Dynamic magnetic information storage or retrieval – Record transport with head stationary during transducing – Disk record
Reexamination Certificate
2002-03-29
2004-03-02
Cao, Allen (Department: 2652)
Dynamic magnetic information storage or retrieval
Record transport with head stationary during transducing
Disk record
Reexamination Certificate
active
06700736
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This application relates to a disk drive. More particularly, this application relates to an airflow spoiler that disrupts the formation of a laminar core airflow pattern between two co-rotating disks.
2. Description of the Related Art
A disk drive includes at least one disk with a magnetic medium deposited thereon between an inner circumference and an outer circumference. The disk is mounted on and rotated by a spindle motor assembly. The disk drive also includes a data transfer head that writes data onto the magnetic medium and that reads data from the magnetic medium in concentric, generally circular tracks. In most applications, the data transfer head is extended out over the magnetic medium by an actuator assembly that moves the head in an arcuate path with respect to the magnetic medium. The actuator assembly usually includes an actuator arm and a head-gimbal assembly (HGA) that includes the data transfer head. The tracks on the disk are divided into sectors, which are presented to the data transfer head by the rotation of the disk.
Generally, the data transfer head is positioned over a selected track by a servo-system that includes servo data written onto the tracks. The servo information can be read by the data transfer head to provide an indication of how close the head is to the centerline of a track. When the head is over the centerline of the track and follows it, the head is said to be track-following. When the head wanders from the centerline of the track, there is said to be track misregistration, or “TMR.”
One factor that influences the TMR that the disk drive will experience is the airflow patterns that are generated by the rotation of the disk. As is known, a moving surface, such as the rotating disk, will cause a surrounding fluid, such as air, to move. The movement of this air near the surface of the disk can take different forms depending on the location of other structures near the rotating disk (e.g., another disk), the rotational speed of the disk, the proximity of a boundary (e.g., the outer edge of the disk), and other factors. In general, a laminar airflow pattern is induced under some conditions between two disks that are adjacent, i.e., co-rotating disks. This pattern generally extends to a location between the inner circumference of the disks and the outer circumference of the disks. Variability in the size and location of the laminar airflow pattern induces variable vibrations in the actuator arms. These variable vibrations propagate into the head-gimbal assembly and cause the data transfer head to move with respect to the track below the head, and thus increase the TMR experienced by the disk drive. Increased TMR is not desirable because increased TMR limits track-to-track spacing (i.e., track pitch) and consequently limits areal density.
SUMMARY OF THE INVENTION
An object of this invention is to provide an airflow spoiler that disrupts the laminar inner core to reduce the TMR experienced by a disk drive.
In one embodiment, the present invention comprises a disk drive that includes an enclosure, a spindle motor assembly mounted on the enclosure, and at least two disks. The spindle motor assembly includes a hub that is rotatable with respect to the enclosure. The at least two disks are mounted on the hub. Each of the disks has an inner circumference, an outer circumference, and a magnetic medium deposited between the inner circumference and the outer circumference. The disks define a volume therebetween wherein airflow is generated when the disks rotate. The disk drive also includes an actuator assembly and an airflow spoiler positioned between the at least two disks. The airflow spoiler has a spoiler mounting portion and a non-data bearing extending portion. The spoiler mounting portion is configured to be mounted on the hub of the spindle motor assembly. The non-data bearing extending portion is connected to the spoiler mounting portion and extends outwardly therefrom into the volume defined between the disks. The non-data bearing extending portion extends at least partially over the magnetic medium.
In another embodiment, the present invention comprises a disk drive that includes an enclosure and a spindle motor assembly mounted on the enclosure. The spindle motor assembly includes a hub that is rotatable with respect to the enclosure. The disk drive also includes an actuator assembly that has a first actuator arm with a first head-gimbal assembly mounted thereon and a second actuator arm with a second head-gimbal assembly mounted thereon. The disk drive also includes a first disk mounted on the hub and a second disk mounted on the hub. The first disk and the second disk define a volume therebetween wherein airflow is generated when the first disk and the second disk rotate. The disk drive also has an airflow spoiler positioned between the first disk and the second disk. The airflow spoiler comprises a spoiler mounting portion configured to be mounted on the hub of the spindle motor assembly and also comprises an extending portion. The extending portion extends outwardly from the spoiler mounting portion into the volume defined between the first disk and the second disk. The extending portion is positioned on the spoiler mounting portion so as to create a first clearance between the extending portion and the first disk and to create a second clearance between the extending portion and the second disk. The first clearance is large enough to receive a portion of the first head-gimbal assembly when the actuator assembly moves the portion of the first head-gimbal assembly into the first clearance. The second clearance is large enough to receive a portion of the second head-gimbal assembly when the actuator assembly moves the portion of second head-gimbal assembly into the second clearance.
In another embodiment, the present invention comprises an airflow spoiler for a disk drive. The disk drive has an enclosure, a spindle motor assembly mounted on the enclosure, and at least two disks. The spindle motor assembly includes a hub. The at least two disks are mounted on the hub. Each of the disks has an inner circumference, an outer circumference, and a magnetic medium deposited between the inner circumference and the outer circumference. The disks define a volume therebetween wherein airflow is generated when the disks rotate. The airflow spoiler includes a spoiler mounting portion and a non-data bearing extending portion. The spoiler mounting portion is configured to be mounted on the hub of the spindle motor assembly. The non-data bearing extending portion is connected to the spoiler mounting portion and extends outwardly therefrom into the volume defined between the disks. The non-data bearing extending portion is configured to extend at least partially over the magnetic medium when the airflow spoiler is positioned in the disk drive.
In another embodiment, the present invention comprises an airflow spoiler for a disk drive. The disk drive has an enclosure and a spindle motor assembly mounted on the enclosure. The spindle motor assembly includes a hub. The disk drive also includes a first disk mounted on the hub and a second disk mounted on the hub. The first disk and the second disk define a volume therebetween wherein airflow is generated when the first disk and the second disk rotate. The disk drive also includes an actuator assembly that has a first actuator arm and a second actuator arm. The first actuator arm has a first head-gimbal assembly mounted thereon, and the second actuator arm has a second head-gimbal assembly mounted thereon. The airflow spoiler includes a spoiler mounting portion and an extending portion. The spoiler mounting portion is configured to be mounted on the hub of the spindle motor assembly. The extending portion extends outwardly from the spoiler mounting portion into the volume defined between the first disk and the second disk. The extending portion is positioned on the spoiler mounting portion so that when the airflow spoiler is positioned in the disk drive, a fir
Ou-Yang Jin Hui
Wu Hsueh-Chieh
Yang Lin
Cao Allen
Knobbe Martens Olson & Bear LLP
Shara, Esq. Milad G.
Western Digital Technologies Inc.
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