JPS63311675A - Rotary actuator for information recording and reproducing device - Google Patents

Abstract

PURPOSE:To improve the positioning accuracy of plural heads on an information recording medium by fixing an end of a support shaft to an actuator housing through a support member made of a material having a different thermal expansion coefficient from that of the actuator housing. CONSTITUTION:Suppose that a deformation causing a tilt approaching the turning center axis A of a magnetic disk 6 at a side remote from a base 5 of an actuator housing 1 is caused at a high temperature from a low temperature, the thermal expansion of the material of a flange member 22 is selected to be larger than the thermal expansion rate of the material of the actuator housing 1 and the flange is fixed only at a part P. Thus, the flange member 22 is expanded around the part P with respect to the actuator housing 1 by a temperature change at a high temperature from a low temperature and the end of the flange member 22 of the center axis B of the support shaft 2 is parted from the turning center axis A of a magnetic disk 6, then the turning center axis B of the actuator arm 3 is moved in a direction in parallel with the magnetic disk turning center axis A. Thus, the tilt of the support shaft 2 due to temperature change is corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotary actuator for an information recording/reproducing device, and particularly relates to a mounting structure for a support shaft serving as a center of rotation of an actuator arm and a seven-piece unit housing.

[Conventional technology]

FIG. 4 is a diagram showing the structure of a conventional rotary actuator for a magnetic disk drive disclosed in, for example, Japanese Utility Model Application Publication No. 61-101851. In the figure, (1) is the actuator housing, (2) is the support shaft, (3) is the actuator arm, and (4) is this actuator arm (3).
This is a bearing that supports the shaft.

(5) is a base, (6) is a magnetic disk as an information recording medium, and (7) is a magnetic head. The magnetic disk (6) is supported by a spindle (not shown),
Rotate.

Next, the operation will be explained. Information is written and read on the magnetic disk (6) by a magnetic head (7) in a magnetic disk device, but the writing and reading positions are determined by an actuator drive mechanism (not shown) with the actuator arm (3) as the rotation center. It is determined by rotating the magnetic head (7) around the supporting shaft (2) and positioning the magnetic head (7). The actuator arm (3) has a bearing (
4) and the support shaft (2) through the actuator housing (1).
) is rotatably supported on the actuator housing (
1) is attached to the base (5). The center axis of rotation of the actuator arm (3) is the center axis B of the support shaft (2).
, and these central axes B coincide with the magnetic disk (
6) is parallel to the rotation center axis A. Multiple magnetic heads (
7) is usually fixedly attached to the actuator arm (3), so positioning of the plurality of magnetic heads (7) is possible by positioning a specific magnetic head. As long as the rotation center axis B of the arm (3) and the rotation center diameter of the magnetic disk (6) are parallel υ, the position of the positioned magnetic head will not shift even if the positioning operation is repeated. do not have.

[Problem that the invention seeks to solve]

A conventional rotary actuator for an information recording/reproducing device is constructed as described above, and the actuator housing (1) needs to be fixed to the base (5). However, the materials of the actuator housing (1) and the base (5) If the rotation center axis B of the actuator arm is different from that of the magnetic disk, the base (5) of the mounting part of the actuator housing (1) is deformed due to the temperature change, and the rotation center axis B of the actuator arm and the narrow center of rotation of the magnetic disk are parallel to each other, as shown in Fig. Even if a specific magnetic head is used to position the disk, other magnetic heads may be misaligned, making it difficult to write information at a predetermined position on the magnetic disk.
There were problems such as readout being impossible.

This invention was made in order to solve the above-mentioned problems, and it is possible to keep the rotation center axis of the actuator arm and the rotation center axis of the information recording medium parallel at all times even if the temperature changes in the device. An object of the present invention is to provide a rotary actuator for an information recording/reproducing device in which when a specific head is positioned, a plurality of other heads are positioned at predetermined positions.

[Means for solving problems]

The rotary actuator for an information recording/reproducing device according to the present invention is fixed to an actuator housing at least one end of a support shaft, which is made of a material having a coefficient of thermal expansion different from that of the actuator housing.

[Effect]

The rotary actuator for an information recording/reproducing device according to the present invention has one end of the support shaft fixed to the actuator housing via a support member made of a material with a different coefficient of thermal expansion from that of the actuator housing. The support member corrects the inclination.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In Fig. 1, (1) is an actuator housing;
(2) is a support shaft, and (22) is a support member made of a material with a coefficient of thermal expansion different from that of the housing (1), interposed between one end of this support shaft (2) and the housing (1). The flange member (3) is an actuator (6) which is a magnetic disk, and (7) is a magnetic head.

The positioning operation of the magnetic head (7) for writing and reading information in a magnetic disk device is no different from the conventional one.

If a temperature change occurs in the magnetic disk drive, the base of the actuator housing (1) (
5), the actuator housing (1) is deformed and the actuator housing (1) is tilted with respect to the central axis A of rotation of the magnetic disk. In this embodiment, the actuator housing (1) K is attached via a 2-rank member (22) provided at one end of the support shaft I (2) z. Assuming that the deformation in which the actuator housing (1) is tilted closer to the rotation center axis A of the magnetic disk (6) on the side far from the base (5) shown in Fig. 2 occurs when the temperature becomes higher than the low temperature, the rank is 7. If the material of the member (22) is selected to have a coefficient of thermal expansion larger than that of the material of the actuator housing (1) and is fixed only with the P part shown in Fig. 2, the temperature change from low to high temperature will result in 7. The rank member (22) is P relative to the actuator housing (1).
The actuator arm (
3) The rotation center axis B moves in a direction parallel to the magnetic disk rotation center axis A. In this way, 7 rank members (22
) and the material of the actuator housing (1), and by selecting the part of the flange member (22) to be fixed to the actuator housing (1), the actuator housing (1) and base (5) can be fixed. Even if the actuator housing (1) is tilted due to
The inclination of the support shaft (2) can be made small, or the rotation center axis B of the actuator arm (3) can always be kept parallel to the narrow rotation center of the magnetic disk (6).

In the above embodiment, the material of the flange member (22) has a coefficient of thermal expansion larger than that of the material of the actuator housing (1), but conversely, a material with a smaller coefficient of thermal expansion is used, The fixed part P of the rank member (22) is connected to the support shaft (
It goes without saying that the same applies to the opposite side of 2). In addition, as shown in FIG. 3, flange members (22) and (32
) is also possible. When the flange members (22) and (32) are provided at both ends of the support shaft (2) in this way, the material of the two 7-rank members and the fixation of the two flange members to the actuator housing (1) By appropriately selecting and determining the portion, the range in which the direction and magnitude of the inclination of the rotation center axis B of the actuator arm (3) with respect to the shear actuator housing (1) can be adjusted becomes large.

In addition, although a 7-rank member is used as the support member, it may be of other shapes as well.

By the way, in the above embodiment, the case where the present invention is applied to a magnetic disk device has been described, but it is not necessarily limited to this, and it goes without saying that other information recording and reproducing devices may be used. 4) fx.

〔Effect of the invention〕

As described above, according to the present invention, the actuator housing, which is at least one end of the support shaft that is the center of rotation of the actuator arm of the rotary actuator, is connected to the actuator housing via a support member made of a material with a different coefficient of thermal expansion from the actuator housing. Since I configured it to be fixed to
Even if a temperature change occurs in the information recording/reproducing device, it is possible to keep the rotation center axis of the actuator arm parallel to the rotation center axis of the information recording medium, improving the positioning accuracy of multiple heads on the information recording medium. effective.

[Brief explanation of drawings]

FIG. 1 is a side view showing the main parts of a rotary actuator for an information recording/reproducing device according to an embodiment of the present invention when used in a magnetic disk device, and FIG. 2 shows a temperature change caused in the magnetic disk device of FIG. 3 is a side view schematically showing the main parts of another embodiment, FIG. 4 is a side view showing the conventional device, and FIG. 5 is the conventional device shown in FIG. 4. FIG. 3 is a side view schematically showing a state when a temperature change occurs. In the figure, (1) is an actuator housing, (2) is a support shaft, (3) is an actuator arm, (6) is a magnetic disk as an information recording medium, and (22) is a flange member as a support member. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Zeng Wado Teru ′ −・・−・・−
Two--? 1 10 2nd prisoner Fig. 3 32 Flange Fig. 4 Fig. 5

Claims (4)

[Claims] (1) An information recording medium that is equipped with an actuator arm that supports a head for recording or reproducing information, a support shaft that supports this actuator arm, and an actuator housing that fixes both ends of this support shaft. A rotary actuator for an information recording/reproducing device, wherein at least one end of the support shaft is fixed to the actuator housing via a support member made of a material having a coefficient of thermal expansion different from that of the actuator housing. (2) The rotary actuator for an information recording/reproducing device according to claim 1, wherein the supporting members are flange members respectively interposed at both ends of the support shaft. (3) The rotary actuator for an information recording/reproducing device according to claim 2, wherein the two flange members have different coefficients of thermal expansion. (4) The rotary actuator for an information recording/reproducing device according to claim 2 or 3, wherein the flange member is fixed to the actuator housing at one point in the circumferential direction.