JPH0817011B2 - Positioning mechanism for swing arm of magnetic disk device - Google Patents

Description

The present invention relates to a positioning mechanism for a swing arm of a magnetic disk device.

[Conventional technology]

Generally, FIG. 2 shows a magnetic disk device having a swinging arm positioning mechanism. In FIG. 2, the arm 1 has a magnetic head (not shown), and swings around the central axis 2 via a bearing 6. The coil 5 is installed in the magnetic circuit 4 integrally with the arm 1. The upper substrate 3a and the lower substrate 3b support the central axis 2 and the magnetic circuit 4. Therefore, when a current is applied to the coil 5, the arm 1 swings around the central axis 2 via the bearing 6 by the magnetic field of the permanent magnet provided in the magnetic circuit 4, and the magnetic head (magnetic disk) (Not shown) is positioned at a predetermined position.

Here, since the inner ring 6a (see FIG. 3) of the bearing 6 necessarily has a slight gap with respect to the center shaft 2, if it is left as it is, backlash occurs between the inner ring 6a and the center shaft 2. However, the above positioning accuracy becomes poor.

Therefore, conventionally, as shown in FIGS. 2 and 3, a hole 2a perpendicular to the shaft is provided at a height position corresponding to the bearing 6 of the central shaft 2,
The spacer 7 and the coil spring 8 are housed, and the coil spring 8 urges the spacer 7 in the radial direction against the inner ring 6a to apply a load in the radial direction, and the reaction force relatively moves a part of the central shaft 2 to the inner ring.
Press against 6a. Thereby, the inner ring 6a is supported at two points to remove the play between the inner ring 6a and the central shaft 2, thereby coping with the positioning accuracy.

[Problems to be solved]

In the conventional rocking arm positioning mechanism of the magnetic disk device described above, the structure in which the gap between the central shaft 2 and the inner ring 6a of the bearing 6 is fixed at two points does not support the arm 1 in the rocking direction. Since it is structurally unstable, there is a problem in that a frequency component of vibration due to structural instability appears in the rocking direction and good rocking characteristics cannot be obtained.

[Means for solving problems]

The present invention has solved the above-mentioned problems, and a bearing that rotates an arm group having a plurality of magnetic heads mounted thereon, a central shaft that supports the bearing, and a central shaft that is provided on the central shaft and urges a spacer. A spring means for press-contacting a predetermined portion of the inner ring of the bearing to apply a radial load and relatively press-contact to a portion of the center shaft substantially opposite to the predetermined portion of the inner ring of the bearing, and integrally assembled to the arm group. Of a swing arm of a magnetic disk device including a coil attached thereto, a magnetic circuit having a permanent magnet that repels a magnetic field generated in the coil, and an upper substrate and a lower substrate that support the central axis and the magnetic circuit. In the positioning mechanism, a notch portion is provided on the center shaft on the side opposite to the urging direction of the spring means and at a position corresponding to the bearing, and a surface forming the notch portion has a center line of the center axis. Including It is made of formed parallel to the one plane.

〔Example〕

 Next, the embodiment will be described with reference to FIG.

FIG. 1 is a cross-sectional view showing an embodiment of a positioning mechanism for a swing arm of a magnetic disk device according to the present invention, in which the same parts as those in FIG. 3 are designated by the same reference numerals.

In FIG. 1, in the present embodiment, a hole 2a perpendicular to the axis of the central axis 2 is formed.
At a position opposite to the bearing 6 and at a position corresponding to the bearing 6.
Of the inner ring 6a is provided with a notch 2b (reference is shown by a chain double-dashed line in FIG. 2) having a length greater than that of the inner ring 6a, and the surface forming the notch 2b includes the center line of the central axis 2. It is formed parallel to one of the faces.

According to this, the spacer 7 is attached to the inner ring by the coil spring 8.
When the core shaft 2 is urged against the inner ring 6a by the reaction force, the center shaft 2 is relatively pressed against the inner ring 6a, but actually both ends of the notch 2b are pressed against the inner ring 6a. Therefore, as a whole, the spacer
7. The arm 1 is stably positioned by supporting three points on both ends of the notch 2b. Therefore, the arm 1 is structurally stable, and good vibration characteristics can be obtained.

The notch 2b may be provided not only in the upper bearing 6 but also in the lower bearing 6.

〔The invention's effect〕

As described above, according to the present invention, the bearing portion on the central shaft is provided with the cutout portion at a portion corresponding to the bearing of the central shaft, and the surface forming the cutout portion is a surface including the center line of the central shaft. When the radial load is applied to the inner ring of the bearing through the spacer by the coil spring housed in the hole perpendicular to the axis on the central axis, the central axis and the inner ring of the bearing are at three points. Since it is supported, it has the effect of being structurally stable and having good vibration characteristics. Moreover, the flat surface of the notch makes it easy to process, and it is also easy to accurately position the support. There is an effect.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a positioning mechanism of a swing arm of a magnetic disk device according to the present invention, FIG. 2 and FIG.
FIG. 1 is a vertical cross-sectional view of a magnetic disk device to which an example of a positioning mechanism for a swing arm of a conventional magnetic disk device is applied,
FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 1 ... Arm, 2 ... Center axis 2a ... Hole at right angles to axis, 2b ... Notch 3a ... Upper substrate, 3b ... Lower substrate 4 ... Magnetic circuit, 5 ... Coil 6 ... Bearing, 7 …… Spacer 8 …… Coil spring

Claims (1)

[Claims] 1. A bearing for rotating an arm group having a plurality of magnetic heads mounted thereon, a central shaft for supporting the bearing, and a central shaft provided on the central shaft for biasing a spacer to a predetermined portion of an inner ring of the bearing. Spring means for pressing and applying a radial load to relatively press a portion of the center shaft substantially opposite to a predetermined portion of the inner ring of the bearing; a coil integrally assembled to the arm group; In a positioning mechanism of a swing arm of a magnetic disk device, which comprises a magnetic circuit having a permanent magnet that creates a repulsive action with a magnetic field generated in the central axis, and an upper substrate and a lower substrate supporting the central axis and On the side opposite to the urging direction of the spring means and at a position corresponding to the bearing, and the surface forming the notch is parallel to one of the surfaces including the center line of the central axis. Formed Positioning mechanism of the swing arm of the magnetic disk apparatus according to claim Rukoto.