Abstract: In order to alleviate mutual interference between axial dynamic pressure portions and a radial dynamic pressure portion in a ring-like hydraulic dynamic pressure bearing, in the case of a ring-like hydraulic dynamic pressure bearing 1 constituted by supporting a shaft portion 4 constituted by fixing a ring 3 to an end portion 2A of a shaft main body 2 by a bearing portion 5, ring-like spaces 8 and 9 for storing lubricant for generating dynamic pressure are provided along contiguous portions of the radial dynamic pressure bearing portion and the axial dynamic pressure bearing portions formed between the ring 3 and the bearing portion 5, and the ring-like spaces 8 and 9 are maintained at atmospheric pressure via paths formed at the bearing portion 5 to thereby prevent negative pressure from generating at boundary regions of the two dynamic pressure bearing portions.

Abstract: The present invention is a double sleeve type fluid dynamic pressure bearing, comprising a fixed shaft having respective ends to be fixed to a utilized apparatus; a rotary sleeve arranged to provide a first fine gap between an inner peripheral surface thereof and an outer peripheral surface of the fixed shaft, a fixed sleeve arranged to provide a second fine gap between an inner peripheral surface thereof and an outer peripheral surface of the rotary sleeve, a holder member arranged to cooperate with a lower end surface of the rotary sleeve to provide a third gap, and wherein the first fine gap and the second fine gap are formed with radial dynamic pressure producing grooves while the third fine gap is formed with a thrust dynamic pressure producing groove, the first, second and third fine gaps being filled with lubrication oil, the first fine gap and the second fine gap having one ends made as opening ends contacting with the air and the other ends made as closed ends communicated with each other through the

Abstract: To provide a motor capable of solidly supporting a stator coil with high rigidity and having inconsiderable vibration and noise, a method of fabricating a motor and a rotary body apparatus, there is provided a motor including a base 10, a sleeve 20 erected on the base, a yoke 41 having a hollow portion in a regular polygonal shape penetrating from one end to other end, the hollow portion being inserted to the sleeve 20 and coaxially fixed to the sleeve 20, a stator coil 40 including coils 42 formed by winding lead wires at a, plurality of locations of the yoke 41, a rotor member 30 supported coaxially with and rotatably by the sleeve 20 and a rotor magnet 60 fixed to the rotor member 30 and urged by rotational magnetic field in which an inner peripheral face portion of the yoke 41 is brought into contact with an outer peripheral face portion of the sleeve 20 at substantially central portions thereof among contiguous ones of corner portions thereof over an entire length along an axial direction and is constitu

Abstract: A spindle motor comprises a base, a stator coil connected to the base, and a sleeve-and-bearing unit connected to a central portion of the base. The sleeve-and-bearing unit has a sleeve and a bearing section mounted in the sleeve having a linear expansion coefficient greater than that of the sleeve. The sleeve has a groove disposed in an outer peripheral surface thereof for receiving an adhesive material for connecting the base to the outer peripheral surface of the sleeve. A rotor unit is connected to the sleeve-and-bearing unit for undergoing rotation relative to the sleeve-and-bearing unit. The rotor unit has a shaft section supported by the bearing section for undergoing rotation, a hub connected to the shaft section for rotation therewith, and a rotor magnet connected to the hub and disposed opposite to and spaced apart from the stator coil.

Abstract: A hydraulic dynamic bearing has a rotational assembly and a bearing member for rotationally supporting the rotational assembly. The bearing member has a main body having a recess portion and a cover for covering an open end of the recess portion. The rotational assembly has a shaft main body having an end portion extending into the recess of the bearing main body for undergoing rotation relative thereto and a ring member disposed in the recess of the bearing main body. The ring member is connected to the end portion of the shaft main body for rotation therewith. Axial dynamic pressure generating grooves are formed in upper and lower surface portions of the ring member for generating axial dynamic pressure during rotation of the rotational assembly. Radial dynamic pressure generating grooves are formed in an outer peripheral surface portion of the ring member for generating radial dynamic pressure during rotation of the rotational assembly.

Abstract: In a method for assembling a spindle motor having a liquid dynamic pressure bearing having a flanged shaft member formed by press-fitting a dynamic pressure ring member on a cylindrical member, a hub is press-fit on the flanged shaft member without causing deviation in the press-fit position of the dynamic pressure ring member. A hub press-fitting apparatus press fits a mount hole of the hub on a cylindrical end portion of the cylindrical member. The hub press-fitting apparatus comprises a hub holding member, a rotation shaft member, a coupling member, and an anti-rotation member. During assembly, a temporary coupling between the hub press-fitting apparatus and the liquid dynamic pressure bearing is made by screwing a threaded tap in a tap hole provided in an end face of the cylindrical member.