JPH0851766A - Superconducting rotor - Google Patents

Abstract

PURPOSE:To prevent leakage of a gaseous refrigerant from the inside of a winding fixing shaft into a collector ring coupling shaft fixed to the end part shaft thereof. CONSTITUTION:A winding fixing shaft 1 applied with a superconducting field winding 2 is arranged coaxially, on the outside diameter side thereof, with an outer tube 4 through a vacuum heat insulation layer 3. The winding fixing shaft and the outer tube are supported, at the opposite end parts thereof, by end part shafts 5a, 5b. A current lead 8 penetrates one end part shaft 5b coupled with a collector coupling shaft 6 having outer circumferential face fixed with a collector ring 11 which is connected through a stud with the outside end of the current lead 8. Furthermore, a hermetic seal 13 is provided between the current lead and one end part shaft. In such superconducting rotor, a gas chamber 16 isolated from the outside of the machine is formed in the collector coupling shaft 6 by hermetically sealing 14 the gap between the stud 10 and the through hole of the collector coupling shaft 6 and a gas excellent in breakdown strength is encapsulated in the gas chamber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superconducting rotor using a superconducting winding as a rotor winding.

[0002]

2. Description of the Related Art A conventional superconducting rotor has a structure as shown in FIG. In FIG. 2, 1 is a winding mounting shaft having a hollow portion 1a in which liquid helium is stored,
A superconducting field winding 2 cooled by liquid helium is wound around the winding mounting shaft 1. An outer cylinder 4 is coaxially arranged on the outer diameter side of the winding mounting shaft 1 with a vacuum heat insulating layer 3 interposed therebetween. Both ends of the winding mounting shaft 1 and the outer cylinder 4 are turbine side end shafts 5a. It is also supported by an end shaft 5b on the helium transfer coupling (HTC) side.

A collector ring joint shaft 6 is connected to the HTC side end shaft 5b, and axially penetrates through the rotation center axes of the HTC side end shaft 5b and the collector ring joint shaft 6 to form a winding mounting shaft. A helium supply / exhaust pipe 7 for supplying liquid helium into the inside of the chamber 1 and collecting evaporative gas helium is installed. Further, a current lead guide 9 in which a tubular current lead 8 for supplying a current to the superconducting field winding 2 is inserted into the outer diameter side HTC side end shaft 5b of the helium supply / discharge pipe 7 is axially penetrated. Have been installed.

In this case, the current lead guide 9 is welded to the winding mounting shaft 1 and the HTC side end shaft 5b to keep the vacuum heat insulating layer 3 airtight. The current lead 8 is connected to the superconducting field winding 2 inside the machine.

On the other hand, the axial end side of the current lead 8 is inserted into the collector ring joint shaft 6, and its end is connected to the collector ring 11 mounted on the outer peripheral surface of the collector ring joint shaft 6 via the rising stud 10. To be done. In this case, the rising stud 10 is the rising stud insulator 12
It is insulated from the ground. Further, in order to prevent the gas helium leaking through the gap between the current lead 8 and the current lead guide 9 between the current lead 8 and the end side shaft 5b on the HTC side from filling up near the rising stud insulator 12. , A first airtight seal portion 13 using rubber or the like is provided,
The seal is done.

[0006]

In the superconducting rotor having such a structure, the current lead 8 and the HTC side end shaft 5 are provided.
The vicinity of the first airtight seal portion 13 provided between b is likely to be low in temperature due to the low temperature gas helium discharged through the current lead 8 even during steady operation, and is particularly low during cool down operation. .

Normally, packing is used as the material of the hermetically sealed portion 13, but the sealing ability of this packing decreases as the temperature decreases, so that gas helium may leak. When the gas helium leaks, the gas helium rises and fills the vicinity of the stud insulator 13.

On the other hand, the rising stud insulator 12 has a creeping insulation portion, but the insulation strength decreases as the gas helium concentration increases, and in particular, in the field current control type superconducting generator, very high forcing occurs. When a voltage is applied, the rising stud insulator 12 may cause a ground fault.

As described above, even if the airtight seal portion 13 is provided in the gap between the current lead 8 and the current lead guide 9, a highly reliable sealing structure such as welding cannot be obtained. If leaked, the reliability of the rising stud insulator 12 with respect to the dielectric strength is deteriorated. In particular, since the airtight seal portion 13 is not monitored, if the leaked helium gas concentration becomes high, a ground fault may occur in the rising stud insulator 12, which may lead to a serious accident.

The present invention has been made in view of the above circumstances, and prevents leakage of the gas refrigerant from the inside of the winding mounting shaft to the collector ring splice shaft mounted on the end shaft of the winding mounting shaft. An object of the present invention is to provide a superconducting rotor capable of improving the reliability with respect to the dielectric strength.

[0011]

In order to achieve the above object, the present invention constitutes a superconducting rotor by the following means. The invention corresponding to claim 1 has a hollow mounting portion in which a liquid refrigerant is stored, and a winding mounting shaft around which a superconducting winding cooled by the liquid refrigerant is wound, and an outer diameter of the winding mounting shaft. The outer cylinder coaxially disposed on the side with a vacuum heat insulating layer, an end shaft supporting both ends of the winding mounting shaft and the outer cylinder, and one of the end shafts is wound in the axial direction. A current lead, which is provided so as to penetrate through the hollow portion of the wire mounting shaft and is connected to the superconducting winding, a collector joint shaft connected to the one end shaft, and a collector lead shaft mounted on the outer peripheral surface of the collector joint shaft. A superconducting rotor comprising: a collector ring to which an outboard end of a current lead is connected via a rising stud; and a hermetic seal for sealing a gap between the current lead and one end shaft, wherein Rising stud connected to the ring An airtight seal is provided to seal the gap between the rising hole and the through hole of the collector joint shaft, and a gas chamber isolated from the outside of the machine is formed inside the collector joint shaft. This gas chamber has excellent withstand voltage. Fill with gas.

The invention corresponding to claim 2 is the above claim 1.
In addition to the configuration of the invention corresponding to the above, a pressure monitoring sensor for monitoring the pressure of the gas with excellent withstand voltage sealed in the gas chamber is provided.

The invention according to claim 3 has a winding mounting shaft having a hollow portion in which a liquid refrigerant is stored, and around which a superconducting winding cooled by the liquid refrigerant is wound, and this winding mounting shaft. An outer cylinder coaxially arranged on the outer diameter side of the coil through a vacuum heat insulating layer, end shafts that support both ends of the winding mounting shaft and the outer cylinder, and one of the end shafts A current lead connected to the superconducting winding and penetrating into the hollow part of the winding mounting shaft, a collector joint shaft connected to the one end shaft, and an outer peripheral surface of the collector joint shaft. In a superconducting rotor having a collector ring attached to which an outboard end of the current lead is connected via a rising stud, and a hermetic seal for sealing a gap between the current lead and one end shaft. , The collector joint near the airtight seal Is provided with a superconducting monitoring sensor, characterized in that a gas helium concentration monitoring sensor for monitoring the gas helium concentration in the shift.

[0014]

In the superconducting rotor of the invention according to claim 1, the gas chamber formed in the collector ring joint shaft outside the machine by the airtight seal has a dry withstand voltage higher than the gas helium pressure inside the machine. Since excellent gas is enclosed, the gas helium does not flow into the gas chamber, and it is possible to prevent the gas helium from being filled in the vicinity of the rising stud insulator.

In the superconducting rotor according to the second aspect of the invention, the change in the pressure value of the gas sealed in the gas chamber and having an excellent withstand voltage is monitored by the pressure monitoring sensor, so that the sealing performance of each hermetic seal is improved. Can be detected in advance, and when the pressure drops to a certain value, it is possible to take appropriate measures such as stopping the excitation of the superconducting field winding, and by applying a very high forcing voltage. It is possible to prevent the occurrence of a ground fault accident in the rising stud insulator, which is a concern.

In the superconducting rotor of the invention corresponding to claim 3, gas helium provided in the collector joint shaft near the airtight seal for sealing the gap between the current lead and the one end shaft. Since the gas helium concentration is monitored by the concentration monitoring sensor, it is possible to detect the deterioration of the sealing performance of the airtight seal in advance, and stop the excitation of the superconducting field winding when the concentration rises to a certain value. It is possible to prevent the occurrence of the ground fault accident in the rising stud insulator which may be caused by the application of a very high forcing voltage.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of the configuration of the main part of a superconducting rotor according to the present invention. Note that other configurations are the same as those in FIG. 2, and therefore illustration and description thereof are omitted.

As shown in FIG. 1, a tubular current lead 8 whose surface is insulated by a current lead insulator 8b has one H
It is inserted into a current lead guide 9 which is provided by penetrating the TC side end shaft 5b in the axial direction. The current lead guide 9 is welded to the winding mounting shaft 1 and the HTC-side end shaft 5b to keep the vacuum heat insulating layer 3 airtight.

The current lead guide 9 is connected to the superconducting field winding 2 from the hollow portion 1a of the winding mounting shaft 1 inside the machine, that is, at the end located inside the collector joint shaft 6 outside the machine, with the rising stud. Collector joint shaft 6 through 10
Is connected to a collector ring 11 attached to the outer peripheral surface of the. In this case, the rising stud 10 is ground-insulated by the rising stud insulator 12 inserted into the through hole of the collector joint shaft 6 that is pulled out to the collector ring 11 side.

On the other hand, the current lead 8 and the HTC side end shaft 5b
The first airtight seal 13 made of rubber or the like is provided between
Is provided to prevent the gas helium that leaks through the gap between the current lead 8 and the current lead guide 9 from filling the vicinity of the rising stud 10.

A second hermetic seal 14 is provided on the coupling surface between the end shaft 5b on the HTC side and the collector joint shaft 6, and a third hermetic seal 15 is provided in a through hole provided in the collector joint shaft 6. It is provided.

Therefore, the first hermetic seal 13 for sealing between the HTC side end shaft 5b and the current lead 8 and the third hermetic seal for sealing between the rising stud 10 and the through hole of the collector joint shaft 6. Due to 15, a closed gas chamber 16 is formed in the collector joint shaft 6.

The gas chamber 16 is filled with a dry gas having a high withstand voltage higher than the gas helium pressure inside the machine, and a pressure monitoring sensor 17 for monitoring the pressure of the filled gas is provided.

Similarly, a gas helium concentration monitoring sensor 18 for detecting gas helium leaking from the first hermetic seal 13 is provided in the gas chamber 16 near the first hermetic seal 13. With the superconducting rotor having such a configuration, the gas helium leaking through between the current lead 8 and the current lead guide 9 is sealed by the first hermetic seal 13.

However, the vicinity of the first hermetic seal 13 is exposed to a low temperature by the gas helium discharged through the current lead 8 during operation, and the first hermetic seal 13 should be exposed.
Even if gas helium may leak from the first hermetic seal 13 due to the deterioration of the sealing function of the first hermetic seal 13, the first hermetic seal 13 and the third hermetic seal 15 are formed in the collector ring joint shaft 6 on the outer side of the machine. The gas chamber 16 is filled with a dry gas having a withstand voltage higher than the gas helium pressure inside the machine, so that the gas helium does not flow out into the gas chamber 16 and the gas near the rising stud insulator 12 is prevented. It is possible to prevent the helium from being filled.

The pressure monitoring sensor 17 monitors changes in the pressure value of the gas sealed in the gas chamber 16 and having an excellent withstand voltage, so that the first to third hermetic seals 13, 14,
It is possible to detect in advance the deterioration of the sealing performance of No. 15,
When the pressure drops to a certain value, it is possible to take appropriate measures such as stopping the excitation of the superconducting field winding. It is possible to prevent the occurrence of an accident.

Similarly, since the gas helium concentration monitoring sensor 18 provided in the gas chamber 16 near the first hermetic seal 13 is used to monitor the gas helium concentration, the sealing performance of the first hermetic seal 13 is reduced. It can be detected in advance, and when the concentration rises to a certain value, it is possible to take appropriate measures such as stopping the excitation of the superconducting field winding, which is a concern due to the application of a very high forcing voltage. It is possible to prevent occurrence of a ground fault accident in the rising stud insulator 12.

When the gas helium concentration monitoring sensor 18 provided in the gas chamber 16 near the first hermetic seal 13 is used to monitor the gas helium concentration, the second gas chamber 16 for forming the gas chamber 16 is not always required. It is not necessary to use it together with the third hermetic seals 14 and 15.

[0029]

As described above, according to the present invention, the sealing function of the hermetic seal for sealing the gap between the current lead and the end shaft supporting the end of the winding mounting shaft is deteriorated. Also, the insulation strength of the current lead can be prevented, which can prevent the ground fault accident that occurs when gas helium is filled near the insulator that has the creepage insulation part of the rising stud that connects to the collector ring through the collector ring joint shaft outside the machine. On the other hand, it is possible to provide a highly reliable superconducting rotor.

[Brief description of drawings]

FIG. 1 is a sectional view showing a main part of an embodiment of a superconducting rotor according to the present invention.

FIG. 2 is a cross-sectional view showing a configuration example of the entire conventional superconducting rotor.

[Explanation of symbols]

1 ... Winding attachment shaft, 2 ... Superconducting field winding, 3 ... Vacuum heat insulating layer, 4 ... Outer cylinder, 5a, 5b ... End shaft, 6 ...
Collector ring joint shaft, 7 ... Helium supply and exhaust pipe, 8
... current lead, 9 ... current lead guide, 10 ... rise stud, 11 ... collector ring, 12 ... rise stud insulator, 13 ... first hermetic seal, 14 ...
… Second airtight seal, 15 …… Third airtight seal, 16
...... Gas chamber, 17 ...... Pressure monitoring sensor, 18 ...... Gas helium concentration monitoring sensor.

Claims (3)

[Claims] 1. A winding mounting shaft having a hollow portion in which a liquid refrigerant is stored, around which a superconducting winding cooled by the liquid refrigerant is wound, and vacuum insulation on the outer diameter side of the winding mounting shaft. An outer cylinder coaxially arranged via layers, an end shaft supporting both ends of the winding mounting shaft and the outer cylinder, and one of the end shafts of the end shaft of the winding mounting shaft in the axial direction. A current lead provided through the hollow portion and connected to the superconducting winding, a collector joint shaft connected to the one end shaft, and a current lead machine mounted on the outer peripheral surface of the collector joint shaft. In a superconducting rotor having a collector ring whose outer end is connected through a rising stud and an airtight seal that seals the gap between the current lead and one end shaft, the superconducting rotor is connected to the collector ring. Rising stud and this rising stud An airtight seal that seals the gap between the through hole of the collector joint shaft from which the tod comes out is formed to form a gas chamber isolated from the outside of the machine inside the collector joint shaft.
A superconducting rotor characterized in that a gas having a high withstand voltage is filled in this gas chamber. 2. The superconducting rotor according to claim 1, further comprising a pressure monitoring sensor for monitoring the pressure of the gas having a high withstand voltage enclosed in the gas chamber. 3. A winding mounting shaft having a hollow portion in which a liquid refrigerant is stored, and around which a superconducting winding cooled by the liquid refrigerant is wound, and vacuum insulation on the outer diameter side of the winding mounting shaft. An outer cylinder coaxially arranged via layers, an end shaft supporting both ends of the winding mounting shaft and the outer cylinder, and one of the end shafts of the end shaft of the winding mounting shaft in the axial direction. A current lead provided through the hollow portion and connected to the superconducting winding, a collector joint shaft connected to the one end shaft, and a current lead machine mounted on the outer peripheral surface of the collector joint shaft. In a superconducting rotor having a collector ring whose outer end is connected via a rising stud and an airtight seal that seals the gap between the current lead and one end shaft, a collector in the vicinity of the airtight seal Gas helium concentration in the joint shaft A superconducting rotor characterized by being provided with a gas helium concentration monitoring sensor for monitoring the superconducting rotor.