Disk drive head suspension assembly with load beam inner rails between piezo actuator elements
View Patent ↗A head suspension assembly for a disk drive includes a load beam, and first and second piezoelectric elements that are disposed within first and second piezoelectric element receiving windows in a mounting plate, respectively. The load beam includes a plurality of rails that includes first and second outer rails and first and second inner rails, each of the plurality of rails being oriented in the longitudinal direction and being formed or bent out of the load beam plane. The first and second inner rails are disposed between the first and second piezoelectric elements, and the first and second outer rails are disposed not between the first and second piezoelectric elements. The first piezoelectric element is disposed between the first outer rail and the first inner rail, and the second piezoelectric element is disposed between the second inner rail and the second outer rail.
1. A disk drive comprising:
a disk drive base;
a spindle attached to the disk drive base;
a disk mounted on the spindle;
a first actuator pivotally attached to the disk drive base, the first actuator including a conductive coil and an actuator arm; and
a head suspension assembly comprising
a mounting plate attached to the actuator arm;
a load beam attached to and extending from the mounting plate in a longitudinal direction, the load beam defining a load beam plane parallel to the mounting plate;
a first piezoelectric element disposed within a first piezoelectric element receiving window in the mounting plate; and
a second piezoelectric element disposed within a second piezoelectric element receiving window in the mounting plate;
wherein the load beam includes a plurality of rails that includes first and second outer rails and first and second inner rails, each of the plurality of rails being oriented in the longitudinal direction and being formed out of the load beam plane by an angle in the range of 45 degrees to 90 degrees relative to the load beam plane;
wherein the first and second inner rails are disposed between the first and second piezoelectric elements, and the first and second outer rails are disposed not between the first and second piezoelectric elements; and
wherein the first piezoelectric element is disposed between the first outer rail and the first inner rail, and the second piezoelectric element is disposed between the second inner rail and the second outer rail; and
a read head supported by the load beam and disposed adjacent a surface of the disk.
2. The disk drive of claim 1 wherein the first outer rail and the first inner rail extend into the first piezoelectric element receiving window in the mounting plate, but not into the second piezoelectric element receiving window in the mounting plate.
3. The disk drive of claim 1 wherein the second inner rail and the second outer rail extend into the second piezoelectric element receiving window in the mounting plate, but not into the first piezoelectric element receiving window in the mounting plate.
4. The disk drive of claim 1 wherein the mounting plate includes an annular raised swage boss.
5. The disk drive of claim 1 wherein the load beam comprises stainless steel sheet metal having a thickness in the range of 20 microns to 103 microns.
6. The disk drive of claim 1 wherein each of the first and second piezoelectric element receiving windows in the mounting plate has an open periphery, so that the mounting plate includes a substantially T-shaped distal portion having a central longitudinally-oriented portion.
7. The disk drive of claim 6 wherein the central longitudinally-oriented portion of the mounting plate is disposed between the first and second inner rails of the load beam.
8. The disk drive of claim 1 wherein the first piezoelectric element is disposed within 150 microns of the first inner rail, and the second piezoelectric element is disposed within 150 microns of the second inner rail.
9. The disk drive of claim 8 wherein the first piezoelectric element is disposed adjacent to the first inner rail, and the second piezoelectric element is disposed adjacent to the second inner rail.
10. The disk drive of claim 1 wherein each of the plurality of rails defines a rail height extending away from the load beam plane, the rail height being at least 0.05 mm.
11. The disk drive of claim 10 wherein each of the first and second piezoelectric elements has a piezoelectric element thickness in the range of 0.1 mm to 0.15 mm, and the rail height is in the range of 0.12 to 0.30 mm.
12. The disk drive of claim 11 wherein each of the first and second piezoelectric elements is bonded to the load beam by an adhesive layer.
13. The disk drive of claim 12 wherein the adhesive layer has an adhesive layer thickness in the range of 0.01 mm to 0.03 mm.
14. The disk drive of claim 10 wherein the first and second piezoelectric elements define a nominal piezoelectric element thickness, and wherein the rail height is greater than the nominal piezoelectric element thickness.
15. A head suspension assembly comprising:
a mounting plate that includes an annular swage boss;
a load beam attached to and extending from the mounting plate in a longitudinal direction, the load beam defining a load beam plane parallel to the mounting plate;
a first piezoelectric element disposed within a first piezoelectric element receiving window in the mounting plate; and
a second piezoelectric element disposed within a second piezoelectric element receiving window in the mounting plate;
wherein the load beam includes a plurality of rails that includes first and second outer rails and first and second inner rails, each of the plurality of rails being oriented in the longitudinal direction and being formed out of the load beam plane by an angle in the range of 45 degrees to 90 degrees relative to the load beam plane;
wherein the first and second inner rails are disposed between the first and second piezoelectric elements, and the first and second outer rails are disposed not between the first and second piezoelectric elements; and
wherein the first piezoelectric element is disposed between the first outer rail and the first inner rail, and the second piezoelectric element is disposed between the second inner rail and the second outer rail.
16. The head suspension assembly of claim 15 wherein the first outer rail and the first inner rail extend into the first piezoelectric element receiving window in the mounting plate, but not into the second piezoelectric element receiving window in the mounting plate.
17. The head suspension assembly of claim 15 wherein the second inner rail and the second outer rail extend into the second piezoelectric element receiving window in the mounting plate, but not into the first piezoelectric element receiving window in the mounting plate.
18. The head suspension assembly of claim 15 wherein each of the first and second piezoelectric element receiving windows in the mounting plate has an open periphery, so that the mounting plate includes a substantially T-shaped distal portion having a central longitudinally-oriented portion.
19. The head suspension assembly of claim 18 wherein the central longitudinally-oriented portion of the mounting plate is disposed between the first and second inner rails of the load beam.
20. The head suspension assembly of claim 15 wherein the first piezoelectric element is disposed within 150 microns of the first inner rail, and the second piezoelectric element is disposed within 150 microns of the second inner rail.
21. The head suspension assembly of claim 20 wherein the first piezoelectric element is disposed adjacent to the first inner rail, and the second piezoelectric element is disposed adjacent to the second inner rail.
22. The head suspension assembly of claim 15 wherein each of the plurality of rails defines a rail height extending away from the load beam plane, the rail height being at least 0.05 mm.
23. The head suspension assembly of claim 22 wherein each of the first and second piezoelectric elements has a piezoelectric element thickness in the range of 0.1 mm to 0.15 mm, and the rail height is in the range of 0.12 to 0.30 mm.
24. The head suspension assembly of claim 22 wherein the first and second piezoelectric elements define a nominal piezoelectric element thickness, and wherein the rail height is greater than the nominal piezoelectric element thickness.