JP2002153036A - Rotary machine and wind power generator using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary machine which can positively utilize heat generated within itself, while preventing thermal demagnetization of an R-T-B magnet, in a rotating machine equipped with an R-T-B magnet. SOLUTION: This is a rotary machine 1 which has a sealed container 12, an R-T-B permanent magnet 14a stored in the container, and a coil which is stored in the sealed container and counterposed to the permanent magnet 14a and performs the conversion between rotational energy and electrical energy, using the permanent magnet 14a and the coil 16a, and this is equipped with a thermoelectric conversion element 19 which converts heat produced by the current flowing in the coil 16a into electrical energy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating machine, and more specifically, to an R-T-
The present invention relates to a rotating machine having a B-based permanent magnet.

[0002]

2. Description of the Related Art At present, a wind power generator is attracting attention as a power generator capable of generating electric power without polluting the environment, and its development is being promoted. As a wind power generator, a permanent magnet type wind power generator that generates electric power using a magnetic field formed by a permanent magnet is known. A permanent magnet type wind power generator does not require power supply to a magnetic field generating coil, unlike an induction power generation type wind power generator. Therefore, it can be used in various places where it is difficult to install a power supply.

Hitherto, a permanent magnet type wind power generator has been used as a small power generator having an output of about 100 W. Ferrite magnets were often used as permanent magnets. However, recently, a wind power generation system in which the output is further improved by using a rare earth magnet in place of a ferrite magnet has been proposed (for example, Japanese Patent Application Laid-Open No. 9-1997).
No. 23374). Since the magnetic force of a rare earth magnet is generally higher than the magnetic force of a ferrite magnet, the use of a rare earth magnet greatly increases the output power (for example, to about 10 times).
It is possible to improve. Among rare earth magnets, R-
TB-based magnets (R is a rare earth element containing Y, T is iron, or a transition metal element in which part of iron is replaced by Co, etc., and B is boron) have particularly high magnetic properties. In addition, research on a high-output wind power generator using an RTB-based magnet has been actively conducted.

While having such high magnetic characteristics, R
The -TB magnet has the property of poor corrosion resistance. For this reason, the RTB-based magnet is usually used after forming a protective film such as Ni plating on the surface thereof. However, as in the case of being used for wind power generators, R-
When the TB magnet is left outdoors (for example, in a location where sea breeze blows), the above-described protective film alone cannot sufficiently protect the magnet. For this reason, when using an RTB magnet in a wind power generator, it is necessary to house the power generation unit in a highly airtight housing (container) and protect the RTB magnet from the surrounding environment. is there.

[0005]

However, when power is generated in the space sealed by the housing as described above, the heat (Joule heat) generated by the current flowing through the coil is likely to be accumulated in the housing. , R
-The temperature of the TB magnet increases. R-T as described above
When the -B magnet is used, the amount of power generation (that is, the amount of current flowing through the coil) is significantly increased as compared with the case where a ferrite magnet is used, so that the heat generation of the coil is considerably large. Thereby, the temperature of the RTB-based magnet also becomes extremely high. Unlike a ferrite magnet, an RTB-based magnet does not recover its magnetic properties and undergoes irreversible heat even if the temperature is lowered to about room temperature after thermal demagnetization at a high temperature. Demagnetization occurs. Therefore, the subsequent power generation is performed in a state where the magnetic properties of the RTB-based magnet are deteriorated. In this case, the power generation efficiency is significantly reduced.

[0006] In order to prevent the magnetic properties from deteriorating due to an increase in temperature, an R-T-B having an improved heat resistance by adding Co is used.
It is also conceivable to use a system magnet. However, even if such a high heat resistant RTB-based magnet is used, for example, about 2
If the temperature is higher than 40 ° C., thermal demagnetization occurs. Therefore, in a generator requiring a high output, thermal demagnetization may not be sufficiently suppressed in some cases. Further, the addition of Co can lower the residual magnetic flux density of the RTB-based magnet and increase the manufacturing cost of the magnet.

In a rotating machine such as a high-speed rotating motor,
2. Description of the Related Art There is known an air-cooling apparatus that uses a blower to cool an RTB-based magnet used as a rotor (or a stator). However, in the wind power generator, it is necessary to house the RTB magnet in a highly airtight space, and it is difficult to cool the RTB magnet by the wind from the blower. is there. Further, such a cooling method requires electric power for operating the blower, and thus, when the wind generator is provided with the blower, the power generation amount obtained as a whole of the wind generator is substantially reduced.

Japanese Patent Application Laid-Open No. Hei 4-185250 describes a technique for lowering the temperature of an RTB-based magnet using a regenerator. If this technique is used, the temperature of the magnet can be reduced to some extent, but it is difficult to adopt it for a wind power generator having a large amount of heat generation. Further, the generated thermal energy cannot be used positively.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and in a rotating machine using an RTB magnet, deterioration of magnetic characteristics is prevented by preventing an increase in the temperature of the magnet. It is another object of the present invention to provide a rotating machine capable of positively utilizing generated heat.

Another object of the present invention is to provide a wind power generator using the above-described rotating machine.

[0011]

According to the present invention, there is provided a rotating machine comprising: a container having airtightness; and an RTB housed in the container.
A permanent magnet and a coil housed in the hermetically sealed container and provided to face the permanent magnet, and using the permanent magnet and the coil, a rotational kinetic energy and an electric energy A rotating machine for performing conversion, comprising: a thermoelectric conversion element that converts heat generated by a current flowing through the coil into electric energy.

In a preferred embodiment, a high-temperature end of the thermoelectric conversion element is in thermal contact with the coil.

[0013] In a preferred embodiment, the apparatus further comprises a shaft to which the coil is fixed, wherein the permanent magnet can rotate around the shaft.

[0014] In a preferred embodiment, the permanent magnet is fixed to the container, and the container can rotate around the shaft.

[0015] In a preferred embodiment, a low temperature end of the thermoelectric conversion element is thermally connected to the shaft.

In one embodiment, the apparatus further includes a power storage device for storing electric energy generated in the thermoelectric conversion element.

In one embodiment, the cooling device further includes a cooling element that cools the coil by using electric energy generated in the thermoelectric conversion element.

[0018] A wind power generator according to the present invention is configured using any of the rotating machines described above.

A power generator according to the present invention includes a housing defining a substantially sealed space, a pair of magnetic field generating means arranged at intervals in the space to form a predetermined magnetic field, and the pair of magnetic fields. A current path forming means sandwiched by the generating means, and a shaft penetrating the pair of magnetic field generating means and the current path forming means, wherein the pair of magnetic field generating means and the current path forming means are relatively positioned around the shaft. A generator that generates electric power by rotating the magnetic field, wherein each of the pair of magnetic field generating means includes a plurality of Rs arranged in a circumferential direction of the shaft.
A thermoelectric conversion element having a -TB system permanent magnet for converting heat generated by a current flowing through the current path forming means into electric energy is connected to the current path forming means.

[0020] In a preferred embodiment, the current path forming means is fixed to the shaft, and the pair of magnetic field generating means is fixed to the housing and can rotate around the shaft.

In a preferred embodiment, the apparatus further comprises a blade connected to the housing, and the blade and the pair of magnetic field generating means rotate relative to the current path forming means when the blade receives wind.

[0022]

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

As shown in FIG. 1, a wind power generator 1 of the present embodiment has a blade 20 made of fiber reinforced plastic (FRP).
And a rudder 30 made of fiber reinforced plastic. The wind power generator 1 is rotatably supported by the pole 3 and can rotate around the pole 3 according to the wind direction. When the wind blows, feather 20
Is turned in the direction of the wind by the rudder 30, so that the wind power can be efficiently used to generate power.

Next, referring to FIG. 2 and FIG.
0 will be described.

The power generation unit 10 has a coil unit 16 sandwiched between a pair of magnet plates (or magnet units) 14 in a substantially closed space surrounded by a housing (or container) 12 formed of resin or the like. It has a different configuration. The power generation unit 10 also has a shaft 18 (see FIG. 3) penetrating through the center of each of the housing 12, the magnet plate 14, and the coil unit 16. One end of the shaft 18 extends outside the power generation unit 10 and is fixed to the main body of the generator 1 by fixing means (not shown). Further, the blades 20 are fixed to the housing 12.

The coil unit 16 is fixed to the shaft 18, while the magnet plate 14 is fixed to the housing 12. The housing 12 includes the bearing 1
3 through the shaft 18 with low resistance. As the housing 12 rotates, the magnet plate 1
4 also rotates around shaft 18.

Each magnet plate 14 has an N pole and an S pole along the circumferential direction.
The poles are constituted by a plurality of (or having a plurality of magnetic poles) RTB-based magnets 14a alternately arranged. As the RTB-based magnet 14a, NEOMAX35EH (trade name, manufactured by Sumitomo Special Metals Co., Ltd.) can be used. In the pair of magnet units 14, the N pole side of one magnet unit 14 is connected to the other magnet unit 1.
4 is disposed so as to face the S pole side. Similarly,
The S pole side of one magnet unit 14 is arranged to face the N pole side of the other magnet unit 14. As a result, the coil 16a sandwiched between the magnet units 14
Is formed. A back yoke 15 made of a soft magnetic material such as iron is provided on the outer surface of each magnet unit 14 (the surface opposite to the surface facing the coil unit 16). A magnetic circuit is formed by the magnet unit 14 and the back yoke 15, and a desired magnetic field can be generated stably.

The coil unit 16 is arranged radially around a shaft 18 and is constituted by a plurality of coils 16a each forming a current path. The plurality of coils 16a are wound in the circumferential direction in the opposite direction for each pole, and are connected in series with one pole skipped.

In the wind power generator 1, the housing 12 rotates around the shaft 18 when the blade 20 receives wind. At the same time, the magnet unit 14 also rotates around the shaft 18. At this time, the magnet unit 14
Move with respect to the coil 16a, and a magnetic field is continuously applied to each of the coils 16a while sequentially reversing the direction. This causes electromagnetic induction, and an alternating current flows through each coil 16a. Coil 1
The current flowing through 6a is taken out of the power generation unit 10 by a harness (not shown) passing through a center hole provided in the shaft 18, for example. The power generated by the generator 1 is, for example, rectified by a diode and stored in a battery (not shown).

The configuration of the power generation unit 10 is not limited to the above-described embodiment, and the R-T-B
As long as power is generated by using the system magnet and the coil provided opposed thereto, various forms can be used. For example, a plurality of RTB-based magnets are arranged along the circumferential direction on the inner peripheral surface of the cylindrical member while alternately reversing the polarity.
A configuration may be adopted in which the magnet is disposed so as to face the -TB magnet and either the RTB magnet or the coil is rotated.

As described above, if the RTB-based magnets and coils are housed in the space sealed by using the housing (or container), even when the generator 1 is installed in a severe environment, , RTB-based magnets and coils can be properly protected from rust and breakage. However, due to this, heat generated by the current flowing through the coil during power generation is likely to be trapped in the housing, so that the magnetic properties of the heat-sensitive RTB-based magnet may be reduced. In such a wind power generator, it is often difficult to use a cooling means such as a blower.

On the other hand, the power generator 10 of the wind power generator 1 of the present embodiment is provided with a thermoelectric conversion element 19 capable of converting heat energy into electric energy as shown in FIGS. ing. The high-temperature end of the thermoelectric conversion element 19 (one of the two types of dissimilar metal contacts constituting the thermoelectric conversion element) is in thermal contact with the coil 16a,
The low temperature end (the other side of the two kinds of dissimilar metal contacts constituting the thermoelectric conversion element) is in thermal contact with the shaft 18. As the thermoelectric conversion element 19, for example, a Si-Ge based thermoelectric conversion element can be used. NaCo
An oxide thermoelectric conversion element formed from a ₂ O ₄ compound, a Ca ₂ Co ₂ O ₅ compound, or the like, or a Bi ₂ Te ₃ thermoelectric conversion element may be used.

When one contact (high-temperature end) of the thermoelectric conversion element 19 is thermally connected to the coil 16a, heat generated by a current flowing through the coil 16 can be extracted as electric energy. If the other contact (low-temperature end) of the thermoelectric conversion element 19 is connected to the shaft 18, thermoelectric conversion can be performed more efficiently. As described above, one end of the shaft 18 extends to the outside of the housing 12, and the temperature of the shaft 18 is substantially equal to the temperature of the outside. Therefore, if the thermoelectric conversion element 19 is connected to the shaft 18, This is because a large temperature difference is given to the conversion element 19.

When the thermal energy generated in the coil 16a is converted into electric energy using the thermoelectric conversion element 19, the temperature of the coil 16a can be reduced. This reduces the heat accumulated in the housing 12, prevents the temperature of the RTB-based magnet 14a provided facing the coil 16a from rising, and reduces the temperature of the RTB-based magnet 14a. Irreversible thermal demagnetization can be prevented. When a thin RTB-based magnet is used as in the present embodiment, the heat-resistant temperature of the magnet tends to be low. Even in such a case, if the thermoelectric conversion element 19 is used, it is possible to prevent the magnetic properties of the RTB-based magnet from deteriorating and to prevent the power generation efficiency from lowering.

The electric energy obtained from the thermoelectric conversion element 19 can be stored in, for example, a battery. The electric energy obtained by the thermoelectric conversion element 19 can be used as the output power of the wind power generator 1 together with the electric energy obtained from the coil unit 16. Similarly to the output power from the coil unit 16, the output power from the thermoelectric conversion element 19 can be extracted to the outside by a harness (not shown) passing through the center hole of the shaft 18. In the present embodiment, since the coil 16a and the shaft 18 are provided as fixing members in the generator 1, it is easy to connect the thermoelectric conversion element 19 to them.

The coil 16a may be cooled by using the electric energy obtained from the thermoelectric conversion element 19. For this purpose, for example, a Peltier element (not shown) may be fixed to the coil 16a, and the output power from the thermoelectric conversion element 19 may be used as the input power of the Peltier element. By doing so, the temperature rise of the coil 16a and the RTB-based magnet can be more reliably prevented.

It should be noted that a heat conductive member having high heat conductivity made of aluminum or the like may be provided so as to be in contact with the entire coil 16a, and this heat conductive member may be connected to the thermoelectric conversion element 19. Thereby, the thermal contact between the coil 16 and the thermoelectric conversion element 19 can be improved.

As described above, in the wind power generator 1, the coil 1
Heat generated by the current flowing through the thermoelectric conversion element 1
It is actively used by converting it to electrical energy by 9. Since it is relatively easy to incorporate the thermoelectric conversion element 19 into a generator, if the thermoelectric conversion element 19 is used,
In a wide range of generators, heat can be effectively used while preventing heat generation of the coil 16a and the RTB-based magnet 14a.

In the above embodiment, the wind power generator has been described as an example, but the present invention can be applied to various generators and motors.

(Example) A power generator 1 as shown in FIGS. 1 to 4 was manufactured and its power generation performance was examined. As an 8-pole magnet provided so as to sandwich both sides of the coil, NEOMAX35EH (trade name, manufactured by Sumitomo Special Metals Co., Ltd.)
0 mm x outside about 60 mm x side about 80 mm).
A Ge-Si based thermoelectric conversion element (about 8 mm x 80 mm x 80 mm) was provided between each coil and the shaft.

Under the condition that 5Ω is connected as the load resistance, the housing and the RTB are rotated at a rotation speed of 600 rpm.
When the system magnet is rotated, a total of 220
An output of W was obtained. At this time, the temperature of the coil reached about 170 ° C. in a thermal equilibrium state. The temperature of the coil was measured by a thermistor provided near the coil.

Thus, a temperature difference of about 150 ° C. was given to the thermoelectric conversion elements provided for each coil, and a total of 56 W of power could be recovered from the thermoelectric conversion elements.

[0043]

According to the rotating machine of the present invention, by using a thermoelectric conversion element for converting heat generated by a current flowing through the coil into electric energy, the coil is cooled, and the heat generated in the closed space in which the heat is easily trapped is reduced. The temperature rise of the TB magnet is suppressed. This prevents irreversible thermal demagnetization of the RTB-based magnet, which has high performance but is weak to heat, and makes it possible to realize a practical high-output wind power generator.
Further, by accumulating or utilizing the generated thermal energy as electric energy, the energy conversion efficiency of the rotating machine can be substantially improved.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an appearance of a wind power generator according to an embodiment of the present invention.

FIG. 2 is an exploded view of a power generation unit of the wind power generator shown in FIG.

FIG. 3 is a sectional view of a power generation unit of the wind power generator shown in FIG.

FIG. 4 is a plan view showing an arrangement of thermoelectric conversion elements in a power generation unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wind power generator 10 Power generation part 12 Housing 13 Bearing 14 Magnet unit 14a RTB-based magnet 15 Back yoke 16 Coil unit 16a Coil 18 Shaft 20 Blade 30 Direction rudder

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) H02N 11/00 H02N 11/00 A (72) Inventor Fumio Sakamoto 2--15 Egawa, Shimamoto-cho, Mishima-gun, Osaka No. 17 Sumitomo Special Metals Co., Ltd. Yamazaki Works F term (reference) 3H078 AA03 AA26 BB11 BB14 CC22 5H607 BB02 CC05 CC07 DD01 DD10 DD16 FF26 5H621 BB07 HH01 JK13 5H622 CA01 CA06 CA10 CA14 CB02 CB03 DD02 PP16 PP19

Claims (11)

[Claims] 1. An airtight container, an RTB-based permanent magnet housed in the container, and a coil housed in the airtight container and provided opposite to the permanent magnet. A rotary machine that converts between rotational kinetic energy and electrical energy using the permanent magnet and the coil, wherein the thermoelectric conversion element converts heat generated by current flowing through the coil into electrical energy. Rotating machine equipped with. 2. The rotating machine according to claim 1, wherein a high-temperature end of the thermoelectric conversion element is in thermal contact with the coil. 3. The rotating machine according to claim 1, further comprising a shaft to which the coil is fixed, wherein the permanent magnet can rotate around the shaft. 4. The rotating machine according to claim 3, wherein the permanent magnet is fixed to the container, and the container can rotate around the shaft. 5. The rotating machine according to claim 3, wherein a low-temperature end of the thermoelectric conversion element is thermally connected to the shaft. 6. The rotating machine according to claim 1, further comprising a power storage device for storing electric energy generated in said thermoelectric conversion element. 7. The rotating machine according to claim 1, further comprising a cooling element that cools the coil using electric energy generated in the thermoelectric conversion element. 8. A wind power generator using the rotating machine according to claim 1. Description: 9. A housing forming a substantially sealed space, a pair of magnetic field generating means arranged at intervals in the space to form a predetermined magnetic field, and sandwiched by the pair of magnetic field generating means A current path forming means; and a shaft penetrating the pair of magnetic field generating means and the current path forming means, wherein the pair of magnetic field generating means and the current path forming means are relatively rotated around the shaft. Wherein each of the pair of magnetic field generating means has an RTB-based permanent magnet having a plurality of magnetic poles, and is generated by a current flowing through the current path forming means. A generator, wherein a thermoelectric conversion element for converting heat into electric energy is connected to the current path forming means. 10. The apparatus according to claim 9, wherein said current path forming means is fixed to said shaft, and said pair of magnetic field generating means is fixed to said housing and can rotate around said shaft. Generator. 11. The apparatus according to claim 10, further comprising a blade connected to said housing, wherein said blade and said pair of magnetic field generating means rotate relative to said current path forming means when said blade receives wind. The described generator.