Disk drive including pivot-bearing cartridge tolerance ring having a damping layer for actuator resonance reduction
View Patent ↗A disk drive includes a pivot-bearing cartridge configured to pivotally support the head stack assembly on the base of the drive. A tolerance ring is coupled to the pivot-bearing cartridge and includes a single sleeve defining an inner sleeve surface facing the pivot-bearing cartridge and an outer sleeve surface facing away therefrom, and a layer of dampening material disposed on the inner or outer sleeve surfaces so as to be in contact with the pivot-bearing cartridge or the bore surface of the through bore that is defined in the body portion of the head stack assembly, respectively.
1. A head stack assembly, comprising:
a body portion, the body portion including a bore surface that defines a through bore;
an actuator arm cantilevered from the body portion;
a read/write head coupled to the actuator arm;
a coil cantilevered from the body portion in an opposite direction from the actuator arm;
a pivot-bearing cartridge configured to fit within the through bore for pivotally supporting the head stack assembly on a base, the pivot-bearing cartridge including an inner portion and an outer portion, the inner and outer portions being separated by upper and lower bearings, the outer portion including an outer surface that faces the bore surface, and
a tolerance ring disposed between the outer surface of the pivot-bearing cartridge and the bore surface, the tolerance ring including:
a single sleeve defining an inner sleeve surface facing the pivot-bearing cartridge and an outer sleeve surface facing away from the pivot-bearing cartridge, and
a layer of dampening material disposed on one of the inner and outer sleeve surfaces so as to encircle the pivot-bearing cartridge over most of its periphery and so as to be in contact with one of the outer surface of the pivot-bearing cartridge and the bore surface, respectively.
2. The head stack assembly of claim 1 , wherein the tolerance ring is configured as a right-cylindrical open ring.
3. A disk drive, comprising:
a base;
a disk;
a spindle motor attached to the base for rotating the disk, and
a head stack assembly pivotally coupled to the base, comprising:
a body portion, the body portion including a bore surface that defines a through bore;
an actuator arm cantilevered from the body portion;
a head for reading from and writing to the disk coupled to the actuator arm, and
a coil cantilevered from the body portion in an opposite direction from the actuator arm;
a pivot-bearing cartridge configured to fit within the through bore for pivotally supporting the head stack assembly on the base, the pivot-bearing cartridge including an inner portion and an outer portion, the inner and outer portions being separated by upper and lower bearings, the outer portion including an outer surface that faces the bore surface, and
a tolerance ring disposed between the outer surface of the pivot-bearing cartridge and the bore surface, the tolerance ring including:
a single sleeve defining an inner sleeve surface facing the pivot-bearing cartridge and an outer sleeve surface facing away from the pivot-bearing cartridge, and
a layer of dampening material disposed on one of the inner and outer sleeve surfaces so as to encircle the pivot-bearing cartridge over most of its periphery and so as to be in contact with one of the outer surface of the pivot-bearing cartridge and the bore surface, respectively.
4. The disk drive of claim 3 , wherein the tolerance ring is configured as a right-cylindrical open ring.