# US 2015/0146366 A1 · System, method and apparatus for disk drive fluid dynamic bearing

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- Number: US 2015/0146366 A1
- Document ID: US20150146366A1
- Status: Published application
- Kind: A1
- Application number: 14/091,189
- Filed: 2013-11-26
- Published: 2015-05-28
- Earliest claimed: 2013-11-26
- Assignees: HGST Netherlands B.V.
- Applicants: Hgst Netherlands B.V.
- Inventors: Toshiki Hirano; Lidu Huang; Chiao-Ping Ku; Gwo-Jeng Lo
- Web page: https://patentgrep.com/patent/US20150146366A1

## CPC

- G11B 5/6005: {Specially adapted for spacing from a rotating disc using a fluid cushion}
- G11B 19/2036: {Motors characterized by fluid-dynamic bearings}
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)

## Abstract

A disk drive can include an enclosure and a media disk rotatably mounted to the enclosure via a spindle. A fluid dynamic bearing (FDB) can be mounted between the enclosure and the spindle of the media disk. The FDB may include an integrally formed shaft and lower thrust bush formed together from a single material.

## Claims

### Claim 1

A disk drive, comprising:
an enclosure;
a media disk rotatably mounted to the enclosure; and
a fluid dynamic bearing (FDB) mounted between the enclosure and the media disk, the FDB comprising an integrally formed shaft and lower thrust bush formed together from a single material, and the single material has a Young's modulus of at least about 2 E8 N/m2.

### Claim at position 2

2-3. (canceled)

### Claim 4 (depends on 1)

The disk drive of claim 1, wherein the media disk comprises a form factor in excess of 2.5 inches to about 15 inches.

### Claim 5 (depends on 1)

The disk drive of claim 1, wherein the media disk comprises a form factor of at least about 3.5 inches to about 15 inches.

### Claim 6 (depends on 1)

The disk drive of claim 1, wherein the enclosure comprises a nest extending therefrom, and the shaft and lower thrust bush are seated in and make contact with the nest on axial and radial sides thereof.

### Claim 7 (depends on 6)

The disk drive of claim 6, wherein axial and radial abutting surfaces of the nest and the shaft and lower thrust bearing are substantially perpendicular and are not conical.

### Claim 8 (depends on 6)

The disk drive of claim 6, wherein the nest has a nest axial dimension that is less than an axial dimension of the shaft, and greater than an axial dimension of the lower thrust bush.

### Claim 9 (depends on 6)

The disk drive of claim 6, wherein the nest has a nest inner radial dimension, the shaft has a shaft outer radial dimension that is less than the nest inner radial dimension, and the lower thrust bush has a bush outer radial dimension that is substantially similar to the nest inner radial diameter.

### Claim 10

(canceled)

### Claim 11 (depends on 1)

The disk drive of claim 1, wherein the shaft and lower thrust bush are not separate parts that are joined together, and they are not formed from different materials.

### Claim 12 (depends on 1)

The disk drive of claim 1, wherein a perpendicularity between the shaft and the lower thrust bush comprises a runout of a few micrometers from the outer diameter to the inner diameter of a thrust plate.

### Claim 13 (depends on 1)

The disk drive of claim 1, wherein the FDB further comprises a top thrust bearing formed from a second material that is softer than the single material.

### Claim 14 (depends on 13)

The disk drive of claim 13, wherein the second material comprises bronze, brass or a combination thereof.

### Claim 15 (depends on 13)

The disk drive of claim 13, wherein the top thrust bearing comprises a top thrust bush ring having either a loose fit or a tight fit on an upper portion of the shaft.

### Claim 16 (depends on 1)

The disk drive of claim 1, wherein the media disk is mounted to a spindle, the spindle is rotatably mounted to the FDB, the enclosure comprises a nest extending therefrom, the shaft and lower thrust bush are seated in and axially and radially abut the nest, and a portion of the spindle extends between the shaft and the nest.

### Claim 17

A disk drive, comprising:
an enclosure having a base with a nest extending therefrom, and a top cover coupled to the base;
a plurality of media disks rotatably mounted to the enclosure, each media disk having a form factor of at least about 3.5 inches; and
a fluid dynamic bearing (FDB) mounted between the enclosure and the plurality of media disks, the FDB comprises an integrally formed shaft and lower thrust bush, the shaft and lower thrust bush are seated in and make contact with the nest, and the FDB comprises a top thrust bearing formed from a material that is softer than the shaft and lower thrust bearing, and the top thrust bearing comprises bronze, brass or a combination thereof.

### Claim 18

(canceled)

### Claim 19 (depends on 17)

The disk drive of claim 17, wherein abutting axial and radial surfaces of the nest and the shaft and lower thrust bearing are substantially perpendicular and are not conical, and the nest has a nest axial dimension that is less than an axial dimension of the shaft, and greater than an axial dimension of the lower thrust bush.

### Claim 20

(canceled)

### Claim 21 (depends on 17)

The disk drive of claim 17, wherein the formed shaft and lower thrust bush consist of a single material having a Young's modulus of at least about 2 E8 N/m2.

### Claim 22 (depends on 17)

The disk drive of claim 17, wherein a perpendicularity between the shaft and the lower thrust bush comprises a runout of a few micrometers from the outer diameter to the inner diameter of a thrust plate.

### Claim 23

(canceled)

### Claim 24

(canceled)

### Claim 25

A disk drive, comprising:
an enclosure having a nest extending therefrom;
a media disk rotatably mounted to the enclosure, the media disk having a form factor of at least about 3.5 inches to about 15 inches;
a fluid dynamic bearing (FDB) mounted between the enclosure and the media disk, the FDB comprising an integrally formed shaft and lower thrust bush formed together from a single material, such that the shaft and lower thrust bush are not separate parts that are joined together, and they are not formed from different materials, and the single material comprises a material having a Young's modulus of at least about 2 E8 N/m2;
the shaft and lower thrust bush are seated in and make contact with the nest on axial and radial sides thereof, and axial and radial abutting surfaces of the nest, shaft and lower thrust bearing are substantially perpendicular;
the FDB further comprises a top thrust bearing formed from a second material that is softer than the single material, and the second material comprises bronze, brass or a combination thereof; and
a perpendicularity between the shaft and the lower thrust bush comprises a runout of a few micrometers from the outer diameter to the inner diameter of a thrust plate.

### Claim at position 25

26-29. (canceled)