JPH065980B2 - Disk drive mechanism - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a drive device for a high-speed rotating recording medium disk used in a computer or the like, for example, a disk drive mechanism of a fixed (hard) disk drive device.

[Prior Art] A high-speed rotating recording medium disk drive used as a storage device of a computer, such as a fixed (hard) disk drive, has a large storage capacity, good accessibility, and high speed. Due to reasons such as performance, manufacturing technology is required to be highly sophisticated and, in recent years, it has been mass-produced.

This type of disk drive device is basically a disk drive mechanism for rotating a disk, a recording medium disk (fixed magnetic disk, etc.), and a head (magnetic head, etc.) for reading or writing information recorded on the disk. And a container for containing these.

As a disk drive mechanism of a fixed (hard) disk drive device used in a computer of a conventional example, an outer box, a recording medium fixed disk housed in the outer box and rotating at high speed, and the fixed disk are integrally rotated. A hub to be retained, an internal stator composed of a stator core and a stator coil, a rotary shaft arranged so as to be rotatable relative to the stator, and a cylinder supported by the rotary shaft and attached to the stator. Some include a brushless DC motor having an external rotor having magnetic poles made of permanent magnets separated by a gap, and a circuit element for controlling the rotation of the rotor.

The good accessibility described above as an advantage of the disk drive means that information continuously recorded on many tracks of a magnetic disk can be quickly read by a magnetic head. This speed is the rotational speed of the disk. And the speed of movement of the magnetic head in the radial direction. The rotation speed of this extremely high-speed disk, which is unusual for a driven body driven by a small motor of this kind, is controlled according to a clock unique to the computer. One of the basic performances required of the disk drive mechanism is to achieve uniform high-speed continuous rotation without wobbling (surface wobbling) of the disk surface.
That is, this is caused by the characteristic of extremely high speed rotation (for example, 3600 rpm), but in a fixed disk, the read / write head and the disk are not in contact with each other. That is, during the rotation of the disk, an extremely thin laminar air flow (1 μm
The head flies above the flying height (m or less) to continuously read and write recordable information on the surface of the disk. Therefore, if there is surface runout due to high-speed rotation of the disk surface, the head will hit and wear between the two members, so it is necessary to ensure a high degree of flatness during disk rotation so that there is no surface runout.

In addition, because of this extremely short flying distance due to the extremely thin air layer, very small particles enter the disk chamber, and if they are present between the head and the disk, the read / write operation will be performed.
This may cause a write error and even lead to disk failure. Therefore, in a fixed disk drive, it is necessary to keep the environment inside the disk chamber extremely clean. This cleanliness is the second important performance required of the disk drive mechanism.

[Problems to be Solved by the Invention] In recent years, such fixed disk drive devices have come to be used in extremely large quantities as computers have been developed.
For this reason, there is a demand for an inexpensive disk drive mechanism that can be mass-produced, but it is necessary to achieve this without impairing all of the high mounting accuracy, high-speed uniform rotation, and cleanliness of the disk chamber as described above. There is. Therefore, it is a first object of the present invention to provide an improved disk drive mechanism having a simple structure and a small number of parts used in this kind of disk drive device without impairing the required performance. .

A second object of the present invention is to provide a high-speed rotating recording medium disk drive mechanism capable of mass production with a compact arrangement of circuit elements mainly belonging to a brushless DC motor and a simplified wiring. .

[Means for Solving the Problems] An object of the present invention is to provide a disk drive mechanism incorporated in a disk drive device for a recording medium disk rotating at high speed, an outer box, and a recording medium fixed disk housed in the outer box and rotating at high speed. And a brushless DC motor for driving the disk, wherein the brushless DC motor comprises an inner stator including a stator core and a stator coil, and a relative rotation with respect to the stator. An outer rotor having magnetic poles made of permanent magnets, which are supported by the rotary shaft and are supported by the rotary shaft and separated from each other by a cylindrical gap in the stator; Is divided into two spaces, an upper part for accommodating the brushless DC motor and a lower part for accommodating the brushless DC motor, and a horizontal partition wall having an opening therein is provided. The moving mechanism includes a hub that holds the recording medium disc and is fixed to the rotating shaft, a circuit element that controls the rotation of the rotor, and a horizontal partition that closes the opening to seal the upper space. A flange member that is fixed and that penetrates the rotation shaft and that holds the stator in the vicinity of the opening in the lower space, wherein the rotation shaft is orthogonal to the flange in the center portion of the stator. Is rotatably held relatively and is axially defined, and the rotor has a cylindrical cup shape and is formed as an outer housing that surrounds and supports the magnetic pole, and has an open upper end. And a bottom portion whose center is fixed to the lower end portion of the rotary shaft.

How to achieve the above-mentioned demands of the disk drive mechanism is a problem, and the present application devises this configuration as follows.

Due to the requirement for uniform rotation, the disk drive mechanism usually has a vertical arrangement with respect to the positional relationship between the hub that holds the disk and the electric motor that drives it. In order to maintain the required cleanliness, in this application, the hub and the motor are separated by a completely sealed horizontal partition wall. It is desirable that the horizontal partition can naturally serve as a structure that supports the disk mechanism because of its arrangement. That is, if the drive mechanism can be easily attached to the horizontal partition, not only is the space extremely saved, but it is also advantageous in terms of its attachment accuracy. Further, since it is sufficient that only the completely-sealable horizontal partition wall can withstand these weights and vibrations, the cost of the container itself can be reduced.

Further, since it can be supported between the driving body and the driven body, it is advantageous not only in terms of mounting accuracy but also in terms of balance during rotation.

In the present application, the rotor is an outer rotor, and the outer rotor is in the shape of a cylindrical cup in order to support the horizontal partition wall, maintain sufficient mounting accuracy, and have a simple structure. It was decided to adopt a configuration in which a cylindrical cylinder is opened at the top. Further, it is possible to provide an extremely simple and compact disk drive mechanism that can be mass-produced in combination with other configurations.

[Operation] With this configuration in which the rotor of the brushless DC motor is used as the external rotor, it becomes easy to support the stator coil, and the inertia of the rotor itself increases, which is advantageous for uniform rotation.
The outer rotor of the motor was formed into a cylindrical cup shape with the upper part opened and the bottom part closed, so that the fixed member could be attached to the horizontal partition wall on the upper part of the electric motor. Therefore, since it is possible to adopt a structure in which it is supported between the driving body and the driven body, the masses of both are balanced during rotation, which is particularly advantageous for uniform rotation. By fixing the stator to the flange member, the flange member can be used as a base of the electric motor, whereby the electric motor, and thus the entire disk drive mechanism, can be fixedly supported on the horizontal partition wall (with the electric motor disposed below it). It was done.
This structure, in which the rotary shaft is directly connected to the external rotor and the rotary shaft is supported inside the stator, eliminates the need for thrust bearings. For this reason, it is not necessary to arrange the casing further outside, and it is possible to save parts. In addition, in supporting the stator, the sleeve can be manufactured as a part of the flange member to fix the stator on its periphery,
Alternatively, the sleeve may be manufactured separately from the support flange and fitted and fixed to the support flange. The flange member can be manufactured integrally with the stator at the stator manufacturing place, and the fixed shaft is penetrated during final assembly of the motor. This facilitates final assembly as a high-speed rotating disk device.

[Embodiment] Next, an embodiment of the present invention will be described with reference to the accompanying drawings.

An improved brushless DC motor assembly used in a disk drive according to the present invention is designated by the reference numeral 10 and includes a brushless DC motor 11, a flange member and an annular member 20. This brushless DC electric motor 11 has a rotatable rotary shaft 12, a fixed coil (stator coil) and an electric motor core (stator core) of this kind of electric motor, and a hollow rotary housing surrounding a permanent magnet forming a rotor.
14 (external rotor), a circuit element for the coil, that is, a drive electronic circuit 16, and a speed control circuit connected to the drive electronic circuit 16 for controlling the rotational speed of the rotary shaft 12 and including a rotational position detecting means. Composed of 18. All the said elements of the electric motor 11 are themselves necessary for a conventional brushless DC motor.

An annular member 20 is used which is a fixed part of the electric motor 11 or a substrate connected to a central abutment 22 for supporting the circuit elements, i.e. the drive electronics 16 and the speed control circuit 18. As a result, these circuits form a compact unit containing the electric motor 11. The annular member 20 replaces an external additional circuit section, that is, a black box, which is separated from the inner motors of these two circuits. Such a black box has been conventionally used for this kind of ordinary electric motor.

As shown in FIG. 1, the various components 24 of the drive electronics 16 and speed control circuit 18 include an upper end 28 of the motor housing 14 and an annular mounting support flange 30 secured to the central abutment 22 of the motor 11. Is disposed in the chamber or space 26 between them. Lead 31 extends from circuits 16 and 18 and is connected to a DC power source at the appropriate location.

The assembly 10 has a fan 32 having a large number of blades 33 fixed to one end of a rotary shaft 12, the shaft end 34 of which is a housing.
It projects outward and downward from the bottom of 14. The fan 32 is at the bottom and causes air to flow in the direction of arrow 36 in FIG. 1 for cooling purposes. Instead of that, a large number of spacing blades 33a
Similarly (see FIG. 5) can be mounted on the outer cylindrical surface of the rotating housing 14. These vanes operate to cause air to flow along the path indicated by arrow 36a for cooling purposes.

FIG. 4 shows a process of assembling the electric motor 10. The rotary shaft 12 has a bottom 40 of the housing 14 having an opening 42.
The central sleeve 44, which is secured by the heap bushing 38 and thus surrounds the axis of rotation, projects upwards from the housing. The sleeve 44 forms part of the central abutment 22,
The sleeve is also pressed and fixed in a tubular part 46 integrated with the support flange 30. Of course, this sleeve can also be formed integrally with the flange. A pair of bearings 48 within the sleeve 44 rotatably supports the rotating shaft 12 within the sleeve rotatably with high accuracy orthogonal to the flanges, whereby the rotating shaft and housing 14 are mounted with the flanges in fixed positions within the adjacent structure. When rotated, it rotates relative to the sleeve and flange 30. A pair of spacing rings 50 hold the bearing in place. Further, the washer assembly 52 retained by the retaining ring 54 biases the axis of rotation upward relative to the sleeve 44. The upper and lower bearings should be spaced as far as possible to improve the accuracy of the disc rotation.

The housing 14 has several permanent magnets 56 fixed to its inner surface. These magnets surround an iron core 58 provided for several coils 60 and 62. The magnet 56, the iron core 58 and the coils 60, 62 are the usual elements of this type of brushless DC motor. The housing 14 and the magnet 56 form the rotor of the electric motor 11.

The annular support member 20 fixed to the tubular portion 46 of the flange 30 has an outer diameter substantially equal to the outer diameter of the housing 14 and the flange 30. Thus, the annular support member 20 is retained within the outer cover of the electric motor 11 to form a compact unit. The annular member 20 has a through center hole 64 (see FIG. 2). The central hole 64 fits into the sleeve 44, and the tubular portion 46
It has sufficient dimensions to be secured to the underside of the lower flat surface 66 (see FIG. 4). The annular member 20 is affixed to the surface 66 by any suitable method such as fasteners or gluing. The axial length of the tubular portion 46 is in the space 26 without interfering with the flange 30.
Take enough to accommodate 24.

The electric motor assembly 11 includes a fixed disk drive mechanism and a housing 72 having a base 72 and a removable cover 74, although it can be used for several different applications other than the disk drive mechanism of the present invention. It is specifically intended for a type of disk drive unit 68. cover
The space 76 within 74 and upper base 72 is formed to contain a pair of rotatable disks 78 and 80 secured to hub 82. The hub 82 is adjustably and detachably mounted on the upper end of the rotating shaft 12.

The base 72 has an upper horizontal bulkhead 86 and has a space 84 for receiving the electric motor assembly 10. Support flange for base 72
The 30 is releasably joined by screws or other fastening fasteners. In such an arrangement, the rotating shaft 12 is a horizontal partition.
Extending upward through an opening 90 in 86, so that the upper end of the rotating shaft projects into the upper space 76 to receive the hub 82 which is to be secured to the rotating shaft 12 for rotation in the upper space 76. To do. If a fan 32 is used in the assembly 10, it is coupled to the bottom of the cup-shaped housing, for example to the lower end of the rotary shaft 12, and is shiftable with respect to the disks 78 and 80. It acts to blow cooling air in the direction of arrow 36 into a region 102 containing a circuit board or other electronic circuit connected to the same (see FIG. 1).

In use, the motor assembly 10 is coupled to the base 72 via the support flange 30 fixed to the horizontal bulkhead 86. When power is supplied to the drive electronic circuit 16 and the speed control circuit 18,
The electric motor 11 is driven so that the rotating shaft 12 and the housing 14 rotate in the space 84 relative to the flange 30 and the abutment 22. As a result of the rotation of the motor housing 14, the disks 78 and 80, as well as the fixed member 20, are head 94.
It can be rotated relative to. The fan can be composed of blades formed directly on the outer periphery of the housing 14 as shown in FIG. Feather 33 or 33
The a rotates with the housing 14 and causes air to flow laterally for cooling purposes.

[Advantages of the Invention] The present invention provides a disk drive mechanism having a simple structure including a flange member having a sealing function, which is supported only by the horizontal partition wall also configured as a structure according to the configuration described in the first aspect of the invention. Can be provided.

That is, by adopting a flange member, it was decided to support the disk mechanism while maintaining hermeticity.

With this configuration, it is possible to support the brushless DC motor without the need to provide a special accessory, for example, a hanging device, and to make a strict requirement on the relative arrangement with the head (disk surface runout prevention) and to clean the disk chamber. It can also meet the demands of sex.

By configuring the rotor (external rotor) of the DC motor as the outermost housing, it is possible to increase GD ² and maintain the uniform rotation required for the drive mechanism, and the flange member is restricted by the dimensions of the rotor. Never. Due to mounting accuracy,
It is possible to support the horizontal partition walls while appropriately selecting conditions advantageous in strength. This makes it possible to meet the above-mentioned demands for strength and precision required for the disk drive mechanism.

The rotor, which is a cylindrical housing, has a cup shape with an open top, and the entire drive mechanism can be supported by the support flange between the motor and the hub. Rotational force is transmitted through the rotation shaft that is supported by the bearing through the support flange, so that the balance of the mass does not occur and the shaft does not run out during high speed rotation, and the rotation balance can be maintained. The precision of the flatness of rotation is also high. The flange serves as an isolation between the motor and the disk, so that the aforementioned cleanliness of the disk chamber is maintained and the number of parts is reduced. Furthermore, since the lower part of the rotating shaft is fixed to the rotor and the axial position is regulated within the stator, a separate housing is not required externally, and the thrust bearing that was conventionally required when the disk drive mechanism was placed vertically I no longer need it.

Since the rotor is the outermost part, it is possible to use it for cooling by forming a blade for blowing air on the rotor if necessary, and it is possible to reduce the number of parts.

With the configuration of the present invention as described above, it is possible to manufacture a disk drive mechanism that rotates at high speed with a minimum number of parts and a minimum arrangement space.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of an improved disk drive mechanism according to the present invention, which is shown mounted on a container of a disk drive unit. FIG. 2 is a top plan view of an annular member that includes drive electronics and speed control circuitry and serves as a platform for the disk drive, primarily the circuit elements of a brushless DC motor. The scale is smaller than that in FIG. FIG. 3 is a top plan view of a brushless DC motor included in the disk drive mechanism according to the present invention, with parts removed to show the details of the structure. FIG. 4 is a cross-sectional view of the brushless DC motor of the disk drive mechanism according to the present invention. FIG. 5 is a part of FIG. 1 and shows a case where a large number of blower blades are provided on the outer surface of the motor housing. The correspondence of the main reference numerals in the figure is as follows. 10: Brushless DC motor assembly (including flange member) 11: Brushless DC motor 12: Rotating shaft 14: Motor housing (rotor) 16: Drive electronic circuit 18: Speed control circuit 20: Annular member 22: Central abutment 30 : Support flange 32: Fans 33, 33a: Blades 82: Hub 86: Horizontal bulkhead

 ─────────────────────────────────────────────────── ───Continued from the front page (72) Inventor Alfretdo Hasra-Mountain in Vienne Revin Avenir 450, Calif.・ View drive 5 (56) References Open 52-105013 (JP, U) Open 52-42209 (JP, U) Open 53-156005 (JP, U)

Claims (4)

[Claims] 1. A high-speed disk drive mechanism comprising an outer box, a recording medium fixed disk housed in the outer box and rotating at a high speed, and a brushless DC electric motor for driving the disk, wherein the brushless DC electric motor is provided. Is an internal stator composed of a stator core and a stator coil, a rotary shaft arranged so as to be rotatable relative to the stator, a permanent shaft supported by the rotary shaft and separated by a cylindrical space in the stator. And an outer rotor having a magnetic pole made of a magnet, wherein the outer box divides the inside into two spaces, an upper part for housing the disk and a lower part for housing the brushless DC motor, and an opening therein. The drive mechanism further comprises a horizontal partition having a hub, which holds the recording medium disk and is fixed to the rotation shaft, and a circuit element which controls rotation of the rotor. And a flange member that is fixed to the horizontal partition wall so as to close the opening and seals the upper space, allows the rotary shaft to penetrate, and holds the stator in the vicinity of the opening in the lower space. The rotary shaft is rotatably held relative to the flange in the central portion of the stator so as to be rotatable relative to the flange, and the position thereof is defined in the axial direction; and the rotor has a cylindrical cup shape. A disk drive mechanism comprising: an outer housing that surrounds and supports the magnetic pole, and has an open upper end and a bottom whose center is fixed to the lower end of the rotating shaft. 2. The disk drive mechanism according to claim 1, wherein the circuit element is arranged on a support fixed between the flange member and the stator. . 3. The flange member is composed of a flange portion and a sleeve portion, and the pivotal support of the rotary shaft is carried out in the sleeve portion.
The disk drive mechanism according to item 2 or item 3. 4. The disk drive mechanism according to claim 1, wherein the outer rotor is provided with a blower blade on its outer surface.