A magnetic levitation active three-degree-of-freedom bearing, motor and compressor

Abstract

The application provides a magnetic suspension active three-degree-of-freedom bearing, motor and compressor, which comprises an axial magnetic bearing, a radial magnetic bearing and a bearing rotor, the axial magnetic bearing comprises first and second axial stators, the radial magnetic bearing comprises a radial stator, the radial stator is located at the outer periphery of the bearing rotor and can exert a radial electromagnetic force on the bearing rotor, the first and second axial stators can exert axial electromagnetic forces on the bearing rotor, at least part of the structure of the first axial stator is located radially outside the bearing rotor and radially inside the radial winding, at least part of the structure of the second axial stator is located radially outside the bearing rotor and radially inside the radial winding, so that the bias magnetic flux of the radial magnetic bearing is provided by the axial magnetic bearing. According to the application, the first and second axial stators provide bias magnetic circuits for the radial stator, the original structure such as a bias stator is omitted, the structure is more compact and simple, the process difficulty is reduced, the volume is reduced, and the assembly is easy.

Description

Technical Field

[0001] This invention relates to the field of magnetic levitation technology, specifically to a magnetic levitation active three-degree-of-freedom bearing, motor, and compressor. Background Technology

[0002] Magnetic bearings levitate the rotor shaft using electromagnetic force, keeping the shaft and stator in a non-contact state. This results in advantages such as no wear, high speed, high precision, and long lifespan. Magnetic bearings can be classified into three types based on their working principle: active magnetic bearings, passive magnetic bearings, and hybrid magnetic bearings.

[0003] The active three-degree-of-freedom magnetic bearing in patent CN110017330A, "An Axial and Radial Electromagnetic Magnetic Bearing", has a complex structure. It uses an E-shaped salient pole radially segmented stator to form a bias magnetic flux on the radial bearing. Its processing and manufacturing process is complex and assembly is difficult. There is magnetic leakage in the axial direction of the radial suspension winding.

[0004] Because existing magnetic levitation active three-degree-of-freedom bearings form the bias magnetic flux of the radial bearing by setting an bias stator, they have technical problems such as complex structure, large size, complicated process and difficult assembly. Therefore, this invention studies and designs a magnetic levitation active three-degree-of-freedom bearing, motor and compressor. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the existing magnetic levitation active three-degree-of-freedom bearing, which forms the bias magnetic flux of the radial bearing by setting an bias stator, resulting in a complex structure and large volume, thereby providing a magnetic levitation active three-degree-of-freedom bearing, motor and compressor.

[0006] To address the above problems, this invention provides a magnetically levitated active three-degree-of-freedom bearing, comprising:

[0007] An axial magnetic bearing, a radial magnetic bearing, and a bearing rotor are provided. Both the axial and radial magnetic bearings are sleeved on the outer circumference of a rotating shaft. The axial magnetic bearing includes a first axial stator and a second axial stator. The radial magnetic bearing includes a radial stator. The bearing rotor is sleeved on the outer circumference of the rotating shaft and can rotate with the shaft. The radial stator is located on the outer circumference of the bearing rotor and can apply a radial electromagnetic force to the bearing rotor. At least a portion of the structure of the first axial stator is located at one axial end of the bearing rotor along the axial direction of the rotating shaft, and at least a portion of the structure of the second axial stator is located at the other axial end. At the other axial end of the bearing rotor, the first axial stator and the second axial stator can apply axial electromagnetic force to the bearing rotor. The radial stator includes a radial core and a radial winding. The radial core is a ring structure and is sleeved on the radial outer side of the bearing rotor. At least a portion of the structure of the first axial stator is located on the radial outer side of the bearing rotor and on the radial inner side of the radial winding. At least a portion of the structure of the second axial stator is located on the radial outer side of the bearing rotor and on the radial inner side of the radial winding, such that the bias magnetic flux of the radial magnetic bearing is provided by the axial magnetic bearing.

[0008] In some embodiments, in the axial direction, the axial length of the radial core is less than the axial length of the bearing rotor, and the first axial end of the bearing rotor opposite to the first axial stator protrudes by a first predetermined distance than the third axial end of the radial core opposite to the first axial stator, such that the third axial end of the radial core is retracted relative to the first axial end to form a first space, and at least a portion of the structure of the first axial stator extends into the first space to be radially opposite to a portion of the structure of the bearing rotor.

[0009] The second axial end of the bearing rotor, which is opposite to the second axial stator, protrudes by a second predetermined distance from the fourth axial end of the radial core, which is opposite to the second axial stator, so that the fourth axial end of the radial core is retracted relative to the second axial end to form a second space, and at least a portion of the structure of the second axial stator extends into the second space so as to be radially opposite to a portion of the structure of the bearing rotor.

[0010] In some embodiments, the first axial stator includes a first axial core and a first axial winding. The first axial core is an annular structure, comprising a first main body, a first annular portion, and a second annular portion. The first main body is a disc structure with a first central hole through which the rotating shaft passes. The second annular portion is located radially outside the first annular portion. One end of the first annular portion is connected to the first main body, and the other end extends toward the bearing rotor to be opposite to the bearing rotor. One end of the second annular portion is connected to the first main body, and the other end extends toward the radial core to be opposite to the radial core and extends into the first space to form a first receiving groove between the radially outside of the first annular portion and the radially inside of the second annular portion. The first axial winding is disposed in the first receiving groove and wound around the outer periphery of the first annular portion.

[0011] In some embodiments, the first annular portion extends along the axial direction of the rotating shaft and is spaced a third preset distance from the bearing rotor to form a first axial working clearance; the second annular portion also extends along the axial direction of the rotating shaft and is spaced a fourth preset distance from the radial iron core to form a second axial working clearance.

[0012] The axial length of the second annular portion is greater than the axial length of the first annular portion, and the end of the second annular portion opposite to the radial iron core is located on the radial outer side of the bearing rotor, such that the end of the second annular portion opposite to the radial iron core is radially opposite to a portion of the structure of the bearing rotor.

[0013] In some embodiments, the second axial stator includes a second axial core and a second axial winding. The second axial core is an annular structure, comprising a second main body, a third annular portion, and a fourth annular portion. The second main body is a disc structure with a second central hole through which the rotating shaft passes. One end of the third annular portion is connected to the second main body, and the other end extends toward the bearing rotor to be opposite to the bearing rotor. One end of the fourth annular portion is connected to the second main body, and the other end extends toward the radial core to be opposite to the radial core. The fourth annular portion is located radially outside the third annular portion to form a second receiving groove between the radially outside the third annular portion and the radially inside the fourth annular portion. The second axial winding is disposed in the second receiving groove and wound around the outer periphery of the third annular portion.

[0014] In some embodiments, the third annular portion extends along the axial direction of the rotating shaft and is spaced a fifth preset distance from the bearing rotor to form a first axial working clearance; the fourth annular portion also extends along the axial direction of the rotating shaft and is spaced a sixth preset distance from the radial iron core to form a second axial working clearance.

[0015] The axial length of the fourth annular portion is greater than the axial length of the third annular portion, and the end of the fourth annular portion opposite to the radial iron core is located on the radial outer side of the bearing rotor, such that the end of the fourth annular portion opposite to the radial iron core is radially opposite to a portion of the structure of the bearing rotor.

[0016] In some embodiments, the first axial winding is energized in the opposite direction to the second axial winding.

[0017] In some embodiments, the radial core includes a radial stator yoke and a radial stator pole. The radial stator yoke has an annular structure. The radial outer end of the radial stator pole is connected to the radial stator yoke, and the radial inner end protrudes toward the bearing rotor and has a radial working gap with the bearing rotor. The radial winding is wound on each radial stator pole.

[0018] Furthermore, within the radial section, the radial stator includes a first quadrant portion located in the upper right, a second quadrant portion located in the upper left, a third quadrant portion located in the lower left, and a fourth quadrant portion located in the lower right. The first quadrant portion, the second quadrant portion, the third quadrant portion, and the fourth quadrant portion are connected sequentially in a counterclockwise direction. The first quadrant portion and the third quadrant portion form a diagonal, and the second quadrant portion and the fourth quadrant portion form a diagonal. The magnetic circuit formed by the radial stator pole and the yoke portion in the second quadrant portion is connected to the magnetic circuit formed by the radial stator pole and the yoke portion in the fourth quadrant portion, forming a left radial control magnetic circuit. The magnetic circuit formed by the radial stator pole and the yoke portion in the first quadrant portion is connected to the magnetic circuit formed by the radial stator pole and the yoke portion in the third quadrant portion, forming a right radial control magnetic circuit.

[0019] In some embodiments, the number of radial stator poles is 4n, where n is a natural number.

[0020] In some embodiments, the radial stator poles include a first pole and a second pole, wherein the circumferential width of the first pole is greater than the circumferential width of the second pole in the radial section, and at least one first pole and at least one second pole are distributed in each quadrant.

[0021] In some embodiments, the bias magnetic flux provided by the axial magnetic bearing to the radial magnetic bearing forms an axial bias magnetic circuit in the radial direction toward the center of the rotating shaft; or, the bias magnetic flux provided by the axial magnetic bearing to the radial magnetic bearing forms an axial bias magnetic circuit in the radial direction away from the center of the rotating shaft; in the two diagonally opposite quadrants, the radial magnetic flux in one quadrant is radially toward the center of the rotating shaft, and the radial magnetic flux in the other quadrant is radially away from the center of the rotating shaft.

[0022] In some embodiments, when the first axial stator includes a first axial core and a first axial winding, the first axial core includes a first body portion, a first annular portion, and a second annular portion, and the second axial stator includes a second axial core and a second axial winding, the second axial core includes a second body portion, a third annular portion, and a fourth annular portion:

[0023] The radial winding is located radially outside both the second annular portion and the fourth annular portion, and both the second annular portion and the fourth annular portion are opposite to the radial stator pole.

[0024] The present invention also provides an electric motor comprising the magnetically levitated active three-degree-of-freedom bearing as described in any of the preceding claims.

[0025] The present invention also provides a compressor comprising the magnetically levitated active three-degree-of-freedom bearing as described in any of the preceding claims.

[0026] The magnetically levitated active three-degree-of-freedom bearing, motor, and compressor provided by this invention have the following beneficial effects:

[0027] 1. This invention, through the effective arrangement of axial and radial magnetic bearings, allows the radial stator to be located on the outer periphery of the bearing rotor and to apply radial electromagnetic force to the bearing rotor. At least a portion of the structure of the first axial stator is located at one axial end of the bearing rotor, and at least a portion of the structure of the second axial stator is located at the other axial end of the bearing rotor. The first and second axial stators can apply axial electromagnetic force to the bearing rotor, thereby allowing the radial stator to apply radial electromagnetic force to adjust the radial offset of the bearing rotor shaft. Simultaneously, the bearing rotor can also be adjusted axially by applying axial electromagnetic force from the first and second axial stators, ultimately achieving radial and axial support for the shaft. Furthermore, at least a portion of the first and second axial stators are located radially outside the bearing rotor, ensuring that the bias magnetic flux of the radial magnetic bearing is provided by the axial magnetic bearing. This eliminates the need for existing active three-degree-of-freedom magnetic levitation bearings, which require structures such as bias stators to provide a bias magnetic path for the radial bearing. In terms of the proposed solution, the present invention, through the aforementioned structural arrangement, enables the first and second axial stators to effectively provide a bias magnetic circuit for the radial stator, eliminating the need for existing structures such as bias stators. This results in a more compact and simpler structure, reduced manufacturing difficulty, smaller size, and easier assembly. The present invention effectively combines the radial and axial magnetic bearings into a single integrated axial and radial magnetic bearing structure. Compared to the existing technology where separate axial and radial magnetic bearings require separate thrust bearings for the axial magnetic bearing to provide axial force to the shaft, and separate radial magnetic bearing rotors for the radial magnetic bearing, the present invention effectively eliminates the thrust bearing structure, resulting in a significant reduction and shortening of the rotor's axial dimension. The integration of the radial and axial bearings eliminates the need for a thrust disk, leading to a compact structure, reduced bearing size, shorter rotor length, increased rotor critical speed, and improved stability and applicability of the magnetic levitation system. Furthermore, by providing a bias magnetic circuit for the radial stator through the axial stator, the present invention effectively eliminates the need for permanent magnets compared to hybrid magnetic levitation bearings, resulting in lower cost, easier assembly, higher load-bearing capacity, and the ability to operate at high power.

[0028] 2. This invention also effectively reduces axial magnetic leakage in the radial magnetic circuit by arranging the radial windings on the radially outer side of the first and second axial cores, and by ensuring that the second and fourth annular portions are opposite to the radial stator poles. This is in contrast to the existing scheme where the upper magnetic pole of the axial stator is located next to the radial stator yoke (i.e., the existing upper magnetic pole of the axial stator is located on the axial side of the radial stator yoke). This effectively eliminates the uneven axial output force in the circumferential direction. Furthermore, the diagonally connected radial magnetic circuit configuration provides two power amplifiers. Compared to the existing four-channel power amplifier structure, this invention effectively reduces material costs and current losses. Moreover, the magnetic circuit controls a wide range of radial movement of the shaft, resulting in good control effect, high precision, and a simple control method. Attached Figure Description

[0029] Figure 1 This is a longitudinal section structural diagram (axial section, axial magnetic circuit of the three-degree-of-freedom bearing) of the magnetic levitation active three-degree-of-freedom bearing of the present invention;

[0030] Figure 2 yes Figure 1 Diagram showing the assembly structure of the axial stator, radial stator, and bearing rotor in the upper and middle sections;

[0031] Figure 3 This is a cross-sectional structural diagram (radial section, radial magnetic circuit of the three-degree-of-freedom bearing) of the present invention, showing the active three-degree-of-freedom bearing.

[0032] The reference numerals in the attached figures are as follows:

[0033] 100, Axial magnetic bearing; 300, First axial stator; 1, First axial core; 1a, First main body; 1b, First annular portion; 1c, Second annular portion; 1d, First receiving groove; 3, First axial winding; 400, Second axial stator; 2, Second axial core; 2a, Second main body; 2b, Third annular portion; 2c, Fourth annular portion; 2d, Second receiving groove; 4, Second axial winding; 200, Radial magnetic bearing; 500, Radial stator; 5, Radial winding; 6, Radial core; 61, Third axial end; 62. Fourth axial end; 7. Bearing rotor; 71. First axial end; 72. Second axial end; 8. Shaft; 9. Left axial upward magnetic pole; 10. Right axial upward magnetic pole; 11. Radial stator yoke; 12. Radial stator pole; 13. Left axial downward magnetic pole; 14. Right axial downward magnetic pole; 15. Radial working clearance; 16. First axial working clearance; 001. Axial bias magnetic circuit; 002. Left radial control magnetic circuit; 003. Right radial control magnetic circuit; 17. First pole; 18. Second pole; 19. Second axial working clearance. Detailed Implementation

[0034] like Figure 1-3As shown, the present invention provides a magnetically levitated active three-degree-of-freedom bearing, which includes:

[0035] An axial magnetic bearing 100, a radial magnetic bearing 200, and a bearing rotor 7 are provided. Both the axial magnetic bearing 100 and the radial magnetic bearing 200 are sleeved on the outer periphery of a rotating shaft 8. The axial magnetic bearing 100 includes a first axial stator 300 and a second axial stator 400. The radial magnetic bearing 200 includes a radial stator 500. The bearing rotor 7 is sleeved on the outer periphery of the rotating shaft 8 and can rotate with the rotating shaft 8. The radial stator 500 is located on the outer periphery of the bearing rotor 7 and can apply radial electromagnetic force to the bearing rotor 7. At least a portion of the structure of the first axial stator 300 is located at one axial end of the bearing rotor 7 along the axial direction of the rotating shaft 8, and at least a portion of the structure of the second axial stator 400 is located at one axial end of the bearing rotor 7. The substructure is located at the other axial end of the bearing rotor 7. The first axial stator 300 and the second axial stator 400 can apply axial electromagnetic force to the bearing rotor 7. The radial stator 500 includes a radial core 6 and a radial winding 5. The radial core 6 is an annular structure and is sleeved on the radial outer side of the bearing rotor 7 and located on the radial inner side of the radial winding 5. At least a portion of the structure of the first axial stator 300 is located on the radial outer side of the bearing rotor 7 and on the radial inner side of the radial winding 5. At least a portion of the structure of the second axial stator 400 is located on the radial outer side of the bearing rotor 7, such that the bias magnetic flux of the radial magnetic bearing 200 is provided by the axial magnetic bearing 100.

[0036] This invention, through the effective arrangement of axial and radial magnetic bearings, allows the radial stator to be located on the outer periphery of the bearing rotor and to apply radial electromagnetic force to the bearing rotor. At least a portion of the first axial stator is located at one axial end of the bearing rotor, and at least a portion of the second axial stator is located at the other axial end of the bearing rotor. The first and second axial stators can apply axial electromagnetic force to the bearing rotor, thereby allowing the radial stator to apply radial electromagnetic force to adjust the radial offset of the bearing rotor shaft. Simultaneously, the bearing rotor can also be adjusted for axial offset by applying axial electromagnetic force from the first and second axial stators, ultimately achieving radial and axial support for the shaft. Furthermore, at least a portion of the first and second axial stators are located radially outside the bearing rotor, ensuring that the bias magnetic flux of the radial magnetic bearing is provided by the axial magnetic bearing. This eliminates the need for existing active three-degree-of-freedom magnetic levitation bearings, which require structures such as bias stators to provide a bias magnetic path for the radial bearing. In terms of the solution, the present invention, through the above-mentioned structural arrangement, enables the first and second axial stators to effectively provide bias magnetic circuits for the radial stator, eliminating the need for original structures such as bias stators. This results in a more compact and simpler structure, reduced manufacturing difficulty, smaller size, and easier assembly. The present invention effectively combines the radial and axial magnetic bearings into an integrated axial and radial magnetic bearing structure. Compared to the existing technology where separate axial and radial magnetic bearings require separate thrust bearings for the axial magnetic bearing to provide axial force to the shaft, and separate radial magnetic bearing rotors for the radial magnetic bearing, the present invention effectively eliminates the thrust bearing structure, effectively reducing and shortening the rotor's axial dimension. Integrating the radial and axial bearings eliminates the need for a thrust disk, resulting in a compact structure, reduced bearing size, shorter rotor length, increased rotor critical speed, and improved stability and applicability of the magnetic levitation system. Furthermore, by providing bias magnetic circuits for the radial stator through the axial stator, the present invention effectively eliminates the need for permanent magnets compared to hybrid magnetic levitation bearings, resulting in lower cost, easier assembly, higher load-bearing capacity, and the ability to operate at high power.

[0037] The active three-degree-of-freedom magnetic bearing proposed in this invention adopts a single-coil axial winding, which is installed in the left and right axial stators and connected to the radial stator poles to provide an axial magnetic circuit and control the axial movement of the bearing rotor. The radial bearing has 4n magnetic poles (n is 1, 2, 3, 4...). The upper magnetic pole of the radial stator is the N pole, and the lower magnetic pole of the radial stator is the S pole (or the upper end is the S pole and the lower end is the N pole). The bias magnetic circuit provided by the axial magnetic circuit in the radial direction enhances or weakens the radial air gap magnetic field, controls the radial movement of the shaft, and simultaneously realizes the movement of the shaft in three degrees of freedom: radial and axial. This effectively reduces the volume of the bearing stator, shortens the shaft length, and improves the rotor's running stability.

[0038] This invention effectively eliminates the thrust plate, replacing it with a bearing rotor, thus integrating the radial and axial bearings. Compared to conventional active magnetic bearings, it eliminates the need for a thrust plate, resulting in a compact structure and simple manufacturing process. Compared to typical hybrid three-degree-of-freedom magnetic bearings, it lacks permanent magnets, relying instead on electromagnetic force to provide the bias and control magnetic fields. This results in high load-bearing capacity, high stiffness, and flexible control. This three-degree-of-freedom magnetic bearing can operate at high power and has a high critical speed, improving the stability and applicability of magnetic levitation systems.

[0039] Technical problems to be solved:

[0040] 1. This invention integrates radial and axial bearings, eliminating the need for a thrust disc, resulting in a compact structure, reduced bearing size, shorter rotor length, increased rotor critical speed, and improved stability and applicability of the magnetic levitation system.

[0041] 2. Compared with the method of axial magnetic poles located next to radial stator yoke, this invention reduces magnetic leakage in the radial magnetic circuit in the axial direction and eliminates uneven circumferential axial output force.

[0042] Beneficial effects:

[0043] 1. The radial and axial bearing stator of the present invention has a simple processing technology and convenient control of the radial and axial magnetic circuits.

[0044] 2. This invention features high radial and axial integration, eliminates the thrust disk, reduces costs, has a compact structure, simple manufacturing process, high critical speed, and stable performance; it also eliminates permanent magnets, resulting in low cost, convenient assembly, high load-bearing capacity, and the ability to operate at high power.

[0045] In some embodiments, the axial length of the radial core 6 is less than the axial length of the bearing rotor 7 in the axial direction. This is a preferred structural form of the radial stator of the present invention, which includes a radial core and radial windings. Furthermore, by making the axial length of the radial core less than the axial length of the bearing rotor, the present invention allows at least a portion of the structure of the first axial stator to extend into the space where the radial core is shorter than the bearing rotor. This allows the magnetic circuit of the first axial stator to enter the radial stator and then the bearing rotor, effectively providing a bias magnetic circuit for the radial stator without the need for additional bias stators, permanent magnets, or other structures. Similarly, the present invention, through the above structure, allows at least a portion of the structure of the second axial stator to extend into the space where the radial core is shorter than the bearing rotor. This allows the magnetic circuit of the second axial stator to enter the radial stator and then the bearing rotor, effectively providing a bias magnetic circuit for the radial stator without the need for additional bias stators, permanent magnets, or other structures. The structure is more compact, the volume is reduced, and an integrated active three-degree-of-freedom magnetic levitation bearing is formed.

[0046] In some embodiments, the first axial end 71 of the bearing rotor 7 opposite to the first axial stator 300 protrudes by a first predetermined distance from the third axial end 61 of the radial core 6 opposite to the first axial stator 300, such that the third axial end 61 of the radial core 6 is retracted relative to the first axial end 71 to form a first space, and at least a portion of the structure of the first axial stator 300 extends into the first space to be radially opposite to a portion of the structure of the bearing rotor 7.

[0047] The second axial end 72 of the bearing rotor 7, which is opposite to the second axial stator 400, protrudes by a second predetermined distance from the fourth axial end 62 of the radial core 6, which is opposite to the second axial stator 400. This causes the fourth axial end 62 of the radial core 6 to retract relative to the second axial end 72 to form a second space. At least a portion of the structure of the second axial stator 400 extends into the second space so as to be radially opposite to a portion of the structure of the bearing rotor 7.

[0048] This is a preferred fit structure between the radial core, the first axial stator, and the second axial stator of the present invention. Specifically, the first space formed by the third axial end of the radial core retracting inward by a first predetermined distance relative to the first axial end of the bearing rotor can accommodate at least a portion of the structure of the first axial stator extending into the first space. This allows the magnetic flux generated by the first axial stator to enter the radial stator and then into the bearing rotor, providing a bias magnetic circuit for the radial stator. This eliminates the need for additional bias stators, permanent magnets, or other structures, resulting in a more compact structure and reduced volume. Similarly, the second space formed by the fourth axial end of the radial core retracting inward by a second predetermined distance relative to the second axial end of the bearing rotor can accommodate at least a portion of the structure of the second axial stator extending into the second space. This allows the magnetic flux generated by the second axial stator to enter the radial stator and then into the bearing rotor, providing a bias magnetic circuit for the radial stator. This also eliminates the need for additional bias stators, permanent magnets, or other structures, resulting in a more compact structure and reduced volume.

[0049] In some embodiments, the first axial stator 300 includes a first axial core 1 and a first axial winding 3. The first axial core 1 has a ring structure and includes a first main body portion 1a and a first ring portion 1b (i.e., Figure 1 The left lower magnetic pole 13) and the second annular part 1c (i.e. Figure 1The first main body 1a is a disk structure with a first central hole, through which the rotating shaft 8 passes. The second annular part 1c is located radially outside the first annular part 1b. One end of the first annular part 1b is connected to the first main body 1a (preferably radially inner end) and the other end extends toward the bearing rotor 7 to be opposite to the bearing rotor 7. One end of the second annular part 1c is connected to the first main body 1a (preferably radially outer end) and the other end extends toward the radial iron core 6 to be opposite to the radial iron core 6 and extends into the first space to form a first receiving groove 1d between the radially outer side of the first annular part 1b and the radially inner side of the second annular part 1c. The first axial winding 3 is disposed in the first receiving groove 1d and wound around the outer periphery of the first annular part 1b.

[0050] This is a preferred structural form of the first axial stator of the present invention. The first annular portion and the second annular portion can form a first receiving groove to accommodate the first axial winding. The first annular portion is opposite to the bearing rotor to accommodate the magnetic circuit. The second annular portion is opposite to the radial iron core, and the end of the second annular portion opposite to the radial iron core extends into the first space. This can effectively improve the radial iron core and the second annular portion, so that the second annular portion, the radial iron core, the bearing rotor, the first annular portion and the first main body form a closed magnetic path. This structure can enable the first axial stator to provide radial bias magnetic flux to the radial stator, so that the first axial stator and the radial stator are integrated into a single structure, effectively eliminating the need for thrust disk, permanent magnet, bias stator and other structures, resulting in a compact structure and a significant reduction in volume.

[0051] In some embodiments, the first annular portion 1b extends along the axial direction of the rotating shaft 8 and is spaced apart from the bearing rotor 7 by a third preset distance, forming a first axial working gap 16; the second annular portion 1c also extends along the axial direction of the rotating shaft 8 and is spaced apart from the radial iron core 6 by a fourth preset distance, forming a second axial working gap 19.

[0052] The axial length of the second annular portion 1c is greater than the axial length of the first annular portion 1b, and the end of the second annular portion 1c opposite to the radial iron core 6 is located on the radial outer side of the bearing rotor 7, such that the end of the second annular portion 1c opposite to the radial iron core 6 is radially opposite to a portion of the structure of the bearing rotor 7.

[0053] This is a preferred structural form of the first and second annular portions of the present invention. The first annular portion extends axially and forms a first axial working gap with the bearing rotor, allowing magnetic flux to pass between the first annular portion and the bearing rotor. The first annular portion does not rotate with the bearing rotor. The second annular portion is spaced apart from the radial iron core by a second axial working gap, allowing magnetic flux to pass between the second annular portion and the radial iron core. The second annular portion does not generate friction or magnetic leakage with the radial stator. The axial length of the second annular portion is greater than that of the first annular portion, allowing the end of the second annular portion opposite to the radial iron core to extend into the first space. It is also opposite to a portion of the bearing rotor in the radial direction, enabling the magnetic circuit in the first axial stator to be transferred to the radial iron core and the bearing rotor. This results in a more compact integrated bearing stator and radial stator structure, eliminating the need for thrust plates, offset stators, permanent magnets, and other structures, thus reducing the volume.

[0054] In some embodiments, the second axial stator 400 includes a second axial core 2 and a second axial winding 4. The second axial core 2 is an annular structure, comprising a second main body 2a, a third annular portion 2b, and a fourth annular portion 2c. The second main body 2a is a disc structure with a second central hole, through which the rotating shaft 8 passes. One end of the third annular portion 2b is connected to the second main body 2a (preferably the radially inner end), and the other end extends toward the bearing rotor 7 to be opposite to the bearing rotor 7. One end of the fourth annular portion 2c is connected to the second main body 2a (preferably the radially outer end), and the other end extends toward the radial core 6 to be opposite to the radial core 6. The fourth annular portion 2c is located radially outside the third annular portion 2b to form a second receiving groove 2d between the radially outer side of the third annular portion 2b and the radially inner side of the fourth annular portion 2c. The second axial winding 4 is disposed in the second receiving groove 2d and wound around the outer periphery of the third annular portion 2b.

[0055] This is a preferred structural form of the second axial stator of the present invention. The third and fourth annular portions can form a second receiving groove to accommodate the second axial winding. The third annular portion is opposite to the bearing rotor to accommodate the magnetic circuit. The fourth annular portion is opposite to the radial iron core, and the end of the fourth annular portion opposite to the radial iron core extends into the second space. This can effectively improve the radial iron core and the fourth annular portion, so that the fourth annular portion, the radial iron core, the bearing rotor, the third annular portion and the second main body form a closed magnetic path. This structure can enable the second axial stator to provide radial bias magnetic flux to the radial stator, so that the second axial stator and the radial stator are integrated into a single structure, effectively eliminating the need for thrust disk, permanent magnet, bias stator and other structures, resulting in a compact structure and a significant reduction in volume.

[0056] In some embodiments, the third annular portion 2b extends along the axial direction of the rotating shaft 8 and is spaced a fifth preset distance from the bearing rotor 7 to form a first axial working gap 16; the fourth annular portion 2c also extends along the axial direction of the rotating shaft 8 and is spaced a sixth preset distance from the radial iron core 6 to form a second axial working gap 19.

[0057] The axial length of the fourth annular portion 2c is greater than the axial length of the third annular portion 2b, and the end of the fourth annular portion 2c opposite to the radial iron core 6 is located on the radial outer side of the bearing rotor 7, such that the end of the fourth annular portion 2c opposite to the radial iron core 6 is radially opposite to a portion of the structure of the bearing rotor 7.

[0058] This is a preferred structural form of the third and fourth annular portions of the present invention. The third annular portion extends axially and forms a first axial working gap with the bearing rotor, allowing magnetic flux to pass between the third annular portion and the bearing rotor. The third annular portion does not rotate with the bearing rotor. The fourth annular portion is separated from the radial iron core by a second axial working gap, allowing magnetic flux to pass between the fourth annular portion and the radial iron core. The fourth annular portion does not generate friction or magnetic leakage with the radial stator. The axial length of the fourth annular portion is greater than that of the third annular portion, allowing the end of the fourth annular portion opposite to the radial iron core to extend into the second space. It is also opposite to a portion of the bearing rotor structure in the radial direction, enabling the magnetic circuit in the second axial stator to be transmitted to the radial iron core and the bearing rotor. This results in a more compact integrated bearing stator and radial stator structure, eliminating the need for thrust plates, offset stators, permanent magnets, and other structures, thus reducing the volume.

[0059] In some embodiments, the first axial winding 3 and the second axial winding 4 are energized in opposite directions. The opposite energizing directions of the two axial windings in this invention ensure that the bias magnetic flux generated by the two axial stators on the radial stator is directed radially inward, providing a larger bias magnetic path for the radial core. This reduces the radial magnetic flux of the radial winding, decreases its power, and improves the utilization rate of the axial magnetic bearing. Furthermore, the radial winding, wound along the axial direction, generates a radial magnetic flux that can point either radially inward or radially outward, thus providing a control magnetic path for the radial output force of the magnetic levitation bearing.

[0060] The active three-degree-of-freedom magnetic bearing structure of the present invention is as follows: Figure 1As shown, compared with the traditional active magnetic bearing structure, the thrust disk is removed and replaced by the bearing rotor. The axial stator is located at both ends of the radial stator. The radial bearing and the axial bearing are integrated. The structure is mainly composed of the left axial stator (including the first axial iron core 1 and the first axial winding 3), the right axial stator (including the second axial iron core 2 and the second axial winding 4), the radial winding 5, the radial stator (including the radial iron core 6 and the radial winding 5), the bearing rotor 7, the shaft (8), and other parts.

[0061] Figure 1 The diagram shows the axial magnetic circuit of an active three-degree-of-freedom axial bearing. The axial stator structure is shown in the figure. The upper magnetic pole of the axial stator is located at the lower end of the radial winding 5 and is connected to the radial stator pole 12. The lower axial magnetic pole is located at both ends of the bearing rotor 7. The axial bias magnetic circuit 001 generated by the axial winding includes a left axial magnetic circuit and a right axial magnetic circuit, used to control the axial movement of the bearing rotor. The left axial magnetic circuit returns to the left axial stator (i.e., the first main body) via the left axial upper magnetic pole 9 - radial stator pole 12 - radial working gap 15 - bearing rotor 7 - first axial working gap 16 - left axial lower magnetic pole 13. When part 1a) is closed, the right axial magnetic path returns to the right axial stator (i.e., the second main body part 2a) via the right axial upward magnetic pole 10, radial stator pole 12, radial working gap 15, bearing rotor 7, first axial working gap 16, and right axial downward magnetic pole 14. When the bearing rotor needs to be controlled to move to the left, the left axial winding current is increased, and the bearing rotor experiences a greater force to the left. Conversely, when the bearing rotor needs to be controlled to move to the right, the right axial winding current is increased, and the bearing rotor experiences a greater force to the right. Thus, the axial movement of the bearing rotor is controlled by controlling the magnitude of the left and right axial winding currents.

[0062] In some embodiments, the radial core 6 includes a radial stator yoke 11 and a radial stator pole 12. The radial stator yoke 11 has an annular structure. The radial outer end of the radial stator pole is connected to the radial stator yoke 11, and the radial inner end protrudes toward the bearing rotor 7 and has a radial working gap 15 between it and the bearing rotor 7. The radial winding 5 is wound on each radial stator pole.

[0063] Furthermore, within the radial section, the radial stator 500 includes a first quadrant portion located in the upper right, a second quadrant portion located in the upper left, a third quadrant portion located in the lower left, and a fourth quadrant portion located in the lower right. The first quadrant portion, the second quadrant portion, the third quadrant portion, and the fourth quadrant portion are connected sequentially in a counterclockwise direction. The first quadrant portion and the third quadrant portion form a diagonal, and the second quadrant portion and the fourth quadrant portion form a diagonal. The magnetic circuit formed by the radial stator pole and the yoke portion in the second quadrant portion is connected to the magnetic circuit formed by the radial stator pole and the yoke portion in the fourth quadrant portion, forming a left radial control magnetic circuit 002. The magnetic circuit formed by the radial stator pole and the yoke portion in the first quadrant portion is connected to the magnetic circuit formed by the radial stator pole and the yoke portion in the third quadrant portion, forming a right radial control magnetic circuit 003.

[0064] The present invention also provides two power amplifiers by setting up a radial magnetic circuit that is diagonally connected. Compared with the existing structure that uses four power amplifiers, the present invention can effectively reduce material costs and current loss. Furthermore, the magnetic circuit controls the radial movement of the rotating shaft to a wide range, resulting in good control effect, high precision, and a simple control method.

[0065] Figure 3 The diagram shows the radial magnetic circuit of the active three-degree-of-freedom radial bearing of the present invention. The radial stator structure is shown in the figure, with 4n magnetic poles (n being 1, 2, 3, 4...). The upper magnetic pole of the radial stator is the N pole, and the lower magnetic pole of the radial stator is the S pole (or the upper end is the S pole and the lower end is the N pole). The radial magnetic circuit is as follows. Figure 3 As shown. The upper left coil and the lower right coil of the radial stator are connected in series to generate the left radial control magnetic circuit 002. The upper right coil and the lower left coil of the radial stator are connected in series to generate the right radial control magnetic circuit 003. If the bearing rotor is moved to the upper left, a positive current is applied to the coil. The left radial control magnetic circuit 002 returns to the upper left radial stator pole (first pole 17) through the upper left radial stator pole (first pole 17) - radial working gap 15 - bearing rotor 7 - radial working gap 15 - lower right radial stator pole (first pole 17) - radial stator yoke 11 to close. The axial bias magnetic circuit 001 provided in the axial direction is as follows. Figure 3As shown by the dashed lines, all pointing towards the center (or the circumference), the magnetic field of the upper left magnetic pole of the radial stator is strengthened, while the magnetic field of the lower right magnetic pole is weakened, causing the bearing rotor to experience a force to the upper left. Similarly, if the bearing rotor is moved to the upper right, the magnetic field of the upper right magnetic pole of the radial stator is strengthened, while the magnetic field of the lower left magnetic pole is weakened. The radial movement of the bearing rotor is controlled by adjusting the magnitude and sign of the radial current, achieving stable radial levitation. The above magnetic circuit controls a wide range of radial movement of the shaft, and the control method is simple. This three-degree-of-freedom magnetic bearing structure integrates the radial and axial bearings, eliminating the thrust disk, resulting in a compact structure and simple manufacturing process. It effectively reduces the bearing volume, increases the rotor's critical speed, and improves system operational stability while maintaining the same output force.

[0066] In some embodiments, the radial stator pole 12 includes a first pole 17 and a second pole 18. In the radial cross-section, the circumferential width of the first pole 17 is greater than the circumferential width of the second pole 18, and at least one first pole 17 and at least one second pole 18 are distributed in each quadrant. The number of radial stator poles is 4n, where n is a natural number. This is a preferred structural form of the radial stator poles of the present invention, which includes two poles with different circumferential widths, enabling the formation of different magnetic fluxes that can be controlled as needed.

[0067] In some embodiments, each quadrant contains one first pole post 17 and two second pole posts 18. In the circumferential direction, one second pole post 18 is positioned on one circumferential side of the first pole post 17, and another second pole post 18 is positioned on the other circumferential side, such that the first pole post 17 is located between the two second pole posts 18. This is a further preferred pole post distribution in each quadrant of the present invention, where the pole post with larger magnetic flux is located in the middle, and the two pole posts with smaller magnetic flux are located on either side. This arrangement can be tailored to the actual spatial structure, maximizing the magnetic flux, and the placement of the large pole post effectively avoids magnetic flux saturation.

[0068] In some embodiments, the bias magnetic flux provided by the axial magnetic bearing 100 to the radial magnetic bearing 200 forms an axial bias magnetic circuit 001 in the radial direction toward the center of the rotating shaft 8; or, the bias magnetic flux provided by the axial magnetic bearing 100 to the radial magnetic bearing 200 forms an axial bias magnetic circuit 001 in the radial direction away from the center of the rotating shaft 8; in the two diagonally opposite quadrants, the radial magnetic flux in one quadrant is radially toward the center of the rotating shaft 8, and the radial magnetic flux in the other quadrant is radially away from the center of the rotating shaft 8.

[0069] This invention utilizes the axial magnetic bearing to provide bias magnetic flux that is radially oriented towards the center of the shaft, thus forming a relatively constant bias magnetic circuit. Furthermore, the bias magnetic flux generated by both axial stators is either radially inward or radially outward, effectively increasing the magnetic flux and reducing the radial flux of the radial winding, thereby reducing the power of the radial winding and improving the utilization rate of the axial magnetic bearing. In the two diagonally opposite quadrants, one quadrant has a magnetic flux radially inward, and the other quadrant has a magnetic flux radially outward. The magnetic flux in the radially inward quadrant can enter the bearing rotor, and the magnetic circuit can be led out to the stator yoke through the magnetic flux in the other quadrant, thus forming a closed-loop circuit. This control method greatly enhances control capability. For example, if the shaft needs to be driven to the upper left, this invention increases the winding current in the second and fourth quadrants, simultaneously driving both the second and fourth quadrants to move to the upper left. This effectively increases the control capability and efficiency of the shaft compared to existing magnetic levitation bearings.

[0070] In some embodiments, when the first axial stator 300 includes a first axial core 1 and a first axial winding 3, the first axial core 1 includes a first main body portion 1a, a first annular portion 1b, and a second annular portion 1c, and the second axial stator 400 includes a second axial core 2 and a second axial winding 4, the second axial core 2 includes a second main body portion 2a, a third annular portion 2b, and a fourth annular portion 2c:

[0071] The radial winding 5 is located radially outside both the second annular portion 1c and the fourth annular portion 2c, and both the second annular portion 1c and the fourth annular portion 2c are opposite to the radial stator pole.

[0072] The present invention also effectively reduces the leakage flux of the radial magnetic circuit in the axial direction and effectively eliminates the uneven axial output force in the circumferential direction by setting the radial winding on the radial outside of the first axial core and the second axial core, and by having the second annular portion and the fourth annular portion opposite to the radial stator pole, compared with the existing scheme where the upper magnetic pole of the axial stator is located next to the radial stator yoke (i.e., the existing scheme where the upper magnetic pole of the axial stator is located on the axial side of the radial stator yoke).

[0073] The present invention also provides an electric motor comprising the magnetically levitated active three-degree-of-freedom bearing as described in any of the preceding claims.

[0074] The present invention also provides a compressor comprising the magnetically levitated active three-degree-of-freedom bearing as described in any of the preceding claims.

[0075] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A magnetically levitated active three-degree-of-freedom bearing, characterized in that: include: An axial magnetic bearing (100), a radial magnetic bearing (200), and a bearing rotor (7) are provided. Both the axial magnetic bearing (100) and the radial magnetic bearing (200) are sleeved on the outer periphery of a rotating shaft (8). The axial magnetic bearing (100) includes a first axial stator (300) and a second axial stator (400). The radial magnetic bearing (200) includes a radial stator (500). The bearing rotor (7) is sleeved on the outer periphery of the rotating shaft (8) and can rotate with the rotating shaft (8). The radial stator (500) is located on the outer periphery of the bearing rotor (7) and can apply radial electromagnetic force to the bearing rotor (7). At least a portion of the structure of the first axial stator (300) is located at one axial end of the bearing rotor (7) along the axial direction of the rotating shaft (8). The second axial stator (400)... At least a portion of the structure is located at the other axial end of the bearing rotor (7), and the first axial stator (300) and the second axial stator (400) can apply axial electromagnetic force to the bearing rotor (7); the radial stator (500) includes a radial core (6) and a radial winding (5), the radial core (6) is an annular structure and is sleeved on the radial outer side of the bearing rotor (7); at least a portion of the structure of the first axial stator (300) is located on the radial outer side of the bearing rotor (7) and on the radial inner side of the radial winding (5), and at least a portion of the structure of the second axial stator (400) is located on the radial outer side of the bearing rotor (7) and on the radial inner side of the radial winding (5), such that the bias magnetic flux of the radial magnetic bearing (200) is provided by the axial magnetic bearing (100); In the axial direction, the axial length of the radial core (6) is less than the axial length of the bearing rotor (7). The first axial end (71) of the bearing rotor (7) opposite to the first axial stator (300) protrudes by a first preset distance than the third axial end (61) of the radial core (6) opposite to the first axial stator (300), so that the third axial end (61) of the radial core (6) is retracted relative to the first axial end (71) to form a first space. At least a portion of the structure of the first axial stator (300) extends into the first space to be radially opposite to a portion of the structure of the bearing rotor (7).

2. The magnetically levitated active three-degree-of-freedom bearing according to claim 1, characterized in that: The second axial end (72) of the bearing rotor (7) opposite to the second axial stator (400) protrudes by a second predetermined distance than the fourth axial end (62) of the radial core (6) opposite to the second axial stator (400), so that the fourth axial end (62) of the radial core (6) retracts relative to the second axial end (72) to form a second space, and at least a portion of the structure of the second axial stator (400) extends into the second space to be radially opposite to a portion of the structure of the bearing rotor (7).

3. The magnetically levitated active three-degree-of-freedom bearing according to claim 2, characterized in that: The first axial stator (300) includes a first axial core (1) and a first axial winding (3). The first axial core (1) is an annular structure, comprising a first main body (1a), a first annular portion (1b), and a second annular portion (1c). The first main body (1a) is a disk structure with a first central hole through which the rotating shaft (8) passes. The second annular portion (1c) is located radially outside the first annular portion (1b), and one end of the first annular portion (1b) is adjacent to the first main body (1a). The other end extends toward the bearing rotor (7) to be opposite to the bearing rotor (7), one end of the second annular portion (1c) is connected to the first main body portion (1a) and the other end extends toward the radial iron core (6) to be opposite to the radial iron core (6) and extends into the first space to form a first receiving groove (1d) between the radial outer side of the first annular portion (1b) and the radial inner side of the second annular portion (1c), and the first axial winding (3) is disposed in the first receiving groove (1d) and wound around the outer periphery of the first annular portion (1b).

4. The magnetically levitated active three-degree-of-freedom bearing according to claim 3, characterized in that: The first annular portion (1b) extends along the axial direction of the rotating shaft (8) and is spaced at a third preset distance from the bearing rotor (7) to form a first axial working gap (16); the second annular portion (1c) also extends along the axial direction of the rotating shaft (8) and is spaced at a fourth preset distance from the radial iron core (6) to form a second axial working gap (19). The axial length of the second annular portion (1c) is greater than the axial length of the first annular portion (1b), and the end of the second annular portion (1c) opposite to the radial iron core (6) is located on the radial outer side of the bearing rotor (7), such that the end of the second annular portion (1c) opposite to the radial iron core (6) is radially opposite to a portion of the structure of the bearing rotor (7).

5. The magnetically levitated active three-degree-of-freedom bearing according to claim 3, characterized in that: The second axial stator (400) includes a second axial core (2) and a second axial winding (4). The second axial core (2) is an annular structure, comprising a second main body (2a), a third annular part (2b), and a fourth annular part (2c). The second main body (2a) is a disk structure with a second central hole through which the rotating shaft (8) passes. One end of the third annular part (2b) is connected to the second main body (2a), and the other end extends toward the bearing rotor (7) to the bearing. With the rotor (7) facing each other, one end of the fourth annular portion (2c) is connected to the second main body portion (2a) and the other end extends toward the radial core (6) to face the radial core (6), and the fourth annular portion (2c) is located on the radial outer side of the third annular portion (2b) to form a second receiving groove (2d) between the radial outer side of the third annular portion (2b) and the radial inner side of the fourth annular portion (2c), and the second axial winding (4) is disposed in the second receiving groove (2d) and wound around the outer periphery of the third annular portion (2b).

6. The magnetically levitated active three-degree-of-freedom bearing according to claim 5, characterized in that: The third annular portion (2b) extends along the axial direction of the rotating shaft (8) and is spaced a fifth preset distance from the bearing rotor (7) to form a first axial working gap (16); the fourth annular portion (2c) also extends along the axial direction of the rotating shaft (8) and is spaced a sixth preset distance from the radial iron core (6) to form a second axial working gap (19). The axial length of the fourth annular portion (2c) is greater than the axial length of the third annular portion (2b), and the end of the fourth annular portion (2c) opposite to the radial core (6) is located on the radial outer side of the bearing rotor (7), such that the end of the fourth annular portion (2c) opposite to the radial core (6) is radially opposite to a portion of the structure of the bearing rotor (7).

7. The magnetically levitated active three-degree-of-freedom bearing according to claim 5, characterized in that: The first axial winding (3) is energized in the opposite direction to the second axial winding (4).

8. The magnetically levitated active three-degree-of-freedom bearing according to any one of claims 1-7, characterized in that: The radial core (6) includes a radial stator yoke (11) and a radial stator pole (12). The radial stator yoke (11) is a ring structure. The radial outer end of the radial stator pole is connected to the radial stator yoke (11), and the radial inner end protrudes toward the bearing rotor (7) and has a radial working gap (15) between it and the bearing rotor (7). The radial winding (5) is wound on each radial stator pole. Furthermore, within the radial section, the radial stator (500) includes a first quadrant portion located in the upper right, a second quadrant portion located in the upper left, a third quadrant portion located in the lower left, and a fourth quadrant portion located in the lower right. The first quadrant portion, the second quadrant portion, the third quadrant portion, and the fourth quadrant portion are connected sequentially in a counterclockwise direction. The first quadrant portion and the third quadrant portion form a diagonal, and the second quadrant portion and the fourth quadrant portion form a diagonal. The magnetic circuit formed by the radial stator pole and the yoke portion in the second quadrant portion is connected to the magnetic circuit formed by the radial stator pole and the yoke portion in the fourth quadrant portion, forming a left radial control magnetic circuit (002). The magnetic circuit formed by the radial stator pole and the yoke portion in the first quadrant portion is connected to the magnetic circuit formed by the radial stator pole and the yoke portion in the third quadrant portion, forming a right radial control magnetic circuit (003).

9. The magnetically levitated active three-degree-of-freedom bearing according to claim 8, characterized in that: The number of radial stator poles is 4n, where n is a natural number.

10. The magnetically levitated active three-degree-of-freedom bearing according to claim 9, characterized in that: The radial stator pole (12) includes a first pole (17) and a second pole (18). In the radial section, the circumferential width of the first pole (17) is greater than the circumferential width of the second pole (18), and at least one first pole (17) and at least one second pole (18) are distributed in each quadrant.

11. The magnetically levitated active three-degree-of-freedom bearing according to claim 8, characterized in that: The axial magnetic bearing (100) provides bias magnetic flux to the radial magnetic bearing (200) in a radial direction toward the center of the rotating shaft (8) to form an axial bias magnetic circuit (001); or, the axial magnetic bearing (100) provides bias magnetic flux to the radial magnetic bearing (200) in a radial direction toward the center of the rotating shaft (8) to form an axial bias magnetic circuit (001); in the two diagonally opposite quadrants, the radial magnetic flux in one quadrant is radially toward the center of the rotating shaft (8), and the radial magnetic flux in the other quadrant is radially away from the center of the rotating shaft (8).

12. The magnetically levitated active three-degree-of-freedom bearing according to claim 8, characterized in that: When the first axial stator (300) includes a first axial core (1) and a first axial winding (3), the first axial core (1) includes a first main body (1a), a first annular part (1b) and a second annular part (1c), and the second axial stator (400) includes a second axial core (2) and a second axial winding (4), the second axial core (2) includes a second main body (2a), a third annular part (2b) and a fourth annular part (2c): The radial winding (5) is located radially outside both the second annular portion (1c) and the fourth annular portion (2c), and both the second annular portion (1c) and the fourth annular portion (2c) are opposite to the radial stator pole.

13. An electric motor, characterized in that: Includes the magnetically levitated active three-degree-of-freedom bearing as described in any one of claims 1-12.

14. A compressor, characterized in that: Includes the magnetically levitated active three-degree-of-freedom bearing as described in any one of claims 1-12.

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