JP2007060748A - Superconducting multishaft motor and vehicle equipped therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance flux utilization efficiency of a superconducting motor, and to miniaturize the motor while reducing transmission loss. <P>SOLUTION: The superconducting multishaft motor comprises a stator 11 having a superconducting field coil 16 arranged to direct the flux in the axial direction, a first rotor 12 having an armature 22 arranged oppositely to one side of the stator 11 in the axial direction while directing the flux in the axial direction, a second rotor 13 having the armature 25 arranged oppositely to the other side of the stator 11 in the axial direction while directing the flux in the axial direction, a first drive shaft 27 secured to the first rotor 12, and a second drive shaft 28 secured to the second rotor 13 and rotating independently from the first drive shaft 27. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a superconducting multi-axis motor and a vehicle including the superconducting multi-axis motor, and more particularly to a motor having a plurality of drive shafts rotating independently of a motor using a superconducting material.

  In recent years, in order to improve the exhaustion of fossil fuels such as gasoline and the deterioration of the environment due to exhaust gas, the development of electric vehicles and hybrid vehicles that run by driving a motor with electric energy has been promoted. In this case, when a normal conducting motor is used, there is a problem that copper loss occurs due to electrical resistance, resulting in low efficiency and a difficulty in increasing output because of a limit in the energization current. On the other hand, as disclosed in JP-A-6-6907, JP-A-5-276734, etc., if a superconducting motor is employed, copper loss in the superconducting material is eliminated and high efficiency is achieved, while miniaturization and high performance are achieved. It is possible to achieve output. A superconducting motor 1 shown in FIG. 5 has a rotor 2 formed of a superconducting material fixedly fitted to a drive shaft 3 and a stator having a cylindrical cross section with a required gap formed on the outer periphery of the rotor 2. 4 is arranged so that the magnetic flux direction is directed in the radial direction.

  However, although the superconducting motor 1 generates a strong magnetic flux with the superconducting material of the rotor 2, only one side of the N pole and the S pole is effectively used. That is, only the magnetic pole on the outer peripheral side of the rotor 2 that is opposite to the stator 4 is used, and the magnetic pole generated on the inner peripheral side of the rotor 2 does not contribute to the torque, resulting in inefficiency. .

Further, in recent automobiles, there are some cars in which the rotational speeds of the left and right wheels are made different from each other according to the driving situation and the driving stability is improved. In such cars, as shown in FIG. By transmitting the output from the shaft motor 1 to each wheel via the differential gear 5, a rotational difference is generated in each wheel. However, the differential gear 5 is not preferable because it is large in both weight and volume, contrary to the reduction in size and weight of the vehicle, and has a large transmission loss (a loss of about 3 to 7% of the motor output) generated by the gear.
As shown in FIG. 7, a so-called in-wheel motor that incorporates the single-axis motor 1 in each tire wheel of four wheels also appears. However, since the number of motors increases, the vehicle weight and cost increase. Further, since the speed reducer 6 is interposed between the motor 1 and the wheels in order to earn torque, there is also a transmission loss (a loss of about 1 to 3% of the motor output) generated by the gear of the speed reducer 6.
JP-A-6-6907 Japanese Patent Application Laid-Open No. 5-276734

  The present invention has been made in view of the above problems, and it is an object of the present invention to improve the magnetic flux utilization efficiency of a superconducting motor, to reduce the size, and to reduce transmission loss.

In order to solve the above problems, the present invention firstly, a stator having a superconducting field magnet with the magnetic flux direction oriented in the axial direction,
A first rotor having an armature coil disposed opposite to one side in the axial direction of the stator and having a magnetic flux direction in the axial direction;
A second rotor having an armature coil disposed opposite to the other axial direction of the stator and having a magnetic flux direction in the axial direction;
A first drive shaft fixed to the first rotor;
A superconducting multi-axis motor is provided, comprising a second drive shaft fixed to the second rotor and rotating independently of the first drive shaft.

  With the above configuration, the strong magnetic flux generated in the superconducting field magnet generates N and S poles on both sides of the stator, but since the rotor is disposed on both sides of the stator, the magnetic field generated in the superconducting field magnet is not generated. It can be used effectively for torque generation. In addition, since the drive shafts are independently attached to the first rotor and the second rotor, the first drive can be achieved by making the energization to the armature coil of each rotor different to make the rotation speed of each rotor different. The rotational speeds of the shaft and the second drive shaft can be made different independently. The superconducting field body is preferably a superconducting field coil or a superconducting field bulk.

It is preferable that a powder magnetic material is disposed as a magnetic core in the hollow portion of the superconducting field coil and / or the armature coil.
With the above-described configuration, the dust magnetic body is advantageous in that it is easy to mold with a mold and has excellent workability and isotropic magnetic characteristics. In addition, the magnetic powder body has a structure in which the magnetic powder is bonded with an insulating resin, or the magnetic powder covered with a coating is bonded with an insulating resin, so that the individual magnetic powders are insulated with a resin. As compared with the soft magnetic material, eddy current loss is reduced and a magnetic core having excellent magnetic characteristics can be obtained, and the magnetic flux of the coil can be strengthened.

The armature coils of the first rotor and the second rotor are preferably formed of a superconducting material.
That is, by making the armature coil superconductive, a large current can flow, and the number of turns of the armature coil can be greatly reduced. Therefore, since the hollow portion can be formed large in the center of the coil, the magnetic core disposed in the hollow portion can be increased, and the magnetic flux can be strengthened to increase the torque.

Second, the present invention is a vehicle equipped with the superconducting multi-axis motor,
The vehicle is characterized in that the first drive shaft is connected to a first wheel and the second drive shaft is connected to a second wheel.

  With the above configuration, according to the superconducting multi-axis motor, the rotational speeds of the two drive shafts can be controlled independently by a single motor, so different rotation speeds are applied to the first wheel and the second wheel. Can be given. Therefore, it is possible to reduce the size of the motor as a whole rather than driving two wheels with two motors, and it is not necessary to use a differential gear or the like as in the prior art, and it is possible to reduce power transmission loss. Become. In addition, the ability to eliminate the differential gear and the like contributes to a reduction in the size and weight of the vehicle. The first wheel is preferably a right wheel and the second wheel is a left wheel.

Preferably, the first drive shaft is directly connected to the first wheel, and the second drive shaft is directly connected to the second wheel.
In other words, in the case of the conventional in-wheel motor, the torque is improved through the reduction gear, but the torque is increased by superconducting the motor, so the vehicle is driven by the direct drive without the reduction gear. It is possible to improve the power transmission rate as well as reducing the weight and increasing the space.

As apparent from the above description, according to the first invention, since the rotor is arranged on both sides of the stator, both poles of the field generated in the superconducting field body can be effectively used for torque generation. Further, since the pair of rotors are independently attached with the drive shafts, the output rotational speeds of the first drive shaft and the second drive shaft can be made different by changing the rotational speed of each rotor. it can.
In addition, according to the second invention, it is possible to give different rotational speeds to two wheels with one motor while eliminating a power transmission loss due to a differential gear or the like, and to reduce the number of on-vehicle motors and reduce the size and weight of the vehicle. Contribute to the realization.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an axial gap type superconducting multi-axis motor 10 according to the first embodiment, in which a first rotor 12 is opposed to one side of the stator 11 in the axial direction and a second rotor 13 is opposed to the other side. It is arranged. Further, the first drive shaft 27 is fixed to the first rotor 12, and the second drive shaft 28 is fixed to the second rotor 13 on the same axis.

  The stator 11 has a substantially disk shape, and a pair of left and right bearings 18 and 19 are arranged at the center of a support portion 14 made of a non-magnetic material such as a resin fixed to a fixing portion G such as a casing. A plurality of coil mounting holes 14a are provided at equal intervals. An annular heat insulating refrigerant container 15 having a vacuum heat insulating structure is embedded in the coil mounting holes 14a, and a superconducting field coil 16 that is a winding made of a superconducting material is accommodated in the heat insulating refrigerant container 15. That is, by arranging the axis of the superconducting field coil 16 in parallel with the axis of the drive shafts 27 and 28, the magnetic flux direction of the coil 16 is directed in the axial direction. A magnetic core 17 made of a magnetic material is disposed in the hollow portion of the heat insulating refrigerant container 15. In this way, a plurality of superconducting field coils 16 are attached at intervals in the circumferential direction around the axis, and are arranged so that the magnetic flux direction of each superconducting field coil 16 faces the axial direction.

The magnetic core 17 insulates magnetic powder (iron powder, etc.) covered with a magnetic powder powder (iron powder, etc.) covered with a magnetic powder (iron powder, etc.) or heat treated by press bonding with an insulating resin. The magnetic powder body is bonded with resin and heat-treated. A resin such as polyphenylene sulfide or soluble polyimide is preferably used as the resin for binding the dust magnetic material.
As a superconducting material for forming the superconducting field coil 16, a bismuth-based or yttrium-based superconducting material is used. The heat insulating refrigerant container 15 is supplied with a cryogenic refrigerant such as liquid nitrogen from a refrigerant supply unit (not shown). The superconducting field coil 16 is supplied with power from a power supply device (not shown).

  The first rotor 12 and the second rotor 13 have a substantially symmetrical disk shape, and a first drive shaft 27 is fixed to the center of the yoke 21 of the first rotor 12. The first drive extends slightly from the yoke 21. The end of the shaft 27 is fitted in the bearing 18 of the stator 11. On the other hand, the second drive shaft 27 is independently fixed to the center of the yoke 24 of the second rotor 13, and the end of the second drive shaft 28 slightly extending from the yoke 24 is fitted into the bearing 19 of the stator 11. is doing.

  Coil mounting holes 21a and 24a are provided at equal intervals in the circumferential direction on the outer surface side of the yokes 21 and 24 facing the stator 11, and the coil mounting holes 21a and 24a are made of a normal conductive material such as copper. A plurality of armature coils 22 and 25 are embedded. That is, by arranging the axis of the armature coils 22 and 25 in parallel with the axis of the drive shafts 27 and 28, the magnetic flux direction of the coils 22 and 25 is directed in the axial direction. In addition, magnetic cores 23 and 26 made of a magnetic material are disposed in the hollow portions of the armature coils 22 and 25. As described above, the plurality of armature coils 22 and 25 are attached at intervals in the circumferential direction around the axis, and are arranged so that the magnetic flux direction of each armature coil 22 and 25 faces the axial direction. The yokes 21 and 24 and the magnetic cores 23 and 26 are covered with a powder magnetic material obtained by press-bonding magnetic powder (iron powder or the like) with an insulating resin and subjected to heat treatment, or a coating (phosphoric acid compound coating or the like). The magnetic powder (iron powder or the like) is made of a powder magnetic material obtained by bonding with an insulating resin and performing a heat treatment. A resin such as polyphenylene sulfide or soluble polyimide is preferably used as the resin for binding the dust magnetic material.

With the above configuration, by feeding different currents to the armature coil 22 of the first rotor 12 and the armature coil 25 of the second rotor 13, the left and right rotors 12 and 13 are separately and independently provided. It can rotate and can make the rotation speed of the 1st drive shaft 27 and the 2nd drive shaft 28 different.
Further, by arranging the rotors 12 and 13 on both sides of the stator 11, both the strong left and right magnetic poles generated by the superconducting field coil 16 can be effectively used for torque generation. That is, by using the superconducting field coil 16 effectively, the amount of expensive superconducting material used can be suppressed, and cost performance is improved. Instead of the superconducting field coil 16, a known superconducting field bulk may be used.

Next, the vehicle C equipped with the superconducting multi-axis motor 10 will be described.
As shown in FIG. 3, the vehicle C (electric vehicle) is supplied from the battery 30, two inverters 31 and 32 that convert the direct current from the battery 30 into alternating current of a predetermined voltage, and the battery 30 and the inverters 31 and 32. And a superconducting multi-axis motor 10 driven by the generated electric power. The left wheel 33 is directly connected to the first drive shaft 27 of the superconducting multi-axis motor 10, while the right wheel 34 is directly connected to the second drive shaft 28. Note that a direct current is supplied to the superconducting field coil 16 of the stator 11, and an alternating current is supplied to the first rotor 12 and the second rotor 13.

  With the above configuration, there is no need to provide a conventional differential gear or the like between the motor 10 and the wheels 33 and 34, and power transmission loss can be reduced. Further, since the differential gear and the like can be eliminated, the vehicle C can be reduced in size and weight, and an in-vehicle space can be provided. Furthermore, since the gear system can be reduced, noise due to gear friction can be eliminated, which contributes to improvement in the quietness of the vehicle C. In addition, the number of motors mounted on the vehicle can be halved compared to conventional in-wheel motors.

FIG. 4 shows a second embodiment.
The difference from the first embodiment is that the armature coils 41 and 44 of the first rotor 12 'and the second rotor 13' are formed of a superconducting material.
The first rotor 12 ′ and the second rotor 13 ′ are provided with coil mounting holes 21 a and 24 a at equal intervals in the circumferential direction on the outer surface side of the yokes 21 and 24 facing the stator 11. The heat insulating refrigerant containers 40 and 43 having an annular and vacuum heat insulating structure are embedded in the holes 21a and 24a. In addition, magnetic cores 42 and 45 made of a magnetic material are disposed in the hollow portions of the heat insulating refrigerant containers 40 and 43. As described above, the plurality of superconducting armature coils 41 and 44 are attached at intervals in the circumferential direction around the axis, and are arranged so that the magnetic flux direction of each superconducting armature coil 41 and 44 faces the axial direction. The magnetic cores 42 and 45 are press-molded using a powder magnetic material obtained by applying an insulating coating with a resin or the like to a magnetic powder such as iron powder.

  With the above configuration, the armature coils 41 and 44 are also superconducting to allow a large current to flow, so that the number of turns can be greatly reduced and a large space can be formed at the center of the coil. Therefore, the large magnetic cores 42 and 45 can be disposed in the coil hollow portion, and the magnetic flux is strengthened to contribute to the torque increase. In addition, since the stator 11 is the same as that of 1st Embodiment, it attaches | subjects the same code | symbol and abbreviate | omits description.

It is sectional drawing of the superconducting multi-axis motor of 1st Embodiment of this invention. It is a front view of a stator. It is the schematic of the vehicle carrying a superconducting multi-axis motor. It is sectional drawing of the superconducting multi-axis motor of 2nd Embodiment. It is sectional drawing which shows the superconducting motor of a prior art example. It is the schematic of the vehicle of a prior art example. It is the schematic of the vehicle of another prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Superconducting multi-axis motor 11 Stator 12 1st rotor 13 2nd rotor 15 Adiabatic refrigerant container 16 Superconducting field coil 17, 23, 26 Magnetic core 18, 19 Bearing 21, 24 Yoke 22, 25 Armature coil 27 First drive shaft 28 Second drive shaft C vehicle

Claims (6)

A stator having a superconducting field with the magnetic flux direction in the axial direction;
A first rotor having an armature coil disposed opposite to one side in the axial direction of the stator and having a magnetic flux direction in the axial direction;
A second rotor having an armature coil disposed opposite to the other axial direction of the stator and having a magnetic flux direction in the axial direction;
A first drive shaft fixed to the first rotor;
A superconducting multi-axis motor comprising: a second drive shaft fixed to the second rotor and rotating independently of the first drive shaft.   The superconducting multi-axis motor according to claim 1, wherein the superconducting field body is a superconducting field coil or a superconducting field bulk.   The superconducting multi-axis motor according to claim 2, wherein a dust magnetic material is disposed as a magnetic core in a hollow portion of the superconducting field coil and / or the armature coil.   The superconducting multi-axis motor according to any one of claims 1 to 3, wherein the armature coils of the first rotor and the second rotor are formed of a superconducting material. A vehicle equipped with the superconducting multi-axis motor according to any one of claims 1 to 4,
A vehicle having the first drive shaft connected to a first wheel and the second drive shaft connected to a second wheel.   The vehicle according to claim 5, wherein the first drive shaft is directly connected to the first wheel, and the second drive shaft is directly connected to the second wheel.

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