Patent ID: 7940492
Filing Date: 2011-05-10
Classification: F16C,G11B

Abstract:
1. A hydrodynamic bearing device, comprising: a shaft; a sleeve configured to rotate relative to the shaft, the sleeve having an inner peripheral surface opposing an outer peripheral surface of the shaft at a distance in a radial direction so as to form a first gap therebetween; a sealing member provided as one with the sleeve, having an inner peripheral surface opposing an outer peripheral surface of the shaft at a distance in a radial direction so as to form a second gap therebetween, and having an end face opposing one side end face of the sleeve at a distance in an axis direction so as to form a third gap therebetween; a thrust flange provided in close proximity to an end of the shaft, having a diameter larger than that of the shaft, and having an end face opposing the other side end face of the sleeve at a distance in an axis direction so as to form a fourth gap therebetween; at least one connecting channel between the third gap and the fourth gap to connect the third gap and the fourth gap therebetween; and a lubricating fluid retained in at least the first gap, the third gap, the fourth gap, and the connecting channel; a radial dynamic pressure bearing is formed in the first gap, an interface between the lubricating fluid and the atmosphere is formed in the second gap, and a radial clearance A of the first gap, a radial clearance B of the second gap, and an axis direction clearance C of the third gap satisfy a relationship