Patent ID: 8475048
Filing Date: 2013-07-02
Classification: F16C

Abstract:
1. A dynamic foil gas bearing comprising: a hollow cylindrical member with a rotatable shaft inserted therein; and a foil group mounted on an inner circumferential surface of the hollow cylindrical member, the dynamic foil gas bearing supporting the rotatable shaft in a journal direction; wherein the foil group comprises a sheet-like bump foil, a sheet-like middle foil, and a sheet-like top foil which are arranged successively toward the central axis of the hollow cylindrical member; the middle foil including: a first fixed surface fixed to an inner circumferential surface of the hollow cylindrical member; and a first rotatable shaft holding surface extending along a direction in which the rotatable shaft rotates, the first rotatable shaft holding surface having an end joined to the first fixed surface by a first linkage surface and an opposite end as a free end, the first rotatable shaft holding surface serving to restrain the rotatable shaft circumferentially; the top foil including: a second fixed surface fixed to the inner circumferential surface of the hollow cylindrical member; and a second rotatable shaft holding surface extending along a direction opposite to the direction in which the rotatable shaft rotates, the second rotatable shaft holding surface having an end joined to the second fixed surface by a second linkage surface and an opposite end as a free end, the rotatable shaft holding surface serving to restrain the rotatable shaft circumferentially; wherein the first linkage surface is provided by an angularly bent portion of the middle foil, wherein the middle foil further comprises: the second linkage surface is provided by a curved portion of the top foil, as opposed to the bent shape found in the first linkage surface, wherein: