| Patent application number | Description | Published |
|---|
| 20100195248 | DISK DRIVE DEVICE PROVIDED WITH FLUID DYNAMIC BEARING - A sleeve supports a shaft. A housing member is arranged so as to surround the sleeve and make the end of the sleeve protrude. A base member holds the housing member and fixes a stator core so as to surround the housing member. A hub drives a recording disk by being rotated integrally with the shaft, with a magnet being fixed to an annular portion concentric with the shaft so as to face the stator core fixed to the base member. A thrust member is rotated integrally with the hub, and a descender portion and a ring portion. | 08-05-2010 |
| 20100239194 | DISK DRIVE DEVICE IMPROVED IN HANDLING PROPERTY - A disk drive device includes a base member, a hub member, a shaft, a flange, a sleeve, a thrust dynamic pressure generation portion including thrust dynamic pressure grooves such that thrust dynamic pressure is generated in a thrust space, a radial dynamic pressure generation portion including radial dynamic pressure grooves such that radial dynamic pressure is generated in a radial space, a lubricant filled in the thrust space in the thrust dynamic pressure generation portion and the radial space in the radial dynamic pressure generation portion, a capillary seal portion for holding the lubricant in the thrust space and the radial space, and a circulation pathway by which the thrust dynamic pressure generation portion and the radial dynamic pressure generation portion communicate with each other in order to circulate the lubricant. At least one of the areas among where the thrust dynamic pressure groove is formed and where the radial dynamic pressure groove is formed is made of an impact absorption body with a coefficient of elasticity less than or equal to 20 GPa. | 09-23-2010 |
| 20110033143 | DISK DRIVE DEVICE IMPROVED IN ANTI-VIBRATION CHARACTERISTIC - A disk drive device includes a rotating body, a fluid dynamic bearing unit that rotatably supports the rotating body, and a drive unit. The fluid dynamic bearing unit has: a lubricant holding portion in which lubricant is held; a first thrust dynamic pressure groove with which a first thrust dynamic pressure generating portion for generating the dynamic pressure in the pump-in direction, which is oriented toward the inside of the lubricant holding portion, is structured; and a second thrust dynamic pressure groove with which a second thrust dynamic pressure generating portion for generating at least the dynamic pressure in the pump-out direction, is structured. The first thrust dynamic pressure generating portion and the second thrust dynamic pressure generating portion have dynamic pressure generation characteristics in which, when the rotating body is biased in the rotational axis direction from the state where the rotating body is floating in the lubricant, the sum of the changes in the dynamic pressure in the pump-out direction is larger than that of the changes in the dynamic pressure in the pump-in direction. | 02-10-2011 |
| 20110033144 | DISK DRIVE DEVICE - In a disk drive device according to an embodiment, radial dynamic pressure corresponding portions are structured such that the diameters thereof expand toward the axial outside of the sleeve, and that the shaft is in surface-contact with each of the radial dynamic pressure corresponding portions when the rotational drive of the disk drive device is stopped. Further, a herringborn-shaped radial dynamic pressure groove is formed in each of the radial dynamic pressure corresponding portions. The radial dynamic pressure groove in each radial dynamic pressure corresponding portion is formed such that the axial outside length from the turned-back portion of the herringborn-shape is longer than the axial inside length therefrom. | 02-10-2011 |
| 20110064341 | DISK DRIVE DEVICE CAPABLE OF BEING IMPROVED IN ANTI-VIBRATION CHARACTERISTIC - A disk drive device includes: a hub on which a recording disk is to be mounted; a shaft; a sleeve configured to house the shaft and to be rotatable relatively with respect to the shaft; a radial space portion formed between the inner circumferential surface of the sleeve and the outer circumferential surface of the shaft; a radial dynamic pressure generating portion configured to generate radial dynamic pressure between at least part of the inner circumferential surface of the sleeve and the outer circumferential surface of the shaft in the radial space portion; and lubricant. The axial length of the radial dynamic pressure generating portion is formed to be longer than the diameter of the radial dynamic pressure generating portion such that radial dynamic pressure, which is defined with the axial length of the radial dynamic pressure generating portion and the diameter thereof being parameters, is greater than or equal to a predetermined minimum reference value. | 03-17-2011 |
| 20110109995 | BEARING LUBRICANT, BEARING AND DISK DRIVE DEVICE - A bearing lubricant includes a base oil containing an ester compound consisting of 2-ethyl-2-methyl-1,3-propanediol and at least one of carboxylic acids having 5 to 12 carbon atoms, the ester compound being represented by the following formula (1), in which the base oil has a kinetic viscosity at approximately 40° C. of approximately 7 to 15 mPa, and has a pour point of approximately −60° C. or less: | 05-12-2011 |
| 20110181986 | DISK DRIVE DEVICE PROVIDED WITH LUBRICANT-FILLED FLUID DYNAMIC BEARING - In a disk drive device, a hub has an outer circumferential wall portion configured to hold a recording disk. A base member has a cylindrical portion, whose central axis is the rotation axis of the hub, on a surface on the side of the hub. A fluid dynamic bearing holds a lubricant and rotatably supports the hub relative to the base member. A ring-shaped attraction plate including a magnetic material is fixed to the base member and faces a magnet in the axial direction. The outer circumferential wall portion is configured such that the outer circumferential wall portion surrounds the attraction plate and that the range of the outer circumferential wall portion in the axial direction overlaps with the range of the attraction plate in the axial direction. | 07-28-2011 |
| 20110255191 | DISK DRIVE DEVICE - A disk drive device includes a base member; a hub on which a recording disk is placed; a bearing unit arranged on the base member for rotatably supporting the hub; and a spindle drive unit for rotationally driving the hub, wherein the spindle drive unit includes a stator core having salient poles, a coil wound around each of the salient poles, and a magnet having a plurality of magnetic poles arranged in a circumferential direction opposed to the salient poles, the hub includes an outer cylindrical portion formed of a magnetic material and engaged with an inner periphery of the recording disk, and an inner cylindrical portion fixing an outer periphery of the magnet, the number of magnetic poles is an even number in a range of 10 to 16, and the number of salient poles is a multiple of 3 in a range of 12 to 24. | 10-20-2011 |
