Abstract: There are provided a rotating member assembly and a spindle motor including the same. The rotating member assembly includes: a shaft including an outer surface step part provided in an outer surface thereof; and a rotor hub including an insertion hole into which the shaft is inserted, the insertion hole including an inner surface step part provided in an inner surface thereof and corresponding to the outer surface step part, such that the inner surface step part and the outer surface step part are fittingly-coupled to each other.

Abstract: There are provided a rotating member assembly and a spindle motor including the same. The rotating member assembly includes: a shaft including an outer surface step part provided in an outer surface thereof; and a rotor hub including an insertion hole into which the shaft is inserted, the insertion hole including an inner surface step part provided in an inner surface thereof and corresponding to the outer surface step part, such that the inner surface step part and the outer surface step part are fittingly-coupled to each other.

Abstract: There are provided a hydrodynamic bearing assembly and a motor including the same. The hydrodynamic bearing assembly includes: a fixed member; a rotating member forming, together with the fixed member, a bearing clearance filled with a lubricating fluid and rotating relatively with respect to the fixed member; upper and lower radial dynamic pressure grooves formed in at least one of the fixed member and the rotating member forming the bearing clearance therebetween while facing each other in order to generate hydrodynamic pressure at the time of rotation of the rotating member; and an auxiliary groove formed in at least one of the fixed member and the rotating member between the upper and lower radial dynamic pressure grooves in order to pump the lubricating fluid upwardly or downwardly.

Abstract: There are provided an apparatus for clamping a disk and a motor assembly having the same. The apparatus for clamping a disk according to the present invention includes an apparatus for clamping a disk, including: a rotor case jointed with an outer peripheral surface of a shaft and rotating together with the shaft; a flange part including a disk mounting surface formed at a radial outer side of the rotor case and formed to be inclined as the disk mounting surface is toward the radial outer side; and a clamping member pressing and clamping the disk to the rotor case, wherein an inclination of the disk mounting surface of the flange part is changed depending on the position of the pressing point to the disk of the clamping member.

Abstract: Disclosed herein is a flexible printed circuit board (PCB) of a spindle motor. The flexible PCB includes a solder part, an upper reinforcing plate, a lower reinforcing plate, and a soldering part. The solder part has a through hole so that a coil extending from a stator core passes through the solder part, and has a separation part which is open or closed only in one direction along with the through hole. The upper reinforcing plate supports the upper portion of the separation part. The lower reinforcing plate supports the lower portion of the solder part, and has an elliptical through hole which partially overlaps with the through hole so that the coil passes through the lower reinforcing plate. The soldering part is formed to enable the coil to be secured to the solder part.

Abstract: Disclosed herein is a spindle motor having a fluid dynamic bearing as an oil gap formed between a rotator and a stator, wherein the stator includes a sleeve having a protruding part extending in a circumferential direction formed on the upper part thereof, the rotator includes a hub including an oil interface forming member positioned under the protruding part of the sleeve and coupled to the lower end thereof, and an oil interface of the oil gap is formed between the upper part of the oil interface forming member and the lower part of the protruding part of the sleeve.

Abstract: There is provided a motor including: a sleeve supporting a shaft and a thrust plate coupled to the shaft through oil; a hub operating together with the shaft and including a magnet coupled thereto; a base including the sleeve and a core coupled thereto, the core including a coil wound therearound; and a base cover coupled to the sleeve to thereby close a lower portion of the sleeve, wherein an interval between the sleeve and the hub is smaller than an interval between the thrust plate and the base cover in order to maintain a state of non-contact between the thrust plate and the base cover.

Abstract: There is provided a spindle motor including a stator and a rotor, including: a shaft rotatably mounted with respect to the stator; and a rotor case coupled with the shaft and including a protruding part protruded axially downwardly from a lower portion of an inner diameter part thereof, wherein the shaft is provided with an outer wall part formed to have an insertion groove opened axially upwardly into which the protruding part is inserted so as to compensate for a reduction in adhesion due to a reduction in a thickness of the rotor case.

Abstract: There are provided a motor and a recording disc driving device, which may improve a coupling structure of the motor to enable a magnet provided in a rotor to thereby double as a conventional stopper. The motor may include: a sleeve into which a shaft is rotatably inserted; a sleeve holder including a body part into which the sleeve is inserted, and a flange part protruded from an upper end portion of the body part in an outer diameter direction; a rotor case fastened to an upper end portion of the shaft, and formed such that a cylindrically shaped-rotor main wall is protruded downwardly in an axial direction to receive the flange part; a magnet fastened to a distal end of the rotor main wall so that a part of the magnet is protruded downwardly of the flange part; and a stator fastened to face the magnet, and generating an electromagnetic force.

Abstract: There are provided an apparatus for clamping a disk and a motor assembly having the same. The apparatus for clamping a disk according to the present invention includes an apparatus for clamping a disk, including: a rotor case jointed with an outer peripheral surface of a shaft and rotating together with the shaft; a flange part including a disk mounting surface formed at a radial outer side of the rotor case and formed to be inclined as the disk mounting surface is toward the radial outer side; and a clamping member pressing and clamping the disk to the rotor case, wherein an inclination of the disk mounting surface of the flange part is changed depending on the position of the pressing point to the disk of the clamping member.

Abstract: There are provided a motor and a recording disc driving device, which may improve a coupling structure of the motor to enable a magnet provided in a rotor to thereby double as a conventional stopper. The motor may include: a sleeve into which a shaft is rotatably inserted; a sleeve holder including a body part into which the sleeve is inserted, and a flange part protruded from an upper end portion of the body part in an outer diameter direction; a rotor case fastened to an upper end portion of the shaft, and formed such that a cylindrically shaped-rotor main wall is protruded downwardly in an axial direction to receive the flange part; a magnet fastened to a distal end of the rotor main wall so that a part of the magnet is protruded downwardly of the flange part; and a stator fastened to face the magnet, and generating an electromagnetic force.

Abstract: Disclosed herein is a spindle motor having a fluid dynamic bearing as an oil gap formed between a rotator and a stator, wherein the stator includes a sleeve having a protruding part extending in a circumferential direction formed on the upper part thereof, the rotator includes a hub including an oil interface forming member positioned under the protruding part of the sleeve and coupled to the lower end thereof, and an oil interface of the oil gap is formed between the upper part of the oil interface forming member and the lower part of the protruding part of the sleeve.

Abstract: Disclosed herein is a flexible printed circuit board (PCB) of a spindle motor. The flexible PCB includes a solder part, an upper reinforcing plate, a lower reinforcing plate, and a soldering part. The solder part has a through hole so that a coil extending from a stator core passes through the solder part, and has a separation part which is open or closed only in one direction along with the through hole. The upper reinforcing plate supports the upper portion of the separation part. The lower reinforcing plate supports the lower portion of the solder part, and has an elliptical through hole which partially overlaps with the through hole so that the coil passes through the lower reinforcing plate. The soldering part is formed to enable the coil to be secured to the solder part.