Patent ID: 8711516

Claim:
A rotating device comprising: a first encircling member which encircles a shaft and which is rotatable relative to the shaft; a shaft supporting member which supports the shaft and which forms an annular first recess where one end of the first encircling member enters together with the shaft; a second encircling member which is provided at another-end side of the first encircling member and which is fixed to the shaft in a manner encircling the shaft; and a lubricant present in respective gaps between the first encircling member and the shaft, the first encircling member and the shaft supporting member, and, the first encircling member and the second encircling member, wherein: the gap between the first encircling member and the shaft includes a radial dynamic pressure generating portion that produces dynamic pressure in the lubricant in a radial direction when the first encircling member rotates relative to the shaft; an annular second recess concaved in an axial direction is formed in an another-end face of the first encircling member; the second encircling member comprises an entering portion that enters the second recess in a non-contact manner; and an outward gap in the radial direction between two gaps where the entering portion and the second recess face with each other in the radial direction includes an air-liquid interface of the lubricant.