JP2005237175A - Motor and electric vehicle including the motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor with a permanent magnet capable of increasing an output by enhancing rotating magnetic fields generated by the permanent magnet. <P>SOLUTION: This motor is constructed by combining a coil formed of a superconducting wire with a permanent magnet of a rotor of a rotating magnetic field type motor or a permanent magnet of a stator of the rotating magnetic field type motor to enhance the rotating magnetic field generated in the stator by feeding power to an armature coil of the rotor of the rotating magnetic field type motor or the coil of the superconducting wire. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a motor used for a moving body such as an electric vehicle, and in particular, to generate a strong magnetic field exceeding the limit of a rotating magnetic field generated by a permanent magnet when a large power is required so that high output can be achieved. To do.

In recent years, various developments have been made on motors for electric vehicles. In the permanent magnet type motor, the magnetic field generated by the permanent magnet is constant. Therefore, in order to increase the maximum output (torque), the electromagnetic force (F) is F = B (magnetic field) × I (current) × L (armature Since the product of the magnetic field and the current is proportional to the torque, the current supplied to the armature coil must be increased. For example, when 10 times higher output is required, 10 times of current needs to flow. For this reason, it is necessary to increase the capacity of the power source and to provide a circuit having a capacity capable of withstanding a large current at the maximum output (torque).
However, automobiles do not continuously use the maximum output, do not require a large current during normal driving, waste a large-capacity power supply and large current circuit, and increase the size and weight of the power supply and circuit. There is a problem to do.

  Conventionally, as a motor device for an electric vehicle, Japanese Patent Laid-Open No. 6-6907 (Patent Document 1) is provided with a first armature coil and a second armature coil on the rotor side of the motor, and superconductivity on the stator side. A field coil consisting of a body is provided, and an alternating current is passed through the two armature coils to form a magnetic field, while a direct current is passed through the field coil to form a magnetic field, which is rotated by the interaction of these magnetic fields. A superconducting motor device that rotates a child is provided.

However, in the superconducting motor device, since the rotor is rotated only depending on the rotating magnetic field generated by the power supply to the armature coil and the field coil, the armature is used when the rotating magnetic field is increased to obtain a high output. It is necessary to pass a large current through the coil and the field coil. Therefore, it is necessary to form a large capacity and large current circuit of the power source, and the above-described problem cannot be solved.
JP-A-6-6907

  The present invention has been made in view of the above problems, and has improved a permanent magnet type motor, utilizes a rotating magnetic field generated by the permanent magnet, and has a strength exceeding the characteristic limit of the permanent magnet without increasing the power supply capacity. An object of the present invention is to provide a motor that can generate a rotating magnetic field and increase output.

  In order to solve the above problems, the present invention combines a permanent magnet of a rotor of a rotating field type motor or a permanent magnet of a stator of a rotating armature type motor with a coil formed of a superconducting wire. A motor characterized in that a rotating magnetic field generated in the stator is enhanced by feeding power to the armature coil of the stator or the armature coil of the rotor of the rotary armature type motor and the coil of the superconducting wire. Is provided.

  As described above, the present invention is a composite motor in which a superconducting wire coil is attached to a permanent magnet motor. As the permanent magnet type motor, as shown in FIG. 4 (A), a rotor 1 is provided with a permanent magnet 2 and an armature coil is accommodated in a slot 3a of the stator 3; As shown in FIG. 4B, there is a rotary armature type motor B in which an armature coil is accommodated in a slot 1a on the rotor 1 ′ side and a permanent magnet 2 is provided on the stator 3 ′ side. When current is supplied to the armature coils of these permanent magnet type motors, a rotating magnetic field is generated in the hollow portion of the stator, the rotor is rotated, and the drive shaft connected to the rotor is rotated.

In the present invention, as described above, a coil made of a superconducting wire (hereinafter referred to as a superconducting wire coil) is combined with a permanent magnet disposed on the rotor side or the stator side. The superconducting wire coil made of superconducting material is used because the current density cannot be increased with a normal conductor, and the coil attached to the permanent magnet becomes too large, resulting in an increase in the size of the motor. If a superconducting wire coil is used, the current density can be increased without increasing the coil.
Thus, by supplying power to both the armature coil on the side where the permanent magnet is not disposed and the superconducting wire coil on the permanent magnet side, the rotating magnetic field generated by the permanent magnet can be enhanced and high output can be generated. it can. For example, when the rotating magnetic field generated by feeding the superconducting wire coil is increased by a factor of 3, a high output nearly 10 times can be obtained by simply increasing the amount of current supplied to the armature coil by about a factor of three. Therefore, 10 times higher output can be obtained without increasing the power source capacity 10 times.

  The superconducting wire forming the superconducting wire coil is, for example, a bismuth oxide / strontium / calcium / copper superconducting material, a yttrium oxide / barium / copper superconducting material, a superconducting material based on mercury, or a superconducting material based on thallium. A high-temperature superconducting material made of an oxide such as is used. The high-temperature superconducting material exhibits superconducting characteristics even at a liquid nitrogen temperature of 77 (K). Further, if the temperature of liquid hydrogen is 20 (K), the current is about 10 times larger than that at the temperature of liquid nitrogen. It is for flowing.

  In addition, the high-temperature superconducting material can increase the cooling temperature, and can be used with a large current exceeding Ic (critical current) that allows some heat generation, and can take a current density several hundred times that of a normal conductor. Not difficult. Therefore, the coil can be made smaller, and a high output motor can be obtained without enlarging the entire motor.

  Note that the coil for enhancing the rotating magnetic field attached to the permanent magnet is made of a normal conducting material made of copper or the like instead of the superconducting wire coil made of a superconducting wire when the required maximum output is not so large. A coil may be used.

The motor of the present invention is preferably a rotating field motor in which the armature coil is disposed on the fixed side from the viewpoint of cooling the armature coil.
Therefore, it is set as a rotating field type motor, The rotor is equipped with the permanent magnet and the said superconducting wire coil wound around the outer peripheral surface of the permanent magnet in the direction orthogonal to the NS pole direction.

In the rotating field motor, the stator is cooled by cooling means, and the rotor provided with the superconducting wire coil is cooled by indirect conduction cooling from the stator.
For example, a cooling vessel surrounding the stator is provided as a cooling means for the stator, and the rotor including the superconducting wire coil is cooled by indirect conduction cooling from the stator to be cooled.
Specifically, when the outer periphery of the stator is surrounded by a container through which a refrigerant flows, and the stator and the armature coil attached to the stator are cooled by the refrigerant, the hollow portion of the stator is also cooled to the refrigerant temperature, and the hollow The rotor disposed in the section is also cooled, and the superconducting wire coil attached to the permanent magnet of the rotor is also cooled.
Alternatively, a partition plate formed of a high thermal conductivity material is provided in the space between the stator and the rotor, and a refrigerant is introduced into the outer peripheral space partitioned by the partition plate to directly cool the armature on the stator side. At the same time, the stator-side superconducting wire coil may be indirectly cooled via a partition plate.

Any of the above means is a simple cooling mechanism. A simple indirect cooling mechanism in which such a superconducting wire coil is not directly immersed in the refrigerant can be realized by using a superconducting wire coil in order to continuously operate at the maximum output when the motor of the present invention is a motor for an electric vehicle. This is because it is rare to pass a current through the superconducting wire coil, and it is only necessary to cool the superconducting wire coil for a few seconds that require acceleration. Therefore, there is no need for continuous cooling as immersion cooling required when an electromagnet is formed using a superconducting wire coil, and the indirect conduction cooling is sufficient. Further, since the refrigerant fluid is not brought into contact with the rotor, resistance due to friction between the fluids does not occur.
As the refrigerant, in the case of an electric vehicle, liquid hydrogen, liquid nitrogen, or the like used as a fuel for a power source fuel cell is preferably used.

  Furthermore, it is preferable to form at least a part of the armature coil on the stator side of the rotating field motor from a superconducting wire. As described above, when the armature coil is also a superconducting wire coil, the current density can be increased, so that the armature coil can also be reduced in size and contribute to the reduction in the size of the motor. Needless to say, it is advantageous to use all the armature coils as superconducting wire coils.

  Furthermore, a superconducting wire coil may be provided on the inner peripheral surface on the field side of the stator of the rotating field motor. In this way, when the superconducting wire coil is combined with the armature coil on the stator side, the rotating magnetic field to be generated can be further increased, and the maximum output can be increased.

When a rotary armature type motor is used instead of the rotary field type motor, a superconducting wire coil is wound around a permanent magnet that is attached to the inner peripheral surface of the fixed yoke of the stator with a space in the circumferential direction.
Thus, even in a rotary armature type motor in which a permanent magnet and a superconducting wire coil are attached to the stator side and an armature coil is attached to the rotor side, the rotation generated by combining the permanent magnet and the superconducting wire coil. The magnetic field can be enhanced and high output can be obtained.
As described above, when a superconducting wire coil is provided on the stator side, as described above, a partition plate made of a high thermal conductivity material is disposed in the space between the stator and the rotor, and the refrigerant is introduced into the outer peripheral space. Then, the superconducting wire coil can be directly cooled by the refrigerant, and a larger current can be passed through the superconducting wire coil for a longer time than the rotating field motor that is indirect cooling, and the duration of high output can be prolonged. .

The armature coil made of a normal conducting material and the coil made of the superconducting wire are fed when a high output is required, and only the armature coil is fed at a normal output.
For example, when the motor of the present invention is a motor for an electric vehicle, during normal running, an electric current is supplied only to the armature coil to generate a rotating magnetic field in the hollow portion of the stator, thereby rotating the rotor. The driving force for normal driving of an electric vehicle is obtained. On the other hand, when high output is required, such as during acceleration, if power is supplied to the superconducting wire coil attached to the permanent magnet together with the armature coil, the rotating magnetic field generated by the permanent magnet is enhanced and high output can be obtained. .

  As described above, the motor of the present invention is a composite motor in which a superconducting wire coil is combined with a permanent magnet, and when high output is required, the superconducting wire coil is fed to enhance the rotating magnetic field to obtain high output. Therefore, it is suitably used as a motor for an electric vehicle that requires a high output instantaneously during acceleration.

As is clear from the above description, in the motor of the present invention, the permanent magnet type motor is improved, and a composite motor in which the superconducting wire coil is combined with the permanent magnet is used, without increasing the power supply capacity. High output can be obtained.
Therefore, it can be suitably used as a motor that requires a high output instantaneously or in a short time and does not require a high output in normal times. In addition, since the motor does not increase the power supply capacity and does not increase in size, the cost can be reduced, the size can be reduced, and the weight can be reduced.

In particular, when used as a motor for an electric vehicle, during normal electric vehicle traveling, only the armature coil of the normal conducting material is fed to generate a rotating magnetic field in the stator to rotate the rotary drive shaft, and this rotation The driving force of an electric vehicle can be obtained with force. On the other hand, when high output is required, such as during acceleration, the rotating magnetic field can be enhanced by supplying power to the superconducting wire coil, and high output can be obtained.
As described above, the motor of the present invention is suitably used for electric vehicles, but is not limited to electric vehicle motors, and is used as a motor for various applications including motors for electric vehicles such as electric railways and elevators. Can also be suitably used.

An embodiment in which the motor of the present invention is an electric vehicle motor will be described with reference to the drawings.
1 and 2 show a first embodiment of a motor for an electric vehicle.
The motor 10 is used as a drive motor for an electric vehicle equipped with a fuel cell that generates electricity by reacting hydrogen and oxygen, and cryogenic (about 20 Kelvin) liquid hydrogen mounted as a hydrogen supply source is used for the motor 10. It is also used as a refrigerant.

  The motor 10 of the first embodiment is based on a rotating field type permanent magnet motor, and is a composite type in which a superconducting wire coil 15 that is a coil made of a superconducting wire is attached to the permanent magnet 40 of the rotor 100. The superconducting wire coil 15 is formed of a bismuth high temperature superconducting wire.

As shown in FIG. 1, a fixed yoke 11 of a stator 200 having an annular cross section has an armature coil made of a copper wire of a normal conducting material in a slot 11a provided in parallel on the inner peripheral surface in the circumferential direction. 13 is accommodated.
The rotor 100 that is rotatably arranged in the hollow portion of the stator 200 is fixed so that the rotation drive shaft 12 passes through the center shaft hole of the permanent magnet 40 and rotates the permanent magnet 40 and the rotation drive shaft 12 together. I have to. Both end surfaces of the permanent magnet 40 in the axial direction are N-pole and S-pole, and the superconducting wire coil 15 made of the high-temperature superconducting material is wound around the outer peripheral surface of the permanent magnet 40 orthogonal to the axial direction. The rotary drive shaft 12 is rotatably supported by bearings 18 in shaft holes drilled in both side walls 11b and 11c of the fixed yoke 11, and one end of the rotary drive shaft 12 protrudes outward to drive the axle (see FIG. (Not shown).

As shown in FIG. 2, power is supplied from an external power supply 25 to the armature coil 13 on the stator 200 side and the superconducting wire coil 15 on the rotor 100 side. The superconducting wire coil 15 is provided with non-contact power feeding means 26 that feeds the space between the stator 200 and the superconducting wire coil 15 by electromagnetic induction. The non-contact power supply means 26 includes an induction power transmission unit 27 attached to the stator 200 and an induction power reception unit 28 attached to the superconducting wire coil 15 via the exchanger 29. The induction power transmission unit 27 includes The electric wire 24 connected to the power source 25 is connected.
Since the current received by the inductive power receiving unit 28 is an alternating current, the exchanger 29 using a silicon carbide (SiC) semiconductor element is interposed between the inductive power receiving unit 28 and the superconducting wire coil 15, The alternating current is converted into direct current and power is supplied to the superconducting wire coil 15.
The armature coil 13 of the stator 200 is connected to the power supply 25 via the electric wire 23 inserted through the opening of the side wall 11b of the stator 200.

  The motor 10 is cooled by connecting a refrigerant flow path 19 to a refrigerant supply means 20 connected to a tank (not shown) for storing liquid hydrogen, and covering the outer surface of the stator 200 with the refrigerant flow path 19. The refrigerant passage 17a in the jacket 17 is recirculated. The stator 200 is cooled to an extremely low temperature of about 20 Kelvin by the liquid hydrogen flowing back through the refrigerant passage 17a, and the inside of the hollow portion 22 surrounded by the stator 200 is also extremely low temperature. Therefore, the stator 200 is located in the hollow portion 22. The superconducting wire coil 15 of the rotor 100 is also sufficiently cooled.

  As shown in FIGS. 3A and 3B, the cooling mechanism of the motor 10 has high heat such as copper, silver, diamond, aluminum (aluminum nitride, etc.) in the space between the rotor 100 and the stator 200. It is good also as a structure which provides the partition plate 16 formed from the electroconductive material, and introduce | transduces a refrigerant | coolant into the outer peripheral side space 22a partitioned off by this partition plate 16. FIG. With this configuration, the armature coil 13 of the stator 200 may be directly cooled by the refrigerant, and the superconducting wire coil 15 on the rotor 100 side may be indirectly cooled.

Next, the operation of the motor 10 will be described. First, in a normal time, an alternating current is supplied to the armature coil 13 from the power supply 25 of the fuel cell using liquid hydrogen as a fuel via the electric wire 23. A rotating magnetic field is generated in the stator 11 due to a phase shift of the current supplied to the armature coil 13, and the rotating magnet 12 is rotated by the rotating magnet 12 by the rotating magnetic field. The torque of the rotary drive shaft 12 is transmitted to the drive transmission means 21 to drive the wheels to run.
On the other hand, when high output is required, such as during acceleration, power is supplied from the power source 25 to the superconducting wire coil 15 via the electric wire 24, the non-contact power supply means 26 and the converter 29. Thereby, the superconducting wire coil 15 becomes an electromagnet, the rotating magnetic field generated by the permanent magnet 40 is enhanced, and the rotational force of the rotor 100 can be increased without increasing the current supplied to the armature coil 13. It becomes an output and rotates the wheel at high speed.
The current supplied to the armature coil may be a direct current. In this case, the current is sequentially supplied to the armature coil in the circumferential direction to generate a rotating magnetic field to rotate the rotary drive shaft.

  With the above configuration, during normal electric vehicle traveling, current is passed only through the armature coil 13 fixed to the stator 11 to generate a rotating magnetic field in the stator 11 to rotate the permanent magnet 40, and this rotational force. The driving force of an electric vehicle is obtained, but when high output is required, an electric current is also passed through the high-temperature superconducting wire coil 15 fixed to the rotary drive shaft 12 to strengthen the magnetic field, so that the armature coil The output from the superconducting motor device 10 can be increased without increasing the current of the current.

In the first embodiment, the armature coil 13 fixed to the stator 200 is a normal conducting coil. However, at least a part of the armature coils, preferably all the armature coils may be formed of a superconducting material. Good. Thus, if both the armature coil of the stator 200 and the coil attached to the permanent magnet of the rotor 100 are superconducting wire coils, the current density of the coil can be increased, so that the coil can be reduced in size and higher output can be obtained. be able to.

FIG. 4 shows a motor of a second embodiment of the present invention that is a rotary armature type. A permanent magnet 40 ′ having an arc shape is fixed to the inner peripheral surface of the stator yoke 11 ′ of the stator 200 ′ of the motor 10 ′ with an interval of 90 ° in the circumferential direction. As shown in FIG. 4B, a superconducting wire coil 15 ′ made of a high-temperature superconducting material is wound around these permanent magnets 40 ′ so as to surround the permanent magnet 40 ′. In the figure, the permanent magnet 40A ′ arranged vertically has an S pole on the outer circumference and the N pole on the inner circumference, and the permanent magnet 40B ′ arranged on the left and right has an N pole on the outer circumference and an S pole on the inner circumference.
On the other hand, a circumferentially parallel slot 30a is provided on the outer peripheral surface of the rotor yoke 30 that passes through the rotational drive shaft 12 'of the rotor 100', and an armature coil 13 'made of a normal conducting material is accommodated in each slot 30a. It is fixed.

  In this rotary armature type motor 10 ′, since the superconducting wire coil 15 ′ is arranged on the inner peripheral surface on the stator 200 ′ side, a space between the stator 200 ′ and the rotor 100 ′ is formed as shown in the figure. Partitioning is performed by a partition plate 16 ′ made of a high heat transfer material, a refrigerant is circulated in the outer space 22 ′, and the superconducting wire coil 15 ′ is directly cooled by the refrigerant. The armature coil 13 ′ made of normal conducting material on the rotor 200 ′ side is indirectly cooled.

The superconducting wire coil 15 ′ on the stator 200 ′ side is directly connected to an electric wire connected to a power source via an exchanger for converting alternating current into direct current. On the other hand, the armature coil 13 'on the rotor 100' side is supplied with power from a power source by the same non-contact power supply means (not shown) as in the first embodiment.

Even in a rotating armature type motor having the above-described configuration, in a normal state, a current is applied only to the armature coil 13 ′ of the normal conducting material to generate a rotating magnetic field in the stator 200 ′ to rotate the rotor 100 ′, The driving force during normal running is obtained with this rotational force. When high output is required, such as during acceleration, the current to the armature coil 13 'is increased by applying a current to the superconducting wire coil 15' attached to the stator 200 'to increase the magnetic field. The output from the motor 10 'can be made high without any problems.
Further, since the superconducting wire coil 15 'is arranged in the outer peripheral space 22' so that it can be directly cooled by the refrigerant, the superconducting wire coil 15 'can be efficiently cooled, and a high output is obtained continuously for a long time. be able to.
In addition, since another structure and an effect are the same as that of 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In the second embodiment, the number of permanent magnets attached to the stator side is four. However, the number may be two at the opposing position, and the number of permanent magnets is not limited. If a superconducting wire coil is attached to these permanent magnets. Good.

  The composite motor in which the superconducting wire coil is combined with the permanent magnet of the present invention is suitably used as a motor for a moving body that is temporarily required to have a high output, particularly as a motor serving as a drive source for an electric vehicle. .

It is sectional drawing which shows the motor of 1st Embodiment of this invention. It is sectional drawing of the motor apparatus provided with the motor of 1st Embodiment. (A) (B) is drawing which shows the modification of the cooling mechanism of 1st Embodiment. (A) is sectional drawing which shows the motor of 2nd Embodiment of this invention, (B) is drawing which shows the state which attached the superconducting wire coil to the permanent magnet. (A) (B) is drawing which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Motor 11 Stator yoke 12 Rotation drive shaft 13 Armature coil 15 Superconducting wire coil 25 Power supply 40 Permanent magnet 100 Rotor 200 Stator

Claims (9)

  A permanent magnet of a rotor of a rotating field type motor or a permanent magnet of a stator of a rotating armature type motor is combined with a coil formed of a superconducting wire, and the armature coil or rotating armature of the stator of the rotating field type motor is combined. A motor having a configuration in which a rotating magnetic field generated in a stator is increased by feeding power to an armature coil of a rotor and a coil of a superconducting wire.   2. The motor according to claim 1, wherein the rotor is a rotating field motor, and the rotor is provided with a permanent magnet and the superconducting wire coil wound around the outer peripheral surface of the permanent magnet in the direction orthogonal to the NS pole direction.   The motor according to claim 2, wherein the stator is cooled by a cooling means, and the rotor including the superconducting wire coil is cooled by indirect conduction cooling from the stator.   The motor according to claim 2 or 3, wherein at least a part of the armature coil on the stator side is formed of a superconducting wire.   The motor according to any one of claims 2 to 4, wherein a coil formed of a superconducting wire is attached to an inner peripheral surface on a field side of a stator of a rotary field motor.   The motor according to claim 1, wherein the motor is a rotary armature type motor, and a coil made of a superconducting wire is wound around a permanent magnet arranged on the inner peripheral surface of the fixed yoke with a space in the circumferential direction.   The said armature coil and the coil which consists of the said superconducting wire are electrically fed when a high output is required, and it is set as the structure supplied only to the said armature coil at the time of a normal output. Motor.   The motor according to any one of claims 1 to 7, wherein the superconducting wire is a high temperature superconducting wire.   An electric mobile body comprising the motor according to any one of claims 1 to 8.

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