Disk drive arm actuator with piezoelectric ultrasonic motor
A data storage device includes a stack of data storage disks, a head stack assembly, and a piezoelectric motor. The head stack assembly includes an arm, a load beam, a head and a tail. The arm is configured for pivotal motion about a longitudinal axis of an actuator shaft. The load beam is attached to the arm. The head is attached to the load beam and is configured to interact with a surface of one of the disks, the surface defining an x-y plane. The tail is disposed on an opposite side of the actuator shaft from the arm and has a first engagement surface that is parallel to the x-y plane. The piezoelectric motor includes a piezoelectric element and a contact tip. The piezoelectric element comprises a first mounting surface. The contact tip is disposed at the first mounting surface and frictionally contacts the engagement surface.
1 . A data storage device comprising:
a stack of data storage disks mounted on a spindle, the stack comprising a first plurality of disks;
a first head stack assembly comprising:
a first arm configured for pivotal motion about a longitudinal axis of an actuator shaft,
a first load beam attached to the first arm;
a first head attached to the first load beam, wherein the first head is configured to interact with a surface of one of the first plurality of disks, the surface defining an x-y plane; and
a first tail disposed on an opposite side of the actuator shaft from the first arm, the first tail having a first engagement surface that is parallel to the x-y plane; and
a first piezoelectric motor comprising:
a first piezoelectric element comprising a first mounting surface; and
a first contact tip disposed at the first mounting surface, wherein the first contact tip is configured to frictionally contact the first engagement surface to pivot the first head stack assembly about the longitudinal axis.
2 . The data storage device of claim 1 , comprising four electrodes arranged on a respective four quadrants of the first piezoelectric element.
3 . The data storage device of claim 1 comprising a crash stop configured as a vertical column and configured to contact a side surface of the first tail.
4 . The data storage device of claim 3 , wherein the crash stop comprises a lower ring, an upper ring, and a pin having opposed ends inserted into the lower and upper rings.
5 . The data storage device of claim 1 , wherein the first piezoelectric motor comprises a first base comprising a recess, wherein the recess is configured to accommodate a corner of the first piezoelectric element that is opposite the first contact tip.
6 . The data storage device of claim 5 comprising first and second plates:
disposed on opposed first and second sides of the first piezoelectric element; and
attached to the first base.
7 . The data storage device of claim 6 comprising a first plurality of steel springs connecting the first plate to a first perimeter of the first side of the piezoelectric element.
8 . The data storage device of claim 7 comprising a second plurality of steel springs connecting the second plate to a second perimeter of the second side of the piezoelectric element.
9 . The data storage device of claim 5 , wherein the first base comprises first and second opposed end flanges, each of the end flanges comprising a respective first or second aperture.
10 . The data storage device of claim 9 comprising first and second posts to which the first base is attached, via first and second fasteners disposed through the first and second apertures.
11 . The data storage device of claim 1 , comprising:
a second plurality of disks of the stack of data storage disks; and
a second head stack assembly comprising:
a second arm configured for pivotal motion about the longitudinal axis,
a second load beam attached to the second arm;
a second head attached to the second load beam, wherein the second head is configured to interact with a surface of one of the second plurality of disks; and
a second tail disposed on an opposite side of the actuator shaft from the second arm, the second tail having a second engagement surface that is parallel to the x-y plane; and
a second piezoelectric motor disposed next to the first piezoelectric motor, wherein the second piezoelectric motor is configured to frictionally contact the second engagement surface to move the second head stack assembly.
12 . The data storage device of claim 11 , wherein the second piezoelectric motor comprises:
a second piezoelectric element comprising a second mounting surface; and
a second contact tip disposed at the second mounting surface, wherein the second contact tip is configured to frictionally contact the second engagement surface.
13 . The data storage device of claim 12 , wherein a first distance between the first contact tip and the longitudinal axis is longer than a second distance between the second contact tip and the longitudinal axis.
14 . The data storage device of claim 12 , wherein:
the first contact tip is positioned below the first engagement surface; and
the second contact tip is positioned above the second engagement surface.
15 . The data storage device of claim 11 , wherein the second piezoelectric motor comprises a second base, and wherein the second base is longer than the first base.
16 . The data storage device of claim 12 , wherein the second piezoelectric motor comprises a second base, and wherein:
the first base is positioned at a bottom of the first piezoelectric element; and
the second base is positioned at a top of the second piezoelectric element.
17 . The data storage device of claim 11 , wherein the second piezoelectric motor comprises a second base, and wherein:
the first base comprises first and second opposed end flanges, each of the first and second end flanges comprising a respective first or second aperture; and
the second base comprises third and fourth opposed end flanges, each of the third and fourth end flanges comprising a respective third or fourth aperture.
18 . The data storage device of claim 17 comprising:
first and second posts to which the first base is attached, via first and second fasteners disposed through the first and second apertures; and
third and fourth posts to which the second base is attached, via third and fourth fasteners disposed through the third and fourth apertures.
19 . The data storage device of claim 18 , wherein a first distance between the first and second posts is shorter than a second distance between the third and fourth posts.
20 . The data storage device of claim 18 , wherein a first distance between the first post and the longitudinal axis is longer than a second distance between the third post and the longitudinal axis.