JP3358667B2 - Disk rotation motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk rotation motor incorporated in a disk file device.

At present, disks are mainly 3.5 inches in diameter, but in the future, disk diameters will be reduced to 2.5 inches, and even to 1.8 inches, and disk file devices will tend to be smaller and thinner. It is in.

As the size of the disk decreases, the center hole diameter of the disk also decreases (for a 1.8-inch disk,
The center hole diameter is 12 mm), and the disk rotation motor using a brushless motor is required to be downsized.

[0004]

2. Description of the Related Art FIGS. 14 and 15 show an example of a conventional disk rotation motor 1. FIG.

[0005] Reference numeral 2 denotes a hub, which is supported by bearings 4 and 5 with respect to the fixed shaft 3. A disk 6 is fixed to the hub 2. 7 is a disk rotation axis.

The disk rotating motor 1 is incorporated inside the hub 2 and between the bearings 4 and 5.

Reference numeral 8 denotes an armature core, and the fixed shaft 3
It is fixed to.

Reference numeral 9 denotes a winding, and a winding axis 10 is in a direction orthogonal to the fixed shaft axis 3. Reference numeral 11 denotes an annular permanent magnet, which is magnetized in a large number in the circumferential direction and is fixed to the inner periphery of the hub 2.

The head 8a of the armature core 8 and the annular permanent magnet 1
1 are radially opposed to each other.

[0010]

However, in the conventional motor 1, the head 8a of the armature core 8 constituting the stator is provided.
And the windings 9 are arranged in the radial direction of the motor 1, so that the annular head placement space 15 for arranging the head 8 a and the windings 9 on the radial direction of the motor 1 are arranged. And a base space 17 for arranging the base (stator yoke) 8b of the armature core 8 is required.

[0011] Therefore, the motor 1 will be the diameter D ₁ becomes large, it is difficult to correspond to the size of the disk, in fact, when the rotating motor of the small disk such as 1.8 inches, As shown in FIG. 14, the bearings 4 and 5 must be installed in the up-down direction, which increases the height dimension, and there is a problem that the thickness of the disk file device cannot be reduced.

Incidentally, when the size of the disk is reduced, the disk rotation motor 1A may be arranged on the lower surface side of the chassis base of the disk file device as shown by a two-dot chain line in FIG. However, also in this case, the height of the disk file device is increased, and the thickness of the disk file device cannot be reduced.

FIG. 16 shows an axial gap type flat motor 70 which is another example of the related art. 71 is a stator yoke, 72 is a stator coil, 73 is a rotor yoke, 7
4 is a rotor magnet.

In the motor 70, a sufficient distance cannot be taken in the radial direction involved in the torque generation of the coil in a limited allowable space, so that sufficient efficiency cannot be obtained. In addition, since it is a so-called slotless type using an air-core coil, the air-gap magnetic flux density is hard to increase and the efficiency cannot be increased as compared with a motor with a core. Further, in the case of an axial gap type motor, a magnetic attraction force acts in the axial direction, so that the life of the bearing is shortened, and vibration is apt to occur in the axial direction, which causes the disk to oscillate.

On the other hand, in the radial gap type motor, magnetic attractive forces are generated in the radial direction and cancel each other out, so that no load is applied to the bearing, which is preferable in terms of life and stabilization of disk rotation. .

Therefore, as a disk rotation motor,
It must be of the radial gap type and small.

Therefore, the present invention realizes downsizing as a configuration in which the head and the windings of the armature core are arranged in parallel with the disk rotation axis, thereby realizing a disk that can be made smaller and thinner. An object is to provide a rotation motor.

[0018]

According to a first aspect of the present invention, there is provided a stator unit, and a rotor unit that rotates about a rotation axis with respect to the stator unit to integrally rotate a disk. It has a hub having an annular recess on the bottom surface side, has a multi-pole magnetized in the circumferential direction of the inner surface of the recess, has an annular permanent magnet that generates a magnetic flux substantially radially, and the stator portion has a straight line. A plurality of core pieces having a head and a neck whose circumferential length is shorter than that of the head along the shape axis, the axis is parallel to the rotation axis, and formed in an annular shape. In the arrangement state, the head part of each core piece is integrally molded with synthetic resin, and a plurality of core pieces are arranged in a ring.
Is fixed to it state, the head of each core piece is fitted into the annular recess of the hub, an armature core disposed side of the head portion to face the peripheral surface of the annular magnet, the The winding axis is parallel to the rotation axis, and the windings are provided on the necks of the core pieces, and the stator yoke connects the necks of the core pieces to each other. is there.

[0019]

According to a second aspect of the present invention, in the motor of the first aspect, the stator yoke is configured to also serve as an iron chassis base.

[0021]

[0022]

The structure in which the peripheral side surface of the head faces the peripheral side surface of the annular magnet acts to constitute a radial gap type motor.

The configuration in which the axis of the iron core portion is linear and the core portion is arranged with its axis parallel to the rotation axis acts to make the winding parallel to the rotation axis.

The configuration in which the winding axis is parallel to the rotation axis is compared with the case where the winding axis is radial.
The winding acts to reduce the diameter of a circle arranged in the circumferential direction.

The annular recess in the bottom surface of the hub according to the present invention acts to accommodate the annular permanent magnet and the head of the armature core. Integrally molded with the structures of the plurality of core sheets of a synthetic resin, for example, it acts to allow the use of core pieces formed by metal injection.

[0026]

[0027]

The structure in which the stator yoke also serves as the chassis base according to the third aspect operates so that a dedicated stator yoke is not required.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a first embodiment of a disk rotating motor according to the present invention will be described.
An embodiment will be described with reference to FIGS.

In FIG. 2, the disk file device 20 has a structure in which a 1.8 inch disk 22 and a disk rotation motor 23 are incorporated in an iron enclosure 21.

The enclosure 21 has a chassis base 2
1a and the cover 21b, and the external dimensions are the same size as the IC memory card (54 mm × 85.6 mm × 5 m
m).

A hub 24 has a pair of bearings 26 and 27 mounted on a fixed shaft 25 fixed to the enclosure 21.
Are supported rotatably. The center hole 22a of the disk 22 is fitted and fixed to the hub 24.

The hub 24 has an annular recess 28 formed on the lower surface thereof. The recess 28 forms an annular space 29 for housing the motor 23.

The hub 24 is made of iron, which is one of soft magnetic materials.

As described below, the motor 23 is of a radial gap type, an outer ring rotating type, and an inner rotor type.

The motor 23 comprises a rotor section 30 and a stator section 31.

Reference numeral 32 denotes a rotation axis of the rotor unit 30.

Reference numeral 33 denotes an annular permanent magnet,
Is configured.

As shown in FIG. 3, the annular permanent magnet 33 is radially magnetized to eight or twelve poles in the circumferential direction. The direction of the magnetization is radial as indicated by reference numeral 34. Since the hub 24 is made of iron, the annular permanent magnet 33
The hub 24 is directly fixed to the inner peripheral surface 35 of the annular concave portion 28. That is, the yoke for the annular permanent magnet 33 is also used as the inner peripheral portion of the hub, and the motor 23 has a small diameter correspondingly.

The stator section 31 includes an armature core 36, a coil 37, and a stator yoke (iron-type chassis base 2).
1a).

As shown in FIGS. 4A and 4B, the armature core 36 is fixed by a synthetic resin ring 39 in a state in which nine core pieces 38 are arranged at equal intervals in the circumferential direction. The structure is generally cylindrical.

As shown in FIG. 5, each core piece 38 has a head 38a and a narrower neck 38b along a linear axis 40, and has a total height of 2.3 mm. The configuration is as follows. Some core pieces have legs 38c at the lower end of neck 38b. The iron core piece 38 is manufactured by precision sintering such as metal injection or press molding, casting, or the like, and is made of silicon iron, and has a small iron loss.

The armature core 36 has the above-mentioned leg 38c as a chassis base (stator yoke) of the enclosure 21.
It is fitted on a concave portion (not shown) of 21a and fixed on the chassis base 21a. The chassis base 21a is formed by drawing an iron plate having the same thickness as the cover 21b and having a thickness of 0.5 mm, and also serves as a stator yoke of the motor of the present invention.

As shown in FIG. 2, the head 3 of each iron core piece 38
8a is fitted in the annular space 29 of the hub 24,
An inner peripheral side surface 38a-1 of the head portion 38a is opposed to an outer peripheral surface 33a of the annular permanent magnet 33 with a radial gap 41 therebetween.

As shown in FIG. 4, the opening angle θ of the head 38a
Is about 30 to 38 degrees.

The axis 40 of each core piece 38 is parallel to the rotation axis 32.

The above-mentioned armature iron core 36 is shown in FIG.
As shown in (B), the core piece 38 is set in a mold (not shown) and manufactured by insert molding in which a synthetic resin is injected.

The armature core 36 is composed of nine core pieces 3.
8 are integrated by a synthetic resin ring portion 39, have sufficient strength, and are easier to mount than when the iron core pieces 38 are mounted one by one to the chassis base.

In FIGS. 1 and 2, reference numeral 42 denotes a winding which is wound around the neck 38b.

Reference numeral 43 denotes an axis of the winding 42. The winding axis 43 coincides with the axis 40, and is parallel to the rotation axis 32.

As shown in FIG. 2, the winding 42 is located immediately below the annular recess 28 of the hub 24 and
It is provided in a space 44 between the chassis base 21a. 1 and 2, reference numeral 45 denotes a flexible printed circuit board, which is fixed on the chassis base 21a. The windings 42 are connected by the circuit board 45.

The neck 38b of the iron core piece 38 has a cross-sectional area as small as possible within a range where the magnetic flux is not saturated. As a result, the length of one turn of the winding 42 is shortened. As a result, the electric resistance value of the winding 42 is reduced, and the driving efficiency of the motor 23 is correspondingly increased.

Further, since it is not necessary to wind the winding directly on the iron core, it is possible to increase the number of turns by performing an alignment winding or the like. Further, it is also possible to apply a method other than the usual winding process such as a print coil.

Further, as shown in FIG.
3 and the armature core 36 are located outside the outer diameters of the outer races of the bearings 26 and 27, and
a.

The disk rotating motor 23 having the above structure is
It has the following effects.

Since the axes 40 and 43 are parallel to the rotation axis 32, the diameter D ₂ (12 mmφ) of the motor 23 can be reduced, and even when used for rotating a 1.8-inch small disk, as shown in the figure, The bearings 26 and 27 can be juxtaposed on the same plane.

Annular permanent magnet 33 and armature core 36
Because the head 38a of the core pieces 38 constituting the are accommodated in the space 29 within the annular recess 28 of the hub 24, may reduce the height H ₁ of the disk file device 20 in combination with the (high dimensioned H ₁ is specifically the same as the height of the IC memory card, a 5 mm).

Since the chassis base 21 a of the enclosure 21 also serves as the stator yoke of the stator section 31, the height H ₁ of the disk file device 20 can be reduced as compared with a configuration in which a stator yoke is separately provided.

Next, a modification of the components of the disk rotation motor 23 will be described.

Since the iron core piece 38 is small, the amount of material used is small, and it is possible to use expensive permendur. Since permendur has a large saturation magnetic flux density, the cross-sectional area can be reduced as compared with other materials, and the number of turns of the winding 42 can be increased.

FIG. 7 shows a modification of the iron core piece 38 shown in FIG. 5, which is manufactured by metal injection molding.

The head 38Aa of the iron core piece 38A is thicker at the center in the width direction than at the ends.

The neck 38Ab has a cylindrical shape. This makes it possible to increase the number of turns and reduce the resistance value, as compared with the winding 42 wound around the iron core piece 38 in FIG.

Instead of the annular permanent magnet 33 shown in FIG. 3, a polar anisotropic magnetized annular permanent magnet 33 A shown in FIG. 8 may be used. In this case, even if the hub 24 is non-magnetic such as aluminum, the hub 24 can be directly fixed to the hub without using a yoke.

The armature core 36 is formed by processing a soft magnetic steel strip by pressing, wire cutting, etching, or the like, and as shown in FIG. 9A, nine core pieces 38.
Obtains an iron core piece band 52 connected to a band portion 51 by a bridge portion 50, is formed into a cylindrical shape as shown in FIG. 3B, and is set in a mold in this state, and insert-molded. After that, it can also be manufactured by cutting the bridge portion 50.

According to this manufacturing method, the armature core 36
Is manufactured simply and accurately as compared with the method of individually setting the iron core pieces 38 in the mold as described above.

The armature core 36 can also be manufactured by the method shown in FIG.

First, by sintering a metal injection mold or the like, as shown in FIG. 7A, a plurality of core pieces 38 are connected by a bridge portion 55 and are arranged in a circumferential direction in a cylindrical armature core body 56. To manufacture.

The main body 56 is set in a metal mold and insert-molded to form a ring portion 39 made of synthetic resin as shown in FIG.

Finally, as shown in FIG. 7C, the bridge portion 55 is cut and removed.

According to this manufacturing method, it can be manufactured more simply and accurately than the above-described manufacturing method.

The armature core can also be manufactured by the method shown in FIG.

First, as shown in FIG. 7A, a tape-shaped thin plate 60 in which nine iron core pieces 38 are continuously formed is curved to form a cylindrical body 61 shown in FIG. I do.

Next, as shown in FIG. 7C, a plurality of cylindrical bodies 61 are combined concentrically and bonded with an adhesive.
An armature core 36A is manufactured.

In the armature core 36A, the space between the cylindrical bodies 6 is insulated by an adhesive, and the eddy current loss is small.

Further, the length of the thin plate 60 forming each cylindrical body 61 is changed by a length corresponding to the thickness of the thin plate, and each cylindrical body 61 fits exactly.

In place of the flexible printed board 45, a metal base board structure directly patterned on the chassis base 31a can be used.

Instead of the chassis base 31a, a dedicated stator yoke to which the armature core 36 is fixed may be provided.

Next, a disk rotating motor 23A according to a second embodiment of the present invention will be described with reference to FIG.

In the figure, parts corresponding to those shown in FIG. 2 are denoted by the same reference numerals.

The motor 23A has an armature iron core 36 on the inner peripheral side and an annular permanent magnet 33
Is provided on the outer peripheral side, and is a radial gap type, an outer ring rotating type, and an outer rotor type.

The outer peripheral side surface 38a-1 of the head 38a is connected to the inner peripheral side surface 3 of the annular permanent magnet 33 through the radial gap 41.
3b.

The armature core 36 and the annular permanent magnet 33 are
It is located outside the outer diameter of the outer ring of the bearings 26 and 27 and inside the center hole 22 a of the disk 22.

Next, a disk rotating motor 23B according to a third embodiment of the present invention will be described with reference to FIG.

In the figure, parts corresponding to those shown in FIG. 2 are denoted by the same reference numerals.

The motor 23B is a radial gap type, an inner ring rotating type, and an outer rotor type.

The bearings 26 and 27 are mounted on the chassis base 21a.
And is fixed in a cylindrical portion 21a-1 which is integral with.

The hub 24A has a rotary shaft 24A-1 at the center, and the central shaft 24A-1 is fitted and fixed to bearings 26 and 27.

The motor 23B is substantially the same as the motor 2
It has the same configuration as 3A.

[0090]

As described above, according to the first aspect of the present invention, the rotor section has a configuration in which the rotor is multipolarly magnetized in the circumferential direction and has the annular permanent magnet that generates the magnetic flux substantially radially. Yes, and the stator part is along a linear axis,
A plurality of core pieces having a head and a neck having a circumferential length shorter than that of the head are arranged in an annular shape such that the axis is parallel to the rotation axis. An armature core arranged with the side surface of the head of the piece facing the peripheral side surface of the annular magnet, and a winding provided on the neck of each core piece with the winding axis parallel to the rotation axis. In addition, since the configuration is such that the stator yoke connects the necks of the iron core pieces to each other, a radial gap type can be obtained and the size in the radial direction can be reduced. In addition, the rotor portion has a hub having an annular concave portion on the bottom surface side, and has an annular permanent magnet on the inner surface of the concave portion that is multipolar magnetized in the circumferential direction and generates magnetic flux substantially radially, and Since the head of the iron core piece is fitted into the recess, the disk rotating motor can be made thinner, and thus the disk file device can be made thinner. In addition, the armature core is formed by integrally molding a plurality of core pieces with a synthetic resin so that the plurality of core pieces are annular.
, The strength and accuracy of the armature iron core can be improved, and an iron core piece formed by, for example, metal injection can be used.

[0091]

[0092]

[0093]

According to the third aspect of the present invention, since both the stator yoke and the chassis base of the enclosure are used,
It is possible to reduce the height of the disk file device and to reduce the thickness.

[Brief description of the drawings]

FIG. 1 is a perspective view of a disk rotation motor according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a disk filing apparatus in which the disk rotating motor of FIG. 1 is incorporated.

FIG. 3 is a perspective view showing an annular permanent magnet in FIG. 1;

FIG. 4 is a view showing an armature core in FIG. 1;

FIG. 5 is a view showing one iron core piece;

FIG. 6 is a diagram illustrating armature core manufacturing.

FIG. 7 is a view showing a modification of the iron core piece.

FIG. 8 is a view showing a modification of the annular permanent magnet.

FIG. 9 is a view showing a second method of manufacturing the armature core.

FIG. 10 is a view showing a third method of manufacturing the armature core.

FIG. 11 is a view showing a fourth method of manufacturing the armature core.

FIG. 12 is a view showing a disk rotation motor according to a second embodiment of the present invention.

FIG. 13 is a view showing a disk rotation motor according to a third embodiment of the present invention.

FIG. 14 is a diagram showing an example of a conventional disk rotation motor.

FIG. 15 is a plan view of the disk rotation motor of FIG. 14;

FIG. 16 is a diagram showing another example of a conventional disk rotation motor.

[Explanation of symbols]

 Reference Signs List 20 disk file device 21 enclosure 21a chassis base (stator yoke) 21b cover 22 disk 23, 23A, 23B disk rotation motor 24, 24A hub 24A-1 rotation shaft 25 fixed shaft 26, 27 bearing 28 annular recess 29 annular space 30 Rotor part 31 Stator part 32 Rotation axis 33, 33A Annular permanent magnet 33a Outer side surface 33b Inner side surface 34 Magnetization direction 35 Inner peripheral surface 36 Armature core 37 Coil 38 Core piece (iron core) 38a Head 38a-1 Inner periphery Side surface 38a-2 Outer side surface 38b Neck 38c Leg 39 Ring portion 40 made of synthetic resin 40 Linear axis 41 Radial gap 42 Winding 43 Winding axis 44 Space 45 Flexible printed circuit board 50, 55 Bridge section 51 Band section 52 Iron core One band 56 Armature core body 60 Tape-shaped thin plate 61 Cylindrical body

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Keiji Ariga 1015 Ueodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Inside Fujitsu Limited (56) References JP-A-3-189957 (JP, A) JP-A-54-64212 (JP, A)

Claims (2)

(57) [Claims] 1. A rotor comprising: a stator portion; and a rotor portion which rotates about a rotation axis with respect to the stator portion to integrally rotate a disk, wherein the rotor portion has a hub having an annular concave portion on a bottom surface side. The inner surface of the recess has an annular permanent magnet which is multipolarly magnetized in a circumferential direction and generates a magnetic flux substantially radially, and the stator portion has a head along a linear axis, A plurality of core pieces each having a neck portion whose circumferential length is shorter than that of the head are arranged such that the axis is parallel to the rotation axis and arranged in an annular shape. Part is integrally molded with synthetic resin and fixed in a state where multiple iron core pieces are arranged in a ring
The armature core, in which the head of each core piece is fitted into the annular recess of the hub, and the side of the head is arranged to face the peripheral side of the annular magnet, and the winding axis thereof is is parallel to the rotation axis, the disc, characterized in that the above-mentioned windings provided on the neck of the core pieces, and become more configuration a stator yoke which connects the neck of the respective core pieces to each other Motor for rotation. 2. The stator yoke includes an iron chassis.
2. The structure according to claim 1, wherein said base is also used.
The disk rotation motor according to the above.