JP3208042B2 - Disk drive motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive motor applicable to a magnetic disk drive, an optical disk drive and the like.

[0002]

2. Description of the Related Art Floppy disk drive, CD-R
FIGS. 7 and 8 show a conventional example of a disk drive motor used in an OM drive device or the like. In FIG. 7, a cylindrical bearing holder 4 is disposed substantially at the center of the motor substrate 1, and an appropriate number of projections 4 e formed on the lower end surface of the bearing holder 4 are fitted into holes of the substrate 1. The bearing holder 4 is fixed to the substrate 1. A stator core 5 composed of a laminated core is fitted on the outer peripheral side of the bearing holder 4.
And is fixed to the bearing holder by appropriate fixing means such as set screws. The stator core 5 has an appropriate number of salient poles radially, and a driving coil 6 is wound around each salient pole.

A thrust bearing 7 is arranged on the motor substrate 1 on the inner peripheral side of the bearing holder 4, and the lower half of the thrust bearing 7 is fitted into a hole of the motor substrate 1 so that the thrust bearing 7 is mounted on the motor substrate 1. It is fixed to the substrate 1. Radial bearings 9 and 8 each composed of a sintered oil-impregnated bearing are fixed on the inner peripheral side of the bearing holder 4 by press fitting.
The rotating shaft 12 is inserted into the inner peripheral sides of the bearings 9 and 8, and the lower end, which is one end of the rotating shaft 12, is in contact with the upper surface of the thrust bearing 7. The rotating shaft 12 is rotatably supported by radial bearings 9 and 8, and a thrust bearing 7 supports a load in the thrust direction.

The rotating shaft 1 protruding from the upper end of the bearing holder 4
The center of a cup-shaped and folded-down rotor case 10 is fitted and fixed to the upper end of the rotor case 2. Rotor case 10
On the inner surface side of the peripheral wall, a rotor magnet 11 that is magnetized in a ring shape and alternately N-pole and S-pole alternately at a constant interval in the circumferential direction is fixed. The inner peripheral surface of the rotor magnet 11 and the distal end surface of each salient pole, which is the outer peripheral surface of the stator core 5, face each other with an appropriate gap. Therefore, the rotor magnet 11
By controlling the energization of each drive coil 6 according to the rotational position of the rotor, the rotor magnet 11 is urged in the rotational direction by the magnetic attraction and repulsion between the salient poles and the magnetic poles of the rotor magnet 11, and The rotor case 10 is driven to rotate together with the magnet 11. Although not shown in FIG. 7, a hub or a turntable for supporting the disk is attached substantially integrally with the rotating shaft 12 and the rotor case 10 so that the disk is driven to rotate together with the rotating shaft 12 and the rotor case 10. Has become.

[0005] The motor substrate 1 is fixed to a chassis of a disk drive main body (not shown), and includes a magnetic head and an optical pickup provided on the disk drive main body side and a rotating shaft 12 for controlling the position of the disk. In order to regulate the positional relationship, the motor substrate 1 is provided with a reference hole 2 serving as a reference for attaching to the chassis of the disk drive device main body.

[0006] In the conventional example shown in FIG.
7 is different from the conventional example shown in FIG. 7, but is basically the same as the conventional example shown in FIG. 7; therefore, members corresponding to the members of the conventional example shown in FIG. The description will focus on the components different from the examples. In FIG.
Mounting screw 20 penetrating through stator core 5 and bearing holder 4
Are screwed into the motor substrate 1 so that the stator core 5 and the bearing holder 4 are fixed on the motor substrate 1. A disk-shaped thrust bearing 7 is inserted into the bearing holder 4 and is mounted on the motor substrate 1. The lower end of the rotating shaft is in contact with this thrust bearing. The center of the rotor case 10 is integrally fixed and the upper end of the rotating shaft 12 protruding from the upper end surface of the rotor case 10 includes:
A disk clamp 15 having a turntable 14 and the like is attached. The illustrated disk clamp unit 15 is a compact disk (hereinafter referred to as “CD”) or C
It is compatible with a D-ROM, and is designed to rotate a disk by pressing it onto a turntable 14 using magnetic attraction.

[0007]

As already explained,
In a conventional disk drive motor, the motor substrate 1 is fixed to a chassis of the disk drive main body with reference to a reference hole provided in the motor substrate 1 so that a magnetic head or an optical disk provided on the disk drive main body side is provided. The positional relationship between the read / write head such as a pickup and the rotary shaft 12 is regulated. However, a dimensional error between the reference hole of the motor substrate 1 and the mounting position of the bearing holder 4, a deviation between the center of the outer diameter and the center of the inner diameter of the bearing holder 4, and a molding error of the bearings 8 and 9 are accumulated. There has been a drawback that the positional relationship between the read / write head provided on the disk drive device main body side and the rotary shaft tends to be shifted.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem of the prior art, and by improving the accuracy of the relative positional relationship between a motor substrate and a rotating shaft, it is possible to read and write data on a disk drive main body. It is an object of the present invention to provide a disk drive motor capable of improving the relative positional accuracy between a head for use and a rotating shaft.

[0009]

According to the first aspect of the present invention,
In a disk drive motor in which one end of the rotating shaft of the motor contacts the thrust bearing and the rotating shaft is rotatably supported by the radial bearing, the thrust bearing is large.
Having a diameter portion and a small diameter portion, and an outer peripheral surface of the large diameter portion and the small diameter portion.
Each form a reference surface, the outer peripheral surface of the large-diameter portion and the inner peripheral surface of the radial bearing are fitted, and the radial bearing is mounted with reference to the outer peripheral surface of the large-diameter portion of the thrust bearing.
The plate is provided with a reference portion for attachment to the chassis, a reference recess for attaching a thrust bearing is provided at a predetermined position from the attachment reference portion, and a thrust bearing is provided in the reference recess.
Characterized in that the outer peripheral surface of the small diameter portion is fitted .

[0010] As the invention of claim 2, wherein the radial bearing includes a diameter of the inner circumferential surface of the part thrust bearing is fitted, has good and diameter of the bearing surface that supports the rotation shaft even in the same .

[0011]

According to the present invention, the load applied to the rotating shaft of the motor is supported by the thrust bearing, and the rotating shaft is rotatably supported by the radial bearing. By fitting the outer peripheral surface of the thrust bearing and the inner peripheral surface of the radial bearing, the inner peripheral surface of the radial bearing is attached with reference to the outer peripheral surface of the thrust bearing. It will be attached as a reference.
A thrust bearing is provided in the reference recess provided on the motor board.
Is mounted on the outer peripheral surface of this thrust bearing and radial
When the inner peripheral surface of the bearing is fitted, the thrust bearing
Radial bearings can be mounted based on the outer peripheral surface.
Therefore, the rotating shaft can also be attached with reference to the reference recess.
Will be.

[0012] As inventions of claim 2, wherein, of the radial bearing, the diameter of the inner peripheral surface of the part thrust bearing is fitted, if the same as the diameter of the bearing surface for supporting the rotary shaft, a thrust bearing By fitting the outer peripheral surface of the shaft and the inner peripheral surface of the radial bearing, the rotating shaft is directly positioned on the outer peripheral surface of the thrust bearing, further improving the relative positional accuracy between the motor substrate and the rotating shaft. Can be done.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a disk drive motor according to the present invention will be described below with reference to the drawings. In addition,
The same components as those of the conventional example shown in FIGS. 7 and 8 are denoted by the same reference numerals. In FIG. 1, a mounting reference hole 2 serving as a reference portion for mounting the motor substrate 1 to a chassis 3 of a disk drive main body is provided at a predetermined position on the outer peripheral side of the motor substrate 1. A reference hole 1a serving as a reference recess for mounting a thrust bearing is provided in a substantially central portion of the motor board 1 at a position separated from the mounting reference hole 2 by a predetermined dimension in a predetermined direction. This reference hole 1
The lower half of the thrust bearing 7 composed of the upper half of the large diameter and the lower half of the small diameter is fitted and fixed to a.

A cylindrical bearing holder 4 is arranged on the motor board 1 on the outer peripheral side of the thrust bearing 7. Radial bearings 9 and 8 each composed of a sintered oil-impregnated bearing are fixed on the inner peripheral side of the bearing holder 4 by press fitting.
These radial bearings 9 and 8 have the same outer diameter and inner diameter, are press-fitted into the inner peripheral side of the bearing holder 4 in advance, and the inner diameters of the radial bearings 9 and 8 are outside the upper half of the thrust bearing 7. It is the same as the diameter. When the bearing holder 4 is disposed on the motor board 1, the inner peripheral surface of the lower radial bearing 8 and the outer peripheral surface of the upper half of the thrust bearing 7 are fitted. The radial bearing 8 is mounted on the basis of the outer peripheral surface.

A stator core 5 composed of a laminated core is fitted on the outer peripheral side of the bearing holder 4, and the stator core 5 is mounted on a flange formed at the lower end of the bearing holder 4. The stator core 5 and the bearing holder 4 are fixed to the motor substrate 1 by an appropriate fixing means, for example, by screwing a set screw passing through the stator core 5 and the bearing holder 4 into the motor substrate 1. However, as a result of the radial bearing 8 being mounted on the basis of the thrust bearing 7 as described above, the bearing holder 4, the radial bearing 9,
The stator core 5 is also mounted on the basis of the thrust bearing 7. The stator core 5 has an appropriate number of salient poles radially, and a driving coil 6 is wound around each salient pole.

A rotary shaft 12 is inserted into the inner peripheral sides of the bearings 9 and 8, and a lower end, which is one end of the rotary shaft 12, is in contact with the upper surface of the thrust bearing 7. The rotating shaft 12 is rotatably supported by radial bearings 9 and 8, and a thrust bearing 7 supports a load in the thrust direction.
A central portion of a cup-shaped and folded rotor case 10 is fitted and fixed to the upper end of the rotating shaft 12 protruding from the upper end of the bearing holder 4. On the inner surface side of the peripheral wall of the rotor case 10, an N pole and an S pole are
A pole magnetized rotor magnet 11 is fixed. The inner peripheral surface of the rotor magnet 11 and the stator core 5
Is opposed to the distal end surface of each salient pole, which is the outer peripheral surface, with an appropriate gap. Therefore, if the energization of each drive coil 6 is switched and controlled in accordance with the rotational position of the rotor magnet 11, the rotor magnet 11 is rotated in the rotational direction by the magnetic attraction between the salient poles and the magnetic poles of the rotor magnet 11. The rotor case 10 is energized and
Is driven to rotate. Although not shown in FIG. 1, a hub or a turntable for supporting the disk is attached substantially integrally with the rotating shaft 12 and the rotor case 10, and the disk is driven to rotate together with the rotating shaft 12 and the rotor case 10. ing.

In the disk drive motor constructed as described above, the mounting reference hole 2 of the motor substrate 1 and the projection provided at a predetermined position of the chassis 3 of the disk drive main body are fitted to each other. By screwing a mounting screw 13 positioned at a predetermined position of the chassis 3 and inserted into the motor board 1 into a screw hole of the chassis 3, the chassis 3
Fixed to Therefore, the magnetic head or the optical pickup head on the chassis 3 can be accurately aligned with the rotation center of the motor.

According to the embodiment described above, the inner peripheral surface of the radial bearing 8 and the outer peripheral surface of the thrust bearing 7 are fitted to each other, whereby the radial bearing 8 is attached with reference to the outer peripheral surface of the thrust bearing 7. Therefore, the radial bearing 9 held by the bearing holder 4 which is substantially integral with the radial bearing 8 is also mounted on the basis of the outer peripheral surface of the thrust bearing 7, and these radial bearings 8,
As a result, the rotating shaft 12 rotatably supported by the bearing 9 is also supported with reference to the outer peripheral surface of the thrust bearing 7. Therefore, the relative positional accuracy between the motor substrate 1 and the rotating shaft 12 can be improved only by controlling the positional accuracy of the thrust bearing 7 in the motor substrate 1.

Further, according to the above embodiment, the hole 1a serving as a reference for mounting the thrust bearing is provided.
Since a is provided at a position separated by a predetermined dimension in a predetermined direction from the reference hole 2 serving as a reference portion for mounting the disk drive device body to the chassis 3, the outer peripheral surface of the thrust bearing 7 mounted in the hole 1a is provided. The rotary shaft 12 supported on the basis of the above has a good relative positional accuracy even in relation to the chassis 3 of the disk drive main body, and the relative positional accuracy between the read / write head and the rotary shaft 12 on the disk drive main body side. Will also be higher.

Next, various modified embodiments of the present invention will be described. Note that the same reference numerals are used for components corresponding to the components of the embodiment shown in FIG. 1, and portions different from those of the embodiment shown in FIG. 1 will be mainly described. In FIG. 2, a reference hole 1a serving as a reference recess for attaching a thrust bearing is provided substantially at the center of the motor substrate 1. A lower half 7a of a thrust bearing 7 composed of a large-diameter upper half 7b and a small-diameter lower half 7a is fitted into and fixed to the reference hole 1a. A radial bearing 18 also serving as a core holder is arranged on the outer peripheral side of the thrust bearing 7 on the motor board 1. The radial bearing 18 is made of a sintered oil-impregnated bearing, and is entirely formed in a relatively long cylindrical shape, and the entire inner peripheral surface is formed to have the same diameter as the outer diameter of the thrust bearing 7. The outer peripheral surface of the thrust bearing 7 and the inner peripheral surface of the radial bearing 18 are fitted, and the radial bearing 18 is attached with reference to the outer peripheral surface of the thrust bearing 7.

The center hole of the stator core 5 is fitted to the outer peripheral side of the radial bearing 18, and the fixing core 20 is screwed into the motor substrate 1 through the flange of the stator core 5 and the radial bearing 18, thereby fixing the stator core 5. At the same time, the radial bearing 18 is fixed on the motor substrate 1 while being positioned by the thrust bearing 7 as described above. The rotating shaft 1 is provided on the inner peripheral surface side of the radial bearing 18.
2 is inserted and the lower end of the rotating shaft 12 abuts on the upper surface of the radial bearing 7 so that the load applied to the rotating shaft 12 is supported by the radial bearing 7 and the rotating shaft 12 is rotatably supported by the radial bearing 18. ing.

The center of the rotor case 10 is integrally fixed to the rotating shaft 12 projecting from the upper end of the radial bearing 18 and the rotating shaft 12 projecting from the upper end surface of the rotor case 10.
A disk clamp 15 having a turntable 14 and the like is attached to the upper end of the disk. The illustrated disk clamp unit 15 is adapted to a CD or a CD-ROM, and is configured to press the disk onto the turntable 14 using magnetic attraction and to rotate the disk.
The rotor case 10 has a cup-shaped shape,
A ring-shaped rotor magnet 11 is fixed to the inner surface of the peripheral wall. The inner peripheral surface of the rotor magnet 11 and the distal end surface of each salient pole, which is the outer peripheral surface of the stator core 5, face each other with an appropriate gap. Therefore, the rotor magnet 11
By controlling the energization of each drive coil 6 according to the rotational position of the rotor, the rotor magnet 11 is urged in the rotational direction by the magnetic attraction and repulsion between the salient poles and the magnetic poles of the rotor magnet 11, and The rotor case 10, the rotating shaft 12, and the disk clamp unit 15 are rotationally driven together with the magnet 11, and the disk mounted and clamped on the disk clamp unit 15 is rotationally driven.

According to the embodiment shown in FIG. 2 described above,
Since the inner peripheral surface of the radial bearing 18 and the outer peripheral surface of the thrust bearing 7 are fitted to each other and the radial bearing 18 is attached with reference to the outer peripheral surface of the thrust bearing 7, the radial bearing 18 is rotatably supported by the radial bearing 18. Rotating shaft 12
Are also supported on the basis of the outer peripheral surface of the thrust bearing 7. Therefore, the relative positional accuracy between the motor substrate 1 and the rotating shaft 12 can be improved only by controlling the positional accuracy of the thrust bearing 7 in the motor substrate 1. In addition, since the diameter of the inner peripheral surface of the radial bearing 18 is the same as the diameter of the bearing surface that rotatably supports the rotating shaft 12, the inner peripheral surface of the radial bearing 18 fitted to the outer peripheral surface of the thrust bearing 7 In addition, the inner peripheral surface of the radial bearing 18 supporting the rotating shaft 12 can be commonly worked as a common surface, and as a result, the position of the rotating shaft 12 is directly regulated by the thrust bearing 7. , Motor board 1 and rotating shaft 12
And the relative positional accuracy with respect to.

The thrust bearing and the radial bearing may be configured as shown in FIGS. The example shown in FIG. 3 is that the lower half 7a of the thrust bearing 7 composed of the large-diameter upper half 7b and the small-diameter lower half 7a is fitted and fixed in the reference hole 1a of the motor board 1. Same as the embodiment,
A radial bearing 18 also serving as a core holder is arranged on the outer peripheral side of the thrust bearing 7 on the motor board 1. The inner peripheral surface of the radial bearing 18 has an upper half 7 b of the thrust bearing 7.
The radial bearing 18 is mounted on the outer peripheral surface of the radial bearing 18 with reference to the outer peripheral surface of the thrust bearing 7. The surface of the radial bearing 18 to be fitted to the thrust bearing 7 should be in sliding contact with the rotating shaft 12. The surface 18a has a larger diameter than the inner peripheral surface. According to this embodiment, by fitting the large-diameter surface 18a of the radial bearing 18 with the outer peripheral surface of the thrust bearing 7, the radial bearing 18 is attached with reference to the outer peripheral surface of the thrust bearing 7. The same operation and effect as in the example are achieved.

In the embodiment shown in FIG. 4, the thrust bearing 7 is
A small diameter portion 7a at the lower portion, a large diameter portion 7b at the middle portion, and a small diameter portion 7c at the upper portion, and the small diameter portion 7a is fitted and attached to a reference hole 1a as a reference concave portion of the motor substrate 1;
The outer peripheral surface of the large-diameter portion 7b is fitted to the large-diameter surface 18a of the inner periphery at the lower end of the radial bearing 18, and the outer peripheral surface of the small-diameter portion 7c is shared with the sliding surface of the radial bearing 18 on the rotating shaft 12. It is fitted on the inner peripheral surface. In addition, any one of between the outer peripheral surface of the large-diameter portion 7b and the large-diameter surface 18a of the inner periphery of the lower end of the radial bearing 18 or between the outer peripheral surface of the small-diameter portion 7c and the inner peripheral surface of the radial bearing 18 There can be a gap on either side. In any case, the same operation and effect as those of the above embodiment can be obtained.

In the embodiment shown in FIG. 5, an appropriate number of projections 7d are provided on the lower end surface of the thrust bearing 7, and these projections 7d are fitted and attached to a reference hole 1b as a reference recess of the motor substrate 1, and The bearing 7 has an intermediate large-diameter portion 7b and an upper small-diameter portion 7c, and the large-diameter portion 7b is provided with a gap between the large-diameter surface 18a on the inner periphery of the lower end of the radial bearing 18. At the same time, the outer peripheral surface of the small-diameter portion 7c is fitted to the common inner peripheral surface with the sliding contact surface of the rotary shaft 12 of the radial bearing 18, and the radial bearing is referenced to the outer peripheral surface of the small-diameter portion 7c of the thrust bearing 7. 18 is attached to the motor substrate 1. This embodiment also has the same operation and effect as the above embodiment.

In the embodiment shown in FIG. 6, the thrust bearing 7 has a cylindrical main body portion 7e and a flange portion 7f on the lower end side. The flange 7f is brought into contact with the lower surface of the motor substrate 1 by fitting from the side, the inner peripheral surface of the radial bearing 18 is fitted to the outer peripheral surface of the main body portion 7e, and the outer peripheral surface of the thrust bearing 7 is referenced. And a radial bearing 18 attached thereto. The inner peripheral surface of the radial bearing 18 is formed to have the same diameter as a whole, and the inner peripheral surface of the radial bearing 18 fitted to the outer peripheral surface of the thrust bearing 7 and the radial bearing 1 in which the rotary shaft 12 slides.
8 has the same diameter as the inner peripheral surface. This embodiment also has the same operation and effect as the above embodiment.

[0028]

According to the first aspect of the present invention, the inner peripheral surface of the radial bearing and the outer peripheral surface of the thrust bearing are fitted, whereby the radial bearing is mounted on the basis of the outer peripheral surface of the thrust bearing. As a result, the rotating shaft rotatably supported by the radial bearing is also supported with reference to the outer peripheral surface of the thrust bearing as a result, and it is only necessary to manage the positional accuracy of the thrust bearing on the motor board. , Ru can increase the relative positional relationship between the accuracy of the motor substrate and the rotary shaft. As a result, the accuracy of the relative positional relationship between the read / write head on the disk drive device main body side to which the motor substrate is attached and the rotating shaft can be increased. In addition, a reference recess for mounting the thrust bearing is provided,
This reference recess is formed in the chassis of the disk drive unit body.
Because it is provided at a predetermined position from the mounting reference part,
The outer peripheral surface of the thrust bearing attached to the reference recess
The rotating shaft supported on the basis is the main body of the disk drive unit.
The relative position accuracy is high in relation to the chassis of
Relative position between read / write head and rotary shaft on drive unit
Relationship accuracy can be improved.

[0029]

According to the second aspect of the present invention, the diameter of the inner peripheral surface of the radial bearing on which the thrust bearing is fitted is made equal to the diameter of the bearing surface for rotatably supporting the rotating shaft. An inner peripheral surface of the radial bearing fitted with the outer peripheral surface,
The inner peripheral surface of the radial bearing that supports the rotating shaft can be processed in common as a common surface, and as a result, the position of the rotating shaft is directly regulated by the thrust bearing, and the motor substrate and the rotating Position accuracy relative to the axis can be further improved.

[Brief description of the drawings]

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

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

FIG. 3 is a sectional view showing a modified example of a thrust bearing and a radial bearing applicable to the present invention.

FIG. 4 is a sectional view showing another modified example of a thrust bearing and a radial bearing applicable to the present invention.

FIG. 5 is a sectional view showing still another modified example of a thrust bearing and a radial bearing applicable to the present invention.

FIG. 6 is a sectional view showing still another modified example of a thrust bearing and a radial bearing applicable to the present invention.

FIG. 7 is a sectional view showing an example of a conventional disk drive motor.

FIG. 8 is a sectional view showing another example of the conventional disk drive motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motor board 2 Mounting reference part 3 Chassis 7 Thrust bearing 8 Radial bearing 9 Radial bearing 12 Rotary shaft 18 Radial bearing 1a Reference recess

Claims (2)

(57) [Claims] 1. A disk drive motor in which one end of a rotating shaft of a motor abuts a thrust bearing and the rotating shaft is rotatably supported by a radial bearing, wherein the thrust bearing has a large diameter portion, a small diameter portion, Have these
The outer peripheral surfaces of the large diameter portion and the small diameter portion form reference surfaces, respectively, and
And the outer peripheral surface and the inner peripheral surface of the radial bearing of the large diameter portion is fitted, the radial bearing is mounted relative to the large diameter portion outer peripheral surface of the thrust bearing, the motor substrate mounting reference portion of the chassis Provided
Is a reference recess for the thrust bearing mounting is provided on this from the mounting reference portion at a predetermined position, above the reference recess
A disk drive motor, wherein an outer peripheral surface of a small diameter portion of a thrust bearing is fitted . 2. The radial bearing is fitted with a thrust bearing.
Diameter of the inner peripheral surface of the
Claim 1 disk drive motor described in the radial Ru same der.