JPH06223493A - Disk driving device - Google Patents

Abstract

PURPOSE:To make a stator coil thinner while reducing manufacturing cost by winding a wire on a core in a state in which stator tooth part cores are separated every one piece when the stator coil constituting a disk driving device is manufactured and mounting the tooth part cores to inner peripheral cores of the stator. CONSTITUTION:A stator coil 6 is formed by winding a wire on stator tooth part cores 15 being in a state before stator inner peripheral cores 16 are mounted. At the time, since the cores 15 are made a state in which they are separated every one piece, through the number of wires is increased, winding operation is easy. Well-ordered winding of a wire is made easy and it enables increasing the number of windings, and generated torque is increased. After that, the cores 15 forming the coil 6 is inserted into a convex part 16a of the stator inner peripheral cores 16 and fixed by adhesion. Thus, it is made possible that a width of winding is made 5 times or more as thick as the stator core, and thickness is made half or less than conventional thickness holding cross section of the core 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive device which can be made thin without reducing generated torque.

[0002]

2. Description of the Related Art A disk drive device for driving a disk-shaped recording medium such as a flexible disk is capable of further thinning, downsizing, and power consumption reduction in response to thinning, downsizing and handyness of a personal computer. It has been demanded.
Generally, this disk drive uses a brushless DC motor that is small in size, has a large torque, facilitates speed control and positioning control, does not require brush replacement, and has a long life.

FIG. 3 is a side sectional view showing a conventional disk drive device disclosed in, for example, Japanese Utility Model Laid-Open No. 3-98754. In the figure, 1 is a spindle that fits into a central hole of a flexible disk (not shown) and is integrated with it.
Reference numeral 2 is a chucking portion that is attached to the spindle 1 to fix the flexible disk, 3 is a disk-shaped rotor that is attached to the spindle 1 and rotates the spindle 4, and 4 is a rotor 3
Is a permanent magnet attached to the lower surface of the. Here, as the permanent magnet 4, a ferrite-based or rare-earth-based plastic magnet is adopted. Reference numeral 5 is a printed circuit board arranged below the permanent magnet 4, 6 is a stator coil attached to the lower surface of the printed circuit board 5, 7 is a chassis to which the printed circuit board 5 is attached, and 8 and 9 are spindles 1 attached to the chassis 7. The ball bearings and the oilless bearings 10 that rotatably support the are attached to the chassis 7 and are made of an iron plate, and thus are a high-permeability back yoke. Printed circuit board 5 and back yoke 1
0 is attached to the chassis 7 with screws 11.

Next, the operation of the conventional disk drive device will be described. The spindle 1, the rotor 3 and the permanent magnet 4 are integral and rotatable.
The position of the magnetic pole is detected by a magnetic pole position detection device (not shown) mounted on the printed circuit board 5. Depending on the position of this magnetic pole, the most suitable stator coil 6 is selected by means not shown and current is supplied. The permanent magnet 4 is rotated by receiving a force from the rotating magnetic field generated as a result, the spindle 1 is also rotated, and the flexible disk attached to the spindle 1 is rotated. Then, a head (not shown) is slid on the flexible disk to record and reproduce data.

In the above disk drive device, since the permanent magnet 4 and the stator coil 6 are arranged in the thickness direction (rotational axis direction of the spindle 1), attractive force acts between the permanent magnet 4 and the back yoke 10. The bending load on the rotor 3 and the spindle 1 increases. For this reason, it is necessary to widen the space between the permanent magnet 4 and the back yoke 10, thicken the rotor 3, and increase the rigidity of the spindle 1, and it is possible to meet the demand for thinner and smaller disk drive devices. Can not.

As an improvement measure for the problem, it has been proposed to change the arrangement of the permanent magnet 4 and the stator coil 6. Figure 4
5 and 6 are a side sectional view and a plan sectional view showing a conventional disk drive device as an improvement measure. In the drawing, 12 is a stator core around which a stator coil 6 is wound. The stator core 12 is integrally manufactured from a silicon steel plate or an iron-cobalt alloy plate, and its outer peripheral portion faces the inner peripheral portion of the ring-shaped permanent magnet 4 with a constant magnetic gap. 13 is a base body to which the stator core 12, the ball bearing 8 and the oilless bearing 9 are attached, 14
Is a screw for attaching the stator core 12 and the printed circuit board 5 to the base 13.

According to the disk drive device having such a configuration, since the bending load on the rotor 3 and the spindle 1 is small and it is not necessary to increase the rigidity thereof, the disk drive device can be made thin, compact and low in power consumption. Is advantageous to meet the requirements of In order to reduce the thickness of the disk drive device having such a configuration, it is effective to make the stator core 12 thin.

In general, the torque generated by the disk drive is determined by the current flowing through the stator coil 6 and the stator coil 6
And the product of the effective magnetic flux passing through the stator coil 6. If the stator core 12 is made thinner without changing other conditions, the effective magnetic flux becomes smaller. Therefore, in order to keep the torque small in this case, the current or the number of turns must be increased. However, increasing the current is against the demand for low power consumption, and increasing the number of turns without changing the thickness of the winding is against the demand for thinness and miniaturization. To increase the number of turns while satisfying the requirements for thinness and miniaturization, thin windings may be used, but the electrical resistance of the windings increases, which violates the demand for low power consumption. From the above, in order to prevent the torque from being reduced when the stator core 12 is made thin, it is necessary to devise so that the effective magnetic flux is not reduced.

The effective magnetic flux is determined by the saturation magnetic flux density of the material of the stator core 12, the cross-sectional area of the stator core 12, the saturation magnetic flux density of the permanent magnet 4, and the coercive force. Regarding the material of the stator core 12 and the permanent magnet 4, it is not a structural problem, so if it is not considered here, it is concluded that the sectional area of the stator core 12 is not reduced in order to reduce the torque. Reach Therefore, it is necessary to increase the width W (see FIG. 5) of the portion of the stator core 12 around which the stator coil 6 is wound.

[0010]

As described above,
To reduce the torque of the conventional disk drive device without reducing the torque as an improvement measure, the stator core 1
It is necessary to increase the width W of 2. However, in the conventional disk drive device, as is clear from FIG.
When the width W is increased, the gap between the adjacent stator coils 6 becomes smaller, which makes it difficult to wind the stator coils 6 and thus raises the manufacturing cost.

The present invention has been made in order to solve the above problems, and it is possible to reduce the thickness while avoiding an increase in manufacturing cost due to the difficulty of winding the stator coil. The object is to obtain a disk drive device capable of performing.

[0012]

DISCLOSURE OF THE INVENTION A disk drive device according to the present invention comprises a spindle that rotates integrally with a disk-shaped recording medium, a rotor mounted on the spindle, and a ring-shaped permanent magnet mounted on the rotor. , A plurality of stator tooth cores arranged at a constant gap from the inner peripheral surface of the permanent magnet, stator coils wound around each of the stator tooth cores, and a stator to which the stator tooth cores are attached. An inner peripheral core, a base to which the stator inner peripheral core is attached, and a bearing attached to the base to rotatably support the spindle are provided.

[0013]

In the disk drive device of the present invention, a winding is wound around the stator tooth cores separated from each other to form a stator coil, and then the stator tooth cores are attached to the inner stator core.

[0014]

1 and 2 are a side sectional view and a plan sectional view, respectively, of a disk drive device according to an embodiment of the present invention, which is the same as or equivalent to the conventional disk drive device shown in FIGS. Are denoted by the same reference numerals, and description thereof will be omitted. A flexible disk and a head are also shown in FIG. In the figure, reference numeral 15 denotes an I-shaped stator tooth core in which one stator coil 6 is wound, and 16 is a stator to which the stator tooth core 15 after winding of the stator coil 6 is attached. Inner peripheral core, 17 is a ring disposed between the stator inner peripheral core 16 and the printed circuit board 5, 18
Is the soldering part of the winding of the stator coil 6, 19, 20
Is a flexible disk recording medium, jacket, 21
Is a head for contacting and sliding on the medium 19 to record and reproduce data.

Next, a method of assembling the disk drive device of the above embodiment will be described. First, the stator inner peripheral core 16
The stator coil 6 is formed by winding a winding around the stator tooth core 15 in a state before being attached to. At this time, since the stator tooth cores 15 are separated one by one, the winding work is not difficult even if the number of windings is increased. In addition, it is easy to align and wind the windings, that is, to perform the aligned winding, and according to the aligned winding, it is possible to increase the number of windings and increase the generated torque. Stator tooth core 15 with the stator coil 6 formed
Is inserted between the convex portions 16a of the inner peripheral core 16 of the stator and fixed by adhesion.

In the conventional case in which the stator core 12 has an integral structure, the width W is 2 to 3 times the thickness of the stator core 12 in order to prevent the stator core 12 from bending and making the winding work difficult. Although it was necessary to reduce the number of times to less than twice, in the case of this embodiment having the structure in which the stator tooth portion core 15 and the stator inner peripheral core 16 can be separated, the winding work of the winding is easy, The width W can be five times or more the thickness of the stator core 12. Therefore, the thickness of the stator tooth core 15 can be reduced to 1/2 or less of the conventional thickness while maintaining the cross-sectional area of the stator tooth core 15.

Although the recording medium driven by this disk drive device is a flexible disk, the same effect can be obtained with a hard disk or an optical disk.

[0018]

According to the disk drive device of the present invention,
A spindle that rotates integrally with a disk-shaped recording medium, a rotor that is attached to the spindle, a ring-shaped permanent magnet that is attached to the rotor, and an inner peripheral surface of the permanent magnet that are spaced apart by a certain gap. A plurality of stator tooth cores, a stator coil wound around each of the stator tooth cores, a stator inner peripheral core to which the stator tooth cores are attached, a base body to which the stator inner peripheral cores are attached, and a base body And a bearing for rotatably supporting the spindle, which is advantageous in that the manufacturing cost can be prevented from increasing due to difficulty in winding the stator coil, and the thickness can be reduced. .

[Brief description of drawings]

FIG. 1 is a side sectional view of a disk drive device showing an embodiment of the present invention.

FIG. 2 is a plan sectional view of a disk drive device showing an embodiment of the present invention.

FIG. 3 is a side sectional view showing an example of a conventional disk drive device.

FIG. 4 is a side sectional view showing another example of a conventional disk drive device.

5 is a plan sectional view of the conventional disk drive device shown in FIG.

[Explanation of Codes] 1 Spindle 3 Rotor 4 Permanent Magnet 6 Stator Coil 8 Ball Bearing (Bearing) 9 Oilless Bearing (Bearing) 13 Base 15 Stator Teeth Core 16 Stator Inner Core 19 Recording Medium

[Procedure amendment]

[Submission date] November 15, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction content]

[Document name] Statement

Title: Disk drive device

[Claims]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk drive device which can be made thin without reducing generated torque.

[0002]

2. Description of the Related Art A disk drive device for driving a disk-shaped recording medium such as a flexible disk is capable of further thinning, downsizing, and power consumption reduction in response to thinning, downsizing and handyness of a personal computer. It has been demanded.
Generally, this disk drive uses a brushless DC motor that is small in size, has a large torque, facilitates speed control and positioning control, does not require brush replacement, and has a long life.

FIG. 3 is a side sectional view showing a conventional disk drive device disclosed in, for example, Japanese Utility Model Laid-Open No. 3-98754. In the figure, 1 is a spindle that fits into a central hole of a flexible disk (not shown) and is integrated with it.
Reference numeral 2 is a chucking portion that is attached to the spindle 1 to fix the flexible disk, 3 is a disk-shaped rotor that is attached to the spindle 1 and rotates the spindle 4, and 4 is a rotor 3
Is a permanent magnet attached to the lower surface of the. Here, as the permanent magnet 4, a ferrite-based or rare-earth-based plastic magnet is adopted. Reference numeral 5 is a printed circuit board arranged below the permanent magnet 4, 6 is a stator coil attached to the lower surface of the printed circuit board 5, 7 is a chassis to which the printed circuit board 5 is attached, and 8 and 9 are spindles 1 attached to the chassis 7. The ball bearings and the oilless bearings 10 that rotatably support the are attached to the chassis 7 and are made of an iron plate, and thus are a high-permeability back yoke. Printed circuit board 5 and back yoke 1
0 is attached to the chassis 7 with screws 11.

Next, the operation of the conventional disk drive device will be described. The spindle 1, the rotor 3 and the permanent magnet 4 are integral and rotatable.
The position of the magnetic pole is detected by a magnetic pole position detection device (not shown) mounted on the printed circuit board 5. Depending on the position of this magnetic pole, the most suitable stator coil 6 is selected by means not shown and current is supplied. The permanent magnet 4 is rotated by receiving a force from the rotating magnetic field generated as a result, the spindle 1 is also rotated, and the flexible disk attached to the spindle 1 is rotated. Then, a head (not shown) is slid on the flexible disk to record and reproduce data.

In the above disk drive device, since the permanent magnet 4 and the stator coil 6 are arranged in the thickness direction (rotational axis direction of the spindle 1), attractive force acts between the permanent magnet 4 and the back yoke 10. The bending load on the rotor 3 and the spindle 1 increases. For this reason, it is necessary to widen the space between the permanent magnet 4 and the back yoke 10, thicken the rotor 3, and increase the rigidity of the spindle 1, and it is possible to meet the demand for thinner and smaller disk drive devices. Can not.

As an improvement measure for the problem, it has been proposed to change the arrangement of the permanent magnet 4 and the stator coil 6. Figure 4
5 and 6 are a side sectional view and a plan sectional view showing a conventional disk drive device as an improvement measure. In the drawing, 12 is a stator core around which a stator coil 6 is wound. The stator core 12 is integrally manufactured from a silicon steel plate or an iron-cobalt alloy plate, and its outer peripheral portion faces the inner peripheral portion of the ring-shaped permanent magnet 4 with a constant magnetic gap. 13 is a base body to which the stator core 12, the ball bearing 8 and the oilless bearing 9 are attached, 14
Is a screw for attaching the stator core 12 and the printed circuit board 5 to the base 13.

According to the disk drive device having such a configuration, since the bending load on the rotor 3 and the spindle 1 is small and it is not necessary to increase the rigidity thereof, the disk drive device can be made thin, compact and low in power consumption. Is advantageous to meet the requirements of In order to reduce the thickness of the disk drive device having such a configuration, it is effective to make the stator core 12 thin.

In general, the torque generated by the disk drive is determined by the current flowing through the stator coil 6 and the stator coil 6
And the product of the effective magnetic flux passing through the stator coil 6. If the stator core 12 is made thinner without changing other conditions, the effective magnetic flux becomes smaller. Therefore, in order to keep the torque small in this case, the current or the number of turns must be increased. However, increasing the current is against the demand for low power consumption, and increasing the number of turns without changing the thickness of the winding is against the demand for thinness and miniaturization. To increase the number of turns while satisfying the requirements for thinness and miniaturization, thin windings may be used, but the electrical resistance of the windings increases, which violates the demand for low power consumption. From the above, in order to prevent the torque from being reduced when the stator core 12 is made thin, it is necessary to devise so that the effective magnetic flux is not reduced.

The effective magnetic flux is determined by the saturation magnetic flux density of the material of the stator core 12, the cross-sectional area of the stator core 12, the saturation magnetic flux density of the permanent magnet 4, and the coercive force. Regarding the material of the stator core 12 and the permanent magnet 4, it is not a structural problem, so if it is not considered here, it is concluded that the cross-sectional area of the stator core 12 is not reduced in order to reduce the torque. Reach Therefore, it is necessary to increase the width W (see FIG. 5) of the portion of the stator core 12 around which the stator coil 6 is wound.

[0010]

As described above,
To reduce the torque of the conventional disk drive device without reducing the torque as an improvement measure, the stator core 1
It is necessary to increase the width W of 2. However, in the conventional disk drive device, as is clear from FIG.
When the width W is increased, the gap between the adjacent stator coils 6 becomes smaller, which makes it difficult to wind the stator coils 6 and thus raises the manufacturing cost.

The present invention has been made in order to solve the above problems, and it is possible to reduce the thickness while avoiding an increase in manufacturing cost due to the difficulty of winding the stator coil. The object is to obtain a disk drive device capable of performing.

[0012]

DISCLOSURE OF THE INVENTION A disk drive device according to the present invention comprises a spindle that rotates integrally with a disk-shaped recording medium, a rotor mounted on the spindle, and a ring-shaped permanent magnet mounted on the rotor. , A plurality of stator main cores that are arranged apart from the inner peripheral surface of the permanent magnet by a certain gap, stator coils wound around each of the stator main cores, and a stator inner peripheral core to which the stator main core is attached. And a base to which the stator inner peripheral core is attached, and a bearing attached to the base to rotatably support the spindle.

[0013]

In the disk drive device of the present invention, the winding is wound around the stator main core in the separated state to form the stator coil, and then the stator main core is attached to the stator inner peripheral core.

[0014]

1 and 2 are a side sectional view and a plan sectional view, respectively, of a disk drive device according to an embodiment of the present invention, which is the same as or equivalent to the conventional disk drive device shown in FIGS. Are denoted by the same reference numerals, and description thereof will be omitted. A flexible disk and a head are also shown in FIG. In the figure, 15 is an I-shaped stator main core in which one stator coil 6 is wound, and 16 is an inner circumference of a stator to which the stator main core 15 is attached after the winding of the stator coil 6 is completed. Core, 17 is stator inner peripheral core 16
And a printed circuit board 5, a reference numeral 18 is a soldering portion of a winding of the stator coil 6, a reference numeral 20 is a recording medium of a flexible disk, a jacket is a reference numeral 21, and a medium 19 is in contact with the recording medium to slide data. A head for recording and reproducing.

Next, a method of assembling the disk drive device of the above embodiment will be described. First, the stator inner peripheral core 16
The stator coil 6 is formed by winding a winding around the stator main core 15 before being attached to the stator main core 15. At this time, since the stator main cores 15 are separated one by one,
Even if the number of windings is increased, winding work is not difficult. In addition, it is easy to align and wind the windings, that is, to perform the aligned winding, and according to the aligned winding, it is possible to increase the number of windings and increase the generated torque. The stator main core 15 on which the stator coil 6 is formed is inserted between the convex portions 16a of the stator inner peripheral core 16 and fixed by adhesion.

In the conventional case in which the stator core 12 has an integral structure, the width W is 2 to 3 times the thickness of the stator core 12 in order to prevent the stator core 12 from bending and making the winding work difficult. Although it was necessary to set the width within twice, in the case of this embodiment having a structure in which the stator main core 15 and the stator inner peripheral core 16 can be separated, the winding work of the winding is easy, It is possible to make W 5 times or more the thickness of the stator core 12. Therefore, while maintaining the cross-sectional area of the stator main core 15, its thickness is
It can be 2 or less.

Although the recording medium driven by this disk drive device is a flexible disk, the same effect can be obtained with a hard disk or an optical disk.

[0018]

According to the disk drive device of the present invention,
A spindle that rotates integrally with a disk-shaped recording medium, a rotor that is attached to the spindle, a ring-shaped permanent magnet that is attached to the rotor, and an inner peripheral surface of the permanent magnet that are spaced apart by a certain gap. A plurality of stator main cores, a stator coil wound around each of the stator main cores, a stator inner peripheral core to which the stator main core is attached, a base body to which the stator inner peripheral core is attached, and a stator main body attached to the base body. Since the bearing for rotatably supporting the spindle is provided, there is an effect that the manufacturing cost can be prevented from increasing due to difficulty in winding the stator coil, and the thickness can be reduced.

[Brief description of drawings]

FIG. 1 is a side sectional view of a disk drive device showing an embodiment of the present invention.

FIG. 2 is a plan sectional view of a disk drive device showing an embodiment of the present invention.

FIG. 3 is a side sectional view showing an example of a conventional disk drive device.

FIG. 4 is a side sectional view showing another example of a conventional disk drive device.

5 is a plan sectional view of the conventional disk drive device shown in FIG.

[Explanation of Codes] 1 Spindle 3 Rotor 4 Permanent Magnet 6 Stator Coil 8 Ball Bearing (Bearing) 9 Oilless Bearing (Bearing) 13 Base 15 Stator Main Core 16 Stator Inner Core 19 Recording Medium

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadashi Hasegawa 2-25 Sakaemachi, Koriyama City Mitsubishi Electric Corporation Koriyama Factory

Claims (1)

[Claims] 1. A spindle that rotates integrally with a disc-shaped recording medium, a rotor attached to the spindle, a ring-shaped permanent magnet attached to the rotor, and an inner peripheral surface of the permanent magnet. A plurality of stator tooth cores arranged apart from each other by a constant gap; a stator coil wound around each of the stator tooth cores; a stator inner circumferential core to which the stator tooth cores are attached; An inner peripheral core is attached to the base body, and a bearing that is attached to the base body and rotatably supports the spindle. The stator tooth core is provided with the stator inner periphery after the stator coil is wound. A disk drive device attached to the core.