JP2019216531A - Cylindrical permanent magnet generator - Google Patents

Abstract

To provide a cylindrical permanent magnet generator capable of generating stable and large direct-current with low ripple of voltage and current by minimizing cogging and ripple.SOLUTION: A cylindrical permanent magnet generator comprises: a stator provided with an outer cylinder fixed to a base, a plurality of air core coils arranged on an inner surface of the outer cylinder in the circumferential direction, and an outer yoke; and a rotor provided with a central shaft being concentric with the outer cylinder and axially supported in a rotatable manner by a bearing arranged on the base, an inner cylinder penetrated by the central shaft and fixed, a plurality of magnets each magnetized on an outer circumferential surface of the inner cylinder so that the direction of a magnetic pole lies along the diametrial direction of the cylinder and mutually faces the opposite to its adjacent magnet, and an inner yoke arranged inside the inner cylinder. The number of the magnets is an even number of 4 or more and the number of the coils is one larger or one smaller than the number of the magnets.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cylindrical permanent magnet generator, and more particularly, to a cylindrical permanent magnet generator in which cogging torque and current pulsation are reduced to increase power generation and power generation efficiency.

  As a generator using a permanent magnet, Patent Document 1 discloses a disk-shaped substrate 7 fixed to a transmission shaft 2 and a donut-shaped substrate provided around the substrate 7 as shown in FIG. A first yoke 8, a plurality of permanent magnets 9 provided on a plane portion of the first yoke 8, a donut-shaped second yoke 10 provided in the apparatus main body to face the permanent magnet 9, A power generating apparatus having a plurality of coils 11 provided on a second yoke and generating an induced voltage in the coils by rotating a permanent magnet to generate power is described.

  However, in this type of generator, the coil cuts the magnetic flux a plurality of times during one rotation of the magnet, so that a rotation obstacle called cogging occurs, the rotation is not performed smoothly, and a large starting torque is required. The problem of doing so was presented in Patent Document 2. As a means for solving this problem, Patent Document 2 discloses, as shown in FIG. 7A, a main shaft 30, a magnetic body 20 fixed to the main shaft and magnetized to eight poles on the outer periphery, and a lower part of the magnetic body. It has the iron plate 10 provided and the coil 50 provided on the iron plate 10, and as shown in FIG. 7b, eight coils are arranged along the circumference on the iron plate, and as shown in FIG. 8c. It discloses a DC power generator in which magnets are magnetized at eight stations and the distance between the magnet and the magnetic body is constant.

  However, in the power generation system disclosed in Patent Literature 2, since eight electrodes and coils are provided on the outer periphery, the sizes of the electrodes and coils are relatively smaller than the size of the generator, and the amount of power generation is reduced. It has been pointed out that a problem of reduction in size has occurred (for example, see Patent Document 3).

  As shown in FIG. 8, Patent Document 3 discloses four air-core coils arranged to face the magnet 15 and arranged around the rotation axis of the shaft 12, as shown in FIG. A generator comprising 16 and yoke 17 has been proposed. However, in the generator described in Patent Literature 3, although the size of the coil was increased, the cogging torque was not reduced because there were only four magnets.

Further, in the permanent magnet generator in which the S pole and the N pole are arranged adjacent to each other, there is also a problem that the amount of power generation becomes 0 at the moment when the coil cuts off the magnetic flux, thereby causing voltage and current pulsations.
Since DC involves difficulties in transforming and rectifying, it has been desired to provide a permanent magnet generator that minimizes cogging and generates stable high voltage and large current DC electricity.

Japanese Patent No. 4152476 JP-A-2002-10573 JP 2017-34836 A

An object of the present invention to solve such a problem is to provide a permanent magnet generator capable of generating a stable direct current with little pulsation of voltage and current by minimizing cogging and pulsation of voltage and current. .
Another object of the present invention is to provide a permanent magnet generator capable of outputting a large current DC without reducing the electrodes and coils even when the number of magnets and coils is increased.
Another object of the present invention is to provide a permanent magnet generator having high power generation efficiency by minimizing cogging and pulsation.

A cylindrical permanent magnet generator according to the present invention for solving such a problem includes a base, a stator having a cylindrical inner surface fixed to the base, and a stator installed coaxially with the inner surface of the stator. A cylindrical permanent magnet generator, comprising: a cylindrical rotor rotated by
The stator is provided with an outer cylinder having a cylindrical inner surface fixed to a base and arranged at equal intervals in the circumferential direction on the inner surface of the outer cylinder. A plurality of air-core coils wound around, and an outer yoke provided in a cylindrical shape to cover the outside of the outer cylinder,
The rotor is fixed to a bearing provided on the base, through a center shaft concentrically and rotatably supported by the outer cylinder, and through the center shaft, and rotatably provided inside the outer cylinder. An inner cylinder and a plurality of magnets arranged circumferentially at equal intervals on the outer peripheral surface of the inner cylinder, and magnetized such that the direction of the magnetic poles is along the diameter direction of the inner cylinder and is opposite to an adjacent magnet. And a cylindrical inner yoke provided inside the inner cylinder and in contact with the plurality of magnets,
The number of magnets is an even number of 4 or more, and the number of coils is one more or one less than the number of magnets.

In the present invention, it is preferable that the number of the coils is one more than the number of the magnets.
Further, the number of the magnets may be eight or more.
Each of the four or more even-numbered magnets is arranged so as to be aligned in the central axis direction of the inner cylinder.

In addition, both ends of the four or more even-numbered magnets can be installed so as to be aligned on two mutually parallel planes having an angle with the cross section of the inner cylinder.
Preferably, the coil further includes an iron core.

  The present invention is further characterized by further comprising a rectifier connected to each of the coils, wiring for connecting an output from each rectifier in series, and an output terminal.

  A rotor provided with x (x is an even number of 4 or more) magnets in which N poles and S poles are alternately arranged, and a stator provided with x + 1 or x-1 coils of the present invention And the permanent magnet generator that rotates relatively in opposition to each other, the number of times of cogging and pulsation of one rotation is (x + 1) times or (x Since the intensity increases by -1) and the intensity decreases to 1 / (x + 1) or 1 / (x-1), it is possible to generate a direct current in which cogging is reduced and voltage and current pulsations are flattened.

  Further, in the cylindrical permanent magnet generator of the present invention, the magnet is arranged outside the cylindrical rotor, and the coil can be installed on the inner surface of the stator having the cylindrical inner surface. Therefore, it is possible to provide a permanent magnet generator having a large power generation amount.

  Further, in the cylindrical permanent magnet generator of the present invention, the magnet and the coil face between the inner yoke provided inside the inner cylinder and the outer yoke provided in a cylindrical shape so as to cover the outside of the outer cylinder. Therefore, a decrease in the magnetic flux density of the lines of magnetic force in the air can be suppressed, and the power generation efficiency can be improved.

  In addition, the cylindrical permanent magnet generator of the present invention provides a low-voltage, large-current output when the distance between the magnet and the coil is short, and the voltage increases and the current decreases as the distance between the magnet and the coil increases. Therefore, the voltage / current ratio of the output of the generator with respect to the input torque can be changed by changing the distance between the magnet and the coil according to the use conditions and purpose.

According to another embodiment of the present invention, both ends of each magnet are provided so as to be arranged on two planes parallel to each other and having an angle with the cross section of the inner cylinder. A further difference occurs in the intensity change and phase of the generated current, and the output current can be further smoothed.
Further, according to still another embodiment of the present invention, the power generation amount can be increased by including the iron core in the coil.

It is a longitudinal section along the central axis of the permanent magnet generator concerning one embodiment of the present invention. FIG. 2 is a cross-sectional view taken along aa line in FIG. 1 and schematically illustrating the configuration of a permanent magnet generator having eight permanent magnets and nine coils according to an embodiment of the present invention. It is. FIG. 3 is a partially cutaway perspective view including a bb cross section of FIG. 2, and is a schematic view illustrating the inside of a stator as an example of a stator having nine coils according to one embodiment of the present invention. 1 is a schematic perspective view schematically illustrating a rotor as an example of a rotor having eight magnets according to an embodiment of the present invention. It is a typical perspective view of the rotor concerning other embodiments of the present invention. It is sectional drawing of the permanent magnet generator of the reference 1. It is a layout diagram of the permanent magnet generator described in Reference 2. It is a layout diagram of the permanent magnet generator described in Reference 3.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. This description is for the purpose of describing the present invention, and does not limit the technical scope of the present invention. The present invention can be variously modified and implemented without departing from the technical scope of the present invention.

FIG. 1 is a longitudinal sectional view along a central axis of a permanent magnet generator according to an embodiment of the present invention, and FIG. 2 is an aa sectional view of FIG. 1 is a cross-sectional view schematically illustrating the configuration of a permanent magnet generator having eight permanent magnets and nine coils according to the present invention.
As shown in FIGS. 1 and 2, the cylindrical permanent magnet generator 1 of the present invention includes a base 26, a stator 12 having an inner surface fixed to the base 26, and a rotatable base 26. A cylindrical rotor 10 fixed to a pivotally supported central shaft 22, disposed so as to have the same central axis as the stator 12, and rotated inside the stator 12. The magnet generator 1 can be housed in the housing 30.

FIG. 3 is a partially cutaway perspective view including a bb cross section of FIG. 2, and is a schematic view illustrating the inside of the stator as an example of a stator having nine coils according to one embodiment of the present invention. It is.
As shown in FIGS. 1 to 3, the stator 12 includes an outer cylinder 13, a plurality of coils 16, and an outer yoke 20, and can be housed in the housing 30.

The outer cylinder 13 fixed to the base 26 only needs to have a cylindrical inner surface, and can be provided so as to be incisable. The shape of the outer peripheral surface is not defined.
It is preferable that a plurality of coils 16 be provided on the inner surface of the outer cylinder 13 at equal intervals in the circumferential direction.

  The plurality of coils 16 preferably have electric wires wound around the diameter direction of the outer cylinder 13 in the same direction. Although the shape of the coil 16 is not particularly limited, it is preferable to cover as large a surface as possible in order to collect a large amount of magnetic flux, and from the viewpoint that the thinner the thickness, the smaller the generator can be. The shape may be such that the inner surface of the outer cylinder 13 is covered with the rectangular coil 16.

The outer yoke 20 may be provided in a cylindrical shape so as to cover the outside of the outer cylinder 13, but may be provided between the coil 16 and the inside of the outer cylinder 13.
The outer yoke 20 is preferably formed of soft iron, but any material other than soft iron can be used as long as it is a member that suppresses a decrease in magnetic flux density in lines of magnetic force in air.

FIG. 4 is a schematic perspective view schematically illustrating a rotor as an example of a rotor having eight magnets according to an embodiment of the present invention.
As shown in FIGS. 1, 2, and 4, the rotor 10 can include a central shaft 22, an inner cylinder 11, a plurality of magnets 14, and an inner yoke 18.

The center shaft 22 is preferably rotatably supported by a bearing 24 fixed to a base 26.
The inner cylinder 11 has a cylindrical outer surface and a smaller diameter than the outer cylinder 13, is provided to face the inner surface of the outer cylinder 13, and the rotation shaft 22 can be inserted and fixed at the center thereof.

A plurality of magnets 14 arranged on the outer peripheral surface of the inner cylinder 11 in parallel with the central axis 22 and at equal intervals in the circumferential direction of the inner cylinder 11 are installed so as to face the coil 16 provided on the outer cylinder 13. can do.
The magnets 14 are preferably magnetized such that the direction of the magnetic poles is along the diametrical direction of the inner cylinder 11 and is opposite to the adjacent magnets 14.

  The magnet 14 may be inserted into a hole (not shown) provided in the inner cylinder 11 and may be provided in contact with a cylindrical inner yoke 18 provided on the inner surface of the inner cylinder 11. The inner yoke 18 is preferably formed of soft iron, but any material other than soft iron can be used as long as it is a member that suppresses a decrease in magnetic flux density in lines of magnetic force in air.

The magnet 14 is preferably a thin rectangle in order to reduce the diameter of the generator, and is preferably thin from the viewpoint that it is preferable to cover a wide surface as much as possible to generate a large amount of magnetic flux. it can.
The material of the magnet 14 is not particularly limited, but is preferably a neodymium magnet or a ferrite magnet from the viewpoint of having a high magnetic force.

As shown in FIG. 1, the permanent magnet generator of the present invention is arranged such that the center of a central shaft 22, the inner cylinder 11 of the rotor 10, and the outer cylinder 13 of the stator 12 are the same. It is characterized by the following.
Specifically, a bearing 24 is provided on an extension of the center line 21 of the outer cylinder 13 of the stator 12 fixed to the base 26, and the center shaft 22 of the rotor 10 is rotatably mounted on the bearing 22. The rotor 10 is rotatably supported inside the stator 12 by the center shaft 22 being rotatably passed through the through hole 23 of the outer cylinder 13 and being fixed to the inner cylinder 11 having a smaller diameter than the outer cylinder 13. It can rotate freely.

By connecting the driving device 28 to the rotating shaft 22 and rotating the rotor 10, the magnet 14 and the coil 16 move relative to each other to generate an induced current and generate electric power.
When the driving device 28 supplies a constant driving energy, when the distance between the magnet 14 and the coil 16 is short, an output of a low voltage and large current is obtained, and the voltage increases as the distance between the magnet 14 and the coil 16 increases. The current decreases. Therefore, the current / voltage ratio can be designed to a desirable value depending on the use conditions and purpose.

In the cylindrical permanent magnet generator 1 of the present invention, since the magnets 14 and the coils 16 are arranged between the inner yoke 18 and the outer yoke 20 so as to oppose each other, a reduction in the magnetic flux density of the lines of magnetic force in the air is suppressed. Therefore, the power generation efficiency can be improved.
In addition, since the magnet can be arranged outside the cylindrical rotor and the coil can be arranged on the inner surface of the stator having the cylindrical inner surface, the area of the magnet and the coil can be increased, and large electric power can be obtained. It can generate electricity.

In the permanent magnet generator 1 of the present invention, four or more even-numbered magnets 14 are arranged at equal intervals along the circumferential direction, and a coil 16 that is one more or one less than the number of magnets 14 is a concentric circle. Since the coils pass over the parts arranged at equal intervals along the circumferential direction, the timing at which each coil cuts off the magnetic flux is different, so that cogging and pulsating flow can be effectively reduced.
The number of the magnetic poles 14 is an even number because the N pole and the S pole are paired, and the number of the coils is an odd number because the number is one more or one less than the number of the magnets 14.

  Since the conventional permanent magnet generator is provided with the same number of coils as the magnet in which the N pole and the S pole are alternately arranged, each coil is rotated while the magnet and the coil make one relative rotation. Since the magnetic flux is cut off at the same time as the number of magnets arranged, cogging causes a rotation obstacle and rotation is not performed smoothly, and a large torque is required for the track, causing a problem of pulsation. .

  In the permanent magnet generator 1 of the present invention, x + 1 or x−1 rotors 10 provided with x (x is an even number of 4 or more) magnets 14 in which N poles and S poles are alternately arranged. Are rotated in opposition to the stator 12 provided with the coils 16, so that the timing at which each coil 16 cuts off the magnetic flux differs for each coil.

That is, when the number of the coils 16 is x + 1, x + 1 types of alternating currents having phases different by 1 / (x + 1) are generated in each coil, so that the number of times of cogging and pulsation increases by (x + 1) times. When the intensity is 1 / (x + 1) and the number of coils 16 is x-1, x-1 types of alternating currents having phases different by 1 / (x-1) are generated in each coil. Therefore, the number of times of cogging and pulsation increases (x-1) times, and the intensity becomes 1 / (x-1).
By connecting a rectifier to each coil and connecting the rectified current in series, a DC with smoothed cogging and pulsation can be obtained.

The number of magnets 14 of the present invention is preferably four or more. If the number of magnets 14 is two or less, cogging and pulsation cannot be effectively reduced. The greater the number of magnets 14 and coils 16, the more effectively cogging and pulsation can be reduced.
More preferably, the number of magnets 14 can be eight or more, and the number of coils 16 can be nine or more.
The present invention does not place an upper limit on the number of magnets and coils, as the more magnets and coils 16 the more cogging and pulsating flow can be effectively reduced.

(Example)
A permanent magnet generator having the basic structure shown in FIGS. 1 to 4, specifically, a structure including eight magnets and nine coils, an inner cylinder having an outer diameter of 70 mm and a length of 150 mm 11, eight odymium neodymium magnets having a length of 120 mm, a width of 25 mm, a thickness of 2 mm, and an adsorption force to an iron plate of 8.8 kg are installed. Nine coils having a width of 25 mm and a thickness of 10 mm were installed to manufacture a cylindrical permanent magnet generator.

A DC brushless motor was connected as the driving device 28, a DC power of 12.0 V, 0.2 A was applied, a full-wave rectifier was connected to each coil, and an output terminal of the sizing device was connected in series.
When a load was connected to the output terminal of the generator and tested, an output of 6.8 V and 0.25 A was obtained. The output current was DC and showed no cogging or pulsation.

  As described above, the preferred embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments, and includes all modifications without departing from the technical scope to which the present invention belongs.

Reference Signs List 1 permanent magnet generator 10 rotor 11 inner cylinder 12 stator 13 outer cylinder 14 magnet 16 coil 18 inner yoke 20 outer yoke 21 center line (inner cylinder, outer cylinder, center axis)
23 Rotary shaft through hole 24 Bearing 26 Support part 28 Drive device 30 Housing

Claims (7)

A cylindrical type including a base, a stator having a cylindrical inner surface fixed to the base, and a cylindrical rotor that is installed coaxially with the inner surface of the stator and is rotated inside the stator. Permanent magnet generator,
The stator is
An outer cylinder having a cylindrical inner surface fixed to the base,
A plurality of air-core coils, which are provided at equal intervals in the circumferential direction on the inner surface of the outer cylinder, and the electric wires are wound in the same direction with the diametric direction of the outer cylinder as an axis,
An outer yoke provided in a cylindrical shape covering the outer side of the outer cylinder,
With
The rotor,
A center shaft which is rotatably supported concentrically with the outer cylinder and rotatably on a bearing provided on the base;
An inner cylinder penetrated and fixed to the center axis, and rotatably provided inside the outer cylinder,
A plurality of magnets arranged at equal intervals in the circumferential direction on the outer peripheral surface of the inner cylinder, the directions of the magnetic poles being along the diametric direction of the inner cylinder, and magnetized so as to be opposite to adjacent magnets. ,
A cylindrical inner yoke provided inside the inner cylinder and in contact with the plurality of magnets;
With
The number of the magnets is an even number of 4 or more, and the number of the coils is one more or one less than the number of the magnets.   2. The cylindrical permanent magnet generator according to claim 1, wherein the number of the coils is one more than the number of the magnets.   The cylindrical permanent magnet generator according to claim 1 or 2, wherein the number of the magnets is eight or more.   4. The cylindrical permanent magnet power generator according to claim 1, wherein each of four or more even-numbered magnets is installed so as to be aligned in a central axis direction of the inner cylinder. 5. Machine.   4. The magnet according to claim 1, wherein four or more even-numbered ends of the magnet are arranged on two mutually parallel planes each having an angle with a cross section of the inner cylinder. The cylindrical permanent magnet generator according to any one of the above.   The cylindrical permanent magnet generator according to any one of claims 1 to 5, wherein the coil further includes an iron core. The cylindrical type according to any one of claims 1 to 6, further comprising: a rectifier connected to each of the coils; a wiring connecting an output from each rectifier in series; and an output terminal. Permanent magnet generator.

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