Fluid bearing device and disk rotating device

Abstract

The present invention provides 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.

Description

technical field [0001] The present invention relates to a fluid bearing device used for a main shaft of a rotating device requiring high-speed and high-precision rotation, and a magnetic disk rotating device including the same. Background technique [0002] In recent years, in a rotary recording device using a magnetic disk or the like, the memory capacity thereof has increased and the data transfer speed has been increased. For this reason, the magnetic disk rotation device used in this type of recording device needs high-speed and high-precision rotation, and therefore, a fluid bearing device is used for the rotation spindle portion. [0003] Hereinafter, a conventional fluid bearing device will be described with reference to FIGS. 18 and 19 . In FIG. 18 , a shaft 31 is rotatably inserted into a bearing hole 32A of a sleeve 32 mounted on a base 35 . The shaft 31 has a flange 33 formed integrally with the lower end in the figure. The flange 33 is accommodated in the step...

AI Technical Summary

Problems solved by technology

Therefore, there is a fear that the shaft 31 will come into contact with the sleeve 32 during the rotation, and the reliability will be significantly deteriorated.

[0007] In addition, as shown in FIG. 19, even when a drop impact load (acceleration) is applied to the conventional fluid bearing device in the direction shown by G1, there is still a concern that the oil 42 will leak to the outside as shown by the oil 42B.

Images