Superconducting motor rotor and motor rotor cryogenic system

Abstract

The application discloses a superconducting motor rotor and a motor rotor low-temperature system. The superconducting motor rotor comprises an outer frame, a support framework, a superconducting magnet and an intermediate shaft. The inner part of the outer frame is formed with a vacuum cavity, the support framework is located in the vacuum cavity, the superconducting magnet is connected to the support framework, and the intermediate shaft is fixedly connected to the outer frame and located on the inner side of the support framework, thereby forming a rotor structure of the superconducting motor. The cooling assembly can realize the cooling of the superconducting magnet by cooling the support framework, so that the rotor is in a low-temperature environment. Since the intermediate shaft is internally provided with a mounting cavity, the mounting cavity can be used for mounting the low-temperature assembly of the cooling rotor. The low-temperature assembly is mounted in the inner part of the rotor, so that the land area of the external low-temperature system component can be effectively reduced. The vacuum cavity formed in the inner part of the outer frame can be heat-insulated, thereby creating a good low-temperature environment for the rotor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of superconducting motor, in particular to a superconducting motor rotor and a motor rotor low-temperature system. BACKGROUND

[0002] A superconducting motor is an advanced motor using a superconducting magnet for excitation. The superconducting magnet has a resistance close to zero at low temperature, and can generate a very strong magnetic field in a limited space. Compared with a conventional motor, the superconducting motor has a higher torque density, and has the advantages of small size, light weight, high efficiency, etc.

[0003] However, the superconducting motor needs to transmit low-temperature cold energy to the superconducting magnet in the rotor through a low-temperature system to maintain the superconducting state of the superconducting magnet. For example, a high-temperature superconducting motor rotor low-temperature cooling system disclosed in CN109525069A transmits low-temperature neon gas to the inside of the rotor through a magnetic fluid sealing device to achieve low temperature in the inside of the rotor.

[0004] In the prior art, the low-temperature system of the superconducting motor is generally arranged outside the superconducting motor, and the low-temperature coolant is transmitted to the rotor through a magnetic fluid rotary sealing device. Since the low-temperature system needs a certain floor area, the technical advantages of the superconducting motor compared with the conventional motor are weakened. SUMMARY

[0005] The present application aims to overcome the above technical deficiencies and provide a superconducting motor rotor and a motor rotor low-temperature system to solve the technical problem of a large floor area of the superconducting motor rotor low-temperature system in the prior art.

[0006] To achieve the above technical purpose, the present application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a superconducting motor rotor, comprising:

[0008] an outer frame forming a vacuum cavity inside;

[0009] a support framework located in the vacuum cavity;

[0010] a superconducting magnet connected to the support framework; and

[0011] an intermediate shaft located on the inner side of the support framework and fixedly connected to the outer frame, the intermediate shaft being provided with an installation cavity inside, and the installation cavity being used for installing a cooling assembly.

[0012] In some embodiments, the inner side of the outer frame is connected to the intermediate shaft, the installation cavity is provided with a support frame inside, the support frame is provided with an installation hole, the installation hole is used for installing the cooling assembly, and the cooling assembly, the intermediate shaft and the outer frame are enclosed to form the vacuum cavity.

[0013] In a second aspect, the present application provides a motor rotor low-temperature system, comprising:

[0014] the superconducting motor rotor; and

[0015] a cooling assembly installed in the installation cavity, the cooling assembly being connected to the support frame through a pipeline, and being configured to cool the support frame by inputting a low-temperature medium into the support frame.

[0016] In some embodiments, the low-temperature system further comprises a medium supply unit connected to the cooling assembly, and configured to supply a normal-temperature medium to the cooling assembly and receive the normal-temperature medium output by the cooling assembly.

[0017] In some embodiments, the cooling assembly comprises a counterflow heat exchanger and an expander, the expander being connected to the counterflow heat exchanger and the support frame, and being configured to receive the sub-low-temperature medium from the counterflow heat exchanger and form a low-temperature medium, and to deliver the formed low-temperature medium to the support frame, the counterflow heat exchanger being connected to the support frame and the medium supply unit, and being configured to receive the normal-temperature medium input by the medium supply unit and the low-temperature medium after the support frame, and to form the sub-low-temperature medium by exchanging heat between the low-temperature medium and the normal-temperature medium.

[0018] In some embodiments, the medium supply unit comprises a compressor, a cooler and a magnetic fluid seal, the magnetic fluid seal being connected to the intermediate shaft and the counterflow heat exchanger, the cooler being connected to the magnetic fluid seal, and the compressor being connected to the cooler, the compressor, the cooler, the magnetic fluid seal, the counterflow heat exchanger, the expander and the support frame being configured to circulate the medium.

[0019] In some embodiments, the magnetic fluid seal comprises a rotating shaft, a sleeve, a plurality of permanent magnets and a plurality of magnetic poles, the rotating shaft being fixedly connected to the intermediate shaft, the sleeve being circumferentially arranged around the rotating shaft and being rotatably connected to the rotating shaft, each of the magnetic poles being arranged on the inner side of the sleeve and forming a filling cavity filled with magnetic fluid between the rotating shaft and the magnetic pole, at least one medium input cavity and at least one medium output cavity being formed between the magnetic poles, the medium input cavity and the medium output cavity being configured to input and output the medium, respectively, each of the permanent magnets being arranged between the magnetic poles, and the adjacent permanent magnets having opposite magnetic properties.

[0020] In some embodiments, the rotating shaft is internally provided with an input flow channel and an output flow channel, the output flow channel and the input flow channel being respectively connected to the input interface and the output interface of the counterflow heat exchanger.

[0021] In some embodiments, the magnetic fluid seal further comprises a partition ring, an input pipe and an output pipe, the partition ring is arranged in the medium input cavity and the medium output cavity, and the input pipe and the output pipe pass through the partition ring and respectively communicate with the medium input cavity and the medium output cavity.

[0022] In some embodiments, a slip ring and a carbon brush can be arranged on the rotating shaft, a cable channel is arranged inside the rotating shaft, the slip ring leads out a cable, the cable passes through the cable channel and provides required power supply for the expander.

[0023] Compared with the prior art, the superconducting motor rotor provided by the application comprises an outer frame, a support framework, a superconducting magnet and an intermediate shaft, a vacuum cavity is formed in the inner part of the outer frame, the support framework is located in the vacuum cavity, the superconducting magnet is connected to the support framework, the intermediate shaft is located inside the support framework and is fixedly connected to the outer frame, forming a rotor structure of the superconducting motor, and the cooling assembly can realize cooling of the superconducting magnet by cooling the support framework, so that the rotor is in a low-temperature environment, the intermediate shaft is internally provided with a mounting cavity, the mounting cavity can be used for mounting the low-temperature assembly for cooling the rotor, the low-temperature assembly is arranged inside the rotor, so that the area occupied by the external low-temperature system components can be effectively reduced, the vacuum cavity formed in the inner part of the outer frame can be heat-insulated, thereby creating a good low-temperature environment for the rotor. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a structural schematic diagram of a low-temperature system of a motor rotor provided by an embodiment of the application;

[0025] Figure 2 is a structural schematic diagram of a magnetic fluid seal provided by an embodiment of the application.

[0026] Reference signs in the drawings:

[0027] 10 - outer frame 11 - vacuum cavity 20 - support framework

[0028] 12 - support frame 13 - iron core 22 - magnet support frame

[0029] 30 - superconducting magnet 40 - intermediate shaft 41 - mounting cavity

[0030] 42 - support frame 50 - cooling assembly 51 - counterflow heat exchanger

[0031] 52 - expander 60 - medium supply unit 61 - compressor

[0032] 62 - cooler 63 - magnetic fluid seal 631 - rotating shaft

[0033] 632 - outer sleeve 633 - permanent magnet 634 - magnetic pole

[0034] 635 - spacer ring 636 - input pipe 637 - output pipe

[0035] 638 - slip ring 639 - carbon brush 6311 - input flow channel

[0036] 6312 - output flow channel 6313 - cable passage 6341 - medium input cavity

[0037] 6342 - medium output cavity. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0039] In order to solve the technical problem of large floor area of the superconducting motor rotor cryogenic system in the prior art, the present application provides a superconducting motor rotor and a motor rotor cryogenic system to reduce the floor area of the motor rotor cryogenic system.

[0040] The superconducting motor rotor provided by the present application comprises an outer frame 10, a support framework 20, a superconducting magnet 30 and an intermediate shaft 40, the inside of the outer frame 10 forms a vacuum cavity 11, the support framework 20 is located in the vacuum cavity 11, the superconducting magnet 30 is connected to the support framework 20, and the intermediate shaft 40 is located on the inner side of the support framework 20 and is fixedly connected to the outer frame 10. Figure 1 The inside of the intermediate shaft 40 is provided with a mounting cavity 41 for mounting a cooling assembly 50 for cooling the support framework 20.

[0041] Specifically, the superconducting motor rotor is formed by arranging the outer frame 10, the support framework 20, the superconducting magnet 30 and the intermediate shaft 40, the inside of the outer frame 10 forms the vacuum cavity 11, the support framework 20 is located in the vacuum cavity 11, the superconducting magnet 30 is connected to the support framework 20, the intermediate shaft 40 is located on the inner side of the support framework 20 and is fixedly connected to the outer frame 10, forming a rotor structure of the superconducting motor, the cooling assembly 50 can cool the superconducting magnet 30 by cooling the support framework 20, so that the rotor is in a low-temperature environment, the inside of the intermediate shaft 40 is provided with the mounting cavity 41 for mounting the low-temperature assembly for cooling the rotor, the low-temperature assembly is arranged in the inside of the rotor, which can effectively reduce the floor area of the external low-temperature system components, and the vacuum cavity 11 formed in the inside of the outer frame 10 can be insulated, thereby creating a good low-temperature environment for the rotor.

[0042] In the present embodiment, the outer frame 10 comprises a middle hole cylinder and sealing end plate structures fixed to both ends of the cylinder, the intermediate shaft 40 penetrates the sealing end plate and is fixedly connected to the sealing end plate.

[0043] In the embodiment, as shown in Figure 1 The support skeleton 20 comprises a support and a magnet support frame 22, the inner side of the support is fixed to the intermediate shaft 40, the magnet support frame 22 is fixed to the outer side of the support, the superconducting magnet 30 is fixed to the magnet support frame 22, the inner part of the magnet support frame 22 is provided with a fluid channel, when the low-temperature medium flows through the fluid channel, the magnet support frame 22 will be cooled, then through the heat exchange between the magnet support frame 22 and the superconducting magnet 30, the cooling of the superconducting magnet 30 is realized. Through the above arrangement, the vacuum cavity 11 can be formed in the rotor, so that the structure of the low-temperature system is not too complex and a large space is not occupied due to the arrangement of the vacuum cavity 11, and through the heat insulation of the vacuum cavity 11, only the magnet support frame 22 and the superconducting magnet 30 in the rotor are in the low-temperature environment, and the components other than the magnet support frame 22 and the superconducting magnet 30 are in the normal-temperature environment.

[0044] In the embodiment, the components other than the magnet support frame 22 and the superconducting magnet 30 can be wrapped with a heat insulation layer to ensure that the components other than the magnet support frame 22 and the superconducting magnet 30 maintain the normal temperature.

[0045] In the embodiment, the inner part of the peripheral frame 10 is further provided with a support frame 12 and an iron core 13, the support frame 12 is fixed to the intermediate shaft 40, the iron core 13 is fixed to the support frame 12 and located on the inner side of the magnet support frame 22 and spaced from the magnet support frame 22, the support and the magnet support frame 22 form a low-temperature environment through the low-temperature medium, and the iron core 13 forms a normal-temperature environment through the spacing from the magnet support frame 22.

[0046] In one of the embodiments, as shown in Figure 1 The inner side of the peripheral frame 10 is connected to the intermediate shaft 40, the inner part of the mounting cavity 41 is provided with a support frame 42, the support frame 42 is provided with a mounting hole, the mounting hole is used for mounting the cooling assembly 50 and making the cooling assembly 50, the intermediate shaft 40 and the peripheral frame 10 form the vacuum cavity 11. Specifically, the cooling assembly 50 can be installed and fastened to the support frame 42 through the mounting hole of the support frame 42, and a closed vacuum structure can be formed on the inner side of the intermediate shaft 40. Since the structure between the intermediate shaft 40 and the peripheral frame 10 is also closed, the inner side of the entire rotor and the inner part of the intermediate shaft 40 form a communicated vacuum cavity.

[0047] In the embodiment, the sealing end plate of the peripheral frame 10 is fixed to the intermediate shaft 40.

[0048] The embodiment of the application further provides a low-temperature system of a motor rotor, as shown in Figure 1 The low-temperature system of the motor rotor comprises the superconducting motor rotor and the cooling assembly 50, the cooling assembly 50 is installed in the mounting cavity 41, and the cooling assembly 50 is connected to the support skeleton 20 through a pipeline and used for cooling the support skeleton 20 by inputting the low-temperature medium into the support skeleton 20.

[0049] Specifically, the motor rotor low-temperature system can form the cooling assembly 50 inside the rotor by installing the cooling assembly 50 in the installation cavity 41, so that the cooling assembly 50 can provide a low-temperature environment for the superconducting magnet 30 of the rotor while effectively reducing the space occupation of the low-temperature system and improving the compactness of the low-temperature system.

[0050] It can be understood that the cooling assembly 50 can be any cooling device capable of supplying low-temperature medium to the support framework 20.

[0051] In this embodiment, the medium is helium.

[0052] In one of the embodiments, as shown in Figure 1 the low-temperature system further comprises a medium supply unit 60 connected with the cooling assembly 50, for supplying normal-temperature medium to the cooling assembly 50 and receiving the normal-temperature medium output by the cooling assembly 50. Specifically, the normal-temperature medium is supplied to the cooling assembly 50 through the medium supply unit 60, and the normal-temperature medium is cooled to low-temperature medium by the cooling assembly 50 and then supplied to the support framework 20, so as to maintain the low-temperature environment of the support framework 20.

[0053] In this embodiment, the cooling assembly 50 cools the medium inside the rotor, so that the low-temperature system does not need to separately provide a cooling module for cooling the normal-temperature medium outside the rotor, thereby simplifying the structure of the medium supply unit 60 outside the rotor and reducing the floor area of the low-temperature system.

[0054] In one of the embodiments, as shown in Figure 1 the cooling assembly 50 comprises a counterflow heat exchanger 51 and an expander 52, the expander 52 is connected with the counterflow heat exchanger 51 and the support framework 20, for receiving the sub-low-temperature medium of the counterflow heat exchanger 51 and forming low-temperature medium, and delivering the formed low-temperature medium to the support framework 20, the counterflow heat exchanger 51 is connected with the support framework 20 and the medium supply unit 60, for receiving the normal-temperature medium input by the medium supply unit 60 and the low-temperature medium after the support framework 20, and exchanging heat between the low-temperature medium and the normal-temperature medium, so as to form the sub-low-temperature medium from the normal-temperature medium. Specifically, through the above arrangement, the normal-temperature medium supplied to the counterflow heat exchanger 51 by the external medium supply unit 60 exchanges heat with the low-temperature medium inside the counterflow heat exchanger 51, and is cooled to form the sub-low-temperature medium and is supplied to the expander 52, and the low-temperature medium is formed after being expanded by the expander 52, and the low-temperature medium is delivered from the expander 52 to the support framework 20, and exchanges heat with the support framework and then enters the counterflow heat exchanger 51, and the low-temperature medium exchanges heat with the normal-temperature medium supplied by the external medium supply unit 60 in the counterflow heat exchanger 51, to form the normal-temperature medium, and the formed normal-temperature medium is output for subsequent reuse, so as to form the low-temperature medium for manufacturing the low-temperature environment of the rotor.

[0055] In one embodiment, as shown in Figure 1 The medium supply unit 60 includes a compressor 61, a cooler 62, and a magnetic fluid seal 63, the magnetic fluid seal 63 is connected to the intermediate shaft 40 and connected with the counterflow heat exchanger 51, the cooler 62 is connected with the magnetic fluid seal 63, the compressor 61 is connected with the cooler 62, and the compressor 61, the cooler 62, the magnetic fluid seal 63, the counterflow heat exchanger 51, the expander 52, and the support frame 20 can supply medium circulation.

[0056] In this embodiment, the compressor 61 can use a multi-stage turbine compressor, and the helium gas at the outlet of each turbine compressor is cooled by the cooler 62 before entering the next stage turbine compressor. The compressor 61 can also use a screw compressor or other types of compressors.

[0057] Specifically, the medium supply unit 60 is provided as above, in the process of forming the rotor low-temperature environment, the high-pressure helium gas compressed by the compressor 61 is transmitted to the cooler 62 through the pipeline, and after cooling, it is transmitted to the refrigerant transmission rotary coupling through the pipeline, after static to rotary conversion, it is transmitted to the counterflow heat exchanger 51 of the rotor intermediate shaft 40, and after being cooled by the counterflow heat exchanger 51, it is expanded by the expander 52 to do work outside to form low-temperature helium gas, which is then transmitted to the internal passage of the magnet support frame 22 through the pipeline, and the magnet support frame 22 is cooled by convection, and the magnet support frame 22 cools the superconducting magnet 30 by conduction, and after passing out from the magnet support frame 22, it enters the counterflow heat exchanger 51 through the pipeline, and after heat exchange with the helium gas entering from the rotor rotary coupling, it returns to normal temperature to form normal-temperature helium gas, which is then returned to the suction port of the compressor 61 through the refrigerant transmission rotary coupling after rotary to static conversion, thus forming the circulation of the medium, and the medium creates the low-temperature environment of the rotor under the action of the circulation.

[0058] In one embodiment, as shown in Figure 2 The magnetic fluid seal 63 includes a rotating shaft 631, an outer sleeve 632, a plurality of permanent magnets 633, and a plurality of magnetic poles 634, the rotating shaft 631 is fixedly connected with the intermediate shaft 40, the outer sleeve 632 is circumferentially enclosed around the rotating shaft 631 and is rotatably connected with the rotating shaft 631, each magnetic pole 634 is arranged on the inner side of the outer sleeve 632 and forms a filling cavity filled with magnetic fluid between the rotating shaft 631, at least one medium input cavity 6341 and at least one medium output cavity 6342 are formed between the magnetic poles 634, the medium input cavity 6341 and the medium output cavity 6342 are respectively used for inputting or outputting medium, each permanent magnet 633 is arranged between each magnetic pole 634, and the magnetic properties of adjacent permanent magnets 633 are opposite.

[0059] Specifically, the rotating shaft 631, the outer sleeve 632, the plurality of permanent magnets 633 and the plurality of magnetic poles 634 form a magnetic fluid rotary seal, the medium input cavity 6341 and the medium output cavity 6342 are filled with medium, the medium input cavity 6341 is connected to the counter-flow heat exchanger 51 and the cooler 62, and the normal-temperature medium can be input to the counter-flow heat exchanger 51, and the medium output cavity 6342 is connected to the counter-flow heat exchanger 51 and the compressor 61, and the normal-temperature medium output by the counter-flow heat exchanger 51 can be input to the compressor 61.

[0060] In the embodiment, as shown in Figure 2 , the medium input cavity 6341 and the medium output cavity 6342 are both provided as one.

[0061] In the embodiment, as shown in Figure 2 , the magnetic pole 634 is provided with a tooth slot and a groove for mounting an O-ring, and the magnetic fluid is filled between the tooth slot and the rotating shaft 631.

[0062] In one of the embodiments, as shown in Figure 2 , the rotating shaft 631 is provided with an input flow channel 6311 and an output flow channel 6312, and the output flow channel 6312 and the input flow channel 6311 are connected to the input interface and the output interface of the counter-flow heat exchanger 51, respectively. Specifically, by forming the input flow channel 6311 and the output flow channel 6312 in the rotating shaft 631, the medium can be conveniently input from the magnetic fluid seal 63 to the counter-flow heat exchanger 51, and the medium can be conveniently input from the counter-flow heat exchanger 51 to the magnetic fluid seal 63, so that the medium is always inside the magnetic fluid seal 63, avoiding leakage of the medium, and simplifying the structure of the medium conveying pipeline.

[0063] In one of the embodiments, as shown in Figure 2 , the magnetic fluid seal 63 further comprises a partition ring 635, an input pipe 636 and an output pipe 637, the partition ring 635 is arranged in the medium input cavity 6341 and the medium output cavity 6342, and the input pipe 636 and the output pipe 637 pass through the partition ring 635 and are connected to the medium input cavity 6341 and the medium output cavity 6342, respectively. Specifically, the input pipe 636 and the output pipe 637 can respectively input and output the medium in the medium input cavity 6341 and the medium output cavity 6342, and the partition ring 635 can seal the input pipe 636 and the output pipe 637, avoiding leakage of the medium.

[0064] In the embodiment, the input pipe 636 is a high-pressure pipe, and the output pipe 637 is a low-pressure pipe.

[0065] In one of the embodiments, as shown in Figure 2The shaft 631 can be provided with a slip ring 638 and a carbon brush 639. The shaft 631 is provided with a cable passage 6313. The slip ring 638 leads out a cable. The cable is led out through the cable passage 6313 to provide power supply for the expander 52 and the compressor 61. Specifically, the slip ring 638 and the carbon brush 639 can provide power supply for the expander 52, so that the cryogenic system can provide a cryogenic environment for the rotor by using its own power supply, without the need of separately arranging a power supply device, thereby simplifying the structure of the cryogenic system. The cable passage 6313 can protect the cable and avoid exposure of the cable.

[0066] For better understanding of the present application, the following Figures 1 to 2 The technical scheme of the present application is described in detail as follows: in the process of forming the cryogenic environment for the rotor, the high-pressure helium compressed by the compressor 61 is transmitted to the cooler 62 through a pipeline, cooled, transmitted to the medium input cavity 6341 of the refrigerant transmission rotary coupling through the helium input pipe 636, converted from static to rotary, output through the output flow channel 6312 and transmitted to the counterflow heat exchanger 51 of the rotor intermediate shaft 40, cooled by the counterflow heat exchanger 51, expanded by the expander 52 to do work outside and form low-temperature helium, transmitted to the internal passage of the magnet support frame 22 through a pipeline, cooled the magnet support frame 12 by convection, cooled the superconducting magnet 30 by conduction, transmitted to the counterflow heat exchanger 51 through a pipeline after passing through the magnet support frame 12, returned to normal temperature after heat exchange with the helium entering from the rotor rotary coupling, formed normal-temperature helium, input to the input passage through the counterflow heat exchanger 51, then entered the medium output cavity 6342, rotated to the static conversion through the refrigerant transmission rotary coupling, returned to the suction port of the compressor 61 through the output pipe 637, so as to form the circulation of the medium and further create the cryogenic environment for the rotor.

[0067] The specific embodiments of the present application described above do not constitute a limitation on the protection scope of the present application. Any various other corresponding changes and modifications made according to the technical concept of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A motor rotor cryogenic system, characterized by, The application relates to a superconducting motor rotor and a cooling assembly. The superconducting motor rotor comprises: a peripheral frame forming a vacuum cavity inside; a support frame located in the vacuum cavity; a superconducting magnet connected to the support frame; and an intermediate shaft located inside the support frame and fixedly connected to the peripheral frame, the intermediate shaft being internally provided with a mounting cavity for mounting the cooling assembly. The inside of the peripheral frame is connected to the intermediate shaft, the mounting cavity is internally provided with a support frame, the support frame is provided with a mounting hole for mounting the cooling assembly, and the cooling assembly, the intermediate shaft and the peripheral frame are enclosed to form the vacuum cavity. The cooling assembly is mounted in the mounting cavity, and the cooling assembly is connected to the support frame through a pipeline for cooling the support frame by inputting low-temperature medium into the support frame. The low-temperature system further comprises a medium supply unit connected to the cooling assembly for supplying normal-temperature medium to the cooling assembly and receiving normal-temperature medium output by the cooling assembly. The cooling assembly comprises a counterflow heat exchanger and an expander connected to the counterflow heat exchanger and the support frame for receiving the secondary low-temperature medium of the counterflow heat exchanger and forming low-temperature medium and delivering the formed low-temperature medium to the support frame, the counterflow heat exchanger being connected to the support frame and the medium supply unit for receiving normal-temperature medium input by the medium supply unit and low-temperature medium after the support frame and exchanging heat between the low-temperature medium and the normal-temperature medium to form the secondary low-temperature medium.

2. The motor rotor cryogenic system of claim 1, wherein, The medium supply unit comprises a compressor, a cooler and a magnetic fluid seal connected to the intermediate shaft and connected to the counterflow heat exchanger, the cooler being connected to the magnetic fluid seal, the compressor being connected to the cooler, and the compressor, the cooler, the magnetic fluid seal, the counterflow heat exchanger, the expander and the support frame being capable of circulating medium.

3. The motor rotor cryogenic system of claim 2, wherein, The magnetic fluid seal comprises a rotating shaft fixedly connected to the intermediate shaft, a sleeve enclosing the circumference of the rotating shaft and rotationally connected to the rotating shaft, a plurality of magnetic poles arranged inside the sleeve and forming a filling cavity filled with magnetic fluid between the rotating shaft and the sleeve, at least one medium input cavity and at least one medium output cavity formed between the magnetic poles, each of the magnetic poles being arranged between the magnetic poles, and the magnetic poles adjacent to each other being opposite in magnetic property.

4. The motor rotor cryogenic system of claim 3, wherein, The rotating shaft is internally provided with an input flow channel and an output flow channel, and the output flow channel and the input flow channel are respectively connected to the input interface and the output interface of the counterflow heat exchanger.

5. The motor rotor cryogenic system of claim 3, wherein, The magnetic fluid seal further comprises a partition ring, an input pipe and an output pipe, the partition ring being arranged in the medium input cavity and the medium output cavity, and the input pipe and the output pipe penetrating the partition ring and being respectively connected to the medium input cavity and the medium output cavity.

6. The motor rotor cryogenic system of claim 3, wherein, The rotating shaft can be provided with a slip ring and a carbon brush, the rotating shaft is internally provided with a cable channel, the slip ring leads out a cable, and the cable is led out through the cable channel to provide required power supply for the expander.

Images