JP2558186Y2 - Magnetic disk drive - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk drive in which a magnetic disk is mounted on a hub rotatably supported by bearings and driven to rotate.

[0002]

2. Description of the Related Art A magnetic disk drive having a structure as shown in FIG. 3 is generally known. In the figure, a core core 3 having a laminated structure is fitted and fixed to a large-diameter portion 2a on the lower side in the figure of a fixed shaft 2 which is integrally erected on a frame 1 and a coil is attached to the core core 3. 4 are wound. A pair of bearings 5 and 6 are fixed to the outer periphery of the illustrated upper-side small-diameter portion 2b of the fixed shaft 2 so as to be arranged in parallel in the axial direction.
The hub 7 is rotatably supported via the bearings 5 and 6. That is, the inner races 5a, 6a of the bearings 5, 6 are bonded and fixed to the outer peripheral surface of the fixed shaft 2, and the substantially hollow cylindrical hub 7 is fixed to the outer races 5b, 6b of the bearings 5, 6. ing. A magnetic disk (not shown) is mounted on the outer periphery of the hub 7.

At this time, on the inner peripheral surface of the hub 7, that is, on the bearing mounting surface 7 a, adhesive reservoir grooves 8, 9 are respectively annularly recessed at portions corresponding to the ball centers of the bearings 5, 6. . The bearings 5 and 6 are filled with the adhesive filled in the adhesive collecting grooves 8 and 9.
Has been fixed.

As shown in FIG. 4, a stepped portion 11 projecting annularly toward the shaft side is formed on a bearing mounting surface 7a of the hub 7 at a boundary portion between the bearings 5 and 6. It is projected. The outer races 5b and 6b of the bearings 5 and 6 are in contact with both end surfaces in the axial direction of the step portion 11, respectively.
Are supported and fixed at predetermined positions.

Further, a drive magnet 12 is provided on the inner peripheral wall of a skirt 7b provided on the lower side of the hub 7 in the figure.
Are fixed in an annular shape, and this drive magnet 12
The iron core 3 is arranged to face the outer peripheral surface. An electric wire (lead wire) 13 for applying a drive voltage to the coil 4 of the iron core 3 is drawn out of the motor through an insertion hole provided in the frame 1.

[0006]

However, in such a conventional device, as shown in FIG. 4, a relatively small curvature R1 is formed at the root of the step 11 provided on the bearing mounting surface 7a. It is necessary to provide the bearing flank 14, which is a problem in working and forming. In other words, in order to form a small curvature surface, the life of the cutting tool must be shortened, and it is necessary to frequently change the cutting tool, which causes a decrease in productivity.

Accordingly, an object of the present invention is to provide a magnetic disk drive capable of favorably forming the bearing mounting surface of the hub.

[0008]

In order to achieve the above object, the magnetic disk drive of the present invention mounts a magnetic disk on a hub rotatably supported by bearings and drives the hub to rotate. In the magnetic disk drive device, a step portion for supporting the bearing in the axial direction protrudes from a bearing mounting surface of the magnetic disk drive device, and an adhesive reservoir groove for fixing the bearing is recessed. Are formed so as to communicate with each other from the middle part in the axial direction of the outer race of the bearing to the root part of the step.

[0009]

According to the magnetic disk drive of the above means, since the curved surface portion of the adhesive reservoir functions as a bearing flank, the bearing flank having a relatively large curvature is provided at the root of the step. Is formed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 and 2 show a magnetic disk drive according to an embodiment of the present invention. The same components as those described in the related art are denoted by the same reference numerals, and the description thereof will be omitted. . The magnetic disk drive of the embodiment shown in FIGS. 1 and 2 is different from that of the prior art in that a stepped portion 1 provided on a bearing mounting surface 7a of a hub 7 is provided.
1 is that the adhesive reservoir grooves 21 and 22 are recessed at the root portion of 1. The adhesive reservoir grooves 21 and 22 are provided from the axially intermediate portions of the outer rings 5 b and 6 b of the bearings 5 and 6 to the step portion 11, and more specifically, correspond to the ball centers of the bearings 5 and 6. It is formed so as to communicate from the portion to the base of the step portion 11.
A curved surface having a radius of curvature R2 is formed in each of the adhesive reservoir grooves 21 and 22 at a portion corresponding to the root of the step portion 11.

According to this embodiment, the curved surface having a radius of curvature R2 provided in the adhesive reservoir grooves 21 and 22 functions as a bearing flank, and the radius of curvature R2 of the curved surface is equal to that of the conventional art. Can be set to be larger than the radius of curvature R1 of the bearing flank (R2> R1). That is, since a bearing flank having a relatively large curvature can be formed at the base of the step 11, the bearing flank can be formed by relatively easy processing.

Although the invention made by the present inventors has been specifically described based on the embodiment, the invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the invention. Needless to say. For example, the present invention can be similarly applied to a shaft rotation type device in which a shaft is supported so as to rotate.

[0013]

As described above, in the magnetic disk drive of the present invention, an adhesive reservoir groove is formed in the bearing mounting portion of the hub so as to communicate from the axial middle portion of the bearing to the bearing supporting step portion. Since the curved surface of the adhesive reservoir groove functions as a bearing flank, a bearing flank having a relatively large curvature can be formed at a root portion of the step by relatively easy processing. And the productivity of the magnetic disk drive can be improved.

[Brief description of the drawings]

FIG. 1 is a half cross-sectional view of a magnetic disk drive according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of a part of the magnetic disk drive shown in FIG.

FIG. 3 is a half transverse sectional view of a conventional magnetic disk drive.

FIG. 4 is an enlarged cross-sectional view of a part of the magnetic disk drive shown in FIG. 3;

[Explanation of symbols]

 2 Fixed shaft 5, 6 Bearing 5b, 6b Outer ring 7 Hub 11 Step

Claims (1)

(57) [Scope of request for utility model registration] A magnetic disk is mounted on a hub rotatably supported by a bearing and driven to rotate, and a step is provided on the bearing mounting surface of the hub to support a bearing in an axial direction. A magnetic disk drive device having a groove for fixing a bearing, the groove being in communication with the groove from the middle of the outer race of the bearing in the axial direction to the root of the step. A magnetic disk drive device characterized in that it is formed to perform