JPS61137692A - Production of radiation shield in rotor of superconduction rotary electric machine - Google Patents

Abstract

PURPOSE:To obtain with high reliability the radiation shield with the duct groove for cooling by the explosive bonding of shielding bodies each other by interposing a low melting point metal bar between the radiation shielding bodies of cylindrical inner and outer two layers. CONSTITUTION:Cylindrical radiation shielding bodies 14a, 14b becoming the inner and outer layers are inserted into the core bar 18 for explosive bonding with co-axial arrangement. A low melting point metal bar 19 is arranged in the axial direction in the gap between the shielding bodies 14a, 14b and the outer peripheral part of the shielding body 14b is covered by the surrounding body and a gun powder 20 is ignited and exploded with charging it therein. Both parts of the shielding bodies 14a, 14b are deformed and bond3d explosively utilizing the pressure at this explosive time and the volume of the low melting point metal 19. Then the bonded part is heated to melt and flow out the low melting point metal 19 so as to from the duct groove 16 for cooling on this part.

Description

Detailed Description of the Invention (Technical Field of the Invention) The present invention relates to a rotor for a superconducting rotating electrical machine, in which the rotor is removed from the rotor outer cylinder provided in a gap between the rotor inner cylinder and the rotor outer cylinder. The present invention relates to a method for manufacturing a radiation shield for a rotor of a superconducting rotating electric machine, which allows a radiation shield having a cylindrical inner and outer two-layer structure for preventing heat infiltration into an inner cylinder to be easily and inexpensively manufactured with high reliability.

[Technical background of the invention and its problems]

6 and 7 show the structure of a rotor of a typical conventional superconducting generator. That is, in FIGS. 6 and 7, 2 has liquid helium 1 inside as a cooling medium.
3 is a rotor outer cylinder provided concentrically with a predetermined gap outside this rotor inner cylinder fFi2, and these are provided at both ends of the rotor inner cylinder 2. They are integrally connected via a torque tube 4. in this case,
One end of the rotor inner cylinder 2 and the rotor outer cylinder 3 is firmly attached to the end of the torque tube 4 with bolts, and the other end is a thermal expansion/contraction absorber that absorbs thermal loincloth at the end of the torque tube 4. They are connected via a body 5. In addition, the rotor outer cylinder 3 also functions as a vacuum container and includes a room temperature damper 3a and inner and outer reinforcing rings 3b to prevent penetration of the alternating current magnetic field.
, 3c. 6 is the rotor inner cylinder 2 from the shaft end
8 is a rotating double tube for supplying rheum 1 to a liquid provided in communication with the inside of the rotor, and 8 is a coil groove 7 of the rotor inner cylinder 2.
This superconducting coil 8 is firmly fixed against centrifugal force and electromagnetic force using a wedge 9 and an insulator 10. Reference numeral 11 denotes an end portion of the superconducting coil 8 led out from the rotor inner cylinder 2;
1 is firmly fixed using a retaining ring 12 against centrifugal force and electromagnetic force. Further, reference numeral 13 denotes a joint shaft that is firmly connected to both ends of the rotor outer cylinder 3 via bolts or the like. Furthermore, 14 is a radiation shield provided in the gap existing between the rotor outer cylinder 3 and the rotor inner cylinder 2 and mounted on the torque tube 4 via a seat 15, and this radiation shield 14 is kept at room temperature. The inside of the rotor I, which is at the liquid helium temperature from the rotor outer cylinder 3! This prevents heat from entering I2.

By the way, in the rotor of the superconducting generator configured as described above, the radiation shield 14 provided in the gap existing between the rotor outer cylinder 3 and the rotor inner cylinder 2 is at an intermediate temperature between normal temperature and liquid helium temperature. It is necessary to maintain the temperature of the torque tube at an appropriate temperature, and as shown in Fig. 9, a material with good thermal conductivity (e.g., AI, Cu, etc.) is used in the case of a small-capacity forming machine. Cooled by heat conduction.

However, in large-capacity machines, the electromagnetic force and centrifugal force that act on the radiation shield in the event of an accident become large, so the radiation shield should be made of as high-strength material as possible, and the diameter of the rotor outer cylinder 3 should be prevented from increasing. Therefore, it needs to be thin.

Generally, high-strength materials have poor thermal conductivity, so the radiation shield is constructed with two inner and outer layers of cylindrical thin-walled radiation shields 14a and 14b, as shown in FIG. It has been considered to form cooling guide grooves 16 in one or both of them by machining for sealing or flowing cooling gas. However, in order to manufacture a radiation shield with such a configuration, for example, when considering a 10100O class superconducting generator, the diameter must be Φ800 to 10001r.
IIR length is 4000~5000m+, wall thickness is 10~
The inner and outer layers of the cylindrical radiation shield bodies 14a and 14b are integrated using liquid smoke or the like to form a two-layer structure, and a plurality of cooling guides 16 are machined in the axial direction between the layers. Since it has to be processed, it has the disadvantage that deformation occurs during processing, making it extremely difficult. In addition, cylindrical radiation shield bodies 14a and 14 serving as inner and outer layers
Since b is thin-walled, it has the disadvantage that it is difficult to integrate it with liquid smoke or the like.

(Object of the Invention) The present invention has been made to solve the above-mentioned drawbacks, and its purpose is to connect the rotor outer cylinder to the rotor inner cylinder provided in the gap between the rotor inner cylinder and the rotor outer cylinder. To provide a method for manufacturing a radiation shield for a rotor of a superconducting rotating electric machine, which can easily and inexpensively manufacture a radiation shield having a cylindrical inner and outer two-layer structure for preventing heat infiltration into the rotor with high reliability. There is a particular thing.

[Summary of the invention]

In order to achieve such an object, the present invention has two cylindrical inner and outer cylinders provided in the gap between the rotor inner cylinder and the rotor outer cylinder.
In manufacturing a radiation shield with a layered structure, an explosion core is inserted into the hollow part of a radiation shield body that is an inner layer that is provided concentrically with a radiation shield body that is an outer layer, and these inner layers,
A plurality of filamentous low melting point metal strips are arranged in the gap between the radiation shield bodies serving as the outer layer to form guide grooves for the cold part, and the outer periphery of the radiation shield body serving as the outer layer is covered with explosives. By exploding this gunpowder, the pressure at the time of the explosion is used to cause the radiation shielding body serving as the outer layer to explode into contact with the radiation shielding body serving as the inner layer, and then by heating, the low melting point metal of the filament is melted. This feature is characterized in that a cooling duct groove is formed in this portion to allow the water to flow out.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1(a) shows a configuration example for explaining the method of manufacturing a radiation shield according to the present invention.

In FIG. 1(a), reference numeral 18 denotes a cylindrical core metal having a plurality of grooves 17 extending in the axial direction on its outer peripheral surface, and a cylindrical thin-walled radiation shield body 14a serving as an inner and outer layer of the core metal 18, 14
Insert b concentrically.

Next, in the gap existing between the radiation shielding body 14b serving as the outer layer and the radiation shielding body 14a serving as the inner layer, a low melting point metal 19 is arranged in the axial direction in correspondence with the groove 17 in the mandrel 18. . Further, the outer periphery of the radiation shield body 14b serving as the outer layer is covered with a surrounding material, and the gunpowder 20 is filled in the surrounding material.

In this state, when fire #20 is ignited and exploded, the inner and outer layers of the cylindrical thin radiation shield bodies 14a and 14b are created.
At the same time, the inner layer radiation shield 14a is deformed inwardly along the groove 17 of the mandrel 18 due to the pressure at the time of the explosion. In this case, one low melting point metal becomes an inner layer in the groove 17 of the core metal 18 due to the pressure at the time of explosion bonding in the radiation shield body 14a.
By deforming and entering the cylindrical thin radiation shield bodies 14a and 14b, which become the inner and outer layers, are integrated.

Thereafter, the low melting point metal 19 is melted by heating and flows out to the outside, thereby forming the cooling duct groove 16 in this portion.

As described above, according to the method of manufacturing the radiation shield according to the above embodiment, by increasing the rigidity of the mandrel 18, the inner diameter of the radiation shield can be adjusted as shown in FIG. It can be seen that although the pressure at the time is insufficient and the diameter changes by about 0.5% to 1% with respect to the center, the center shows a uniform deformation state.

For example, if the diameter is Φ1000ffl, this value is 5111
This means that there is a diameter change of 11 to 10 m+, which is not a small value when viewed as a rotating body in a high centrifugal force field.

However, if each end portion is cut by about 10%, the outer diameter is 0.05% or less, which is well within the allowable value.

In addition, as shown in Figure 3, when the results of a long-sonic deep damage test conducted from the outer circumferential surface after explosive bonding are developed in the circumferential direction, the hatched areas in the figure indicate non-bonded areas. It was found from this that the length of this non-adhesive part is limited to about 3% of the total length on each of the detonation side and the radiation detonation side. The other parts showed a completely good adhesion state.

Therefore, by only cutting off about 10% of both ends, a radiation shield with good dimensions and good adhesion can be obtained.
Duct groove 16 for good cooling by melting 9
can be formed.

FIG. 1(b) is an enlarged sectional view showing an exaggerated cooling duct groove according to the method of this embodiment.

Next, a method of manufacturing a radiation shield according to another embodiment of the present invention will be described.

In FIG. 4(a), a grooveless metal core 18 is used, and a thin cylindrical radiation shield body 148 serves as the inner and outer layers.
．． Using the volume of the low melting point metal 19 disposed in the gap between the inner and outer layers 148 and 14b, pressure is applied so that both the inner and outer layers of the cylindrical thin radiation shield body 148 and 14b are deformed at the time of explosion. A radiation shield is manufactured by forming cooling duct grooves 16 as shown in FIG. 4(b).

Further, as shown in FIG. 5(a), the radiation shield body 14b serving as the outer layer and the radiation shield body 14a serving as the inner layer are arranged concentrically and inserted into the cylindrical explosion core 18. A plurality of linear low-melting point metals 19 are arranged in the axial direction to form cooling guide grooves 16 in the gaps existing between the two, and the inner peripheral part of the radiation shield body 14a serving as the inner layer is covered with a surrounding material. The gunpowder 20 is then filled in it. In this case, the low melting point metal 19 is covered with a coating to prevent it from melting due to the heat of the explosion. Therefore, in such a state, 20 gunpowder
By detonating the metal, the radiation shield body 14b serving as the outer layer and the radiation shield body 14a serving as the inner layer are explosively bonded using the pressure at the time of the explosion, and at the same time, the filamentous low melting point metal 20 is used as shown in FIG. A cooling duct groove 16 as shown in b) can be formed.

It goes without saying that this pond water invention can be practiced as appropriate without changing its gist.

〔Effect of the invention〕

As described above, according to the present invention, a cylindrical tube is provided in the gap between the rotor inner cylinder and the rotor outer cylinder to prevent heat from penetrating from the rotor outer cylinder to the rotor inner cylinder. It is possible to provide a method for manufacturing a radiation shield for a rotor of a superconducting rotary N machine, which allows a radiation shield having a two-layer structure, an inner layer and an outer layer, to be manufactured easily and inexpensively with high reliability.

[Brief explanation of the drawing]

FIG. 1 is a configuration explanatory diagram showing an embodiment of a method for manufacturing a radiation shield in a rotor of a superconducting rotating electric machine according to the present invention;
Figure 2 is a diagram showing the dimensional change of the radiation shield after explosion bonding obtained by the method of the same example, Figure 3 is a diagram showing the ultrasonic flaw detection test results of the width-divided shield after explosion bonding, and Figure 4 Figures 6 and 5 are explanatory configuration diagrams showing embodiments of the pond of the present invention, respectively, and Figures 6 and 7 are representative configuration examples of the rotor of a conventional superconducting rotating electric machine. is a longitudinal section,
Is Figure 7 an arrow along line A-A in Figure 6? J! Sectional view, No. 8
This figure is a diagram showing the temperature distribution of the torque tube to which the radiation shield shown in FIG. 6 is attached, and FIG. 9 is a perspective view showing the structure of the radiation shield. DESCRIPTION OF SYMBOLS 1...Liquid helium, 2...Rotor inner cylinder, 3...Rotor outer cylinder, 3a...Normal temperature damper, 3b. 3C... Reinforcement ring along the inside and outside, 4...
... Torque tube, 5 ... Heat expansion and contraction absorber,
6...Rotating 2-drop tube, 7...Rotor coil groove, 9...Rotor wedge, 10...
Insulating spacer, 11... Coil end part, 12
・・・・・・Help ring, 13・・・・Joint shaft,
14...Radiation shield, 14a, 14b...
...inner layer. Outer radiation shield body, 15...Radiation shield mounting seat, 16...Cooling dug 1-groove, 17...
... Core metal groove, 18... Core metal groove, 19...
...Low melting point metal, 20...Explosive powder. Applicant's representative Patent attorney Takehiko Suzue (a) Figure 1 Figure 2 Figure 3 Figure 4 (a)

Claims (2)

[Claims] (1) Gap between the rotor inner cylinder that houses the cooling medium therein and the rotor outer cylinder that is provided with a room temperature damper that is concentrically provided with a predetermined gap outside the rotor inner cylinder. Manufacturing a radiation shield for a rotor of a superconducting rotating electric machine, which is provided in a rotor and has a cylindrical inner and outer two-layer structure for preventing heat infiltration from the rotor outer cylinder to the rotor inner cylinder. In this method, an explosion core is inserted into the hollow part of the radiation shield body, which is the inner layer, which is provided concentrically with the radiation shield body, which is the outer layer, and is cooled in the gap between the inner layer and the radiation shield body, which is the outer layer. A plurality of low melting point metal strips are arranged to form guide grooves for the radiation shield, and the outer periphery of the radiation shield body is covered with gunpowder. The radiation shielding body serving as the outer layer and the radiation shielding body serving as the inner layer are explosively bonded to each other using the heating method, and then heated to melt and flow out the low melting point metal of the filaments to form a cooling duct groove in this portion. A method for manufacturing a radiation shield in a rotor of a superconducting rotating electrical machine, characterized by: (2) Existing between the rotor inner cylinder that houses the cooling medium therein and the rotor outer cylinder that is equipped with a room temperature damper that is concentrically provided with a predetermined gap on the outside of the rotor inner cylinder. A radiation shield for a rotor of a superconducting rotating electric machine, which is provided in a gap and has a cylindrical inner and outer two-layer structure for preventing heat infiltration from the rotor outer cylinder to the rotor inner cylinder. In the manufacturing method, a radiation shielding body serving as an outer layer and a radiation shielding body serving as an inner layer are arranged concentrically and inserted into an explosion core metal having a hollow portion, and a cooling guide groove is provided in a gap between them. A plurality of filamentous low melting point metals are arranged to form a radiation shield, and the inner periphery of the radiation shield body serving as the inner layer is covered with gunpowder, and the pressure at the time of explosion is utilized by exploding this gunpowder. Then, the radiation shield body serving as the outer cylinder and the radiation shield body serving as the inner layer are explosively bonded, and then heated to melt and flow out the low melting point metal of the filaments to form a cooling duct groove in this portion. A method for manufacturing a radiation shield in a rotor of a superconducting rotating electrical machine, characterized by: