Abstract: With a hydrodynamic bearing device 10, a first gap G1 is formed between a shaft 12 and a sleeve 11. A second gap G2 is formed between a sleeve cap 16 and the sleeve 11, and holds a lubricant 17. A thrust bearing member 21 is disposed near the inner peripheral surface of a center hole 16a of the sleeve cap 16. A third gap G3 is formed between the thrust bearing member 21 and the sleeve cap 16, and is open to the atmosphere. A fourth gap G4 is formed between the thrust bearing member 21 and the sleeve 11. The lubricant 17 circulates along a circulation passage that includes a communicating path 11b, the first gap G1 and the second gap G2.

Abstract: With a hydrodynamic bearing device 10, a first gap G1 is formed between a shaft 12 and a sleeve 11. A second gap G2 is formed between a sleeve cap 16 and the sleeve 11, and holds a lubricant 17. A thrust bearing member 21 is disposed near the inner peripheral surface of a center hole 16a of the sleeve cap 16. A third gap G3 is formed between the thrust bearing member 21 and the sleeve cap 16, and is open to the atmosphere. A fourth gap G4 is formed between the thrust bearing member 21 and the sleeve 11. The lubricant 17 circulates along a circulation passage that includes a communicating path 11b, the first gap G1 and the second gap G2.

Abstract: A hydrodynamic bearing device (30) comprises a shaft (31), a sleeve (32) in which the shaft (31) is installed so as to be able to rotate in relative fashion, a lubricant (34) filled into a minute gap between the shaft (31) and the sleeve (32), a sleeve cover (35) attached to the upper end surface of the sleeve (32), a lubricant reservoir (50) for retaining the lubricant (34) between the sleeve (32) and the sleeve cover (35), and flow suppressing parts (51a, 51b) formed inside the lubricant reservoir (50) so as to protrude in an axial direction.

Abstract: There is provided a hydrodynamic bearing device having a communicating hole and with a bearing structure such that lubricant tends not to flow out of the bearing openings of the hydrodynamic bearing device even when the hydrodynamic bearing device is subjected to a large impact, as well as a spindle motor in which this hydrodynamic bearing device is installed. A hydrodynamic bearing device has a shaft and a sleeve that rotatably supports the shaft. A thrust flange is formed at one end of the shaft, is equipped with a protrusion that is opposed to a stepped component of the sleeve in the axial direction, and is configured such that the thrust flange does not block a communicating hole when an impact is applied, which suppresses the generation of a cavity near the thrust flange.

Abstract: A fluid bearing device 40 comprises a sleeve 1, a shaft 2, a thrust plate 4, a radial bearing component 21, and a thrust bearing component 22. A bearing hole 1a is formed in the sleeve 1. The shaft 2 has a shaft main component 5 that is inserted in the bearing hole 1a, and a flange 3 provided on the axial lower side of the shaft main component 5. The thrust plate 4 is fixed to the sleeve 1 and covers the shaft 2 from the axial lower side. A screw hole 5a that is coaxial with the shaft main component 5 is formed in the shaft main component 5 from the end face on the axial upper side toward the axial lower side. An annular concave component 3c that is coaxial with the shaft 2 is formed in the end face on the axial lower side of the shaft 2.

Abstract: A hydrodynamic bearing device includes a sleeve having a bearing bore substantially at a center portion, a shaft inserted in the bearing bore in a rotatable manner, a thrust plate for supporting an end of the shaft in the thrust direction and an upper retaining portion that has an opening portion through which the shaft passes and covers the upper surface of the sleeve. A radial hydrodynamic bearing is formed between the bearing bore of the sleeve and the shaft, while a thrust hydrodynamic bearing is formed between the thrust plate and an end of the shaft. A first space is formed between the upper surface of the sleeve and the upper retaining portion. A second space is formed between the upper retaining portion and a step portion.

Abstract: A recess (27) is formed in a hub flange surface (21) concentrically with a rotation center axis of a spindle hub (7). The hub flange surface (21) contacts a disk surface (20) at positions on opposite sides of the recess (27) in a radial direction of the disk.

Abstract: A hydrodynamic bearing device includes a sleeve having a bearing bore substantially at a center portion, a shaft inserted in the bearing bore in a rotatable manner, a thrust plate for supporting an end of the shaft in the thrust direction and an upper retaining portion that has an opening portion through which the shaft passes and covers the upper surface of the sleeve. A radial hydrodynamic bearing is formed between the bearing bore of the sleeve and the shaft, while a thrust hydrodynamic bearing is formed between the thrust plate and an end of the shaft. A first space is formed between the upper surface of the sleeve and the upper retaining portion. A second space is formed between the upper retaining portion and a step portion.