Abstract: A conical bearing member includes a communication hole communicating an inner peripheral surface and an outer peripheral surface of the conical bearing member, and the inner peripheral surface includes a press-fit region in contact with a shaft and an enlarged diameter region having a diameter greater than a diameter of the press-fit region and including an inner opening part of the communication hole. A tapered part having a diameter increasing toward the enlarged diameter region is provided at an end part of the press-fit region on the enlarged diameter region side.

Abstract: A base member serving as a part of a housing of a hard disk drive device. The base member includes a base body being a cast product, a machined surface obtained by machining a part of the base body at a side of an interior of the housing, an impregnating agent filled into a casting cavity exposed at the machined surface, and a coating film covering a surface including the machined surface of the base body.

Abstract: A base member serving as a part of a housing of a hard disk drive device. The base member includes a base body being a cast product, a machined surface obtained by machining a part of the base body at a side of an interior of the housing, an impregnating agent filled into a casting cavity exposed at the machined surface, and a coating film covering a surface including the machined surface of the base body.

Abstract: A spindle motor according to an embodiment includes a base plate, a rotor magnet fixed to a rotor assembly positioned at one surface side of the base plate and a magnetic attraction plate fixed at the one surface side of the base plate so as to face the rotor magnet. An opposite area of the base plate facing the magnetic attraction plate includes a coated area covered by an epoxy electric discharge coating film, and the magnetic attraction plate is fixed to the opposite area via at least one of an epoxy adhesive and an acrylic adhesive.

Abstract: A spindle motor according to one aspect of the present disclosure includes a shaft member, a baseplate having a through hole in which the shaft member is inserted and fixed, and a rotor member disposed on one side in an axial direction of the baseplate and rotatably supported through the shaft member. In a peripheral groove formed in an inner peripheral surface of the through hole, a gap between the shaft member and the baseplate is sealed by adhesive on the one side in the axial direction and the other side in the axial direction opposite to the one side, so that a confined volume of air is formed.

Abstract: A spindle motor according to an embodiment includes a base plate, a rotor magnet fixed to a rotor assembly positioned at one surface side of the base plate and a magnetic attraction plate fixed at the one surface side of the base plate so as to face the rotor magnet. An opposite area of the base plate facing the magnetic attraction plate includes a coated area covered by an epoxy electric discharge coating film, and the magnetic attraction plate is fixed to the opposite area via at least one of an epoxy adhesive and an acrylic adhesive.

Abstract: A fluid dynamic pressure bearing device includes a shaft member (5) and a bearing member (41), at least one of the shaft member or the bearing member being rotatable with respect to the other. A shaft member-side annular member (13) is fixed with respect to the shaft member. The shaft member-side annular member includes a large-diameter rim portion and a small-diameter outer circumferential surface portion. A bearing member-side annular member (14) is fixed with respect to the bearing member. The bearing member-side annular member includes an inner circumferential large-diameter step portion, and a small-diameter inner circumferential surface portion.

Abstract: A fluid dynamic bearing mechanism for a motor (1) suitable for use in a hard disk drive and having a compact and thin shape, high bearing rigidity, and high rotating accuracy, and which securely keeps the rotor member (6) in place against shocks, and allows the inspection of lubricant supply amount easily. A fluid dynamic bearing mechanism having a capillary seal part (12) on one end of lubricant supply part formed by a minute gap including dynamic pressure grooves (10) formed on a shaft member (5) or a bearing member (4) is provided. An annular member (13) is fitted on the shaft member at the location corresponding to the capillary seal part, another annular member (14) is fitted on the bearing member at the location corresponding to the capillary seal part, a taper or step (13a, 14a) is formed on the outer peripheral surface of the annular member on the shaft member side and the inner peripheral surface of the annular member on the bearing member side.

Abstract: A fluid dynamic pressure bearing device includes a shaft member (5) and a bearing member (41), at least one of the shaft member or the bearing member being rotatable with respect to the other A shaft member-side annular member (13) is fixed with respect to the shaft member. The shaft member-side annular member includes a large-diameter rim portion and a small-diameter outer circumferential surface portion. A bearing member-side annular member (14) is fixed with respect to the bearing member. The bearing member-side annular member includes an inner circumferential large-diameter step portion, and a small-diameter inner circumferential surface portion.

Abstract: A fluid dynamic pressure bearing includes dynamic pressure grooves formed between a shaft member and a bearing member. The shaft member includes a flange portion 1-2, and a capillary seal portion 8 is formed between an outer circumferential surface of the flange portion and an inner circumferential surface of the bearing member. An annular labyrinth member 4 is engaged with an upper portion of the bearing, and a labyrinth seal portion is defined by (i) an annular protrusion 1-4 formed on an upper end surface of the flange portion and facing the labyrinth member via a micro gap and/or (ii) an annular protrusion 4-2 formed on a lower end surface of the labyrinth member and facing the flange portion via a micro gap.

Abstract: A fluid dynamic bearing mechanism for a motor (1) suitable for use in a hard disk drive and having a compact and thin shape, high bearing rigidity, and high rotating accuracy, and which securely keeps the rotor member (6) in place against shocks, and allows the inspection of lubricant supply amount easily. A fluid dynamic bearing mechanism having a capillary seal part (12) on one end of lubricant supply part formed by a minute gap including dynamic pressure grooves (10) formed on a shaft member (5) or a bearing member (4) is provided. An annular member (13) is fitted on the shaft member at the location corresponding to the capillary seal part, another annular member (14) is fitted on the bearing member at the location corresponding to the capillary seal part, a taper or step (13a, 14a) is formed on the outer peripheral surface of the annular member on the shaft member side and the inner peripheral surface of the annular member on the bearing member side.

Abstract: A fluid dynamic pressure bearing is constituted in which a shaft member, including thrust plates 5 engaged with small-diameter portions at both ends of a shaft 1, is relatively rotatably combined with a bearing member via radial and axial dynamic pressure bearings. The bearing member includes a casing 3, a sleeve assembly body engaged to the casing 3, and seal rings 6 engaged to end portions of the casing 3. The sleeve assembly body is constituted by two or more sleeve elements 2 and a spacer sleeve element 4 coaxial with and sandwiched between the sleeve elements 2. Capillary seal portions 9 are formed between the thrust plates 5 and the seal rings 6. Highly accurate finishing of the dynamic pressure bearing portions, capillary seal portions, etc. can easily be accomplished by an easy, highly accurate processing, even if the shaft member or bearing member of a spindle motor becomes longer as a memory capacity of a memory device is increased.

Abstract: A production method for sintered bearing member comprises: compacting a metal powder into a green compact, sintering the green compact into a sintered compact; impregnating a resin solvent into the sintered compact, and removing the resin solvent adhering to a surface of the sintered compact, thereby exposing a matrix as sintered on a surface of the sintered compact. Pores existing in portions other than the surface are sealed with the resin.

Abstract: A hydrodynamic bearing system, particularly for the rotary bearing of spindle motors to power hard disk drives. The bearing system includes a bearing sleeve, a shaft accommodated in an opening in the bearing sleeve and at least one radial bearing section provided between the bearing sleeve and the shaft with the aid of which the shaft and the bearing sleeve are supported rotatably in relation to each other. A bearing gap is formed between the shaft and the bearing sleeve and is filled with a liquid lubricant. A lubricant reservoir and equalizing volume independent from the design of the bearing arrangement is provided in that at least one duct is formed in the bearing sleeve that extends from an outer section of the bearing sleeve to the bearing gap and that is at least partially filled with lubricant.

Abstract: In a fluid dynamic pressure bearing device, a shaft member includes a shaft member-side annular member, and end surfaces of the shaft member and/or the shaft member-side annular member contact a base member of a motor. The shaft member is fixed to the base member. A bearing member is rotatably engaged with the shaft member, and a rotor hub of the motor is engaged with the bearing member. A bearing member-side annular member engaged with the rotor hub suppresses the bearing member from being pulled out in the direction of the base member. A capillary seal portion is formed by a micro gap between the shaft member-side annular member and the bearing member-side annular member. The capillary seal portion suppresses leakage of lubricant occupying the micro gap.

Abstract: A production method for sintered bearing member comprises: compacting a metal powder into a green compact, sintering the green compact into a sintered compact; impregnating a resin solvent into the sintered compact, and removing the resin solvent adhering to a surface of the sintered compact, thereby exposing a matrix as sintered on a surface of the sintered compact. Pores existing in portions other than the surface are sealed with the resin.

Abstract: A hydrodynamic bearing system, particularly for the rotary bearing of spindle motors to power hard disk drives. The bearing system includes a bearing sleeve, a shaft accommodated in an opening in the bearing sleeve and at least one radial bearing section provided between the bearing sleeve and the shaft with the aid of which the shaft and the bearing sleeve are supported rotatably in relation to each other. A bearing gap is formed between the shaft and the bearing sleeve and is filled with a liquid lubricant. A lubricant reservoir and equalizing volume independent from the design of the bearing arrangement is provided in that at least one duct is formed in the bearing sleeve that extends from an outer section of the bearing sleeve to the bearing gap and that is at least partially filled with lubricant.

Abstract: In an outer rotor type spindle motor for driving a disc with a relatively long axial dimension for mounting a large number of the discs, it is possible to reduce part cost and assembling work cost while increasing a rotational precision. The stator is disposed on an opening surface of a drum portion of the rotor rather than between a pair of bearings within the drum portion. The stator coil end may be led to the outside of the drum portion without passing through the bearing to dispense with the conventional works such as a processing of a shaft, an insertion of a lead wire through a tubular hole and the like. Also, a bush between the drum portion and the bearing, which conventionally causes the degradation of the rotational precision and the increases in the cost for the parts and the assembling work, is dispensed with.

Abstract: In a spindle motor in which its weight is decreased while maintaining the rigidity of a bearing to a large value, the widthwise dimension of a bearing cartridge assembly 11 is set so that the upper outer ring end portion 12b of the outer ring 12 of the bearing cartridge assembly 11 protrudes from a hub main body 6A. Since the lengthwise dimension of a hub 5A is smaller than that of a prior art, the weight and cost can be decreased that much. Further, the lengthwise dimension of the hub 5A is smaller than that of the prior art, a space portion is increased and the space portion can be employed as a space for arranging various kinds of members. Since the upper outer ring end portion 12b protrudes from the hub main body 6A, fitting pressure is not exerted on the upper outer ring end portion 12b of the outer ring 12 upon fitting, so that the generation of unnecessary deformation or the like can be avoided.

Abstract: In a spindle motor in which its weight is decreased while maintaining the rigidity of a bearing to a large value, the widthwise dimension of a bearing cartridge assembly 11 is set so that the upper outer ring end portion 12b of the outer ring 12 of the bearing cartridge assembly 11 protrudes from a hub main body 6A. Since the lengthwise dimension of a hub 5A is smaller than that of a prior art, the weight and cost can be decreased that much. Further, the lengthwise dimension of the hub 5A is smaller than that of the prior art, a space portion is increased and the space portion can be employed as a space for arranging various kinds of members. Since the upper outer ring end portion 12b protrudes from the hub main body 6A, fitting pressure is not exerted on the upper outer ring end portion 12b of the outer ring 12 upon fitting, so that the generation of unnecessary deformation or the like can be avoided.