Hydraulic bearing, main shaft motor with said hydraulic bearing and disc driver with said main shaft motor

Abstract

The present invention relates to a hydraulic bearing that supports a shaft and a sleeve for relative rotation with respect to a rotating shaft. In one example of the hydraulic bearing of the present invention, the capillary seal portion is formed continuously with the bearing portion that uses lubricating oil as the working fluid and is held by a minute gap. The capillary seal portion includes: a first capillary seal portion whose radial gap becomes at least larger as it moves away from the bearing portion toward the rotation axis; The second capillary seal portion has at least a larger radial gap away from the second capillary seal portion in the direction toward the rotation axis. The second capillary seal portion gradually expands toward the outer side in the axial direction.

Description

technical field [0001] The present invention relates to a hydrodynamic bearing (Hydrodynamic Bearing), a spindle motor using the bearing, and a disk drive device having the spindle motor. Background technique [0002] As a bearing for freely rotating a rotor (rotor) of a spindle motor used in a disk drive device such as a hard disk drive, fluid dynamic bearings capable of achieving quiet, low-vibration, and stable rotation have begun to be used. [0003] As such a fluid dynamic bearing, there is, for example, US Pat. No. 5,423,612. Figure 4 A partially enlarged cross-sectional view showing a partial schematic structure of the aforementioned US Patent No. 5,423,612. [0004] The thrust plate 102 is fixed on the fixed shaft 100, and is held between the outer peripheral surface of the fixed shaft 100 located below the axial direction of the thrust plate 102 and the inner peripheral surface of the rotor 104 opposite to the outer peripheral surface in the radial direction as a w...

AI Technical Summary

Problems solved by technology

Although this structure of the capillary seal part makes the volume of the capillary seal part the same as Figure 4 Compared with the structure, it can be enlarged, but the capillary seal is still affected by the change of the gap dimension due to the axial vibration of the rotor, so the resistance to the external vibration boosting force when the rotor stops rotating is insufficient.

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