JP2021064997A - Three-phase ac generator - Google Patents

Abstract

To provide a three-phase AC generator capable of efficiently generating power by properly generating a flux linkage, an induction electromotive force (voltage) and an induction current (current) and decreasing a loss caused by a cogging torque.SOLUTION: In a stator core 4, twelve teeth 5 are disposed concentrically with a rotor at 30° intervals with respect to a rotation center of a rotor 3, and coils 8 of the same performance are mounted on the teeth 5. The coils 8 are continuously connected to three sets of teeth 5, each set consisting of four teeth, at intervals of three teeth in such a manner that currents of the same phase are generated when magnetic fluxes from magnets 6 of the rotor 3 are received. Regarding the magnets 6 of the rotor 3, twelve or more even-number magnets 6 whose polarities are different are disposed while being adhered alternately at equal intervals with respect to the rotation center of the rotor 3. The magnets are disposed in the fourth teeth 5 in each of the three sets in such a manner that the magnets of the different polarities are alternately opposed.SELECTED DRAWING: Figure 1

Description

The present invention relates to a three-phase alternator and has a rotor (rotor) having a permanent magnet and a steering core (stator) in which a plurality of teeth arranged concentrically with the rotor are arranged. It relates to a three-phase AC generator that generates an AC voltage when the is rotated.

Conventionally, when a coil is moved within the magnetic field lines of a magnet, an electromotive force (voltage) is generated in the coil, and electromagnetic induction in which a current flows in the coil is used to convert the energy of the magnet into electrical energy to generate electricity. Generators are known.

By the way, in the conventional generator, when a cylindrical rotor having a permanent magnet rotates and passes beside a coil of a steering core arranged outside the rotor, an electric current generated in the coil causes the circumference of the coil. A magnetic field line is generated in the coil, and the magnetic field line collides with the magnetic field line emitted from the permanent magnet of the rotor in the opposite direction to generate a repulsive force, or an attractive force is generated in the form of overlapping in the same direction to stop the movement of the rotor. This results in a decrease in power generation efficiency (magnetic resistance), which requires extra external energy to obtain a constant output power for the magnetic resistance, which causes a decrease in the energy efficiency of the generator.

Therefore, conventionally, the development of a generator having good power generation efficiency by reducing or reducing the magnetic resistance to zero or less has been promoted. A generator that cancels out the attractive force of the magnet by shifting the magnet to an even angle from the axis has been presented, and also in Japanese Patent No. 3047180 (Patent Document 2) and Japanese Patent Application Laid-Open No. 2008-187872 (Patent Document 3). Further, Japanese Patent Application Laid-Open No. 2015-339270 (Patent Document 4) presents a generator using a coreless coil, and a generator in which the core of the coil is shorter than the coil in the axial direction.

Further, in Japanese Patent Application Laid-Open No. 2018-108007 (Patent Document 5), a cylindrical rotor attached to a rotating shaft rotatably supported by a housing and the rotor inside the rotor fixed to the housing are described. It has a cylindrical inner stator arranged concentrically with the rotor and a cylindrical outer stator arranged concentrically with the rotor on the outside of the rotor, and the rotor has a plurality of permanents in the rotation direction. The magnets are arranged in a cylindrical shape with alternating magnetic poles, and the inner and outer stators are located on the side facing the rotor and facing the permanent magnets placed on the rotor, respectively. A plurality of coils that generate an AC voltage when the rotor is rotated are arranged side by side, and at least one of the coils arranged on the inner stator and the outer stator is a high inductance coil. A generator with reduced magnetic resistance, which is a feature, has been proposed.

Patent Document 1: Japanese Patent No. 4524110 Patent Document 2: Japanese Patent No. 3047180 Japanese Patent Document 3: Japanese Patent Application Laid-Open No. 2008-187872 Patent Document 4: Japanese Patent Application Laid-Open No. 2015-339270 Patent Document 5: Japanese Patent Application Laid-Open No. Gazette

However, in the generator described in Patent Document 1, it is necessary to arrange a large number, for example, at least 4 or 8 generators in parallel in the axial direction, and in order to install such a generator, it is necessary to arrange the generators in the axial direction. Not only does it require a lot of space, but it is also economically burdensome. Further, in the generators described in Patent Documents 2 and 3, the magnetic reluctance can be made zero, but on the other hand, since the magnetic flux leaks greatly, the magnetic flux that efficiently traverses the coil is reduced and the power generation efficiency is lowered. It cannot function as a generator. Further, the invention described in Patent Document 4 has a problem that it is necessary to determine the length of the core in the coil in order to reduce the magnetic reluctance and generate power with good power generation efficiency.

Further, in the invention described in Patent Document 5, 20 magnets and coils are arranged at equal intervals of 18 ° with respect to the center of rotation, so that the three phases are unlikely to have the same voltage. There is a problem.

The present invention has been made in view of these points, and can appropriately generate interlinkage magnetic flux, induced electromotive force (voltage), and induced current (current), and can reduce loss due to cogging torque. The challenge is to provide a three-phase AC generator that can generate electricity efficiently.

In order to achieve the above object, the three-phase AC generator of the first aspect of the present invention faces a rotor in which a plurality of magnets are fixed at equal intervals with respect to the center of rotation and the surface of the magnets. In a three-phase AC generator in which a stator core is arranged, 12 teeth are arranged concentrically with the rotor at intervals of 30 ° with respect to the rotation center of the rotor, and each tooth has a coil having the same performance. Is mounted, and the coils are continuously connected to each of the four teeth in three sets of three so that a current having the same phase is generated when the magnet of the rotor receives the magnetic flux. The rotor magnets are arranged with 12 or more even magnets having different polarities at equal intervals with respect to the center of rotation of the rotor in close contact with each other, and on each of the four teeth of the three sets. Is characterized in that magnets having different polarities are arranged so as to face each other alternately.

According to the three-phase AC generator of the first aspect of the present invention formed in this way, each of the four teeth of the three sets alternately confronts the magnets having different polarities of the rotor, and thus interlinks. The magnetic flux, the induced electromotive force (voltage), and the induced current (current) can be appropriately generated, the loss due to the cogging torque can be reduced, and the power can be generated efficiently.

Further, the three-phase alternator according to the second aspect of the present invention is characterized in that, in the first aspect, the rotor magnets are formed of 12, 24 or 36 magnets.

According to the three-phase alternator of the second aspect of the present invention formed in this way, in addition to the effect of the first aspect, the loss due to the cogging torque increases as the number of magnets of the rotor increases. It can be greatly reduced and power can be generated efficiently.

Further, in the three-phase alternator according to the third aspect of the present invention, in the first or second aspect, one of the rotor and the stator core is arranged radially inside and the other is arranged radially outside or inside and outside. It is characterized by being.

According to the three-phase alternator according to the third aspect of the present invention formed in this way, the arrangement inside and outside the rotor and the stator core can be exchanged according to the design concept.

Further, in the three-phase alternator according to the fourth aspect of the present invention, in any one of the first to third aspects, each tooth of the stator core is formed into a prism having a rectangular cross section in the circumferential direction. A stainless magnetic flux leakage prevention covering member for preventing magnetic flux leakage from the outside of the tooth is attached to an end portion facing the surface of the magnet.

According to the three-phase alternator of the first aspect of the present invention formed in this way, the magnetic flux leakage from the outside of the teeth is surely prevented, and the magnetic flux that efficiently traverses the coil is increased. The power generation efficiency can be improved.

According to the present invention, the interlinkage magnetic flux, the induced electromotive force (voltage), and the induced current (current) can be appropriately generated, the loss due to the cogging torque can be reduced, and the power can be efficiently generated. A three-phase AC generator can be provided.

Schematic diagram showing a cross section of one embodiment of the present invention Explanatory drawing which also shows the phase relationship of voltage, current, and interlinkage magnetic flux in the embodiment of FIG. A perspective view showing one tooth of the Stee Ichiyo core Explanatory drawing similar to FIG. 2 of other embodiment of this invention

Hereinafter, embodiments of the three-phase alternator of the present invention will be described with reference to FIGS. 1 to 4.

1 to 3 show one embodiment of the present invention.

The three-phase AC power generation 10 of the present embodiment has a cylindrical rotor 3 attached to a rotating shaft 2 rotatably supported by the housing 1, and the rotor 3 fixed to the housing 1 and inside the rotor 3. It is formed by concentrically arranged cylindrical housing cores 4. The step core 4 is formed by teeth 5 integrally formed with a cylindrical yoke (joint iron) and projecting along the outer peripheral surface, and each tooth 5 has a coil 8 along the outer peripheral surface. Is wrapped around (see Fig. 3).

The rotor 3 has a plurality of permanent magnets 6 arranged in a cylindrical shape in a state in which magnetic poles S and N are alternately different in the rotation direction. Each magnet 6 is magnetized with parallel anisotropy with its polarity oriented in the radial direction.

Here, the rotor 3 and the stator core 4, which are the features of the present invention, will be further described.

In the three-phase AC generator 10, a rotor 3 in which a plurality of magnets 6 are fixed at equal intervals with respect to the center of rotation and a stator core 4 are arranged so as to face the surface of the magnet 6. In the stator core 4, 12 radial teeth 5 are arranged concentrically with the rotor 3 at intervals of 30 ° with respect to the rotation center of the rotor 3, and each tooth 5 is equipped with a coil 8 having the same performance. The coils 8 are continuously connected to each of the four teeth 5 in three sets of three so that a current having the same phase is generated when the magnetic flux from the magnet 6 of the rotor 3 is received. As a result, three-phase alternating current of U phase, V phase, and W phase is generated. In the magnet 6 of the rotor 3, 12 or more even (12 in this embodiment) magnets 6 having different polarities at equal intervals with respect to the rotation center of the rotor 3 are alternately arranged in close contact with each other. At the same time, magnets 6 having different polarities are arranged so as to alternately face each other of the four teeth 5 of the three sets. When the number of teeth 5 is 12, the number of magnets 6 satisfying this condition may be 24 or 36 (see other examples shown in FIG. 4).

Further, as shown in FIG. 3, the tooth 5 is a prism having a rectangular cross section in the circumferential direction and is formed in a plate shape having a short side of about 1 to 3 mm, and has an end portion facing the surface of the magnet 6. A thin plate-shaped magnetic flux leakage prevention covering member 9 made of stainless steel, which is a kind of non-magnetic material for preventing magnetic flux leakage from the outside of the teeth 5, is attached to the tooth 5. Each tooth 5 is covered with a coil 8 having at least 20 turns or more. Each coil 8 is preferably a high inductance coil, but is not particularly limited. The Ste-Ichiyako 4 has a known configuration capable of collecting three-phase alternating current from the output units of the coils (U-phase, V-phase, W-phase) 8 of each tooth 5.

Next, the operation of this embodiment will be described.

At the time of power generation, a constant external force is applied to the rotating shaft 2, and the rotor 3 rotates at a constant speed, for example, in a counterclockwise direction.

In the three-phase AC generator 10 of the present embodiment, the twelve magnets 6 of the rotor 3 are arranged so that the polarities are alternately in close contact with each other, and four magnets of each of the three phases of U phase, V phase, and W phase are arranged. Magnets 6 having different polarities are arranged so as to alternately face each other with respect to the teeth 5. As a result, magnets 6 having different polarities always face each other alternately with respect to the four coils 8 wound around the four teeth 5 of each of the three phases of the U phase, the V phase, and the W phase. The magnetic field generated in the coil 8 always faces the magnetic field of the magnet 6 having different polarities alternately, and the resistance that blocks the rotation of the rotor 3 by the magnetic field becomes extremely small.

The three-phase AC voltage is the same for all three phases.

FIG. 2 shows the relationship between the interlinkage magnetic flux, the induced electromotive force (voltage), and the induced current (current) in the three-phase AC generator 10 of the present embodiment, and shows the U-phase, V-phase, and W-phase of each coil 8. The waveform of each interlinkage magnetic flux is almost the same as that of the sinusoidal wave.

Then, the waveform of the induced electromotive force becomes a phase waveform delayed by about 90 ° with respect to the waveform of the interlinkage magnetic flux. Similarly, the induced current has a phase waveform delayed by 90 ° with respect to the induced electromotive force.

Each waveform is composed of 360 ° in 6 cycles.

As described above, according to the three-phase AC generator 10 of the first embodiment, the four teeth 5 of each of the three sets alternately face the magnets 6 having different polarities of the rotor 3, so that the interlinkage magnetic flux and the induction The electromotive force (voltage) and induced current (current) can be generated appropriately, the loss due to cogging torque can be reduced, and power can be generated efficiently.

Further, the magnetic flux leakage prevention covering member 9 mounted on the teeth 5 can surely prevent the magnetic flux leakage from the outside of the teeth 5 and increase the magnetic flux that efficiently traverses the coil 8 to improve the power generation efficiency. it can.

The three-phase AC voltage is the same for all three phases, and the loss due to cogging torque can be reduced, so that power can be generated efficiently.

Next, the three-phase alternator 10 of another embodiment shown in FIG. 4 will be described.

The present embodiment is different in that the number of permanent magnets 6 provided in the cylindrical rotor 3 is 36, and the other configurations are the same as those in the above embodiment. Therefore, the same reference numerals are given to the same configurations. The explanation will be omitted.

Also in this embodiment, the 36 magnets 6 of the rotor 3 are arranged in close contact with each other in polarity, and are polar with respect to each of the four teeth 5 of the U-phase, V-phase, and W-phase. Magnets 6 having different polarities are arranged so as to face each other alternately. As a result, magnets 6 having different polarities always face each other alternately with respect to the four coils 8 wound around the four teeth 5 of each of the three phases of the U phase, the V phase, and the W phase. The magnetic field generated in the coil 8 always faces the magnetic field of the magnet 6 having different polarities alternately, and the resistance that blocks the rotation of the rotor 3 by the magnetic field becomes extremely small.

FIG. 4 also shows the relationship between the interlinkage magnetic flux, the induced electromotive force (voltage), and the induced current (current) in the three-phase AC generator 10 of the present embodiment, and shows the U-phase, V-phase, and W-phase of each coil 8. The waveform of each interlinkage magnetic flux is almost the same as that of the sinusoidal wave.

As the number of magnets 6 of the rotor 3 increases as in the present embodiment, the number of magnets 6 arranged between the adjacent teeth 5 of each phase increases, and the loss due to cogging torque is further reduced. It is possible to generate electricity efficiently.

Even when the number of magnets 6 of the rotor 3 is 24, the loss due to the cogging torque can be further reduced as compared with the embodiment shown in FIG. 1, and power can be generated efficiently.

The present invention is not limited to the above embodiment, and can be modified as needed.

For example, one of the rotor 3 and the stator core 4 may be arranged radially inside and the other may be arranged radially outside or inside and outside.

1 Housing 2 Rotating shaft 3 Rotor 4 Stator core 5 Teeth 6 Permanent magnet 8 Coil 9 Magnetic flux leakage prevention cover member 10 Three-phase alternator

Claims (4)

In a rotor in which a plurality of magnets are fixed at equal intervals with respect to the center of rotation, and a three-phase alternator in which a stator core is arranged so as to face the surface of the magnets.
In the stator core, twelve teeth are arranged concentrically with the rotor at intervals of 30 ° with respect to the rotation center of the rotor, and coils having the same performance are mounted on each tooth, and three sets of every three teeth are mounted. The coils are continuously connected to each of the four teeth so that a current having the same phase is generated when the magnetic flux from the magnet of the rotor is received.
The rotor magnets are arranged with 12 or more even magnets having different polarities at equal intervals with respect to the center of rotation of the rotor in close contact with each other, and on each of the four teeth of the three sets. Is a three-phase AC generator characterized in that magnets of different polarities are arranged so as to face each other alternately. The three-phase alternator according to claim 1, wherein the rotor magnet is formed of 12, 24 or 36 magnets. The three-phase alternating current generator according to claim 1 or 2, wherein one of the rotor and the stator core is arranged radially inside and the other is arranged radially outside or inside and outside. Each tooth of the stator core is formed into a prism having a rectangular cross section in the circumferential direction, and a stainless steel magnetic flux leakage prevention cover that prevents magnetic flux leakage from the outside of the tooth at an end facing the surface of the magnet. The three-phase AC generator according to any one of claims 1 to 3, wherein the member is mounted.

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