JP5332869B2 - Rotor and stator - Google Patents

Description

  The present invention relates to a superconducting coil, a superconducting device, a rotor, and a stator.

  Superconductors are also expected as energy-saving technologies because of their extremely low electrical resistance, low energy loss, and high current density. For this reason, electric vehicles driven by superconducting motors are being developed as an application field of superconducting technology.

  Copper wires are used for coils for ordinary electric vehicle motors. However, copper wire generates heat due to electrical resistance. For this reason, the electric current value which can be sent through a copper wire is restrict | limited. Therefore, in the case of a coil using a copper wire, it is difficult to obtain a large torque (rotational force) while maintaining a relatively small size. On the other hand, since the superconductor has an extremely low electric resistance, a large current can flow while keeping the loss to a minimum. For this reason, the superconducting coil can continuously obtain a large torque and can efficiently use the energy of the battery. Therefore, the superconducting coil can contribute to energy saving.

  As described above, since the superconducting coil has a large driving force and can contribute to energy saving, development for application to not only a small passenger car but also a large vehicle such as a bus and a truck is underway. As a superconducting motor device in an electric vehicle, for example, the one disclosed in Patent Document 1 below can be considered.

JP 2005-86913 A

  Generally, in order to supply a refrigerant for cooling a superconducting motor, for example, if a refrigerant pipe or the like is arranged from the outside, a means for keeping the refrigerant pipe is required, so that the cooling equipment becomes large and complicated. Therefore, Patent Document 1 discloses a superconducting motor device for an electric vehicle having a configuration in which a superconducting motor is accommodated in a tank storing liquid and the superconducting motor is cooled by the liquid. In this way, since the superconducting motor is cooled by the liquid (liquid nitrogen or the like) stored in the accommodated tank, it is not necessary to connect a cooling facility from the outside. For this reason, while being able to suppress the enlargement of an apparatus, the efficiency which cools a superconducting motor improves.

  By the way, the superconducting motor has a region where the magnetic field is strong in each of the rotor and the stator constituting the motor. The region where the magnetic field is strong is a region where the magnetic field generated by the superconducting coils in each of the rotor and the stator is concentrated. FIG. 5 is a cross-sectional view of a region where a rotor and a stator of a conventional superconducting motor are formed. In other words, FIG. 5 is a cross-sectional view taken along line VV in FIG.

  A region 1a surrounded by a round dotted line in FIG. 5 showing the motor main body 30 is an outermost region (on the side of the rotor core 13 around which the rotor coil 11 of the rotor existing in the center of FIG. 5 is wound ( The outer peripheral side). In FIG. 5, a region 1b surrounded by a dotted line is the innermost region (center side) in the side portion of the stator core 23 around which the stator coil 21 of the stator existing around the rotor is wound. . These regions tend to increase the strength of the magnetic field when the inventor studied using simulations and the like.

  Here, when a magnetic field is applied to the superconducting coil, the current characteristics of the superconducting coil deteriorate (for example, the critical current value decreases). And in the magnetic field, in particular, the direction crossing the width direction and the long axis direction of the superconducting coil, especially the direction along the thickness direction of the superconducting wire constituting the superconducting coil (more specifically, penetrating the main surface of the superconducting wire) The magnetic field applied to the superconducting coil deteriorates the current characteristics of the superconducting coil and causes a phenomenon such as quenching in the superconducting coil. In the conventional motor main body 30 shown in FIG. 5, the rotor coil 11 and the stator coil 21 are arranged in the areas 1a and 1b. For this reason, since a strong magnetic field is applied to the portions of the rotor coil 11 and the stator coil 21 disposed in the regions 1a and 1b, a phenomenon such as quenching may occur in the rotor coil 11 and the stator coil 21. Increases nature. However, Patent Document 1 neither discloses nor suggests this point, nor mentions any countermeasures against the above problem.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a superconducting coil capable of suppressing deterioration of electrical characteristics and a superconducting device using the superconducting coil. Furthermore, it is providing the rotor and stator which comprise the said superconducting apparatus.

  The superconducting coil according to the present invention is a superconducting coil in which a plurality of racetrack coils are stacked, and the inner diameter of the racetrack coil gradually increases from one end to the other end in the stacking direction. Here, the inner diameter is the width between the inner peripheral side surfaces of the racetrack type coil, and particularly the interval between a pair of long sides facing each other in the racetrack type coil. That is, in other words, the inner diameter refers to the shortest distance between the inner peripheral side surfaces of a pair of opposing linear portions that form a racetrack coil.

  As described above, when the superconducting coil is used in a superconducting device such as a superconducting motor, the electrical characteristics can be deteriorated by the magnetic field in the thickness direction of the superconducting coil, if it is disposed in a relatively strong magnetic field region. There is sex. For this reason, it is preferable that the superconducting coil is not disposed in a region where the magnetic field is strong, but is disposed in a region where the magnetic field is weak.

  Here, when the superconducting coil according to the present invention is applied to a superconducting device such as a superconducting motor, the superconducting coil is arranged so as to be wound around the rotor or stator core constituting the superconducting motor. As described above, a region having a strong magnetic field is formed in the vicinity of one end of the core, such as the outermost region on the side of the rotor core and the innermost region on the side of the stator core. In the superconducting coil according to the present invention, the inner diameters of the plurality of racetrack coils constituting the superconducting coil gradually increase from one end to the other end in the stacking direction as described above. Therefore, the superconducting coil can be installed so that the region where the magnetic field is strong is arranged in the inner peripheral portion on the other end side in the superconducting coil. If it does in this way, a superconducting coil will be arranged so that a field with a strong magnetic field may be avoided. As a result, it is possible to reduce the possibility that the electrical characteristics of the superconducting coil deteriorate due to the influence of a strong magnetic field.

  Further, while the inner diameter of the superconducting coil according to the present invention is increased on the other end side, the inner diameter is relatively decreased on the one end side, so that the number of turns of the racetrack coil on one end side is sufficiently increased. be able to. For this reason, the ratio of the volume of the superconductor with respect to the volume which the outer periphery of a superconducting coil occupies can be improved rather than the case where the internal diameter of a superconducting coil is enlarged uniformly.

  That is, when the size of the superconducting device is constant, if the superconducting coil is not provided in the region where the magnetic field is strong, the space factor that is the volume occupied by the superconducting coil in the superconducting device is reduced. If the space factor is lowered, the strength of the magnetic force generated by the superconducting coil in the superconducting device is lowered, and as a result, the performance of the superconducting device is lowered. Therefore, it is preferable to improve the space factor of the superconducting coil in the superconducting device.

  Therefore, for example, in a region where the magnetic field is strong, the superconducting coil is arranged so that the region where the magnetic field is strong falls within the ring-shaped interior (hollow portion) constituting the racetrack coil. That is, the superconducting coil is disposed so as to surround the outside of the region where the magnetic field is strong. At this time, the superconducting coil is arranged so as to pass through a region outside the strong magnetic field region without passing through the strong magnetic field region. That is, since the superconducting coil passes through a region outside the region where the magnetic field is strong, the inner diameter becomes large. Moreover, it is not necessary to arrange | position about the area | region where a magnetic field is weak so that a superconducting coil may be avoided about the said area | region as mentioned above. For this reason, the inner diameter of the superconducting coil can be made smaller than that of the superconducting coil passing through the outer periphery of the region where the magnetic field is strong. Thus, the inner diameter of the superconducting coil can be changed according to the strength of the magnetic field. Therefore, when the magnetic field gradually increases from one end side to the other end side in the stacking direction, the inner diameter of the stacked racetrack coil gradually increases from one end side to the other end side. preferable.

  If it does in this way, while being able to suppress a race track type coil passing through the field where a magnetic field is strong, it can secure without reducing the space factor of a race track type coil. For this reason, the said superconducting coil can suppress deterioration of the electrical property resulting from a strong magnetic field being applied, and can exhibit sufficient performance in the applied superconducting apparatus.

  In the superconducting coil described above, it is preferable that the number of turns of the plurality of racetrack coils is different between the racetrack coil on the one end side and the racetrack coil on the other end side.

  As described above, when adjusting the inner diameter of the racetrack coil according to the magnitude of the magnetic field, for example, the outer diameters of the laminated racetrack coils are made equal. Here, the outer diameter is the width of the outer periphery of the racetrack shape of the racetrack coil, and refers to the interval between the outer periphery of the linear portions extending in the pair of long sides facing each other.

  At this time, by changing the number of turns in each racetrack type coil, for example, the racetrack type coil having a small number of turns has an increased inner diameter, and the racetrack type coil having a larger number of turns has a smaller inner diameter. Accordingly, the inner diameter of the racetrack coil can be adjusted by adjusting the number of turns. By adjusting the inner diameter of the racetrack coil, as described above, it is possible to suppress deterioration of the electrical characteristics of the superconducting coil.

  In the superconducting coil described above, the number of turns on one end side is preferably larger than the number of turns on the other end side. As described above, when the outer diameter is made equal regardless of the inner diameter of the racetrack coil, the inner diameter can be changed by changing the number of turns. Therefore, when the magnetic field gradually increases from one end side to the other end side in the stacking direction, the inner diameter is reduced by increasing the number of turns on one end side, and the number of turns is decreased on the other end side. The inner diameter can be increased. In this way, the space factor of the coil is improved by the race track type coil having a large number of turns on one end side, and at the same time, the race track type coil having a large inner diameter on the other end side is used to improve the superconducting coil by the influence of the magnetic field. Deterioration of electrical characteristics can be suppressed.

  In the superconducting equipment using the above-described superconducting coil, the deterioration of the electrical characteristics of the superconducting coil due to the influence of the magnetic field is suppressed, and the decrease in the space factor of the superconducting coil is also suppressed. For this reason, a high-performance superconducting device can be realized.

The rotor in the present invention is a rotor using a superconducting coil in which a plurality of racetrack coils are laminated. The inner diameters of the plurality of racetrack coils used in the rotor gradually increase from the center side to the outer periphery side of the rotor. The rotor core extends so as to project radially from the center side of the rotor. There is a gap between the rotor core and the racetrack coil wound around the rotor core on the outer peripheral side.

  As the above-described superconducting device, for example, a motor for an electric vehicle can be cited. As described above, the magnetic field in the outermost region (outer peripheral side) of the rotor constituting the motor becomes stronger at the side of the rotor core around which the racetrack coil is wound. Therefore, the inner diameter of the race track type coil in the outer peripheral region of the rotor having a strong magnetic field is made larger than the inner diameter of the race track type coil in the central region of the rotor so that the race track type coil avoids the region having a strong magnetic field. Arrange to pass. In this way, deterioration of the electrical characteristics of the superconducting coil due to the influence of the magnetic field can be suppressed.

  The plurality of racetrack coils used in the rotor preferably have a greater number of turns on the center side of the rotor than on the outer periphery side of the rotor.

  In order to gradually increase the inner diameter of the racetrack type coil from the center side to the outer side of the rotor, the number of turns of the racetrack type coil in the outer side region of the rotor is changed to the race track in the central side region of the rotor. Use less than the number of turns of the mold coil. In other words, the number of turns on the center side of the rotor is made larger than the number of turns on the outer peripheral side of the rotor. For this purpose, for example, the outer diameter of the laminated racetrack coil is made substantially constant on both the outer peripheral side and the central side, the number of turns on the outer peripheral side of the rotor is reduced, and the number of turns on the central side of the rotor is increased. In this way, the inner diameter of the racetrack coil on the outer periphery side of the rotor is larger than the inner diameter of the racetrack coil on the center side of the rotor.

  Thus, for example, in the region on the outer peripheral side of the rotor, the race track type coil is arranged so that only the outer side in the radial direction of the race track type coil passes through the region outside the strong magnetic field and avoids the strong magnetic field region. . In this way, deterioration of the electrical characteristics of the superconducting coil due to the influence of the magnetic field can be suppressed.

The stator according to the present invention is a stator using a superconducting coil in which a plurality of racetrack coils are laminated. The inner diameters of the plurality of racetrack coils used in the stator gradually increase from the outer peripheral side to the center side of the stator. A stator core extending to project toward the center of the stator; There is a gap between the stator core and the racetrack coil wound around the stator core on the center side.

  The stator which comprises a motor exists in the outer peripheral side rather than a rotor. For this reason, as described above, the magnetic field in the innermost region (center side) becomes stronger in the side portion of the stator core around which the racetrack coil is wound. Therefore, the inner diameter of the racetrack coil in the central region of the stator where the magnetic field is strong is made larger than the inner diameter of the racetrack coil in the outer region of the stator, so that the racetrack coil avoids the region where the magnetic field is strong. Arrange to pass. In this way, deterioration of the electrical characteristics of the superconducting coil due to the influence of the magnetic field can be suppressed.

  The plurality of racetrack coils used in the stator preferably have a greater number of turns on the outer periphery side of the stator than on the center side of the stator.

  The number of turns of the racetrack type coil in the region on the center side of the stator where the magnetic field is strong is made smaller than the number of turns of the racetrack type coil in the region on the outer periphery side of the stator. In other words, the number of turns on the outer peripheral side of the stator is made larger than the number of turns on the center side of the stator. For this purpose, for example, the outer diameter of the racetrack coil to be laminated is made substantially constant on both the outer peripheral side and the central side, the number of turns on the central side of the stator is reduced, and the number of turns on the outer peripheral side of the stator is increased. In this way, the inner diameter of the race track type coil on the center side of the stator becomes larger than the inner diameter of the race track type coil on the outer periphery side of the stator.

  Thus, for example, in the region on the center side of the stator, the race track type coil is arranged so as to pass only the outer side in the radial direction of the race track type coil than the strong magnetic field region, avoiding the strong magnetic field region. . In this way, deterioration of the electrical characteristics of the superconducting coil due to the influence of the magnetic field can be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, while suppressing the deterioration of the electrical property by the influence of the magnetic field in a superconducting coil, the deterioration of the performance in the superconducting apparatus using the said superconducting coil can be suppressed. Furthermore, the performance deterioration in the rotor and the stator which comprise the said superconducting apparatus can also be suppressed.

It is a schematic block diagram of the motor which concerns on each embodiment of this invention. It is a schematic sectional drawing in line segment II-II of FIG. 1 which shows the aspect of the cross section of the motor which concerns on Embodiment 1 of this invention. It is a schematic sectional drawing in line segment III-III of FIG. 1 which shows the aspect of the cross section of the motor which concerns on Embodiment 2 of this invention. It is a graph which shows the relationship between the magnitude | size of the perpendicular magnetic field added to the said superconducting wire when the superconducting wire used for the coil of the motor which concerns on this invention is used at 65K, and the magnitude | size of the critical current of the said superconducting wire. It is a schematic sectional drawing in the segment VV of FIG. 1 which shows the aspect of the cross section of the motor used conventionally.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each embodiment, elements having the same function are denoted by the same reference numerals, and the description thereof will not be repeated unless particularly necessary.

(Embodiment 1)
With reference to FIG. 1 and FIG. 2, the motor 100 according to the first embodiment of the present invention includes a motor main body 30 that includes a rotor 10 that is a rotor and a stator 20 that is disposed around the rotor 10. And an output shaft 18 connected to a load that outputs the rotation of the rotor 10. Since the output shaft 18 rotates, the output shaft 18 is rotatably fixed to the stator 20 by a bearing 35.

  The rotor 10 includes a rotor shaft 16 formed around an outer peripheral surface extending in the long axis direction of the output shaft 18. The rotor 10 extends from the rotor shaft 16 so as to protrude radially from the outer peripheral surface of the rotor shaft 16 radially from a central portion (region where the output shaft 18 is disposed) in a cross section intersecting the output shaft 18. And the rotor coil 11 wound around the rotor core 13. The stator 20 is disposed so as to surround the rotor 10 in a cross section intersecting the output shaft 18 of the rotor shaft 16, and includes a stator coil 21 that generates a magnetic field, and a main body of the stator 20 including the stator coil 21. And a stator core 23 formed.

  As shown in FIG. 1, each rotor coil 11 in the rotor 10 includes a plurality of racetrack coils that are wound (turned) a plurality of times so as to form a racetrack shape so as to cover the longitudinal side surface of each rotor core 13. It is a superconducting coil laminated one by one. The race track type coil constituting each rotor coil 11 is configured as a race track type coil by being pancake-wound. Similarly, each stator coil 21 in the stator 20 is wound a plurality of times so as to cover the region in which the stator core 23 protrudes in the direction in which the rotor 10 is arranged (that is, on the center side of the motor main body 30) as shown in FIG. A superconducting coil in which a plurality of (turned) racetrack coils are stacked. The race track type coil constituting each stator coil 21 is configured as a race track type coil by being pancake-wound. In FIG. 1, the stator core 23, the stator coil 21, the coil cooling container 17, and the like shown in FIG.

  As shown in FIGS. 1 and 2, in the motor 100, four layers of racetrack type coils are laminated on the rotor coil 11, and three layers of racetrack type coils are laminated on the stator coil 21. The plurality of racetrack coils constituting the rotor coil 11 and the stator coil 21 are superconducting coils formed of a superconducting wire. Therefore, in order to cool the racetrack type coil, as shown in FIG. 2, a coil cooling container 17 is disposed around the racetrack type coil. If it says from a different viewpoint, the rotor coil 11 or the stator coil 21 is arrange | positioned inside the coil cooling vessel.

  As shown in FIG. 2, the rotor coil 11 of the motor main body 30 has different inner diameters of the racetrack type coils laminated in four layers. Similarly, the stator coil 21 has different inner diameters of the racetrack type coils laminated in three layers. Note that the outer diameters of the four-layered racetrack type coils of the rotor coil 11 shown in FIG. 2 are substantially equal, and the outer diameters of the three-layered racetrack type coils of the stator coil 21 are also substantially equal.

  In the rotor 10, a high magnetic field region 1 a surrounded by a round dotted line in FIG. 2 exists on the outer peripheral side of the rotor core 13 (the side where the stator 20 is disposed). Similarly, the stator 20 has a high magnetic field region 1b surrounded by a round dotted line in FIG. 2 at the center side of the stator core 23 (the side where the rotor 10 is disposed). As described above, the rotor coil 11 and the stator coil 21 have different inner diameters of the racetrack coils that are stacked in plural. As for the rotor coil 11, since the inner diameter of the racetrack type coil increases toward the outer peripheral side of the rotor 10, the superconducting wire constituting the laminated racetrack type coil does not pass through the high magnetic field region 1a. Is arranged. Similarly, since the inner diameter of the race track type coil increases toward the center side of the stator 20 with respect to the stator coil 21, the superconducting wire constituting the plurality of laminated race track type coils forms the high magnetic field region 1b. It is arranged not to pass.

  In the rotor coil 11, the magnetic field gradually increases from the center side (output shaft 18 side) of the rotor core 13 toward the outer peripheral side (stator 20 side), and the high magnetic field region 1 a exists on the outer peripheral side of the rotor core 13. In the stator coil 21, the high magnetic field region 1 b exists from the outer peripheral side of the stator core 23 to the center side (side on which the rotor 10 is disposed). These regions are regions that are relatively close to both the rotor coil 11 and the stator coil 21.

  If the rotor coil 11 and the stator coil 21 made of a superconducting wire are arranged so as to pass through the high magnetic field region 1a and the high magnetic field region 1b, a magnetic field is applied to the coil in the high magnetic field regions 1a and 1b. Among these, the vertical magnetic field, that is, the magnetic field applied in the direction intersecting the longitudinal direction and the width direction of the superconducting wire constituting the coil (that is, the direction along the thickness direction (height direction)) deteriorates the electrical characteristics of the superconducting coil. (That is, the critical current value is lowered). Therefore, as shown in FIG. 2, it is preferable that the rotor coil 11 and the stator coil 21 are arranged (wound) so as not to pass through the high magnetic field region 1a and the high magnetic field region 1b, respectively. If it does in this way, in rotor coil 11, possibility that an electrical property will deteriorate by a high magnetic field of high magnetic field field 1a is reduced. For this reason, high electrical characteristics can be secured for the rotor coil 11 (that is, a high critical current value can be maintained). Similarly, the possibility that the electrical characteristics of the stator coil 21 deteriorate due to the high magnetic field in the high magnetic field region 1b is also reduced. For this reason, high electrical characteristics can be secured for the stator coil 21.

  However, for example, in order to prevent the superconducting coils from passing through the high magnetic field regions 1a and 1b, for example, if the number of laminations (number of turns) of the race track type coils constituting the rotor coil 11 and the stator coil 21 is simply reduced. As a result, the occupation ratio of the superconducting coil in the motor decreases, and as a result, the strength of the magnetic field due to the superconducting current flowing in the rotor coil 11 and the stator coil 21 decreases. Then, even if a superconducting current having the same magnitude is passed, the magnitude of the generated magnetic field is reduced, and the output of the motor 100 is lowered. For this reason, it is preferable not to decrease the space factor of the race track type coils constituting the rotor coil 11 and the stator coil 21. If the space factor of the race track type coils constituting the rotor coil 11 and the stator coil 21 is not reduced and kept constant, the motor 100 can suppress the deterioration of the electrical characteristics of the superconducting coil.

  In order not to reduce the space factor of the racetrack type coil, it is preferable not to reduce the number of layers of the racetrack type coil. For this reason, as shown in FIG. 2, it is preferable to arrange a racetrack coil so as to surround the high magnetic field region 1a and the high magnetic field region 1b. For example, a racetrack in which a high magnetic field region 1a is present in the stacking direction of the rotor coil 11 (the direction connecting the center side and the outer periphery side in FIG. 2) among the four-layered racetrack type coils constituting the rotor coil 11. When no racetrack type coil is arranged in the two-layer region on the outer peripheral side of the die coil, the space factor of the racetrack type coil of the rotor coil 11 is equivalent to two racetrack type coils. On the other hand, as shown in FIG. 2, the high magnetic field region 1a is present in the stacking direction of the rotor coil 11, and the region of two layers on the outer peripheral side is also avoided so as to avoid the high magnetic field region 1a. A racetrack coil wound around the outside is disposed. By doing so, the space factor of the race track type coil of the rotor coil 11 is equivalent to four layers of the race track type coil. Therefore, by arranging the race track type coil also on the outer peripheral side of the high magnetic field region 1a in the stacking direction, the space factor of the race track type coil is improved, so that sufficient output of the motor can be ensured. it can.

  Therefore, when the high magnetic field region 1a exists in the region on the outer peripheral side of the rotor core 13, as shown in FIG. 2, with respect to the rotor coil 11, the one end (that is, the center side) in the laminating direction of the racetrack coil is It is preferable that the inner diameter of the racetrack coil gradually increases. Similarly, when the high magnetic field region 1b is present in the central region of the stator core 23, the stator coil 21 is directed from one end (ie, the outer peripheral side) to the other end (ie, the central side) in the stacking direction of the racetrack type coil. Thus, it is preferable that the inner diameter of the racetrack coil gradually increases. If it does in this way, the said coil can be wound avoiding the high magnetic field area | region 1a, 1b, ensuring the space factor of the race track type coil in the rotor coil 11 and the stator coil 21. FIG. For this reason, while being able to suppress deterioration of the electrical characteristics of the rotor coil 11 and the stator coil 21, the output of the motor 100 can be improved.

  As described above, the outer diameters of the plurality of racetrack coils stacked in each of the rotor coils 11 are substantially equal. Here, the superconducting wire is wound around the racetrack type coil a plurality of times by pancake winding. Therefore, the rotor coil 11 includes a racetrack coil having a small inner diameter on one end side (center side) in the laminating direction of the racetrack coil and a racetrack having a large inner diameter on the other end side (outer peripheral side) in the laminating direction. The number of turns differs from the type coil.

  For example, as shown in FIG. 2, the racetrack type coil on the center side of the rotor coil 11 has a circumferential direction (direction intersecting the stacking direction) compared to the racetrack type coil on the outer peripheral side of the rotor coil 11. Has a wide width (thickness). The said width | variety respond | corresponds to the number of turns by the pancake winding of the superconducting wire which comprises a racetrack type | mold coil. For this reason, the racetrack coil on the center side with a small inner diameter has a larger number of turns than the racetrack coil on the outer peripheral side with a large inner diameter. Thus, in the superconducting coil, when the outer diameter of each of the plurality of laminated racetrack coils is made substantially equal, the number of turns for pancake winding of the superconducting wire is changed, and the width of the coil in the circumferential direction ( The inner diameter can be changed by changing the (thickness). Specifically, the greater the number of turns of the racetrack coil, the wider the racetrack coil and the smaller the inner diameter. Further, the smaller the number of turns of the racetrack coil, the narrower the width and the larger the inner diameter. In this way, for example, by increasing the inner diameter, the race track coil can be arranged so as not to pass through the high magnetic field region 1a.

  As shown in FIG. 2, the same can be said for the stator coil 21 as in the rotor coil 11 described above. That is, the race track type coil on the outer peripheral side of the stator coil 21 has a wider width in the circumferential direction than the race track type coil on the central side of the stator coil 21. Therefore, the outer race track type coil with a smaller inner diameter has a larger number of turns than the central race track type coil with a larger inner diameter.

  Thus, if the inner diameter is changed by changing the number of turns for each racetrack type coil, for example, than the racetrack type coil arranged in the high magnetic field region 1a, which is arranged in a region other than the high magnetic field region 1a. A racetrack coil with a large number of turns can create a larger magnetic field due to its large space factor. Therefore, the output of the motor 100 can be further improved.

  The superconducting wire used for each racetrack type coil constituting the rotor coil 11 and the stator coil 21 described above may be a thin film superconducting wire having a laminated structure including a superconducting layer, or powder as a superconductor may be used as a tube. It may be a superconducting wire formed by filling a wire and performing wire drawing, sintering, or the like. Moreover, as a material of the superconductor used for the superconducting wire, it is preferable to use an oxide superconducting wire made of an oxide such as Bi (bismuth) or Y (yttrium). Since the oxide superconducting wire can exhibit a function as a superconductor at a higher temperature than the metal superconducting wire, the use of the oxide superconducting wire can simplify the facility for cooling the coil, for example.

  Further, as the superconducting coil constituting the rotor coil 11 and the stator coil 21, for example, a saddle type coil may be used instead of the racetrack type coil described above. Or, for example, the surface of the superconducting wire relative to the surface in the extending direction of the racetrack coil (ie, the surfaces of the stacked racetrack coils facing each other when a plurality of racetrack coils are stacked as the superconducting coil) A racetrack coil in which a superconducting wire is wound so that the (main surface) has a certain inclination angle may be used. If the above coil is used, the superconducting coil can be arranged so that the extending direction of the main surface of the superconducting coil easily follows the direction of the lines of magnetic force in the magnetic field generated by the superconducting coil. The magnitude of the vertical magnetic field can be reduced as compared with the case of using.

  In the motor 100 described above, the racetrack coil has an inner diameter that gradually increases from one end to the other end in the stacking direction with respect to both the rotor 10 and the stator 20. However, depending on the situation, for example, only one of the rotor 10 and the stator 20 is a racetrack type coil having the above-described embodiment, and the other racetrack type coil is, for example, the racetrack type coil shown in FIG. The same may be applied.

(Embodiment 2)
The appearance of the motor 100 in the second embodiment is also substantially the same as that of the motor 100 in the first embodiment described above. Therefore, the schematic configuration diagram showing the appearance here shares the same one as that of FIG. 1 showing the motor 100 in the first embodiment. FIG. 3 shows a cross section of the motor 100 according to the second embodiment at the same location as that of the motor 100 according to the first embodiment. Further, also in the conventional superconducting motor described above, FIG. 5 shows a cross section at the same place as in FIGS. For this reason, the area | region which shows a cross section in FIG. 1 is shown as "II, III, V."

  As shown in FIG. 3 which shows a cross section of the motor 100 of the first embodiment at the same position as that of FIG. 2 with respect to the motor 100 of the second embodiment, the motor 100 of the second embodiment is similar to that of the first embodiment. The motor 100 has a similar aspect in general. However, in the motor 100 of the second embodiment, a plurality of laminated racetrack coils constituting the rotor coil 11 and the stator coil 21 are arranged stepwise on the sectional view. That is, for example, the racetrack type coil on the outer peripheral side of the rotor coil 11 and the racetrack type coil on the central side have substantially the same width (thickness) in the circumferential direction (direction intersecting the stacking direction). The same applies to the stator coil 21. The race track type coil on the outer peripheral side of the stator coil 21 and the race track type coil on the central side have substantially the same width in the circumferential direction.

  Since the circumferential widths of the stacked racetrack coils are substantially equal, the number of turns of each racetrack coil is substantially equal in the rotor coil 11 and the stator coil 21 of the second embodiment. Also in this case, as shown in FIG. 3, if each race track type coil is wound, the inner diameter of the race track type coil can be changed for each race track type coil.

  Specifically, as shown in FIG. 3, with respect to the rotor coil 11, the inner diameter of the racetrack type coil extends from one end (that is, the center side) in the laminating direction of the racetrack type coil to the other end (ie, the outer peripheral side). Is preferably gradually increased. If it does in this way, a race track type coil can be wound so that it may not pass through the high magnetic field field 1a which exists in the field of the perimeter side of rotor core 13. Here, since the number of turns of each laminated racetrack coil is almost equal, not only the inner diameter but also the outer diameter of the racetrack coil is from one end (center side) of the racetrack coil in the lamination direction. The superconducting wire is wound so as to gradually increase toward the other end (outer peripheral side).

  Similarly to the rotor coil 11, the stator coil 21 also has an inner diameter of the racetrack type coil that gradually increases from one end (outer peripheral side) to the other end (center side) in the laminating direction of the racetrack type coil. Has been placed. In this way, the superconducting wire constituting the racetrack coil can be wound so as not to pass through the high magnetic field region 1b existing in the central region of the stator core 23. Here, not only the inner diameter of the racetrack type coil but also the outer diameter is such that the superconducting wire gradually increases from one end (outer peripheral side) to the other end (center side) in the laminating direction of the racetrack type coil. It is wound.

  Even in this case, like the motor 100 in the first embodiment, the racetrack coil is wound around the high magnetic field regions 1a and 1b, thereby improving the electrical characteristics of the superconducting current in the racetrack coil. Can be made. Further, the number of racetrack coils is ensured by arranging the racetrack coils on the outer peripheral sides (in the radial direction of the racetrack coils) of the high magnetic field regions 1a and 1b. For this reason, the output of the motor 100 can be maintained by ensuring the space factor of the racetrack coil.

  In the motor 100 of the second embodiment, as in the motor 100 of the first embodiment, the race track having the above-described mode is applied to only one of the rotor 10 and the stator 20, for example, depending on the situation. The other racetrack coil may be the same as that shown in FIG. Further, for example, the racetrack type coil (the number of turns is changed) in the first embodiment for one of the rotor 10 and the stator 20, and the racetrack type coil (the number of turns) in the second embodiment is used for the other. May be constant).

  As described above, the second embodiment differs from the first embodiment only in the winding state of the racetrack coil. Therefore, the configuration, conditions, procedures, effects, and the like that have not been described above for the second embodiment are all in accordance with the first embodiment.

  The electric characteristics of the superconducting coil in the motor 100 according to the first embodiment described above were compared with the electric characteristics of the superconducting coil in the conventional motor. The details will be described below.

  Here, the evaluation was performed using the motor 100 according to the first embodiment shown in the schematic cross-sectional view of FIG. 2 and the conventional motor shown in the schematic cross-sectional view of FIG. 5 described above. The motor shown in FIG. 2 and the motor shown in FIG. 5 are different in how the rotor coil 11 and the stator coil 21 are wound, but the other configurations are all the same. Specifically, as described above, the motor of FIG. 2 changes the number of turns of the racetrack coil so that the rotor coil 11 and the stator coil 21 do not pass through the high magnetic field region 1a and the high magnetic field region 1b, respectively. Has been placed. On the other hand, in the motor of FIG. 5, the number of turns of each laminated racetrack coil is the same, and the inner diameter and the outer diameter are all the same. Therefore, the rotor coil 11 and the stator coil 21 pass through the high magnetic field region 1a and the high magnetic field region 1b, respectively. The dimensions of the motor of FIG. 2 and the motor of FIG. 5 are as shown in Table 1 below.

  “Motor outer diameter” in Table 1 refers to a coil cover (not shown in FIGS. 2 and 5) disposed outside the outer periphery of the stator 20 in the cross-sectional views of the motors shown in FIGS. It is the diameter of the cross section of the whole motor including. “Motor thickness” is the length in the extending direction of the output shaft 18 shown in FIGS. 2 and 5. The “rotor inner diameter” is the circular diameter of the cross section of the output shaft 18 shown in FIGS. 2 and 5. The “rotor outer diameter” is the diameter of the outer peripheral portion of the rotor core 13 shown in FIGS. 2 and 5. The “stator inner diameter” is the diameter of the inner peripheral portion (region facing the outer peripheral portion of the rotor core 13) of the stator 20 shown in FIGS. The “outer diameter of the stator” is the diameter of the outer peripheral portion of the stator 20 shown in FIGS. 2 and 5. The “gap length” is the width of a gap sandwiched between the outer peripheral portion of the rotor core 13 and the inner peripheral portion of the stator 20. The “back yoke width” is the distance between the outermost part of the region around which the stator coil 21 is wound and the outer peripheral portion of the stator 20. The “cross-sectional dimension of the wire” is a rectangular dimension indicated by a cross section intersecting with the extending direction of the superconducting wire constituting the rotor coil 11 and the stator coil 21.

  As shown in FIGS. 2 and 5, the rotor coil 11 of each motor having such dimensions has a configuration in which four layers of racetrack coils are laminated. The number of turns (number of windings) of the four-layer racetrack type coil of the rotor coil 11 in FIG. 2 is 40 turns for the racetrack type coil on the most central side, and 30 for the racetrack type coil laminated thereon. There are 20 turns for the race track type coil laminated on the turn, and 10 turns for the race track type coil laminated on the outermost side (most outermost side). Further, in the rotor coil 11 of FIG. 5, each of the four layers of the racetrack coil has 25 turns. 2 and the rotor coil 11 of the motor of FIG. 5 has a total number of turns of 100, and the design value of the superconducting current flowing through the coil in actual use is 20A.

  Similarly, the stator coil 21 of each motor has a structure in which three layers of racetrack coils are laminated as shown in FIGS. 2 and 5. In the stator coil 21 of FIG. 2, the number of turns of the three-layer racetrack type coil is 50 turns for the outermost racetrack type coil, 30 turns for the racetrack type coil laminated thereon, and further thereon. The laminated (most central) racetrack coil has 10 turns. Further, for the stator coil 21 of FIG. 5, each of the three layers of the racetrack coil has 30 turns. 2 and the stator coil 21 of the motor of FIG. 5 has a total number of turns of 90, and the design value of the superconducting current flowing through the coil in actual use is 100A.

  Table 2 below shows the results of investigating whether or not energization operation by flowing a desired superconducting current is possible for each motor including each coil having the number of turns and the shape described above. All of these coils were formed using a Bi-based superconducting wire formed by filling a powder as a superconductor into a tube and performing wire drawing, sintering, or the like.

  In Table 2, for each of the motor of FIG. 2 and the motor of FIG. 5 shown in “Cross-sectional shape”, the “Number of layers” column indicates the number of layers of the racetrack coil and “Number of turns of coil”. In the column, the number of turns and the total sum of each of the racetrack coils stacked above are shown in the “Current Design Value” column, and the design value of the superconducting current flowing through the coil in actual use. “Coil applied vertical magnetic field” means a vertical magnetic field applied to the superconducting wire constituting the coil when the coil is used under a temperature condition of 65K (the intensity of the magnetic field applied in the direction perpendicular to the main surface of the superconducting wire). ). In the “energization” column, “o (possible)” or “x (impossible)” indicates whether or not a superconducting current as designed can flow through the coil.

  From Table 2, it is possible for the rotor coil 11 to flow a superconducting current as designed to drive the motor for both the coil of FIG. 2 and the coil of FIG. When the coil applied vertical magnetic field in the rotor coil 11 of the motor of FIG. 2 is measured, it is 0.54T as shown in Table 2, and the measurement result of the coil applied vertical magnetic field in the rotor coil 11 of the motor of FIG. there were. As a result, since the superconducting current required for driving the motor is as low as 20 A, the rotor coil 11 according to the winding aspect of the present invention is used even when the rotor coil 11 according to the conventional winding aspect is used. In the same manner, data for enabling energization was obtained. However, the magnitude of the vertical magnetic field applied to the rotor coil 11 when energized is larger than that in the case of using the rotor coil 11 according to the conventional winding mode (FIG. 5), according to the winding mode (FIG. 2) of the present invention. The use of is slightly reduced. Since the vertical magnetic field is considered to be a cause of deteriorating the electric characteristics of the superconducting coil, it can be said that the electric field can be improved by reducing the vertical magnetic field applied to the rotor coil 11 by the winding mode of the present invention.

  As for the stator coil 21, it is possible to flow a superconducting current as designed for driving the motor for the coil of FIG. However, no current can flow through the coil of FIG. The magnitude of the coil-applied vertical magnetic field of the stator coil 21 during driving is 0.46 T for the stator coil 21 according to the conventional winding mode (FIG. 5), whereas it is according to the winding mode (FIG. 2) of the present invention. The stator coil 21 is greatly reduced to 0.32T. Therefore, the stator coil 21 according to the conventional winding mode (FIG. 5) has a large vertical magnetic field and cannot pass a desired current through the coil, whereas the stator coil according to the winding mode (FIG. 2) of the present invention. A desired current can be supplied to the coil 21.

  Note that whether or not energization is possible is determined with reference to the data shown in FIG. In the graph of FIG. 4, the horizontal axis indicates the magnitude of the magnetic field applied to the superconducting wire used for each of the racetrack coils described above, and the vertical axis indicates the critical current when each magnitude of magnetic field is applied to the coil. The magnitude of Ic (A) is shown. The data in FIG. 4 is data obtained when the superconducting wire is used under a temperature condition of 65K, similarly to the condition when the data shown in Table 2 is extracted. The superconducting wire has a critical current Ic of 180 A under a condition of 77K and a vertical magnetic field of 0T. A broken line 101 indicates data when a parallel magnetic field is applied to the superconducting wire, and a broken line 102 indicates data when a vertical magnetic field is applied to the superconducting wire. Here, the parallel magnetic field means a magnetic field applied in the direction along the width direction or the major axis direction of the superconducting wire constituting the coil (that is, the direction intersecting the thickness direction (height direction)).

  As shown in FIG. 4, the critical current Ic, which is the maximum value of the current that can flow through the superconducting wire, is lower when a vertical magnetic field is applied than when a parallel magnetic field is applied to the superconducting wire. When a vertical magnetic field of 0.46 T is applied as in the stator coil 21 of the conventional winding mode (FIG. 5) shown in Table 2 above, the critical current Ic is about 80 A from FIG. Therefore, it is impossible to flow 100 A, which is the design value of the current of the stator coil 21. Conversely, for example, when a 0.32 T vertical magnetic field is applied as in the stator coil 21 of the winding mode of the present invention (FIG. 2), the critical current is about 110 A from FIG. Therefore, 100 A, which is a design value of the current of the stator coil 21, can be passed.

  As described above, the embodiments and examples of the present invention have been described. However, the embodiments and examples disclosed this time should be considered as illustrative in all points and not restrictive. It is. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention is particularly excellent as a technique for improving the electrical characteristics of a superconducting coil and a superconducting device using the superconducting coil.

  1a, 1b High magnetic field region, 10 rotor, 11 rotor coil, 13 rotor core, 16 rotor shaft, 17 coil cooling vessel, 18 output shaft, 20 stator, 21 stator coil, 23 stator core, 30 motor body, 35 bearing, 100 motor , 101, 102 Polyline.

Claims (4)

A rotor using a superconducting coil in which a plurality of racetrack coils are laminated,
The inner diameter of the plurality of the racetrack coil used for the rotor, Ri gradually increases Na toward the outer peripheral side from the center side of the rotor,
Having a rotor core extending radially from the center side of the rotor;
A rotor having a gap between the rotor core and the racetrack coil wound around the rotor core on the outer peripheral side .   2. The rotor according to claim 1, wherein the plurality of racetrack coils used in the rotor have a larger number of turns on a central side of the rotor than the number of turns on an outer peripheral side of the rotor. A stator using a superconducting coil in which a plurality of racetrack coils are laminated,
The inner diameter of the plurality of the racetrack coil used for the stator, Ri gradually increases Na toward the center side from the outer peripheral side of said stator,
A stator core extending so as to protrude toward the center of the stator,
A stator having a gap between the stator core and the racetrack coil wound around the stator core at a center side .   4. The stator according to claim 3, wherein the plurality of racetrack coils used in the stator have a greater number of turns on the outer peripheral side of the stator than the number of turns on the center side of the stator.

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