Kabushiki Kaisha Sankyo Seiki Seisakusho

Sankyo Seiki Mfg. Co., Ltd

Yutaka Ishizuka

Koichi Katakura

Masayoshi Saichi

Shinji Kinoshita

Shinji Ohta

Yoshinari Yoko

In a spindle motor,, a motor frame,is molded from a resin. Therefore, even if an impact is applied to a motor apparatus in which this motor,is installed, the impact can be absorbed and hence moderated by the motor frame,, and ball bearings held by the motor frame,can be prevented from being deformed. In addition, since lead terminals,for feeding an armature are insert molded in a bottom portion,of the motor frame,, there is no need to use a connector that prevents the miniaturization of the motor or an FPC board which may cause a risk of a wiring pattern being disconnected.

Spindle motor

A cylindrical yoke,bonded to an inner surface,of a cylindrical portion,of a rotor case,of a motor has a yoke separating slit,for separating the yoke,in the circumferential direction. A cylindrical rotor magnet,is partially bonded to an inner surface,of the yoke,at a plurality of bonded portions,formed apart from one another for the same intervals in the circumferential direction. When the cylindrical portion,has been expanded by heat, the yoke separating slit,is expanded and the yoke,follows the non-bonded portion of the cylindrical portion,Therefore, distortion of the cylindrical portion,can be prevented. In the non-bonded portions,between the yoke,and the rotor magnet,deformation occurs such that an inner surface,of the yoke,is separated from an outer surface,of the rotor magnet,Thus, damage of the rotor magnet,can be prevented.

Motor rotor using a cylindrical yoke with slit

A rotary polygonal mirror driving apparatus comprises a rotor to which a driving magnet is attached, a stator disposed opposite to the driving magnet, a rotary polygonal mirror having a center hole through which a portion of the rotor is mounted so that it is mounted on a mirror mounting portion of the rotor and a cap is fixed to the rotor so that the rotary polygonal mirror is pushed in a thrust direction to be fixed onto the rotor. A top annular groove and a bottom annular groove concentric with the center hole are provided, which are cut in top and bottom surfaces in a mutually overlapping area radially further out than the mirror portion of the rotor.

Rotary polygonal mirror driving apparatus

A shaft-fixed-type motor comprises a motor frame having a frame through hole formed therein, a fixed shaft having a shaft through hole at a center and fixed to the motor frame and a rotary member having a shaft hole into which the fixed shaft is inserted, and rotatably supported with respect to the fixed shaft. The motor also includes a hydrodynamic bearing mechanism arranged between an outer surface of the fixed shaft and an inner surface of the shaft hole, a rotor assembly integrally configured with the rotary member, a stator assembly installed to the motor frame and positioned opposite the rotor assembly and a joining member having a head portion and a shaft portion. The joining member is for fixing the fixed shaft to the motor frame by inserting the shaft portion into the shaft through hole of the fixed shaft and the frame through hole of the motor frame and plastically deforming an opposite end from the head portion.

Shaft-fixed-type motor

In a rotary polygon mirror type light deflector 1, since a ring-shaped polygon mirror 8 is mounted on the periphery of a bearing rotor 3, there exists a clearance between the bearing rotor 3 and polygon mirror 8. Even in this structure, if the leading end portion 110 of a fixing screw 11 is contacted with a wedge-shaped positioning member 12A within a groove 35 when the fixing screw 11 is threadedly engaged into the screw hole 35, then the positioning member 12A is allowed to push out the polygon mirror 8 toward the outer peripheral side thereof by an amount equivalent to the above-mentioned clearance, thereby being able to position and fix the polygon mirror 8 in the radial direction.

Rotary polygon mirror type light deflector

A disk driving device including a hub which rotatably supports a disk with the aid of bearings, a yoke which is fixedly secured to the hub so as to be turned together with the hub, a drive magnet unit which is fixedly mounted on the inner cylindrical surface of a cylindrical portion of the yoke, and a stator core confronted with the drive magnet unit. In the device, the yoke includes a bent portion and the hub includes a flange which protrudes below and outwardly from a disk mounting portion of the hub and which has an upper surface having an inner diameter substantially equal to an inner diameter of the bent portion of the yoke. The flange is located below a disk mounting portion, and the flange is fixedly held between the inner surface of the bent portion of the yoke and the upper end face of the drive magnet unit.

Disk driving device with hub flange secured between yoke and drive magnet

A drive magnet unit is fixedly mounted on the inner cylindrical surface of the cylindrical portion of a rotor yoke which is fixedly mounted on a hub, in such a manner that the drive magnet unit confronts a stator core. The rotor yoke has an annular portion along its open end. The rotor yoke has a curved portion along the open end which forms a gap with the outer cylindrical surface of the drive magnet unit. The annular portion is sheared along its base, thus forming a shear plane. The inner surface of the bottom of the rotor yoke, and the inner cylindrical surface of the cylindrical portion of the rotor yoke form a right-angled portion with which the right-angled outer edge portion of the drive magnet unit is engaged. The peripheral surface of the right-angled portion defines a through-hole in the bottom which is engaged with the hub. The gap is filled with adhesive, to fixedly secure the drive magnet unit to the rotor yoke.

Spindle motor, and its rotor yoke manufacturing method

In an electric motor, its motor frame has a shaft hole, a shaft is fitted in the shaft hole in such a manner that its one end potion is in the shaft hole while the other end portion is extended outside the motor frame. The motor frame includes a bearing-receiving portion extended therefrom in such a manner that the bearing-receiving portion confronts with the inner race of a rolling bearing fitted on the end portion of the shaft, and has a wall surface which merges with the wall surface of the shaft hole. The shaft has a groove which is covered by a part of the inner cylindrical surface of the inner race of the ball bearing and by the wall surface of the protruded portion. The inner raced is fixedly secured to the shaft with adhesive.

Electric motor

A blank is formed of a sintered alloy by sintering a mixture of powdered materials including powdered aluminum, and at least one of powdered silicon, powdered magnesium, and powdered chromium. This blank, being made of the sintered body, can be molded into a shape close to the final shape of a rotary polygon mirror. For example, a mirror surface can be molded into a desired shape in advance. Therefore, the final product of the rotary polygon mirror can be obtained with ease by subjecting the blank to a simple finishing process by cutting.

Rotary polygon mirror

Rotary polygon mirror type light deflecting system having a labyrinth ring fixed to an end of a fixed shaft. An outer circumferential surface of a labyrinth ring is caused to confront an inner circumferential surface of a polygon mirror while interposing a small gap therebetween in a radial direction. Further, a lower portion of a circular hole of the polygon mirror is fitted with a cylindrical sleeve of a hub to fix the polygon mirror to the hub. The polygon mirror and the labyrinth ring are made of the same material, e.g., aluminum or an aluminum alloy. The small gap is made as small as possible.

Rotary polygon mirror type light deflecting system

A rotary polygon mirror type light deflecting system including a mirror, a hub, and a fixed shaft made of materials whose coefficients of linear expansion are equal to one another. A fixed shaft is erected integrally with a frame. Inner races of ball bearings are secured to the fixed shaft. A stator has a coil wound around a stator core formed contiguously with the frame. A drive magnet annularly surrounding the outer circumferential surface of the stator core and a yoke are fixed to a polygon mirror with a clamper and screws through a hub. The drive magnet, the yoke, and the hub are secured to the fixed shaft and made rotatable by the outer races of the ball bearings secured to the fixed shaft.

A magnetic disk driving device includes a frame which supports a shaft, a hub adapted to hold a disk, and upper and lower bearings which are fitted in a bearing holding hole and rotatably support the hub. The frame includes a cylindrical protrusion which is confronted through a small gap d with the outer cylindrical surface of the outer race of the lower bearing. The small gap d forms a labyrinth in the space through which the inside of the lower bearing is communicated with the outside. The inner cylindrical surface of an annular protrusion formed on the bottom of the hub, and the inner cylindrical surface of the cylindrical protrusion are substantially equal in diameter.

Disk driving motor

A magnetic disc drive motor contains a frame; a fixed shaft mounted on the frame and provided with two circumferential grooves; a bearing member including: a plurality of balls disposed in the circumferential grooves; upper and lower roller rings mounted on the fixed shaft through the halls disposed in the circumferential grooves; a pre-loading spring mounted between the upper and lower roller rings; a rotor fixed to one end of the lower roller ring and provided with a loading surface formed in its upper surface; and a motor member mounted below the rotor, wherein the upper and lower roller rings are exposed above the upper surface of the rotor, the roller rings are fitted in center holes of magnetic discs, and inner peripheral portions of the magnetic discs are loaded on a loading surface of the rotor.

Magnetic disk drive motor having a fixed shaft with circumferential

A magnetic disc drive motor contains a frame; a fixed shaft mounted on the frame; a ball bearing for rotatably supporting a magnetic disc by fitting an inner center hole of the magnetic disc on an outer ring of the ball bearing, an inner ring of the magnetic disc being secured to the fixed shaft; a rotor fixed to one end of the ball bearing, the rotor having a loading surface defined on an upper surface thereof; and a motor member including: a rotor member mounted in an inside of the rotor; and a stator member secured on the frame, wherein the inner peripheral portion of the magnetic disc fitted on the outer ring of the ball bearing is mounted on the loading surface of the rotor.

Magnetic disk drive motor including a fixed shaft having mounted thereon

A magnetic disc drive motor contains a frame; a fixed shaft mounted on the frame; a lower bearing member mounted on a lower portion of the fixed shaft, the lower bearing member being provided with a roller ring rotating about the fixed shaft, the lower bearing member being provided with a loading portion defined at one end of the roller ring; an upper bearing member mounted on the upper portion of the fixed shaft, the upper bearing member being provided with a cylindrical roller ring; and a motor including: a rotor fixed under a loading surface portion of the loading portion of the lower bearing member; and a stator disposed inside the rotor and fixed to a frame, wherein each of the roller rings is fitted in the center hole of a magnetic disc and an inner peripheral portion of the magnetic discs are loaded on the loading portion.

Growing community of inventors

Nagano, Japan

Yutaka Ishizuka