JPH01316518A - Bearing for magnetic head positioning device - Google Patents

Abstract

PURPOSE:To prevent the generation of oil mist by providing an internal ring fixed to a shaft and an external ring on which are wound a plurality of balls in a grease coated holder and holding shield plates at both ends thereof and making the gap between a plurality of balls and the shield plate such that the gap on a grease charging side becomes larger than that of an opposite side. CONSTITUTION:A holder 15 for holding a plurality of balls 14 is positioned deflected by to one side from the central part of a bearing inner ring 12 and an outer ring 13. The gaps between a plurality of balls 14 and shield plates 16a, 16b disposed at both the ends of the outer ring 13 are made larger in the gap between the ball 14 and the shield plate 16b and the grease is charged from the shield plate 16b side. Thereby, even when the bearing rotates according to the travel of a magnetic head positioning device, since the gap 18 between the charged grease 17 and the shield plate 16b is fully secured, the generation of oil mist due to the contact of the grease 17 and the shield plate 16b can be prevented.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a bearing for a magnetic disk device, and in particular to a bearing for a magnetic disk device, in which a magnetic disk and a magnetic head are housed in a sealed container, and the magnetic head is positioned on a predetermined track of the magnetic disk. The present invention relates to a bearing for a magnetic head positioning device.

[Conventional technology]

A so-called sealed magnetic disk device, in which a magnetic head and a magnetic disk are housed in a sealed container to record and reproduce information, is free from dust floating in the sealed container (this is referred to as a disk enclosure, abbreviated as DB). The airflow generated by the rotation of the magnetic disk is circulated to prevent the magnetic disk from entering the minute gap between the magnetic head and the magnetic disk and causing damage to the magnetic disk or magnetic head (this is called a head crash). Usually, an air filter device is installed in the air circulation path to remove dust from the DB.

FIG. 3 is a perspective view showing an example of a magnetic disk device of the above-mentioned sealed magnetic disk device having a so-called linear positioning device that linearly drives a magnetic head to perform a positioning operation, with the cover removed. (In addition to the above-mentioned linear type, there is also a rotary type that performs positioning by rotational movement around a fixed rotating shaft.) In particular, it is a view showing the inside of the magnetic head positioning device. It is a figure which also showed an exploded perspective view of the main part.

In FIG. 3, a magnetic head 3, which is positioned on a designated track of a magnetic disk 2 rotated by a spindle motor and used to write and read information, is mounted on a mounting plate 7. Two bearings 8 are provided on the left and right sides of the front end and the rear end of the guide shaft 6, respectively, and roll in contact with the guide shaft 6 at an angle of 45 degrees. Further, two bearings 9 are provided on the left and right sides of the central portion, and are moved while contacting the lower surface of the fixed guide plate 10. The magnetic head 3 mounted on the mounting plate 7 is mounted on bearings 8 and 9 that roll while contacting the guide shaft 6 and the guide plate 10.
The positioning operation is performed by being guided in linear movement by.

As illustrated in FIG. 2, the bearing of the magnetic head positioning device of a magnetic disk device as described above includes an inner ring 12 fixed to a shaft 11, and a plurality of bearings held in a cage 15 coated with grease 17. The outer ring 13 has a plurality of balls 14 wound around it and holds shield plates 6a and 6b at both ends.

When such a bearing rotates, the grease sealed inside becomes oil mist and scatters to the outside of the bearing, causing D.
When floating in E, the oil mist adheres to the magnetic disk, and when the magnetic disk stops rotating in this state, the magnetic head comes into contact with the magnetic disk and comes to rest, so the next time the magnetic disk is rotated. If this occurs, the oil mist adhering to the magnetic disk and the magnetic head are attracted to each other, preventing the magnetic disk from starting its normal rotational operation, and sometimes causing a head crash.

[Problem to be solved by the invention]

The bearing of the conventional magnetic head positioning device mentioned above, the grease filled inside the bearing is normally filled from the - direction, the gap between the grease and the shield plate becomes small, and the grease may come into contact with the shield plate on the shaft. However, when such a bearing rotates, the grease becomes oil mist that scatters outside and floats inside the DE.

[Means to solve the problem]

The bearing of the magnetic head positioning device of the present invention includes an inner ring fixed to the shaft, a plurality of balls held in a cage coated with grease, and a shield plate wrapped around the plurality of balls at both ends. A bearing for a magnetic head positioning device having an outer ring has a structure in which a gap between the plurality of balls and shield plates provided at both ends of the outer ring is larger on the grease-filled side than on the opposite side.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a cross-sectional view showing one embodiment of the present invention.

In this embodiment, as shown in FIG. 1, a retainer 15 holding a plurality of balls 14 is positioned offset to one side from the center of the bearing inner ring 12 and outer ring 14.

The gaps between the plurality of balls 14 and the shield plates 16a and 16b provided at both ends of the outer ring 14 are larger than those between the balls 14 and the shield plates 16b, so that the grease flows from the shield plate 16b side. It is enclosed.

The bearing configured as described above maintains a sufficient clearance 18 between the sealed grease 17 and the shield plate 16b even when the magnetic head positioning device rotates as the magnetic head positioning device runs. This eliminates the possibility of oil mist occurring due to contact with the oil.

[Effect of idea]

As explained above, the bearing of the magnetic head positioning device of the present invention has the effect of eliminating oil mist generated due to contact between grease and the shield plate while the information positioning device is running. This has the effect of making the magnetic disk device highly reliable by preventing reading errors and head crashes caused by oil mist adhering to the magnetic disk surface.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a sectional view showing an example of a bearing of a conventional magnetic head positioning device,
FIG. 3 is a perspective view showing an example of a magnetic disk device included in the magnetic head positioning device. 11...shaft, 12...inner ring, 13...
... Outer ring, 14 ... Ball, 15 ...
Retainer, 16... Shield plate, 17...
・Grease, 18... Gap, 2...
Magnetic disk, 3...Magnetic head, 6...
...Guide shaft, 7...Mounting plate, 8,9...
・Bearing, 10... Information plate. Agent Patent Attorney Uchihara Oto No. 7 Condolence Diagram 2

Claims (1)

[Claims] A magnetic head positioning device having an inner ring fixed to a shaft, a plurality of balls held in a cage coated with grease, and an outer ring around which the plurality of balls are wound and having shield plates at both ends. 1. A bearing for a magnetic head positioning device, wherein a gap between the plurality of balls and shield plates provided at both ends of the outer ring is larger on the grease-filled side than on the opposite side.