Kabushiki Kaisha Sankyo Seiki Seisakusho

Sankyo Seiki Mfg. Co., Ltd

Koichi Katakura

Yutaka Ishizuka

Shinji Kinoshita

Mitsuru Ide

Kimio Kitajima

Sadayoshi Mineta

Masaaki Satoh

A spindle motor comprises a fixed journal, a hub for loading disks, a ball bearing for rotatably supporting the hub and an annular member fixed on one of the fixed journal and the hub. The fixed annular member is configured to create to create a small space with the hub or fixed journal which is opposite the one on which the annular member is fixed. When L1 is the dimension of a space between a top surface of a top disk and a surface of a member facing said top surface of said top disk, and L2 is the dimension of a space between a bottom surface of a bottom disk and a surface of a member facing the bottom surface of the bottom disk, the annular member has grooves for generating air flow directed toward the space of longer dimension, one of said dimensions L1 and L2.

Spindle motor

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

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 current feed means is connected to an armature coil of a motor. Current is fed from the current feed means to the armature coil while the frequency of the current is gradually varied from a preset frequency to another preset frequency, thereby to vibrate the motor. The amplitudes of the frequencies are measured by a frequency analyzer means, which is brought into contact with the motor. The frequency at which the amplitude of the vibration of the motor is peaked indicates the natural frequency of the motor.

Method of measuring natural frequency of motor

A motor comprising a driving magnet attached to a rotor, a stator core which is disposed facing to the driving magnet and on which a coil is wound around each of a plurality of salient poles thereon, a motor frame securing the stator core, a first mounting section provided on the motor frame to mount the neighborhood of the base side of each salient pole, a second mounting section provided on the motor frame and formed integrally therewith to mount the edge side of each salient pole. The first mounting section and second mounting section are provided on the motor frame to mount the neighborhood of the base side and the edge side of the plurality of salient poles of the stator core, so that the motor which is able to prevent the vibration caused by a magnetic imbalance from being generated and to improve the shock resistance. Further, the motor may be more readily flattened and certain motor relationships are defined providing advantageous performance capabilities.

Driving motor

A magnetic disc drive device contains a cylindrical hub integrally rotating with a magnetic disc, the cylindrical hub having disc clamp holes defined in an end surface thereof; a motor for rotating the cylindrical hub; and a projecting member formed between the disc clamp hole and the magnetic disc to be clamped in such a manner that the projecting member is extended in the axis direction of the hub on said end surface of the hub.

Magnetic disc drive device with hub and clamper assembly for reducing

An improved armature for a small motor comprising a stator core constructed by laminating a plurality of magnetic plates having a plurality of salient poles projecting radially from a ring section, driving coils wound around coil winding sections created on the salient poles, winding slots created at positions where the salient poles adjoin each other and an insulating holder for insulating connecting sections for connecting end wires of the driving coils and lead wires from the driving coils; wherein the insulating holder comprises a plurality of insulating sections created in a manner communicating with each other in the lamination direction of the stator core to be mounted to the slots; holes penetrating through the insulating sections in the lamination direction for inserting the connecting sections and the vicinity thereof and a linking section for linking an end of each of the plurality of insulating sections. The insulating holder having a plurality of insulating sections and the linking section for linking the insulating sections are created in one body, so that a plurality of insulating sections may be created and handled as one part and the size of the insulating holder can be large, thereby facilitating its handling.

Armature of a small motor employing an insulating holder having a

A magnetic disc drive motor comprises a hub for carrying magnetic discs on its outer periphery, a drive magnet rigidly fitted to the inner periphery of the hub, a stator core having a coil wound around it and juxtaposed with the drive magnet and a motor frame having a substantially cylindrical holder for rigidly holding the stator core, wherein the space between the stator core and the motor frame is filled with a resin material. A compact and simply configured magnetic disc drive motor can thus be realized, which is capable of rotating magnetic discs in a very stabilized manner.

Magnetic disc drive motor

A motor for driving a magnetic disk in which the rotational center of the magnetic disk is a fixed shaft. The motor has a frame, a shaft formed integral with the frame, an armature, a bearing provided on the shaft, a hub to which a magnetic disk is securable, a magnetic sealing material arranged in the vicinity of the bearing and a magnetic material opposed to the sealing material. A magnetic seal is arranged between the magnetic sealing mateial and the magnetic material. The frame, the shaft, the hub and the magnetic disk are formed of aluminum, so that changes in temperature will not adversely affect motor performance due to the differences in thermal expansion of these motor parts. The magnetic material is in the form of a sleeve which enables the motor to be magnetically sealed and prevents foreign matter in the motor from reaching the magnetic disk.

Growing community of inventors

Nagano, Japan

Koichi Katakura