System, method and apparatus for disk drive recirculation filter having inlet and outlet disk rim shrouding
View Patent ↗A hard disk drive has a recirculation filter that shrouds the rims of disks at the inlet and outlet of the filter. The shroud is aerodynamically shaped to reduce flow-induced disk vibration of the read/write head. A significant improvement in non-repeatable run-out is provided when the inlet and outlet are shrouded along the rims of the disks.
1. A hard disk drive, comprising:
a housing;
a disk mounted to the housing and being rotatable relative to the housing, the disk defining an axis of rotation and a radial direction relative to the axis, and the disk having a outer rim, a downstream side wherein air flows away from the disk, and an upstream side wherein air flows toward the disk;
an actuator mounted to the housing and being movable relative to the disk, the actuator having a head for reading data from and writing data to the disk;
a filter channel formed in the housing for directing air flow generated by rotation of the disk through an air filter;
a shroud located between the filter channel and the disk adjacent to both the downstream and upstream sides of the disk, the shroud having arcuate edge walls that are complementary in shape to the outer rim of the disk;
the arcuate edge walls have transverse surfaces that are cylindrical and extend in the axial direction to flatly face the outer rim of the disk, the transverse surfaces being located immediately adjacent to the outer rim of the disk substantially perpendicular to a planar orientation of the disk;
each of the arcuate edge walls has an axial dimension that is equal to or greater than an axial dimension of the disk;
an entire thickness of the disk is axially aligned with or located within the axial dimension of the arcuate edge walls; and
the shroud has arcuate slotted openings that are axially spaced apart from the outer rim of the disk to provide only one ingress and only one egress, respectively, for the filter channel, each of which faces radially inward toward the axis.
2. A hard disk drive according to claim 1 , wherein the shroud is integrally formed with the housing.
3. A hard disk drive according to claim 1 , wherein the shroud directs the air flow generated by rotation of the disk from the downstream side, through the filter channel and the air filter, and to the upstream side of the disk.
4. A hard disk drive according to claim 1 , wherein the shroud is located between an outer perimeter of the housing and the disk at an 11 o'clock position relative to the axis of rotation, and the shroud is located on an opposite side of the disk relative to the actuator.
5. A hard disk drive according to claim 1 , wherein the shroud extends in a circumferential span from about a 9 o'clock position to about a 12 o'clock position relative to the axis of rotation.
6. A hard disk drive according to claim 1 , wherein the arcuate edge walls closely follow an external contour of the outer rim of the disk, the arcuate edge walls being complimentary in shape to the outer rim of the disk.
7. A hard disk drive according to claim 6 , wherein each of the arcuate edge walls is radially spaced apart from the outer rim by a radial clearance that is greater than 0 mm but less than 1 mm.
8. A hard disk drive according to claim 1 , wherein ingress is provided through a downstream one of the arcuate slotted openings that is formed on the downstream side of the disk, and egress if provided through an upstream one of the arcuate slotted openings that is formed on the upstream side of the disk.
9. A hard disk drive according to claim 8 , wherein the arcuate slotted openings are divided by a partition that is located at an 11 o'clock position relative to the axis of rotation.
10. A hard disk drive according to claim 1 , wherein the air filter is located only adjacent to the upstream side of the disk.
11. A hard disk drive, comprising:
a housing;
a disk mounted to the housing and being rotatable relative to the housing, the disk defining an axis of rotation and a radial direction relative to the axis, and the disk having an outer rim, a downstream side wherein air flows away from the disk, and an upstream side wherein air flows toward the disk;
an actuator mounted to the housing and being movable relative to the disk, the actuator having a head for reading data from and writing data to the disk;
a filter channel formed in the housing for directing air flow generated by rotation of the disk through an air filter; and
a shroud located between the filter channel and the disk adjacent to both the downstream and upstream sides of the disk, the shroud having arcuate edge walls that are complementary in shape to the outer rim of the disk, the arcuate edge walls closely follow an external contour of the outer rim of the disk, the arcuate edge walls being complimentary in shape to the outer rim of the disk and having generally cylindrical transverse surfaces extending in the axial direction that flatly face the outer rim of the disk, the transverse surfaces being located immediately adjacent to the outer rim of the disk substantially perpendicular to a planar orientation of the disk, and the shroud has arcuate slotted openings formed adjacent to the arcuate edge walls but axially spaced apart from the outer rim of the disk to provide ingress and egress for the filter channel exclusively in a radial direction relative to the axis.
12. A hard disk drive according to claim 11 , wherein the shroud is integrally formed with the housing.
13. A hard disk drive according to claim 11 , wherein the shroud directs the air flow generated by rotation of the disk from the downstream side, through the filter channel and the air filter, and to the upstream side of the disk.
14. A hard disk drive according to claim 11 , wherein the shroud is located between an outer perimeter of the housing and the disk at an 11 o'clock position relative to the axis of rotation, and the shroud is located on an opposite side of the disk relative to the actuator.
15. A hard disk drive according to claim 11 , wherein the shroud extends in an arcuate span from about a 9 o'clock position to about a 12 o'clock position relative to the axis of rotation.
16. A hard disk drive according to claim 11 , wherein the arcuate edge walls are radially spaced apart from the outer rim by a radial clearance of no more than about 0.2 mm.
17. A hard disk drive according to claim 11 , wherein each of the arcuate edge walls has an axial dimension that is equal to or greater than an axial dimension of the disk, and wherein an entire thickness of the disk is axially aligned with or located within the axial dimension of the edge wall in an axial direction.
18. A hard disk drive according to claim 11 , wherein ingress is provided through a downstream one of the arcuate slotted openings that is located on the downstream side of the disk, and egress if provided through an upstream one of the arcuate slotted openings that is located on the upstream side of the disk.
19. A hard disk drive according to claim 11 , wherein the arcuate slotted openings are divided by a partition that is located at an 11 o'clock position relative to the axis of rotation.
20. A hard disk drive according to claim 11 , wherein the air filter is located only adjacent to the upstream side of the disk.