# US 11,306,771 B2 · Radial foil bearing

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- Number: US 11,306,771 B2
- Document ID: US11306771B2
- Status: Granted
- Kind: B2
- Application number: 16/493,119
- Filed: 2018-03-14
- Published: 2020-04-23
- Granted: 2022-04-19
- Earliest claimed: 2017-03-15
- Assignees: IHI Corporation
- Applicants: Ihi Corporation
- Inventors: Naomichi Omori
- Web page: https://patentgrep.com/patent/US11306771B2

## CPC

- F16C 17/024: {with flexible leaves to create hydrodynamic wedge, e.g. radial foil bearings}
- F16C 27/02: Sliding-contact bearings
- F16C 43/02: Assembling sliding-contact bearings
- F16C 2226/76: with tongue and groove or key and slot
- F16C 2240/60: Thickness, e.g. thickness of coatings
- F16C 2300/22: High-speed rotation
- F16C 2360/00: Engines or pumps
- F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS

## Abstract

The radial foil bearing (3, 3A, 3B, 3D) includes: a wave sheet-shaped back foil (11); and an intermediate foil (10) supported by the back foil, and the intermediate foil includes a flat portion (10b) facing a hill part (11c) of a wave sheet shape of the back foil, and a protruding part (39, 40, 40a, 40b, 40B) protruding toward the back foil via branching at a position in a circumferential direction between a top of at least one hill part and a top of a hill part adjacent to the one hill part in the wave sheet shape of the back foil.

## Claims

### Claim 1

A radial foil bearing, comprising:
a wave sheet-shaped back foil; and
an intermediate foil supported by the back foil,
wherein
the intermediate foil includes
a flat portion facing a hill part of the wave sheet-shaped back foil, and
a protruding part protruding toward the back foil via branching at a position in a circumferential direction between a top of at least one hill part and a top of another hill part adjacent to the one hill part in the wave sheet-shaped back foil, and
the protruding part is partially surrounded by a slit formed in the intermediate foil and is pushed out to protrude radially outward.

### Claim 2 (depends on 1)

The radial foil bearing according to claim 1, wherein
the flat portion of the intermediate foil is provided with a first branching position at a position in the circumferential direction between the top of the one hill part and the top of the other hill part adjacent to the one hill part in the wave sheet-shaped back foil,
the protruding part includes a first branching part extending from the first branching position, and
the first branching part is partially surrounded by the slit formed in the intermediate foil and is pushed out to protrude radially outward.

### Claim 3 (depends on 2)

The radial foil bearing according to claim 2, wherein
the flat portion of the intermediate foil is provided with a second branching position, different from the first branching position, at a position in the circumferential direction between the top of the one hill part and the top of the other hill part adjacent to the one hill part in the wave sheet-shaped back foil,
the protruding part includes a second branching part extending from the second branching position, and
the second branching part is partially surrounded by the slit formed in the intermediate foil and is pushed out to protrude radially outward.

### Claim 4 (depends on 2)

The radial foil bearing according to claim 2, wherein
the first branching part includes
a separating part separating radially outward from the flat portion, and
an approaching part extending from the separating part and approaching radially inward toward the flat portion.

### Claim 5 (depends on 1)

The radial foil bearing according to claim 1, wherein
the flat portion of the intermediate foil is provided with a pair of branching positions, a first branching position of the pair of branching positions being at a position in the circumferential direction between the top of the one hill part and the top of the other hill part on one of two sides of the one hill part, and a second branching position of the pair of branching positions being at a position in the circumferential direction between the top of the one hill part and a top of further another hill part adjacent to the one hill part on the other of the two sides of the one hill part, in the wave sheet-shaped back foil,
the protruding part includes a pair of branching parts extending from the pair of branching positions, and
each of the pair of branching parts is partially surrounded by the slit formed in the intermediate foil and is pushed out to protrude radially outward.