JP2818109B2 - Superconducting rotating electric machine rotor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotor of a superconducting rotary electric machine, and more particularly to a structure of a helium reservoir for holding liquid helium as a refrigerant of a superconducting field coil.

[0002]

2. Description of the Related Art FIGS.
FIG. 9 is a cross-sectional view showing a rotor of the conventional superconducting rotary electric machine shown in the microfilm of No. 587, FIG.
FIG. 10 is a sectional view taken along line XX in FIG. In the figure, reference numeral 1 denotes a hollow torque tube, which comprises a coil mounting part 2 and a torque transmitting part 3. A slot groove 20 is provided in the outer peripheral portion of the coil mounting portion 2, the superconducting field coil 4 is housed, a helium outer cylinder 7 is fitted on the outer periphery, and a low-temperature damper 6 is fitted on the outer side. Have been. A normal-temperature damper 5 having the same length as the torque tube 1 is disposed concentrically with the torque tube 1 on the outer periphery of the low-temperature damper 6, and both ends of the torque transmission unit 3 and the normal-temperature damper 5 are connected to a drive-side end shaft 9. And the other end shaft 10 is connected to the bearing 1.
It is supported at 1. A slip ring 12 is provided on the non-drive side end shaft 10 so as to supply a field current to the superconducting field coil 4. Helium end plates 8 are mounted on both ends of the coil mounting portion 2, a heat exchanger 13 is provided on the outer periphery of the torque transmitting portion 3, and a side radiation shield 14 is provided on the inner side. The space 15 is a vacuum section for heat shielding, and 16 is a helium liquid storage section.

In the rotor configured as described above, the superconducting field coil 4 disposed in the coil mounting portion 2 is cooled to a very low temperature, for example, 4.2 K, so that a superconducting state is established and a current flows. As a result, a magnetic field is generated in the superconducting field coil 4, and an AC power is generated in a stator (not shown). In order to cool the superconducting field coil 4 and keep it at a very low temperature, liquid helium, which is a refrigerant, is introduced from the central part of the non-drive end shaft 10 through an introduction pipe (not shown), and a helium outer cylinder 7 and a helium end plate. The inside of the rotor is thermally shielded by a vacuum unit 15 while being supplied to the liquid helium storage unit formed by 8. Further, the amount of heat flowing into the cryogenic portion via the torque transmitting portion 3 is limited by forming the torque transmitting portion 3 for transmitting the torque to the coil mounting portion 2 into a thin cylindrical shape and providing the heat exchanger 13. Further, a side radiation shield 14 is provided to reduce heat radiation from the axial side surface. The normal temperature damper 5 functions as a vacuum outer cylinder, and the low temperature damper 6 functions as a radiation shield to the helium storage unit. Further, they function to shield the harmonic magnetic field from the stator to protect the superconducting field coil 4 and to suppress the vibration of the rotor due to the disturbance of the power system. The heat transfer disk 17 provided in the helium reservoir 16 is different from the coil mounting portion 2 in that copper, copper alloy, aluminum,
It is made of a material having high thermal conductivity such as aluminum alloy or titanium and has a hollow hole 17a, and is mounted on the inner wall of the hollow portion of the coil mounting portion 2 so as to be orthogonal to the axial direction of the rotor.

FIGS. 11 and 12 show another conventional example.
The relationship between the figures is the same as in FIGS. 9 and 10. Reference numeral 18 denotes a heat transfer rectangular plate, which is made of a material having a high thermal conductivity as in the conventional example described above, and is radially attached to the inner wall of the helium liquid reservoir 16 in parallel with the rotor axis. Note that, similarly to FIG. 9, in FIG. 11, the helium introduction / discharge device connected to the piping and the helium introduction / discharge system inside the rotor is omitted.

In the conventional rotor configured as described above, the superconducting field coil 4 generally uses a superconducting wire of a niobium-titanium alloy. The critical current of the superconducting field coil 4 using a niobium-titanium alloy decreases with an increase in temperature. When the temperature rises from 4.2K by 1K, the critical current decreases by about 40%. In order to prevent the critical current of the superconducting field coil 4 from decreasing and to prevent the occurrence of the normal conducting state, it is necessary to avoid the temperature rise of the liquid helium near the superconducting field coil 4. However, since liquid helium has a low thermal conductivity, the temperature increases as the distance from the center of rotation increases due to adiabatic compression due to centrifugal force accompanying rotation of the rotor.

The outer liquid helium whose temperature has increased due to the adiabatic compression exchanges heat with the inner liquid helium by the heat transfer of the heat transfer disk 17 or the heat transfer rectangular plate 18. FIG.
In this case, the temperature rise ΔT of the outer liquid helium with respect to the inner liquid helium of the heat transfer disk 17 is ΔT = (Q / 2πλ) · log (Do / Di) / (nt) where Q = heat transfer circle Heat transfer amount of plate λ = Thermal conductivity of heat transfer disk Do = Outer diameter of heat transfer disk Di = Inner diameter of heat transfer disk n = Number of heat transfer disks t = Thickness of heat transfer disk It is. By appropriately selecting the material and number of the heat transfer disks 17 and the thickness thereof, the temperature rise of the outer liquid helium with respect to the inner liquid helium can be made within an allowable range. The same applies to the case where the heat transfer rectangular plate 18 is used. Thus, the heat transfer disk 17 and the heat transfer rectangular plate 18 function as heat transfer members for making the temperature distribution of liquid helium uniform.

[0007]

The rotor of the conventional superconducting rotary electric machine has different thermal expansion coefficients because the materials of the coil mounting portion and the heat transfer member are different. As a result, a difference occurs in the amount of heat shrinkage due to cooling with liquid helium, and stress is generated at the joint between the coil attachment portion and the heat transfer member. In the worst case, the joint between the coil attachment portion and the heat transfer member is broken. There was a problem that. In addition, when a disc-shaped heat transfer member is used, it is difficult to uniformly distribute the liquid helium in the helium liquid reservoir in the axial direction, and there is a problem in that a bias occurs and uniform cooling cannot be performed. . In addition, when the heat transfer member is mounted on the coil mounting portion by welding, the welding operation is difficult because the hollow portion of the coil mounting portion is narrow and long. Further, since the heat transfer member and the coil mounting portion are made of different materials, welding is difficult and welding defects are easily generated, and the reliability of the joint between the heat transfer member and the coil mounting portion is low. Was.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and reduces the stress generated at the joint between the coil attachment portion and the heat transfer member, thereby reducing the stress between the coil attachment portion and the heat transfer member. An object of the present invention is to obtain a highly reliable rotor of a superconducting rotating electric machine in which a joint is not broken. It is another object of the present invention to obtain a highly reliable rotor of a superconducting rotary electric machine having good cooling characteristics by uniformly distributing liquid helium even when a disk-shaped heat transfer member is used.

[0009]

In the rotor of the superconducting rotary electric machine according to the present invention, the heat transfer member has a divided structure in order to reduce the thermal stress generated at the joint between the coil mounting portion and the heat transfer member. Things. In addition, the rotor of the superconducting rotary electric machine according to the present invention is configured such that the heat transfer member is made of a material having the same coefficient of thermal expansion as that of the coil attachment portion in order to reduce thermal stress generated in a joint portion between the coil attachment portion and the heat transfer member. It is what it was. Further, the rotor of the superconducting rotary electric machine according to the present invention has a portion in contact with the coil mounting portion hollow portion peripheral wall of the disc-shaped heat transfer member in order to uniformly distribute the liquid helium in the axial direction and eliminate variations in cooling temperature. A notch is provided in a part of the liquid helium so that the liquid helium reservoirs separated by the heat transfer member communicate with each other. Still further, in the rotor of the superconducting rotary electric machine according to the present invention, the heat transfer member is fixed to the mounting hole formed in the coil mounting portion by fastening means.

[0010]

According to the present invention, the rotor of the superconducting rotating electric machine is:
By dividing the heat transfer member, the absolute amount of the difference in the amount of contraction between the heat transfer member and the coil mounting portion is reduced, and the thermal stress generated at the joint is reduced. In addition, the rotor of the superconducting rotary electric machine according to the present invention has a heat transfer member made of a material having the same coefficient of thermal expansion as the coil attachment portion, thereby eliminating the difference in the amount of contraction between the heat transfer member and the coil attachment portion. Also, no stress is generated at the joint between the heat transfer member and the coil mounting portion.
Further, in the rotor of the superconducting rotary electric machine according to the present invention, liquid helium moves in the axial direction of the coil mounting portion by cutting out a part of the disk-shaped heat transfer member which is in contact with the peripheral wall of the hollow portion of the coil mounting portion. And the bias of liquid helium is prevented, and the cooling temperature of the coil mounting portion does not vary. Furthermore, in the rotor of the superconducting rotary electric machine according to the present invention, since the heat transfer member is fixed to the mounting hole perforated in the coil mounting portion by the fastening means, the reliability of the coupling portion between the heat transfer member and the coil mounting portion is improved. Can be

[0011]

[Embodiment 1] A first embodiment of the present invention will be described with reference to the drawings. 1 and 2 are views for explaining a first embodiment of the present invention. FIG. 1 is an axial sectional view, and FIG.
It is arrow sectional drawing along a line. Among the reference numerals in the drawings, those which are the same as those in FIGS. 9 to 12 are the same or corresponding, and the description thereof will be omitted. Further, the functions of supplying liquid helium as a refrigerant and generating an AC power by generating a magnetic field are the same as those of the conventional example, and thus description thereof will be omitted. In the figure, a heat transfer disc 100 is attached to the helium reservoir 16 on the peripheral wall of the hollow portion of the coil mounting portion 2 at right angles to the axial direction of the coil mounting portion 2. The heat transfer disk 100, which is a heat transfer member, is divided into a plurality of pieces in the circumferential direction. The heat transfer disc 100 has a hollow 100a and a cutout 100b in a part of the coil mounting portion 2 that is in contact with the peripheral wall of the hollow.

The liquid helium can move in the axial direction of the coil mounting portion 2 through the notch 100b provided in the heat transfer disk 100. For this reason, the liquid helium is not biased in the axial direction of the coil mounting portion 2, and the coil mounting portion 2 can be cooled uniformly. Heat transfer disk 1
00 is a divided structure, the stress generated at the joint between the heat transfer disk 100 and the coil mounting portion 2 is lower than that of the rotor of the conventional superconducting rotating electric machine, and the heat transfer disk 100 and the coil mounting portion 2 A highly reliable rotor of the superconducting rotating electric machine having a joint portion with the rotor can be obtained. The heat transfer disk 100 can be divided into two or more arbitrary arbitrary numbers in the circumferential direction.

Embodiment 2 FIG. A second embodiment of the present invention will be described with reference to the drawings. FIG.
FIG. 4 and FIG. 4 are for explaining the second embodiment of the present invention, and the relation of the drawings is the same as that of FIG. 1 and FIG. In the figure, a heat transfer rectangular plate 200 is attached to the helium reservoir 16 on the peripheral wall of the hollow portion of the coil attachment portion 2 in the axial direction of the rotor. Then, a heat transfer rectangular plate 200 as a heat transfer member
Is divided into a plurality in the axial direction. The length in the axial direction is preferably obtained by equally dividing the entire length of the coil mounting portion 2 so that the difference in the amount of shrinkage due to cooling becomes uniform.

The heat transfer rectangular plate 18 cooled by liquid helium and the coil mounting portion 2 have different coefficients of thermal expansion, so that a difference occurs in the amount of contraction. This difference in the amount of shrinkage is caused by the heat transfer rectangular plate 20.
0 is proportional to the length of the coupling portion between the coil mounting portion 2 and 0. Since the heat transfer rectangular plate 200 is divided into a plurality of parts in the axial direction of the coil mounting part 2, the difference in the amount of shrinkage from the coil mounting part 2 is several minutes smaller than that of a conventional superconducting rotary electric machine. It becomes 1.
The difference in the amount of shrinkage between the heat transfer rectangular plate 200 and the coil mounting portion 2 is proportional to the stress generated at the joint between the heat transfer rectangular plate 200 and the coil mounting portion 2. The stress generated in the fastening portion between the heat transfer rectangular plate 200 and the coil mounting portion 2 is reduced to a fraction of that in the conventional superconducting rotary electric machine. By appropriately selecting the number of divisions of the heat transfer rectangular plate 200, there is no possibility that the joint between the heat transfer rectangular plate 200 and the coil mounting portion 2 will be broken, and a highly reliable rotor of the superconducting rotary electric machine can be obtained. .

Embodiment 3 FIG. A third embodiment of the present invention will be described. In the third embodiment, the heat transfer disk 10 according to the first embodiment described above is used.
0 is a material having the same thermal expansion coefficient as that of the coil mounting portion 2. The same applies to the heat transfer rectangular plate 200 in the second embodiment.

Since the heat transfer disk 100 or the rectangular heat transfer plate 200 cooled by liquid helium and the coil mounting portion 2 have the same coefficient of thermal expansion, there is no difference in the amount of contraction. Alternatively, since no thermal stress is generated at the joint between the heat transfer rectangular plate 200 and the coil mounting portion 2, the joint is not broken. Therefore, a highly reliable rotor of the superconducting rotating electric machine can be obtained.

Embodiment 4 FIG. A fourth embodiment of the present invention will be described with reference to the drawings. FIGS. 5 and 6 are for explaining the fourth embodiment of the present invention, and the relation of the drawings is the same as that of FIGS. 1 and 2. FIG. In the figure, a heat transfer disk 100 provided in a helium reservoir 16 is provided.
Are fastened by bolts 102 from mounting holes 101 provided at the bottom of a slot groove 20 for inserting the superconducting field coil 4 provided in the coil mounting portion 2.

In the rotor constructed as in the present invention, since the coil mounting portion 2 and the heat transfer disk 100 are fastened by the bolts 102, the coil mounting portion 2 and the heat transfer disk 100 are of different types. Even if the material is used, a defect does not occur in the joint portion, the joining operation between the coil attaching portion 2 and the heat transfer disk 100 is easy, and the highly reliable superconducting portion of the joint portion between the coil attaching portion 2 and the heat transfer disk 100 is provided. A rotor for a rotating electric machine can be obtained. In the above description, the heat transfer disk 100 is provided with the mounting hole 101 at the bottom of the slot groove 20. However, the heat transfer disk 100 is fastened by bolts from a position other than the slot groove bottom of the coil mounting portion. Has the same effect. Of course, the mounting hole 101 may be provided at a predetermined depth from the inner diameter side of the hollow portion.
Further, a heat transfer rectangular plate 200 as shown in FIGS.
May be fixed to the coil mounting portion by similar means.

Embodiment 5 FIG. A fifth embodiment of the present invention will be described with reference to the drawings. FIGS. 7 and 8 are for explaining the fifth embodiment of the present invention, and the relation of the figures is the same as that of FIGS. The heat transfer disk 100 in the figure is provided in the same manner as in FIGS. 1 and 2 described above. The heat transfer rectangular plate 200 is provided in the same manner as in FIGS. 3 and 4 described above.

The liquid helium can move in the axial direction of the coil mounting portion 2 through the notch 100b provided in the heat transfer disk 100. Therefore, the liquid helium is not biased in the axial direction of the coil mounting portion 2, and the coil mounting portion 2 can be cooled uniformly. Further, since the helium reservoir can be subdivided by the heat transfer disk 100 and the heat transfer rectangular plate 200, the stirring of the liquid helium during the low-speed rotation of the rotor can be suppressed, and the effect of suppressing the consumption of the liquid helium can be reduced. is there. Further, since the heat transfer disk 100 and the heat transfer rectangular plate 200 have a divided structure, the stress generated at the joint with the coil mounting portion 2 is lower than that of the rotor of the conventional superconducting rotating electric machine, and the joint is broken. Therefore, a highly reliable rotor of the superconducting rotating electric machine can be obtained.

[0021]

As described above, claims 1 to 3 are as described above.
In the rotor of the superconducting rotary electric machine according to any one of the inventions, the heat transfer member is divided in the circumferential direction or the axial direction, so that the absolute amount of the difference in the amount of contraction between the heat transfer member and the coil mounting portion is reduced, Is reduced, and the joint between the coil mounting portion and the heat transfer member is not broken.

The rotor of the superconducting rotary electric machine according to the third aspect of the present invention is characterized in that the rotor of the superconducting rotary electric machine is connected to the peripheral wall at a plurality of locations in the axial direction inside the helium reservoir, Is connected to the peripheral wall with a width in the radial direction of the rotor, is disposed parallel to the rotor axis, and substantially equally divides the length of the helium reservoir into a plurality in the rotor axis direction. With a plurality of rectangular heat transfer members divided into unit lengths, the helium liquid reservoir can be subdivided, liquid helium agitation during low-speed rotation of the rotor can be suppressed, and liquid helium consumption can be reduced. The amount can be reduced.

Further, in the rotor of the superconducting rotary electric machine according to the fourth aspect of the present invention, since the heat transfer member is made of a material having the same coefficient of thermal expansion as that of the coil attachment portion, the amount of heat shrinkage between the heat transfer member and the coil attachment portion is reduced. The difference is eliminated and the occurrence of stress due to heat shrinkage is prevented,
The joint between the coil mounting portion and the heat transfer member is not broken.

According to a fifth aspect of the present invention, there is provided a rotor for a superconducting rotary electric machine, wherein a heat transfer member mounted at right angles to an axial direction of a coil mounting portion is divided into a plurality of portions in a circumferential direction, and a hollow portion of the coil mounting portion is provided. Since a partial notch is provided in contact with the peripheral wall,
The liquid helium moves in the axial direction of the coil mounting portion, so that the liquid helium is not biased and the coil mounting portion is uniformly cooled.

Further, in the rotor of the superconducting rotary electric machine according to the present invention, since the heat transfer member is fixed to the mounting hole formed in the coil mounting portion by the fastening means, the material of the heat transfer member and the coil mounting portion is not limited. Even if they are different, the joint is not broken.

[Brief description of the drawings]

FIG. 1 is an axial sectional view of a rotor of a superconducting rotary electric machine according to a first embodiment of the present invention.

FIG. 2 shows a first embodiment of the present invention.
It is arrow sectional drawing along a line.

FIG. 3 is an axial sectional view of a rotor of a superconducting rotary electric machine according to a second embodiment of the present invention.

FIG. 4 shows a second embodiment of the present invention.
It is arrow sectional drawing along a line.

FIG. 5 is an axial sectional view of a rotor of a superconducting rotary electric machine according to a fourth embodiment of the present invention.

FIG. 6 shows a fourth embodiment of the present invention.
It is arrow sectional drawing along a line.

FIG. 7 is an axial sectional view of a rotor of a superconducting rotary electric machine according to a fifth embodiment of the present invention.

FIG. 8 is a sectional view taken along line XX of FIG. 7 showing a fifth embodiment of the present invention;
It is arrow sectional drawing along a line.

FIG. 9 is an axial sectional view of a rotor of a conventional superconducting rotary electric machine.

FIG. 10 is a sectional view taken along the line XX of FIG. 9;

FIG. 11 is an axial sectional view of a rotor of a conventional superconducting rotary electric machine.

12 is a sectional view taken along the line XX in FIG. 11;

[Explanation of symbols]

2 Coil mounting part, 4 superconducting field coil, 16 helium reservoir, 17 heat transfer disk, 18 heat transfer rectangular plate, 20
Slot groove, 100 heat transfer disk, 100a hollow hole, 1
00b notch, 101 mounting hole, 102 bolt, 2
00 Heat transfer rectangular plate.

Claims (6)

(57) [Claims] 1. A hollow cylindrical member having a superconducting field coil supported on an outer peripheral portion thereof, a helium reservoir formed in a hollow portion, and a peripheral wall formed at a plurality of axial positions inside the helium reservoir. In a rotor of a superconducting rotary electric machine having a coil mounting portion provided with a heat transfer member of a perforated disk coupled to a rotating member of the superconducting rotary electric machine, the heat transfer member is divided in a circumferential direction. Child. 2. A hollow cylindrical shape having a superconducting field coil supported on an outer peripheral portion thereof, a helium liquid reservoir formed in the hollow portion, and a helium liquid reservoir formed inside the helium liquid reservoir in an axial direction thereof. In a rotor of a superconducting rotary electric machine having a coil mounting portion having a plurality of rectangular heat transfer members having a width in a radial direction and being connected to a peripheral wall and disposed in parallel with a rotor axis, the heat transfer member rotates. A rotor for a superconducting rotary electric machine, wherein the rotor is divided into unit lengths in which a length of the helium reservoir is substantially equally divided into a plurality in a child axis direction. 3. A coil having a hollow cylindrical shape and supporting a superconducting field coil at an outer peripheral portion thereof, a helium liquid reservoir formed in the hollow portion, and a heat transfer member provided inside the helium liquid reservoir. In a rotor of a superconducting rotary electric machine having a mounting portion, a heat transfer member of a perforated disk which is coupled to a peripheral wall at a plurality of axial directions inside the helium reservoir and divided in the circumferential direction , and a radius of the rotor Is attached to the peripheral wall with a width in the direction and is disposed in parallel with the rotor axis and rotates
A superconducting rotary electric machine having a coil mounting portion provided with a plurality of rectangular heat transfer members divided into unit lengths which substantially divide the length of the helium liquid reservoir portion into a plurality in the child axis direction. Rotor. 4. The rotor of a superconducting rotary electric machine according to claim 1, wherein the heat transfer member is made of a material having the same coefficient of thermal expansion as the coil mounting portion. 5. A rotor for a superconducting rotary electric machine according to claim 1, wherein a notch is provided on an outer periphery of said perforated heat transfer member. 6. A rotor for a superconducting rotary electric machine according to claim 1, wherein said heat transfer member is fixed to a mounting hole formed in a coil mounting portion by fastening means.