FLUID BEARING DEVICE AND DISK ROTATING DEVICE

摘要

A fluid bearing device, wherein radial bearing surfaces are provided by forming a dynamic pressure generating groove in the inner peripheral surface of a shaft or a sleeve and a clearance between the shaft and the sleeve is filled with a lubricant. To prevent the lubricant in the clearance of a bearing from being shorted by the flow out of the lubricant, for example, when the lubricant in the clearance of the bearing is forced out by air entering in the bearing of the fluid bearing device, an annular recessed part is formed in the end face of the sleeve on the rotor hub side, and a cover plate to cover the recessed part is installed to form a lubricant or air reserving part. A step part is formed in the sleeve on the opposite side of the rotor hub, and the step part is connected to the reserving part through a communication hole. The air in the fluid bearing device is led to the reserving part through the communication hole and exhausted from the reserving part to the outside while the fluid bearing device is being operated.