JPH0524746B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to the structure of a rotor of a superconducting rotating electric machine.

[Conventional technology]

Conventionally, this kind of rotor is known as, for example, Japanese Patent Application Laid-open No. 57-
There is one disclosed in Japanese Patent No. 22372, and its configuration is shown in FIG. In FIG. 3, 1 is a torque tube, 2 is a coil mounting shaft forming the center of the torque tube 1, 3 is a superconducting field coil fixed to the coil mounting shaft 2, and 4 is a torque tube 1.
and a room-temperature damper surrounding the coil mounting shaft 2; 5 is a low-temperature damper disposed between the room-temperature damper 4 and the coil mounting shaft 2; 6 and 7 are mounted on the outer periphery and side surface of the coil mounting shaft 2, respectively; 8 and 9 are drive side and non-drive side end shafts, 10 is a bearing that pivotally supports these end shafts 8 and 9, and 11 is a slip for supplying field current. ring, 17 is a heat exchanger formed or placed in the torque tube 1, 13 is a side radiation shield,
14 is a vacuum section.

In the rotor of the superconducting rotating machine having the above configuration, the superconducting field coil 3 disposed on the coil mounting shaft 2 is cooled to an extremely low temperature to bring the electrical resistance to zero and eliminate excitation loss. As a result, a strong magnetic field is generated in the superconducting field coil 3, and AC power is generated in the stator (not shown). In order to cool and maintain this superconducting field coil 3 at an extremely low temperature, liquid helium is introduced from the center of the non-drive side end shaft 9 through a pipe (not shown) formed by a helium outer cylinder 6 and a helium end plate 7. The torque tube 1 is made of a thin-walled cylinder and supplies the liquid helium to the liquid helium container section in which the helium is stored, while maintaining the inside of the rotor at a high vacuum in the vacuum section 14, and transmitting rotational torque to the ultra-low temperature superconducting field coil 3 and the coil mounting shaft 2. The most common structure is to provide a heat exchanger 12 and to reduce as much as possible the heat that enters the cryogenic part through the torque tube 1. Furthermore, in order to reduce the heat that enters due to radiation from the sides, the side radiation shield 13
is provided.

On the other hand, the normal temperature damper 4 and the low temperature damper 5 have the function of shielding harmonic magnetic fields from the stator, protecting the superconducting field coil 3, and attenuating rotor vibrations caused by disturbances in the power system.
Generally, the normal temperature damper 4 functions as a vacuum outer cylinder, and the low temperature damper functions as a radiation shield for the helium container. In FIG. 3, piping constituting a helium introduction and discharge system inside the rotor and a helium introduction and discharge device connected to the rotor are omitted.

FIG. 4 is a sectional view taken along the line shown in FIG.
6 is a helium outer cylinder, 15 is a liquid helium reservoir, 16 is a helium vapor space, 17 is a slot for housing the superconducting field coil 3 formed on the coil mounting shaft 2, and 18 is a slot on both sides of the slot 17. The disposed side claws include a wedge 19 for fixing the superconducting field coil 3, and 20 and 21 an upper claw and a lower claw that are in contact with the outer circumferential surface and inner circumferential surface of the superconducting field coil 3, respectively. For example, it has circular through holes 20a and 21a.
22 is a helium flow path provided between the coil mounting shaft 2 and the helium outer cylinder 6, and 23 is a coil mounting shaft helium flow hole provided in communication with the liquid reservoir 15 and the bottom of the slot 17.

Generally speaking, in superconducting rotating electric machines, there is an important technical problem in how to cool the superconducting field coil to a cryogenic temperature. 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 1K to 20K. On the other hand, in such extremely low temperature conditions, the specific heat of the superconducting field coil is extremely small, so the superconducting field coil is heated by a small amount of heat generated within the superconducting field coil or by a small amount of heat entering the superconducting field coil. There is always a risk that the temperature of the coil will rise and exceed the superconducting transition temperature. Therefore, in the design of superconducting rotating electric machines, it is important to suppress the temperature rise of the superconducting field coil by quickly removing the minute amount of heat generated within the superconducting field coil or the slight amount of heat entering the superconducting field coil. This is a great point.

Next, the cooling operation will be explained based on FIG. 5. The heat generated by slight heat generation within the superconducting field coil 3 or by slight heat intrusion into the superconducting field coil 3 is absorbed by the helium that exists in a small space around the superconducting field coil 3. be done. The helium, which expands due to heat absorption and becomes less dense, flows through the through hole 21 of the lower cuff 21 due to the natural convection of the centrifugal force field.
a, and exits to the liquid reservoir 15 through the helium flow hole 23 of the coil mounting shaft 2. On the other hand, the helium shortage that occurs around the superconducting field coil 3 is compensated for by helium flowing from the helium channel 22 into the area around the superconducting field coil 3 through the gap between the wedges 19 and the through hole 20a of the upper pawl 20. be exposed.
The endothermically expanded helium is cooled in the liquid reservoir 15 by partially evaporating it. The cooled helium enters around the superconducting field coil 3 through the helium flow hole 23 of another coil mounting shaft, through the through hole 21a of the lower pawl 21, and further into the through hole 20a of the upper pawl 20 and the bottom of the wedge 19. It exits to the helium flow path 22 through the gap.

By performing the smooth self-circulation as described above, the superconducting field coil 3 is cooled, and the superconducting field coil 3 is kept below the superconducting transition temperature.

[Problem that the invention seeks to solve]

In the rotor of a conventional superconducting rotating electric machine, the through holes 20a, 2 of the upper pawl 20 and the lower pawl 21 are
0a is only in the radial direction and the distance between them in the axial direction is wide.
As shown in FIG. 5, there is a large difference in the length of the helium flow path at a location far away from 0a. Therefore, if slight heat generation or slight heat intrusion occurs in a place far away from the through holes 20a, 20a, the helium that has absorbed the heat will be difficult to escape to the coil mounting shaft helium flow hole 23, and the helium at this location will be There was a problem in that the temperature of the superconducting field coil 3 rose and easily exceeded the superconducting critical temperature, leading to quenching.

This invention was made to solve the above-mentioned problems, and aims to provide a rotor for a superconducting rotating electrical machine that can smoothly remove heat from a superconducting field coil and improve the performance of the superconducting field coil. purpose.

[Means for solving problems]

The rotor of a superconducting rotating electric machine according to the present invention has a first channel groove having a channel extending in the axial direction and a channel extending in the width direction, which is formed on a surface of the upper part of the nail not in contact with the superconducting field coil. , a plurality of first small holes formed in a channel extending in the axial direction and a channel extending in the width direction of the first channel groove, and an axis formed in a surface of the lower parting that is in contact with the superconducting field coil. a second channel having a channel extending in the direction and a channel extending in the width direction;
, and a plurality of second small holes formed in a channel extending in the axial direction and a channel extending in the width direction of the second channel groove.

[Effect]

The rotor of the superconducting rotating electrical machine in this invention is
The first flow groove and first small hole formed in the upper pawl and the second flow groove and second small hole formed in the lower pawl allow helium to flow well in the axial and width directions. Therefore, heat can be smoothly removed from the superconducting field coil, and the performance of the superconducting field coil is improved.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. In Figures 1 and 2, 2, 3, 6, 1
5, 16, 19, 22, and 23 have the same structure as the conventional rotor described above. 24 is an upper pawl in contact with the outer peripheral surface of the superconducting field coil 3; 25 is a channel extending in the axial direction formed on the surface of the upper pawl 24 in contact with the superconducting field coil 3, and in the width direction of the superconducting field coil 3; The first flow groove 26 is a plurality of first small holes formed in the first flow groove 25, and the first flow groove 26 is a plurality of first small holes formed in the first flow groove 25. It is formed. 27 is a lower pawl that is in contact with the inner peripheral surface of the superconducting field coil 3. Reference numeral 28 denotes a second channel groove 29 formed of a channel extending in the axial direction and a channel extending in the width direction of the superconducting field coil 3 formed on the surface of the lower pawl 27 in contact with the superconducting field coil 3; A plurality of second small holes are formed in the second flow path groove 28, and are also formed in a portion facing the coil mounting shaft helium flow hole 23.

Next, the operation will be explained. The heat generated by the slight heat generated by the superconducting field coil 3 or by a slight amount of heat entering the superconducting field coil 3 is absorbed by the helium that exists in a small space around the superconducting field coil 3. Ru. The helium, which expands due to heat absorption and has a lower density, enters the second small hole 29 of the lower cuff 27 by natural convection of the centrifugal force field, and passes through the second flow channel groove 28 of the lower cuff 27. The coil mounting shaft exits to the liquid reservoir 15 through the helium flow hole 23. On the other hand, the helium shortage occurring around the superconducting field coil 3 causes the helium flow path 22 to
9 and the first channel groove 2 of the upper pawl 24
5 and flowing around the superconducting field coil 3 through the first small hole 26 of the upper pawl 24. The endothermically expanded helium is cooled in the liquid reservoir 15 by partially evaporating it. The cooled helium passes from the helium flow hole 23 on another coil mounting shaft through the second flow groove 28 of the lower pawl 27, passes through the second small hole 29 of the lower pawl 27, and enters the superconducting field coil 3.
The first small hole 26 of the upper pawl 24, the first channel groove 25 and the wedge 1
9 and exits to the helium flow path 22. By performing smooth natural circulation in this manner, the superconducting field coil 3 is cooled, and the superconducting field coil 3 is kept below the superconducting transition temperature.

〔Effect of the invention〕

As explained above, the present invention includes a first channel groove having a channel extending in the axial direction and a channel extending in the width direction, which is formed on the surface of the upper nail that is in contact with the superconducting field coil; A plurality of first small holes are formed in the axially extending channel and the widthwise channel of the channel groove, and the axially extending channel is formed in the surface of the lower parting that is in contact with the superconducting field coil. a second channel groove having a channel extending in the width direction; and a plurality of second small holes formed in the channel extending in the axial direction and the channel extending in the width direction of the second channel groove. Therefore, it is possible to obtain a rotor for a superconducting rotating electrical machine that improves helium flow in the axial and width directions, allows smooth heat removal from the superconducting field coil, and improves the performance of the superconducting field coil. can.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the flow of helium in the rotor of a superconducting rotating electrical machine according to an embodiment of the present invention, FIG. 2 is a plan view showing the upper and lower parts of the invention, and FIG. A cross-sectional view showing the overall concept of the rotor of a general superconducting rotating electric machine, Fig. 4 is a cross-sectional view along the line shown in Fig. 3, and Fig. 5 is a cross-sectional view showing the flow of helium in the rotor of a conventional superconducting rotating electric machine. It is. In the figure, 2 is a coil mounting shaft, 3 is a superconducting field coil, 17 is a slot, 24 is an upper pawl, 25 is a first channel groove, 26 is a first small hole, 2
7 is a lower pawl, 28 is a second channel groove, and 29 is a second small hole. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. In a superconducting field coil housed in a slot provided in a coil mounting shaft, and an upper claw and a lower claw that are in contact with the outer circumferential surface and inner circumferential surface of the superconducting field coil, respectively, the above-mentioned upper claw a first channel groove having an axially extending channel and a widthwise channel formed on a surface in contact with the superconducting field coil; a channel extending in the axial direction of the first channel groove; and a plurality of first small holes formed in a channel extending in the width direction, a channel extending in the axial direction formed in a surface of the lower pawl that is in contact with the superconducting field coil, and a channel extending in the width direction. A superconducting rotation characterized by comprising: a second passage groove having a second passage groove, and a plurality of second small holes formed in a passage extending in the axial direction and a passage extending in the width direction of the second passage groove. Electric machine rotor.