JPH07110130B2 - AC motor - Google Patents

Abstract

PURPOSE:To get large torque by connecting one group of the coils, which are wound on U-shaped magnetic cores abutting, being dislocated, on both sides of circular magnetic paths assembled in annulation, to AC power sources and the other group to tuning capacitors. CONSTITUTION:A plurality (three pieces in figure) of circular magnets B1, B2 and B3 (outside the figure) are assembled in annulation through magnetic spaces. Severally three U-shaped magnetic cores A11-A13 and A21-A23 abut on both ends of a common annular magnetic path B being dislocated by half the feet dimensions of U-shaped magnetic cores. To the coils N1-N3 wound on the magnetic poles A11-A13 on the primary side are connected three-phase AC power sources e1-e3, and to the coils N1'-N3' wound on the magnetic poles A21-A23 on the secondary side are connected turning capacitors C1-C3. Inside the annular magnetic path B is arranged a rotor R fixed to a shaft G. Hereby, an AC motor of large torque wherein the features of a parametric motor is made the most can be assembled easily.

Description

The present invention relates to an AC electric motor, and more particularly to a new AC electric motor based on an AC electric motor that utilizes parametric oscillation by an orthogonal magnetic core.

[Prior Art] The present inventors proposed an AC electric motor (hereinafter referred to as a parametric motor) using parametric oscillation using a quadrature magnetic core, and in November 1979, the Institute of Electrical Engineers of Japan (Magnetic Application Research Group Material AM・ I have presented at many academic conferences, including 79-57).

The basic structure of this parametric motor is as shown in FIG.

In the figure, the magnetic paths A ₁ and A ₂ composed of U-shaped soft magnets are the primary and secondary magnetic cores, and are composed of a soft magnetic material so that they are spatially located at 90 °. It is transitionally connected to the magnetic path B. The common magnetic path B is a magnetic path for generating a rotating magnetic field and forms a stator together with the A ₁ and A ₂ magnetic cores. D is a rotor. Windings N ₁ and N ₂ are provided on the primary and secondary magnetic cores A ₁ and A ₂ , respectively. The N ₁ winding connects the single-phase AC power source E _1, the N ₂ winding connecting the tuning capacitor C for producing parametric oscillation.

Parametric oscillation is, as is conventionally known, "when a parameter of a system is periodically changed,
This is a phenomenon in which vibration occurs in the system. "

The above-mentioned parametric motor cyclically causes magnetic saturation in the magnetic core and cyclically changes the inductance to generate parametric oscillation.

In the parametric motor shown in FIG. 4, when the switch Sw is closed and the AC input voltage E ₁ is applied to the N ₁ winding, when the E ₁ becomes larger than a certain value, the primary side magnetic core A 1 and the common magnetic path B are cycled. Magnetically saturated. Therefore, the inductance of the N ₂ winding wound around the secondary magnetic core A ₂ coupled to the common magnetic path B changes periodically. As a result, parametric oscillation occurs, and the voltage E _{2 that} is approximately 90 degrees out of phase with the excitation voltage E ₁ is N ₂
Induced by the winding. Explaining in detail the mechanism in which oscillation occurs, when the magnetic flux in the part shared by the primary side magnetic path and the secondary side magnetic path is saturated, the magnetic resistance in this part causes the primary side magnetic flux Φ
₁ , and Φ ₁ is saturated twice in the positive and negative regions, so that the change in magnetic resistance becomes a double frequency with respect to Φ ₁ . Therefore, the inductance of the secondary side circuit changes at a double frequency with respect to the input frequency of the primary side, tunes with the capacitor under certain circuit conditions, and parametric oscillation occurs. From this, the temporal phase difference and the spatial phase difference between the magnetic flux Φ ₁ passing through the A1 magnetic core and the magnetic flux Φ ₂ passing through the A ₂ magnetic path are both 90 °, and the combined magnetic flux in the common magnetic path B is shown in FIG. As shown, a rotating magnetic field results. The rotor D rotates in the rotation direction of this rotating magnetic field and operates as an electric motor.

Regarding this parametric motor, Japanese Patent Laid-Open No. 55-
No. 144769, published and published in US Pat. No. 4,75
Registered as No. 8,753 and No. 4,764,698.

The parametric motor has many features as follows.

(1) The structure is extremely simple, and therefore the manufacturing cost is low.

(2) The stator has no slots. Therefore, magnetic field ripples and other problems due to the existence of slots do not occur.

(3) The excitation winding can be wound like a transformer. This drastically reduces winding costs.

(4) Insert a variable resistor in parallel with the secondary capacitor,
Velocity control can be facilitated by changing this value.

(5) Since the rotating magnetic field is almost circular, the rotation is smooth and the noise is extremely low.

(6) Forward and reverse rotation is easy by adding a small amount of auxiliary winding.

(7) Since parametric oscillation is used, rotation is smooth even if the primary voltage is a square-wave alternating voltage. That is, unlike general AC motors, their efficiency does not decrease significantly even when driven by a square-wave alternating voltage. This is an extremely excellent feature.

(8) Since there is no slot, a small-sized, high-speed rotating electric motor can be easily manufactured by constructing the magnetic field circuit with ferrite or amorphous magnetic material.

(9) Even if the secondary side circuit fails and a short circuit or a circuit occurs, the parametric oscillation is simply stopped and the motor is not burned or other accidents occur.

The inventors of the present invention have also applied to a linear parametric motor (hereinafter referred to as a linear parametric motor) that takes advantage of these characteristics, and have been applied to it. In November 1982, the Japan Society for Applied Magnetics (6th Academic Lecture 15P C-11 ) Etc.

This linear parametric motor has a basic structure shown in FIG. 5 in which the common magnetic path of the above-mentioned parametric motor is cut open.

By the way, the above-mentioned rotary parametric motor is easy to obtain as a relatively small-sized and high-speed rotating electric motor (there is no theoretical limitation). As an attempt to further increase the torque, a multi-pole type (four poles in FIG. 6) parametric motor is shown based on FIG. 4 as shown in FIG. Basically, increasing the number of poles to 6 poles or 8 poles to obtain a larger torque.

[Problems to be solved by the invention] However, since the parametric motor is composed of orthogonal magnetic cores, the magnetic flux in the magnetic core is three-dimensionally distributed, and the behavior becomes more complicated as the number of poles increases, and If the number of poles is increased, the utilization factor of the iron core of the magnetic circuit will decrease, and as the torque does not increase in proportion to the number of poles, or as the number of magnetic poles increases, it becomes difficult to fabricate the primary or secondary side magnetic core. It is not possible to make full use of the characteristics of parametric motors such as. In particular, it is difficult to make a magnetic core by optimizing the flow of magnetic flux with a metal soft magnetic material such as a silicon steel plate.

An object of the present invention is to eliminate such drawbacks and make use of the features of the parametric motors up to now to enable further size increase (larger torque).

[Means for Solving the Problem] According to the present invention, a plurality of arc-shaped common magnetic paths are assembled in an annular shape with a magnetic gap between adjacent magnetic paths, and one end face of the arc-shaped common magnetic path is assembled. Respectively apply a U-shaped primary magnetic core to the other U-shaped secondary magnetic core. Half of the magnetic core leg dimension is displaced in the circumferential direction from the primary side magnetic core and abutted against each other, the primary side magnetic pole and the secondary side magnetic core are provided with primary side and secondary side windings, and the primary side winding has an AC power source. An AC motor characterized in that a tuning (resonance) capacitor is connected to the secondary winding, and a rotor is incorporated inside the common magnetic path.

That is, according to the present invention, the common magnetic path of the unit drive elements of the linear parametric motor, which the present inventors have proposed so far, is transformed from a linear shape to an arc shape, and the linear propulsive force of the linear motor is converted into a rotational torque, It is intended to rotate the rotor.

[Examples] The present invention will be described with reference to Examples.

FIG. 1 shows a magnetic path configuration of a 6-pole parametric motor as an AC electric motor according to an embodiment of the present invention.

B ₁ , B ₂ , and B ₃ are arc-shaped magnetic paths and are made of soft magnetic material. They are arranged in an annular shape as a whole as shown in Fig. 2, and magnetic interference occurs between adjacent arc-shaped common magnetic paths. In order to reduce the number of gaps, a gap is formed during assembly.

A U-shaped primary side magnetic core A ₁₁ is provided on both end faces of the arc-shaped common magnetic path B _{1 1.}
Then, a U-shaped secondary side magnetic core A ₂₁ whose magnetic core legs are displaced by about 1/2 is brought into contact with this A ₁₁ in order to make a time phase difference of 90 degrees. Similarly, the primary magnetic core A ₁₂ and the secondary magnetic core A ₂₂ are in contact with the common magnetic path B ₂ , and A ₁₃ and A ₂₃ are in contact with B ₃ , respectively, to form 6 poles.

FIG. 2 is a diagram showing a cross-sectional state in the common magnetic path. The primary side cores A ₁₁ , A ₂ , and A ₁₃ are formed by winding windings formed by die winding to form the primary side winding, and the secondary side cores A ₂₁ , A ₂₂ , and A ₂₃ are also secondary side windings. In order to oscillate parametrically in the secondary winding, a tuning capacitor that resonates at the frequency of the applied primary power supply is also connected and electrical connection is made.

The common magnetic path B ₁ , the primary magnetic core A ₁₁ , and the orthogonal magnetic core of the secondary magnetic core A ₂₁ are set as one unit, and this unit element is a unit driving element, that is, one linear parametric motor is constituted. ing.

The magnetic cores A ₁₁ and A ₂₁ may be U-shaped magnetic cores of the same size composed of a soft magnetic material having a high saturation magnetic flux velocity, but in order to shift the phase by 90 degrees when abutting on the traffic magnetic path B ₁ , A ₁₁ and A ₁₂ are arranged so that they are offset by 1/2 of the distance between the legs of the magnetic core.

The power source connected to the primary side can be a single-phase AC source or a three-phase AC source. Figure 3 is a connection diagram when a three-phase AC source is connected. The primary windings N ₁ , N ₂ , N ₃ are star connections. It is an example.

In the present invention, for example, when a 6-pole parametric motor is used, three arc-shaped common magnetic paths are used.
The central angle θ of each common magnetic path is geometrically a maximum of 120 degrees, but in order to prevent magnetic interference between adjacent common magnetic paths, the arc angle θ _B of the common magnetic path is 120 degrees. It is better to use a value smaller than 100 degrees and to set it to θ _B 105 degrees when a three-phase AC source is applied. That is, between the common magnetic paths adjacent to each other in the circumferential direction is θ
Smooth rotation can be obtained by providing a non-magnetic gap θg of about 1/8.

The magnetic path of each part used in the present invention may be made of a soft magnetic material, and commercially available silicon steel (Fe-Si based) permalloy (Fe).
A metallic magnetic material such as -Ni type), an amorphous magnetic material, or a ferrite magnetic material may be used, and a material having a higher saturation magnetic flux density (Bs) is preferable, but it does not impose any limitation.

The 6-pole parametric motor has been described above.
It will be understood that the number of unit driving elements described above may be increased to obtain a larger torque. As a matter of course, the number of unit driving elements is also included in the scope of the invention.

Further, when the input source is a three-phase alternating current source, it can be said that the unit driving element is composed of an integral multiple of three.

[Effects of the Invention] The present invention has been described above. However, the characteristics of the parametric motors proposed by the present inventors have been fully utilized, and further, an extremely simple structure or assembly is facilitated to generate a large torque. It can be said that it has become possible to provide AC motors, but the industrial advantages are great.

[Brief description of drawings]

FIG. 1 shows an AC motor 6 according to an embodiment of the present invention.
Fig. 2 is a perspective view showing the magnetic path configuration of a pole parametric motor; Fig. 4 is a perspective view showing the basic configuration of a conventional parametric motor, Fig. 5 is a perspective view showing the basic configuration of a conventional linear parametric motor, and Fig. 6 is a perspective view of a conventional multi-pole parametric motor. Is. A ₁₁ , A ₁₂ , A ₁₃ ...... U-shaped primary magnetic core, A ₂₁ ,, A ₂₂ ,, A ₂₃ ……
U-shaped secondary side magnetic core, B ₁ , B ₂ , B ₃ ... Arc-shaped common magnetic path.

Claims (3)

[Claims] 1. A plurality of arc-shaped common magnetic paths are assembled in an annular shape with a magnetic gap provided between adjacent magnetic paths, and one end face of each of the arc-shaped magnetic paths has a U-shaped primary side magnetic core on the other side. Also U
The letter-shaped secondary side magnetic cores are displaced from the primary side magnetic core in the circumferential direction by a half of the core leg dimension and abutted, respectively, and the primary side magnetic core and the secondary side magnetic core are provided with the primary side and the secondary side windings, An AC motor characterized in that an AC power supply is connected to the primary winding, a tuning (resonance) capacitor is connected to the secondary winding, and a rotor is incorporated inside the common magnetic path. . 2. The AC motor according to claim 1, further comprising a single-phase AC source connected to the primary winding. 3. The AC electric motor according to claim 1, wherein the arcuate common magnetic path is constituted by an integral multiple of 3, and a three-phase AC source is connected to the primary side winding.