JPH0684554U - Magnetic disk drive - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a magnetic disk drive device capable of reducing the component cost and the assembly cost and reducing the product thickness without sacrificing the retaining effect of the rotary shaft. [Structure] A hub base 12 for mounting a magnetic disk is a rotating shaft 11.
Is mounted on the inner peripheral surface of a bottomed cylindrical rotor case 13 coupled to the hub base 12, and a stator core 14 wound with a coil 14a is opposed to the drive magnet 13a. Bearing 1
The rotating shaft 11 is held so as to be rotatable relative to each other via 8 and 19, and the bearing 19 is formed by magnetizing a sintered oil-impregnated bearing containing magnetic powder.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a hub base for mounting a magnetic disk fixed to a rotating shaft, a drive magnet provided on the inner peripheral surface of a bottomed cylindrical rotor case connected to the hub base, and the drive magnet. The present invention relates to a magnetic disk drive device including a stator core around which a coil facing each other is wound, and a bearing holder that holds the rotary shaft so as to be relatively rotatable via at least one bearing.

[0002]

[Prior art]

 Conventionally, as shown in FIG. 3, a hub base 2 fixed to a rotary shaft 1 and on which a magnetic disk (not shown) is mounted, and a bottomed cylindrical rotor case 3 coupled to the hub base 2 are provided. A drive magnet 3a provided on the inner peripheral surface and a stator core 4 wound with a coil 4a facing the drive magnet 3a are provided, and the rotor case 3 causes the hub case 2 to move the rotor case 3 by the current flowing through the coil 4a and the magnetic field of the drive magnet 3a. There is a magnetic disk drive device D configured to rotate integrally with the magnetic disk drive device D.

The stator core 4 is fixed to the substrate 5 via screws 6, and the flange portion 7 a of the bearing holder 7 is sandwiched between the substrate 5 and the stator core 4. The rotating shaft 1 is held by the cylindrical portion 7b of the bearing holder 7 via bearings 8a and 8b so as to be relatively rotatable on the inner peripheral surface thereof, and a retaining ring 9 fitted near the end portion of the rotating shaft 1 serves as an arrow mark. It is locked in the direction.

[0004]

[Problems to be solved by the device]

 By the way, in the magnetic disk drive device D configured as described above, the retaining ring 9 fitted to the rotating shaft 1 prevents the rotating shaft 1 in the direction of arrow A from coming off. There has been a problem that the cost increases because machining of the shaft 1 and work of fitting the retaining ring 9 are required.

Moreover, since it is necessary to secure a height for fitting the retaining ring 9 to the rotating shaft 1, not only the thinning of the entire apparatus must be sacrificed, but also the assembling in the opposite direction. Therefore, there is a problem that it is not suitable for a type in which the apparatus main body is stacked and used.

In view of the above situation, the present invention provides a magnetic disk drive device capable of reducing the component cost and the assembly cost and reducing the product thickness without sacrificing the retaining effect of the rotary shaft. The purpose is to do.

[0007]

[Means for Solving the Problems]

 In order to achieve the object, the present invention is provided on the inner peripheral surface of a hub base for mounting a magnetic disk fixed to a rotary shaft and a bottomed cylindrical rotor case connected to the hub base. A magnetic disk drive device comprising: a drive magnet; a stator core around which a coil facing the drive magnet is wound; and a bearing holder that holds the rotary shaft rotatably through at least one bearing. At least one of the bearings is a sintered oil-impregnated bearing containing magnetic powder, and the gist is that the sintered oil-impregnated bearing is magnetized.

[0008]

[Action]

 In such a configuration, the hub base for mounting the magnetic disk is fixed to the rotating shaft, and the drive magnet is provided on the inner peripheral surface of the bottomed cylindrical rotor case coupled to the hub base to wind the coil. The stator core is opposed to the drive magnet, and the rotating shaft is held in the bearing holder so as to be relatively rotatable through at least one bearing. Used products are used.

[0009]

【Example】

 Next, an embodiment of the magnetic disk drive device of the present invention will be described with reference to the drawings.

In FIG. 1A, a magnetic disk drive device 10 includes a hub base 12 for mounting a magnetic disk fixed to a rotating shaft 11 and a drive magnet connected to the hub base 12 and having an inner peripheral surface. A rotor case 13 having a bottomed cylindrical shape provided with 13a and a stator core 14 around which a coil 14a facing the drive magnet 13a is wound, and the hub base 12 is formed by the current flowing through the coil 14a and the magnetic field of the drive magnet 13a. The rotor case 13 is configured to rotate as a whole.

The stator core 14 is fixed to the substrate 15 via screws 16, and the flange portion 17 a of the bearing holder 17 is sandwiched between the substrate 15 and the stator core 14.

The rotating shaft 11 is held by the cylindrical portion 17 b of the bearing holder 17 via bearings 18 and 19 so as to be relatively rotatable on its inner peripheral surface. Therefore, the bearing holder 17 is positioned on the substrate 15 by engaging the end of the cylindrical portion 17b with the opening of the substrate 15 and holds the rotating shaft 11 coaxially.

At least one of the bearings 18 and 19 (for example, the bearing 19) is made of a sintered oil-impregnated bearing containing magnetic powder, and the sintered oil-impregnated bearing 19 is magnetized. . The magnetized teeth are set so that the magnetic poles are alternately superposed in a direction intersecting the axis of the rotating shaft 11, as shown in FIG. 1 (B).

In order to assemble the magnetic disk drive 10 having the above-described structure, first, the rotor case 13 having the drive magnet 13a on the inner peripheral surface thereof is connected to the rotary shaft 11 via the hub base 12 to form a unit. The bearing holder 17 is mounted on the inner peripheral surface of the cylindrical portion 17b through the bearings 18 and 19.

Next, the flange portion 17 a of the bearing holder 17 is positioned so as to be sandwiched between the substrate 15 and the stator core 14, and then the stator core 14 is fixed to the substrate 15 with the screw 16.

When the rotor case 13 is rotated integrally with the hub base 12 by the current flowing through the coil 14a and the magnetic field of the drive magnet 13a, even if the rotating shaft 11 tries to come out from the cylindrical portion 17b in the arrow B direction. The magnetic force of the bearing 19 prevents this coming off.

By the way, in the above embodiment, one of the two bearings 18 and 19 is magnetized, but both bearings may be magnetized. Further, as shown in FIG. 2, the present invention can be applied to the magnetic disk drive device 20 in which the rotating shaft 11 is held by one bearing 29. In FIG. 2, components having the same operations as those of the above-described embodiment are designated by the same reference numerals and the description thereof will be omitted.

[0018]

[Effect of device]

 As described above, in the magnetic disk drive device of the present invention, at least one of the bearings is a sintered oil-impregnated bearing containing magnetic powder, and the sintered oil-impregnated bearing is magnetized. As a result, it is possible to reduce the component cost, the assembly cost and the product thickness without sacrificing the retaining effect of the rotary shaft.

[Brief description of drawings]

FIG. 1 shows a magnetic disk drive device of the present invention, (A)
Is a vertical cross-sectional view of a main part, and (B) is an explanatory view of a bearing.

FIG. 2 is a vertical cross-sectional view of a main part showing a second embodiment of the magnetic disk drive device of the present invention.

FIG. 3 is a vertical cross-sectional view of a main part of a conventional magnetic disk drive device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Magnetic disk drive device 11 ... Rotating shaft 12 ... Hub stand 13 ... Rotor case 13a ... Drive magnet 14 ... Stator core 14a ... Coil 17 ... Bearing holder 19 ... Bearing

Claims (1)

[Scope of utility model registration request] 1. A hub base for mounting a magnetic disk fixed to a rotating shaft, a drive magnet provided on an inner peripheral surface of a bottomed cylindrical rotor case connected to the hub base, and the drive magnet. In a magnetic disk drive comprising a stator core wound with a coil facing each other, and a bearing holder that holds the rotating shaft relatively rotatably via at least one bearing, at least one of the bearings is made of magnetic powder. A magnetic disk drive device comprising a sintered oil-impregnated bearing contained therein, wherein the sintered oil-impregnated bearing is magnetized.