A dynamic pressure bearing device includes a rotary shaft, a dynamic pressure bearing member for supporting the rotary shaft, two radial dynamic pressure bearing parts and a thrust dynamic pressure bearing part formed between the dynamic pressure bearing member and the rotary shaft, and a lubricating fluid continuously filled in the two radial bearing parts and the thrust bearing part. A bypass passage for pressure release is provided for communicating across the two radial dynamic pressure bearing parts to flow the lubricating fluid corresponding to the amount of the unbalance caused by the unbalance of the pumping effect forces from a high-pressure side to a low-pressure side through the bypass passage to reduce the unbalance.

Dynamic pressure bearing device

A single-reel magnetic tape cartridge has a cartridge casing and a single reel around which a magnetic tape is wound and which is contained in the cartridge casing for rotation, in which the magnetic tape is fixed at the leading edge thereof to a leader pin employed for extracting the magnetic tape from the cartridge and the flanges at the upper and lower ends of the leader pin are engaged by the lateral drawing force of a latch spring removably held in the tape cartridge casing. Even for cases in which there is a deviation in the insertion position in which leader pin is inserted by the record and playback apparatus, etc. causing the entry path of the leader pin into the cartridge casing to be off track, etc., it is still possible for the leader pin to be inserted into the cartridge casing. The incline angle, in relation to the insertion direction of the leader pin, at the point at which the flanges of the leader pin are brought into abutment with the guide surface of the latch spring is set within the range of 30°±5°.

Magnetic tape cartridge

The preset invention aims to improve the assembly accuracy and rotation accuracy of a fluid bearing device, and to further reduce the cost thereof. A bearing sleeve is fixed on the inner periphery of a housing. An axial member is supported in a non-contact manner in a radial direction by an oil film formed in a radial bearing gap. The housing made of resin is injection molded with the use of a substrate as an insert part. On the substrate, a control circuit for controlling a polygon scanner motor is mounted.

Fluid bearing device

A fluid dynamic bearing device which exhibits high bearing performance at low cost has a highly accurate bearing gap. At least a region in the outer circumferential surface of a shaft, which faces the radial bearing gap, is constituted of an electroformed part, and the region of the shaft excluding the electroformed part is constituted of a resin portion.

Fluid dynamic bearing device

A stator portion of a spindle motor includes a substantially cup-shaped base member including a bottom portion expanding in a radial direction, and a wall portion extending upwards from an outer edge portion of the bottom portion. A circuit board is fixed to a lower surface of the base member in a position on the outer side in the radial direction and on the upper side than the bottom portion. Accordingly, the thickness of the spindle motor in the axial direction can be reduced. The base member has a through hole formed axially through the bottom portion. An opening edge portion of the base member is covered with the insulating layer. A conducting wire from a coil is drawn through the through hole, led out along the surface of the insulating layer, and connected to the circuit board positioned on the outer side in the radial direction than the bottom portion. Accordingly, the conducting wire can be led to the circuit board while the electric connection between the conducting wire and the opening edge portion can be prevented.

Spindle motor and disk drive apparatus

A dynamic pressure type bearing comprises a sleeve rotatably holding a shaft driven by a motor composed of a rotor and a stator, one or both of the sleeve and the shaft being made of a resin material. The sleeve and/or shaft of a resin material may have a thin film of oil or grease formed on the surface thereof. Preferably, the resin material has load flexible temperture of 120° C. or more, modules of elasticity or bending of 10 GPa or more, and coefficient of linear expansion of 3×10-5 /°C. or less.

Dynamic pressure type bearing device

The porous oil-impregnated bearing 1 comprises a bearing body 1 a made of a porous material, and oil retained in the pores of the bearing body 1 a by impregnation with lubricating oil or lubricating grease. The inner peripheral surface of the bearing body 1 a is formed with a bearing surface 1 b opposed to an outer peripheral surface of a shaft to be supported, with a bearing clearance defined therebetween. The bearing surface 1 b has a first region m 1 in which a plurality of hydrodynamic pressure generating grooves 1 c inclined in one direction with respect to the axial direction are circumferentially disposed, a second region m 2 which is axially spaced from said first region m 1 and in which a plurality of hydrodynamic pressure generating grooves 1 c inclined in the other direction with respect to the axial direction are circumferentially disposed, and an annular smooth region n disposed between the first and second regions m 1 and m 2.

Hydrodynamic type porous oil-impregnated bearing

The squareness of the both end surfaces of the flange portion with respect to the outer circumference of the shaft portion of the shaft member is set to 0.001 mm or less respectively, and the flatness of both end surfaces of the flange portion is set to 0.001 mm or less respectively. The squareness of the end surface of the bearing member with respect to the inner circumference of the bearing member is set to 0.002 mm or less, and the flatness thereof is set to 0.0015 mm or less. The flatness of the inner surface of the bottom portion of the housing is set to 0.002 mm or less.

Hydrodynamic bearing unit

A thrust bearing section (14) is constituted by one bearing end face (11 f 1) of a hydrodynamic type oil-impregnated sintered bearing (11) and a flange portion (13 a) provided on a rotating shaft (13). The squareness between the bearing end face (11 f 1) and the bearing inner periphery (11 h) is set within 3 μm, and the squareness between the flange portion (13 a) and the outer periphery of the rotating shaft (13) is set within 2 μm. The bearing bore diameter d and the bearing length L of the hydrodynamic type oil-impregnated sintered bearing are set as L≦1.2 d, and a radial bearing surface (11 b) is arranged at one place on the bearing inner periphery (11 h).

Hydrodynamic type bearing and hydrodynamic type bearing unit

Two bearing bodies 1 each having a bearing surface 17 are force-fitted into a housing 7 which is opened at one end and closed at the other end thereof, and a shaft 2 (rotary shaft) is inserted in the bearing bodies 1, thereby forming two axially spaced porous oil-impregnated bearings A The inner peripheral surfaces of the bearing bodies 1 and the oil leak preventing member 11 are formed with a plurality of inclined grooves (hydrodynamic-pressure-generating grooves 5 and air current producing grooves 12) A solid lubricating composition 3 composed of synthetic resin as a base material and oil as a lubricating component by blending lubricating oil or lubricating greases is disposed between the two bearing bodies 1

Natsuhiko Mori

Papers

Dynamic pressure type bearing device

Hydrodynamic type porous oil-impregnated bearing

Hydrodynamic bearing unit

Hydrodynamic type bearing and hydrodynamic type bearing unit

Hydrodynamic type porous oil-impregnated bearing and bearing device