Patent ID: 7494282

Claim:
A radial foil bearing comprising: a) a top foil satisfying condition represented by an equation t>0.1·D 0.33 , wherein t is the thickness (mm) and D is the diameter (mm) of a shaft; b) a key welded to a cut portion of the top foil; c) an inner bump foil disposed outwards of the top foil, the inner bump being formed of a wider and higher bump and a narrower and lower bump alternately arranged; d) an outer bump foil disposed outwards of the center of the wider and higher bump of the inner bump foil, the outer bump having a height lower than that of the narrower and lower bump of the inner bump foil; e) a bump sheet for fixing the inner bump and the outer bump; and f) a bearing housing disposed outwards of the bump sheet and having a key groove.