JPH04207967A - Superconducting motor - Google Patents

Abstract

PURPOSE:To prevent intrusion of heat from the outside by winding a pipe, for discharging evaporation gas produced in a liquid medium tank, around the liquid medium tank. CONSTITUTION:A liquid nitrogen temperature section disposed around a liquid helium tank comprises a liquid nitrogen tank 2, a thin radiation shielding board, a thick radiation shielding board, a build up part, and a radiation shielding board. A nitrogen gas discharging pipe 12 discharges evaporated nitrogen gas from the liquid nitrogen tank 2. The nitrogen gas discharge pipe 12 is wound into a coil from the most remore position to the vicinity of the liquid nitrogen tank 2 while contacting with the outside of the thick radiation shielding board. The pipe 12 is wound such that the turning interval decreases gradually from the most remote position toward the liquid nitrogen tank 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a compact superconducting motor that can be mounted on an electric vehicle.

[Prior Art] In the current situation where room-temperature superconducting materials have not yet been developed, superconducting coils must be cooled to extremely low temperatures in order to maintain their superconducting state. To this end, there are various problems to be solved, such as how to prevent heat entering from the case of the superconducting motor from reaching the superconducting coil. Conventionally, as a general technique for maintaining a superconducting state, a structure is used in which liquid helium (superconducting maintenance temperature section) in which a superconducting coil is immersed is surrounded by a liquid nitrogen layer (intermediate temperature section) to insulate it. It is known as a cryostat.

[Invention or problem to be solved]

However, especially in small horizontal superconducting motors such as those used in automobiles, a liquid cooled to an intermediate temperature is used between the liquid helium temperature section, which is the superconducting maintenance temperature, and the superconducting motor case temperature, that is, room temperature. In order to provide a nitrogen temperature section, it is not possible to surround the entire liquid helium temperature section with a liquid nitrogen tank due to size constraints of the entire device of a small superconducting motor. Therefore, an object of the present invention is to provide a superconducting motor that has a compact structure that prevents heat from entering from the outside.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention provides a superconducting motor having a superconducting coil in the stator section, in which a superconducting maintenance temperature section surrounding the superconducting coil is surrounded by an intermediate temperature section including a plate having a radiation shielding function. The radiation shielding plate is thermally coupled to a tank containing a liquid medium for maintaining an intermediate temperature, and an exhaust pipe for exhausting evaporated gas generated from the tank containing the liquid medium is connected to the radiation shielding plate. The coil is wound into a coil shape, with the winding beginning at a position farthest from the tank containing the liquid medium and in contact with a plate having a shielding effect, and the winding ending near the tank containing the liquid medium.

[Effect]

An intermediate temperature section, for example, a section cooled by liquid nitrogen, is surrounded by a superconducting maintenance temperature section, for example, a liquid helium temperature section, with a plate having a radiation shielding function that is thermally coupled to a liquid nitrogen tank. However, if the plate having a radiation shielding effect is simply cooled by conduction from the liquid nitrogen tank, the temperature distribution of the plate having a radiation shielding effect will not be uniform. In order to take advantage of the cooling effect of low-temperature nitrogen gas that is still close to the liquid nitrogen temperature produced by evaporation in the liquid nitrogen tank, the gas nitrogen exhaust pipe from the liquid nitrogen tank is connected to the outside of the plate that has a radiation shielding effect. It is wound into a coil shape in contact with the In order to make the heat distribution uniform on the plate that acts as a radiation shield, we first wrap the gas nitrogen exhaust pipe from the liquid nitrogen tank over the plate that acts as a radiation shield, starting from the farthest point from the liquid nitrogen tank. The beginning and end of the winding were placed near the liquid nitrogen tank.

〔Example〕

FIG. 1 is a vertical cross-sectional view in the axial direction of a horizontal superconducting motor according to an embodiment of the present invention, FIG. 2 is a horizontal cross-sectional view in the same axial direction, and FIG. 3 is an enlarged view of the portion shown in FIG. 1. FIG. 4 is a sectional view taken along line BB in FIG. 1, and FIGS. 5 and 6 are conceptual diagrams illustrating the intermediate temperature section of the present invention.

The horizontal superconducting motor of the present invention will be explained based on FIGS. 1 to 6.

1 shows the outer case of the superconducting motor. A shaft 15 that transmits the rotation of the motor, located near the center of the internal space of the case 1 but slightly eccentrically downward, is rotatably fixed to the case 1 by a bearing, and a rotor 8 is rotated around the shaft 15. is fixed. The rotor 8 has a rotor winding portion 9 at its tip, and is rotatably fixed by a bearing.

The stator section is separated from the rotor section by a thin cylindrical partition wall 6 so as to surround the rotor section where the rotor 8 is present, and is kept in a vacuum by the partition wall 6 and the case 1. In the stator section, a liquid helium tank 3, which is a superconductivity maintaining temperature section, is provided in close proximity to the partition wall 6 and surrounding the partition wall 6.

In the liquid helium tank 3, a superconducting magnet 10 using a superconducting coil is completely immersed in liquid helium and fixed in close proximity to the partition wall 6.

Between the partition wall 6 and the liquid helium tank 3, there is a
As shown in part A) of the figure, the radiation shield thin plates 7 are arranged very close to each other with a space between them. The liquid helium tank 3 is surrounded by a liquid nitrogen temperature section which is an intermediate temperature section, and the liquid nitrogen temperature section includes the liquid nitrogen tank 2, the radiation solder thin plate 7, the radiation shield thick plate 20, and the built-up part 4. ,
It is composed of a radiation shield plate 19. absolute temperature 77
The liquid nitrogen tank 2 is thermally coupled to the radiation shield thin plate 7, the radiation shield thick plate 20, the built-up portion 4, and the radiation shield plate 19 made of aluminum or the like having good thermal conductivity. The liquid nitrogen temperature section is maintained at 77K. In addition, these radiation shield thin plates 7 and radiation shield thick plates 2
0, the built-up portion 4 and the radiation shield plate 19 have a function of shielding the radiant heat that has entered from the case 1, and do not allow the radiant heat to pass through to the liquid helium tank 3 inside.

12 is a gas nitrogen exhaust pipe for discharging nitrogen gas generated by evaporation in the liquid nitrogen tank 2. This gas nitrogen exhaust pipe 12 is in contact with the outside of the radiation shield plate 20,
It is wound in a coil shape from the farthest position of the liquid nitrogen tank 2 to the vicinity of the liquid nitrogen tank 2. In order to make the temperature distribution uniform in the liquid nitrogen temperature section, the winding method is such that the distance between the gas nitrogen exhaust pipes 12 is wide at the farthest position of the liquid nitrogen tank 2, as shown in FIG. As you get closer to , the distance between them is gradually narrowed.

A super insulation 11 for heat insulation is provided between the liquid helium tank 3 and the liquid nitrogen tank 2. For the super insulation 11, for example, glass fibers surrounded by aluminum foil are used to reflect radiant heat.

Next, the cooling support structure of the superconducting maintenance temperature section 28 will be explained.

A liquid nitrogen tank 2 is present on the inner surface of the two side walls of the case 1 of the horizontal superconducting motor. 23, it is fixedly supported to the case 1 in a heat-insulating manner. For example, the heat insulating support material 21 is composed of spokes,
One end of the spoke is fixed by tension to a heat insulating support 23 which is spline-coupled to the case 1, and the other end of the spoke is fixed to a circumferential flange provided in the liquid nitrogen tank 2 in the radial direction of the spoke. Since it is fixed by a tensile force, the liquid nitrogen tank 2 is ultimately suspended and fixed to the case 1 by the spokes.

Furthermore, a spoke, which is another heat insulating support material 21, is fixed to the circumferential collar of the liquid nitrogen tank 2 facing the liquid helium tank 3, and a liquid helium temperature section containing the superconducting coil 10 is suspended. I support it lower.

Next, in the liquid nitrogen temperature section inside the other side wall of case I, there is a built-up part 4 and a radiation shield plate 19 following it, and the built-up part 4 is connected to the heat insulation provided outside the liquid nitrogen temperature part. It is fixedly supported to the case 1 in a heat-insulating manner by the support member 5 and the heat-insulating support base 22. The heat insulating support base 22 is fastened and fixed by the side wall of the case 1 and the partition wall 6 in a sandwich-like manner.

Further, a spoke, which is another heat insulating support material 5, is fixed to the side of the built-up portion 4 facing the liquid helium temperature section, and the spoke suspends and supports the liquid helium temperature section containing the superconducting coil 10. are doing.

The liquid nitrogen tank 2 and the built-up portion 4 are thermally coupled by a radiation shield thick plate 20 that is disposed facing each other along the circumferential surface of the case 1. The built-up portion 4 is welded or used to connect the radiation shield thick plate 20.

Liquid helium transfer port 2 is located at the top of one side of the side wall of case 1.
4, and a liquid nitrogen transfer port 25 are provided. Liquid helium is supplied from a liquid helium tank provided outside the superconducting motor through the liquid helium transfer port 24 to keep the level of the liquid helium in the liquid helium tank 3 inside the motor at a constant level. Further, even if the liquid helium tank is not provided outside the motor, gasified helium may be cooled back to liquid by a refrigerator provided outside, and liquid helium may be supplied from the liquid helium transfer port 24. As described above, the liquid helium tank requires some kind of liquid helium supply means for maintaining the liquid helium level.

Furthermore, a vacuum outlet 26 is provided at the top of the cylindrical outer peripheral surface of the case 1.

Although the above configuration describes an embodiment in which the liquid nitrogen tank 2 is arranged only on one side, the liquid nitrogen tank may also be arranged on both sides. In that case, the gas nitrogen exhaust pipe 12 Start wrapping near the center of the shield plank.

In addition, in this example, liquid helium was used to maintain the superconducting temperature, and liquid nitrogen was used to cool the intermediate temperature section to insulate the liquid helium, or depending on the critical temperature of the superconducting material used, these coolants Needless to say, the type can be changed in various ways.

It should be noted that the present invention is not limited to the above embodiments, and various modifications can be made based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

(Effects of the Invention) As described above in detail, according to the present invention, the piping discharged from a tank containing a liquid medium for intermediate temperature cooling is placed on a plate having a radiation shielding function farthest from the tank. Since it is wound into a coil from one position to another, it has a compact structure, and the intermediate temperature section has a uniform temperature distribution throughout, making it possible to form an adiabatic structure. .

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a horizontal cross-sectional view in the axial direction of a horizontal superconducting motor according to an embodiment of the present invention, FIG. 2 is a diagram similarly showing a vertical cross-sectional view in the axial direction, and FIG. FIG. 4 is an enlarged view of A in FIG. 1, FIG. 4 is a sectional view taken along line BB in FIG. 1, and FIGS. 5 and 6 are diagrams showing conceptual diagrams of the intermediate temperature section of the present invention. 1 case, 2 liquid nitrogen tank, 3 liquid helium tank, 4
Overlay part, 5-insulation support material, 7 radiation shield thin plate,
8 rotor, ]0 superconducting coil, 12-gas nitrogen exhaust pipe, l 9-1ai + injection noord plate, 20-@ injection shield thick plate. Patent Applicant: Aisin ADA Co., Ltd. Agent: Yoshihiko Koraihi (2 others), Figure 2, Figure 3, Figure 4

Claims (1)

[Claims] (1) In a superconducting motor having a superconducting coil in the stator section, a superconducting maintaining temperature section having the superconducting coil is surrounded by an intermediate temperature section including a plate having a radiation shielding function, and the plate having a radiation shielding function is an intermediate temperature section. An exhaust pipe is thermally coupled to a tank containing a liquid medium for maintaining the temperature and is in contact with the plate having a radiation shielding function for exhausting evaporative gas generated in the tank containing the liquid medium. A superconducting motor characterized in that the superconducting motor is wound into a coil shape, with the winding starting at a position farthest from the tank containing the liquid medium and winding ending near the tank containing the liquid medium.