| 摘要 |
A bearing mechanism includes a shaft portion, a sleeve portion, a lower opposing portion, a lower outer ring-shaped portion, and an upper opposing portion. A lower seal portion serving as a pumping seal portion is provided in a lower seal gap between the sleeve portion and the lower outer ring-shaped portion. An upper seal portion is provided in an upper seal gap joined to an upper thrust gap. The lower portion of the sleeve portion includes a large-diameter portion and a small-diameter portion positioned below the large-diameter portion. The sleeve portion includes a communication path joined to the upper seal gap. The communication path includes an opening portion opened in a border between the large-diameter portion and the small-diameter portion. The outer peripheral portion of the lower opposing portion includes an outer periphery protrusion portion radially opposed to the small-diameter portion and axially opposed to the large-diameter portion. |
