JP3294051B2 - Multi-axis 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 multi-shaft electric motor capable of rotating a plurality of shafts in synchronism, and in particular, to synchronizing two shafts such as a two-shaft gear pump, a two-shaft screw pump, a roots blower and a screw compressor. The present invention relates to a multi-axis electric motor suitable for a rotating machine that needs to be driven in reverse.

[0002]

2. Description of the Related Art Induction motors and DC motors are known as motors used as power sources for pumps and the like. These motors generally have only one rotating shaft. FIG. 15 is a cross-sectional view showing a two-axis rotating machine such as a roots blower driven by an electric motor having only one rotating shaft. The two-axis rotating machine includes a pair of rotors 32 and 33 installed in parallel in a housing 31 and a pair of gears 34 and 35 fixed to shafts 32a and 33a of the rotors 32 and 33 and meshing with each other. ing. The drive shaft 35a of the electric motor 35 is connected to the shaft 32a of one rotor 32.

In the two-axis rotating machine, an electric motor 35
The rotor 32 is rotationally driven by the
The rotation is transmitted to the other rotor 33 via the wheels 4 and 35 so that the two axes are simultaneously inverted and driven.

Japanese Patent Laid-Open Publication No. 4-178143 discloses a two-axis drive motor for synchronously reversing two axes. In this electric motor, as shown in FIGS. 16 and 17, two rotors 41 and 42 having permanent magnets provided in a housing 40 are provided so that the permanent magnets of the rotors come into contact with or approach each other. Two rotors 41, 42
Is a stator 4 in which an armature 43 is provided around an elliptical inner peripheral surface.
4 are supported in parallel. Two rotors 41, 42
Constitutes a magnetic coupling in which the different magnetic pole surfaces of the permanent magnets of the rotors 41 and 42 are opposed to each other in the non-arranged portions of the tooth portions formed opposite to each other.

[0005]

However, FIG.
In the conventional two-axis rotating machine shown in (1), since timing gears such as gears 34 and 35 are required for synchronously reversing the pair of rotors, there is a problem in terms of miniaturization and noise reduction.

In the conventional two-shaft drive motor shown in FIGS. 16 and 17, two rotors 41 and 42 are contacted and supported in parallel, or are supported by providing a gap.
Attraction between the two rotors 41 and 42 is exerted by a magnetic coupling action. In order to suppress excessive eccentric loads on the bearings 45 and 46 generated due to the radial imbalance and obtain stable rotation at high speed,
It is necessary to apply a constant magnetic attraction force opposite to the magnetic attraction force between the two rotors 41, 42, that is, in the opposite direction to cancel the attraction force. However, since the armature 43 provided on the outer periphery forms a rotating magnetic field for driving the rotors 41 and 42, it is difficult to generate such a constant magnetic attraction. Further, when the two rotors 41 and 42 are brought into contact with each other, the problem of the suction force as described above is solved, but friction and noise due to the contact become problems.

The present invention has been made in view of the problems of the prior art, and solves the problem of radial unbalance load due to the magnetic coupling of two rotors.
It is an object of the present invention to provide a two-axis motor capable of stably inverting two rotors at high speed in a synchronized manner. Another object of the present invention is, more generally, to provide a multi-axis motor capable of rotating a plurality of shafts synchronously at high speed and stably.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a plurality of rotors having permanent magnets arranged in parallel, and has a magnetic pole tooth and a magnetic pole tooth all around the outer circumference of each rotor. Dress
A plurality of armatures composed of attached coils are disposed, and permanent magnets provided on adjacent rotors are provided with a plurality of different magnetic poles such that the permanent magnets can be magnetically coupled to each other via the armature and reversible. It name pairs, when driving said adjacent rotor
Then, energize so that the armature at the symmetrical position becomes a different magnetic pole.
Magnetic coupling between the different magnetic poles of the armature at the symmetrical position.
It is characterized by having it be made to be able to do . Or In one embodiment of the present invention was, by dividing the armature core provided with a gap as each phase of the armature blocks the path other than the path for coupling the different magnetic poles of symmetric positions of adjacent rotors I have. Further, in one embodiment of the present invention, a magnetic coupling bar made of a magnetic material dedicated to the magnetic coupling action is bridged between different magnetic poles of adjacent rotors. The magnetic coupling bar is inserted between slots which are symmetrical between the two armatures. Furthermore, the present invention
In the aspect, the number of magnetic poles of the permanent magnets of the adjacent rotors is made different, and the rotors are synchronously inverted at a rotational speed ratio according to the magnetic pole number ratio.

[0009]

In the multi-shaft electric motor configured as described above, the magnetic flux generated from each rotor forms a closed magnetic circuit between the rotors, and acts as a magnetic coupling on each rotor. The circuit closes through a common armature core and balances between each armature and rotor.
Therefore, a rotational force that reverses the rotors in synchronization is obtained, and an excessive eccentric load is not applied to the rotor bearing, and a stable rotational force at high speed is obtained.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a multi-axis motor according to the present invention will be described below with reference to FIGS. FIG. 1 is a sectional view showing a two-axis motor as an example of the multi-axis motor of the present invention, and FIG. 2 is a sectional view taken along line II-II of FIG. As shown in FIG. 1, a pair of rotors 2A and 2B are housed in the motor frame 1. Each rotor 2A, 2B is rotatably supported by bearings 5, 5 near both ends. The two rotors 2A, 2B are circumferentially provided so that magnetic flux is generated in the radial direction at equal intervals symmetrically about 2n poles (n is the number of poles) permanent magnets 2a, 2b. In this embodiment, each rotor 2A, 2B has n = 2, and S, N,
S and N four-pole permanent magnets are provided around each rotor.

A plurality of armatures 3a ₁ are provided on the outer peripheral side of the rotors 2A, 2B so as to surround the entire outer periphery of each rotor 2A, 2B.
~3a _6, 3b ₁ ~3b ₆ is disposed. The pitch between adjacent armatures is set to 60 °. Each armature 3
_{a 1 ~3a 6, 3b 1 ~3b} 6 is pole teeth U～Z formed armature core Ac, and U1～Z1, magnetic pole teeth U～Z, U
1 to Z1. The magnetic pole teeth U to Z and U1 to Z1 are formed at equal circumferential intervals, and the magnetic pole teeth U to Z and U1 to Z1 are provided with both rotors 2.
The coils 4a and 4b are respectively mounted so as to have symmetric and opposite magnetic poles on the center plane C of the axes A and 2B, and the coil 4b is wound in the opposite direction to the coil 4a.

Next, the operation of the multi-shaft electric motor configured as described above will be described. FIG. 3 is an explanatory diagram illustrating the operation of the electric motor. In FIG. 3, only the rotor and the armature are shown to simplify the illustration. Armature coils 4a, 4b
When a current is supplied to the armature, a spatially moving magnetic field is formed in the armature to rotate the rotors 2A and 2B in reverse. That is, in the state of FIG. 3A, the magnetic pole teeth U and X of the armature have N
When the poles and the magnetic pole teeth V and Y are energized so that the S pole is formed, and the magnetic pole teeth U1 and X1 of the armature are energized so that the S pole and the magnetic pole teeth V1 and Y1 are simultaneously formed with the N pole, the rotor 2A, 2B is rotationally driven in the opposite direction as indicated by the arrow.

Similarly, in FIG. 3B, the magnetic pole teeth V, Y
, An N pole is formed on the magnetic pole teeth W and Z, and a magnetic pole tooth V
1 and Y1, an N pole is formed, and magnetic pole teeth W1, Z1 are formed with S poles. Further, as shown in FIG.
N poles are formed on the poles and the magnetic pole teeth W and Z, and the magnetic pole teeth X1 and U are formed.
When an electric current is applied so as to simultaneously form an N-pole at 1 and an S-pole at the magnetic pole teeth W1 and Z1 at the same time, the rotors 2A and 2B are rotationally driven in continuous directions indicated by arrows by continuous rotational force.

Each of the permanent magnets 2 of the rotors 2A and 2B
The magnetic field generated by a and 2b is configured such that a magnetic path is formed between the rotors 2A and 2B and closed by an armature. Therefore, the pair of rotors 2A and 2B have a magnetic coupling action on the different magnetic pole surfaces, and rotate to the opposite sides in synchronization with each other.

FIG. 4 is a time chart of the energization pattern to the coils during the operation shown in FIG. 3, and shows the direct current supplied to the coils 4a of the magnetic pole teeth U to Z and the coils 4b of the magnetic pole teeth U1 to Z1. It is a figure showing an energization pattern. Each of the magnetic pole teeth U to Z and the magnetic pole teeth U1 to Z1 includes FIG.
(B), a spatial moving magnetic field (rotating magnetic field) is generated so as to be magnetized as shown in FIG.
B rotate synchronously in opposite directions as described above. The energizing circuit for energizing the DC of the pattern shown in FIG.
Although illustration is omitted, it can be constituted by an existing electric element such as a semiconductor element.

FIG. 5 is a circuit diagram showing an energized state of the coil during the operation shown in FIG. FIG. 5A shows the energized state of the coil during the operation of FIG. 3A, and FIG.
FIG. 5C shows the energized state of the coil during the operation of FIG.
Indicates the energized state of the coil during the operation of FIG.

In the first embodiment shown in FIGS. 1 to 5 described above, a pair of rotors 2A and 2B around which permanent magnets 2a and 2b are provided are arranged in parallel, and are arranged around the entire outer circumference of each rotor. arranged a plurality of armatures _{3a 1 ~3a 6, 3b 1 ~3b} 6, the permanent magnets 2a, 2b, the rotor 2A, a plurality of pairs of different magnetic poles so as to be magnetically coupled via the armature between 2B To achieve synchronous reversal by the magnetic coupling action, and to provide an even and balanced load in the radial direction without applying excessive eccentric load to each bearing. Thus, it is possible to provide a motor that can perform synchronous inversion driving and have a long life.

Further, according to the present embodiment, the adjacent rotor 2
When the permanent magnets 2a and 2b are magnetically coupled between A and 2B, the magnetic coupling can be performed between a plurality of pairs of different magnetic poles, so that the magnetic coupling area can be increased and the air gap length can be uniform. A large synchronizing force without pulsation can be obtained. Further, according to the present embodiment, when driving the pair of rotors 2A and 2B, current is supplied so that the armatures at symmetrical positions have different magnetic poles. Can further enhance the magnetic coupling effect.

FIG. 6 is a diagram showing a second embodiment of the present invention. In this embodiment, the armatures of the respective phases are divided so as to couple different magnetic poles at symmetric positions of adjacent rotors. That is, the permanent magnets 2a of the rotor 2A and the permanent magnets 2b of the rotor 2B are arranged so that magnetic coupling is formed on different magnetic pole surfaces at symmetrical positions.
Armature _{3a 1 ~3a 6, 3b 1 ~3b} 6 is disposed on the entire circumference of the B. Each armature _{3a 1 ~3a 6, 3b 1 ~3b} 6
The magnetic pole teeth U~ formed armature core Ac ₁ to Ac ₆
Z, U1 to Z1 and coils 4a, 4b mounted on the magnetic pole teeth U to Z, U1 to Z1. These armatures are U-U1, V-V1, W-W1, XX, Y
-Y1, Z-Z1 Thus, the structure is connected only by each phase.

With the above configuration, each rotor 2
Magnetic coupling can be performed on different magnetic pole surfaces at the symmetrical positions of A and 2B. In particular, it is possible to enhance the magnetic coupling effect when no current is supplied. Also in the present embodiment, when power is supplied in the same manner as in FIGS. 3 to 5, the rotors 2A and 2B rotate synchronously and reversely.

FIG. 7 shows a modification of the embodiment shown in FIG.
This embodiment is similar to the embodiment shown in FIG.
In order to clarify the configuration of the magnetic paths of A and 2B, the magnetic pole teeth a to
1 is an example in which the magnetic pole teeth opposing the magnetic pole teeth a1 to l1 are connected to each other. FIG. 8 is also a modification of the embodiment shown in FIG. This is an example in which the armature is configured substantially the same as the example shown in FIG. In the embodiment shown in FIGS. 7 and 8, if the magnetic coupling action is obtained without mounting the coils 4a and 4b, a pair of rotors 2 supported in parallel are provided.
It is possible to obtain a parallel magnetic coupling device that enables synchronous inversion of A and 2B.

FIG. 9 is a diagram showing a third embodiment of the present invention. In this embodiment, the armature core is divided by providing a gap so as to block magnetic paths other than the magnetic path coupling the different magnetic poles at symmetric positions of the adjacent rotors. In the present embodiment, the rotor 2A having the permanent magnets 2a and 2b provided therearound,
The outer peripheral portion of 2B, each rotor 2A, a plurality of armatures 3a ₁ so as to surround the entire periphery of 2B ~3a _6, 3b ₁ ~3b ₆
Are arranged. The pitch between adjacent armatures is 60 °
Is set to Each armature 3a ₁ ~3a _6, 3b ₁ ~
3b ₆ are magnetic pole teeth U~ formed armature core Ac ₁
Z, and U1～Z1 formed armature core Ac _2, the magnetic pole teeth U～Z, coils 4a mounted on U1～Z1, is composed of a 4b. The magnetic pole teeth U to Z, U1 to Z1 are formed at equal circumferential intervals, and the magnetic pole teeth U to Z, U1 to Z1 are formed with magnetic poles symmetrical and opposite to each other on the center plane C of the axis of both rotors 2A, 2B. The coils 4a and 4b are respectively mounted so that the coil 4b is wound in the opposite direction to the coil 4a.

The magnetic pole teeth of the armature core Ac ₁ are cutouts 5 a, 5 a provided perpendicularly to a line connecting the axis of the rotor 2 a and the axis of the rotor 2 b and extending vertically along a line passing through the axis of the rotor 2 a. , Y, 2 aliquoted Z and the magnetic pole teeth V, X, the W, magnetic pole teeth of the armature core Ac ₂ is likewise and passing through the axis of the rotor 2b at right angles to the line connecting the axial center of the rotor 2a and the rotor 2b Magnetic pole teeth U1, Y1,
It is equally divided into Z1 and magnetic pole teeth V1, X1, and W1.

The other structure is the same as that of the embodiment shown in FIG. Also in the present embodiment, when power is supplied in the same manner as in FIGS. 3 to 5, the rotors 2A and 2B rotate synchronously and reversely. Further, as described above, the notch 5a and the notch 5b are provided, so that the magnetic pole tooth X is located between the magnetic pole teeth V-V1.
As a result, the coupling action between -X1 is enhanced, and they are always rotated in opposite directions synchronously.

FIG. 10 is a diagram showing a fourth embodiment of the present invention. In this embodiment, a magnetic coupling bar made of a magnetic material is bridged between different magnetic poles of each rotor. That is, as shown in FIG. 10A, a plurality of U-shaped magnetic coupling bars 7a, 7b, 7c made of a magnetic material are formed, and FIG.
As shown in FIG. 0 (b), the rotors 2A and 2B are inserted into slots S of the armature cores Ac arranged around the entire circumference so that a closed magnetic path is formed on the different magnetic pole surfaces of the rotors 2A and 2B. At this time, the armature core Ac and the U-shaped magnetic coupling bar 7
A predetermined gap is provided between a, 7b, and 7c. The magnetic flux passing through each slot S is magnetically coupled at different magnetic pole surfaces of the rotors 2A and 2B, and the rotors 2A and 2B are synchronously inverted. According to this embodiment, the magnetic coupling bar 7a,
7b and 7c can enhance the magnetic coupling effect when no current is supplied. Also, the magnetic coupling bar 7a,
The magnetic coupling bars 7a, 7b, 7c are easy to insert because the magnetic coupling bars 7b, 7c are inserted between the slots S that are symmetrical between the two armatures. That is,
The magnetic coupling bars 7a, 7b, 7c can be easily attached to each other without magnetic interference.

FIG. 11 is a view showing a fifth embodiment of the present invention. In this embodiment, the permanent magnets of a pair of adjacent rotors have different numbers of magnetic poles, and the pair of rotors are synchronously inverted at a rotational speed ratio according to the magnetic pole number ratio. That is, as shown in FIG. 11, a four-pole permanent magnet 2a of S, N, S, N is provided around the rotor 2A, and S, N, S, N, S,
An N six-pole permanent magnet 2b is provided around the periphery. Rotor 2A
And the permanent magnets 2b of the rotor 2B have the same circumferential length, and the ratio of the number of magnetic poles is 2: 3.

[0027] outer periphery of the rotor. 2A, the armature 3a ₁ to 3 A ₆ so as to surround the entire outer periphery of the rotor 2A are arranged. Also on the outer peripheral side of the rotor 2B, the armature 3b ₁ ~3b ₉ so as to surround the entire outer periphery of the rotor 2B is provided. In the rotor 2A, the pitch between adjacent armatures is set to 60 °, and in the rotor 2B, the pitch between adjacent armatures is set to 40 °.

The armatures 3a _{1 to} 3a ₆ and 3b _{1 to} 3b ₉
The magnetic pole teeth U~ formed armature core Ac ₁ to Ac ₇
Z, U1 to Z1, X2 to Z2 and magnetic pole teeth U to Z, U1 to
And coils 4a and 4b mounted on Z1, X2 and Z2.

FIG. 12 is a diagram showing an energization pattern of a DC current supplied to each coil 4a of the magnetic pole teeth U to Z and each coil 4b of the magnetic pole teeth U1 to Z1 and X2 to Z2. FIG.
FIG. 3 is a circuit diagram showing the energized state of each coil. FIG.
As shown in FIG. 13, each magnetic pole tooth U
As shown in FIG. 12, a spatial moving magnetic field is generated in the magnetic pole teeth U1 to Z1 and the magnetic pole teeth U1 to Z1 and X2 to Z2, and the rotors 2A and 2B rotate synchronously in opposite directions. In this case, the rotation speed ratio between the rotor 2A and the rotor 2B is 3: 2, which is the rotation speed ratio inversely proportional to the magnetic pole ratio.

The multi-shaft electric motor of this embodiment is suitable for a case where each pump rotor is driven at a predetermined rotation speed ratio by a screw compressor or the like.

FIG. 14 is a diagram showing a sixth embodiment of the present invention. This embodiment is a diagram showing a four-axis motor as another example of the multi-axis motor. In the present embodiment, the rotors 2A, 2B, 2C, 2D adjacent to each other are magnetically coupled and synchronously rotate in opposite directions (in the direction of the arrow). The four-axis electric motor of the present embodiment is applied to, for example, a stirrer or the like, and exhibits excellent effects.

[0032]

As described above, according to the present invention, the reversal of a plurality of shafts can be achieved by the magnetic coupling action, and the respective bearings can be balanced in the radial direction without applying an excessive eccentric load. Since a uniform load is obtained, a plurality of shafts can be driven stably and synchronously at high speed, and a long-life motor can be provided.
Further, according to the present invention, a large magnetic coupling area can be taken, and a uniform air gap length can be obtained over the entire circumference, so that a large pulsation-free synchronizing force can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of a multi-axis electric motor according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is an explanatory diagram illustrating the operation of the multi-axis electric motor shown in FIGS. 1 and 2.

FIG. 4 is a time chart of an energization pattern for a coil during the operation shown in FIG. 3;

FIG. 5 is a circuit diagram showing a state of energizing a coil during the operation shown in FIG. 3;

FIG. 6 is a view showing a second embodiment of the multi-axis electric motor according to the present invention.

FIG. 7 is a modification of the embodiment shown in FIG.

FIG. 8 is a modification of the embodiment shown in FIG.

FIG. 9 is a view showing a third embodiment of the multi-axis electric motor according to the present invention.

FIG. 10 is a view showing a fourth embodiment of the multi-axis electric motor according to the present invention.

FIG. 11 is a view showing a fifth embodiment of the multi-axis electric motor according to the present invention.

12 is a time chart of an energization pattern to each coil in the embodiment shown in FIG.

13 is a circuit diagram showing a state of energizing each coil in the embodiment shown in FIG.

FIG. 14 is a view showing a sixth embodiment of the multi-axis electric motor according to the present invention.

FIG. 15 is a sectional view of a conventional two-axis rotating machine.

FIG. 16 is a sectional view of a conventional two-axis electric motor.

FIG. 17 is a sectional view taken along line XVII-XVII in FIG. 16;

[Explanation of symbols]

1 motor frame 2A, 2B rotor _{3a 1 ~3a 6, 3b 1 ~3b} 6 armature 4a, 4b coils 5a, 5b notch 7a, 7b, 7c magnetic coupling bar Ac, Ac ₁ to Ac ₇ armature core

────────────────────────────────────────────────── ─── Continued from the front page (72) Inventor Yasushi Kube 11-1 Haneda Asahimachi, Ota-ku, Tokyo Ebara Corporation (56) References JP-A-4-178143 (JP, A) Hei 4-156259 (JP, A) JP-A-61-289143 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02K 16/00 H02K 7/00 H02K 7/10

Claims (4)

(57) [Claims] 1. A plurality of rotors having permanent magnets disposed in parallel are arranged, and magnetic pole teeth and magnetic pole teeth are mounted on the entire outer periphery of each rotor.
A plurality of armatures composed of attached coils are disposed, and permanent magnets provided on adjacent rotors are provided with a plurality of different magnetic poles such that the permanent magnets can be magnetically coupled to each other via the armature and reversible. It name pairs, when driving said adjacent rotor
Then, energize so that the armature at the symmetrical position becomes a different magnetic pole.
Magnetic coupling between the different magnetic poles of the armature at the symmetrical position.
Multi-axis motor is characterized in that so as to grayed. 2. A multi-axis motor of claim 1 Symbol mounting, characterized in that adjacent phases of the armature to couple different poles of symmetric position of the rotor is arranged to divide. 3. An armature core is divided by providing a gap so that each phase armature blocks a magnetic path other than a magnetic path coupling a different magnetic pole at a symmetric position of an adjacent rotor. claim 1 or 2 multiaxial motor according. 4. The multi-axis electric motor according to claim 1, wherein the number of magnetic poles of the permanent magnets of the adjacent rotors is made different, and the rotors are synchronously inverted at a rotation speed ratio according to the magnetic pole number ratio.