JP2983409B2 - Three-phase drive DC 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 flat three-phase DC motor.

[0002]

2. Description of the Related Art In recent years, electronic devices have been reduced in size, and there has been a strong demand for smaller and thinner motors used as drive sources for the respective devices. Further, as the driving power supply decreases, a motor having a higher torque than now is required.

A ring-shaped magnet having 2p (where p is an integer of 2 or more) magnetic poles on a plane, and 3m (where m is an integer of 1 or more) facing this magnet
In a three-phase drive DC motor having a coil in which spiral unit coil poles are arranged in a plane, for example, as described in the embodiment of JP-A-63-87145, 2p = 8 and 3 m = 6 combinations are common. This configuration is also referred to as a phase transition method, and the combination of the magnetic pole 2p of the magnet and the number of spiral unit coil poles 3m is the same as the conventional 2p = 12 and 3m = 9 or 2p = 16 and 3m = 12. In this case, 2p: 3m = 4: 3.

[0004]

However, in order to increase the torque in the three-phase drive DC motor having the above configuration, it is necessary to increase the number of turns in the spiral unit coil pole. However, increasing the number of coils increases the coil pole or increases the thickness, which hinders miniaturization and thinning.

In view of the above, an object of the present invention is to increase the torque of a motor without increasing the coil poles or increasing the thickness of the motor, thereby increasing the output of a small and thin three-phase drive DC motor. It is to provide a motor.

[0006]

To achieve the above object, the present invention provides a ring-shaped magnet having 2p (where p is an integer of 4 or more) magnetic poles on a plane, and a ring-shaped magnet facing the magnet. And 3 m (where m is an integer of 3 or more) flat coil in which spiral unit coil poles are arranged in a plane, and the number of poles of the magnet is 2p and the number of spiral unit coil poles is 3 m Is 2p = 2 ×
(3k + 1) and 3m = 3 × (2k + 1), or 2p =
2 × (3k + 2) and 3m = 3 × (2k + 2) (however,
k is an integer of 1 or more).

Further, the present invention is preferably characterized in that, in the spiral unit coil pole, m unit coil poles having the same phase are arranged adjacent to each other.

[0008]

According to the present invention, the number of magnet poles is 2p (however,
p is an integer of 4 or more) and the number of spiral unit coil poles is 3 m (where m is an integer of 3 or more), and 2p = 2
× (3k + 1) and 3m = 3 × (2k + 1) or 2p
= 2 × (3k + 2) and 3m = 3 × (2k + 2) (k is 1
(The above integer), the number of coil poles can be larger than the number of magnet poles. This means that the number of poles for generating torque is increased when the ratio of the number of magnetic poles to the number of coil poles of the conventional phase transition method is 4: 3. Therefore, according to the present invention, it is possible to obtain a high-torque three-phase drive DC motor having the same size as the conventional system.

Further, according to the present invention, when the same torque is generated, a smaller and thinner three-phase drive DC motor can be obtained.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings.

1 to 4 show the structure and characteristics of a three-phase drive DC motor according to an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of the three-phase drive DC motor, and FIG. 2 is a rotor of the motor. FIG. 3 is a plan view of a magnet, FIG. 3 is a plan view of a flat coil for a DC brushless motor of the motor according to the present invention, and FIG. 4 is a graph showing output characteristics of a three-phase drive DC motor of the present embodiment.

In FIG. 1, reference numeral 11 denotes an annular flat rotor magnet, 12 denotes a rotor plate having a flange on its outer periphery, 13 denotes a sleeve, 14 denotes a rotating shaft, 15 denotes a housing, and 16 denotes a rotating shaft 14. Bearing, 17 is the rotating shaft 1
Reference numeral 4 denotes a pivot receiver for supporting the tip, reference numeral 18 denotes an opposing yoke, and reference numeral 19 denotes a thin annular flat coil.

As shown in FIG. 2, the rotor magnet 11 has eight magnetic poles 1S and 1N in which N and S poles are alternately and equally magnetized in the circumferential direction. 1S is an S pole magnetic pole, and 1N is an N pole magnetic pole. One main surface of the rotor magnet 11 is fixed to the rotor plate 12. This rotor plate 12 is fixed to a rotating shaft 14 via a sleeve 13. One end of the rotating shaft 14 is pivotally connected to a bearing 16 fixed to a center hole of the housing 15, and the other end is connected to a pivot receiver 17.
Are attracted to the opposing yoke 18 by the magnetic force of the rotor magnet 11. On the other main surface of the rotor magnet 11, a flat coil 19 is arranged between the rotor magnet 11 and the opposing yoke 18 so as to face the rotor magnet 11 at a predetermined interval.

As shown in FIG. 3, a three-phase driving flat coil 19 used in this embodiment has nine spirally-shaped coil poles 4a to 4i arranged substantially evenly along a circumferential direction on one plane. Is done. Here, if 3A is a U-phase input terminal, 3B is a V-phase input terminal, and 3C is a W-phase input terminal, the coil poles 4a, 4b and 4c are U-phase, and the coil poles 4d, 4e and 4f are V-phase. , The coil poles 4g, 4h, and 4i become the W phase, the U-phase coil poles 4a, 4b, and 4c are arranged adjacently between the input terminals 3A and 3B, and the V-phase coil poles 4d, 4e, and 4f are input. The W-phase coil poles 4g, 4h, and 4i are arranged adjacently between the input terminals 3C and 3A. Then, the centers of the coil poles 4c, 4f, and 4i are buried along the edge (circumferential edge) of the through hole or connected by an electric wire shown by a broken line disposed on the back surface.

FIG. 4 shows a torque output characteristic of the motor according to the present embodiment. FIG. 4A shows a back electromotive force curve obtained by the U-phase coil pole 4a. Assuming that the peak value of the back electromotive force obtained from the coil pole is 1, the peak value of this output waveform is 1. FIG. 4 (b)
Is a back electromotive force curve obtained by the above-mentioned U-phase coil pole 4b. The peak value of this output is 1, but the back electromotive force curve obtained by the coil pole 4a of FIG. There is a phase shift of (1/9) π. (C) of FIG.
This is a back electromotive force curve obtained from the U-phase coil pole 4c. The peak value of this output is 1, but FIG.
(1) to the back electromotive force curve obtained from the coil pole 4b
/ 9) There is a phase shift of π. FIG. 4D shows a back electromotive force curve obtained from all of the U-phase coil poles (4a, 4b, and 4c), the peak value of which is 2.879, and the phase of which is shown in FIG. Same as b).

The V-phase and W-phase are considered in the same manner as the U-phase, and the back electromotive force curve synthesized by shifting the phase by an electrical angle (２) π for three-phase driving is shown in FIG. (E)
And the peak value of the output is 2.879.

Next, in order to more clearly show the difference between the configuration of the present invention and the output characteristics of the conventional example, the configuration and output characteristics of the conventional example will be described with reference to FIGS. The cross-sectional structure of the conventional three-phase drive DC motor is the same as that of FIG. 1, and the configuration of the rotor magnet 11 is also the same as that of FIG.

FIG. 5 is a plan view of a three-phase driving coil in which the flat coil 19 is of a conventional phase shift type, in which six coil poles 2a to 2f are arranged on one plane. Here, 1A is a U-phase input terminal, 1B is a V-phase input terminal, 1
If C is a W-phase input terminal, coil poles 2a and 2d
The phase, the coil poles 2b and 2e are the V phase, the coil poles 2c and 2f are the W phase, and the U, V, and W phase coil poles are sequentially arranged in the circumferential direction. That is, the in-phase coil poles (for example, 2a and 2d) are disposed facing each other at point-symmetric positions, and the centers of the respective in-phase coil poles are connected by electric wires shown by broken lines.

In the conventional arrangement of unit coil poles in the case where the number of magnetic poles of the rotor magnet 11 is different, the arrangement is performed in the same manner as in FIG. 5, so that the number of magnetic poles is 2p and the number of spiral unit coil poles is Is 3m, when 2p = 4, 3
3m = 6 when m = 3, 2p = 8, 3m = 9 when 2p = 12, 3m = 12 when 2p = 16, 2p = 2
3m = 15 when 0, 3m = 1 when 2p = 24
Conventionally, the relationship is 2p: 3m = 4: 3, such as 3m = 24 when 8, 2p = 32.

FIG. 6A shows the U-phase coil pole 2 shown in FIG.
If the peak value of the back electromotive force obtained from one coil pole is assumed to be 1, the peak value of FIG. FIG. 6B is a back electromotive force curve obtained from the U-phase coil pole 2d in FIG.
The peak value of the output is 1 as in FIG. FIG.
(C) shows all coil poles (2a and 2a) of the U-phase in FIG.
This is the back electromotive force curve obtained in d), and the peak value of the output is 2. The V-phase and W-phase are considered in the same manner as the U-phase, and the electrical angle is (2/3) π for three-phase driving.
The back electromotive force curve synthesized by shifting the phase is shown in FIG.
And the peak value of the output is 2.

The number of magnetic poles of the rotating magnet with respect to the conventional flat coil of FIG. 5 is 2p = 8, and the output peak value at that time is 2 as shown in FIG. 6 (d). The peak value is 1/4 of the number of magnetic poles. The same applies to other conventional flat coils composed of unit coils having different numbers of magnetic poles, and the peak value of the combined back electromotive force is １ ／ of the number of magnetic poles.

As described above, when the rotating magnets having the same magnetic poles are used and FIG. 4E of the embodiment of the present invention is compared with FIG. 2.87 compared to the conventional coil
It can be seen that a counter electromotive force of 9/2 = 1.439 times is obtained. That is, according to the present invention, a torque of 1.439 times can be generated. This is because the conventional coil pole number 3m is 2p: 3m in relation to the magnet pole number 2p.
= 4: 3, and thus was always less than the magnet pole number 2p, but the coil pole number 3m according to the present invention is 2p = 2 × (3k + 1) = 6k + 2 and 3m = 3 as described later.
× (2k + 1) = 6k + 3 or 2p = 2 × (3k +
1) = 6k + 4 and 3m = 3 × (2k + 2) = 6k + 6
(K is an integer of 1 or more), so that the number of coil poles is 3 m, which is one or two more than the number of poles 2p of the magnet.

The number of poles of the magnet is 2p and the number of coil poles is 3.
In addition to the present embodiment shown in FIGS. 2 and 3, the combination with m is 10 poles-12 coil poles, 14 poles-15 coil poles, 1
6 poles-18 coil poles, 20 poles-21 coil poles, 22 poles-
There are 24 coil poles and the like.

FIG. 7 shows the arrangement of the magnetic poles of a ring-shaped rotor magnet having 2p = 10 poles, and FIG. 8 shows the configuration of a flat coil according to another embodiment of the present invention using the rotor magnet of FIG. Is shown. This example shows an example of 10 to 12 coil poles, where A is a U-phase input terminal, B is a V-phase input terminal, and C is a W-phase input terminal.
b, c, d are U-phase, coil poles e, f, g, h are V-phase, coil poles i, j, k, l are W-phase, and U-phase coil poles a, b, c, d are input. The V-phase coil poles e, f, g, and h are arranged adjacently between terminals A and B, and the V-phase coil poles i, j, and k are arranged adjacently between input terminals B and C. , L
Are arranged adjacently between the input terminals C and A.

FIG. 9 shows a back electromotive force curve of the embodiment of FIG. FIG. 9A shows the back electromotive force curve obtained from the U-phase coil pole a. If the peak value of the back electromotive force obtained from one coil pole is 1, the peak value of this output waveform is 1. Become. FIG. 9B is a back electromotive force curve obtained from the U-phase coil pole b. The peak value of this output is 1, and the back electromotive force curve obtained from the coil pole a shown in FIG. There is a phase shift of (2/12) π. FIG. 9C shows a back electromotive force curve obtained from the U-phase coil pole c. The peak value of this output is 1, and the back electromotive force curve obtained from the coil pole b shown in FIG. 9B. (2/1
2) There is a phase shift of π. FIG. 9D shows a back electromotive force curve obtained from the U-phase coil pole d. The peak value of this output is 1, and the back electromotive force curve obtained from the coil pole c shown in FIG. 9C. There is a phase shift of (2/12) π. FIG. 9E shows a back electromotive force curve obtained from all of these U-phase coil poles (a, b, c, and d).
The peak value is 3.346.

The V-phase and W-phase are considered in the same manner as the U-phase. For the three-phase driving, the back electromotive force curves synthesized by shifting the phase by (2/3) π in electrical angle are shown in FIG. (F)
And the peak value of the output is 3.346.

The composite peak value in the case of the conventional 12-pole-9-coil pole is 3, which is 3.34 in this embodiment shown in FIG.
6 is much larger than this.

In the embodiment of the present invention shown in FIGS. 3 and 8, in order to make the wiring between the coil poles advantageous,
Although the coils of the same phase are adjacent to each other, the present invention is not limited to this. The coils may be moved to and arranged at substantially the same electrical angle. FIG. 10 shows an example of 10 poles to 12 coil poles in which the in-phase coil poles are not adjacent to each other. In this case, for the U phase, terminal A → coil pole a → b → c → d
And for the V phase, terminal B → coil pole f → g → h
→ e, and for W phase, terminal C → coil pole i → j
→ k → l, and the coil poles d, e and l are connected via a common wiring. The output characteristic is the same as that of the embodiment of FIG. 8, and is the same as that of FIG.

FIG. 11 shows an arrangement of flat coils according to another embodiment of the present invention. FIG. 11 shows a flat coil in which the number of magnetic poles is 2p = 14, the number of coil poles in one plane is 3m = 15, that is, 14 poles-15 coil poles. In the case of the embodiment of FIG. 3 described above, since the number of poles is 8-9, the combination of the number of magnet poles 2p and the number of spiral unit coil poles 3m is as follows.
This is the case where k = 1 in the general formulas of 2p = 2 × (3k + 1) and 3m = 3 × (2k + 1). In the case of the embodiment of FIG. This is the case when k = 2. If k is further increased, k
= 3 20 poles-21 coil poles, k = 4 26 poles-2
7 coil poles, 32 = 33 coil poles at k = 5,
These combinations can be realized by an arrangement method as shown in FIGS.

FIG. 12 shows an arrangement of flat coils according to still another embodiment of the present invention. FIG. 12 shows the number of magnetic poles 2p = 16,
The flat coil when the number of coil poles on one plane is 3 m = 18 is shown. In the case of the embodiment shown in FIGS.
Since there are 12 coil poles, the combination of the number of magnet poles 2p and the number of spiral unit coil poles 3m is 2p = 2 ×
Although k = 1 in the general formula of (3k + 2) and 3m = 3 × (2k + 2), in the case of the embodiment of FIG.
Since there are eight coil poles, this corresponds to the case where k = 2 in the general formula. When k is further increased, at k = 3, 22 poles −
24 coil poles, k = 4, 28 poles-30 coil poles, k =
5 has 34 poles-36 coil poles, and these combinations can be realized by the arrangement method as shown in FIGS.

As described above, in the present invention, the number of coil poles is 3 m, which is one or two more than the number of poles 2p of the magnet. Next, Table 1 below shows a comparison between the output characteristics according to the present invention and the output characteristics according to the prior art.

[0032]

[Table 1]

As can be seen from Table 1, in the present invention, high torque is generated at the same size as the conventional system, and when the same torque is generated as in the conventional system, the size and thickness can be reduced.

When a pattern coil formed by plating, etching, or the like is used as the coil 19 of the present embodiment, the thickness can be further reduced. Further, when using a pattern coil, a plurality of layers having the coil pole of the present invention may be stacked.

[0035]

As described above, since the number of coil poles is increased by one or two more than the number of poles of the magnet, the same size as that of the conventional type has a higher torque of three.
A phase-driven DC motor can be realized, and a smaller and thinner three-phase driven DC motor can be realized when a motor having the same torque as the conventional one is used.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a sectional structure of a three-phase drive DC motor according to one embodiment of the present invention.

FIG. 2 is a plan view showing an example of a magnetized configuration of the rotor magnet of FIG.

FIG. 3 is a plan view showing a configuration of a flat coil in the case of eight poles to nine coil poles according to one embodiment of the present invention.

FIG. 4 is a graph showing a back electromotive force pattern obtained by the coil according to the embodiment of the present invention shown in FIG. 3;

FIG. 5 is shown for comparison with one embodiment of the present invention;
It is a top view which shows the structure of the flat coil in case of 8 poles-6 coil poles of a conventional example.

6 is a graph showing a back electromotive force output pattern obtained by the conventional coil of FIG. 5;

FIG. 7 is a plan view showing another example of the magnetized configuration of the rotor magnet of FIG. 1;

FIG. 8 is a plan view showing the configuration of a flat coil in the case of 10 poles to 12 coil poles according to another embodiment of the present invention.

9 is a graph showing a back electromotive force pattern obtained by the coil of another embodiment of the present invention shown in FIG. 8;

FIG. 10 is a plan view showing a configuration of a flat coil according to an embodiment of the present invention in a configuration in which in-phase coil poles are not adjacent to each other.

FIG. 11 is a plan view showing a configuration of a flat coil in a case of 14 poles to 15 coil poles according to another embodiment of the present invention.

FIG. 12 is a plan view illustrating a configuration of a flat coil in a case of 16 poles to 18 coil poles according to another embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 11 rotor magnet 12 rotor plate 13 sleeve 14 rotating shaft 15 housing 16 bearing 17 pivot receiver 18 opposed yoke 19 flat coil 1S magnetic pole of S pole 1N magnetic pole of N pole A, B, C, 1A, 1B, 1C, 3A, 3B , 3C input terminals a to r, 2a to 2b, 4a to 4i coil pole

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H02K 29/00 H02K 3/04 H02K 21/24

Claims (2)

(57) [Claims] 1. A ring-shaped magnet having 2p (where p is an integer of 4 or more) magnetic poles on a plane, and 3m (where m is an integer of 3 or more) spirals facing the magnet. And a flat coil in which spiral unit coil poles are arranged in a plane, and a combination of the number of poles of the magnet 2p and the number of spiral unit coil poles 3m is 2p = 2 × (3k + 1)
And 3m = 3 × (2k + 1) or 2p = 2 × (3k +
2) and 3m = 3 × (2k + 2) (where k is an integer of 1 or more). 2. The three-phase drive DC motor according to claim 1, wherein m unit coil poles of the same phase are arranged adjacent to each other in the spiral unit coil poles.