JPS62247749A - Axial clearance-type motor with built-in frequency generator - Google Patents

Abstract

PURPOSE:To prevent the increase of clearance length in the axial direction and to obtain large rotating torque, by shaping a conductive pattern for forming a comb-teethlike frequency generator in a filed magnet facing a multipolar magnet for a frequency generator. CONSTITUTION:In the center of a stator yoke 2 a bearing house 3 is fixed and a rotating shaft 5 is pivotably supported. On the under-side of the stator yoke 2 is fixed a flat annular ring-shaped field magnet 7. An FG pattern 8 for forming a comb-teethlike frequency generator is formed on the outside circumference of the underside of the field magnet 7. A plastic magnet 19 is integrally formed to the position opposite the FG pattern 8 face to face on the outside circumference between armature coils. To this plastic magnet 19 N and S poles magnetized in the axial direction is multipolarly magnetized in the circumferential direction in finer pitch to form a multipolarly magnetized magnet 20 for forming a frequency generator.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an axial gap type electric motor with a built-in frequency generator useful for use in spindle motors of portable 3.5-inch floppy disks and the like.

[Prior art and its problems] 3.5 inch micro floppy disk drive [M
FDD] and hard disks [HDD], axial gap type brushless motors are often used as their spindle motors.

Such an axial gap type brushless motor is very useful for use in spindle motors such as MFDDs and HDDs because the motor shape can be made thin and since it is a brushless motor, it has a long life.

Further, an axial gap type brushless motor used in a spindle motor such as MFDDOHDD has a built-in frequency generator in order to rotate the motor at a constant speed.

To explain a typical structure example of this axial air gap type brushless motor with a built-in frequency sporadic motor, one example is that the field magnet (main magnet) serves as a rotor, and the electric motor is mounted on the stationary side opposite to the rotor. A stator armature consisting of a group of child coils is disposed, and a printed wiring board on which a comb-shaped conductive pattern (hereinafter referred to as FG pattern) for forming a frequency generator is disposed is disposed to face the stator armature. It has been established.

Another typical axial gap type brushless motor, which is designed to obtain more frequency signals than this brushless motor, has an additional N in the field magnet.

A field magnet is used in which S magnetic poles are multipolarized at a fine pitch to form a multipolar magnetized portion for forming a frequency generator.

This brushless motor can obtain a frequency signal with better performance than the brushless motor described above, but since the field magnet is formed with a multi-pole magnetized part for forming a frequency generator, The efficiency of the brushless motor deteriorates because the magnetic flux of the field magnet weakens.

In addition, in the two typical axial gap type brushless motors mentioned above, it is necessary to arrange a printed wiring board with an FG pattern formed on the stator armature, but the thickness of this printed wiring board is equivalent to the axial magnetic field. Since the length of the air cap increases, the efficiency decreases accordingly and the motor becomes thicker in the axial direction.

Another typical axial gap type brushless motor is
A field magnet is disposed on the rotor yoke, and a multi-pole magnetized magnet for a frequency generator is disposed on the outer periphery of the field magnet, in which N and S magnetic poles are separately formed and magnetized at a fine pitch. A printed wiring board on which an FC pattern is formed is disposed on the fixed side facing the multipolar magnetized magnet.

Although this method does not increase the length of the air gap, it has the disadvantage that the brushless motor becomes longer in the radial direction.

In addition, in the typical axial gap type brushless motor mentioned above,
Since the field magnet rotates, an expensive magnetoelectric conversion element such as a Hall element or Hall IC is used to detect the position of the field magnet, and based on the signal from the element,
'1! In order to switch the energization of the coil in a predetermined direction, a commutation circuit using a multi-shell 1'-.9 body must be used, which has the disadvantage of being expensive.

If you want to obtain an axial air gap motor with a built-in frequency generator at low cost, you should use a rectifier that uses brushes and a commutator to rectify the current, where the armature is the rotor and the field magnet is the stator. It is desirable to adopt a commutator axial air gap type motor.

In particular, in terms of longevity, it is sufficient to guarantee a certain culmness, and for use in equipment that must be formed at low cost, 1
In many cases, it is more advantageous to use a commutator-shaped air gap type motor as described in Item 4.

However, in conventional axial air gap motors with built-in frequency generators, white and black (or two other colors with different reflectances may be used) are alternately formed on the outer periphery of the rotating armature. In most cases, this is detected using an optical sensor such as a photoreflector.

According to such a method of detecting the rotational speed of the electric motor using an optical sensor, it is necessary to take sufficient measures to shield the electric motor from light, which has the disadvantage that the structure of the electric motor becomes complicated.

Furthermore, since it is necessary to provide an optical sensor on the outer periphery of the rotating armature, there is a drawback that the responsibility of the electric motor increases.

In addition, it is time-consuming to form two types of coloring on the outer circumference of the rotating armature, and it is expensive to form two types of coloring at very small intervals (if it is expensive, it is better to use a brushless motor structure. (This has many advantages), and usually the two types of coloring are not formed at a fine pitch.

For this reason, it was not possible to construct an axial air gap type motor with a built-in frequency generator with high precision.

In addition, in many cases, light-emitting diodes are used as optical sensors, but such light-emitting diodes have short lifespans and malfunction due to external noise signals. It was not possible to form an electric motor.

Therefore, the present inventor first molded a rotating armature with a plastic magnet, and attached multiple axially oriented N and S magnetic poles at fine pitches in the circumferential direction to the plastic magnet on the outer periphery of the rotating armature. Obtaining an axial gap type electric motor with a built-in frequency generator which is magnetized to form an FG magnet,
Eliminates the drawbacks of the conventional method.

However, it was difficult to mold the entire rotating armature with plastic magnets.

The difficulty in molding the entire rotary armature with a plastic magnet is due to the fact that the plastic magnet is molded under greater pressure than plastic.

In addition, when an FG magnet is formed on the outer periphery of the rotating armature, and when a printed wiring board with an FG pattern formed thereon is disposed on the FG magnet with an axial gap in between, it is necessary to prevent the diameter of the motor from increasing. To achieve this, the outer shape of the field magnet must be reduced by the width of the circumferential conductor portion that does not contribute to the torque generated by the armature coil.

In this way, it is usually okay to reduce the diameter of the field magnet i by the width of the conductor part in the circumferential direction depending on the generated torque, but in reality, the diameter of the electric machine is small. The intersection of the conductor part that does not contribute to the generated torque of the armature coil and the conductor part that contributes to the generated torque greatly contributes to torque generation, so when the diameter of the field magnet is made smaller, The disadvantage is that the torque decreases accordingly.

In addition, when installing an FG magnet at a position between the armature coils or at a position within the frame cavity of the armature coil, this FG magnet
A printed wiring board with an FG pattern formed thereon must be placed in the field magnet portion facing the magnet, and the axial gap length increases by the thickness of the printed wiring board, so The drawback is that the magnetic flux weakens, making it impossible to obtain large rotational torque.

[Problems to be solved by the invention] The present invention has been made to solve the above-mentioned problems, and is made by magnetizing a rotary armature with multi-pole N and S magnetic poles of axially oriented 4 magnets along the circumferential direction. A multi-pole magnetized magnet for forming a generator is formed, and a comb-like conductive pattern for forming a frequency bush generator is formed on the stationary side through an axial gap with the multi-polar magnetized magnet for forming a frequency generator. Even if an axial gap type motor with a built-in frequency generator is formed, the motor will not become thick in the axial direction, the air cap will become large and the efficiency will deteriorate, or the motor will not become large in the radial direction. It is an object of the present invention to make it possible to easily and inexpensively form an axial gap type electric motor with a built-in frequency generator like Hoko.

rMeans for achieving the object of the present invention] The object of the present invention is to rotate a field magnet having a plurality of N and S magnetic poles, and to provide an armature that faces the field magnet through an axial gap. In an axial air-gap type electric motor as a rotor, the armature is provided with a multi-pole magnetized magnet for a frequency generator in which N and S magnetic poles of axially oriented magnetization are magnetized in a circumferential direction, and the armature rotates integrally. An axial gap type electric motor with a built-in frequency generator in which a conductive pattern for forming a comb-like frequency generator is formed on the field magnet facing the multi-pole magnetized magnet for the frequency generator. This is achieved by providing

[First Embodiment of the Present Invention] FIG. 1 is a longitudinal sectional view of an axial air gap type motor 1 with a built-in frequency generator as a first embodiment of the present invention, and FIG. 2 is a perspective view of a rotating armature. Figure 3 shows the conductive pattern for forming a frequency generator (
FIG. 2 is a bottom view of a field magnet in which a FG pattern (hereinafter referred to as an FG pattern) is formed.

Hereinafter, a first embodiment of the present invention will be described mainly with reference to FIGS. 1 to 3.

Referring to FIG. 1, an axial gap type electric motor l with a built-in frequency generator has a bearing house 3 fixed to the center of a stator yoke 2, and bearings 4-1, 4-2 on the inner periphery of the bearing house 3. and the bearing 4-1.4-2
The rotary shaft 5 is rotatably supported by the rotary shaft 5.

A collar 6 is interposed between the bearings 4-1 and 4-2.

A flat annular field magnet 7 as shown in FIG. 3 is fixed to the lower surface of the stator yoke 2. As shown in FIG. The field magnet 7 is a four-pole ring-shaped magnet in which the N and S magnetic poles are alternately magnetized at equal opening angles of 90 degrees.

A comb-like FG pattern 8 for forming a frequency generator is formed on the outer periphery of the lower surface of the field magnet 7, as shown in FIG. In forming the FG pattern 8,
As shown in FIG. 4, it is necessary to form an insulating layer 9 on the lower surface of the field magnet 7 in advance. In this case, the insulating layer 9 may be formed at least only at the cylinder where the FG pattern 8 is formed, but since it is easier to insulate the entire lower surface, in this embodiment, the lower surface of the field magnet 7 is All shall be insulated.

The stator yoke 2 facing the through hole in the center of the field magnet 7 has brushes 10-1, 10-2 at an opening angle of 90 degrees.
(See Figures 1 and 5).

The brush 10-1 is connected to a positive power terminal 22-1 (see FIG. 5) via a lead wire (not shown), and the brush 10-2 is connected to a negative power terminal 22-1 (see FIG. 5) via a lead wire (not shown). 22-2 (see Figure 5).

The rotor yoke 14 is configured to rotate integrally with the rotating shaft 5 through a screw opening.

As shown in FIG. 2, a coreless rotating armature 15 is fixed and shifted on the upper surface of the rotor yoke 14 so as to rotate relative to the field magnet 7.

The coreless rotating armature 15 includes three air-core armature coils 16-1. . . , 16-3 are arranged at regular intervals so as not to overlap with each other, and are molded with plastic 17 to form an integral disc-shape.

In addition, the armature coil 16-1. The circumferential conductor portions 16b and 16c of @..., 1B-3 are conductor portions that do not contribute to the generated torque. Radial conductor portions 16a, 16a''
is a conductor that approaches the source 4I.

Axial gap type 'F+! Motivation +! In order to form a machine with good performance, the mechanical running coils 16-1Φ and 16-3 are set at the opening angle ( In this case, the conductor portion 16a.

16a' is selected as an air-core type having a width equal to the width of one magnetic pole of the field magnet 7.

Incidentally, since the opening angle of one magnetic pole of the field magnet 7 is 90 degrees, the armature coils 16-1°..., 16-3
The opening angle of the armature coil is 90 degrees, and the armature coil 16-
1. -Φ conflicts, 16-3 are arranged at equal intervals of 120 degrees.

When molding the above-mentioned armature coil 1B-1, . . . fist, 16-3 with plastic 17, armature coil 1B-1,
. . . Even the air core portion 18 of 16-3 does not need to be molded with plastic.

Armature coil 16-1. -..., when molding 16-3 with plastic to form a disk shape, armature coil 1
6-1. . . , a plastic magnet 19 is integrally formed by a two-color molding method or the like at a position facing the FG pattern 8 on the outer periphery between 16-3.

As shown in FIG. 2, the plastic magnet 19 is a multi-pole magnetized magnet (20) for forming a frequency generator by polarizing N and S magnetic poles with axial orientation magnetization in the circumferential direction at a fine pitch. (hereinafter referred to as FG magnet).

In this case, it goes without saying that the multipole magnetization of the plastic magnet 19 may be performed after the plastic magnet 19 is integrated with the rotating armature 15, or may be performed before the integration.

Six commutator pieces 21-1 are arranged in the center of the rotating armature 15.
．． - A flat commutator 21 consisting of Φφ and 21-6 is fixed, and the brush 10-1.10-
In sliding contact with 2, a rectifying effect is performed.

Note that the FG pattern 8 has a radial conductor portion 8a that attracts power generation, and this conductor portion 8a connects to the FG magnet 2.
Since an electromotive force is generated by rotating and interfering with the N and S 'm poles of 0, a frequency signal corresponding to the rotational speed can be obtained from the terminal 8b.

Incidentally, even when the three FG magnets 20 are separated as in this embodiment, the FG pattern 8 is formed over the entire circumference, so the frequency generator is of the all-circumference integral type, so the accuracy is low. A frequency signal for a good rotation speed can be obtained.

This frequency signal is amplified and rectified and converted into a speed control voltage using an F/V conversion circuit. Based on this voltage, the electric motor
can be controlled at constant speed.

Figure 5 shows the field magnet 7 (7-1° fist e・, 7-4
) and armature coils 1B-1°@Φ・, 1B-3 are shown.

As is clear from this development diagram, three armature coils 1B
-1, 1B-3 are arranged at equal intervals so as not to overlap each other.

One terminal of the armature coil 16-1 is connected to the commutator piece 21-
1, and the other terminal is commonly connected to the other terminals of armature coil 16-2 and armature coil 16-3. One terminal of the armature coil 16-2 is connected to the commutator piece 2
1-3. One terminal of armature coil 16-3 is connected to commutator piece 21-2.

That is, this embodiment has a Y-type connection.

In addition, in the state shown in the figure, the brush 12-1 is connected to the commutator piece 21-2.
The brush 12-2 is in sliding contact with the commutator piece 21-4.

The brush 12-1 is connected to the positive power terminal 22-1, and the brush 22-2 is connected to the negative power terminal 22-2.

Therefore, in this state, the armature coil 1
6-2 and 16-3, a current flows in the direction of the arrow, and the effective conductor portions 16a of armature coils 16-2 and 16-3,
16a', a rotational torque as indicated by B'' is generated in the direction of the arrow, and as a whole, a rotational torque as indicated by B is generated in the direction of the arrow, and the rotating armature 15 rotates in the same direction.

[Second Embodiment] Referring to FIGS. 6 and 7, an axial gap type electric motor l with a built-in frequency generator according to a second embodiment of the present invention.

I will explain about it. Note that parts common to those in FIG. 1 are given the same reference numerals. The electric motor 1° of this embodiment does not have the rotor yoke 14 unlike the electric motor 1 described above, but has a rotary armature 15° directly integrated with the rotating shaft 5 for rotation. In addition, the code|symbol 23 is a motor bracket made of a magnetic material. Therefore, the rotating armature 15°
is completely coreless. The rotating armature 15° uses three air-core armature coils 16-1, Φ, and 1B-3 in the same manner as described above, and molds them with plastic 17 to form a disk shape, and furthermore, the outer periphery is The armature coil 16-1.・φ−, 1
An FG magnet 20' is formed on the outer periphery of the magnet 6-3.

The rotating armature 15° faces the field magnet 7 on which the FC pattern 8 shown in FIG. 3 is formed, with an axial gap interposed therebetween. Therefore, the FG magnet 20' and the FG pattern 8 form a frequency generator.

C. Third Embodiment of the Present Invention] A third embodiment of the present invention will be described with reference to FIGS. 8 and 9. In the axial gap type motor 1' with a built-in frequency generator of this embodiment, the armature coil 16-1. ...,
An FG magnet 20° is formed in the frame cavity 23 of 1B-3, and a field magnet 7'' is located at a position facing the field magnet 20'' through an axial gap.
A G pattern 8' is formed. Furthermore, FG magnet 2
0'' is fixed to the rotor yoke when the rotating armature 15° uses a rotor yoke.
It may be formed integrally with '. However, in this embodiment, the outer circumference of the armature coil 16-1°φφ-, 1B-3 is molded with plastic 17, and at the same time the armature coil 16-1
゜-..., a plastic magnet 119 is molded in the frame cavity 23 of 1B-3 by two-color molding, and the plastic magnet 19 is axially oriented magnetized with N,
The FG magnet 20'' is formed by multi-pole M magnetic poles in the circumferential direction at a fine pitch.This FG magnet) 2
0'' and the FG pattern 8' form a frequency generator.

[Other Examples] In the above example, the FG magnet is 20.20'.

20'' is magnetized after molding a plastic magnet 19, but the FG magnet 20 is multi-pole magnetized in advance. 20'', 20'' is molded with plastic 17 and rotating armature 15°, 15°, 15 It may be integrated into "".

Further, although the plastic magnet 19 is used as the FG magnet 20, 20', 20°, there is no need to limit it to this, and other types of magnets may be used.

Also, it is desirable that the FG magnets 20.20' and 20'' are integrated with the armature coils 16-1. -2.16-2 and 16-3.16-
It is also possible to fix between the two rotor yokes of 3 and 16 to 1.

For example, when using the rotor yoke 14, the armature coils 1B-1, . . . This is because it can be done in the same way as if it were integrated with the plastic 17.

In addition, in the third embodiment, the FG magnet was formed only in a part of the hollow part in the frame of the armature coil, but the whole hollow part in the frame was molded with a plastic magnet, multipole magnetized, and the FG magnet was formed in only a part of the hollow part in the frame of the armature coil. A magnet may also be formed.

In addition, in the above example, a four-pole field magnet 7 and three armature coils 1B-1, ---, 1B-3 are used, but it goes without saying that the invention is not limited to this. .

It goes without saying that armature coils are also applicable to so-called sheet coils and printed coils.

[Effects of the Invention] Although the axial air gap motor with a built-in frequency generator of the present invention is a commutator axial air gap motor, it has a frequency generator that uses an FG magnet and an FG pattern similar to an axial air gap brushless motor. It has the advantage that it can be built in rationally, and there is no need to increase the size of the air cap and degrade efficiency, increase the thickness of the motor in the axial direction, or create an axial gap type motor that is long in the radial direction.

Furthermore, since the electric motor of the present invention is a commutator axial gap type motor, it can be mass-produced at a lower cost than an axial gap type brushless motor even if it has a built-in frequency generator.

Furthermore, the electric motor of the present invention has the advantage that it is shorter in the radial direction than the conventional commutator motor with a built-in frequency generator, has a simple structure, and can be mass-produced at low cost.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of an axial gap type electric motor with a built-in frequency generator as a first embodiment of the present invention, FIG. 2 is a perspective view of a rotor rotating armature, and FIG. 3 is a comb-shaped frequency scattering'. FIG. 4 is a bottom view of a field magnet with a conductive pattern formed thereon for forming a FLF machine, and FIG. The figure is a developed view of a field magnet and an armature coil group, Figure 6 is a longitudinal cross-sectional view of an axial air gap type motor with a built-in frequency generator showing a second embodiment of the present invention, and Figure 7 is a rotation of the same motor. A plan view of the armature, FIG. 8 is a longitudinal sectional view of an axial air gap type motor with a built-in frequency generator as a third embodiment of the present invention, and FIG. 9 is a perspective view of the rotating armature and field magnet of the same motor. It is. [Explanation of symbols] 1.1', 1"Φ-・Axial gap type electric motor with built-in frequency generator, 2...e stator yoke, 31e bearing house, 4-1.4-2-11-bearing, 5...・0 rotation axis, 6・fist・collar, 7 working fist・rotation axis, 8.8°・・conductive pattern for medium frequency scatter generator formation (FG pattern), 9
・・Fist insulation layer, 10-1.10-2Φ・・Brush, 14
...Rotor yoke, 15.15". 15°° coreless rotating armature, 16-1° --@
, 1B-3---armature coil, 16a. 16a'es・Conductor portion contributing to generated torque, 16b,
16cm...Conductor part that does not come close to the generated torque, 17. φ plastic, 18.. Air core part, 19.. Jar plastic magnet, 20° 20', 20" Φ0. Multipolar magnetized magnet for forming a frequency generator. (FG Magnent)
, 21・Meeting・Commutator, 21-1 , Φ-φ21-6・Fist・Commutator piece, 22-1-・Positive side power terminal, 22-2-
Bone/negative side power supply terminal, 23... hollow part within the frame.

Claims (1)

[Claims] (1) Axial direction in which a rotor is a field magnet having a plurality of N and S magnetic poles, and an armature that faces the field magnet face-to-face through an axial gap In the air-gap type electric motor, the armature is provided with a multi-pole magnetized magnet for a frequency generator in which N and S magnetic poles of axially oriented magnetization are magnetized in a circumferential direction so that the armature rotates as a unit. This is an axial gap type electric motor with a built-in frequency generator, in which a comb-like conductive pattern for forming a frequency generator is formed on a field magnet facing a multi-pole magnetized magnet for a frequency generator. (2) The above-mentioned multi-pole magnetized magnet for a frequency generator is formed integrally with the armature when the armature coil group is molded with plastic and formed into a disk shape, as claimed in claim (1). Axial gap type electric motor with a built-in frequency generator as described in . (3) The above-mentioned multi-pole magnetized magnet for a frequency generator has a group of armature coils molded with plastic to form a disk shape, and positions between the armature coils are molded with a plastic magnet, and the plastic magnet is A built-in frequency generator according to claim (1) or (2), which is formed by multi-pole magnetizing N and S magnetic poles of axially oriented magnetization along the circumferential direction. Air gap type electric motor. (4) The multi-pole magnetized magnet for the frequency generator is integrally formed on the outer periphery of the armature, as claimed in claim (1).
The axial air gap electric motor with a built-in frequency generator according to item (2) or item (2). (5) The multi-pole magnetized magnet for a frequency generator formed on the outer periphery of the armature is made by molding the armature coil with plastic, molding a plastic magnet on the outer periphery, and applying axial orientation to the plastic magnet. An axial gap type electric motor with a built-in frequency generator as set forth in claim (4), which is formed by multi-pole magnetizing N and S magnetic poles along the circumferential direction. (6) The frequency generator according to claim 1 or 2, wherein the multi-pole magnetized magnet for a frequency generator is formed in an internal cavity position of an armature coil. Built-in axial gap type electric motor. (7) The multi-pole magnetized magnet for a frequency generator formed in the internal cavity position of the armature coil is formed by molding the outer periphery of the armature coil with plastic and placing it in the internal cavity position of the armature coil. The frequency according to claim (6), which is formed by molding a plastic magnet, and magnetizing the plastic magnet with multiple axially oriented N and S magnetic poles along the circumferential direction. Axial gap type electric motor with built-in generator. (8) The comb-shaped conductive pattern for forming the frequency generator is formed after insulating the surface of the field magnet, according to any one of claims (1) to (7). Axial gap electric motor with built-in frequency generator as described.