JPS6143949B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to electronic equipment, and more particularly to low temperature refrigerant cooled electronic equipment. It has applications in steam, heat or other power plants, as well as electric motors, generators and dynamos for ground and air vehicles.

A cryogenic fluid-cooled electronic machine utilizing standard circuitry has a rotor as a rotatable cryostart that is thermally and electromagnetically shielded and houses a superconducting field winding. . This winding is maintained in a superconducting state by a coolant that cools it to a temperature of 4.5㎓. Liquid helium is commonly used as the refrigerant. Proper selection of a low temperature system is important for superconducting windings. From a cooling machine or cryocontainer, liquid helium is supplied to the superconducting windings, cleaning them and then removing them from the machine. Thermal isolation is necessary to prevent heat fluxes transferred by convection and radiation and heat generated by winding reinforcement elements. Furthermore, low-temperature cooling electronic machines need to have high structural reliability. First, the rotor must receive the full torque from the superconducting windings and, in conjunction with this, must have sufficient mechanical rigidity to withstand the temperature stresses due to rotor vibration. be. Secondly, excessive heat fluxes to the superconducting windings, which are directly proportional to the cross-section of the reinforcing elements for securely mounting the windings, must be avoided.

Japanese Patent Application No. 52-142295 (filed on November 29, 1978) as a known technology related to low-temperature electronic equipment
In this case, the superconducting field winding is placed in the cavity of the rotor filled with coolant and is fixed to the rotor shaft, while the thermal-electromagnetic shield is placed in the exhaust space between the rotor and the casing. There is. This shield is cooled by coolant flowing from the rotor space through a coolant supply annular chamber located adjacent to the end wall of the rotor. In such machines, the cavity of the rotor, which is filled with refrigerant, is delimited by a shell whose end face is fixed to the rotor shaft.

A disadvantage of such machines is that the end walls of the rotor shell are rigidly connected to the rotor shaft and to the coolant supply annular chamber. When the shell 1 is mounted in this manner, a situation arises in which the heat generated in the shield is transferred along the end wall of the rotor shell to the liquid helium filling the rotor cavity. This also applies to the heat transferred from the shield to the superconducting windings by the shaft components. This is because the shield is rigidly connected to the shaft and this shaft is not provided with any means for removing heat.

Furthermore, with the start of the machine, a sudden temperature drop occurs and the rotor shell assumes a state characterized by complex stresses. The end walls of the shell are affected by axial forces resulting from differential expansion and contraction of the shell and rotor shaft in case of significant temperature drops.

On the one hand, there are also forces generated by the pressure of liquid helium and centrifugal forces acting on the shell and its end walls. Therefore, the end walls of the shell must be weighted to provide adequate stability of the shell and its base.

It is an object of the present invention to provide a low temperature refrigerant electronic machine in which the heat flux transferred by the rotor shaft to its superconducting field windings can be substantially reduced.

Another object of the present invention is to provide a low-temperature cooling electronic machine characterized by high operational stability.

A further object of the invention is to reduce the length of the rotor axis of a cooling electronic machine, thereby also making it possible to reduce the overall length of the machine.

According to the present invention, a superconducting field winding is arranged in a cavity of a rotor filled with a refrigerant, the winding is fixed to the shaft of the rotor, and the exhaust space between the rotor and the casing is provided with a thermal-electromagnetic field winding. The shield is cooled by refrigerant flowing from the cavity of the rotor to the shield via a refrigerant supply annular chamber located in the immediate vicinity of the end wall of the rotor. The face wall and the end wall of the chamber have necks spaced apart from each other to form a gap and adapted to the axis of the rotor, and the necks are interconnected at their edges; The gap between the necks communicates with the exhaust space between the rotor and the casing, and a cryocooled electronic device is provided in which two heat exchangers are arranged in the necks.

By configuring the rotor of an electronic machine in this manner, it is possible to reduce the heat infrastructure transmitted to the rotor by the shaft and generated within the shield as well as the heat infrastructure transmitted by the rotor shell.

Preferably, the heat exchanger is constituted by helical ribs located on the axis of the rotor and in the neck, and the helical ribs are located in spaced relation to each other, so that stresses occurring in the rotor shell are eliminated. be done.

Examples of the present invention will be described below with reference to the accompanying drawings.

The low temperature refrigeration electrical equipment according to the present invention includes a hollow rotor 1. The shaft 2 of the rotor 1 is the casing 5
It is rotatably mounted on a bearing 3 disposed within an end plate 4 of the. A stator winding 6 is provided on the inner surface of the casing 5. Note that the structure of this stator is not shown in detail. The space between the rotor 1 and the casing 5 is a vacuum, and the rotor 1 is thermally insulated. A rotatable vacuum retaining seal 7 is disposed within the end plate 4 to maintain the vacuum condition.

The hollow rotor 1 has a cylindrical shell 8, the end wall of which is close to the shaft 2. A superconducting field winding 9 is provided within the shell 8 and is fixed to the shaft 2 with an epoxy resin adhesive. The winding 9 is made of a material that behaves as a superconductor below a critical temperature. For this purpose, it is made from a Nb-Ti alloy stabilized by a pure copper matrix.

In the evacuated space between the casing 5 and the shell 8, a thermal-electromagnetic shield 10 is located annularly, consisting of a material that acts as a superconductor and has good electrical conductivity. The shield 10 is constructed as a cylinder with end walls.

The superconducting field winding 9 uses a coolant 11 (liquid helium)
is cooled down and brought into a superconducting state. The refrigerant 11 filling the cavity of the rotor 1 is circulated through a passage (not shown) in the winding 9.

In order to allow the refrigerant 11 to enter the cavity of the rotor 1, the shaft 2 is provided with a central hole drilled at one end thereof, in which a vacuum-maintained conduit 1 is inserted.
2 is placed. The refrigerant supply annular chamber 13 is connected to the rotor 1
The shield 10 is located very close to the end wall of the shield 10 and is spaced from the end wall by an exhaust gap, so that a passage for the refrigerant flowing into the shield 10 is formed. The end wall of the chamber 13 facing the end wall of the rotor 1 is the shield 1
0 end walls. This shield 1
0 has a passage 14 for refrigerant circulation. At both ends of the shaft 2 of the rotor 1 there are return passages 15 for the refrigerant 11, which communicate with the passage 14 and concentrators 16 provided at both ends of the shaft 2.

A heat exchanger 17 located at the end facing the shaft 2 is used to prevent a flux of heat into the cavity of the rotor 1.

FIG. 2 shows an enlarged view of the assembly location (assembly A) of the heat exchanger 17. End wall of shell 8 (second
) is provided with a neck 18 , while the end wall of the shield 10 is provided with a neck 19 . The neck 18 is located within a neck 19 surrounding the shaft 2. Neck 18,1
There is a gap between 9. The edges of the necks 18 and 19 are connected by a joint that can maintain a vacuum, and the gap between the necks 18 and 19 is between the rotor 1 and the casing 5.
and this gap is kept in a vacuum. The necks 18, 19 face the end of the shaft 2 on which they are located. A heat exchanger 17 is located within the necks 18,19.

FIG. 3 shows an alternative embodiment of assembly A of FIG. In this example, the necks 20, 21 extend from the end of the shaft 2 on which they are located, making it possible to reduce the length of the shaft 2.

Figure 4 shows the heat exchanger 17 connected to the helical rib 2 on the shaft 2.
2 and a helical rib 23 in the neck portion 18, and these helical ribs 22, 23 are arranged in a spaced relationship from each other.

The superconducting winding 9 (FIG. 1) of the device according to the invention is cooled as follows. A refrigerant 11 enters the cavity of the rotor 1 under a certain pressure from a refrigerator (not shown) via a conduit 12 and flows outside the winding 9 to cool it. The refrigerant 11 then leaves the cavity of the rotor 1 and passes through the heat exchanger 17 to cool the shaft 2 and the neck 18 of the shell 8. In passing through the heat exchanger 17, the refrigerant 11 passes through the annular chamber 13 and thus cools the end face of the shield 10 and then passes through the tube 14 to cool the shield 10. After leaving the shield 10, the refrigerant 11 is transferred to the shaft 2
It is cooled through a passage 15 and then fed to a gas concentrator 16. As described above, in this invention, by supplying the refrigerant that has passed through the field winding to the electromagnetic shield 10 via the heat exchanger, the inflow of heat from both the shaft part and the outer peripheral part is prevented, and the internal Low temperatures can be maintained more efficiently. Further, by providing a heat exchanger at the neck where the rotor 1 and the shield 10 are connected, thermal deformation occurring in the rotor can be absorbed at the neck. Furthermore, by adopting a structure in which the field winding is directly attached to the shaft 2, cooling efficiency can be improved and durability can be improved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of an electronic device according to the present invention, FIG. 2 is an enlarged view of the assembly A of FIG. 3 is an enlarged view of another embodiment of the assembly A of FIG. 1 according to the present invention, and FIG. 4 is a perspective view of the assembly A of FIG. 1 showing a heat exchanger according to the present invention. DESCRIPTION OF SYMBOLS 1... Rotor, 2... Axis of rotor 1, 5... Casing, 9... Superconducting winding, 10... Thermal-electromagnetic shield, 11... Refrigerant, 13... Refrigerant supply annular chamber, 17... ...Heat exchanger, 18, 19, 20,
21... Neck, 22, 23... Spiral rib.

Claims (1)

[Claims] 1. Each of the following components: a casing 5; a stator winding 6 disposed inside the casing 5 along its inner surface; a hollow rotor 1 rotatably disposed within the casing 5; The hollow rotor has opposite end walls, a shaft 2 carrying the hollow rotor 1, a superconducting field winding 9 arranged within the hollow rotor 1 and fixed to the shaft 2, between the casing 5 and the hollow rotor 1. a space which can be evacuated and is kept under vacuum, a thermal-electromagnetic shield 10 arranged in this space, the shield having an end wall supported by a shaft 2, a hollow rotor 1 and a thermal - coolant supplied to the electromagnetic shield 10; thermal - a plurality of passages 14 for the circulation of coolant provided in the shield for cooling the electromagnetic shield 10; An annular chamber 13 for circulation, which annular chamber 13 is connected to the hollow rotor 1
necks 18, 19 in the end walls of the hollow rotor and in the end walls of the thermal-electromagnetic shield, located in the immediate vicinity of the end walls of the hollow rotor and between the hollow rotor and the shaft; a gap communicating with the space of the hollow rotor and the shaft, the neck being coaxial with the hollow rotor and the shaft and spaced apart from each other to form said gap, and the neck having edges that are sealingly interconnected; A heat exchanger 17 provided in the neck part, which prevents the inflow flux of heat into the space of the hollow rotor;
3. A cryogenic cooling electronic machine consisting of: