Foil bearing

• US 20040042692A1
• Filed: 08/21/2003
• Published: 03/04/2004
• Est. Priority Date: 08/28/2002
• Status: Active Grant

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Matsunaga, Minoru
• Granted Patent: US 6,921,207 B2
• Time in Patent Office: Days
• US Class Current: 384/103
• CPC Class Codes: F16C 17/024 with flexible leaves to create hydrodynamic wedge, e.g. radial foil bearings
• CPC Class Codes: F16C 17/042 with flexible leaves to create hydrodynamic wedge, e.g. axial foil bearings
• CPC Class Codes: F16C 2360/23 Gas turbine engines in general F02C

Abstract

In a foil bearing (23) having a plurality of foils (26) disposed in a gap between a rotating member (12) and a stationary mount member (25), a circumferentially extending portion of each foil and a moveable member (27) rotatable with respect to the stationary mount member are provided with magnets (30, 31) so that a magnetic force between these magnets urges the foils toward the rotating member. By rotating the moveable member to vary the relative circumferential position of the moveable member with respect to the foils, it is possible to adjust an amount of magnetic force between the magnets of the moveable member and the magnets of the foils.

Claims

1. A foil bearing for supporting a rotating member that rotates about an axis, comprising:

a stationary mount member spaced from the rotating member so that a gap is defined between the stationary mount member and the rotating member;

a moveable member rotatable about the axis; and

a first foil disposed in the gap between the rotating member and the stationary mount member to support the rotating member via a fluid film when the rotating member rotates,

wherein the first foil comprises a substantially circumferentially extending portion to which a first magnet is provided;

wherein the moveable member is provided with a second magnet so that a magnetic force between the first magnet and the second magnet can urge the first foil toward the rotating member; and

wherein an amplitude of the magnetic force can be by rotating the moveable member around the axis to vary a relative circumferential position between the first magnet and the second magnet.

2. A foil bearing according to claim 1, comprising a plurality of the first foils arranged in a circumferential direction of the rotating member, and at least one of the plurality of first foils is provided with the first magnet.

3. A foil bearing according to claim 2, wherein each of the first foils is provided with the first magnet.

4. A foil bearing according to claim 3, wherein the moveable member is provided with a plurality of the second magnets which have varying magnetic strengths.

5. A foil bearing according to claim 3, wherein the first magnets provided to the plurality of first foils have varying magnetic strengths.

6. A foil bearing according to claim 2, wherein spaces between adjacent ones of the plurality of first foils are varied.

7. A foil bearing according to claim 1, wherein the rotating member comprises a shaft having a substantially cylindrical portion, and the stationary mount member surrounds the shaft so that the gap is formed as an annular gap defined between a cylindrical surface of the cylindrical portion of the shaft and the stationary mount member.

8. A foil bearing according to claim 7, wherein the shaft consists of a rotor shaft of a gas turbine engine, and the foil bearing constitutes a journal bearing for the rotor shaft of the gas turbine engine.

9. A foil bearing according to claim 7, comprising a plurality of the first foils arranged in a circumferential direction of the shaft, and the foil bearing further comprises a second foil disposed between the shaft and the plurality of first foils and extending in the circumferential direction to have a substantially cylindrical shape.

10. A foil bearing according to claim 7, wherein the first foil consists of a single member extending in a circumferential direction to have a substantially cylindrical shape.

11. A foil bearing according to claim 1, wherein the rotating member comprises a disk-shaped member and the gap is defined between the stationary mount member and a planar surface of the disk-shaped member.

12. A foil bearing according to claim 11, wherein the disk-shaped member is provided as a unitary portion of a rotor shaft of a gas turbine engine, and the foil bearing constitutes a thrust bearing of the rotor shaft of the gas turbine engine.