JP2646269B2 - Disk drive - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive for rotating a disk-shaped recording medium such as a floppy disk.

[Prior Art] FIG. 4 shows a conventional floppy disk drive (hereinafter referred to as FD).
D) is a side sectional view showing a schematic configuration of a main part, 1 is a chassis made of an aluminum die-cast or press as a main body base, 2 is a medium on which information is recorded / reproduced, and 23, 23 '. Denotes a bearing, which supports a spindle 5 that performs a medium holding drive. The medium 2 is fixed to the spindle 25 by a clamp mechanism (not shown). Reference numeral 26 denotes a rotor which holds the drive magnet 7 fixedly inside.

8 is a printed circuit board (PC) for a disk drive motor
B). Reference numeral 29 denotes a drive coil, which is arranged at predetermined intervals in a plane and applies a rotational force to the drive magnet 7 by utilizing an electromagnetic conversion force by a known current switching method. A stator yoke 10 forms a closed magnetic path with the drive magnet 7.
Reference numeral 11 denotes a magnetic head for recording / reproducing information on / from the medium 2, which is fixed to a head carriage (not shown) and is movable in the direction of the arrow in the figure.

22 is a set screw for fixing the rotor 26 and the spindle 25, 13
Is a housing for holding and fixing the bearings 23, 23 ', which is fixed to the chassis 1.

[Problem to be Solved by the Invention] However, the above-described conventional example has the following problems.

Since the thickness of the bearing portion is configured to overlap the spindle, the bearing, and the rotor, there is a limit in reducing the thickness.

The thickness of the magnetic head is accumulated on the thickness of the motor portion, and there is a limit in reducing the thickness obtained by adding the thickness of the magnetic head and the thickness of the motor by any method.

The present invention has been made to solve such a conventional problem, and the thickness of the magnetic head and the motor can be absorbed by other portions to reduce the thickness of the entire device and reduce the rotational accuracy. It is an object of the present invention to provide a disk drive device that does not cause the disk drive to run.

Means for Solving the Problems In order to achieve the above object, a disk drive device according to the present invention has a recess formed in a stator yoke at a portion corresponding to a moving portion of a head, and a magnetizing pole of a drive magnet. Assuming that the number is P and the number of drive coils is 3n, P = 4n +
By adopting No. 2, the drive coil in a portion corresponding to the concave portion of the stator yoke is removed.

[Operation] In the present invention, a concave portion is formed in the stator yoke, in which the magnetic head is inserted, the thickness can be reduced by that amount, and the number of drive coils is 3n (n = 1, 2,...) Because of three phases. When the number of poles of the drive magnet is P = 4n + 2, the two poles of the drive coil corresponding to the concave portion can be formed into a gap without lowering the rotational performance, and the concave portion of the stator yoke can be inserted there, thereby enabling a reduction in thickness. become.

FIG. 1 is a side sectional view showing an embodiment of a disk drive device according to the present invention, FIG. 2 is a diagram showing a magnetized state of a drive magnet, and FIG. 3 is an arrangement diagram of a drive coil. .

In FIG. 1, the same reference numerals as those in FIG. 4 denote the same or corresponding parts, and a description thereof will be omitted. However, if different from FIG. 4, the bearing 3 is a large-diameter radial bearing and a spindle 5 is fixed. Reference numeral 4 denotes a retaining ring, which is fixed to the chassis 1 with a clamper (not shown). The rotor 6 is fixed to the spindle 5 with a stop screw 12. Therefore, by the attraction force of the driving magnet 7,
The rotor 6 receives a force in the upward direction, and preloads and stabilizes the bearing 3 with the attraction force. Reference numeral 10 denotes a stator yoke, which is fixed to the chassis 1 by bonding, screwing, or the like. The portion where the magnetic head 11 is inserted is narrowed to form the recess 10a of the stator yoke 10. Although there is no space in the recess 10a, as shown in FIG.
Assuming that there are 14 poles (4 × 3 + 2), as shown in FIG. 3, the number of drive coils is nine, and a portion corresponding to two poles can be a space. Can be As a result, driving can be performed according to the well-known three-phase full-wave driving method.

[Effects of the Invention] As described above, according to the present invention, in a disk mounting apparatus using a surface-facing type spindle motor, a recess is formed in a stator yoke of a moving portion of a magnetic head, thereby reducing the thickness of the portion. Can be thin.

Also, for three phases, the number of magnetizations is 3
By setting 4n + 2, a gap can be formed in a portion corresponding to the two poles without lowering the rotation performance, and the recess of the stator yoke can be fitted therein, and the thickness can be reduced.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing one embodiment of a disk drive device of the present invention, FIG. 2 is a view showing a magnetized state of a drive magnet,
FIG. 3 is a layout diagram of drive coils, and FIG. 4 is a side sectional view showing a schematic configuration of a main part of a conventional floppy disk drive. In the figure: 1: Chassis, 2: Media 3: Bearing 4: Retaining ring, 5: Spindle 6: Rotor, 7: Drive magnet 8: PCB, 8a: Opening 9: Drive coil, 10: Stator yoke 10a : Recess, 11: magnetic head 12: set screw, 13: housing

Claims (1)

(57) [Claims] 1. A disk drive device equipped with a face-to-face spindle motor, wherein a concave portion is formed in a portion of a stator yoke corresponding to a portion where a head faces, and the number of magnetized poles of a drive magnet is P; A disk drive device wherein the number of drive coils in a portion corresponding to the concave portion of the stator yoke is eliminated by setting P = 4n + 2, where 3n is the number.