Minebea Mitsumi Inc.

Daigo Nakajima

Hideaki Showa

Kazuo Ota

Tetsuo Kitamura

Daisuke Ito

Sendy Hanzel

Tobias Imberger

Christoph Fluck

The spindle motor includes; a shaft including a shaft portion and a flange portion, the shaft portion having a columnar shape extending in an axial direction, the shaft portion including a shaft end portion, the flange portion being provided at the shaft end portion and receiving a load in the axial direction; and a bearing sleeve rotatably supporting the shaft, the bearing sleeve having a tubular shape including a sleeve end portion having a large-diameter recess part formed in the axial direction. The shaft is a member formed of a copper alloy containing from 0.5 mass percent to 1.5 mass percent of silicon and from 0.5 mass percent to 3.0 mass percent of manganese, and the member includes the shaft portion and the flange portion integrated with one another.

Spindle motor and hard disk drive device

A fluid dynamic bearing device prevents an oleophobic agent from wetting and spreading to a tapered seal portion, including lubricating oil C filled in a condition in which the oil is separated sandwiching a separator portionholding a gas layer arranged between two conical bearing members, and two primary tapered seal portionseach connecting to one of both ends along an axial direction of the separator portion, wherein width in a radial direction of the two primary tapered seal portiondecreases as each approaches toward the two conical bearing members, a gas-liquid interface of the lubricating oil C is located each of the two primary tapered seal portions, an oleophobic agent blocking portionis arranged at each of both ends in an axial direction of the separator portion, a separator central portionis arranged between the oleophobic agent blocking portionsof the separator portions, and an oleophobic coating is formed at least at the separator central portionof the separator portion

Fluid dynamic bearing device, spindle motor, and hard disk drive device

A spindle motor according to one aspect of the present disclosure includes: a hub; a yoke; a rotor magnet; and a stator. The hub is formed in a cup shape having a hub cylindrical part extending in an axial direction and a disk part extending radially inward from an end of the hub cylindrical part. The yoke being arranged on radially inward of the hub is formed in an annular shape having a yoke cylindrical part facing the hub cylindrical part and a yoke flange part facing the disk part and extending radially inward from the one end of the hub cylindrical part. The disk part includes an adhesive part with the yoke flange part being fixed via an adhesive and a peripheral groove being formed on radially outward of the adhesive part. The adhesive is not present on radially outward of the peripheral groove, and the hub cylindrical part and the yoke cylindrical part do not contact each other.

Spindle motor

A spindle motor includes a base plate on which a through hole is formed, a stator assembly provided at an top side of the base plate having a stator core with stator windings, a circuit board provided at the bottom side of the base plate and to which a lead wire of the stator windings drawn from the through hole to the bottom side is connected. An insulating cover sheet is provided at the top side of the base plate for covering the through hole, the insulating cover sheet being passed through by the lead wire, and a sealing material filling the through hole. The insulating cover sheet has a wire hole and an air vent part communicating with the through hole, wherein the air vent part faces at least a portion of an inside opening of the through hole. The wire hole and the air vent part are separated from each other or are connected to form a single opening.

A spindle motor includes a base plate in which a through hole is formed, a stator core that is provided inside the base plate and is wound with a coil, and a circuit board that is provided outside the base plate and to which a conducting wire of the coil drawn out to outside through the through hole is connected, wherein the through hole includes an inner opening that opens inward of the base plate, an outer opening that opens outward of the base plate, and an intermediate portion having a cylindrical shape that is provided between the inner opening and the outer opening, an enlarged opening is formed to be connected to the outer opening, the enlarged opening is offset to extend toward a side where the circuit board is not present, and the through hole is sealed with a sealing material.

A spindle motor includes a base plate to which a shaft is fixed, an annular stator core that is fixed to the base plate and is wound with a plurality of stator coils, and a rotor member that is attached in a rotatable state to the shaft and includes an inner sleeve portion facing an inner peripheral side of the stator core with an inner clearance and an outer sleeve portion facing an outer peripheral side of the stator core with an outer clearance, an annular groove is formed on an outer periphery of the inner sleeve portion, and the annular groove overlaps with the plurality of stator coils as viewed from a direction perpendicular to the shaft.

A fluid dynamic pressure bearing includes a conical bearing member having a conical bearing surface forming a first gap between a member constituting the rotor. A second gap connected to one end of the first gap and provided over the entire periphery of the shaft is formed between the conical bearing member and the shaft. A tapered seal portion is formed between the conical bearing member and the rotor. The conical bearing member is provided with a circulation hole that communicates the second gap and the tapered seal portion. The circulation hole communicates to another end of the first gap through a part of the tapered seal portion, so that the circulation hole and the other end of the first gap are spaced apart.

Growing community of inventors

Tomi, Japan

Daigo Nakajima