# US 8,786,981 B2 · Bearing device, method of manufacturing bearing device, and information recording/reproducing apparatus

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- Number: US 8,786,981 B2
- Document ID: US8786981B2
- Status: Granted
- Kind: B2
- Application number: 14/053,649
- Filed: 2013-10-15
- Published: 2014-04-17
- Granted: 2014-07-22
- Earliest claimed: 2012-10-15
- Assignees: Seiko Instruments Inc.
- Applicants: Seiko Instruments Inc.
- Inventors: Akihiro Iino; Akio Ozawa
- Web page: https://patentgrep.com/patent/US8786981B2

## CPC

- G11B 5/54: with provision for moving the head into or out of its operative position or across tracks
- F16C 19/184: {in O-arrangement}
- F16C 33/58: Raceways; Race rings
- F16C 33/581: {integral with other parts, e.g. with housings or machine elements such as shafts or gear wheels}
- F16C 35/063: Fixing them on the shaft (with interposition of an element F16C35/07)
- F16C 43/04: Assembling rolling-contact bearings
- G11B 5/4813: {Mounting or aligning of arm assemblies, e.g. actuator arm supported by bearings, multiple arm assemblies, arm stacks or multiple heads on single arm (G11B5/484 takes precedence)}
- G11B 5/5569: {details of specially adapted mobile parts, e.g. electromechanical control devices (motors in general H02K)}
- F16C 33/416: {made from plastic, e.g. injection moulded comb cages}
- F16C 2226/40: with adhesive
- F16C 2229/00: Setting preload
- F16C 2370/12: Hard disk drives or the like
- Y10T 29/49682: Assembling of race and rolling anti-friction members
- 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)
- F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A first inner ring and a second inner ring respectively include inner ring rolling surfaces formed so that the external radius of inner end portions is smaller than a first separation distance and formed so as to have an external radius that become larger than the first separation distance, and a first outer ring and a second outer ring respectively include outer ring rolling surfaces formed so that the internal radius of outer end portions is larger than a second separation distance and formed so as to have an internal radius that becomes smaller than the second separation distance, and the first outer ring and the second outer ring are formed integrally with each other to form an outer ring.

## Claims

### Claim 1

A bearing device comprising:
a shaft; and
a pair of rolling bearing portions that are arranged side by side in an axial direction of the shaft,
wherein the pair of rolling bearing portions each include an inner ring that is arranged coaxially with a central axis of the shaft; an outer ring that surrounds the inner ring from an outer side of the shaft in a radial direction; and a plurality of rolling elements that are rollably retained between the inner ring and the outer ring,
wherein when a separation distance between an innermost portion of the rolling elements in the radial direction and the central axis is defined as a first separation distance and a separation distance between an outermost portion of the rolling elements in the radial direction and the central axis is defined as a second separation distance, the inner rings of the pair of rolling bearing portions each include an inner ring rolling surface formed so that the external radius of an inner end portion in the axial direction is smaller than the first separation distance and formed so as to have an external radius that becomes larger than the first separation distance from an inner side toward an outer side in the axial direction, and the outer rings of the pair of rolling bearing portions each include an outer ring rolling surface formed so that the internal radius of an outer end portion in the axial direction is larger than the second separation distance and formed so as to have an internal radius that becomes smaller than the second separation distance from the outer side toward inner side in the axial direction, and
wherein the outer rings of the pair of rolling bearing portions are formed integrally with each other.

### Claim 2 (depends on 1)

The bearing device according to claim 1,
wherein the outer end portion of the outer ring in the axial direction is arranged further toward the inner side in the axial direction than an outer end portion of the inner ring in the axial direction.

### Claim 3 (depends on 1)

The bearing device according to claim 1,
wherein a distance from an imaginary plane including the center of the plurality of rolling elements to the inner end portion of the inner ring in the axial direction is formed so as to become shorter than a distance from the imaginary plane to an outer end portion of the inner ring in the axial direction.

### Claim 4 (depends on 1)

The bearing device according to claim 1,
wherein any one inner ring of the inner rings of the pair of rolling bearing portions, and the shaft are formed integrally with each other.

### Claim 5 (depends on 1)

The bearing device according to claim 1,
wherein the inner ring and the outer ring are formed by forging.

### Claim 6 (depends on 1)

The bearing device according to claim 1, further comprising:
a retainer that is arranged between the inner ring and the outer ring and that is capable of rollably retaining and annularly and equally arranging the plurality of rolling elements,
wherein the retainer includes a body portion, and a plurality of claw portion pairs that are erected in the axial direction from the body portion and rollably retain the rolling elements, and
wherein the body portion is arranged further toward the inner side in the axial direction than the rolling elements.

### Claim 7 (depends on 1)

A method of manufacturing the bearing device according to claim 1, comprising:
a first inner ring arranging step of inserting a first inner ring out of the inner rings of the pair of rolling bearing portions into the shaft and arranging the first inner ring on one side in the axial direction;
a retainer retaining step of making each of a first retainer and a second retainer capable of retaining the rolling elements rollably retain and equally and annularly arrange the plurality of rolling elements;
a first rolling element arranging step of inserting the plurality of rolling elements into the first inner ring together with the first retainer from the other side in the axial direction and placing the plurality of rolling elements on the inner ring rolling surface of the first inner ring;
an outer ring arranging step of inserting the outer ring into the first inner ring from the other side in the axial direction;
a second rolling element arranging step of inserting the plurality of rolling elements into the outer ring together with the second retainer from the other side in the axial direction and placing the plurality of rolling elements on the outer ring rolling surface on the other side in the axial direction;
a second inner ring arranging step of inserting a second inner ring out of the inner rings of the pair of rolling bearing portions into the shaft and arranging the second inner ring on the other side in the axial direction; and
a preload applying step of fixing the first inner ring and the second inner ring to the shaft while relatively pressing the first inner ring and the second inner ring in the axial direction.

### Claim 8 (depends on 1)

An information recording/reproducing apparatus comprising:
the bearing device according to claim 1;
a housing that supports one end portion of the bearing device;
a rotating member that is externally fitted to the outer rings and rotates around the central axis of the shaft; and
a slider that is mounted on the rotating member and performs recording and reproducing of information with respect to a magnetic recording medium.