Patent ID: 8824096

Claim:
A motor comprising: a stationary portion; and a rotating portion arranged to rotate about a central axis relative to the stationary portion; wherein the rotating portion includes: a disk-shaped or substantially disk-shaped hub body portion; and a shaft arranged to extend in an axial direction; the hub body portion includes: a hub through hole arranged to pass through the hub body portion and to have the shaft fixed therein; and a hub recessed portion arranged to extend radially outward from an outside surface of the shaft to define an annular or substantially annular shape and to be recessed axially downward; the hub recessed portion includes: a first ridge portion being an axially upper edge of an inside surface defining the hub through hole; an annular or substantially annular second ridge portion arranged radially outward of the first ridge portion; an annular or substantially annular third ridge portion arranged radially outward of the second ridge portion, and located axially above both the first ridge portion and the second ridge portion; and an adhesive arranged to cover a boundary between the first ridge portion and the outside surface of the shaft throughout an entire circumferential extent thereof; wherein the adhesive is arranged to cover the outside surface of the shaft and reach at least a portion of the second ridge portion.