THIN STRUCTURE ROTATING DEVICE HAVING IMPROVED IMPACT RESISTANCE

摘要

A rotating device includes: a rotating body, a fixed body and lubricant. A surrounding member in the fixed body has a sleeve and a housing for surrounding the sleeve. A first radial dynamic pressure generating groove and a second radial dynamic pressure generating groove are formed on at least one of the inner circumferential surface of the sleeve and the outer circumferential surface of a shaft in the rotating body. The sleeve has a flange portion protruding radially outward at the end portion of the sleeve near to a hub in the rotating body. A concave portion, which is made by axially concaving at least part of the area corresponding to a wall thickness of the sleeve on the inner circumference side of the flange portion, is circumferentially provided in the flange portion.