Disk drive with multi-zone arm damper
View Patent ↗Described herein is a disk drive having a head stack assembly with an actuator arm that is rotatable about an axis of rotation and has a damping layer disposed on the actuator arm. The damping layer has first and second damping portions, which can include an adhesive or viscoelastic layer. The first damping portion has different damping properties than the second damping portion.
1. A disk drive comprising:
a disk having a recording surface;
an actuator rotatable about an axis of rotation, the actuator comprising an actuator arm extending from the axis of rotation and configured to rotate over the disk recording surface; and
an adhesive layer disposed on the actuator arm, the adhesive layer comprising first and second damping portions, wherein the first damping portion comprises first temperature-dependent damping properties, and the second damping portion comprises second temperature-dependent damping properties, different from the first temperature-dependent damping properties.
2. The disk drive of claim 1 , wherein the first damping portion has a higher optimal operating temperature range than the second damping portion.
3. The disk drive of claim 2 , wherein the first damping portion is disposed on the actuator arm adjacent the axis of rotation.
4. The disk drive of claim 2 , wherein the first damping portion is disposed on the actuator arm closer to the axis of rotation than the second damping portion.
5. The disk drive of claim 1 , wherein the first damping portion has an optimal operating temperature range between about 0° C. and about 70° C.
6. The disk drive of claim 5 , wherein the second damping portion has an optimal operating temperature range between about 40° C. and about 70° C.
7. The disk drive of claim 1 , wherein the first damping portion provides different damping effects than the second damping portion.
8. The disk drive of claim 1 , wherein the adhesive layer extends along a top surface of the actuator arm.
9. The disk drive of claim 1 , wherein the first damping portion comprises a visco-elastic material.
10. The disk drive of claim 1 , wherein the first and second damping portions are separated by a long axis of the actuator arm.
11. The disk drive of claim 1 , further comprising a third damping portion having damping properties different than the first and second damping portions.
12. The disk drive of claim 11 , wherein the third damping portion is separated from at least one of the first and second damping portions by at least one of a long axis of the actuator arm or a short axis of the actuator arm.
13. A head stack assembly for a disk drive, the head stack assembly comprising:
an actuator arm configured to be rotatable about an axis of rotation; and
an adhesive layer disposed on the actuator arm, the adhesive layer comprising first and second damping portions, wherein the first damping portion comprises different material-dependent damping properties than the second damping portion, and wherein the first damping portion is positioned at a different radial distance from the axis of rotation than the second damping portion.
14. The head stack assembly of claim 13 , wherein the first damping portion has a higher optimal operating temperature range than the second damping portion.
15. The disk drive of claim 14 , wherein the first damping portion is disposed on the actuator arm closer to the axis of rotation than the second damping portion.
16. The disk drive of claim 13 , wherein the first damping portion has an optimal operating temperature range between about 0° C. and about 70° C.
17. The disk drive of claim 16 , wherein the second damping portion has an optimal operating temperature range between about 40° C. and about 70° C.
18. The disk drive of claim 13 , wherein the first damping portion provides different damping effects than the second damping portion.
19. The disk drive of claim 13 , wherein the different material-dependent damping properties of the first damping portion and the second damping portion are temperature-dependent damping properties.
20. The disk drive of claim 13 , wherein the adhesive layer extends along a top surface of the actuator arm.
21. The disk drive of claim 13 , wherein the first damping portion comprises a visco-elastic material.
22. The disk drive of claim 13 , further comprising a third damping portion with material-dependent damping properties different than the first and second damping portions.
23. The disk drive of claim 22 , wherein the third damping portion is separated by at least one of the first and second damping portions by a long axis of the actuator arm.
24. A method for damping actuator arm vibrations of a disk drive, the method comprising:
providing a head stack assembly having an actuator arm rotatable about an axis of rotation; and
disposing on the actuator arm an adhesive layer comprising first and second damping portions, wherein the first damping portion comprises different material-dependent damping properties than the second damping portion, and wherein the first damping portion is disposed closer to the axis of rotation than the second damping portion.
25. The method of claim 24 , wherein the disposing comprises disposing a damping portion having a lower optimal damping temperature range farther from the axis of rotation than a damping portion having a higher optimal damping temperature range.