JP2810250B2 - Disk drive - 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, and more particularly to a disk drive suitable for realizing a small, lightweight, thin and highly reliable disk drive .

[0002]

2. Description of the Related Art In recent years, there has been a demand for smaller and lighter and thinner laptop computers and portable notebook personal computers, and magnetic floppy disk devices and optical disk devices, which are external recording devices, have been reduced in size and weight.
There has been a demand for a reduction in thickness. On the other hand, as a recording medium of the recording device, there are a floppy disk using magnetism and an optical disk using magnetism and light or only light.
Floppy disks used in conjunction with the demand for miniaturization are in the direction of smaller diameters, and this has spurred further reduction in the size and weight of the apparatus.

As a representative example of the disk device, for example, an optical disk device is clearly shown in FIG. 1.2, “Basic Configuration of Optical Disk Memory,” on page 6 of “Optical Disk Technology” published by Radio Engineering Publishing Company. In the figure, the optical disc medium is driven directly by a cylindrical motor, and the optical pickup (head) is linearly moved in the inner and outer radial directions by a coarse motor (head drive actuator).

[0004]

Among the above conventional examples, the drive system shown in FIG. 1.2 "Basic configuration of optical disk memory" described on page 6 of "Optical disk technology" issued by Radio Technology Co., Ltd. A spindle motor for driving the medium and a coarse motor for moving the optical pickup in the radial direction of the disk are separately manufactured and arranged. For this reason, the space due to the clearance between the spindle motor and the head drive actuator, the point where the accuracy of the arrangement of the spindle motor and the head drive actuator is deteriorated, and the accuracy is obtained when the head drive actuator is composed of a plurality of components. In addition, there are problems such as difficulty in increasing the weight, increase in weight, and regression to thinning.

[0005] The present invention, except for the disadvantages of the prior art described above,
Provides compact, lightweight, thin, and highly reliable disk drives
Is what you do.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an adduction type spindle motor for driving a disk for performing at least one of recording, reproducing and erasing of information, and recording, reproducing and erasing of information on the disk. A head drive actuator for moving a head for performing at least one of the above in the radial direction of the disk, wherein the coil is wound around
Multiple spindles that generate drive torque with the rotor
Motor stator iron teeth, coil wound
Drive torque between the head drive actuator and the slider
Stator iron for multiple head drive actuators
Heart teeth, and between the rotor and the mover
And a driving ton between the rotor and the mover.
The stator core that does not generate
This can be achieved by having an integral stator formed in the body .

[0007]

[0008]

[0009]

[0010]

According to the above construction, the drive torque generating section for the adduction type spindle motor and the head drive actuator is provided.
Rotation of stator core teeth and adduction type spindle motor
Between the actuator and the actuator of the head drive actuator.
One a stator core is the driving torque nonoccurrence of the common
Parts can be shared by forming them on the body stator, eliminating the need for a device to attach the adduction spindle motor and head drive actuator, and improving assembly accuracy, resulting in smaller, lighter, thinner, and more reliable devices. Can be achieved , and the drive tor located between the rotor and the mover
The stator core, which is the non-lux-generating part, transfers the rotor magnetic flux to the outside.
No leakage and no leakage of the magnetic flux of the mover
So the adduction spindle motor and head drive actuator
Magnetic interference with the data can be prevented.

[0011]

[0012]

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment when the present invention is applied to an optical disk device. FIG. 2 shows an embodiment of a motor structure diagram in which a stator core of a disk drive spindle motor and a head drive actuator according to the present invention are integrated, and FIG. 3 shows a sectional structure thereof.

In FIG. 1, reference numeral 1 denotes an optical disk for performing at least one of recording, reproducing, and erasing of information. 2
Is a spindle motor for driving the optical disk.
An example using a permanent magnet brushless motor will be described. In addition, the types of spindle motors to which the present invention is applied include a DC machine, a reluctance motor, and a step motor. Here, the spindle motor 2 is shown in FIGS.
The rotor 3 is composed of a rotor 3 and a stator 4, and the rotor 3 constitutes a permanent magnet 5 and a magnetic circuit on the rotor 3 side in which N poles and S poles are arranged in a circumferential direction at substantially equal pitches. And a rotating yoke 6.

On the other hand, the stator 4 comprises a case 8, a stator core 9, which is a magnetic material, and a coil 10, and rotatably supports the rotor 3 via a bearing 7. Here, the spindle motor has a configuration having a torque generating portion (lower half) and a non-torque generating portion (upper half) around the rotor 3 as shown in the figure. The prior application has been filed for the shape and operation of this single spindle motor. Here, in the case of FIG. 2, the stator core 9C is moved from the center of the stator core 9 to the stator core 9C.
In the example of the figure, the distance from the inner diameter to the outer diameter (Z in the drawing) differs with respect to the angle. In general, besides this, a configuration may be adopted in which the head side has an arc shape, a curved shape, or the like, or the above-described head side shape is provided at two or more locations in the inner diameter of the stator core 9C. In FIG. 2, the permanent magnet 5 of the rotor 3 has an N pole,
The configuration is shown in which eight magnetic poles in which the S poles are arranged at a substantially equal pitch in the circumferential direction are arranged in the circumferential direction. The stator core 9 includes a magnetic pole 9A having a coil 10 and a magnetic pole 9B having no coil 10.
And a stator core yoke 9C. The magnetic pole 9A having the coil 10 positively generates a driving torque by an electromagnetic force between the current flowing through the coil 10 and the permanent magnet 5 of the rotor 3. It constitutes a so-called torque generating section. On the other hand, the magnetic pole 9B having no coil 10 does not generate a positive torque with the rotor 3 and forms a so-called torque non-generating portion. The role of the magnetic pole 9B constituting the non-torque generating part is as follows.
The magnetic flux generated by the permanent magnet 5 and the coil 10 of the rotor 3 is not leaked to the outside (this is particularly important for a magnetic disk drive spindle motor), and the permanent magnet 5 of the rotor 3 and the stator core 9 In cogging torque between the two.

FIG. 2 shows an example of a three-phase brushless motor (a magnetic pole position detecting element and the like are omitted here). For this reason, the magnetic pole 9A having the coil 10 of the driving section of the torque generating section has three poles. In this case, torque is generated between the permanent magnet 5 and the four poles of the permanent magnet 5 of the rotor 3 facing each other. The selection of 3: 4 for the number of magnetic poles and the number of permanent magnetic poles in a three-phase motor is used to reduce cogging torque. In addition, a magnetic pole number and a permanent magnet magnetic pole number of 3: 2 or the like are used. As an example of this case, the stator 4 is exactly the same as in FIG. 2, and only the permanent magnet 5 has a four-pole structure. The motor case 8 has a semicircular shape on the spindle motor 2 side according to the shape of the stator core 9 as shown in FIG. In FIG. 3, an optical disk is mounted on the upper part of the rotor 3 (the mounting structure is omitted), and the spindle motor 2 has a direct drive configuration in which the optical disk is directly driven.

On the other hand, the structure of the head drive actuator 12 for driving the head 11 will be described. As the head drive actuator, a reluctance and permanent magnet brushless rotary motor, a piezoelectric linear actuator, etc. can be considered similarly to the spindle motor. Here, the head drive actuator is an example of a permanent magnet brushless linear motor as shown in FIG. Show. The head drive actuator 12 includes a moving element 19 and a stator 18. The moving element 19 includes a permanent magnet 22 having N poles and S poles arranged at substantially equal pitches, and a moving element forming a magnetic circuit on the moving element 19 side. And a yoke 21. Here, the moving element 19 of the head feed actuator 12 is configured to be movable in the radial direction with respect to the spindle motor 2.

On the other hand, the stator 18 comprises a case 8 common to the spindle motor 2, a stator core 23, which is a magnetic material, and a coil 24. The stator core 23 is also the spindle motor 2
The magnetic pole 23A having the coil 24, the magnetic pole 23B having no coil 24, and the stator core yoke 23 as shown in FIG. The drive force is positively generated by the electromagnetic force between the drive force and the drive force. It constitutes a so-called torque generating section. On the other hand, the magnetic pole 23 having no coil 24
B does not generate a positive torque with the mover 19,
This constitutes a so-called torque non-generating section. The role of the magnetic pole 9B constituting the torque non-generating portion is to prevent the magnetic flux generated by the permanent magnet 22 and the coil 24 of the mover 19 from leaking to the outside, and to cogging torque between the permanent magnet 22 of the mover 19 and the stator core 23. Is to reduce.

FIG. 2 shows an example of a three-phase brushless motor (a magnetic pole position detecting element and a bearing mechanism are omitted) as in the case of the spindle motor 2, but has a coil 24 of a driving part of a torque generating part. The three magnetic poles 23A generate torque between the three magnetic poles 23A and the opposing four poles of the permanent magnet 5 of the rotor 3.

As described above, the spindle motor 2 and the head drive actuator 12 are integrated with the stator cores 9 and 23.
To improve the assembly accuracy of each part (for example, the spindle motor 2 and the head feed actuator 12
Accuracy and accuracy) and small size, light weight, and thinness associated with integration. In addition, at least one of the head 11 and the head drive actuator 12 is disposed on the same surface as the spindle motor 2 with respect to the disk 1, and the head is moved in the direction of an angle where the inner diameter of the stator core 9C of the spindle motor 2 is small. By arranging at least one of the head 11 and the head drive actuator 12, the distance in which the head 11 moves in the radial direction can be increased. In addition, thereby, the effective area of the disk 1 can be increased, the recording density (information amount / disk surface area) can be increased, and the size, weight, and thickness of the disk device can be reduced.

Therefore, the key point of the shape of the spindle motor 2 is how to reduce the distance from the center of the motor to the minimum outer diameter (Y in the figure) of the stator core yoke. In the case of FIG. 2, the point is how the radial length, that is, the thickness, of the bridge portion at the center of the stator magnetic pole 9B without the coil 10 can be reduced. However, if the thickness of the bridge is too small, magnetic saturation may occur and cogging torque may be generated. Therefore, it is desirable that the magnetic flux flowing therethrough is not saturated (magnetic interference between the spindle motor and the head drive actuator does not occur) and the minimum value is provided. In order to satisfy this condition and reduce the bridge thickness, the spindle motor must first have a multi-pole structure, and preferably has eight or more poles. The upper limit of the thickness of the bridge is preferably 2 mm or less.

In other words, the above-mentioned effect can be further enhanced by increasing the ratio between the length of the motor center of the spindle motor 2 and the portion having a large inner diameter of the stator core and the portion having a small inner diameter. it can. In the example of FIG. 2, the motor center of the spindle motor 2 and the stator core 9C
The ratio of the length of the portion having a larger inner diameter to the portion having a smaller inner diameter is shown as 1/3 or less.

As a configuration of the spindle motor 2 that can achieve the above-mentioned effects more effectively, the permanent magnet rotor 3 is configured such that the head drive actuator 12
This can be achieved by making a configuration in contact with the moving element 19. However, to achieve this, it is necessary to reduce the influence of the magnetic flux of the permanent magnet 5 on the outside. As an example of this, for example, it is conceivable to make the moving member constituting member of the head drive actuator 12 from a non-magnetic material. In this case, the structure of the spindle motor 2 is the same as the structure of FIG. 2 except that the magnetic pole 9B having no coil 10 is removed.
The configuration of the spindle motor 2 can be made simpler and smaller.

In FIG. 2, the head driving accuracy is improved by providing a driving torque generating portion on both sides of the moving element 19 in the head driving actuator 12, but when the accuracy is not so required, the driving is performed. The torque generating section may be arranged on only one side of the moving element 19.

Next, the operation of the optical disk device will be described with reference to FIG. 1. Reference numeral 13 denotes a control device for the spindle motor, 14 denotes a control device for the head drive actuator 12, and 15 denotes a control device for the head 11. Reference numeral 16 denotes a signal processing device. The spindle motor control device 13 supplies the spindle motor 2 with a motor current for rotating the spindle motor 2 at a constant speed based on a speed signal obtained from a speed sensor (not shown) provided in the spindle motor. On the other hand, the head drive actuator 12
The controller 14 controls the position of the head drive actuator 12 based on a position command and a position signal from a position sensor (not shown) of the head drive actuator 12. The control device 15 of the optical head 11 controls the trajectory based on trajectory information obtained from the optical head 11 via the signal processing circuit 16. The signal processing device 16 sends a signal for controlling the optical head 11 to an optimal position by the control device 15 of the optical head 11 based on information from the optical head 11.
1 to the control device 15 and the drive control device 1
7 is signaled.

The drive control unit 17 operates the control unit 13 of the spindle motor 2, the control unit 14 of the head drive actuator 12, and the control unit 15 of the head 11 according to an external signal, so as to grasp each operation unit and to transmit and receive signals. I do. Thus, system control of the optical disk device is performed.

The operation of the optical disk apparatus has been described above. The features of the brushless motor according to the present invention include a disk for performing at least one of recording, reproducing, and erasing of information, and a spindle motor 2 for driving the disk.
A head 11 for performing at least one of recording, reproduction, and erasing of information on the disk 1 and a head drive actuator 12 for enabling the head 11 to move in the radial direction of the disk 1; In a disk device having at least one of the head drive actuators 12 disposed on the same surface as the spindle motor 2 with respect to the disk 1, a magnetic material forming a drive torque generating unit for the spindle motor 2 and the head drive actuator 12; At least one of the coils is formed in an integrated structure, which makes it possible to realize a disk drive device and a disk drive suitable for realizing a small, lightweight, thin and highly reliable disk device. A plurality of drive motor devices suitable for realizing a drive device can be provided.

Next, FIG. 4 shows another embodiment of the present invention.

Here, the spindle motor 2 and the head drive actuator 12 are both constituted by rotary permanent magnet brushless motors, and the stator cores 9 and 23 forming the magnetic circuit of the spindle motor 2 and the head drive actuator 12 are used. An example of common production is shown. In FIG. 4, the same symbols as those in the embodiment of the present invention shown in FIGS. In the spindle motor 2, the permanent magnet rotor 3, the stator core 9A and the coil 10 are shown in FIG.
The configuration is exactly the same as that of the embodiment of the present invention shown in FIG.

On the other hand, the head drive head actuator 1
Reference numeral 2 denotes substantially the same configuration as the spindle motor 2, and in particular, the mover 19, the stator core 23A, and the coil 24 are shown by the same configuration as the spindle motor 2. Here, the configuration of the spindle motor 2 and the head drive actuator 12 is not limited to that shown in FIG. 4, but may be any as long as a plurality of motors are configured using the same stator core.

In the figure, the moving element 19 of the head driving actuator 12 is directly connected to the head 11 via the connector 25, and has a function of moving the head 11 as shown. Therefore, the head drive actuator 12 operates as a permanent magnet brushless motor that moves by a finite angle. In addition, the head 11 side of the head drive actuator 12 is formed of a stator core 23B that does not generate torque, and its outer shape can be made small, so that a space for moving the head 11 is provided, and it is small, lightweight, thin, and highly reliable. And a plurality of drive motor devices suitable for realizing the disk drive.

On the other hand, in this example, considering that the head drive actuator 22 only needs to operate as a permanent magnet brushless motor having a finite angle operation, for example, the pair of N and S permanent magnets 22 on the head 11 side of the moving element 22 are unnecessary. Accordingly, the stator core 23B on the head 11 side is not required. For example, a configuration in which the movable element yoke 21 and the head 11 are directly connected by the connector 25 or the like is conceivable, and a smaller and lighter configuration can be achieved.

In the above embodiment, the example in which the head 11 is directly driven has been described, but it is also possible to use a power transmission mechanism such as a gear.

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

According to the present invention, an adduction type spindle motor is provided.
Core teeth of the actuator and the head drive actuator
And the rotor and head drive actuator of the adduction type spindle motor.
With the stator core placed between the tutor mover and
By forming a common integrated stator, sharing of components, to improve the integration and assembly accuracy, the disk drive
The device can be made compact, lightweight, thin, and highly reliable .
The stator core placed between the rotor and the rotor is the rotor
To prevent the magnetic flux of the mover from leaking out
So that it does not leak to the
There is an effect that magnetic interference with the drive actuator can be prevented .

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an optical disk device according to an embodiment of the present invention.

FIG. 2 is a top view of the optical disk drive according to the embodiment of the present invention.

FIG. 3 is a sectional view taken along line AA ′ of FIG. 2;

FIG. 4 is a top view of a disk drive device according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Disc, 2 ... Spindle motor, 3 ... Rotator, 4
... stator, 9 ... stator core, 10 ... coil, 11 ... head, 12 ... head drive actuator, 23 ... stator core, 24 ... coil.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Kanazawa 4026 Kuji-cho, Hitachi City, Ibaraki Prefecture Hitachi, Ltd.Hitachi Research Laboratory (72) Inventor Tadashi Takahashi 4026 Kuji-machi, Hitachi City, Ibaraki Prefecture Hitachi, Ltd. Hitachi, Ltd. In the laboratory (72) Inventor Nobuyoshi Mutoh 4026 Kuji-cho, Hitachi City, Ibaraki Prefecture Hitachi, Ltd.Hitachi Research Laboratory Co., Ltd. (72) Inventor Shigeki Morinaga 4026 Kuji-machi, Hitachi City, Ibaraki Prefecture Hitachi, Ltd. Person Kazuo Onishi 7 Minamishiro-cho, Kanda, Chiyoda-ku, Tokyo Within Nihon Servo Co., Ltd. (56) References JP-A-58-159201 (JP, A) Full-fledged Sho 61-58840 (JP, U) 50-86107 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H02K 16/00 G11B 19/20 G11B 25/04 101

Claims (1)

(57) [Claims] 1. An add-on spindle motor for driving a disk for performing at least one of recording, reproducing, and erasing of information, and a head for performing at least one of recording, reproducing, and erasing of information on the disk. And a head drive actuator for moving the disk in the radial direction of the disk, wherein a coil is wound to rotate the inner rotation type spindle motor.
Multiple spindle motors that generate drive torque between
Stator core teeth and coils wound around the
Drive torque is generated between the
Stator core for multiple head drive actuators
And between the rotor and the mover
Drive torque between the rotor and the mover
Stator core that does not generate
A disk drive comprising an integral stator formed .