JPH06197486A - Motor for driving magnetic disk - Google Patents

Abstract

PURPOSE:To obtain a magnetic disk driving motor wherein a member which does not generate a harmful gas or the like is used and a through hole in a shaft is sealed completely. CONSTITUTION:A magnetic disk driving motor is provided with a rotor magnet 2 which faces a stator core 1, with a hub 12 to which the rotor magnet 2 has been fixed and on which a magnetic disk has been mounted and with a shaft 5 which is turned integrally with the hub 12 and in which a through hole 12 passed through in the axial direction has been formed. The through hole 13 is closed with a slid member 9, and at leasy the circumference of the through hole 12 is covered with an adhesive 6.

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 motor, and more particularly to a sealing structure for a through hole formed in a shaft.

[0002]

2. Description of the Related Art For example, there is a motor shown in FIG. 3 as a motor for rotationally driving a magnetic disk or the like. In FIG. 3, the frame 30 has a dish-shaped portion and a cylindrical portion 30a integrally formed in the central portion thereof, and also has a mounting hole 31 in the outer edge portion. Outer rings of two upper and lower ball bearings 27, 27 are fitted and fixed on the inner peripheral side of the cylindrical portion 30a, and the inner ring of the ball bearings 27, 27 has a shaft 25 integrally formed at the center of the hub 29.
The outer peripheral portion of is fitted and fixed. As a result, the shaft 25 is rotatably supported. The shaft 25 formed integrally with the hub 29 has a tubular shape and has a through hole 3 in the axial direction at the center.
An elastic member 26 for preventing invasion of unclean gas or the like from the inside of the motor to the disk portion is attached in the through hole 32. Such a hub 29 is for holding a disc (not shown) integrally and rotationally driving it, is formed in a substantially cylindrical shape, and has a flange portion 23 for holding the disc on the outer peripheral portion. A cylindrical drive magnet 22 is fixed to the inner peripheral side of the hub 29.

The through hole 32 is necessary for screwing a clamp member for clamping the disk held by the hub 29. The reason for penetrating the through hole 32 instead of forming a dead end on the way is to prevent rust. This is because the surface treatment liquid reaches the details of the screw holes to form a uniform rust-preventive coating, and further, if the inside of the holes is penetrated, it can be completely cleaned. However, by providing the through hole 32, the internal space of the motor and the disk chamber communicate with each other through the through hole 32, the grease of the bearings 27, 27 is scattered, and the disk chamber is separated by the unclean air and gas inside the motor. To be polluted. Therefore, the through hole 3 is formed by the elastic member 26.
2 is blocked.

A stator core 21 is fitted and fixed to the outer peripheral side of the cylindrical portion 30a of the frame 30. The stator core 21 has a plurality of salient poles, each salient pole faces the inner peripheral surface of the drive magnet 22, and a coil is wound around each salient pole. The stator core 21 and the coils constitute a motor stator. Drive magnet 22
Constitutes the rotor of the motor.

As a kind of the magnetic disk driving motor as described above, there is one described in Japanese Patent Laid-Open No. 4-88857.

[0006]

As described above, in the conventional magnetic disk drive motor, the elastic member 26 is attached to the through hole 32 of the shaft 25 to seal the space, and the space from the inside of the motor to the disk chamber is reached. Was sealed. However, since the elastic member 26 is generally a rubber member, it easily generates gas, and this gas adversely affects the disk and the head. Further, since the elastic member 27 is easily removed and the sealing performance is not perfect, there is a problem such as air leak.

The present invention has been made to solve the above problems, and a magnetic disk drive capable of completely sealing a through hole of a shaft by using a member that does not generate harmful gas or the like. An object of the present invention is to provide a motor.

[0008]

In order to achieve the above object, the present invention provides a rotor magnet facing a stator core, a hub to which the rotor magnet is fixed and a magnetic disk is mounted, and the hub. A magnetic disk drive motor having a shaft integrally formed therewith and having a through hole formed therethrough in the axial direction, the through hole is closed with a solid member, and at least the periphery of the solid member is covered with an adhesive. It was

[0009]

The space from the space inside the motor to the disk chamber is sealed by closing the through hole of the shaft with a solid member and further covering at least the periphery of the solid member with an adhesive to seal the space.

[0010]

Embodiments of the magnetic disk drive motor according to the present invention will be described below with reference to the drawings. In FIG. 1, the frame 10 has a dish-shaped portion and a cylindrical portion 11 integrally formed at the center thereof. On the inner peripheral side of the cylindrical portion 11, two upper and lower ball bearings 7,
The outer ring 7 is fitted and fixed, and the outer circumference of the shaft 5 integrally formed in the center of the hub 12 is fitted and fixed to the inner rings of the ball bearings 7, 7. As a result, the hub 12 having the shaft 5 is rotatably supported. The shaft 5 formed integrally with the hub 12 is tubular and has a through hole 13 in the center, and a female screw is formed in the lower portion of the through hole 13. A solid member 9, which is a metal or plastic screw, is screwed into the female screw. The fitting portion between the through hole 13 and the solid member 9 is covered with the adhesive 6.

The hub 12 is for holding a disc (not shown) integrally and rotating it. The hub 12 is formed in a substantially cylindrical shape and has a flange portion 3 for holding the disc on the outer peripheral portion. . An appropriate number of disks are stacked on the flange 3 with a spacer interposed, and the clamper stacked thereon is screwed to the upper portion of the hub 12.
A cylindrical drive magnet 2 is fixed to the inner peripheral side of the hub 12.

A stator core 1 is fitted and fixed to the outer peripheral side of the cylindrical portion 11 of the frame 10. The stator core 1 has a plurality of salient poles, a coil is wound around each salient pole, and each protrusion is formed by the drive magnet 2 described above.
Facing the inner surface of the. The stator core 1 and the coil constitute a stator of the motor. The drive magnet 2 constitutes the rotor of the motor.

According to the magnetic disk drive motor as described above, the solid member 9 such as a screw is screwed into the through hole 13 at the center of the shaft 5, and the through hole 13 and the solid member 9 are fitted together. Since it is covered with the adhesive 6, no harmful gas is generated unlike the conventional one sealed with an elastic member, and since the fixing strength is large, the solid member 9 itself does not fall off. Further, since the inside of the motor and the portion where the disc is attached are completely cut off, it is possible to completely suppress the air leak.

As another embodiment, as shown in FIG.
In addition to fixing the solid member 9 with the adhesive 6 to block the space inside the motor from the disk mounting portion, the cover 14 is further mounted below it to secure the space where the ball bearing 7 is mounted. It may be closed. The cover 1
4 is formed in a dish shape, the outer edge portion of which is pressed against the lower surface of the outer ring of the lower ball bearing 7, and the outer edge portion of the cover 14 and the inner peripheral surface of the cylindrical portion 18 to which the ball bearing 7 is attached are glued. Cover with 15 and fix. With such a configuration, it is possible to prevent the impure gas containing oil mist generated from the ball bearing 7 from affecting the disc. Further, by forming the through hole, the inside of the hole can be completely cleaned, so that no dust is generated from inside the hole.

The solid member for closing the through hole of the shaft may be a screw having a head as in the illustrated embodiment, or may be a plug-like member without a screw thread, which means that the through hole is closed. Anything can be used. Further, the adhesive has only to cover at least the periphery of the solid member, and does not necessarily have to cover the entire solid member. It is not always necessary to form a screw in the through hole of the shaft.

[0016]

According to the present invention, since the through hole formed in the center of the shaft in the axial direction is closed with the solid member and the adhesive, harmful gas is generated or the solid member comes off. Without it, it is possible to completely block the space connecting the inside of the motor and the disk and completely prevent the entry and exit of unclean gas. Further, by forming the through hole, the inside of the hole can be completely cleaned, so that dust is not generated from the inside of the hole.

[Brief description of drawings]

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

FIG. 2 is a sectional view showing another embodiment of the magnetic disk drive motor according to the present invention.

FIG. 3 is a sectional view showing an example of a conventional magnetic disk drive motor.

[Explanation of symbols]

 1 Stator Core 2 Rotor Magnet 5 Shaft 6 Adhesive 9 Solid Member 12 Hub 13 Through Hole

Claims (1)

[Claims] 1. A rotor magnet that faces a stator core, a hub to which the rotor magnet is fixed and a magnetic disk is mounted, and a shaft that rotates integrally with the hub and has a through hole penetrating in the axial direction. A magnetic disk drive motor having: a magnetic disk drive motor, wherein the through hole is closed with a solid member, and at least the periphery of the solid member is covered with an adhesive.