JPH0928070A - Brushless motor - Google Patents

Abstract

(57) [Abstract] [Purpose] In a brushless motor used in a magnetic disk drive, it was resolved that the rotating body supported by a fluid bearing would fall out of the bearing due to external force such as vibration or shock. Another object of the present invention is to provide a brushless motor that does not hinder the magnetic disk drive device. [Structure] In order to prevent the rotating shaft 2 from coming off the sleeve 3, the sleeve 3 and the retaining member 9a are screw-fastened and installed to prevent the rotating body from coming off due to external force such as vibration and impact. The motor can rotate stably. Furthermore, since the retaining member 9a is installed by the screw mechanism, it is possible to finely adjust the position of the retaining member 9a, and it is possible to prevent contact between the rotating body and the retaining member 9a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brushless motor (hereinafter abbreviated as a motor) used mainly in a magnetic disk drive.

[0002]

2. Description of the Related Art In recent years, HDD devices in the field of office automation have become higher in density and higher in speed, and motors for driving disks are required to have stable accuracy, while miniaturization and thinning are strongly demanded. Has been done.

The structure of a conventional motor will be described below with reference to FIG. As shown in FIG. 5, the hub 1 a is supported by the rotating shaft 2. The rotary shaft 2 is inserted into the bearing hole of the sleeve 3, and the thrust plate 4 is installed so as to face the end surface of the rotary shaft 2. The sleeve 3 is supported by the bracket 5a, and the core 6 is supported by the bracket 5a. The rotor frame 7 is supported by the hub 1 a, and the magnet 8 is installed inside the rotor frame 7 so as to face the core 6.

[0004]

However, in the conventional motor, since the rotary shaft 2 is inserted into the bearing hole of the sleeve 3, the rotary shaft 2 is not affected by an external force such as vibration or shock.
Could fall out of the bearing hole.

Further, when the thrust plate 4 is caulked and attached to the sleeve 3, the outer diameter of the caulked portion 3a of the sleeve 3 is deformed, so that the dimension L of the sleeve 3 protruding from the bracket 5a cannot be eliminated. .

Further, as a method of installing the core 6 on the bracket 5a, it has been fixed by using an adhesive. However, in this method, it is necessary to wait until the adhesive is completely cured, and the working process is stopped during that time, and the working efficiency is reduced. Moreover, if the curing of the adhesive is incomplete, the uncured portion of the adhesive may directly enter the hydrodynamic bearing and that the uncured portion of the adhesive does not dissolve in the cleaning liquid during the cleaning process that is essential for the magnetic disk drive motor. There is a possibility that the cured adhesive may indirectly enter the fluid bearing through the adhesive.
Further, the adhesive may generate gas, which may adversely affect the magnetic disk.

The present invention solves the above problems and provides a thin motor in which the rotating body does not fall out, and further improves the work efficiency of the motor assembly process and the influence of the uncured adhesive on the fluid bearing. The purpose is to eliminate.

[0008]

In order to achieve the above object, the present invention provides a threaded portion on a sleeve of a motor so that a retaining member can be installed on the threaded portion, and a mechanism of the threaded portion is provided. A motor capable of finely adjusting the position of the retaining member was used.

A counterbore is provided at the joint between the bracket and the sleeve. Further, the bracket and the core were fastened and fixed by caulking.

[0010]

With the above structure, the retaining member can be installed by providing the threaded portion on the sleeve. As a result,
The rotating shaft inserted in the bearing hole of the sleeve does not fall out of the bearing hole, and the motor can rotate stably.

Further, by providing the counterbore portion at the joint portion between the bracket and the sleeve, the caulked portion of the sleeve deformed by crimping the thrust plate can be released to the counterbore portion, and as a result, the sleeve is removed from the bracket. Since the protruding size can be eliminated, the motor can be made thinner.

By crimping the bracket and the core, the motor assembly process can proceed to the next step immediately after the crimping. Moreover, since no adhesive is used, there is no effect of the adhesive on the hydrodynamic bearing. As a result, the work efficiency of the motor assembly process can be improved and the rationalization of the motor assembly process can be realized.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1, 2, 3 and 4.

As shown in FIG. 1, a hub 1a forming a rotor is supported by a rotary shaft 2. The hub 1a is provided with a through hole 1b. The sleeve 3 is provided with a screw portion 3b, the rotary shaft 2 is inserted into a bearing hole of the sleeve 3, and the thrust plate 4 is installed so as to face the end surface of the rotary shaft 2. The sleeve 3 is supported by the bracket 5a,
The core 6 is supported by being crimped to the bracket 5a. The rotor frame 7 is supported by the hub 1 a, and the magnet 8 is installed inside the rotor frame 7 so as to face the core 6. The threaded portion 3b of the sleeve 3 is provided with a retaining member 9a shown in FIG. 2, and the retaining member 9a is provided with a convex portion 9b and a cutout portion 9c. A counterbore portion 10 is provided on the bracket 5a.

The operation of the above structure will be described below. In order to prevent the rotating shaft 2 from coming off from the sleeve 3, a retaining member 9a is installed on the threaded portion 3b of the sleeve 3 so that the rotating body does not come off due to an external force such as vibration or impact, and the motor becomes stable. It becomes possible to rotate. Further, since the retaining member 9a is installed on the screw portion 3b, the retaining member 9a
It is possible to finely adjust the position, and it is possible to prevent contact between the rotating body and the retaining member 9a. Here, a method of incorporating the retaining member 9a shown in FIG. 2 will be described with reference to FIG. As shown in FIG. 3 (a), the retaining member 9 a is slanted and is passed through the rotary shaft 2, and the convex portion 9 b of the retaining member 9 a is inserted into the inner diameter concave portion of the hub 1 a. At this time, the retaining member 9a is shown in FIG.
become that way. Next, the rotary shaft 2 is inserted into the sleeve 3 so that the center of the retaining member 9a and the center of the rotary shaft 2 are aligned with each other. The sleeve 3 has a screw portion 3b for installing the retaining member 9a.
The retaining member 9a is attached to b. The attachment method is to insert the rod into the through hole 1b of the hub 1a, hook the end of the rod into the notch 9c of the retaining member 9a, and then rotate the rotating body and the retaining member 9a together to attach the sleeve 3 to the sleeve 3. Tighten the screws against. As a result, the retaining member 9a is installed on the threaded portion 3b of the sleeve 3.

Next, by providing the counterbore 10 at the joint between the bracket 5a and the sleeve 3, the caulking 3a of the sleeve 3 deformed by crimping the thrust plate 4 can be released to the counterbore 10. A thinner motor can be realized.

Further, as shown in FIG. 4, the bracket 5a and the core 6 are fastened and fixed by the caulking portion 5b on the bracket 5a.
It is crimped by providing. In the conventional fastening and fixing method using adhesive, it was necessary to wait until the adhesive was completely cured, but the motor assembly process was stopped for the complete curing time.
By caulking the fastening and fixing, it is possible to proceed to the next process immediately after caulking, which can improve the work efficiency of the motor assembling process and realize the rationalization of the motor assembling process.

[0018]

As described above, according to the present invention, by providing a threaded portion on a sleeve and installing a retaining member on the threaded portion, it is possible to realize a motor in which a rotating body does not come off due to an external force such as vibration or impact. Is.

Further, by providing the counterbore part on the bracket, the caulking part of the sleeve deformed by the caulking of the thrust plate can be released to the counterbore part, and a thin motor can be realized.

Further, by caulking the bracket and the core for fastening and fixing, it becomes possible to proceed to the next step immediately after caulking in the motor assembling process, improving the work efficiency of the motor assembling process and rationalizing the motor assembling process. Can be realized.

[Brief description of drawings]

FIG. 1 is a sectional view of a motor according to an embodiment of the present invention.

FIG. 2 is a perspective view of a retaining member that constitutes a motor according to an embodiment of the present invention.

FIG. 3 is a diagram showing a method for attaching the retaining member of the present invention.

FIG. 4 is a diagram showing a crimping process of a bracket and a core according to an embodiment of the present invention.

FIG. 5 is a sectional view of a conventional motor

[Explanation of symbols]

 1a hub 1b through hole 2 rotary shaft 3 sleeve 3a caulking part 3b screw part 4 thrust plate 5a bracket 5b caulking part 6 core 7 rotor frame 8 magnet 9a retaining member 9b convex part 9c notch part 9d screw part 10 counterbore part

Claims (4)

[Claims] 1. A bracket main body, a hub that rotates relative to the bracket main body, a rotary shaft that supports the hub, and an open end side of the rotary shaft that supports the rotary body. A sleeve supported by the bracket, a thrust plate installed on the sleeve so as to face the open end surface of the rotary shaft, and a fluid bearing formed by the rotary shaft, the sleeve, and the thrust plate. When a retaining member for preventing the rotation shaft from coming off and a sleeve are provided with a threaded portion, and the retaining member is installed on the threaded portion of the sleeve by tightening a screw, and when an external force is applied to the motor body. A brushless motor, characterized in that the retaining member is prevented from coming off from a bearing by contacting a portion of the rotating body. 2. A sleeve is provided with a threaded portion, and a retaining member provided with the threaded portion is installed by screwing and fastening to the threaded portion of the sleeve, and the retaining member is secured by the screwing and fastening. 2. The brushless motor according to claim 1, wherein the position of the retaining member can be finely adjusted by a screw mechanism because the brushless motor is installed. 3. A bracket main body, a hub that rotates relative to the bracket main body, a rotating shaft that supports the hub, and a rotating body that is supported on the open end side of the rotating shaft. In a supported sleeve having a thrust plate installed on the sleeve so as to face the end surface of the rotating shaft, a counterbore portion is provided in the axial direction around the joint end portion of the sleeve and the bracket, and the counterbore is provided. A brushless motor, characterized in that a portion of the sleeve where the thrust plate is installed protrudes. 4. A rotating hub, a rotating shaft supporting the hub, a sleeve supporting the rotating shaft, a thrust plate installed to face the end face of the rotating shaft, and a rotating body. A bracket, a core installed on the bracket, the rotary shaft, the sleeve, and the thrust plate constitute a fluid bearing, and the bracket and the core are fastened and fixed by caulking. And brushless motor.