Abstract: A plate form housing includes a winding. A sleeve which is a bearing is provided in a bearing mounting hole formed in the housing so as to be in the central position of the winding. A shaft mounting a rotor having a magnet confronting the winding supported on the sleeve. A magnetic disk is provided at the end of the shaft. The sleeve is fixed in the bearing mounting hole of the housing by using a conductive adhesive. In this manner, discharge breakdown or destruction of the information recorded in a magnetic disk due to electric charge generated in the magnetic disk rotating at high speed is prevented.

Abstract: A plate form housing includes a winding. A sleeve which is a bearing is provided in a bearing mounting hole formed in the housing so as to be in the central position of the winding. A shaft mounting a rotor having a magnet confronting the winding supported on the sleeve. A magnetic disk is provided at the end of the shaft. The sleeve is fixed in the bearing mounting hole of the housing by using a conductive adhesive. In this manner, discharge breakdown or destruction of the information recorded in a magnetic disk due to electric charge generated in the magnetic disk rotating at high speed is prevented.

Abstract: A spindle motor includes a housing, a rotor hub section arranged rotatably with respect to the housing, a sleeve section, a shaft fit rotatably in the sleeve section, and a thrust plate mounted to the sleeve section opposite to an end surface of the shaft. A thrust dynamic pressure bearing has a dynamic pressure bearing groove formed on the thrust plate, the thrust dynamic pressure bearing including lubricating oil at a relative slide interface between the thrust plate and the end surface of the shaft. The dynamic pressure bearing groove and a circumferential portion of the thrust plate are formed by etching, and a radial dynamic pressure bearing includes lubricating oil at a peripheral interface between the shaft and the sleeve section.

Abstract: In a thin type flexible disk drive motor, in order to improve undesirable jittering of rotation, an inertia ring of larger diameter than that of the rotor frame is fixed immediately under the rotor. The inertia ring consists of a short cylinder part of the larger diameter to be fixed under the rotor frame and a flange part of the diameter not smaller than that of FG (frequency generation) magnet part. The disk drive motor also has a drive pin engaging assembly that allows a drive pin to be secured within a hub of the flexible disk while stabilizing the drive pin and after disk chucking.

Abstract: A disk driving apparatus using a dynamic pressure-type bearing device of an oil lubrication type, wherein the bearing device includes a housing main body, a sleeve part fixed to the housing main body, a rotor part relatively rotatable to the housing main body, a shaft having a spherical front end clamped to the rotor part, a bottom plate at an end face of the shaft and a thrust member interposed between the shaft and the bottom plate has a dynamic pressure radial bearing constructed by the shaft and the sleeve part and having herringbone grooves formed at either of the shaft and sleeve part, the thrust member being formed of a high polymer, and a thrust pivot bearing constructed by the thrust member set at the bottom plate secured to one side of the sleeve part and one end of the shaft.

Abstract: A small motor for use in an information-communication appratus, an audio-visual apparatus or the like, and a motor for use in a portable pager and a portable telephone or the like for generating vibrations to be transmitted to a human body, the motors being efficient, small and thin in size, and having a high degree of freedom when mounted on an apparatus. To realize the motor as described above, K pieces of (K indicating any integer greater than one) magnetic units (4a, 4b, 4c) having N and S poles magnetized alternately are mounted on a rotor in a circumferential direction, and K magnetic units are axially stacked in K stages and integrally retained on a shaft (6), and this rotor is rotatably supported on a pair of bearings (9a, 9b). Cores (1a, 1b, 1c) each have a salient pole (7a, 7b, 7c) wound around with coils (3a, 3b, 3c) in K stages so as to correspond to each of the magnetic units.

Abstract: A spindle motor includes a housing, a rotor hub section arranged rotatably with respect to the housing, a sleeve section, a shaft fit rotatably in the sleeve section, a thrust plate mounted to the sleeve section and opposite to an end surface of the shaft. A thrust dynamic pressure bearing has a dynamic pressure bearing groove formed on the thrust plate, the thrust dynamic pressure bearing including lubricating oil at a relative slide interface between the thrust plate and the end surface of the shaft. The dynamic pressure bearing groove and a circumferential portion of the thrust plate are formed by etching, and a radial dynamic pressure bearing includes lubricating oil at a peripheral interface between the shaft and the sleeve section.

Abstract: A disk driving spindle motor wherein a hub portion having a flange portion on which a disk is to be clamped is supported for rotation relative to a housing body and a rotor frame is attached to the flange portion, the hub portion being driven for rotation by magnetic repulsive action produced between the housing body and the rotor frame. A clearance extending from the outer to the inner periphery of the flange portion is formed between the abutment surfaces of the flange portion and the rotor frame. This structure results in decreased warping of a disk attached to a disk support surface.

Abstract: In a thin type flexible disk drive motor, in order to improve undesirable jittering of rotation, an inertia ring of larger diameter than that of the rotor frame is fixed immediately under the rotor. The inertia ring consists of a short cylinder part of the larger diameter to be fixed under the rotor frame and a flange part of the diameter not smaller than that of a FG (frequency generation) magnet part. The disk drive motor also has a drive pin engaging assembly that allows a drive pin to be secured within a hub of the flexible disk while stabilizing the drive pin and after disk chucking.

Abstract: In a thin type flexible disk drive motor, in order to improve undesirable jittering of rotation, an inertia ring of larger diameter than that of the rotor frame is fixed immediately under the rotor. The inertia ring consists of a short cylinder part of the larger diameter to be fixed under the rotor frame and a flange part of the diameter not smaller than that of FG (frequency generation) magnet part. The disk drive motor also has a drive pin engaging assembly that allows a drive pin to be secured within a hub of the flexible disk while stabilizing the drive pin and after disk chucking.

Abstract: A spindle motor has a tapped hole formed in the end surface of a rotor hub at the center of rotation of the rotor hub. A clamping member presses a disk against a disk holding surface of the rotor hub by a clamp screw threaded in the tapped hole. Since the disk is clamped through a clamping member by threading and tightening one clamp screw, the clamping operation is efficiently carried out and disk imbalance due to the clamping clamp screw is decreased.

Abstract: A dynamic pressure bearing spindle motor includes a housing; a sleeve fixed to the housing and having a projecting lip; a rotor hub rotatable with respect to the housing and having a stopper which is engageable with the projecting lip; a shaft fixed to the rotor hub and rotatably inserted into the sleeve; a thrust plate attached to the sleeve so as to be opposed to an end face of the shaft; and lubricating oil provided between the thrust plate and the end face of the shaft to form a thrust bearing and also provided between the shaft and the sleeve to form a radial dynamic pressure bearing.

Abstract: In order to prevent clouding of a hard disc and a polygon mirror, a tin-free electrodepositing coating composition is used as an insulating coated film of a motor for driving the hard disc and polygon mirror.