A hybrid superconducting disc motor with superconducting rotor

Abstract

The invention discloses a hybrid superconducting disc motor with a superconducting rotor. The stator comprises a stator support and a stator core; the rotor comprises a rotor shaft and a back iron shell; the rotor back iron shell is coaxially sleeved on the hollow rotor shaft, and the rotor back iron shell comprises a copper heat-conducting component; the rotor back iron shell comprises a hollow shell and an end plate; the hollow shell and the end plate both comprise an axial hole for sealing and assembling the rotor shaft; the copper heat-conducting component comprises a columnar end, which is arranged in a circular ring distribution along the rotation direction of the rotor; an annular bottom located at the root of the columnar end and used for connecting a plurality of columnar ends in series; a through hole for matching the columnar end is comprised on the front end surface of the hollow shell; a superconducting coil is wound on the columnar end extending out of the hollow shell; a distributed cooling gas / liquid circuit is comprised in the cavity formed in the rotor back iron shell; the stator core comprises a wedge-shaped iron core body formed by stacking silicon steel layers; a copper wire coil is wound between the two ends of the wedge-shaped iron core body as a winding.

Description

Technical Field

[0001] The invention relates to the technical field of motor superconductivity, and in particular to a hybrid superconducting disc motor with a superconducting rotor. Background Art

[0002] The electric machine typically includes a cylindrical rotor mounted to rotate about or within a cooperating stator. That is, the electric machine may have a generally cylindrical inner rotor mounted within an outer stator, or a cylindrical outer rotor mounted about an inner stator. In a superconducting electric machine, the stator and / or the rotor may include a plurality of superconducting field coils mounted on a field coil support structure so as to form a surface generally adjacent to but spaced apart from a surface of the other of the stator or the rotor.

[0003] There are a number of problems that must be overcome in such rotor and stator constructions. First, the superconducting field coils and field coil support structure must be maintained at cryogenic temperatures during operation. Conversely, it is preferred to maintain the mounting frame to which the field coil support structure is mounted as close to ambient temperature as possible to allow the rotor or stator to be connected to other devices or components that operate at ambient temperatures. Therefore, there is a need for an improved rotor and stator construction that provides very good thermal insulation between the field coil support structure and the mounting frame for the field coil support structure. Summary of the invention

[0004] A technical solution provided by the present invention is a hybrid superconducting disc motor with a superconducting rotor, which solves:

[0005] 1. The permanent magnets of the motor rotor generate losses (in the form of heat energy), which causes the temperature to rise during the operation of the motor. Although the use of superconducting materials will cause eddy current losses, the low resistance characteristics will greatly reduce the copper loss of the motor.

[0006] 2. The eddy current loss of the magnetic steel on the rotor disk causes the rotor temperature to rise. If the temperature is too high, it may cause the magnetic steel to demagnetize.

[0007] The technical solution of the present invention is: for the disc-type superconducting motor, the rotor part adopts YBCO superconductor, and the stator part still adopts the traditional copper wire coil.

[0008] The stator support is implemented as a disc-shaped support body with a central hole penetrating in the axial direction. A series of grooves are provided on the inner ring surface of the support body, including: an embedding groove for embedding the stator core. The embedding groove is U-shaped, and multiple embedding grooves are evenly arranged along the rotation direction of the inner ring of the support body.

[0009] The stator core is mainly a wedge-shaped core body, which is made of silicon steel laminated, bonded and welded. Because it is suitable for disc motors, the wedge-shaped core body is cut and designed according to the indexing of the disc. That is, the wedge-shaped core body is I-shaped, with pole shoes at both ends and the two sides cut into inclined surfaces. Copper wire coils are wound between the pole shoes at both ends of the wedge-shaped core body.

[0010] The rotor superconducting structure includes a rotor shaft, a rotor back iron shell, a copper heat-conducting component, and an HTS high-temperature superconducting coil. The rotor shaft is a hollow shaft, and a rotor back iron shell is coaxially sleeved on the rotor shaft. Therefore, direct current is passed through the superconducting coil in the rotor to generate a constant electromagnetic field under an ideal state. At this time, the superconducting winding is reduced to below the critical temperature and reaches a superconducting state. Through the low resistance characteristics in the superconducting state, a steady-state magnetic field is generated with a constant circular current to replace the permanent magnet. In the stator, superconducting coils are used to replace traditional copper coils.

[0011] The rotor back iron shell includes a hollow shell in the shape of a disc and an end plate sealed and assembled at the rear end of the hollow shell. The end plate is encapsulated at the rear end of the hollow shell to form a cavity inside the rotor back iron shell.

[0012] The rotor back iron shell is mounted on the rotor shaft, so the center of the hollow shell and the end plate includes an axial hole for sealing and assembling the rotor shaft. The rotor shaft is in the shape of a stepped shaft, so the structural assembly can be achieved by matching the corresponding shaft diameter with the corresponding shaft hole on the rotor back iron shell. It should be noted that in order to ensure the airtightness of the cavity, a sealing ring is added at the assembly point of the rotor shaft and the corresponding shaft hole, which can effectively ensure the sealing effect of the cavity.

[0013] The copper heat-conducting component is installed in the cavity. The copper heat-conducting component includes a plurality of columnar ends parallel to the rotor axis. The columnar ends are arranged in a circular ring along the rotor rotation direction. A connecting portion extends from the root of the columnar end to connect adjacent columnar ends in series. The connecting portions are continuously connected in series to form an annular bottom that connects all columnar ends in series.

[0014] The front end surface of the hollow shell includes a through hole for matching the cylindrical end, and the through hole is distributed in a circular trajectory corresponding to the columnar end. The copper heat-conducting component is assembled by inserting the columnar end into the through hole, and the columnar end extending out of the hollow shell is wound with a YBCO superconducting coil. A constant DC current is passed through the YBCO superconducting coil, and the superconducting low resistance state will cause the current to circle in the racetrack winding all the time, so that it can generate a constant electromagnetic field under an ideal state, which is used to replace the permanent magnet magnetic steel.

[0015] The cavity formed in the rotor back iron shell includes a distributed cooling gas / liquid loop. The cooling liquid gas introduced into the distributed cooling gas / liquid loop can be selected as: gas / liquid nitrogen, gas / liquid helium or other low-temperature coolants.

[0016] The advantages of the present invention are:

[0017] 1. The rotor part uses YBCO superconducting coils instead of permanent magnets, which can improve the temperature rise of the rotor part and avoid the demagnetization of the permanent magnets caused by excessive rotor temperature. Compared with traditional motors, the output torque is greater.

[0018] 2. The cooling circuit is simpler, and superconducting cooling is performed through the built-in cavity, and its cooling effect is more prominent.

[0019] 3. Compared with traditional motors, it has lower losses and can avoid temperature rise problems, thereby improving the overall performance of the motor; compared with full superconductors, it has low costs and can adapt to working conditions where power requirements are greater than traditional motors but smaller than full superconductors. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0021] Figure 1 This is the structural explosion diagram of the hybrid superconducting disc motor;

[0022] Figure 2 This is an exploded view of the rotor superconducting structure;

[0023] Figure 3 This is the assembly diagram of the double-sided rotor superconducting structure;

[0024] Figure 4 It is a cross-sectional view of the double-sided rotor superconducting structure;

[0025] Among them, 1. hollow shell; 2. end plate; 3. copper column heat conduction structure; 4. copper terminal; 5. sealing ring; 6. superconducting coil; 7. hollow shaft; 8. wedge-shaped iron core; 9. copper wire coil. DETAILED DESCRIPTION

[0026] Example 1

[0027] The rotor part uses YBCO superconductor, while the stator part still uses traditional copper wire coils.

[0028] The structure of the rotor is shown in the figure, which includes: a hollow shell 1, an end plate 2, a copper column heat-conducting structure 3 (for cooling and fixing the rotor superconducting coil) and a sealing ring 5 which are mounted on a hollow shaft 7.

[0029] First, place the copper column heat-conducting structure 3 (i.e., the copper heat-conducting component) into the rotor back iron shell, and the copper terminal 4 extends out of the rotor back iron shell, and then install the sealing ring 5 and the end plate 2, so that a cavity is formed inside the rotor back iron shell to accommodate the distributed cooling gas / liquid circuit. The upper and lower surfaces of the formed cavity are made of materials with strong structure and low magnetic permeability such as austenitic steel / duralumin / titanium alloy, so the formed cavity has a high structural strength.

[0030] Since the cavity can ensure its airtightness, a dry powder refrigerator can be used to directly cool the cavity of the hollow shaft 7, while the rotor part transfers heat through the copper terminal, and the distributed cooling gas / liquid circuit can also directly and effectively cool the superconducting coil 6 of the rotor.

[0031] A constant direct current is passed through the superconducting coil 6, and the superconducting low resistance state causes the current to continuously circle in the racetrack winding, so as to generate a constant electromagnetic field under an ideal state, which is used to replace the permanent magnet steel.

[0032] The rotating shaft adopts a hollow shaft structure, and the rotor part can be maintained through the hollow shaft 7 (such as passing liquid nitrogen or passing current to the superconducting coil).

[0033] Cooling system in the structure of superconducting rotor:

[0034] The distributed cooling gas / liquid loop can also directly and effectively cool the superconducting coils 6 of the rotor. Since the cavity can ensure its airtightness, the rotor part can transfer heat through the copper terminals.

[0035] The structure of the stator includes a stator bracket and a stator core.

[0036] The stator support is implemented as a disc-shaped support body with a central hole penetrating in the axial direction. A series of grooves are provided on the inner ring surface of the support body, including: an embedding groove for embedding the stator core. The embedding groove is U-shaped, and multiple embedding grooves are evenly arranged along the rotation direction of the inner ring of the support body.

[0037] The stator core is mainly a wedge-shaped core body 8, which is made of silicon steel laminated, bonded and welded. Because it is suitable for disc motors, the wedge-shaped core body is cut and designed according to the indexing of the disc. That is, the wedge-shaped core body 8 is I-shaped, with pole shoes at both ends and the two side surfaces cut into inclined surfaces. A copper wire coil 9 is wound between the pole shoes at both ends of the wedge-shaped core body.

[0038] Embodiment 2:

[0039] The stator part of this solution uses 18 stator cores and traditional copper wire windings. Since the superconducting material is relatively fragile, the rotor part uses a coil wound by superconducting tape to replace the permanent magnet. The size of the superconducting coil is larger than that of the permanent magnet. Finally, the rotor part of this solution uses 12 poles. At the same time, the cooling structure of the rotor uses a combination of the rotor back iron shell cavity and the hollow shaft.

[0040] The embodiments of the present invention are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A hybrid superconducting disc motor with a superconducting rotor, comprising: stator and rotor; The stator includes: a stator bracket, a stator core embedded in the stator bracket; the rotor includes: a rotor shaft penetrating the stator axial direction, and rotor back iron shells on both sides sleeved on the rotor shaft; the characteristics are: A rotor back iron shell is coaxially sleeved on the hollow rotor shaft, and the rotor back iron shell includes a copper heat-conducting component; The rotor back iron shell includes a hollow shell in the shape of a disk and an end plate sealably mounted on the rear end of the hollow shell; both the hollow shell and the end plate include an axial hole for sealably mounting the rotor shaft; The copper heat-conducting component includes a columnar end parallel to the rotor axis, the columnar ends are arranged in a circular ring along the rotor rotation direction; and an annular bottom located at the root of the columnar end for connecting multiple columnar ends in series; The front end surface of the hollow shell includes a through hole for matching the columnar end; the columnar end extending out of the hollow shell is wound with a superconducting coil; A distributed cooling gas / liquid circuit is included in a cavity formed in the rotor back iron housing; The stator core comprises a wedge-shaped core body formed by stacking silicon steel layers; a copper wire coil is wound between pole shoes at both ends of the wedge-shaped core body as a winding.

2. The hybrid superconducting disc motor with superconducting rotor according to claim 1, characterized in that: The superconducting coil comprises HTS high temperature superconducting material.

3. The hybrid superconducting disc motor with superconducting rotor according to claim 1, characterized in that: The hollow rotor shaft is in a multi-step shape, and the matching parts between the hollow rotor shaft, the rotor back iron shell and the end plate all include sealing rings.

4. The hybrid superconducting disc motor with superconducting rotor according to claim 1, characterized in that: The hollow rotor shaft is assembled with the keyway on the end plate via a connecting key.

5. The hybrid superconducting disc motor with superconducting rotor according to claim 1, characterized in that: The surface material of the cavity formed in the rotor back iron shell includes austenitic steel, hard aluminum, and titanium alloy.

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