothly discharged to the base housing via the exposed portion and the conductive adhesive.
3. The disk drive device according to claim 1 , wherein the conductive resin housing is mixed with conductive filler.
4. The disk drive device according to claim 3 , wherein the conductive filler is exposed to the surface of the exposed portion.
5. The disk drive device according to claim 4 , wherein the conductive adhesive is in direct contact with the conductive filler.
6. The disk drive device according to claim 1 , wherein the conductive resin housing contains carbon.
7. The disk drive device according to claim 1 , wherein the conductive resin housing contains polyetherimide.
8. The disk drive device according to claim 1 , wherein the exposed portion is configured as an area corresponding to a position of a gate remnant that remains at an area from which a resin is injected in molding the conductive resin housing.
9. The disk drive device according to claim 8 , wherein the gate remnant is formed in a concave portion formed on the end surface of the conductive resin housing.
10. The disk drive device according to claim 1 , wherein the exposed portion is formed near the inner wall of the base housing.
11. The disk drive device according to claim 1 , wherein the conductive adhesive covers the whole exposed portion.
12. A disk drive device comprising:
a base housing configured to have conductivity in at least part thereof;
a bearing unit arranged inside the base housing and configured to rotatably support a recording disk relative to the base housing; and
a drive unit configured to rotationally drive the recording disk supported by the bearing unit, wherein the bearing unit includes:
a rotating body configured to support the recording disk;
a conductive housing configured to surround at least part of the rotating body to support the rotating body and configured to conduct electricity to the recording disk via the rotating body;
the conductive housing fixed inside the base housing by a non-conductive adhesive; and
a conductive adhesive applied between the conductive housing and the base housing to secure conduction therebetween, and
wherein one of the base housing and the conductive housing has, on an end surface thereof intersecting with a facing surface thereof facing that of the other of the base housing and the conductive housing, at least two stages of adhesive-reception grooves.
13. The disk drive device according to claim 1 , wherein
one of the base housing and the conductive resin housing has, on an end surface thereof intersecting with a facing surface thereof facing that of the other of the base housing and the conductive resin housing, at least two stages of adhesive-reception grooves.
14. The disk drive device according to claim 12 , wherein static electricity charged in the recording disk is smoothly discharged to the base housing via the conductive adhesive.
15. The disk drive device according to claim 12 , wherein the conductive housing is mixed with conductive filler.
16. The disk drive device according to claim 15 , wherein the conductive adhesive is in direct contact with the conductive filler.
17. The disk drive device according to claim 12 , wherein the conductive housing contains carbon.
18. The disk drive device according to claim 12 , wherein the conductive housing contains polyetherimide.