Patent ID: 8144423
Filing Date: 2012-03-27
Classification: F16C,G11B

Abstract:
1. A fluid dynamic pressure bearing device comprising: a rotating member including a through-hole substantially coaxial with a central axis; a shaft located in the through-hole of the rotating member, the shaft including an outer circumferential surface; an annular member arranged to extend radially outwards away from the outer circumferential surface of the shaft, the annular member being arranged in an opposing relationship with the rotating member, the annular member including an outer circumferential surface; and a seal member including an inner circumferential surface radially opposed to the annular member and an axial end surface portion axially opposed to the rotating member; wherein a first gap is arranged between the inner circumferential surface of the seal member and a radially outermost surface of the annular member; a second gap communicating with the first gap is arranged between the axial end surface portion of the seal member and the rotating member; a third gap communicating with the second gap is arranged axially between the annular member and the rotating member; a lubricating fluid is continuously arranged in the first gap, the second gap, and the third gap; and a width of the first gap between the inner circumferential surface of the seal member and a radial outermost portion of the outer circumferential surface of the annular member is smaller than a width of the second gap between a radial inner end of the axial end surface portion of the seal member and the rotating member but greater than a width of the third gap.