Abstract: A base plate includes a bottom wall and a peripheral wall. The peripheral wall extends from the bottom wall to an axially upper side. The bottom wall includes a screw hole recessed from a peripheral edge of a lower end surface of the bottom wall to the axially upper side. The screw hole includes an inclined part and a column body. The inclined part is defined to have an inner diameter that decreases from a lower end toward the axially upper side. The column body extends from an upper end of the inclined part to the axially upper side and is defined with a threaded part. In a cross section including a center line that passes through a center of the column body in an axial direction, the inclined part is inclined at an inclination angle of 25° or more and 35° or less with respect to the center line.

Abstract: This base plate constitutes a part of a housing of a disk drive device, and is formed from a metal plate and a die-cast part. The metal plate includes a board-shaped bottom plate portion that spreads out perpendicular to an up-down extending axis of rotation of a disk. The die-cast part covers at least a part of the bottom plate portion. Metal which constitutes the bottom plate portion is higher in rigidity than metal which constitutes the die-cast part.

Abstract: A base plate becomes a part of a housing of a disk drive device and is made of a metal die-cast member. The base plate includes a bottom wall portion and a cylindrical wall portion. The bottom wall portion extends perpendicular to a rotation axis of a disk extending in a vertical direction. The cylindrical wall portion protrudes upward from an upper surface of the bottom wall portion along the rotation axis and has a shaft through hole through which a shaft is inserted. The cylindrical wall portion has an annular stepped portion that protrudes radially outward from an outer peripheral surface of a root portion. A processed surface is formed on at least a part of an outer peripheral surface of the stepped portion.

Abstract: A disk driving device includes a disk, a motor, an arm, a head, and a housing. The disk rotates about a rotation shaft extending in a vertical direction. The motor causing the disk to rotate. The arm swings about a swinging shaft which is disposed at a position different from the rotation shaft and which extends in the vertical direction. The head is disposed at a tip of the arm and is configured to perform reading or writing of information from or to the disk. The housing accommodates the disk, the motor, the arm, and the head. The housing includes a base plate, a cover, a pivot post, a tubular portion, and a screw. The base plate is a cast product and has a box shape including a bottom wall extending perpendicularly to the rotation shaft and an open top. The cover has a plate shape covering an opening of the base plate. The pivot post is a member separate from the base plate and protrudes upward from a top surface of the bottom wall along the swinging shaft.

Abstract: A base plate includes a support part, a bottom plate part, and a wall part. The wall part includes a first wall part and a second wall part above the first wall part. The first wall part includes a first wall surface and a support surface spreading from an upper end of the first wall surface to a radially outer side. The second wall part includes a second wall surface and a recess recessed to the radially outer side from the second wall surface. The recess is defined by a space enclosed by a recess wall surface located on the radially outer side of the second wall surface and extending upward from the support surface, a recess top surface connecting from an upper end of the recess wall surface to the second wall surface, and a recess support surface facing the recess top surface in an axial direction.

Abstract: A base plate is a portion of a housing of a disk driving device having a disk rotating with a rotation axis as a center, and is a cast product. The base plate has a bottom plate part and a peripheral wall part. The bottom plate part has a rectangular shape when viewed in an axial direction. The peripheral wall part extends from an outer peripheral edge of the bottom plate part toward a side of the axial direction to surround the periphery of the bottom plate part. A metal member embedded in the peripheral wall part is provided.

Abstract: A rotor assembly includes a shaft disposed along a central axis extending vertically, a tubular magnet disposed on a radially outer surface of the shaft, a lower spacer disposed axially below the magnet and fixed to the radially outer surface of the shaft, and a tubular magnet holder fixed to a radially outer surface of the magnet via an adhesive. At least a portion of an axially lower surface of the magnet holder is in contact with an axially upper surface of the lower spacer.

Abstract: A speed reducer includes a helical gear body including helical gears, a rotating shaft, a shaft holder, and a first washer disposed around the rotating shaft between the helical gear body and the shaft holder. The helical gears are disposed coaxially, are capable of rotating around the center axis, and have the same torsion angle. The shaft holder is opposed to an axial-direction end portion of the helical gear body in an axial direction via the first washer. At least one of a radially inner end portion and a radially outer end portion of the first washer includes a washer contact surface. One of the axial-direction end portion of the helical gear body and the shaft holder includes an opposed surface opposed to the washer contact surface at least in a circumferential direction.

Abstract: A motor includes a rotor, a stator, a circuit board, and a motor case. The rotor rotates around a central axis extending vertically. The stator is opposed to the rotor in a radial direction. The circuit board extends in a direction perpendicular to the central axis. In the motor case, the rotor, the stator, and the circuit board are enclosed. The circuit board includes a connector socket and a connector plug. The connector socket is fixed to the circuit board. The connector plug is fixed to a tip end of a lead wire extending outwardly of the motor case, and is connected to the connector socket downward from above the connector socket. A ceiling section of the motor case includes a projection extending downward. A lower end of the projection is opposed in an axial direction to at least a portion of an upper surface of the connector plug.

Abstract: A turntable for storage disk drive apparatuses includes a plate member made of a ferromagnetic material and a central resin member arranged at the center of the plate member and formed by injection-molding a resin. The central resin member includes a disk guide portion provided on an upper surface thereof to guide a central hole of a disk and a plurality of gate recess portions indented upwards from a lower surface of the central resin member. The gate recess portions include ceiling surfaces positioned higher than the plate member. The ceiling surfaces include a plurality of gate cut portions formed in an injection molding process.

Abstract: A turntable for storage disk drive apparatuses includes a plate member made of a ferromagnetic material and a central resin member arranged at the center of the plate member and formed by injection-molding a resin. The central resin member includes a disk guide portion provided on an upper surface thereof to guide a central hole of a disk and a plurality of gate recess portions indented upwards from a lower surface of the central resin member. The gate recess portions include ceiling surfaces positioned higher than the plate member. The ceiling surfaces include a plurality of gate cut portions formed in an injection molding process.