JPH0518271U - Magnetic disk drive motor - Google Patents

Abstract

(57) [Abstract] [Purpose] The shaft 13 and the hub 1 are constructed with a simple structure.
It is possible to improve the joint strength and joint rigidity with the hub 5, and to improve the rotation accuracy of the hub 15. When connecting the shaft 13 and the hub 15, at least the outer peripheral surface of the collar-shaped fixed body 14 of the shaft 13 is brought into contact with the inner peripheral wall of a mounting hole 16 provided on the hub 15 side, and the shaft 13 and the hub 15 are connected. It is designed to expand the contact area at the joint with 15.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a magnetic disk drive motor for rotating a magnetic disk.

[0002]

[Prior Art]

 A disk drive motor of a commonly used disk drive device has a structure as shown in FIG. 5, for example.

In FIG. 5, a hollow cylindrical bearing holder 2 is integrally erected at a substantially central portion of the frame 1, and a pair of ball bearings 3 are provided in the hollow inside of the bearing holder 2. The shaft 4 is rotatably supported. A disc-shaped rotor hub 5 is crimped and fixed to one end (upper end in the drawing) of the shaft 4. An annular drive magnet 6 is installed on the inner peripheral wall surface of the outer peripheral flange portion 5a of the rotor hub 5. On the other hand, a stator core 7 is fixed to the outer peripheral portion of the bearing holder 2 on the frame 1 side, and the outer peripheral surface of the stator core 7 faces the inner peripheral side of the drive magnet 6. A core winding 8 is loaded on the stator core 7.

A mounting hole 5b is formed in the center of the hub 5 described above, and a fixing screw 9 fitted in the mounting hole 5b is screwed to the upper end of the shaft 4 in the figure. The hub 5 is joined and fixed by this.

[0005]

[Problems to be solved by the device]

 However, in such a conventional hub mounting structure, since the contact / contact area of the portion where the mounting hole 5b of the hub 5 and the shaft 4 are coupled is set small, the coupling strength and coupling rigidity are insufficient. There are cases. In particular, when mounting a magnetic disk on the hub, high rotational accuracy is required, so it is necessary to increase the coupling strength and coupling rigidity between the hub and the shaft.

It is an object of the present invention to provide a magnetic disk drive motor capable of fixing a hub and a shaft with high strength and high rigidity by a simple structure.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a magnetic disk drive motor in which a mounting hole provided in a hub for mounting a magnetic disk is fixed to one end of the shaft. Is provided with a collar-shaped fixing body, and the hub mounting hole is fitted to the shaft side so as to abut at least the outer peripheral surface of the collar-shaped fixing body. is doing.

Further, the invention described in claim 2 has a structure in which a hub mounting hole is abutted on the outer peripheral surface and the axial end surface of the collar-shaped fixed body provided on the shaft.

[0009]

[Action]

 In the means having such a structure, at the time of connecting the shaft and the hub, at least the outer peripheral surface of the collar-shaped fixed body of the shaft is brought into contact with the mounting hole of the hub. A large contact area is secured at the joint part of the, and the joint strength and joint rigidity of both are increased.

According to the second aspect of the present invention, since the connecting portion between the shaft and the hub has an abutting structure, more stable connection and fixing can be achieved.

[0011]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, as shown in FIG. 2, a pair of bearing ball bearings 12, 12 are arranged side by side in the axial direction inside the hollow cylindrical bearing holder 11 provided on the frame side. The shaft 13 is press-fitted and rotatably supported by the pair of ball bearings 12, 12.

Further, as shown in FIG. 1, at one end portion (upper end portion in the drawing) of the shaft 13, a collar-shaped fixed body 14 formed in a large-diameter disc shape is integrally provided. At the same time, a mounting hole 16 penetratingly formed in the center of the hub 15 is fitted into the collar-shaped fixed body 14. The entire hub 15 is formed into a substantially hollow cylindrical shape, and a magnetic disk (not shown) is mounted on the outer peripheral surface thereof. A step portion is formed in the inner peripheral wall of the mounting hole 16 of the hub 15 in the axial direction, and the collar-shaped fixing body 14 of the shaft 13 is abutted against the step portion of the mounting hole 16. It is fixed.

That is, the stepped portion of the mounting hole 16 has a large-diameter portion 16a provided on the lower side in the figure, a small-diameter portion 16b provided on the upper side in the figure, and a radius connecting these two portions 16a, 16b. The direction extending portion 16c is provided. The collar-shaped fixing body 14 provided on the shaft 13 is such that the outer peripheral surface of the collar-shaped fixing body 14 is in contact with the large-diameter portion 16 a of the mounting hole 16 and the collar-shaped fixing body of the shaft 13 is fixed. The outer peripheral portion of the upper end surface in the figure of the body 14 is in contact with the radially extending portion 16 c of the mounting hole 16.

A skirt-shaped enlarged flange portion 17 is provided on the lower portion of the hub 15 in the drawing, and an annular drive magnet 18 is installed on the inner peripheral wall surface of the flange portion 17. Has been done. On the other hand, a stator core 19 is fixed to the outer peripheral portion of the bearing holder 11, and the outer peripheral surface of the stator core 19 faces the inner peripheral side of the drive magnet 18. A core winding 21 is loaded on the stator core 19.

Further, a magnetic fluid seal 22 is attached to the lower end of the shaft 13 in the figure.

In such an embodiment, when connecting the shaft 13 and the hub 15, at least the outer peripheral surface of the collar-shaped fixing body 14 of the shaft 13 is provided in the mounting hole 16 of the hub 15. The inner peripheral wall surface of the diameter portion 16a is abutted. For this reason, a large contact / contact area is secured at the connecting portion between the shaft 13 and the hub 15, and the connecting strength and connecting rigidity between the shaft 13 and the hub 15 are enhanced.

In addition, in this embodiment, since the collar-shaped fixing body 14 on the shaft 13 side is abutted against the radially extending portion 16c provided in the mounting hole 16 of the hub 15, a more stable coupling is achieved. The fixing is performed, and the runout accuracy of the outer peripheral mounting surface of the hub 15 on which the magnetic disk is mounted can be suppressed to be small. In addition, vibration resistance and shock resistance can be improved.

Next, in the second embodiment in which the same components as those of the first embodiment are represented by the same reference numerals in FIG. 3, the collar-shaped fixing body 24 provided on the shaft 13 is formed to have a slightly smaller diameter. The collar-shaped fixing body 24 is inserted into the mounting hole 26 formed on the hub 15 side from the upper side in the drawing, and is fitted while being abutted. According to such a second embodiment as well, it is possible to obtain substantially the same actions and effects as those of the first embodiment.

Further, in the third embodiment in which the same components as those in the first embodiment are represented by the same reference numerals in FIG. 4, a step portion for abutment is provided in the mounting hole 36 on the hub 15 side. First, the mounting holes 36 are formed so as to have a straight shape with the same diameter. Therefore, when connecting the shaft 13 and the hub 15, only the outer peripheral surface of the collar-shaped fixing body 34 of the shaft 13 is brought into contact with the mounting hole 36 of the hub 15. Also according to the third embodiment as described above, it is possible to obtain substantially the same actions and effects as those of the respective embodiments.

[0020]

[Effect of the device]

 As described above, according to the present invention, when connecting the shaft and the hub, at least the outer peripheral surface of the collar-shaped fixed body provided on the shaft is brought into contact with the inner wall of the mounting hole on the hub side to connect the shaft and the hub. Since the contact area in the portion is enlarged, the coupling strength and coupling rigidity between the shaft and the hub can be improved with a simple structure, and the rotation accuracy of the hub can be enhanced.

[Brief description of drawings]

FIG. 1 is a partial vertical cross-sectional view showing a fitted state of a shaft and a hub of a magnetic disk drive motor according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional explanatory view showing the overall structure of a magnetic disk drive motor to which the present invention is applied.

FIG. 3 is a partial vertical sectional view corresponding to FIG. 1, showing another embodiment of the present invention.

FIG. 4 is a partial longitudinal sectional view corresponding to FIG. 1 showing still another embodiment of the present invention.

FIG. 5 is an explanatory longitudinal sectional view showing an example of a conventional magnetic disk drive motor.

[Explanation of symbols]

 11 Bearing holder 13 Shaft 14, 24, 34 Collar-shaped fixed body 15 Hub 16, 26, 36 Mounting hole

Claims (2)

[Scope of utility model registration request] 1. A magnetic disk drive motor in which a mounting hole provided in a hub for mounting a magnetic disk is fixed to one end portion of a shaft, and a flange-shaped fixing member is provided at one end portion of the shaft. A motor for driving a magnetic disk, wherein a body is provided, and a mounting hole of the hub is fitted to a shaft side so as to abut at least an outer peripheral surface of the collar-shaped fixed body. 2. The magnetic disk drive motor according to claim 1, wherein the outer peripheral surface and the axial end surface of the collar-shaped fixed body provided on the shaft are abutted against the wall surface formed in the mounting hole of the hub. A magnetic disk drive motor characterized in that