JP2000100060A - Disk driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable spindle motor having the satisfied rotation al accuracy by partially providing a notch in a stator part which forms a stator of the spindle motor, and arranging so that the thrust receiving surface part of a thrust bearing for receiving the end surface of the spindle is formed to the tapered state so as to be high for the notched part of the stator, while formed so as to be lowered for the opposite side. SOLUTION: A head 17 for recording/reproducing against a recording medium 9 and a carriage 16 are entered into the notched part constituted of five blocks, three blocks of which are notched. The thrust receiving surface part 50a is tapered in the height direction so as to be high at the side of head 17 in the direction of the notched part of the stator 40 and to be lowered at the opposite side which is the side of stator 40 furnished with teeth. By means of forming the thrust receiving surface part 50a of the thrust bearing 50 to the tapered state, the height of the spindle 3 is easily adjustable at the time of assembling, then the accuracy in the height of the recording medium 9 is stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle motor mounted on, for example, an optical or magnetic disk drive for rotating a recording disk.

[0002]

2. Description of the Related Art FIG.
FIG. 1 is a cross-sectional view illustrating a conventional disk drive device disclosed in the official gazette. In the figure, reference numeral 11 denotes a chassis for supporting the entire disk drive, and a caulking claw 11a is formed on the bottom surface of the chassis 11. A flange 12a formed on the outer periphery of the shaft holder 12 is fixed to the claw 11a. Also, the bottom 12b of the shaft holder 12
, A bearing member 13 is fixedly mounted.
Consists of a receiving plate 13a and a thrust plate 13b fixed to the center of the receiving plate 13a. Receiving plate 1
3a is caulked and fixed to the bottom portion 12b.

Reference numeral 3 denotes a spindle shaft. The spindle shaft 3 is supported in a radial direction by a radial bearing 4 in the shaft holder 12, and an end 3a of the spindle shaft 3 formed on a spherical surface is used as the bearing member 1.
The thrust direction is supported by the third thrust plate 13b. Reference numeral 9 denotes a recording disk, and 8 denotes a hub for holding the recording disk 9, which is fixed to the spindle shaft 3. The magnet 7 on the ring is fixed to the lower surface of the hub 8 via a yoke 14. The coil 6 is disposed on the wiring board 15 so as to face the magnet 7, and the wiring board 15 is fixed on the upper surface of the chassis 11.

Next, the operation will be described. When a current is applied to the coil 6, a driving force is generated in the magnet 7 by the magnetic field of the magnet 7 and the current flowing through the coil 6. As a result, the hub 8 to which the magnet 7 is fixed and the spindle shaft 3 rotate around the spindle shaft 3. The end 3a of the spindle shaft 3 is supported by the thrust plate 13b of the bearing member 13 by the attractive force between the magnet 7 and the chassis 11, and rotates while being supported by the radial bearing 4 in the radial direction.

[0005]

Since the conventional disk drive is constructed as described above, if the dimensions of the mounted components such as the shaft holder 12, the spindle shaft 3 and the like vary, the height of the recording disk 9 is increased. Variations increase depending on the size of each component. Therefore, the height accuracy of the recording disk 9 deteriorates, and the contact state between the recording disk and the head becomes inevitably inevitable, which impairs the reliability of signal recording and reproduction. On the other hand, in order not to impair the reliability of the signal, the dimensional accuracy of each component must be increased, which leads to an increase in the cost of the component.

The present invention has been made to solve the above problems, and has as its object to obtain a low-cost and highly reliable disk drive.

[0007]

According to a first aspect of the present invention, there is provided a disk drive device comprising: a chucking portion for positioning a magnetic disk accommodated in a case; a spindle motor for rotating the magnetic disk; In a disk drive device including a spindle that is a rotation shaft of the spindle motor and a thrust bearing that supports a thrust direction of the spindle, the spindle motor has a stator as a stator having a notch, The thrust bearing has a taper shape in which the thrust receiving surface portion receiving the end face of the spindle is higher when the notch of the stator is notched and lower on the opposite side.

According to a second aspect of the present invention, in the disk drive device, the thrust bearing is configured to be movable in the same direction as the direction in which the thrust receiving surface has a tapered inclination, and the spindle is moved in the thrust direction. Is adjustable.

According to a third aspect of the present invention, in the disk drive device, the thrust bearing is configured such that a movable range of the thrust bearing is within a range in which the spindle always applies a pressure to the thrust receiving surface. It is a thing.

According to a fourth aspect of the present invention, there is provided a disk drive, wherein a hole for positioning a lever used for moving the thrust bearing in a horizontal direction is provided in a frame for supporting the entire disk drive. is there.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows Embodiment 1
2 is a partial cross-sectional plan view of the disk drive device as viewed from above, and FIG. 3 is a partial cross-sectional bottom view of the disk drive device as viewed from below. Also,
FIG. 1 is a cross-sectional view taken along the line AA shown in FIG. 3 and shows a state where a recording medium is mounted.

In FIG. 1, reference numeral 1 denotes a disk drive main body according to the present invention, 11 denotes a frame supporting the entire disk drive 1, and 9 denotes a recording medium.
1 and housed in a cartridge 92 composed of an upper case 92a and a lower case 92b. Reference numeral 20 denotes a spindle motor for driving the recording medium 9 to rotate.
0, a stator 40 and a coil 5. The rotor 30 includes a rotor magnet 31, a rotor yoke 32, a chucking portion 33 serving as a positioning unit for the recording medium 9, and a rotor 3 at the rotation center of the spindle motor 20.
The chucking portion 33 is constituted by a chucking magnet 33a for attracting the media hub 91 to the rotor 30 and a chucking pin 33b for positioning the media hub 91 in a plane direction. I have.

The stator 40 is composed of the coil 5 and the teeth 41 around which the coil 5 is wound, and a plurality of poles having at least one coil having at least the number of phases of the drive current as one block are arranged. . In the present embodiment, a spindle motor driven by three phases is shown. The number of coils is three, and the number of poles is constituted by three teeth 41 equal to the number of coils. Three teeth 41 form one block.

In this embodiment, the entire circumference is divided into eight blocks by the above-described blocks. However, three blocks are cut out and the cutout portion 44 is provided. The head 17 and the carriage 16 for recording / reproducing on / from the recording medium 9 enter the cutout portion 44. Notch 4
On the side of the rotor magnet 31 of No. 4, only the core portion 40a of the stator 40 is provided, and bridges the cutout portion 44. Even when the stator 40 lacks balance due to the core portion 40a, the spindle motor 20 has a small rotation fluctuation.
Can be obtained. Further, the stator 40 includes the rotor 3
0, which is a so-called inner rotor type spindle motor.

The stator 40 is positioned and fixed to a stator cover 43, and the stator cover 43 is positioned and fixed to the frame 11 in both the height and horizontal directions. FIG. 2 shows a state in which the cartridge 92 is not mounted in a cross-section in which a part of the stator cover 43 is cut away. Also, the stator cover 43
When the cartridge 92 is inserted into the disk drive 1, the cartridge 92
To protect the coil 5 from breaking.

Reference numeral 4 denotes a radial bearing that supports the spindle 3 in the radial direction, and is fixed to the frame 11 by caulking or the like. Reference numeral 50 denotes a thrust bearing for supporting the spindle 3 in the height direction, and reference numeral 50a denotes a thrust receiving surface portion with which the spherical end 3a of the spindle 3 contacts. The spindle 3 is always pressurized in a downward direction due to the height relationship between the rotor magnet 31 and the stator 40, and the end 3a is always in contact with the thrust receiving surface 50a. The thrust receiving surface portion 50a has a tapered shape in the height direction.
The head 17 side is high in a certain direction, and the side where the teeth 41 of the stator 40 is located is low on the opposite side. Therefore, when the thrust receiving surface portion 50a receives the end portion 3a of the spindle 3, the spindle 3 is in the direction of the lower taper, that is, the direction in which it falls in the direction B in the drawing. Reference numeral 50b denotes an elongated hole of the thrust bearing 50, which is formed so that the direction in which the taper is inclined becomes longer. The thrust bearing 50 is fixed to the frame 11 by screws 7 inserted into the elongated holes 50b.

The spindle motor 20 also has a stator 4 disposed on the outer periphery of the rotor magnet 31.
0 is partially provided with the notch 44 on the head 17 side, so that when a current is applied to the coil 5, a driving force is generated in a portion with the teeth 41 than in the notch 44 without the teeth 41, The spindle 3 holds the teeth 41 and the rotor magnet 3 while the spindle motor 20 is rotating.
The tooth 41 is urged by the suction force of 1 in the direction in which the teeth 41 are present, that is, in the direction B in the drawing. In FIG. 1,
34 is an index magnet and 15 is a wiring board.

Next, the operation will be described. When a current is applied to the coil 5, a driving force is generated in the rotor magnet 31 by the magnetic field of the rotor magnet 31 and the current flowing through the coil 5. As a result, the rotor 30 to which the rotor magnet 31 is fixed and the spindle 3
Rotate around the axis. The spindle 3 has its end 3a supported by the thrust receiving surface 50a of the thrust bearing 50 by the attraction between the rotor magnet 31 and the stator 40.
In the radial direction, it rotates while being supported by the radial bearing 4.

As described above, according to the first embodiment, since the thrust receiving surface portion 50a of the thrust bearing 50 is tapered, the height of the spindle 3 can be easily adjusted during assembly. Height accuracy is stable,
A highly reliable disk drive can be obtained. In addition, since the height accuracy of the recording disk 9 is stabilized by adjusting the height at the time of assembly even if the dimensions of the mounted components vary, an inexpensive disk drive device can be provided without increasing the dimensional accuracy of each component. Can be obtained.

Further, the taper of the thrust receiving surface portion 50a of the thrust bearing 50 is higher when the notch portion 44 of the stator 40 is provided, and lower when the teeth 41 are provided on the opposite side. It is inclined in the direction. While the spindle motor 20 is rotating, the spindle 3 is urged by the attraction of the teeth 41 and the rotor magnet 31 in the direction in which the teeth 41 are located, that is, in the direction B in the drawing. Therefore, since the inclination of the thrust receiving surface portion 50a and the direction of the inclination of the spindle motor 20 are the same, the contact between the radial bearing 4 and the spindle 3 during the rotation is not loose and the rotation accuracy is high and the spindle motor has high reliability. 20 can be obtained.

Embodiment 2 FIG. In the first embodiment,
The inclination direction of the spindle 3 when the thrust bearing surface portion 50a of the thrust bearing 50 is tapered is the same as the direction urged by the attraction force of the rotor magnet 31 and the stator 40. An embodiment in which the height of the spindle 3 is adjusted by a thrust bearing 50 having the following configuration will be described. The second embodiment has the same structure as the first embodiment, and the description of the reference numerals and the structure described in the first embodiment is omitted here. 4 is a partial cross-sectional view when the height of the spindle 3 is adjusted at the highest position, FIG. 5 is an enlarged view of a main part of FIG. 4, and FIG. 6 is a part when the spindle 3 is the lowest. 7 is an enlarged view of a main part of FIG. 6. FIG. 8 is a bottom view of the apparatus main body 1 as viewed from the back.

In the figure, reference numeral 4 denotes a radial bearing which is fixed to the frame 11 by caulking or the like and supports the spindle 3 in the radial direction. Reference numeral 4a denotes a hook-shaped projection formed on the inner side surface of the bottom portion of the radial bearing.
It becomes a stopper for the thrust bearing when 0 is moved in the horizontal direction. In the thrust bearing 50, as described in the first embodiment, the thrust receiving surface portion 50a has a tapered shape, and the inclination direction of the taper is such that the inclination direction of the spindle 3 is applied by the attractive force of the rotor magnet 31 and the stator 40. It is the same as the direction of the force.

In the thrust bearing 50, a portion of the thrust receiving surface portion 50a is formed so as to have a step with respect to a mounting portion, and a hook portion of the step engages with the projection 4a of the radial bearing 4 to form a stopper. Perform the function of Reference numeral 50b denotes a long hole of the thrust bearing 50, and the long hole 50b
Arrow E in the figure coincides with the direction urged by the suction force of
This is a hole that can be moved only in the direction of. Since the thrust bearing 50 moves only in the direction indicated by the arrow E, the direction in which the taper of the thrust bearing 50 is inclined always changes the notch 44 of the stator 40 even if the thrust bearing moves.
Is higher, and the side with the teeth 41 on the opposite side is lower.

As shown in FIG. 8, the thrust bearing 50 is provided with two projections at right angles to the moving direction of the thrust bearing 50, and forms a recess between them. Reference numeral 60 denotes a lever for horizontally moving the thrust bearing 50. The lever 60 is inserted into a recess of the thrust bearing 50, has an actuating portion for horizontally moving the thrust bearing 50, and a projection serving as a fulcrum of its operation. Is not attached to the apparatus main body 1 and is used only when adjusting the thrust bearing 50. Reference numeral 11b denotes a hole provided on the back surface of the frame 11 for positioning the lever 60 by fitting the projection of the lever 60 when adjusting the thrust bearing 50 with the lever 60.

The height of the spindle 3 is adjusted by the lever 6
This is performed by horizontally moving the thrust bearing 50 using 0. The height adjustment range is shown in FIG. 4 in which the spindle 3 is at the highest position, and FIG. 6 is in the case of the lowest position.
In both cases, the thrust bearing 50 is moved in the directions of the arrows B and F, and the thrust bearing 50 and the inner side surface 4a of the radial bearing 4 are in a range where the thrust bearing 50 hits. In this range, a pressure is applied so that the spindle 3 always contacts the thrust bearing 50. Specifically, as shown in FIGS. 5 and 7, the distance C from the upper surface of the rotor magnet 31 to the upper surface of the stator 40 and the rotor magnet 31
C> D is always maintained in the relation of the distance D from the lower surface of the stator 40 to the lower surface of the stator 40. That is, the rotor magnet 31 is always attracted obliquely downward by the stator 40.

The thrust bearing 50 is fixed by a screw 7 while being positioned at a predetermined position at the time of assembling before the height adjustment of the spindle 3. The screw 7 can be forcibly moved in the direction of the arrow B or F by the lever 60 without loosening the screw 7, and the screw 7 does not have to be re-tightened after the height adjustment.

As described above, according to the second embodiment, the height of the spindle 3 can be adjusted because the thrust receiving surface portion 50a of the thrust bearing 50 is tapered.
The height accuracy of the recording disk 9 is stable, and a highly reliable disk drive can be obtained. In addition, since the height accuracy of the recording disk 9 is stabilized by adjusting the height even if the dimensions of the mounted components vary, it is possible to obtain an inexpensive disk drive without increasing the dimensional accuracy of each component. Can be done.

Further, since the thrust bearing 50 is structured to be movable only in the horizontal direction, the disk drive can be made thinner. Further, since the spindle 3 is configured to move in the thrust direction by moving the thrust bearing 50 in the horizontal direction, the workability of adjusting the height of the spindle 3 is improved, and a disk drive with high productivity can be obtained. I can do it. Further, the thrust bearing 50 can be moved in the horizontal direction only within a range where the spindle 3 always applies a pressure to the thrust receiving surface portion 50a of the thrust bearing 50. Workability at the time is improved, and a disk drive with high productivity can be obtained.

The horizontal movement direction of the thrust bearing 50 has the same direction as the direction urged by the attraction force of the rotor magnet 31 and the stator 40, that is, the inclination of the taper shape of the thrust receiving surface portion 50a. As a result, the urging direction of the spindle 3 is always constant, and a highly reliable disk drive with stable rotation accuracy can be obtained.

Also, since the thrust bearing 50 can be moved in the horizontal direction without loosening the screw 7 to which the thrust bearing 50 is fixed, the workability of adjusting the height of the spindle 3 is improved, and a highly productive disk drive device is provided. Obtainable. In addition, since a hole for positioning the lever 60 is provided on the back surface of the frame 11, it is easy to move the thrust bearing 50 in the horizontal direction using the lever 60, and a highly productive disk drive device can be obtained. I can do it.

[0031]

As described above, in the disk drive device according to the first aspect of the present invention, the thrust bearing has a thrust receiving surface portion for receiving an end surface of the spindle, and the stator has a partially cut-out stator. The notched part is higher and the opposite side is tapered so that the spindle always tilts in the direction of the notched part of the spindle motor stator. Since the direction of inclination by the receiving surface portion is the same, contact between the radial bearing and the spindle during rotation is stable, and a highly reliable spindle motor with high rotation accuracy can be obtained.

Further, in the disk drive device according to the second aspect, the thrust bearing is configured to be movable in the horizontal direction, and the spindle is moved in the thrust direction by moving the thrust bearing in the horizontal direction. In addition, the workability of adjusting the height of the spindle is improved, and a disk drive device with high productivity and a reduced thickness can be obtained.

According to a third aspect of the present invention, in the disk drive device, the thrust bearing can be moved in the horizontal direction only within a range in which the spindle always presses the thrust receiving surface of the thrust bearing. Therefore, in addition to improving the workability at the time of spindle height adjustment work and obtaining a highly productive disk drive device, the contact between the radial bearing and the spindle is stabilized while the spindle is rotating,
A highly reliable spindle motor with good rotation accuracy can be obtained.

In the disk drive device according to the fourth aspect, the thrust bearing can be slightly moved in the horizontal direction by using the lever without loosening the screw fixing the thrust bearing. The workability of adjustment is improved, and a disk drive with high productivity can be obtained.

[Brief description of the drawings]

FIG. 1 is an enlarged longitudinal sectional view of a main part of a disk drive device according to a first embodiment of the present invention.

FIG. 2 is a partial cross-sectional plan view of the disk drive device of FIG.

FIG. 3 is a partial cross-sectional bottom view of FIG. 2;

FIG. 4 is a partial vertical cross-sectional view when the spindle is highest when adjusting the height of the spindle.

FIG. 5 is an enlarged view of a main part of FIG. 4;

FIG. 6 is a partial vertical cross-sectional view when the spindle is lowered to the lowest when adjusting the height of the spindle.

FIG. 7 is an enlarged view of a main part of FIG. 6;

FIG. 8 is a bottom view of the apparatus main body according to the second embodiment.

FIG. 9 is a longitudinal sectional view showing a conventional disk drive.

[Explanation of symbols]

1 disk drive unit, 3 spindles, 4
Radial bearings, 5 coils, 9 recording media, 11 frames, 16 carriages, 17 heads, 20
Spindle motor, 30 rotor, 31 rotor magnet, 32 rotor yoke, 33 chucking section, 33a chucking magnet, 33b chucking pin, 40 stator, 40a core section,
41 teeth, 44 notch, 43 stator cover, 50 thrust bearing, 50a thrust receiving surface, 91 media hub, 92 cartridge,
92a Upper case, 92b Lower case.

Claims (4)

[Claims] 1. A chucking unit for positioning a magnetic disk housed in a case, a spindle motor for rotating and driving the magnetic disk, a spindle as a rotating shaft of the spindle motor, and a thrust direction of the spindle. In a disk drive device having a thrust bearing for supporting the spindle motor, the stator as a stator of the spindle motor has a cutout, and the thrust bearing has a thrust receiving surface portion for receiving an end face of the spindle. A disk drive device characterized in that it has a tapered shape in which a chipped portion is higher and the opposite side is lower. 2. The thrust bearing according to claim 1, wherein the thrust bearing is configured to be movable in the same direction as the direction in which the thrust receiving surface has a tapered inclination, and the movement of the spindle in the thrust direction is adjustable. The disk drive according to claim 1. 3. The thrust bearing according to claim 2, wherein the movable range of the thrust bearing is within a range in which the spindle always pressurizes the thrust receiving surface. Disk drive. 4. The disk drive according to claim 2, wherein a hole for positioning a lever used to move the thrust bearing in a horizontal direction is provided in a frame supporting the entire disk drive. .