JPS63228957A - Rotor for superconducting rotary electric machine - Google Patents

Abstract

PURPOSE:To permit the prevention of the damage of welded parts on a helium outer tube without spoiling the flow of liquid helium, necessary for the cooling of a superconducting field coil, by a method wherein both ends of the helium outer tube are engaged with a coil mounting shaft while the engaging parts are welded. CONSTITUTION:A rotor is constituted by a method wherein both ends of a helium outer tube 6 are engaged with a coil mounting shaft 2 and the engaging parts are welded while a helium flow passage 22 is formed between the outer surface of a wedge 17 and the helium outer tube 6 and axial grooves 24 as well as circumferential grooves 25, which intersect with slots 16, are formed. According to this constitution, liquid helium, from helium distributing groove 3, flows to outer helium passages 22 through the axial grooves 24 and the circumferential grooves 25. The liquid helium in the outer helium passage 22 flows from the gaps between mutual wedges 17 through the upper radial hole 21b of an insulating spacer 21 and cools a superconducting field coil 3. The liquid helium, whose temperature has risen by cooling the superconducting field coil 3, passes through a lower radial hole 21a and the helium flow passage hole 20 of the slots, then, flows out to a liquid helium reservoir 15.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a rotor for a superconducting rotating electric machine, and more specifically, a superconducting field coil housed in a slot formed on the surface of a coil mounting shaft. It is held with a wedge and has a helium outer cylinder on the outer periphery of the coil installation @1 (super-possible).
It concerns the rotor of a rotary military aircraft.

[Conventional technology]

Conventionally, this type of rotor is described in Japanese Patent Application Laid-Open No. 57-202852 as shown in FIGS. 7-1 to 11. In FIG. 7, a superconducting field coil (3) is fixed to a coil mounting shaft (2) forming the center portion of a torque tube (1). The torque tube (1) and the coil mounting shaft (2) are surrounded by a normal temperature damper (4). A low temperature damper (5) is installed between the room temperature damper (4) and the coil mounting shaft (2).
) are provided. (6) and (7) are the helium outer cylinder and helium end plate attached to the outer periphery and side surface of the coil mounting shaft (2), respectively, and (6a) is the helium outer cylinder attached to the coil mounting shaft (2). This is the welding part. It is supported by bearings (1o) of the drive side and non-drive side end shafts (8) and (9). (11) is a slip ring for supplying field current. The torque tube (1) is equipped with a heat exchanger (1
2) is formed or arranged. (13) is a side radiation shield, and (14) is a vacuum part.

In the rotor of the superconducting rotating electric machine having the above configuration,
By cooling the superconducting field coil (3) disposed on the coil mounting shaft (2) into a low-temperature fan, the electric resistance is reduced to a constant state and excitation loss is eliminated. (3) A strong magnetic field is generated in the stator (not shown) to generate alternating current power.

In order to cool and maintain this superconducting field coil (3) at an extremely low temperature, liquid helium is introduced into the helium outer cylinder (6) from the center of the non-drive side end I41 (9) through an introduction pipe (not shown).
, the liquid helium is supplied to the ram reservoir (15) formed by the helium end plate (7), while the inside of the rotor is supplied to the vacuum section (14).
) to maintain a high vacuum, the ultra-low temperature superconducting field coil (3) and the coil mounting shaft (2). This is to reduce as much as possible the heat that enters the cryogenic part through the torque tube (1). Further, a side radiation shield (13) is provided to reduce heat entering due to radiation from the sides.

On the other hand, the room temperature damper (4) and the low temperature damper (5) are
In addition to shielding harmonic magnetic fields from the stator and protecting the superconducting field coil (3), it also has the function of damping rotor vibrations caused by disturbances in the power system.The normal temperature damper (4) also functions as a vacuum outer cylinder. The low-temperature damper (5) also serves as a radiation shield for the helium container. In addition, in FIG. 7, piping constituting a helium introduction and discharge system inside the rotor and a helium introduction and discharge device connected to the rotor are omitted.

As shown in FIG. 8, the superconducting field coil (3) consists of a straight portion (3a) and an end portion (3b).

As shown in Figure 9, the superconducting field coil (3) has a slot (16) formed on the surface of the coil mounting H (2).
and is secured within the slot (16) with a wedge (17). There are teeth (
18) is formed. (19) is a shaft end helium channel hole.

As shown in Fig. 10, the cooling channel of the superconducting field coil (3) consists of a liquid helium reservoir (15), a coil mounting shaft (2
) Helium flow path hole (20) formed in the slot part, lower part for liquid helium flow path formed in the insulating spacer (21) that fills the gap between the superconducting and conducting field coil (3) and the slot (16) Radial hole (21a), upper radial hole (2
1b). The upper radial hole (21b) is
It is adjusted to match the gap between two adjacent wedges (17), and the helium channel (22) on the outer diameter side is surrounded by the coil installation [+411 (2) and the helium outer cylinder (6)].
is connected to.

The shaft end helium channel hole (
19) is the coil mounting shaft (2) as shown in Fig. 11.
Liquid helium reservoir (15) on the inner diameter side and coil mounting shaft (2)
) is in communication with the helium flow path (22) on the outer diameter side.

Here, in superconducting rotating electric machines, there is an important technical problem in how to perform cryogenic cooling of superconductor and conductor coils. In order to bring a superconducting field coil into a superconducting state, it is necessary to cool it below the superconducting transition temperature, and currently, helium is used as a cooling medium to maintain the absolute temperature at an absolute temperature of 1 to 20 K. On the other hand, in such extremely low-temperature conditions, the specific heat of the superconducting field coil is extremely small, so the superconducting There is always a risk that the temperature of the field coil will rise and exceed the superconducting transition temperature. Therefore, in the design of superconducting rotating electric machines, it is important to quickly remove the minute amount of heat generated within the superconducting field coil or the slight amount of heat entering the superconducting field coil, thereby suppressing the temperature rise of the superconducting field coil. This is a great point.

Next, the operation of the above conventional device will be explained.

When a small amount of heat is generated within the superconducting field coil (3) or a slight amount of heat intrudes into the superconducting field coil (3), this heat is absorbed by the helium existing around the conductor. Helium that absorbs heat expands and becomes less dense, so the natural convection of the centrifugal force field causes the insulating spacer (21) to
through the lower radial hole (21a) and through the helium channel hole (20) machined in the coil mounting shaft (2).
Exit to the liquid helium pool (15). The helium that has absorbed this heat dissipates heat by partially evaporating in the liquid helium reservoir (15). On the other hand, the shortage of liquid helium that occurs around the superconducting field coil (3) is caused by the liquid helium reservoir (15) flowing through the shaft end helium channel hole (19).
and an insulating spacer (21) through the gap between the wedges (17) through the helium flow path (22) on the outer diameter side.
is supplemented by liquid helium flowing from the upper radial hole (21b) of the radial hole (21b). By performing such natural circulation, the superconducting field coil (3) is cooled.

[Problem to be solved by the invention 1 In the rotor of the conventional superconducting rotary mtb as described above, in order to form the helium channel (22) on the outer diameter side, the helium outer cylinder (6) has coils attached at both ends. It is fixed to the shaft (2) by welding, but there is a gap between the other parts and the coil mounting shaft. Therefore, when a huge transient torque is applied to the rotor due to a system short circuit accident caused by lightning, etc., different torsional vibrations are generated between the helium outer cylinder (6) and the coil mounting shaft (2).
Welded parts (
6a) and the liquid helium inside the helium container leaks into the vacuum section (14), resulting in a decrease in the degree of vacuum. As a result, the heat entering the cryogenic part increases, the temperature of the super-heavy conductive field coil (3) rises, exceeding the superconducting transition temperature, and the super-heavy four-field coil (3) quenches. There is a problem in that there is a possibility that the operation of the electrically conductive rotating electric machine may become impossible.

This invention was made in order to solve these problems, and it is possible to prevent damage to the welded part of the helium outer cylinder due to system accidents without impairing the flow of liquid helium necessary for cooling the superconducting field coil. The purpose is to obtain a rotor for a superconducting rotating electrical machine that can prevent the above problems.

[Means for solving problems]

In the rotor of a superconducting rotating electric machine according to the present invention, both ends of a helium outer cylinder are fitted to a coil mounting shaft, the fitting parts are welded, and a helium flow path is formed between the outer surface of the wedge and the helium outer cylinder. Formed, and furthermore, on the surface of the coil mounting shaft,
A groove is provided that intersects the slot and forms a helium flow path.

[For production]

In this invention, the connection between the helium outer cylinder and the coil mounting shaft is strengthened, and the two exhibit torsional motion as a unit in the event of a system accident. Furthermore, the flow of liquid helium necessary for cooling the superconducting field coil is ensured by the helium flow path between the outer surface of the wedge and the helium outer cylinder and the helium flow path formed by the groove on the surface of the coil mounting shaft.

〔Example〕

FIGS. 1 to 4 show an embodiment of the present invention. In FIG. 1, a helium outer cylinder (6) is shrink-fitted to a coil mounting shaft (2), and liquid helium is injected into a vacuum section at both ends of the helium outer cylinder (6). (1
4) has a welded part (6b) to prevent leakage.

In Fig. 2, (23) is a helium distribution groove machined in the circumferential direction, and the liquid helium flowing out from the liquid helium reservoir (15) passes through the shaft end helium channel hole (19) and passes through the helium distribution groove. (23).

In Figure 3, the top of the wedge (17) is attached to the teeth (
Wedge (17)
An outer helium flow path (22) is formed between the outer surface of the helium cylinder (6) and the helium outer cylinder (6). In addition, the coil installation shaft (2
) is provided with an axial groove (2) intersecting the slot (16).
4) and a circumferential groove (25) are formed.

In addition, the same reference numerals as in FIGS. 7 to 11 indicate the same parts, and the explanation will be omitted.

With the above configuration, liquid helium from the helium distribution groove (23) passes through the axial groove (24) and the circumferential groove (25), and flows into the external helium flow path (22). Furthermore, as shown in FIG. 4, the liquid helium in the outer helium flow path (22) passes through the gap between the wedges 07) through the upper radial hole (21b) of the insulating spacer (21), and passes through the superconducting field. It flows into the magnetic coil (3) section, and the superconducting field coil (3)
) to cool down. The liquid helium whose temperature has increased by cooling the superconducting field coil (3) flows through the lower radial hole (21a) of the insulating spacer (21) and the helium channel hole (2) in the slot portion.
0) and flows out into the liquid helium reservoir (15).

Note that the coil attachment shaft (2) and the helium outer cylinder (6) may be fitted by cold fitting, and the same effect can be obtained.

Figure 5 shows another embodiment, in which the coil is installed [! II (2)
A helium flow path consisting of an axial groove (26) intersecting with the slot (16) is provided at the top of the teeth (18) at the surface end, and the liquid helium from the helium distribution 7g (23) flows through the axial groove ( Z6), and the outer helium flow path (
22). Other operations are similar to those in the previous embodiment.

Figure 6 shows yet another embodiment, in which the coil mounting shaft (2)
On the surface of the spiral m (
27), and helium distribution g(23)
The liquid helium from the helium flow path follows the helium flow path formed by the spiral groove (27) and flows into the outer helium flow path (22). Other operations are similar to those in the previous embodiment.

〔Effect of the invention〕

As explained above, according to the present invention, the helium outer cylinder is fitted and welded to the coil mounting shaft at both ends, so that in the event of a short-circuit accident such as a lightning strike, a huge transient torque is applied to the rotor causing it to rotate. Even if torsional vibration occurs in the coil, the helium outer cylinder and the coil mounting shaft behave as one, and no shearing force is applied to the welds between the helium outer cylinder and the coil mounting shaft at both ends.

Therefore, there is no fear of damage to the welds, and a highly reliable rotor that does not leak liquid helium can be obtained.

In addition, a helium flow path on the outer diameter side is provided between the helium outer cylinder and the wedge, and a groove that intersects with the slot is provided on the surface of the coil mounting shaft. The helium that flows out to the outer diameter side of the coil mounting shaft through the hole and helium distribution passes through the groove on the surface of the coil mounting shaft and the helium flow path on the outer diameter side, and passes through the superelectric and conductive field magnet stored in the slot. It flows smoothly to the coil, effectively cooling the superconducting field coil and preventing quenching.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of one embodiment of the present invention, and FIG.
Figure 3 is a perspective view of the coil mounting shaft of Figure 1, Figure 4 is the IV of Figure 1
5 and 6 are respectively perspective views of coil mounting shafts of other embodiments, and FIG. 7 is a vertical sectional view of a rotor of a conventional superconducting rotating electrical machine. Fig. 8 is a perspective view of the superconducting field coil in Fig. 7, Fig. 9 is a perspective view of the coil mounting shaft in Fig. 7, and Fig. 10 is a perspective view of the superconducting field coil in Fig. 7.
A cross-sectional view on a plane along the X-ray, Figure 11 is of Figure 7) (-
FIG. 3 is a cross-sectional view taken on a plane along line M. (2)...Coil mounting shaft, (3)...Superconducting field coil, (6)...Helium outer cylinder, (6b)...Welded part, (1
5) @Liquid helium reservoir, (16)...slot. (17) - Wedge, (18) Fist Teeth - (19
)... Helium flow path hole at the shaft end, (20), Φ slot part (
25)...Circumferential groove, (26)...Axial inner thinness, (27
)@・Spiral groove. In each figure, the same reference numerals indicate the same or corresponding parts. 16 slot, 17 wa,, shi, 22, 24, axial groove 25°, gate direction groove 26: Ugatacho Shin 27 spiral;

Claims (5)

[Claims] (1) A coil mounting shaft that has a slot formed on its surface that accommodates the superconducting field coil, a wedge that holds the superconducting field coil in the slot, and a wedge that fits into the coil mounting shaft at both ends. a welded helium outer cylinder, forming a helium flow path on the outer diameter side between the wedge outer surface and the helium outer cylinder, and forming a helium flow path on the surface of the coil mounting shaft intersecting with the slot. The rotor of a superconducting rotating electric machine is formed by forming grooves that form a path. (2) A rotor for a superconducting rotating electric machine according to claim 1, wherein an axial groove and a circumferential groove are formed on the surface of the coil mounting shaft. (3) A rotor for a superconducting rotating electric machine according to claim 1, wherein an axial groove is formed on the end surface of the coil mounting shaft. (4) A rotor for a superconducting rotating electric machine according to claim 1, wherein a spiral groove is formed on the surface of the coil mounting shaft. (5) A rotor for a superconducting rotating electric machine according to claim 1, wherein the coil mounting shaft and the helium outer cylinder are fitted by either shrink fitting or cold fitting.