Abstract: A spindle motor comprising a bracket, a shaft member provided on the bracket, a rotor rotatably mounted to the shaft member through a pair of bearings, a rotor magnet mounted to the rotors, a stator disposed in opposite relation to the rotor magnet, and magnetic fluid sealing means respectively disposed outwardly of a pair of the bearings. The shaft member is provided with an air passage extending in the axial direction, and a communication passage for communicating the air passage with a space between a pair of the bearings. A cap member which is improved in its structure is disposed outwardly of one of the paired bearings. An annular projection for positioning the rotor magnet concentrically with respect to the rotor is provided on a magnet mount portion of the rotor.

Abstract: A recording disk driving apparatus comprising a base plate, a cover member defining a disk chamber in cooperation with the base plate, a spindle motor disposed in the disk chamber, and a recording disk to be rotated and driven by the spindle motor. The base plate has a first convex portion projecting greatly inwardly and a second convex portion projecting greatly inwardly, and in correspondence to the first convex portion, a receiving concave portion for accommodating electronic components is provided in its back surface. Furthermore, a raising preventing member is provided to prevent the raising of the drawing portion of the flexible circuit board for supplying an electric current to the spindle motor.

Abstract: A spindle motor comprises a stationary member, a hub for rotation relative to the stationary member, bearings provided between the stationary member and the hub, and a labyrinth seal provided outside one of the bearings. In particular, the labyrinth seal includes a plurality of labyrinth units. Each labyrinth unit is consisted mainly of a first member mounted to the stationary member and a second member mounted to the hub.

Abstract: A disk drive apparatus includes a magnetic disk, a spindle motor for rotating the magnetic disk, a magnetic head for writing data on and/or reading out data from the magnetic disk, a support arm for supporting the magnetic head, and a voice coil motor for pivoting the support arm. The spindle motor has a hub on which the magnetic disk is mounted, a rotor magnet mounted on the hub, and a stator disposed opposite to the rotor magnet. The stator includes a stator core around which an armature coil is wound. Teeth portions of the stator core are disposed substantially equiangularly in a circumferential direction while at least part of a plurality of coil winding portions are disposed non-uniformly in the circumferential direction, whereby the armature coils wound around the plurality of coil winding portions are retracted from a path in which the support arm is moved.

Abstract: A spindle motor includes a shaft, a hub assembly unit rotatable relative to the shaft, an upper bearing structure and a lower bearing structure both interposed between the shaft and the hub assembly unit, and a stator disposed between the upper and lower bearing structures. The stator, the hub assembly unit, and the upper and lower bearing structures are attached to a specific side of the shaft. The hub assembly unit has an aluminum-made hub and an iron-made yoke, both of which are joined together through a pair of fixing portions. One fixing portion has a relatively strong fitting force, whereas the other fixing portion has a relatively weak fitting force.

Abstract: An electronic wristwatch wherein a timing rate adjustment signal, representative of the amount of timing rate adjustment being effected and/or needed to be effected, is depicted. The electronic wristwatch includes a divider circuit for receiving a high frequency time standard signal from a quartz crystal oscillator circuit and for producing a low frequency timekeeping signal in response thereto. An adjustment circuit is coupled to the divider circuit for adjusting the frequency of the timekeeping signal by a predetermined amount. A converter circuit is adapted to be selectively coupled to the divider circuit to receive the adjusted low frequency timekeeping signal and, in response thereto, to produce a timing rate adjustment signal representative of the amount of adjustment applied in the low frequency timekeeping signal, and to produce a signal representative of the unadjusted oscillator frequency.