Patent application number | Description | Published |
20080212907 | HYDRODYNAMIC BEARING, AND HYDRODYNAMIC BEARING-TYPE ROTARY DEVICE AND RECORDING AND REPRODUCING APPARATUS EQUIPPED WITH SAME - The angular stiffness of a bearing is kept high, and at the same time air inside the bearing is discharged smoothly, without accumulating, which prevents oil film separation on the bearing. With the present invention, a communicating hole is provided, the hole and a radial hydrodynamic groove constitute a circulation path for a lubricant, there is a first thrust bearing face in contact with the circulation path, there is a first hydrodynamic groove on the face, this groove is a herringbone groove with a pump-in pattern, and no low-pressure part is generated in the thrust bearing, so even if the bearing undergoes a pressure change, there is no risk that the air accumulated in a low-pressure part will expand and cause oil film separation on the bearing face. Also, the bubbles are smoothly discharged by circulation of the lubricant in the asymmetrical radial hydrodynamic groove, and there is a pressure distribution such that the pressure generated at the face during bearing rotation is sufficiently high at the outer peripheral portion of the groove pattern, and angular stiffness is high. | 09-04-2008 |
20080304775 | HYDRODYNAMIC BEARING DEVICE, AND RECORDING AND REPRODUCING APPARATUS EQUIPPED WITH SAME - There is provided a hydrodynamic bearing device that maintains high bearing angular stiffness, and that prevents oil film separation in the bearing by smoothly discharging any bubbles present inside the bearing. With a hydrodynamic bearing device, a communicating hole and a radial hydrodynamic groove constitute a circulation path for a lubricant, and a first thrust bearing surface is provided at a location in contact with the circulation path. A first hydrodynamic groove formed in the first thrust bearing surface is a spiral groove with a pump-in pattern. Any bubbles in the bearing are smoothly discharged by the circulation of the lubricant produced by the asymmetrical radial hydrodynamic groove. The pressure generated at the thrust bearing surface during rotation of the bearing has a distribution such that there is a wide range of high pressure. | 12-11-2008 |
20090028474 | HYDRODYNAMIC BEARING DEVICE, AND SPINDLE MOTOR EQUIPPED WITH SAME - There is provided a hydrodynamic bearing device with which the lubricant is prevented from leaking to the outside, and good seal performance can be maintained, and a spindle motor equipped with this hydrodynamic bearing device. The hydrodynamic bearing device comprises a shaft, a sleeve, a lubricant that fills a microscopic gap, a radial bearing portion, a thrust beating portion, and a bearing seal portion. The value of a function P | 01-29-2009 |
20090060403 | SLEEVE FOR HYDRODYNAMIC BEARING DEVICE, HYDRODYNAMIC BEARING DEVICE EQUIPPED WITH SAME, SPINDLE MOTOR, INFORMATION PROCESSING APPARATUS, AND METHOD FOR MANUFACTURING SLEEVE FOR HYDRODYNAMIC BEARING DEVICE - A sleeve for a hydrodynamic bearing device, a hydrodynamic bearing device equipped with the sleeve, a spindle motor, information recording and reproducing and processing apparatus, and a method for manufacturing a sleeve for a hydrodynamic bearing device are provided that are capable of reducing costs through appropriate sealing treatment. | 03-05-2009 |
20090073596 | HYDRODYNAMIC BEARING DEVICE, AND SPINDLE MOTOR AND INFORMATION PROCESSING APPARATUS EQUIPPED WITH THE SAME - A hydrodynamic bearing device comprises a sleeve composed of a sintered member, a shaft that is inserted in a state of being capable of relative rotation into a bearing hole provided to the sleeve, and a hydrodynamic groove formed in the outer peripheral surface of the shaft and/or the inner peripheral surface of the sleeve. The sleeve has a surface porosity of 1.5% or less, and the ridge width is at least 0.10 mm. | 03-19-2009 |
20090154852 | HYDRODYNAMIC BEARING DEVICE, SPINDLE MOTOR, AND INFORMATION RECORDING AND REPRODUCING APPARATUS - The hydrodynamic bearing device comprises a sleeve | 06-18-2009 |
20100052447 | HYDRODYNAMIC BEARING DEVICE, SPINDLE MOTOR, AND INFORMATION DEVICE - The hydrodynamic bearing device has a sleeve composed of a sintered material and having a compression-absorbing space inside the sleeve, the sleeve having a bearing hole in the center thereof; a shaft rotatably inserted into the bearing hole; a bearing portion formed between the bearing hole and the shaft; a hydrodynamic groove formed on at least one of the internal peripheral surface of the bearing hole and the external peripheral surface of the shaft; a concavity having one or more steps and formed to one end of the sleeve in the axial direction; a convexity formed to the other end of the sleeve in the axial direction, the convexity having a shape similar to the concavity; and a lubricating fluid filled in the gap of the bearing portion. The hydrodynamic bearing device has a readily obtainable predetermined shape precision, the internal density of the sintered material is made uniform, and lubricating fluid therein does not leak from the surface. | 03-04-2010 |
20110044837 | SLEEVE FOR HYDRODYNAMIC BEARING DEVICE, HYDRODYNAMIC BEARING DEVICE AND SPINDLE MOTOR USING THE SAME, AND METHOD FOR MANUFACTURING SLEEVE - A bearing stiffness of a sintered metal sleeve is prevented from lowering. A sleeve includes an inner section formed of metal powder for sintering and a resin for impregnation, and a surface deformation section which covers a surface of the inner section and is formed by shot blast process. Since the surface deformation section is formed by the shot blast process, the number of pores formed between the metal powder for sintering near the surface can be reduced. In this way, a supporting pressure at a bearing portion can be prevented from being released out through the pores, and the bearing stiffness can be prevented from lowering. | 02-24-2011 |