A dynamic pressure bearing device enabling the prevention of the deterioration of accuracy in its assembling and the lowering of strength and also enabling a reduction in cost. A guide face (2c) used as a guide when a disk hub (3) is press-fitted onto a shaft member (2) is formed on the shaft member. Then, the guide face (2c), the outer peripheral surface (2a3) of the shaft member (2) adjacent to the guide face (2c), and a boundary part between the guide face (2c) and the outer peripheral surface (2a3) are simultaneously ground to form an obtuse part (2d) with radius (r) at the boundary part. Since edges between the guide face (2c) and the outer peripheral surface (2a3) are eliminated, a press-fitting resistance produced when the disk hub is press-fitted onto the shaft end of the shaft member (2) can be reduced.

Dynamic pressure bearing device

A motor includes a shaft component, an upper plate portion, a lower plate portion, and a sleeve portion. The shaft component includes an inner shaft portion and an outer shaft portion. The upper plate portion defines a single monolithic member with one of the inner shaft portion and the outer shaft portion. The lower plate portion defines a single monolithic member with the other of the inner shaft portion and the outer shaft portion. The sleeve portion is disposed between the upper plate portion and the lower plate portion. A radial gap is defined between the sleeve portion and the outer shaft portion. A fixing range in which the outer shaft portion and the inner shaft portion radially overlap is arranged. At least a portion in an axial direction of the fixing range radially overlaps with an existing range in the axial direction of the radial gap.

Motor and disk drive apparatus

A fluid dynamic pressure bearing has an annular dynamic pressure generating face having a dynamic pressure generating groove, which draws a working fluid toward a midway position in the radial direction from the inside and outside of a thrust bearing plate in the radial direction when a shaft and a housing are rotated relative to each other. The dynamic pressure generating groove is provided on thickness direction end faces of the thrust bearing plate or on an inner surface of the housing, and an inner groove section is located on an inner peripheral side of the dynamic pressure generating face on the end faces and is recessed more than the dynamic pressure generating face in the thickness direction. A through-hole extends through the thrust bearing plate in the thickness direction so as to open to the dynamic pressure generating face, and a communicating cavity connects the opening portion of the through-hole and the inner groove section.

Fluid dynamic pressure bearing, motor, and recording medium driving device

A spindle motor for magnetic disc device includes a hub having an inside and an outer peripheral side on which a magnetic disc is mounted, a rotary shaft having an axial direction and coupled with the hub so as to be integrally rotated therewith, with the motor being arranged on the inside of the hub. The hub, the rotary shaft and a part of the motor constitute a rotary body. A radial bearing having a length in the axial direction of the rotary shaft, for supporting the rotary body in a direction crossing the rotary shaft, and a thrust bearing for supporting the rotary body in the axial direction of the rotary shaft are provided. The thrust bearing has an outer diameter greater than the length of the radial bearing, and is arranged at a position which is inside of the motor and diametrically inward of the hub.

Spindle motor and magnetic disc device using thereof having radial and thrust bearings

A downsized spindle motor having a longer bearing service life and enhanced shock resistance includes a flange 11, which bears an axial load of a shaft 8, and which is fixed to an end of shaft 8. Laser welded section 14 is provided at the fixed section between shaft 8 and flange 11. Rotor hub 50 is fixed to another end of shaft 8, and laser welded section 54 firmly bonds the two elements.

Spindle motor and method for assembling the same

PROBLEM TO BE SOLVED: To reduce mutual interference of an axial dynamic pressure part and a radial dynamic pressure part on a ring liquid dynamic pressure bearing. SOLUTION: Ring spaces 8, 9 to reserve lubricating oil for generation of dynamic pressure are provided along a neighbouring part of a radial dynamic pressure bearing part and an axial dynamic pressure bearing part formed between a ring 3 and a bearing part 5 and negative pressure is not generated in a boundary region of both of the dynamic pressure bearing parts in a ring liquid dynamic pressure bearing 1 constituted as a shaft part 4 constituted with the ring 3 fixed on an end part 2A of a shaft main body 2 supported by the bearing part 5. COPYRIGHT: (C)2000,JPO

Liquid dynamic pressure bearing and the spindle motor

PROBLEM TO BE SOLVED: To provide an optical fiber collimator with which stable coupling efficiency can be obtained and the reliability is improved while the cost is reduced. SOLUTION: A member for holding a ferrule 20 and an optical lens 31 is composed of a lens barrel 32 for holding the optical lens 31 and a holder 40 for holding the ferrule 20. The lens barrel 32 and the holder 40 are each formed with a member having a different thermal expansion coefficient and joined so as to be abutted on each other on the outer side of the axial direction than the optical lens 31 and the ferrule 20. A distance L 1 in the axial direction between the positioning point of the holder 40/ferrule 20 and the abutting point of the holder 40/lens-barrel 32, as well as a distance L 2 between the positioning point of the lens-barrel 32/optical lens 31 and the abutting point, is set so that the tip end face of the optical fiber 1 is arranged at the focal position of the optical lens 31, by the thermal expansion coefficients α 1 , α 2 and α 3 of the holder 40, the lens-barrel 32 and the optical lens 31 respectively, and also by the focal distance f of the optical lens 31. COPYRIGHT: (C)2004,JPO

Optical fiber collimator

PROBLEM TO BE SOLVED: To enhance a load for support, and prevent lubricating oil from leaking when a fluid bearing in which both ends of a shaft is fixed is inclined. SOLUTION: A double sleeve-type fluid dynamic pressure bearing is constituted of a fixed shaft 1, a rotation sleeve 2 disposed such that a first small gap 5 is formed between an inner peripheral surface thereof and an outer peripheral surface of the fixed shaft 1, a fixed sleeve 3 disposed such that a second small gap 6 is formed between an inner peripheral surface thereof and an outer peripheral surface of the rotation sleeve 2, and a holder member 4 disposed such that a third small gap 7 is formed between the holder member 4 and a lower end surface of the rotation sleeve 2. Each of one end of the first small gap 5 and the second small gap 6 serves as opening ends 11, 12 which are exposed to an atmosphere, respectively, and each of another ends of the first and second gaps 5, 6 serves as a closed end which communicates with each other via the third small gap 7. These small gaps 5, 6 and 7 are filled with lubricating oil 18. Axial dynamic pressure generating grooves 8a, 8b, 8c and 8d are provided to the first and second small gaps 5 and 6, and a thrust dynamic pressure generating groove 9 is provided to the third small gap 7.

Fluid dynamic pressure bearing, spindle motor, and rotor device

PROBLEM TO BE SOLVED: To attach a hub to a shaft member having a flange by pressing-in without generating any shifts in the pressing-in position of a dynamic pressure ring member in the assembling of a spindle motor equipped with a liquid dynamic pressure bearing having the shaft member having the flange formed by pressing the dynamic pressure ring member into a cylindrical member. SOLUTION: Not a pressing force but a pulling force is applied to a liquid dynamic pressure bearing equipped with a flange shaft member formed by pressing a dynamic pressure ring member 3 into a cylindrical member 2, and the attaching hole of a hub 6 is pressed into the cylindrical end part 2b of the cylindrical member 2 by a hub pressing-in device 10. The hub pressing- member 10 is provided with a hub pressing member 11, a rotary shaft member 12, a coupling member 13 and a rotation preventing member 14. The temporary coupling of the hub pressing-in device 10 with the liquid dynamic pressure bearing is carried out by fitting the screw tap of the coupling member 13 in a tap hole provided in the end surface of the cylindrical member 2.

隆文鈴木

Papers

Liquid dynamic pressure bearing and the spindle motor

Optical fiber collimator

Fluid dynamic pressure bearing, spindle motor, and rotor device

Spindle motor and its assembling method

隆文 鈴木

Papers

Liquid dynamic pressure bearing and the spindle motor

Optical fiber collimator

Fluid dynamic pressure bearing, spindle motor, and rotor device

Spindle motor and its assembling method

隆文鈴木