Patent ID: 8553355

Claim:
A motor comprising: a stationary portion including a stator; and a rotating portion including a rotor magnet, and rotatably supported by the stationary portion through a lubricating oil; wherein the stationary portion includes: a shaft portion centered on a central axis extending in a vertical direction; and an upper thrust portion arranged to extend radially outward from an upper portion of the shaft portion; the upper thrust portion includes: a tubular first outer circumferential surface arranged radially outside the upper thrust portion; and a tubular second outer circumferential surface arranged above the first outer circumferential surface; the rotating portion includes: a sleeve portion arranged opposite to an outer circumferential surface of the shaft portion and a lower surface of the upper thrust portion; a tubular portion arranged to extend upward from an outer edge portion of the sleeve portion, and arranged opposite to an outer circumferential surface of the upper thrust portion; and an annular cover portion arranged to extend radially inward from the tubular portion; the lower surface of the upper thrust portion and an upper surface of the sleeve portion are arranged to together define an upper thrust gap therebetween, the lubricating oil is arranged in the upper thrust gap, the outer circumferential surface of the upper thrust portion and an inner circumferential surface of the tubular portion are arranged to together define an upper seal portion therebetween, the upper thrust gap is arranged to be in communication with the upper seal portion, and the upper seal portion includes a surface of the lubricating oil located therein; the annular cover portion includes: a plate portion arranged to extend radially; and an inner annular projecting portion arranged radially inward of the plate portion, and arranged to project upward or downward; an inner circumferential surface of the inner annular projecting portion is arranged above the inner circumferential surface of the tubular portion; the inner circumferential surface of the inner annular projecting portion and the second outer circumferential surface are arranged opposite to each other with an axially extending gap intervening therebetween; and the gap is arranged to have a radial width smaller than a maximum width of the upper seal portion.