JPH09219953A - Spindle motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a motor requiring no caulking work by forming a bearing holding portion at a lower thrust washer and clamping a radial bearing with the washer and a substrate. SOLUTION: A flange portion 5a linking with a transparent hole 10 of a substrate 21 is provided on the outer periphery in a lower portion of a radial bearing 5, and the substrate 21 is inserted. On the other hand, the lower surface of a plane portion 24a of a lower thrust washer is contacted to the substrate 21, the tip of a standing portion 24b (cylindrical portion) rising vertically from a plane portion 24a forms a collar portion 24c, and the radial bearing 5 is clamped with the substrate 21 and a bearing holding portion consisting of the standing portion 24b and the collar portion 24c. This clamping force is realized by an attracting force between a drive magnet 19 and the substrate so that no caulking work is required. Thus, there is no possiblity of applying an excessive force to part of a radial bearing 5 and damaging the radial bearing or of worsening the flatness of a frame by strain due to the excessive force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a spindle motor, and more particularly to improvement of quality maintenance and repair of the spindle motor.

[0002]

2. Description of the Related Art FIG. 4 is a sectional view of a conventional example showing one aspect of a spindle motor, which is shown in Japanese Patent Laid-Open No. 4-95609.

In the figure, a face-to-face type spindle motor 1 is shown.
Is mounted on the frame 6 at the outer peripheral portion of the radial bearing 5 by supporting the lower portion of the rotary shaft 4 in the radial direction by a radial bearing 5 which is firmly fixed to the through hole 10 opened in the frame 6 by caulking or the like. The thrust ball bearing 3 formed of the balls 14 arranged on the retainer 11 arranged on the washer 12 formed of a ring-shaped flat plate causes the collar-shaped portion of the rotating shaft 4 toward the outer peripheral surface from the rotating shaft toward the center of the drawing. A table 7 forming 13 and a hub base 8 provided on the table are supported in the thrust direction. Further, a drive magnet 9 in which S poles and N poles are alternately arranged is provided inside the outer peripheral portion of the table 7 in a ring shape, and these constitute a rotor. On the other hand, the coil 2 is attached to the frame 6 at a position opposite to the drive magnet 9 so as to face each other at a constant interval to form a stator. With this configuration,
By applying a drive current to the coil 2, a magnetic interaction occurs between the coil 2 and the magnet 9 to rotate the motor.

As described above, the radial bearing 5 and the frame 6
Is firmly fixed to the through hole 10 opened in the frame 6 by caulking or the like. If this caulking process is not performed with a uniform and predetermined force, an excessive force is applied to a part of the radial bearing 5 to damage the radial bearing 5, or the distortion deteriorates the flatness of the frame 6 and causes the rotation of the motor. The harmful effect of generating wah occurs. Further, once caulking or the like is performed as described above, it is difficult to disassemble the radial bearing 5 and the frame 6, and the motor cannot be partially repaired. For this reason, the entire motor must be replaced, which is economically disadvantageous.

[0005]

Therefore, according to the present invention, the inner peripheral edge of the lower thrust washer of the thrust ball bearing is raised to form an upright portion and a collar-shaped portion, and the upright portion (cylindrical portion) and the raised upright portion. By holding the metal bearing between the lower thrust washer and the substrate with the bearing holding portion formed of a grooved portion, it is possible to provide a spindle motor that does not need to fix the metal bearing to the through hole opened in the frame by caulking or the like. It is also. With this spindle motor, there is no fear that excessive force will be applied to part of the radial bearing due to caulking etc. to damage the metal bearing, or distortion due to excessive force will not deteriorate the flatness of the frame, and the quality will be improved. Since the motor can be partially repaired, it is highly economical.

[0006]

SUMMARY OF THE INVENTION Therefore, claim 1 of the present invention is provided.
Relates to a rotor having a rotary shaft and a drive magnet, a radial bearing for supporting the rotor in the radial direction, a thrust ball bearing for supporting the rotor in the thrust direction, and having a ball and a thrust washer. And a substrate on which the radial bearing is mounted, the thrust washer of the thrust ball bearing provided on the substrate side has a bearing holding portion that is bent toward the radial bearing side. A bearing holding portion holds the radial bearing together with the substrate.

In a spindle motor according to a second aspect of the present invention, the thrust ball bearing has a retainer for holding a ball, the bearing holding portion has an annular cylindrical portion, and the cylindrical portion has the retainer. It is characterized in that it faces the inner peripheral surface.

In the spindle motor according to claim 3 of the present invention, the substrate is made of a magnetic material, and the drive magnet is magnetically attracted to the substrate side.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment in which the present invention is applied to a spindle motor for driving a media disk or the like, and is contrasted with the spindle motor shown in FIG. Members having the same functions as those in FIG. 4 will be described with the same reference numerals.

In FIG. 1, reference numeral 20 is a circumferentially opposed spindle motor for driving a floppy disk. Sign 2
Reference numeral 2 denotes a rotor case machined into a substantially cup shape, and on its upper surface, a hub base 27 on which a disk hub is mounted, a drive pin 28 which engages with the disk hub to regulate the position, and a magnetic disk attracts the disk hub. A chucking mechanism including a chucking magnet 29 for A drive magnet 19 in which S poles and N poles are alternately magnetized is mounted inside the peripheral wall of the rotor case 22. Further, the rotary shaft 4 is erected at the center of the rotor case 22, and the rotary shaft 4, the rotor case 22, and the drive magnet 19 mainly constitute a rotor.

On the other hand, the through hole 10 is formed in the substrate 21 which is the fixed side.
The radial bearing 5 is fitted in the through hole 10. The radial bearing 5 has a shaft hole, and the rotary shaft is inserted into the shaft hole to support the rotor in the radial direction. A core 26, in which coils are wound around a plurality of salient poles, is fixed to the substrate 21 by a mounting screw 30, and the outer peripheral surface of each salient pole faces the drive magnet 19 at a predetermined interval. Further, on the outer side of the radial bearing 5, a thrust ball bearing 3 configured by sandwiching a plurality of balls 14 between thrust washers 23 and 24 (which will be described later in detail).
The thrust ball bearing 3 supports the load in the thrust direction of the rotor. And
When a predetermined drive current is applied to the coil 2-1, a magnetic interaction occurs between the salient poles of the core 26 and the drive magnet 19 to rotate the rotor.

As the substrate 21, a magnetic substance such as iron or a resin substance such as phenol or glass epoxy is used, and a circuit wiring pattern is formed on the surface thereof. The radial bearing 5 is composed of a sintered oil-impregnated bearing formed by sintering metal powder.

FIG. 2 is an enlarged view of the vicinity of the broken line indicated by the arrow in FIG. In FIG. 2, the plurality of balls 14 of the thrust ball bearing 3 are rotatably held by the retainer 11. Grease (not shown) is applied to the periphery of each ball 14 so that each ball 14 can smoothly rotate. An annular lower thrust washer 24 is placed on the substrate 21, and the balls 14 held by the retainer 11 are in contact with the lower thrust washer 24. Furthermore, an annular upper thrust washer 23 is provided above the ball 14 so as to abut. The load of the rotor is applied to the ball 14 through the upper thrust washer 23.
The thrust ball bearing as a whole supports the load.

The lower thrust washer 24 of the thrust ball bearing 3 has a flat plate portion 24a which is placed on the base plate 21 and abuts on the ball 14, and a rising portion 24b which rises in the thrust direction from the inner edge of the flat plate portion 24a. When it has a cylindrical shape, it is referred to as a cylindrical portion) and a collar-shaped portion 24c bent from the tip of the standing portion 24b to the radial bearing 5 side. The standing portion 24b connected to the flat plate portion 24a and the collar-shaped portion 24c. The bearing holding portion 25 is configured with the portion 24c. And
The bearing holding portion 25 is configured to hold the radial bearing 5 together with the substrate 21. Especially, lower thrust washer 2
Since 4 is formed by, for example, compositionally deforming a metal plate or molding a resin, the bearing holding portion 25
Has some elasticity. This elastic force allows the radial bearing to be held more firmly.

The radial bearing 5 has a flange portion 5a having a diameter larger than that of the portion fitted into the through hole 10 of the substrate 21, one end surface of the flange portion 5a abuts on the substrate 21, and the other end surface thereof is a lower thrust. The washer 24 is in contact with the collar-shaped portion 24c. That is, the flange portion 5 a is sandwiched between the substrate 21 and the bearing holding portion 25.

The flange portion 5a is connected to the substrate 21 and the bearing holding portion 2.
When the substrate 21 is made of a magnetic material such as iron, the force sandwiched between the rotor 5 and the drive magnet 19 causes the rotor load to be increased by the attraction force directly acting between the substrate 21 and the drive magnet 19. , Lower thrust washer 24, substrate 21
As a result, the bearing holding portion 25 of the lower thrust washer 24 is also urged downward to hold the flange portion 5a of the radial bearing 5 therebetween. When the substrate 21 made of resin such as phenol or glass epoxy is used, the load of the rotor is increased by the attraction force acting between the core and the drive magnet 19 because the core is fixed by the mounting screw. Thrust washer 23, ball 14, lower thrust washer 24, substrate 2
The flange portion 5 of the radial bearing 5 is transmitted sequentially in one direction.
It sandwiches a. By attaching a magnetic material to the surface of the substrate facing the drive magnet, the substrate is made of a non-magnetic member,
For example, a strong suction force can be formed even with a phenol substrate. In this case, the same action and effect as when the substrate 21 is made of a magnetic material are obtained.

Therefore, the connection between the through hole 10 opened in the frame and the radial bearing 5 can be achieved simply by inserting the flange portion 14 of the radial bearing into the corresponding portion of the through hole 10 without caulking or the like. That is, when the substrate 21 is made of a magnetic material such as iron, the radial bearing 5 is held by the magnetic force of the drive magnet 19 and the substrate 21. In addition, since the radial bearings 5 and 21 can be easily disengaged by applying a force equal to or greater than the suction force against the holding, the radial bearing 5 and the substrate 21 can be easily disassembled. That is, a partial repair of the motor, for example, replacement of the board 21 can be easily performed.

Although the circumferentially opposed motor in which the drive magnet and the stator core are opposed to each other on the circumferential surface of the rotor case has been described in the drawing, the same action and effect can be obtained even when used in the surface opposed motor shown in FIG.

[0019]

EXAMPLE FIG. 3 is a perspective view showing the shape of a lower thrust washer, FIG. 3 (a) shows one example thereof, and FIGS. 3 (b) and 3 (c) show another example. Descriptions that overlap with the above-mentioned conventional example will be omitted.

In FIG. 3A, the lower thrust washer 24
-1 has an annular cylindrical portion 24b, and the cylindrical portion faces an inner peripheral surface of a retainer (not shown). For this reason, the grease scattered from the thrust ball bearing may not be absorbed by the cylindrical portion 24b.
It is possible to prevent the particles from being scattered in the rotation axis direction by being blocked by. Further, since the amount of grease scattered from the thrust ball bearing is reduced, the amount of grease is preserved for a long time, the slidability is stabilized, and the life is extended.

FIG. 3B shows a lower thrust washer 24-2.
In this embodiment, an annular standing portion 24d is provided on the annular outer peripheral surface of the flat surface portion 24a so that grease scattered from the thrust ball bearing 3 can be prevented also at the standing portion 24d. By providing such a standing portion 24d,
It is possible to prevent the grease scattered from the thrust ball bearing 3 from being blocked by the standing portion 24d and scattered in the arrow core direction. That is, the grease scattered from the thrust ball bearing described in FIG.
It is possible to prevent the oil from being blocked by b and scattering in the direction of the rotation axis, and also to prevent scattering in the direction of the arrow core as described above. Therefore, the grease amount of the thrust ball bearing is further preserved for a long period of time. be able to.

In FIG. 3 (c), the lower thrust washer 24
-3, the upright portion 24b that rises vertically from the flat surface portion 24a to the inner peripheral side is partially upright from the flat surface portion 24a, and the extended collar-shaped portion 24c communicates with the upright portion 24b and is located on the radial bearing side. Is bent to. In the case of the figure, the upright portions 24b are provided at two locations facing the central portion of the washer, but a plurality of the above-mentioned two or more locations can be provided.

[0023]

As described above, the lower thrust washer of the thrust ball bearing is provided with the bearing holding portion to serve as the bearing holding portion, and the radial bearing is held between the bearing holding portion and the substrate to open in the frame. It is not necessary to fix the radial bearing to the through hole by crimping.
That is, it is possible to provide a motor structure in which an excessive force is applied to a part of the radial bearing due to caulking or the like to damage the radial bearing or the distortion does not deteriorate the flatness of the frame. As a result, the motor can be partially repaired, resulting in a highly economical spindle motor.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment in which the present invention is applied to a spindle motor.

2 is an enlarged view within the broken line indicated by the arrow of the present invention shown in FIG.
It is a figure explaining the mechanism which hold | maintains to the radial bearing the board | substrate which has not been crimped.

FIG. 3 is a view showing the shape of a lower thrust washer of the present invention.

FIG. 4 is a sectional view of a conventional example showing one aspect of a spindle motor.

[Explanation of symbols]

 3 Thrust Ball Bearing 4 Rotating Shaft 5 Radial Bearing 11 Retainer 14 Ball 22 Rotor Case 23 Upper Thrust Washer 24 Lower Thrust Washer 24a Flat Surface 24b Standing Part (Cylindrical Part) 24c Collar 24d Standing Part 25 Bearing Holding Part

Claims (3)

[Claims] 1. A rotor having a rotating shaft and a drive magnet, a radial bearing for supporting the rotor in the radial direction, and a thrust ball bearing for supporting the rotor in the thrust direction and having balls and thrust washers. And a substrate on which the radial bearing is mounted, and a thrust washer of the thrust ball bearing provided on the substrate side has a bearing holding portion that is bent toward the radial bearing side. A spindle motor, wherein a holding portion holds the radial bearing in cooperation with the substrate. 2. The thrust ball bearing has a retainer for holding a ball, the bearing holding portion has an annular cylindrical portion, and the cylindrical portion faces an inner peripheral surface of the retainer. The spindle motor according to claim 1, which is characterized in that. 3. The spindle motor according to claim 1, wherein the substrate is made of a magnetic material, and the drive magnet is magnetically attracted to the substrate side.