JP2002171711A - Spindle motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simply constituted spindle motor wherein the thickness thereof is reduced and the rotor thereof is resistant to its coming off. SOLUTION: The spindle motor 10 includes a fixedly installed bearing 12, a rotor 20 rotatably supported on a rotary shaft 24 fitted in the bearing, a stator 11 placed around the bearing, and a turntable 30 mounted on one end of the rotary shaft. The other end of the rotary shaft is abutted against a fixedly installed thrust board 18 and is thereby supported in the thrust direction, and the periphery of the rotor is provided with a flange portion 21a extending in the radial direction. By having the flange portion engaged with engaging portions 16a and 16b, formed on a base 16 supporting the bearing, on he side of the other end of the rotary shaft, the rotor is supported so that it is not moved in the thrust direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle motor for rotating a disk-shaped medium, for example.

[0002]

2. Description of the Related Art Conventionally, such a spindle motor has
For example, it is configured as shown in FIG. That is, in FIG. 4, the spindle motor 1 includes a stator 2 and a bearing 3.
And a turntable 5 attached to the upper end of the rotation shaft of the rotor 4.

[0003] The stator 2 includes a core 2 arranged in an annular shape.
a and a coil 2b wound around the core 2a.

[0004] The bearing 3 is a sintered bearing impregnated with lubricating oil. The bearing 3 is perpendicular to the stator 2 via a bearing housing 3 a at the center of the annular shape of the core 2 a of the stator 2. Fixed. The bearing housing 3a
Is mounted on an iron base 2c, and a stator substrate 2d is mounted on the iron base 2c.

[0005] On the other hand, the rotor 4 has a hollow cylindrical rotor yoke 4a having an open end, and a rotor yoke 4a.
Rotor magnet 4b mounted along the inner peripheral surface of
A bush 4c fixedly held at the center of the rotor yoke 4a, a rotating shaft 4d attached to the bush 4c,
It is composed of

The lower end of the rotating shaft 4d in FIG. 1 is attached to the thrust board 3b attached to the lower end of the bearing housing 3a so as not to move in the axial direction when mounted on the bearing 3. An annular resin stopper 6 attached to the bearing housing 3a is formed near the lower end of the bearing 3 so as to extend in the circumferential direction near the lower end of the rotating shaft 4d, while being in contact with the washer 3c. It is designed to engage within the annular groove 4e.

The turntable 5 has a known structure, and is configured to engage a center hole of, for example, a CD or a CD-ROM with a central turntable portion 5a to fix and hold the turntable.

[0008] The spindle motor 1 thus configured
According to this, when a current flows through the coil 2 b of the stator 2, the magnetic field generated in the coil 2 b interacts with the magnetic field of the rotor magnet 4 b via the rotor yoke 4 a of the rotor 4 to rotate the rotor 4. Will be done.

[0009]

However, in the spindle motor 1 having such a structure, in order to prevent the rotor from slipping off due to the external pressure, that is, to prevent the rotary shaft 4d from moving in the axial direction, a so-called slip-off preventing member is provided. The stopper 6 described above is used. The stopper 6 is formed separately from the bearing housing 3a of the bearing 3, and is attached to the bearing housing 3a by caulking or the like. For this reason, the number of parts increases and the number of assembling steps increases, so that the parts cost and the assembling cost increase, and there is a problem that the strength against the rotor detachment is relatively low. Further, there is a problem that the motor cannot be reduced in thickness by the stopper 6.

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a spindle motor which can be made thin with a simple structure and which has improved strength against rotor detachment.

[0011]

SUMMARY OF THE INVENTION According to the invention, it is an object of the invention to provide a fixedly arranged bearing (12) and a bearing (1).
2) A rotor (20) rotatably supported by a rotating shaft (24) mounted therein and having a disk-shaped medium mounted on its surface, and a stator (11) provided around a bearing (12). A spindle motor (10), comprising: a turntable (30) for holding a disk-shaped medium attached to one end of the rotating shaft (24).
, The other end of the rotary shaft (24) is supported in the thrust direction by abutting on a fixedly disposed thrust board (18), and the rotor (20)
Flange portion (21a) whose outer peripheral edge extends radially outward
The flange portion (21a) is provided with a bearing (1).
By engaging with the engaging portion (16a) provided on the base (16) supporting the 2) from the other end side of the rotating shaft (24), it is supported so as not to move in the thrust direction. A spindle motor (1
0) is achieved.

The spindle motor (10) according to the present invention,
(40) Preferably, the engaging portions (16a), (4)
1) is a hollow cylindrical burring that extends on the base (16) to one end of the rotating shaft (24), and the rotor (2)
After the mounting of (0) on the bearing (12), the peripheral edge on one end side is expanded outward.

The spindle motor (10) according to the present invention,
(40) Preferably, the engaging portions (16a), (4)
1) comprises a cylindrical pin mounted on a base (16) and having an enlarged portion (42) extending radially outward at an end edge on one end side of the rotating shaft (24).

A spindle motor (40) according to the present invention
Preferably, the cylindrical pin is a base (16)
Is fixedly held by caulking.

According to the above construction, the other end of the rotation shaft (24) of the rotor (20) is supported by the thrust board (18) in the thrust direction, and is radially outward from the outer peripheral edge of the rotor (20). Extending flange (21a)
Is engaged with the engaging portion (16a) provided on the base (16) from the other end side of the rotating shaft (24) so as not to move in the thrust direction,
Will be retained.

In this case, since the flange portion (21a) of the rotor (20) is formed integrally with the rotor (20), the number of parts is reduced, and the rotor (20) is connected to the rotating shaft (24). ), The flange portion (21a) is disposed at a predetermined position via the rotor (20), so that assembly can be easily performed, and component and assembly costs are reduced. Could be reduced. Further, the one end of the rotor (20) is pulled out by the flange portion (21) on the outer peripheral edge of the rotor (20).
a) and an engaging portion (16) provided on the base (16).
a), the strength of the rotor removal prevention is increased, the rotor removal can be reliably prevented, and the occupied space of the conventional resin stopper 6 is eliminated since the resin stopper 6 is unnecessary. It can be made thinner by the amount.

The engaging portion (16a) is provided on the base (16).
A hollow cylindrical burring extending to one end of the rotating shaft (24), the bearing (12) of the rotating shaft (24) of the rotor (20) being mounted on the bearing housing (15), and then being mounted on one end thereof. When the periphery of the is enlarged outward, the engaging portion (16a) is formed integrally with the base (16), and after the rotor (20) is mounted on the bearing housing (15), one end thereof is By enlarging the periphery, the assembly cost is reduced and the positional accuracy is improved.

The engaging portions (16a) and (41) have an enlarged portion (42) attached to the base (16) and extending radially outward at one end of the rotating shaft (24). In the case where the cylindrical pin is formed, the rotor (20) is mounted on the bearing housing (15), and then the cylindrical pin is mounted on the base (16), whereby the rotor (20) is easily assembled. At the same time, the position accuracy is improved.

When the cylindrical pin is fixedly held on the base (16) by caulking, the mounting strength of the cylindrical pin on the base (16) is improved, and the strength against the rotor coming off is improved. Will be enhanced.
The symbols in the parentheses are provided for easy understanding, are merely examples, and the present invention is not limited to these.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. FIG. 1 shows a configuration of a first embodiment of a spindle motor according to the present invention. In FIG. 1, a spindle motor 10 includes a rotor 11 rotatably supported by a stator 11 and a bearing 12.
0, and a turntable 30 attached to the upper end of the rotation shaft of the rotor 20.

The stator 11 includes a core 13 made of, for example, a silicon steel plate, and a coil 14 wound around the core 13.

The bearing 12 is, for example, a sintered bearing impregnated with lubricating oil. The bearing 12 is made of, for example, a brass bearing housing 1 at an annular center position of the core 13 of the stator 11.
5 and is fixed vertically to the stator 11. The bearing housing 15 is made of an iron base 16.
, And a stator substrate 17 is mounted on the iron base 16.

On the other hand, the rotor 20 includes a rotor yoke 21 made of, for example, an iron plate, a rotor magnet 22 attached along the inner peripheral surface of the rotor yoke 21, and a bush 23 integrally formed at the center of the rotor yoke 21.
And a rotating shaft 24 made of, for example, stainless steel attached to the bush 23.

The rotor yoke 21 is formed in a flat hollow cylindrical shape whose one end is open, and a rotor magnet 22 is fixed in a circumferential direction along an inner peripheral surface of the cylindrical shape by bonding or the like. The rotor magnet 22 is formed of a permanent magnet, or is appropriately magnetized in the circumferential direction.

The rotary shaft 24 is inserted into the bush 23 by press fitting or the like, and is fixed and held.

Further, the lower end of the rotating shaft 24 is attached to the lower end of the bearing housing 15 by caulking or the like so as not to move along the axial direction when the rotating shaft 24 is mounted on the bearing 12. , For example, through a nylon thrust washer 19.

The turntable 30 has a known structure, and is configured to hold a CD or a CD-ROM, for example, and is formed of a resin, for example.

The above configuration is substantially the same as the configuration of the conventional spindle motor 1 shown in FIG. 3, but the configuration of the spindle motor 10 according to the present invention is different in the following points. That is, the lower end of the outer peripheral edge of the rotor yoke 21 constituting the outer peripheral edge of the rotor 20 is provided with a flange portion 21a extending radially outward. On the other hand, on the base 16 on the side of the stator 11, a hollow cylindrical engaging portion 16a rising from the base 16 is provided at a position slightly outside the distance from the center of the rotary shaft 24 of the flange portion 21a. It is arranged.

The engaging portion 16a has an enlarged portion 16b whose upper end extends outward. The enlarged portion 16b has a tip on the rotating shaft 24 side slightly rotated from the track of the flange portion 21a of the rotor yoke 21. On the shaft 24 side, it is located above the flange portion 21a. The engaging portion 16a has a hollow cylindrical burring formed on the base 16 in advance, and the rotating shaft 24 to which the rotor 20 is attached is mounted in the bearing 12 in the bearing housing 15. Later, the upper edge of the engaging portion 16a is pressed from above with a punch to form an enlarged portion 16b that is enlarged in the radial direction.

The spindle motor 1 according to the embodiment of the present invention
0 is configured as described above and operates as follows. First, a disk-shaped medium is placed on the turntable 30. At that time, the center hole of the disk-shaped medium is engaged with the peripheral surface of the turntable 30, so that the disk-shaped medium can be positioned in a direction perpendicular to the rotation shaft 24. Thereafter, by passing a current through the coil 14 of the stator 11, the magnetic field generated in the coil 14 interacts with the magnetic field of the rotor magnet 22 via the rotor yoke 21 of the rotor 20, thereby rotating the rotor 20. Will be. Thereby, the disk-shaped medium is driven to rotate.

In this case, when the flange portion 21a formed at the lower end of the outer peripheral edge of the rotor yoke 21 rotates integrally with the rotor 20, the turntable 30, and the rotating shaft 24,
Enlarged portion 16b of engaging portion 16a provided on base 16
From below. As a result, the rotating shaft 24 is positioned in the thrust direction, so that the retaining strength of about 5 times is obtained as compared with the case where the conventional resin stopper is used. Could be prevented. Further, since the resin stopper 6 in the conventional spindle motor 1 shown in FIG. 4 is not required, the number of parts can be reduced, the parts cost and the assembly cost can be reduced, and the thickness is reduced by the occupied space. Can be done.

FIG. 2 shows a main part of a second embodiment of the spindle motor according to the present invention. 2, a spindle motor 40 has substantially the same configuration as the spindle motor 10 shown in FIG. 1, and instead of an engaging portion 16a formed integrally with the base 16, an engaging portion formed separately is provided. The configuration is different only in that 41 is provided. Therefore, the same components as those of the spindle motor 10 shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. FIG.
In (A), the engaging portion 41 is formed of, for example, a metal cylindrical pin, and has an enlarged portion 42 whose upper end extends radially outward and a boss extending downward from the center of the lower end. A portion 43 is provided. The engaging portion 41 is fixedly held to the base 16 by press-fitting the boss portion 43 into a mounting hole 16 c provided in the base 16.

According to the spindle motor 40 having such a configuration, the same operation as the spindle motor 10 shown in FIG. 1 is performed, and the flange portion 21a formed at the lower end of the outer peripheral edge of the rotor yoke 21 When rotating integrally with the table 30 and the rotating shaft 24, the base 1
6 is engaged from below with the enlarged portion 42 of the engaging portion 41 disposed on the upper surface. As a result, the rotating shaft 24 is positioned in the thrust direction, so that the retaining strength of about 5 times is obtained as compared with the case where the conventional resin stopper is used. Could be prevented.

After the boss 43 is inserted into the mounting hole 16c of the base 16, the engaging portion 41 may be crimped as shown by an arrow A in FIG. As a result, the mounting strength of the engaging portion 41 to the base 16 is increased, and the strength against the rotor coming off is also increased.

In the above embodiment, the bearing 12 is configured as an impregnated sintered bearing, but it is apparent that other types of bearings may be used. Further, in the above embodiment, the spindle motor 10 for rotating and driving a CD or CD-ROM has been described. However, the present invention is not limited to this, and the spindle motor 10 for rotating and driving another disk-shaped medium including a DVD or a DVD-ROM can be used. Obviously, the present invention can be applied to a spindle motor.

[0036]

As described above, according to the present invention, the other end of the rotating shaft of the rotor is supported by the thrust board in the thrust direction, and the flange portion extending radially outward from the outer peripheral edge of the rotor is provided. By engaging with the engaging portion provided on the base from the other end of the rotating shaft, the positioning is performed so as not to move in the thrust direction,
Will be retained.

In this case, since the rotor flange portion is formed integrally with the rotor, the number of components is reduced, and when the rotor is mounted on a rotating shaft, the flange portion is connected via the rotor. Since it is arranged at a predetermined position, assembly can be easily performed, and component costs and assembly costs can be reduced. Further, since the rotor is prevented from coming off to one end side by the engagement between the flange portion on the outer peripheral edge of the rotor and the engaging portion provided on the base, the strength of the rotor coming off prevention is increased, The dropout can be reliably prevented,
Since a conventional resin stopper is not required, it can be configured to be thinner by the thickness thereof.

Thus, according to the present invention, it is possible to provide an extremely excellent spindle motor which can be formed to be thin with a simple structure and which has improved strength against rotor detachment.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a configuration of a first embodiment of a spindle motor according to the present invention.

FIG. 2 is a partially enlarged sectional view showing a main part of a second embodiment of the spindle motor according to the present invention.

FIG. 3 is a partially enlarged sectional view showing a main part of a modification of the spindle motor of FIG. 2;

FIG. 4 is a schematic sectional view showing a configuration of an example of a conventional spindle motor.

[Explanation of symbols]

 10, 40 Spindle motor 11 Stator 12 Bearing 13 Core 14 Coil 15 Bearing housing 16 Base 16a, 41 Engagement part 16b, 42 Enlarged part 17 Stator board 18 Thrust board 19 Thrust washer 20 Rotor 21 Rotor yoke 21a Flange part 22 Rotor magnet 23 Bush 24 rotating shaft 30 turntable 43 boss

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3J011 BA08 BA09 KA02 KA03 LA01 SB19 5D109 BB01 BB12 BB17 BB21 BB22 5H605 AA20 BB05 BB14 BB19 CC02 CC03 DD05 EA01 EA16 EA19 EB03 EB06 GG04 GG20 5H621K19

Claims (4)

[Claims] 1. A fixedly arranged bearing, a rotor rotatably supported by a rotating shaft mounted in the bearing and having a disk-shaped medium mounted on its surface, and a stator provided around the bearing And a turntable attached to one end of the rotating shaft.In the spindle motor, the other end of the rotating shaft is supported in a thrust direction by contacting a fixedly arranged thrust board. And an outer peripheral edge of the rotor is provided with a flange portion extending outward in the radial direction. The flange portion is provided on the base supporting the bearing with an engaging portion provided from the other end of the rotating shaft. A spindle motor which is supported so as not to move in the thrust direction by being engaged. 2. The engaging portion is a hollow cylindrical burring that extends to one end of a rotating shaft on a base, and a peripheral edge of one end of the burring is enlarged outward after the rotor is mounted on a bearing. The spindle motor according to claim 1, wherein: 3. The method according to claim 1, wherein the engaging portion comprises a cylindrical pin mounted on a base and having an enlarged portion extending radially outward at one end of the rotating shaft. The spindle motor according to claim 1, wherein 4. The method according to claim 1, wherein the cylindrical pin is fixedly held on a base by caulking.
The spindle motor according to claim 3.