JPH0266782A - Actuator mechanism for magnetic disk device - Google Patents

Abstract

PURPOSE:To prevent the dislocation of a magnetic head for a disk track by manufacturing respective constituting components such as a shaft, a bearing and a head supporting body with materials having approximately the same thermal expansion coefficient. CONSTITUTION:The components constituting an actuator mechanism such as a carriage shaft 11, radial bearings 14 and 15, an arm supporting block 13, and a head arm 16 are manufactured by the same types of the materials having functionally sufficient strength and rigidity, and the material light and excellent for durability, or the material having approximately the same thermal expansion coefficient. Consequently, the distortion and deformation between the respective constituting components at the time of rising temperature can be prevented, the dislocation of the magnetic heads for the disk track can be prevented, and device performance can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an actuator mechanism for a magnetic disk device that performs a positioning operation of a magnetic head with respect to a magnetic disk.

(Prior Art) Conventionally, a rotary carriage system has been widely used as an actuator mechanism for positioning a magnetic head in a magnetic disk device.

FIG. 2 is a sectional view showing this actuator mechanism.

In the figure, ] is a carriage shaft fixed vertically on carriage base 2, and 3 is a carriage shaft]
An arm support block 6 is externally fitted and held rotatably within a predetermined angle range via two upper and lower radial bearings 4.5, and 6 is a plurality of helad arms provided integrally with the arm support block 3. A magnetic head (not shown) for reading/writing data from/to a magnetic disk is supported at the tip of each helad arm 6.

Further, 7 is a thrust preload spring which is fitted onto the carriage shaft 1 and applies an upward preload in the thrust direction to the outer ring 4a of the radial bearing 4 (on the upper side in the figure) to eliminate the radial gap within the radial bearing 4; Reference numeral 8 denotes a radial preload spring for applying a radial preload to the radial bearing 4 which has received preload from the thrust direction.

In each of these components, steel is used for the carriage shaft 1 and radial bearing 4.5, as they each require high structural strength, while the arm support block 3 and head arm 6 are made of aluminum. Structural light metals such as alloys and magnesium alloys are used.

By the way, in such an actuator mechanism, since the coefficient of thermal expansion of the carriage shaft 1 is larger than that of the arm support block 3, the outer ring 5a of the radial bearing 5 on one side (lower in the figure) is attached to the arm support block 3 with adhesive or the like. In contrast, the outer ring 4a of the other (upper part in the figure) radial bearing 4 is attached to the arm support block to prevent distortion and deformation between the carriage shaft 1 and the arm support block 3 due to the difference in coefficient of thermal expansion. 3 is fitted with a gap. The radial bearing 4 is pressed against the carriage shaft 1 so as to maintain a constant posture by a radial preload spring 8 whose one end is fixed inside the arm support block 3.

However, in this actuator mechanism, due to the difference in thermal expansion coefficient between the radial bearing 4.5 and the arm support block 3, the center position of the radial bearing 4.5 and the center position of the arm support block 3 may shift when the temperature rises. As a result, there is a possibility that the magnetic head may be misaligned with respect to the track of the magnetic disk.

Furthermore, distortion and deformation occur between the arm support block 3 and the outer ring 5a of the radial bearing 5 fixed thereto, which also causes a problem in that the position of the magnetic head is shifted.

(Problems to be Solved by the Invention) The present invention is intended to solve the problems in the actuator mechanism of conventional magnetic disk drives, and by reducing the number of parts, it prevents distortion and deformation between each component when the temperature rises. An object of the present invention is to provide an actuator mechanism for a magnetic disk device, which can prevent misalignment of a magnetic head with respect to a disk track, thereby significantly improving device performance.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the actuator mechanism of the magnetic disk drive of the present invention includes a fixed shaft and a rotatably fitted external shaft to the shaft via a bearing. In an actuator mechanism for a magnetic disk device, the shaft, the bearing, and the head support are each arranged at substantially equal positions. It is manufactured using a material with a high coefficient of thermal expansion.

(Function) In the actuator mechanism of the magnetic disk device of the present invention,
Since the shaft, bearing, and head support are each made of materials with approximately the same coefficient of thermal expansion, there is no distortion or deformation between the components at elevated temperatures.

Therefore, in conventional actuator mechanisms, since the thermal expansion coefficients of the bearing and the head support are different, the bearing is fitted into the head support with a gap in order to prevent distortion and deformation when the temperature rises between them. was, but
The present invention eliminates that need.

As a result, accessory parts such as a thrust preload spring that preloads the bearing in the thrust direction and a radial preload spring that maintains a constant attitude of the bearing relative to the shaft can be omitted, and the number of parts can be reduced.

Furthermore, it is possible to prevent the magnetic head from being misaligned with respect to the tracks of the magnetic disk, and it is possible to significantly improve the performance of the device.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a sectional view for explaining an actuator mechanism of a magnetic disk device according to an embodiment of the present invention.

In the figure, 11 is a carriage shaft vertically fixed on a carriage base 12, and 13 is an arm externally held on the carriage shaft 11 via two radial bearings 14 (upper and lower), and 5 so as to be rotatable within a predetermined angle range. The support block 16 is a plurality of head arms provided integrally with the AM support block 13, and each of the head arms 16 has a magnetic head (see Fig. (not shown) is supported.

Among the parts constituting this actuator mechanism, the carriage shaft 11, radial bearing] 4.15, arm support block 13, and head arm 16 each have sufficient functional strength and rigidity, and are lightweight and durable. made of different materials or materials with approximately the same coefficient of thermal expansion. In addition, when using the same material, it is desirable to use, for example, a fine ceramic represented by silicon nitride.

Therefore, the actuator mechanism of this embodiment can prevent distortion and deformation between the components when the temperature rises.

Zuna 4cchi, conventionally, carriage shaft] 1
Since the coefficients of thermal expansion are different between the outer ring 14a of the radial bearing 14 and the arm support block 13, the outer ring 14a of the radial bearing 14 is attached to the arm support block 1 in order to prevent distortion and deformation during the temperature rise.
3 was inserted with a gap. However, in this actuator mechanism, the outer ring 1.4 a of the radial bearing 14
There is no need to create a gap between the arm support block 13 and the arm support block 13, and it is sufficient to simply fix the two with adhesive or the like, and as a result, the use of additional parts such as radial preload springs and thrust preload springs can be omitted. becomes possible.

Furthermore, since it is possible to prevent the center position of the arm support block 13 and the center position of the radial bearings 14, ]5 from shifting when the temperature rises, it is possible to prevent the positional shift of the magnetic head relative to the track of the magnetic disk. , it becomes possible to significantly improve the performance of the magnetic disk device, such as improving the track density, which had been limited due to positional deviation with respect to the track.

It goes without saying that the arm support block and the plurality of helad arms in the embodiments described above may be a so-called head support body manufactured by integrally molding image component parts.

[Effects of the Invention] As explained above, according to the actuator mechanism of the magnetic disk drive of the present invention, distortion and deformation between each component when the temperature rises can be prevented with a smaller number of parts, and thereby It is possible to prevent misalignment of the magnetic head and to significantly improve device performance.

[Brief explanation of the drawing]

FIG. 1 is a sectional view illustrating an actuator mechanism of a magnetic disk drive according to an embodiment of the present invention, and FIG. 2 is a sectional view illustrating an actuator mechanism of a conventional magnetic disk drive. 11... Carriage shaft, 12... Carriage base, 13... Arm support block, 14.15... Radial bearing, 16... Head arm. Applicant: Toshiba Corporation

Claims (1)

[Claims] (1) A fixed shaft, and a head support that is rotatably fitted onto the shaft via a bearing and supports a plurality of magnetic heads at a predetermined distance from the center of the shaft. 1. An actuator mechanism for a magnetic disk drive comprising: the shaft, the bearing, and the head support body each made of a material having substantially the same coefficient of thermal expansion.