JPS60234458A - Damper shield of superconductive rotor - Google Patents

Abstract

PURPOSE:To prevent a normal temperature damper and both inner and outer holding cylinders from displacing strongly even when a defect of generating an external variation magnetic field by forming the cross sectional shape of the both inner and outer surfaces of the damper in noncircular shape and matching the contacting surface shape of the both cylinders thereto. CONSTITUTION:A normal temperature damper 1 made of good conductive material is formed on the inner and outer peripheral surfaces in noncircular regular dodecagonal shape. Holding cylinders 2, 3 are rigidly secured to the inner and outer sides of the damper 1. Thus, the inner and outer cylinders 2, 3 are formed in noncircular regular dodecagonal shape to construct a damper shield. The shield is constructed in the outer periphery of a superconductive rotor to coat the superconductive field winding. Thus, if a defect occurs at the external variation magnetic field, a shearing force is generated at the damper 1, but since the damper is formed in a polygonal shape, it is pressed by the shearing force to the cylinder 2 to prevent the damper 1 from moving by the reaction and the frictional force.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement of a damper shield of a superconducting trochanter used in a large-capacity domestic rotating electrical machine such as a generator or a harmonic generator.

[Technical background of the invention and its problems] A large-scale rotary electric motor in which a rotor is provided with a superconducting field winding has been developed. The superconducting field winding 1 must be cooled to liquid helium temperature and isolated from the influence of external fluctuating magnetic fields in order to maintain its superconductivity.

The largest cause of the external fluctuating magnetic field is the generator load P, 1, 3411 short-circuited vehicle fault. In such cases, a cylindrical room temperature damper made of a highly conductive material such as copper is used to cover the outside of the superconducting field winding (proprietary) so that the fluctuating magnetic field does not affect the superconducting field winding. is placed on the rotor, and the repulsive magnetic field generated by the eddy current generated on the surface of the room-temperature damper due to the fluctuating magnetic field cancels out the fluctuating magnetic field, thereby almost completely eliminating the influence of the external fluctuating magnetic field on the superconducting field winding. A rotor with such a structure is called a superconducting rotor.

However, since the above-mentioned room-temperature damper is made of a material with low yield strength such as copper, its strength is insufficient to withstand the centrifugal force during rotation and the external force that acts on the room-temperature damper when an external fluctuating magnetic field is generated. . To compensate for this, in the past, normal temperature dampers were manufactured in a cylindrical shape, and a damper shield with a three-layer structure was used, which was sandwiched from the inner and outer diameter sides by a cylindrical holding tube made of stainless steel or Inconel, which had a high yield strength. It was used in superconducting rotors.

In the event of an external fluctuating magnetic field generation accident, a large shearing force is generated at 1iAj between the room temperature damper and the holding cylinder. For this reason, especially if the room temperature damper is not applied to the stroke of the inner holding cylinder,
In between, the eddy current in the power damper decreases, and the external fluctuating magnetic field reaches the field winding, causing a so-called quench, where the superconducting state is broken and the superconducting state is transferred to the normal state. Therefore, it is necessary to prevent the three members 11 from shifting.

However, as mentioned above, the conventional damper shield has a cylindrical three-layer structure, so it can be shrink-fitted and cold-fitted.
The aim was to obtain close contact between the two and prevent misalignment. That is, first, the inner holding cylinder is cooled and the normal temperature damper is heated and fitted together, and then the outer holding cylinder is fitted in the same manner, but the overall length in the axial direction is long and the adhesion between the three is It was difficult to maintain large numbers. Moreover, the eddy current generated in the room-temperature damper during the accident increases the temperature of the room-temperature damper itself, and due to thermal expansion, reduces the adhesion force with the inner holding cylinder. Therefore, there has been a need for a damper shield that can strongly prevent misalignment between the room-temperature damper and the inner and outer holding cylinders.

[Object of the Invention] An object of the present invention is to provide a damper shield for a superconducting rotor that can strongly prevent misalignment between the room temperature damper and the inner and outer holding cylinders even in the event of an accident in which an externally fluctuating magnetic field is generated.

[Summary of the Invention] The present invention provides a damper shield for a superconducting rotor in which cylindrical holding cylinders are arranged on both the inside and outside of a cylindrical room-temperature damper made of a highly conductive material that encloses superconducting field windings. By making the cross-sectional shape of both the inner and outer surfaces of the room-temperature damper non-circular and matching the shape of the contact surfaces of both holding cylinders with this, the resistance to shearing force is increased in terms of shape resistance.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

Figure 1 is a perspective view of the damper shield of this embodiment, and Figure 2 is a perspective view of the damper shield of this embodiment.
The figure shows a side view of FIG. (1) is a normal temperature damper, and the cross section of both the inner and outer peripheral surfaces is a regular dodecagon.

(2) is an inner holding cylinder, and the cross section of the inner circumferential surface is circular, and the cross section of the outer circumference of 1 m is shaped to match the inner circumferential surface of the normal temperature damper (1). (The outer holding cylinder 31 has a circular cross section on its outer circumference, and a cross section on the inner circumference that matches the outer circumference of the room-temperature damper (1). The material of the room-temperature damper (1) is copper. and hold both sides 1m +, 2) + (S
The material used is stainless steel.

In addition, in Figures 1 and 2, the room temperature damper (1)
The #'j near j/+ line is added to make the distinction between the holding cylinders (2) and (8) on both sides clear, and this is not a cross-sectional representation. This damper shield constitutes the outer circumferential portion of the superconducting rotor and encloses a superconducting field winding (not shown).

Next, the effect will be explained.

If an external fluctuating magnetic field generation accident occurs during rotation of the damper shield forming the outer periphery of the superconducting rotor, a shearing force (4) is generated in the room temperature damper (1) as shown in FIG. Since the cross-sectional shape of the joint surface between the room temperature damper (1) and the inner holding cylinder (2) is polygonal, the room temperature damper (1) is pressed against the inner holding cylinder (2) by the shear force (4). Become. Therefore, the reaction force (6) from the inner holding cylinder (phantom) and the frictional force (6) act on the room temperature damper (11), and prevent the room temperature damper (1) from moving against the shearing force (4). In this way, the shear force (4) causes the Tsunehisa damper (
1) is pressed against the inner cylinder holding cylinder (2), in this embodiment, it is possible to firmly support the normal temperature damper (1), and it is possible to avoid shrink fitting of the triple cylinder as in the conventional case. By cold fitting, there is no need to try to tightly support the room temperature damper and the holding tubes on both sides, and it is possible to do it with a simple shrink fitting or eliminate such work, and it is easy to manufacture. Become.

In addition, in the event of an external fluctuating magnetic field accident, the outer holding cylinder (81
The #1 current is generated in (1), and this force forces the room temperature damper (1) even more strongly against the inner holding cylinder (2), further increasing safety.

FIG. 4 shows the main parts of another embodiment.

This is because the normal temperature damper (1) is divided into an initial number of parts in the circumferential direction, and the circumferential end of the divided side (1a) is provided with an overlapping part (7) where adjacent dampers overlap each other in the radial direction (c). The rest is the same as the embodiment shown in FIGS. 1 and 2.

In this way, the inner holding cylinder (2) and the outer holding cylinder (3)
) can be assembled by sequentially inserting the divided pieces (la) from the axial direction, so shrink fitting and cold fitting operations can be completely eliminated. And the adjacent segment (l
a), (la) Comrades are overlapping parts (7), (7
) are firmly in contact with each other due to centrifugal force, so the electrical characteristics are similar to those of the integrated room temperature damper (1), and as shown in Figures 1 and 2.
The same effects as the embodiment shown in the drawings can be obtained.The present invention is not limited to the embodiments described above and shown in the drawings. Of course, various modifications can be made without changing the gist thereof, such as the cross-sectional shape of the joint surface with the tubes (2) and (8) need not be polygonal but may be non-circular.

[Effects of the Invention] As explained above, according to the present invention, the room temperature damper is pressed against the inner holding cylinder in the event of an external fluctuating magnetic field generation accident, so that reaction force and frictional force from the inner holding ring are not generated. This can counter the shearing force and prevent the room temperature damper from moving in the circumferential direction. Therefore, it is possible to reduce or eliminate the conventionally difficult work of shrink fitting and cold fitting of triple tubes, and to provide a damper shield for a superconducting rotor that is easy to manufacture, sufficiently strong, and highly reliable. can.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of the damper shield of a superconducting rotor of the present invention, Fig. 2 is a side view of Fig. 1, and Fig. 3 illustrates the operation of the embodiment of Fig. 1. FIG. 4 is a side view of a main part showing another embodiment. 1... Normal temperature damper 18... Divided piece 2... Inner holding cylinder 3... Outer holding cylinder 7... Overlapping section agent Patent attorney Mr. Inoue No. 1 Fig. 2 Fig. 3 Fig. 1 No. 4 Figure

Claims (1)

[Scope of Claims] (1) A damper shield for a superconducting rotor (two or more (2) The non-circular shape of the superconducting rotor is characterized by the fact that the cross-sectional shape of both the inner and outer surfaces of the room-temperature damper is non-circular, and the shape of the contact surfaces of both holding cylinders is matched to this shape. A superconducting rotor (-shield) according to claim 1, characterized in that the damper has a polygonal shape. are in contact with each other in the radial direction (
A damper shield for a Mi conductive rotor according to claim 1 or 2, characterized in that two overlapping capitals are provided.