JP2012143043A - Superconducting motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a superconducting motor that efficiently cools superconducting coils to a desired cryogenic temperature while reducing variations in temperature of the superconducting coils.SOLUTION: The superconducting motor includes a rotatably arranged rotor, and a stator radially opposed to the rotor and having the coils. The superconducting motor includes a refrigerator 14 having capillaries 66 for conducting a low temperature refrigerant therein, and the capillaries 66 include a coil wrapping portion 100 wrapping the coil 36. The coil wrapping portion 100 has a side straight portion 102 disposed along and in thermal contact with a side plate portion 96 of a peripheral portion of the coil 36 directed to one side of the circumference of the stator, an opposite side straight portion 104 disposed along and in thermal contact with an opposite side plate portion 97 of the peripheral portion of the coil 36 directed to the other side of the circumference of the stator, a coupling portion 106 coupling both straight portions 102, 104.

Description

  The present invention relates to a superconducting motor, and more particularly, to a superconducting motor including a refrigerator having at least one thin tube through which a low-temperature refrigerant flows.

  Conventionally, a superconducting motor including a refrigerator has been considered. For example, Japanese Patent Laying-Open No. 2010-178517 (Patent Document 1) describes a superconducting motor device including a superconducting motor, a cryogenic temperature generator, and a container. The superconducting motor includes a rotor having a rotatable rotating shaft and a plurality of permanent magnets arranged on the outer periphery of the rotating shaft, and a stator. The stator has a three-phase superconducting coil wound around the teeth of the stator core. The cryogenic temperature generator includes a refrigerator that generates cryogenic temperatures in the cold head. A heat conduction part having high heat conductivity is provided for connecting the cold head and the stator iron core of the superconducting motor stator so that heat can be transferred. The cooling cylinder portion of the heat conducting portion is cooled to a cryogenic state, and is in thermal contact with the outer peripheral portion of the stator core to cool the stator core. The container forms a vacuum heat insulating chamber that insulates the superconducting coil. For this reason, even if heat intrusion occurs on the superconducting coil side or the refrigeration output of the refrigerator cannot catch up, the stator core is supposed to maintain the superconducting coil in a low temperature state. Further, FIG. 3 of Patent Document 1 describes that a heat conductive material having high thermal conductivity is provided between the teeth portion of the stator core and the superconducting coil. Similarly, FIG. It is described that a heat conductive material is connected to a heat conductive portion surrounding an outer peripheral portion via a connecting portion. With this configuration, there is a possibility that the superconducting coil can be cooled via the tooth portion cooled by the cryogenic temperature generating portion.

  In addition, International Publication No. 03 / 001127A1 pamphlet (Patent Document 2) includes a pressure control means having a compressor, a high-pressure switching valve and a low-pressure switching valve, an expansion / compression section having a room temperature end and a low temperature end, A cold storage type refrigerator that includes a cold storage unit having a room temperature end and a low temperature end and transfers heat to the object to be cooled is described. The cold storage type refrigerator is connected to the low temperature end of the expansion / compression section and the low temperature end of the cold storage section, and is provided with a working gas passage extending to the object to be cooled. The pulse tube refrigerator is said to play an important role as a cooling means for sensors and semiconductor devices.

JP 2010-178517 A International Publication No. 03 / 001127A1 Pamphlet

  Conventionally, like the superconducting motor described in Patent Document 1, when cooling a superconducting coil, cold transmission is performed by various methods. However, a superconducting coil using a solid heat conducting material is used. The heat conductivity of the heat conducting material is finite, and when a heat amount is passed through a heat conducting material with a finite length, a temperature difference proportional to the amount of heat that flows will occur, so cooling efficiency will be improved. Is difficult. For this reason, there is room for improvement in terms of improving the cooling efficiency of the superconducting coil, achieving early cooling, and generating a stable superconducting state at an early stage.

  Further, in order to improve the cooling performance of the superconducting motor, it is conceivable that the superconducting coil is directly brought into contact with the superconducting coil and the superconducting coil is cooled by the heat conducting material. However, the length of the superconducting coil in the axial direction of the stator tends to be large, and when the superconducting coil is cooled only in a narrow range in the axial direction of the superconducting coil, the superconducting coil is reduced while reducing the temperature deviation of the superconducting coil. Difficult to cool. On the other hand, in order to avoid the failure of the superconducting state of the superconducting coil, it is considered to adopt a supercooling means for lowering the temperature of the superconducting coil, for example, 77K, further lower than the temperature for realizing the normal superconducting state. It is done. However, in this case, the power consumption of the refrigerator becomes excessive accordingly. Therefore, there is room for improvement in terms of efficiently cooling the superconducting coil while reducing the temperature deviation of the superconducting coil, such as cooling the superconducting coil uniformly.

  Patent Document 2 merely describes a regenerative refrigerator, and does not disclose the use of the refrigerator for cooling a superconducting coil of a superconducting motor.

  An object of the present invention is to efficiently cool a superconducting coil to a desired cryogenic temperature while reducing the temperature deviation of the superconducting coil in a superconducting motor.

  A superconducting motor according to the present invention includes a rotor that is rotatably disposed and a stator that is disposed so as to face the rotor in a radial direction, and the stator includes a stator core and a plurality of superconducting coils that are composed of superconducting wires. The stator core has an annular back yoke, a plurality of teeth protruding radially at one end of the back yoke in the radial direction, and a slot provided between adjacent teeth in the circumferential direction, and the plurality of superconducting coils are And a superconducting motor wound around the teeth, further comprising a refrigerator having at least one thin tube through which a low-temperature refrigerant flows, and the thin tube includes a coil surrounding arrangement portion arranged around the superconducting coil. The coil peripheral arrangement portion is provided in the thin tube, and the circumferential direction of the stator out of the outer peripheral portion of the superconducting coil is directed from one axial side to the other side of the stator Of the superconducting coil in the outer circumferential portion of the superconducting coil, and the other side of the outer circumferential portion of the superconducting coil so as to be in thermal contact with the outer circumferential portion of the stator. The other side arrangement part which is arranged along the other side outer circumference part facing the side and is in thermal contact with the other side outer circumference part, and the connection part which couples the one side arrangement part and the other side arrangement parts to each other on the same side in the axial direction of the stator It is a superconducting motor characterized by having. In addition, the term “thermal contact” in the entire specification and claims includes not only direct contact between members that transfer heat to each other but also contact through members having thermal conductivity.

  Moreover, in the superconducting motor according to the present invention, preferably, the one-side arrangement portion is arranged in the axial direction along the one-side outer circumferential portion facing the circumferential direction one side of the stator among the outer circumference portions of the superconducting coil, and is arranged on the other side. The portion is disposed in the axial direction along the outer peripheral portion of the superconducting coil along the other outer peripheral portion facing the other side in the circumferential direction of the stator.

  In the superconducting motor according to the present invention, preferably, the coil peripheral arrangement portion is formed in a U shape and is fitted to the outer peripheral portion of the superconducting coil.

  In the superconducting motor according to the present invention, preferably, the coil peripheral arrangement portion is fitted to the outer peripheral portion of the superconducting coil so as to go from the other side in the axial direction of the stator to one side.

  In the superconducting motor according to the present invention, preferably, the arc portion provided in the connecting portion and having the smallest radius of curvature in the free state is in the free state and the other axial end portion of the stator in the outer peripheral portion of the superconducting coil. And has an inner radius of curvature Rc smaller than the radius of curvature Rs of the portion facing the arc portion.

  Moreover, in the superconducting motor according to the present invention, preferably, the inner width dimension Bc between the one-side arranged portions and the other-side arranged portions in the free state of the coil surrounding arranged portions is the one-side outer peripheral portion and the other outer peripheral portion of the superconducting coil. It is made smaller than the width dimension Bs.

  Moreover, in the superconducting motor according to the present invention, preferably, the coil peripheral arrangement portion is joined to the outer peripheral portion of the superconducting coil by a high thermal conductive adhesive. Preferably, the high thermal conductive adhesive is an adhesive containing a filler such as a material having good thermal conductivity such as silica and alumina. More preferably, an adhesive having no low temperature brittleness is used.

  According to the superconducting motor according to the present invention, the at least one thin tube that is provided in the refrigerator and allows the low-temperature refrigerant to flow inside includes the coil surrounding arrangement portion arranged around the superconducting coil. The superconducting coil can be directly contacted, and the superconducting coil can be efficiently cooled to a desired cryogenic temperature. Further, the coil peripheral arrangement portion can be cooled by contacting over a wide range in the axial direction of the stator in the outer peripheral portion of the superconducting coil. For this reason, it is possible to efficiently cool the superconducting coil while reducing the temperature deviation of the superconducting coil, such as cooling the superconducting coil uniformly without excessively consuming the power consumption of the refrigerator.

It is sectional drawing along the axial direction which shows the superconducting motor of the 1st Embodiment of this invention. It is an enlarged view of the AA cross section of FIG. It is a figure which shows the basic composition of the refrigerator used in 1st Embodiment in the state which made all the thin tubes linear. It is BB sectional drawing of FIG. It is a figure corresponding to the expanded cross section of the C section of FIG. It is a perspective view which takes out and shows a part of thin tube from FIG. 1, and the 1 superconducting coil fitted by this thin tube. It is a figure which shows the state just before fitting a thin tube with the superconducting coil of FIG. It is sectional drawing along the axial direction which shows the superconducting motor of the comparative example remove | deviated from this invention. It is DD sectional drawing of FIG. In the superconducting motor of the 2nd Embodiment of this invention, it is a figure which takes out and shows a part of thin tube and one superconducting coil fitted by this thin tube. It is a figure which shows the state just before fitting a thin tube with the superconducting coil of FIG. It is a figure which takes out and shows a part of thin tube and one superconducting coil fitted by this thin tube in the superconducting motor of the 3rd Embodiment of this invention. It is a figure which shows the state just before fitting a thin tube with the superconducting coil of FIG. It is a figure corresponding to FIG. 5 which shows the superconducting motor of the 4th Embodiment of this invention. It is a figure corresponding to FIG. 5 which shows the superconducting motor of the 5th Embodiment of this invention.

[First Embodiment]
Embodiments according to the present invention will be described below in detail with reference to the drawings. In this description, specific shapes, materials, numerical values, directions, and the like are examples for facilitating the understanding of the present invention, and can be appropriately changed according to the application, purpose, specification, and the like.

  1 to 7 show a superconducting motor according to a first embodiment of the present invention. As shown in FIGS. 1 and 2, the superconducting motor 10 includes a motor body 12 and a refrigerator 14 for cooling the motor body 12. The motor body 12 includes a motor case 16, a rotating shaft 18 rotatably supported by the motor case 16, and a rotor disposed rotatably by being fixed to the outside of the rotating shaft 18 inside the motor case 16. 20 and so on. The motor main body 12 includes a substantially cylindrical stator 22 that is fixed to the inner peripheral surface of the motor case 16 so as to be opposed to the radially outer side of the rotor 20. The refrigerator 14 is fixed to the motor case 16. In the following description, unless otherwise specified, the direction along the central axis X of the rotation shaft 18 is referred to as the axial direction, the radial direction perpendicular to the rotation central axis X is referred to as the radial direction, and the rotation central axis. A direction along a circle drawn around X is called a circumferential direction.

  The rotor 20 includes, for example, a cylindrical rotor core 24 formed by laminating electromagnetic steel plates and integrally formed by caulking, welding, or the like, and permanent magnets 26 provided at a plurality of equally spaced positions on the outer peripheral surface of the rotor core 24. That is, a plurality of (six in the example shown in FIG. 2) permanent magnets 26 are fixed to the outer peripheral surface of the rotor core 24 at equal intervals in the circumferential direction. The permanent magnet 26 is magnetized in the radial direction, and the magnetization direction is alternately varied in the circumferential direction. For this reason, the N pole and the S pole are alternately arranged on the outer peripheral surface of the rotor 20. However, the permanent magnet 26 provided in the rotor 20 may not be exposed on the outer peripheral surface, and may be embedded in the vicinity of the outer peripheral surface. Such a rotor 20 is fixed to the outer peripheral surface of the rotary shaft 18 made of a round steel bar or the like.

  The rotating shaft 18 is rotatably supported at both ends thereof by bearings 32 fixed to disk-shaped end plates 28 and 30 constituting both ends of the motor case 16. Thus, when a rotating magnetic field is generated inside the stator 22, the rotor 20 rotates under the influence.

  The stator 22 includes a stator core 34 that is a substantially cylindrical stator core, and a coil 36 that is a superconducting coil. That is, the stator core 34 protrudes in the radial direction at an annular back yoke 38 and a plurality of circumferentially equally spaced locations (9 locations in the example shown in FIG. 2) at the inner circumferential end, which is one radial end of the back yoke 38. And a tooth 40 provided to do so. In addition, the stator core 34 has slots 42 (FIG. 2) at equal intervals provided at a plurality of circumferential positions (9 positions in the illustrated example) provided between adjacent teeth 40 in the circumferential direction of the inner peripheral portion of the back yoke 38. Have. The stator core 34 can be configured by, for example, laminating a plurality of substantially annular electromagnetic steel plates in the axial direction and assembling them integrally by caulking, bonding, welding, or the like. However, the stator core may be manufactured by arranging a plurality of divided cores each having one tooth in a ring shape and fastening them with a cylindrical fastening member from the outside. The split core may be made of a dust core.

  A plurality of coils 36 made of a superconducting wire are wound around the plurality of teeth 40 of the stator core 34 by concentrated winding. Further, as shown in FIG. 6 described later, the superconducting wire constitutes a coil 36 by winding a rectangular wire having a rectangular cross section in a flatwise shape. For example, the coil 36 is configured by winding a flat wire around a pancake wound in a substantially oval spiral shape. However, the winding method of the coil 36 is not limited to such a configuration, and for example, it may be configured by winding a rectangular wire with a solenoid winding. Further, the superconducting wire is not limited to a rectangular wire, and for example, the cross-sectional shape may be circular. For the superconducting wire, for example, an yttrium superconducting material or a bismuth superconducting material can be suitably used. However, the superconducting material constituting the superconducting wire is not limited to these, and may be another known superconducting material or a superconducting material developed in the future and exhibiting superconducting characteristics at a higher temperature.

  The superconducting wire constituting the coil 36 may be covered with insulation. Thereby, when it winds closely as the coil 36, the electrical insulation between each turn is ensured. However, when the superconducting wire is not covered with insulation, when the coil 36 is formed, electrical insulation between the turns may be ensured by winding the coil 36 while sandwiching insulating paper or an insulating film.

  The coil 36 includes slot arrangement portions 44 positioned in slots 42 (FIG. 2) provided at a plurality of locations of the stator core 34, and coil end portions 46 on both sides projecting axially outward from both axial end surfaces of the stator core 34. including. Each coil 36 is connected in series with every other coil 36 and constitutes a U, V, W phase coil. One end of each phase coil is connected to each other at a neutral point (not shown), and the other end of each phase coil is connected to each phase current introduction terminal (not shown).

  Further, as shown in FIG. 7, the coil 36 is configured to have a substantially oval shape when viewed in the radial direction of the stator 22. That is, the coil 36 includes plate portions 96 and 97 that are substantially parallel to each other, and a partial cylindrical portion 98 that is provided on both ends of the plate portions 96 and 97 and has a substantially semicircular cross section that constitutes the coil end portion 46.

  As shown in FIG. 1, the motor case 16 accommodates the rotor 20 and the stator 22, and the outer peripheral edge portion is airtight at the cylindrical outer peripheral cylindrical portion 48 and both axial end portions of the outer peripheral cylindrical portion 48. And a pair of end plates 28 and 30 coupled to each other. The outer peripheral cylinder part 48 and each end plate 28 and 30 are comprised from nonmagnetic materials, such as stainless steel, for example. In addition, the outer peripheral cylinder part 48 can also be made from a member integral with the end plate 28 (or 30) on one side.

  An inner cylinder member 50 and an intermediate cylinder member 52 each having a cylindrical shape are provided concentrically with the rotor 20 in the outer cylinder 48. Both end portions in the axial direction of the inner cylinder member 50 and the intermediate cylinder member 52 are connected to the inner surfaces of the end plates 28 and 30 so as to maintain an airtight state. The inner cylinder member 50 is preferably made of a non-metallic material (for example, FRP) that does not hinder the passage of the magnetic field and is non-conductive. More preferably, the inner cylinder member 50 is made of a low thermal conductivity material. In addition, the inner cylinder member 50 should just have a function which lets a magnetic flux pass as a basic function, and a function which can hold | maintain the vacuum in the space sealing part containing the inner cylinder member 50, and uses a nonelectroconductive material. It is not limited to what you do. For example, as the material constituting the inner cylinder member 50, a nonmagnetic material having low electrical conductivity (for example, stainless steel) can be used. On the other hand, the intermediate cylindrical member 52 is preferably made of a low thermal conductivity material (for example, FRP), and more preferably made of a nonmagnetic material having a low thermal conductivity.

  The inner cylinder member 50 has an inner diameter slightly larger than the diameter of the outermost circle of the rotor 20, and a gap is formed between the inner cylinder member 50 and the outer peripheral surface of the rotor 20. A first vacuum chamber 54 that is a cylindrical space is provided between the inner cylinder member 50 and the intermediate cylinder member 52. In the first vacuum chamber 54, the stator 22 including the coil 36 is accommodated. The outer peripheral surface of the stator core 34 constituting the stator 22 is fixed to the inner peripheral surface of the intermediate cylinder member 52.

  The first vacuum chamber 54 includes the first vacuum chamber 54 and the second vacuum chamber 56 such as the end plates 28 and 30 or the outer peripheral cylindrical portion 48 after the superconducting motor 10 is assembled including the refrigerator 14 described in detail later. A vacuum is drawn from an air vent hole (not shown) formed in at least one of the members in contact with one or both of the outer space and the outer space, and the vacuum state is maintained. In this way, the inner cylinder member 50 that does not contact the coil 36 and the stator 22 and the intermediate cylinder member 52 having a low thermal conductivity are partitioned and formed, and the interior is evacuated to be accommodated in the first vacuum chamber 54. Insulation to the stator 22 including the coil 36 can be improved.

  Further, a second vacuum chamber 56 formed of a cylindrical space is formed between the intermediate cylinder member 52 and the motor case 16. Similarly to the first vacuum chamber 54, the second vacuum chamber 56 is also in a vacuum state. The intermediate cylinder member 52 is preferably provided with a hole that allows the first vacuum chamber 54 and the second vacuum chamber 56 to communicate with each other. Thereby, the stator 22 including the coil 36 accommodated in the first vacuum chamber 54 is separated from the outside of the motor also by the second vacuum chamber 56, thereby further enhancing the heat insulating effect on the stator 22 including the coil 36. it can.

  A refrigerator 14 is fixed to the motor body 12 constituting the superconducting motor 10. Next, the basic configuration of the refrigerator 14 will be described with reference to FIGS. 3 and 4. FIG. 3 is a diagram showing the basic configuration of the refrigerator 14 used in the present embodiment in a state where all the thin tubes 66 are linear, and FIG. 4 is a cross-sectional view taken along the line BB in FIG. The refrigerator 14 is a free piston type Stirling cooler type (FPSC type) having a plurality of thin tubes 66 for circulating refrigerant gas. That is, the refrigerator 14 is provided with a pressure vibration source 58 as a refrigerator driving source provided at one end side, a regenerator 68 called a cold head whose one end is fixed to the pressure vibration source 58, and a other end side. A plurality of cooling units connected between the regenerator 68 and the second piston accommodating unit 70, the second piston accommodating unit 70 having one end fixed to the phase controller 62, and the regenerator 68 and the second piston accommodating unit 70. And a plurality of capillaries 66 made of a material having good heat conductivity. The regenerator 68 is provided with a regenerator material (not shown) inside. The regenerator 68 and the second piston housing part 70 have a heat insulating structure in which the outside is covered with a heat insulating material.

  The refrigerator 14 includes a first piston 74 that is a drive piston that linearly reciprocates in a cylinder 72 provided in the pressure vibration source 58, and the space in the cylinder 72 passes through the inside of the regenerator 68. The plurality of narrow tubes 66 communicate with each other. The refrigerator 14 also has a second piston 78 called an expansion piston or a driven piston that linearly reciprocates within a cylinder 76 provided in the second piston accommodating portion 70, and the space in the cylinder 76 is on the low temperature side. It leads to a plurality of thin tubes 66 that are heat exchange parts. A refrigerant gas (for example, He gas), which is a refrigerant, is sealed in an internal space between the first piston 74 and the second piston 78 including the plurality of thin tubes 66. That is, each narrow tube 66 is configured such that a low-temperature refrigerant gas flows inside.

  Further, the pressure vibration source 58 and the second piston accommodating portion 70 are arranged to face each other so that the moving directions of the pistons 74 and 78 are on the same straight line. The first piston 74 is connected to a mover such as a linear motor (not shown) that constitutes the pressure vibration source 58, for example, and the first piston 74 is reciprocated within the cylinder 72 by the linear motor. As the first piston 74 is driven to reciprocate, the pressure of the refrigerant gas fluctuates in the cylinder 72 of the pressure vibration source 58. Due to this pressure fluctuation, the phase controller 62 is constituted by a coil spring or a leaf spring (not shown). The second piston 78 suspended by the spring also reciprocates in a dependent manner. The phase difference between the refrigerant gas pressure fluctuation and the position fluctuation can be adjusted by the weight of the spring (not shown) and the second piston 78 and the pressure fluctuation caused by the reciprocating movement of the first piston 74. In addition, by providing a space portion that relieves pressure fluctuation caused by the reciprocating movement of the second piston 78 in the phase controller 62, the pressure of the refrigerant gas communicates with the inside of the cylinder 76 in which the second piston 78 is disposed. The phase difference between fluctuation and position fluctuation can be adjusted.

  As the first piston 74 reciprocates, the refrigerant gas is adiabatically expanded and cooled in the vicinity of the end of the narrow tube 66 of the second piston housing portion 70, so that the refrigerant gas flowing inside each narrow tube 66 is also cooled. As described above, the compression and expansion of the refrigerant gas are repeated between the first piston 74 and the second piston 78, whereby each capillary 66 through which the refrigerant gas flows is cooled.

  The refrigerator 14 has a cooling performance in which the coil 36 made of a superconducting wire can be cooled to a desired cryogenic temperature (for example, about 70 K) at which superconducting characteristics are exhibited, and the cooling temperature is controlled by controlling the stroke of the first piston 74. Can be adjusted. For this purpose, the stroke of the first piston 74 is controlled by a control unit (not shown). The control unit can also be configured to control the cooling temperature of the refrigerator 14 according to the load of the superconducting motor 10 (FIG. 1). For example, the cooling temperature can be lowered as the load of the superconducting motor 10 increases. When the superconducting motor 10 is mounted on an electric vehicle such as an electric vehicle as a driving power source, the refrigerator 14 is preferably small and light in order to limit installation space and reduce the vehicle weight. As described above, when the FPSC type is used for the refrigerator 14, the size and weight can be reduced.

  In the present embodiment, the refrigerator 14 having such a basic configuration is fixed to the motor body 12 (FIG. 1). That is, as shown in FIG. 1, in the superconducting motor 10, the pressure constituting the refrigerator 14 is located on a part of the end plate 28 in the circumferential direction (upper part in FIG. 1) located on one side in the axial direction (right side in FIG. 1). A cylindrical first bracket 60 on the vibration source 58 side is fixed, and in the end plate 28 on one side, on the side opposite to the pressure vibration source 58 in the diameter direction of the rotary shaft 18 (the lower side in FIG. 1) 14 is fixed to the cylindrical second bracket 64 on the phase controller 62 side. In addition, one end of the regenerator 68 and one end of the second piston housing part 70 protrude into the first vacuum chamber 54 via the inside of the first bracket 60 or the second bracket 64, respectively.

  Further, as shown in FIG. 2, the two intermediate portions in the longitudinal direction of the plurality of thin tubes 66 that are the low temperature side heat exchange portions are respectively inserted into two adjacent slots 42 in the stator core 34. Has been placed. That is, as shown in FIGS. 5 and 6, each narrow tube 66 includes a substantially U-shaped coil peripheral arrangement portion 100 that is provided at an intermediate portion in the length direction and is arranged so as to fit around the coil 36. . For this purpose, the coil peripheral arrangement portion 100 is provided in the middle portion of the narrow tube 66, and includes the one-side straight portion 102 that is one-side placement portion that is connected to each other, And has a substantially U-shape as a whole. Among these, the one-side straight portion 102 is directed from one axial side of the stator 22 (FIG. 1) (right side of FIG. 1, left side of FIG. 6) to the other axial side (left side of FIG. 1, right side of FIG. 6). The coil 36 is disposed in the axial direction along the outer surface of the one-side plate portion 96 that is the one-side outer peripheral portion facing the one side in the circumferential direction of the stator 22 (the upper side in FIG. 5, the back side in FIG. 6). The one side plate portion 96 is in thermal contact.

  Further, the other side straight portion 104 of the coil 36 extends from one axial side of the stator 22 (right side in FIG. 1, left side in FIG. 6) to the other axial side (left side in FIG. 1, right side in FIG. 6). Among the outer peripheral portions, the outer peripheral portion 97 is disposed in the axial direction along the outer surface of the other side plate portion 97 that is the other outer peripheral portion facing the other side in the circumferential direction (front side in FIG. 6). In contact. The connecting portion 106 includes an arc portion 108 provided in a substantially semicircular shape. The entire connecting portion 106 may be constituted by the arc portion 108. The connecting portion 106 connects one ends of the one-side straight portion 102 and the other-side straight portion 104 on the same side in the axial direction of the stator 22. For this reason, the one-side straight portion 102 and the other-side straight portion 104 are linear and arranged in parallel with the rotation center axis X of the rotation shaft 18. Further, the one-side straight portion 102 and the other-side straight portion 104 are arranged at the same position in the radial direction of the stator 22 in the outer peripheral portion of the coil 36. For this reason, the straight portions 102 and 104 are arranged on a virtual plane substantially orthogonal to the winding axis center O of the coil 36. The other end of the one-side straight portion 102 is connected to the regenerator 68 directly or via another portion of the narrow tube 66, and the other-side straight portion 104 is connected to the second piston housing portion directly or via another portion of the thin tube 66. 70. As described above, the plurality of thin tubes 66 each have a substantially U-shaped coil peripheral arrangement portion 100 fitted to the outer peripheral portion of the coil 36 arranged at a plurality of different locations in the circumferential direction of the stator 22.

  Further, the coil peripheral arrangement portion 100 is fitted to the outer peripheral portion of the coil 36 so as to be directed from one axial side (left side in FIG. 1) of the stator 22 to the other axial side (right side in FIG. 1). Specifically, in the state where the other end side of each linear part 102, 104, which is the regenerator 68 and the second piston housing part 70 side of the coil peripheral arrangement part 100, is first, It is fitted along a direction parallel to the axial direction of 22. However, the coil periphery arrangement | positioning part 100 is not limited to the structure fitted in this way, For example, each coil periphery arrangement | positioning part 100 is made to the outer peripheral part of the coil 36 toward the outer peripheral side from the inner peripheral side of the stator 22. It can also be fitted.

  Further, as shown in FIG. 7, the width dimension of the outer peripheral portion of the coil 36 is Bs, and the inner width dimension of the linear portions 102 and 104 is Bc in the free state of the coil peripheral arrangement portion 100 of the narrow tube 66. Think about the case. Further, the radius of curvature inside the circular arc portion 108 which is provided in the coupling portion 106 of the narrow tube 66 and has the smallest inner diameter in a free state is Rc, and the other axial end of the stator 22 (see FIG. Rs is the radius of curvature of the outer surface of the partial cylindrical portion 98 that is located at the left end portion of 1 and the right end portion of FIG. In this case, the dimension of each part is regulated so as to satisfy one or both of Bs> Bc and Rs> Rc. For example, in the free state of the coil peripheral arrangement portion 100, the arc portion 108 has an inner curvature radius Rc (<Rs) smaller than the curvature radius Rs of the outer surface of the partial cylindrical portion 98 on the other axial end side of the stator 22. . Instead of or together with this, in the free state of the coil peripheral arrangement portion 100, the inner width dimension Bc between the one-side straight portion 102 and the other-side straight portion 104 is the plate portions 96, 97 on both sides of the coil 36. Smaller than the outer width dimension Bs (Bc <Bs).

  Further, the coil peripheral arrangement portion 100 is not only fixed by being fitted to the outer peripheral portion of the coil 36, but is also fixed by joining the coil peripheral arrangement portion 100 to the outer peripheral portion of the coil 36 with a high thermal conductive adhesive. You can also For example, an adhesive containing a filler such as silica or alumina having a good thermal conductivity is used as the high thermal conductive adhesive. More preferably, the adhesive has no low temperature brittleness, that is, brittleness at low temperature. Use the agent.

  Such a coil peripheral arrangement portion 100 is not in contact with the stator core 34. That is, each coil surrounding arrangement part 100 is in contact with only the coil 36. For this reason, the cold is transmitted from each thin tube 66 to the coil 36 through a contact portion with the coil peripheral arrangement portion 100. In such a configuration, the same number of narrow tubes 66 as the number of teeth 40 provided on the stator core 34 are provided.

  Moreover, in this structure, the high temperature side heat exchange part is comprised by the edge part arrange | positioned on the outer side of the motor case 16 of the 2nd piston accommodating part 70. FIG. Such a refrigerator 14 includes a pressure vibration source 58, a high temperature side heat exchange unit, a regenerator 68, a low temperature side heat exchange unit, and a second piston 78 (FIG. 3).

  According to such a superconducting motor 10, each of the narrow tubes 66 that constitute the refrigerator 14 and in which the low-temperature refrigerant gas flows inside includes the coil surrounding arrangement portion 100 arranged around the coil 36. The arrangement part 100 can be brought into direct contact with the coil 36, and the coil 36 can be efficiently cooled to a desired cryogenic temperature. Moreover, the coil surrounding arrangement | positioning part 100 can contact and cool over the wide range of the axial direction of the stator 22 among the outer peripheral parts of the coil 36, and can be cooled. For this reason, the coil 36 can be efficiently cooled while reducing the temperature deviation of the coil 36, such as cooling the coil 36 uniformly, without excessively consuming the power consumption of the refrigerator 14. That is, in general, a superconducting coil is extremely poor in thermal conductivity as compared with a copper wire constituting a coil of an electric motor used at normal room temperature, and thus it is difficult to cool uniformly. On the other hand, according to the present embodiment having the above-described configuration, for example, in the coil 36, unlike the configuration in which only the coil end portion 46 is cooled, the slot arrangement portion 44 of the coil 36 can be efficiently cooled. The entire coil 36, which is a superconducting coil, can be cooled more uniformly. That is, the coil 36 can be efficiently cooled while reducing the deviation of the temperature distribution of the entire coil 36.

  Further, since the coil peripheral arrangement portion 100 is fitted to the outer peripheral portion of the coil 36, it is possible to ensure adhesion between the thin tube 66 and the coil 36, improve the cooling efficiency of the coil 36, and connect the thin tube 66 to the coil 36. Can be easily installed. For this reason, the attachment property of the thin tube 66 can be improved. Further, since the thin tube 66 is supported by the coil 36, the thin tube 66 is hardly rattled during use, and the structure of the superconducting wire constituting the coil 36 can be hardly broken.

  In addition, since the coil 36 is cooled by the thin tube 66 without using the stator core 34 having a large heat capacity, the coil 36 is cooled early at the start-up while suppressing power consumption, and the time required to reach the superconducting state can be shortened. As a result, the coil 36 can be efficiently cooled to a desired cryogenic temperature, and a superconducting state of the coil 36 can be created early at the time of starting.

  Each narrow tube 66 has a one-side straight portion 102 and an other-side straight portion 104 which are extended portions extending in a direction parallel to the axial direction of the stator 22 in two slots 42, and each straight portion 102 and 104 are in contact with only the coil 36 in the slot 42. Thus, since the straight portions 102 and 104 do not contact the stator core 34 by the back yoke 38 or the like, the cold can be transmitted from the narrow tube 66 to the coil 36 more efficiently, and the coil 36 can be cooled earlier at the time of starting. .

  Further, the width dimension of the outer peripheral portion of the coil 36 is Bs, the inner width dimension between the linear portions 102 and 104 provided in the coil peripheral arrangement portion 100 is Bc, and the coil 36 is provided in the connecting portion 106 of the narrow tube 66, and is in a free state. The radius of curvature inside the circular arc portion 108 having the smallest inner diameter is Rc, and the cross-sectional circular arc is a portion located at the other axial end of the stator 22 and facing the circular arc portion 108 in the outer peripheral portion of the coil 36. When the radius of curvature of the outer surface of the shape partial cylindrical portion 98 is Rs, the dimensions of each portion are regulated so as to satisfy one or both of Bs> Bc and Rs> Rc. For this reason, the contact pressure and adhesion between the coil peripheral arrangement portion 100 and the coil 36 can be increased, and the narrow tube 66 can be fixed to the coil 36 more easily. In addition, by appropriately adjusting the radius of curvature Rc of the arc portion 108, the narrow tube 66 can be brought into sufficient contact with the coil 36 while effectively preventing the destruction of the internal structure of the dense superconducting wire constituting the coil 36. it can.

  In addition, the adhesiveness between the narrow tube 66 and the coil 36 can be adjusted by appropriately adjusting the radius of curvature Rc of the arc portion 108. Furthermore, by providing a notch or the like which is a fine notch in the arc portion 108, it is possible to adjust the adhesion between the narrow tube 66 and the coil 36 and the fixing strength. Further, by adjusting the coefficient of thermal expansion between the superconducting wire and the material constituting the thin tube 66, the adhesion between the coil 36 and the thin tube 66 can be adjusted.

  Further, when the coil peripheral arrangement portion 100 is fixed to the outer peripheral portion of the coil 36 by bonding with a high thermal conductive adhesive, the coil peripheral arrangement portion 100 contacts the outer peripheral portion of the coil 36 by point contact or line contact. However, the heat transfer property can be improved by the high heat conductive adhesive interposed therebetween, and the cooling property for the coil 36 can be improved. Further, the thin tube 66 can be fixed to the coil 36 with higher strength.

  As shown in FIG. 5, the coil 36 is brought into contact with the outer peripheral portion of the tooth 40 via an insulator 110 having electrical insulation (not shown in FIG. 2), but the insulator 110 is thick. Or a material with poor thermal conductivity, or a shape that reduces the thermal conductivity. According to this configuration, the cooling path from the coil 36 to the stator core 34 can be cut off, and the cooling performance for the coil 36 can be further improved. For example, as the insulator 110 having a shape that reduces the thermal conductivity, the longitudinal ends of a comb tooth piece having comb teeth on one side are connected in an annular shape, or both ends of a plate portion are connected in an annular shape in a plurality of circumferential directions. In this case, a hole having a hole penetrating in the thickness direction is used. Further, the insulator 110 can be made of a material having poor thermal conductivity such as glass fiber reinforced resin (GFRP).

  Further, by configuring the insulator 110 with a flexible material such as PE, the adhesion between the coil 36 and the thin tube 66 and the adhesion between the turns of the coil 36 are improved, and each turn of the coil 36 is improved. It is possible to improve the heat transfer property to and to more effectively prevent the destruction of the internal structure of the dense superconducting wire.

  FIG. 8 is a cross-sectional view along the axial direction showing a superconducting motor of a comparative example deviating from the present invention. 9 is a cross-sectional view taken along the line DD of FIG. The superconducting motor 10 of the comparative example shown in FIGS. 8 and 9 is provided with a pair of refrigerators 82 on both sides of the motor main body 12 instead of the refrigerator 14 (FIG. 1 and the like) in the structure of the present embodiment. It has a structure like that. That is, unlike the above-described refrigerator 14, each refrigerator 82 is a FPSC type that is not provided with a thin tube for flowing a refrigerant, and is connected to a gas compressor 84 that is a pressure vibration source and the gas compressor 84. And a regenerator 86 as a cooling unit. The regenerator 86 is in contact with the disk-shaped heat transfer member 90 through the inside of a cylindrical bracket 88 fixed to the end plate 28. One surface of each heat transfer member 90 is in contact with the axially outer end portion of the coil end portion 46.

  In the refrigerator 82, a piston (not shown) reciprocates in a cylinder (not shown) provided inside the gas compressor 84 to repeatedly compress and expand the refrigerant gas, whereby the regenerator 86 and the heat transfer member. Each coil 36 is cooled via 90. Even with such a configuration, the coil 36 can be cooled, but there is room for improvement in terms of facilitating uniform cooling of the entire coil 36. Further, the heat transfer member 90 is different from the configuration using a thin tube through which a refrigerant flows inside, and is a solid only and transfers heat to the object to be cooled, and there is room for improvement in terms of uniformly cooling the plurality of coils 36. . According to the present embodiment described above, any of these points to be improved can be improved.

  In the above description, the passive refrigerator 14 in which the second piston 78 is subordinately displaced according to the displacement of the first piston 74 has been described as the refrigerator 14. However, as a refrigerator, when the first piston 74 is reciprocally displaced, the second piston 78 side is displaced so that the second piston 78 is displaced at a phase shifted by 90 to 120 degrees of the phase of one cycle of the reciprocating displacement. A second drive source such as a linear motor for forcibly displacing can be provided on the phase controller 62 side. In this case, an active refrigerator is configured, and further energy saving can be achieved.

  In addition, a refrigerator other than the FPSC type can be used as the refrigerator 14. For example, when the restrictions on the installation space and weight of the refrigerator are loose, for example, the superconducting motor 10 is used as a power source for a large moving body such as a train or a ship, or as a power source for a machine whose installation position is fixed. In such a case, if the refrigerator has a plurality of thin tubes as described above and has a cooling performance capable of cooling to a very low temperature (for example, about 70 K), a refrigerator having a large physique can be used.

  In addition, as the refrigerator, a Stirling pulse tube refrigerator, a GM refrigerator, or the like each having a thin tube can be used. For example, in a pulse tube refrigerator, a pulse tube connected between the narrow tube 66 and the phase controller 62 is used in place of the second piston housing portion 70 described above. There is no piston inside the pulse tube. In this pulse tube refrigerator, a structure that vibrates the pressure by switching between valve opening and closing can also be used as the pressure vibration source 58. Further, as the GM refrigerator, the above-described FPSC type refrigerator, and the pressure vibration source 58 may be a rotary compressor or a structure that vibrates pressure by switching between valve opening and closing. In this structure, the phase controller 62 is omitted, and a displacer is provided as an expansion piston in a reciprocating manner in an expansion / compression section connected to the end of the narrow tube 66 opposite to the pressure vibration source 58. The displacer is moved back and forth by a motor such as a stepping motor during operation of the refrigerator, for example. As described above, in the present invention, various types of refrigerators can be used as long as the refrigerator has a thin tube through which a refrigerant flows.

[Second Embodiment]
FIG. 10 is a diagram showing a part of a thin tube and one superconducting coil fitted to the thin tube in the superconducting motor according to the second embodiment of the present invention. FIG. 11 is a view showing a state immediately before the thin tube is fitted to the superconducting coil of FIG.

  As shown in FIG. 10, in the present embodiment, the coil 36 is configured to have a substantially rectangular shape when viewed in the radial direction of the stator 22 (see FIG. 1). That is, the coil 36 includes plate portions 96 and 97 that are substantially parallel to each other, and a second plate portion 112 that is provided so as to be substantially orthogonal to both sides of each plate portion 96 and 97 and constitutes the coil end portion 46.

  Further, when the width dimension of the outer peripheral portion of the coil 36 is Bs, and the width dimension inside the straight portions 102 and 104 is Bc in the free state of the coil peripheral arrangement portion 100 of the narrow tube 66, Bs> Bc is satisfied. The dimensions of each part are regulated so as to satisfy. For this reason, the contact pressure and adhesion between the coil peripheral arrangement portion 100 and the coil 36 can be increased, and the narrow tube 66 can be fixed to the coil 36 more easily.

  Further, when the curvature radius inside the circular arc portion 108 which is provided in the coupling portion 106 of the thin tube 66 and has the smallest inner diameter in a free state is Rc1, by appropriately adjusting the curvature radius Rc1 of the circular arc portion 108, The thin tube 66 can be sufficiently brought into contact with the coil 36 while effectively preventing the destruction of the internal structure of the dense superconducting wire constituting the coil 36. In addition, the curvature radius Rc2 (FIG. 10) inside the circular arc portion 108 is larger than the curvature radius Rc1 (FIG. 11) in the free state in a state where the coil peripheral arrangement portion 100 is fitted to the outer peripheral portion of the coil 36. . Other configurations and operations are the same as those of the first embodiment shown in FIGS.

[Third Embodiment]
FIG. 12 is a view showing a part of a thin tube and one superconducting coil fitted to the thin tube in the superconducting motor according to the third embodiment of the present invention. FIG. 13 is a view showing a state immediately before the thin tube is fitted to the superconducting coil of FIG.

  In the present embodiment, in the second embodiment shown in FIGS. 10 to 11 described above, the connecting portion 106 of the coil surrounding arrangement portion 100 constituting the narrow tube is not an arc portion 108 (FIG. 7) but an elliptical portion. The whole is composed of a semi-elliptical portion 114 having a shape that is halved. Further, when the width dimension of the outer peripheral portion of the coil 36 is Bs, and the width dimension inside the straight portions 102 and 104 is Bc in the free state of the coil peripheral arrangement portion 100 of the narrow tube 66, Bs> Bc is satisfied. The dimensions of each part are regulated so as to satisfy.

  Further, in the free state of the coil peripheral arrangement portion 100, the linear direction of the straight portions 102, 104 between the top portion P (FIG. 13) inside the semi-elliptical portion 114 and one end of each of the straight portions 102, 104 (see FIG. By appropriately adjusting the length a1 with respect to the left and right direction of 13), it is possible to sufficiently bring the narrow tube 66 into contact with the coil 36 while effectively preventing the destruction of the internal structure of the dense superconducting wire constituting the coil 36. it can. Further, by providing a notch or the like which is a fine notch in the semi-elliptical part 114, it is possible to adjust the adhesion between the thin tube 66 and the coil 36 and the fixing strength. Other configurations and operations are the same as those of the first embodiment shown in FIG. 1 to FIG. 7 or the second embodiment shown in FIG. 10 to FIG. In addition, the connection part 106 can also be made into shapes other than the shape containing the circular arc part 108 (FIG. 6, 7, 10, 11) and the semi-elliptical part 114 (FIGS. 12, 13).

[Fourth Embodiment]
FIG. 14 is a view corresponding to FIG. 5, showing a superconducting motor according to a fourth embodiment of the present invention. In the case of the present embodiment, in the first embodiment shown in FIGS. 1 to 7 described above, the number of the thin tubes 66 is tripled, and the radial direction of the stator 22 is set for each outer peripheral portion of each coil 36. The three coil peripheral arrangement portions 100 are fitted so as to be separated with respect to each other (in the left-right direction in FIG. 14), and both ends of each coil peripheral arrangement portion 100 are connected to the regenerator 68 (FIG. And the second piston housing part 70 (see FIG. 1). According to such a configuration, the cooling performance for the coil 36 can be further improved. Other configurations and operations are the same as those in the first embodiment. In addition to the first embodiment, this embodiment is the same as the second embodiment shown in FIGS. 10 to 11 or the third embodiment shown in FIGS. It can also be combined.

[Fourth Embodiment]
FIG. 15 is a view corresponding to FIG. 5 and showing a superconducting motor according to a fifth embodiment of the present invention. In the case of the present embodiment, in the first embodiment shown in FIG. 1 to FIG. 7 described above, the coil peripheral arrangement portion 100 fitted to the outer peripheral portion of the coil 36 is Instead of the same position in the radial direction of the stator 22, the one-side straight portion 102 and the other-side straight portion 104 are in contact with different positions in the radial direction of the stator 22. For this reason, the width dimension Bs (see FIG. 7) between the outer surfaces of the plate parts 96 and 97, which is the width dimension of the outer peripheral part of the coil 36, is the free state of the substantially U-shaped coil peripheral arrangement part 100. The inner width dimension Bc (see FIG. 7) between the straight portions 102 and 104 is set to be equal to or smaller than Bs ≦ Bc.

  Moreover, after fitting the coil periphery arrangement | positioning part 100 to the outer peripheral part of the coil 36 so that each linear part 102,104 may be located on the virtual plane orthogonal to the winding axis O of the coil 36 with respect to the coil 36, The coil peripheral arrangement portion 100 is twisted and fixed to the outer peripheral portion of the coil 36 so that one position of each of the linear portions 102 and 104 is shifted so as to be inclined with respect to the winding axis O. Further, as shown in FIG. 15, only the other-side straight portion 104 of the straight portions 102 and 104 is sandwiched between the outer peripheral portions of the two coils 36 on both sides adjacent to each other in the circumferential direction. Is in contact with In other words, the configuration is such that two superconducting coils are cooled by one thin tube. Other configurations and operations are the same as those of the first embodiment shown in FIGS.

  In each of the above-described embodiments, the case where the present invention is applied to the structure of the inner rotor in which the stator is disposed to face the outer side in the radial direction of the rotor has been described. However, the present invention is not limited to this, and the present invention can also be applied to the structure of an outer rotor in which a stator is disposed opposite to the inner side in the radial direction of the rotor. In this case, the superconducting coil is wound around the outer peripheral end which is one end in the radial direction of the stator core.

  10 Superconducting motor, 12 Motor body, 14 Refrigerator, 16 Motor case, 18 Rotating shaft, 20 Rotor, 22 Stator, 24 Rotor core, 26 Permanent magnet, 28, 30 End plate, 32 Bearing, 34 Stator core, 36 Coil, 38 Back Yoke, 40 teeth, 42 slots, 44 slot arrangement part, 46 coil end part, 48 outer peripheral cylinder part, 50 inner cylinder member, 52 intermediate cylinder member, 54 first vacuum chamber, 56 second vacuum chamber, 58 pressure vibration source, 60 First Bracket, 62 Phase Controller, 64 Second Bracket, 66 Thin Tube, 68 Regenerator, 70 Second Piston Housing, 72 Cylinder, 74 First Piston, 76 Cylinder, 78 Second Piston, 82 Refrigerator, 84 Gas compressor, 86 regenerator, 88 bracket, 90 heat transfer member, 9 , 97 plate portion, 98 partial cylindrical section, 100 a coil surrounding arrangement unit, 102 one straight portion, 104 the other side straight portion, 106 connection portion, 108 arc portion, 110 insulator, 112 second plate portion, 114 semi-elliptical portion.

Claims (7)

A rotor arranged for rotation;
A stator disposed opposite to the rotor in the radial direction,
The stator includes a stator core and a plurality of superconducting coils composed of superconducting wires,
The stator core includes an annular back yoke, a plurality of teeth projecting radially at one end portion in the radial direction of the back yoke, and a slot provided between the teeth adjacent in the circumferential direction,
The plurality of superconducting coils are superconducting motors wound around the teeth,
Further comprising a refrigerator having at least one thin tube for flowing a low-temperature refrigerant inside;
The thin tube includes a coil surrounding arrangement portion arranged around the superconducting coil,
The coil peripheral arrangement part is provided in the thin tube, and along one outer peripheral part of the outer periphery of the superconducting coil that faces one side in the circumferential direction of the stator so as to go from one axial side of the stator to the other side. The other side of the outer periphery of the superconducting coil that faces the other side in the circumferential direction of the stator so as to go from the one side in the axial direction of the stator to the other side. An other side arrangement part arranged along the outer circumference part and in thermal contact with the other side outer circumference part, and a connecting part for connecting the one side arrangement part and the other side arrangement part on the same side in the axial direction of the stator. A superconducting motor characterized by comprising: The superconducting motor according to claim 1,
The one-side arrangement portion is arranged in the axial direction along the one-side outer peripheral portion of the outer peripheral portion of the superconducting coil facing the one-side circumferential direction of the stator,
The said other side arrangement | positioning part is arrange | positioned in the axial direction along the said other side outer peripheral part which faces the circumferential direction other side of the said stator among the outer peripheral parts of the said superconducting coil, The superconducting motor characterized by the above-mentioned. The superconducting motor according to claim 1 or 2,
The superconducting motor according to claim 1, wherein the coil peripheral arrangement portion is fitted to an outer peripheral portion of the superconducting coil. In the superconducting motor according to claim 3,
The superconducting motor according to claim 1, wherein the coil peripheral arrangement portion is fitted to an outer peripheral portion of the superconducting coil so as to go from one side of the stator in the axial direction to the other side. In the superconducting motor according to any one of claims 1 to 4,
An arc portion provided in the connecting portion and having the smallest radius of curvature in the free state is located at the other axial end portion of the stator in the free state and opposed to the arc portion in the outer peripheral portion of the superconducting coil. A superconducting motor having an inner radius of curvature Rc smaller than the radius of curvature Rs of the portion. In the superconducting motor according to any one of claims 1 to 5,
The inner width dimension Bc between the one-side arrangement part and the other-side arrangement part in the free state of the coil peripheral arrangement part is smaller than the width dimension Bs between the one-side outer periphery part and the other-side outer periphery part of the superconducting coil. A superconducting motor characterized by The superconducting motor according to any one of claims 1 to 6,
The superconducting motor according to claim 1, wherein the coil peripheral arrangement part is joined to an outer peripheral part of the superconducting coil by a high thermal conductive adhesive.

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