A magnetic levitation active bearing, a motor and a compressor

Abstract

The present invention provides a magnetic levitation active bearing, a motor and a compressor. Among them, a magnetic levitation active bearing includes: a first axial stator, a second axial stator, a radial stator, a bearing rotor and a rotating shaft. The rotating shaft is sleeved inside the bearing rotor. The first axial stator and the second axial stator are located on the outer periphery of the rotating shaft. The first axial stator is located at one end of the bearing rotor, and the second axial stator is located at the other end of the bearing rotor. The radial stator is located on the outer periphery of the bearing rotor. The radial stator includes a stator yoke. Along the radial direction of the bearing rotor, the stator yoke has 16 pole columns. The 16 pole columns are divided into 4 groups of pole columns, and the 4 groups of pole columns are symmetrically distributed on the stator yoke. The magnetic pole polarities of two adjacent pole columns in each group of pole columns are opposite. Radial coils are arranged on the 16 pole columns, which can overcome the defect of low integration degree of radial bearings and axial bearings in the prior art, so that there is no need to separately assemble a thrust disk on the rotating shaft, and the structure is more compact and the process is more simplified.

Description

Technical Field

[0001] The present invention relates to the technical field of bearings, and particularly to a magnetic levitation active bearing, a motor, and a compressor. Background Art

[0002] Magnetic levitation bearings use electromagnetic forces on the rotor to levitate the rotating shaft, and the rotating shaft and the stator remain in a non-contact state. Therefore, they have advantages such as no wear, high rotational speed, high precision, and long service life. Magnetic levitation bearings can be classified into three categories according to the working principle: active magnetic bearings, passive magnetic bearings, and hybrid magnetic bearings.

[0003] Magnetic levitation bearings are composed of radial bearings and axial bearings. The axial bearings can generate axial magnetic forces on the bearing rotor to axially levitate the rotor, and the radial bearings can generate radial magnetic forces on the bearing rotor to radially levitate the rotor. In existing magnetic levitation bearings, due to the presence of a thrust disk on the rotor, the integration degree of the radial bearings and axial bearings is not high. Summary of the Invention

[0004] Therefore, the present invention provides a magnetic levitation active bearing, a motor, and a compressor, which can overcome the defect of low integration degree of radial bearings and axial bearings in the prior art, so that there is no need to separately assemble a thrust disk on the rotating shaft, and the structure is more compact and the process is more simplified.

[0005] To solve the above problems, the present invention provides a magnetic levitation active bearing, which includes:

[0006] A first axial stator, a second axial stator, a radial stator, a bearing rotor, and a rotating shaft. The bearing rotor is sleeved on the outer periphery of the rotating shaft. The first axial stator and the second axial stator are located on the outer periphery of the rotating shaft. Along the axial direction of the bearing rotor, the first axial stator is located at one end of the bearing rotor, and the second axial stator is located at the other end of the bearing rotor. The radial stator is located on the outer periphery of the bearing rotor;

[0007] The radial stator includes a stator yoke. Along the radial direction of the bearing rotor, the stator yoke has 16 pole columns, and the 16 pole columns face the bearing rotor. In the radial cross-section of the bearing rotor, the 16 pole columns are divided into 4 groups of pole columns, and the 4 groups of pole columns are symmetrically distributed on the stator yoke. The magnetic polarities of two adjacent pole columns in each group of pole columns are opposite. Radial coils are arranged on the 16 pole columns. When the radial coils are energized, they can generate radial magnetic forces on the bearing rotor to radially levitate the bearing rotor;

[0008] The first axial stator includes a plurality of first outer pole blocks and first inner pole blocks, and the plurality of first outer pole blocks are arranged at intervals in the circumferential direction of the first axial stator; the second axial stator includes a plurality of second outer pole blocks and second inner pole blocks, and axial coils are provided between the first outer pole blocks and the first inner pole blocks and between the second outer pole blocks and the second inner pole blocks. The plurality of second outer pole blocks are arranged at intervals in the circumferential direction of the first axial stator. When the axial coils are energized, an axial magnetic force can be generated on the bearing rotor to axially suspend the bearing rotor. The plurality of first outer pole blocks and second outer pole blocks are respectively arranged corresponding to the pole columns on the stator yoke with the same polarity as them among the 16 pole columns.

[0009] In some embodiments, each group of the pole columns includes a first pole column, a second pole column, a third pole column, and a fourth pole column. The second pole column and the third pole column are located between the first pole column and the fourth pole column, and the first pole column and the fourth pole column, and the second pole column and the third pole column are symmetric. The magnetic polarities of the first pole column and the second pole column, the second pole column and the third pole column, and the third pole column and the fourth pole column are opposite.

[0010] In some embodiments, the second pole column and the third pole column have the same width, the first pole column and the fourth pole column have the same width, and the width of the third pole column is greater than the width of the fourth pole column.

[0011] In some embodiments, there are at least 6 first outer pole blocks. In one quadrant, each adjacent first pole column and second pole column, and each adjacent third pole column and fourth pole column respectively correspond to one first outer pole block;

[0012] There are at least 6 second outer pole blocks. In one quadrant, each adjacent first pole column and second pole column, and each adjacent third pole column and fourth pole column respectively correspond to one second outer pole block.

[0013] In some embodiments, there is an axial inner working gap between the first inner pole block and the end face of the bearing rotor. There is an axial outer working gap or they are in contact between the first outer pole block and the circumferential wall of the radial stator. The first outer pole block is located radially inside the radial coil.

[0014] In some embodiments, an axial magnetic circuit is formed among the first axial stator, the bearing rotor, and the radial stator. The axial magnetic circuit passes through the first outer pole block - the axial outer working gap - the pole column - the bearing rotor - the axial inner working gap - the first inner pole block and returns to the first axial stator to be closed.

[0015] In some embodiments, there is an axial inner working gap between the second inner pole block and the end face of the bearing rotor, an axial outer working gap between the second outer pole block and the circumferential wall of the radial stator, and the second outer pole block is located radially inside the radial coil.

[0016] In some embodiments, an axial magnetic circuit is formed among the second axial stator, the bearing rotor, and the radial stator. The axial magnetic circuit passes through the second outer pole block - the axial outer working gap - the pole column - the bearing rotor - the axial inner working gap - the second inner pole block and returns to the second axial stator to be closed.

[0017] The present invention also provides a motor, including the magnetic levitation active bearing described in any one of the previous items.

[0018] The present invention also provides a compressor, including the above-mentioned motor.

[0019] For the magnetic levitation active bearing, motor, and compressor provided by the present invention, the radial stator magnetic circuit, the first axial stator magnetic circuit, and the second axial stator magnetic circuit are all conducted through the bearing rotor. There is no need to design a thrust disk on the rotating shaft, the integration degree of the bearing is further improved, the overall structure and manufacturing process of the bearing are simplified, facilitating assembly, with a relatively high integration degree, a more compact structure, effectively reducing the bearing volume, shortening the rotating shaft length, increasing the rotor critical speed, and improving the operation stability of the magnetic levitation system; the 4 groups of pole columns are distributed in an SNSN or NSNS pattern, and the magnetic pole polarities of two adjacent pole columns in each group of pole columns are opposite. The electromagnetic forces generated by two adjacent pole columns are always located in the middle of the pole column, which can ensure the position of the rotating shaft in the radial direction. The multiple first outer pole blocks are arranged at intervals, and the first outer pole blocks are opposite to 16 pole columns, avoiding the magnetic leakage phenomenon of the radial magnetic circuits on adjacent radial pole columns on the outer circle of the axial stator. Description of the Drawings

[0020] Figure 1 It is a cross-sectional view of the magnetic levitation active bearing according to an embodiment of the present invention;

[0021] Figure 2 It is a front view of the magnetic levitation active bearing according to an embodiment of the present invention;

[0022] Figure 3 It is a top view of the axial stator in the magnetic levitation active bearing according to an embodiment of the present invention;

[0023] Figure 4 It is a front view of the axial stator in the magnetic levitation active bearing according to an embodiment of the present invention;

[0024] Figure 5 It is a front view of the axial stator in the magnetic levitation active bearing according to another embodiment of the present invention.

[0025] The reference numerals are indicated as follows:

[0026] 1. First axial stator; 2. Second axial stator; 3. Axial coil; 4. First pole column; 5. Radial coil; 6. Radial stator; 7. Bearing rotor; 8. Rotating shaft; 9. First outer pole block; 10. Second outer pole block; 11. Second pole column; 12. Third pole column; 13. First inner pole block; 14. Second inner pole block; 15. Radial working clearance; 16. Axial inner working clearance; 17. Fourth pole column; 18. Stator yoke; 001. Axial magnetic circuit; 002. Radial magnetic circuit. Detailed implementation manners

[0027] Refer to in combination Figures 1 to 4As shown in the figure, a magnetic levitation active bearing is provided, including: a first axial stator 1, a second axial stator 2, a radial stator 6, a bearing rotor 7, and a rotating shaft 8. The rotating shaft 8 is sleeved inside the bearing rotor 7. The first axial stator 1 and the second axial stator 2 are located on the outer periphery of the rotating shaft 8. Along the axial direction of the bearing rotor 7, the first axial stator 1 is located at one end of the bearing rotor 7, and the second axial stator 2 is located at the other end of the bearing rotor 7. The radial stator 6 is located on the outer peripheral wall of the bearing rotor 7. The radial stator 6 includes a stator yoke 18. Along the radial direction of the bearing rotor 7, the stator yoke 18 has 16 pole columns, and the 16 pole columns face the bearing rotor 7. In the radial cross-section of the bearing rotor 7, the 16 pole columns are divided into 4 groups of pole columns, and the 4 groups of pole columns are symmetrically distributed on the stator yoke 18. The magnetic polarities of two adjacent pole columns in each group of pole columns are opposite. Radial coils 5 are arranged on the 16 pole columns. When the radial coils 5 are energized, they can generate a radial magnetic force on the bearing rotor 7 to make the bearing rotor 7 radially levitate. The first axial stator 1 includes a plurality of first outer pole blocks 9 and a first inner pole block 13. The plurality of first outer pole blocks 9 are arranged at intervals along the circumferential direction of the first axial stator 1. The second axial stator 2 includes a plurality of second outer pole blocks 10 and a second inner pole block 14. Axial coils 3 are arranged between the first outer pole block 9 and the first inner pole block 13, and between the second outer pole block 10 and the second inner pole block 14. The plurality of second outer pole blocks 10 are arranged at intervals along the circumferential direction of the first axial stator 1. When the axial coils 3 are energized, they can generate an axial magnetic force on the bearing rotor 7 to make the bearing rotor 7 axially levitate. In this technical solution, the magnetic circuits of the radial stator 6, the first axial stator 1, and the second axial stator 2 are all conducted through the bearing rotor 7. There is no need to design a thrust disk on the rotating shaft 8, which further improves the integration degree of the bearing, simplifies the overall structure and the processing and manufacturing process of the bearing, is convenient for assembly, has a high integration degree, a more compact structure, effectively reduces the volume of the bearing, shortens the length of the rotating shaft, increases the critical speed of the rotor, and improves the operation stability of the magnetic levitation system. The 4 groups of pole columns are in a └┴┴┘-shaped structure, distributed in an SNSN or NSNS pattern. The magnetic polarities of two adjacent pole columns in each group of pole columns are opposite. The electromagnetic force generated by two adjacent pole columns is always located in the middle of the pole columns, which can ensure the position of the rotating shaft 8 in the radial direction. The plurality of first outer pole blocks 9 are arranged at intervals, and the first outer pole blocks 9 are opposite to the 16 pole columns, avoiding the magnetic leakage phenomenon of the radial magnetic circuits on adjacent radial pole columns on the outer circle of the axial stator. See Figure 2As shown, for the radial coils 5 of the pole columns in any group, the protruding ends of the middle two pole columns in one of them are one S pole and the other N pole, the protruding end of the pole column on one side is N pole, and the pole column on the other side is S pole. In the pole column on one side and the adjacent middle pole column, the flow direction of the radial magnetic circuit 002 is the same as that of the axial magnetic circuit 001, so that the magnetic flux between the two pole columns and the bearing rotor 7 increases and the radial force increases. However, this is only the influence of the axial magnetic flux on the radial magnetic flux in one quadrant. In the four quadrants, the enhancement of the axial magnetic flux on the radial magnetic flux cancels each other out. That is, although both the radial magnetic circuit and the axial magnetic circuit of the integrated magnetic bearing pass through the bearing rotor 7, even if the axial magnetic circuit changes, it will not affect the overall radial magnetic circuit. Therefore, the axial magnetic circuit and the radial magnetic circuit play their respective roles, simplifying the control of the magnetic bearing. The present invention integrates the radial bearing and the axial bearing, has no thrust disk, has a compact structure, reduces the bearing size, shortens the rotor length, increases the rotor critical speed, and improves the stability and applicability of the magnetic levitation system. Compared with the case where the magnetic poles are located beside the radial stator yoke axially, the leakage magnetic flux of the radial magnetic circuit in the axial direction is reduced, and the circumferential non-uniformity of the axial output force is eliminated. With 16 pole columns, the processing and manufacturing process is simple, the radial magnetic circuit control is convenient, there is no permanent magnet, the cost is low, the assembly is convenient, the bearing capacity is large, and it can operate at high power. A plurality of the second outer pole blocks 10 are arranged at intervals along the circumferential direction of the first axial stator 1, and a plurality of the first outer pole blocks 9 are arranged at intervals along the circumferential direction of the first axial stator 1. The upper magnetic poles of the axial stator adopt a segmented structure, avoiding the leakage magnetic flux phenomenon of the radial magnetic circuit on the adjacent radial pole columns on the outer circle of the axial stator, only enhancing the air-gap magnetic field on the radial magnetic poles, having a high degree of radial and axial integration, no thrust disk, reducing the cost, having a compact structure, a simple process, a high critical speed, and stable performance. The axial coil 3 adopts a single-coil mode and is installed in the first axial stator 1 and the second axial stator 2, located at both ends of the pole columns of the radial stator 6, providing the axial magnetic circuit and controlling the axial movement of the bearing rotor 7. The radial magnetic poles adopt 16 levels and are symmetrically distributed in four └┴┴┘-shaped structures. The magnetic poles at both ends are small teeth, and the middle two magnetic poles are large teeth. The axial magnetic circuit provided in the radial direction enhances the radial air-gap magnetic field, and the influence of the axial magnetic flux on the radial magnetic flux is all positive, controlling the movement of the rotating shaft in the radial direction, and at the same time realizing the movement of the rotating shaft in three degrees of freedom in the radial and axial directions, effectively reducing the bearing volume and the rotor length, and improving the operating stability of the rotor.

[0028] In some embodiments, each set of the pole columns includes a first pole column 4, a second pole column 11, a third pole column 12, and a fourth pole column 17. The second pole column 11 and the third pole column 12 are located between the first pole column 4 and the fourth pole column 17. Moreover, the first pole column 4 and the fourth pole column 17, and the second pole column 11 and the third pole column 12 are symmetrical. The magnetic polarities of the first pole column 4 and the second pole column 11, the second pole column 11 and the third pole column 12, and the third pole column 12 and the fourth pole column 17 are opposite. In this technical solution, the first pole column 4 and the fourth pole column 17, and the second pole column 11 and the third pole column 12 are symmetrical, and the magnetic polarities of the first pole column 4 and the second pole column 11, the second pole column 11 and the third pole column 12, and the third pole column 12 and the fourth pole column 17 are opposite, resulting in three magnetic circuits: the first pole column 4 - the second pole column 11, the third pole column 12 - the second pole column 11, and the third pole column 12 - the fourth pole column 17, ensuring the strength of the radial magnetic force. The first pole column 4 and the second pole column 11 at both ends are small teeth, and the second pole column 11 and the third pole column 12 in the middle are large teeth. Each └┴┴┘-shaped structure magnetic pole is distributed as SNSN (or NSNS) in space. See Figure 2 As shown, the radial magnetic circuit 002 passes through the first pole column 4 on the └┴┴┘-shaped structure - the radial working air gap 15 - the bearing rotor 7 - the radial working clearance 15 - the second pole column 11 - the stator yoke 18 and returns to the first pole column 4 to close; the second radial magnetic circuit passes through the third pole column 12 - the radial working air gap 15 - the bearing rotor 7 - the radial working clearance 15 - the second pole column 11 - the stator yoke 18 and returns to the third pole column 12 to close; the third radial magnetic circuit passes through the third pole column 12 - the radial working air gap 15 - the bearing rotor 7 - the radial working clearance 15 - the fourth pole column 17 - the stator yoke 18 and returns to the third pole column 12 to close. See Figure 3 As shown, the magnetic poles on the axial stator adopt a segmented structure, and a single coil is wound in the internal groove. During assembly, it corresponds to the radial small teeth a and the radial large teeth c of the └┴┴┘-shaped structure. The axial magnetic circuit 001 all points to the center of the circle (or all points to the circumference), and the air gap magnetic field of the first pole column 4 and the third pole column 12 of the └┴┴┘-shaped structure is enhanced. When it is necessary to control the bearing rotor 7 to move to the upper left, the left upper radial winding is energized to provide a radial force for the bearing rotor to move to the upper left; when it is necessary to control the bearing rotor to move upward, the left and right upper radial windings are energized to provide a radial force for the bearing rotor to move upward. This control has a wide range of radial movement directions and is flexible. This three-degree-of-freedom magnetic bearing structure integrates the radial bearing and the axial bearing, has no thrust disc, is structurally compact, has a simple process, effectively reduces the bearing volume, shortens the rotor length, increases the rotor critical speed, and improves the system operation stability.

[0029] In some embodiments, the widths of the second pole column 11 and the third pole column 12 are the same, the widths of the first pole column 4 and the fourth pole column 17 are the same, and the width of the third pole column 12 is greater than the width of the fourth pole column 17. In this technical solution, the second pole column 11 and the third pole column 12 respectively act as magnetic flux components for the magnetic forces of the first pole column 4 and the fourth pole column 17. The width of the third pole column 12 being greater than the width of the fourth pole column 17 optimizes the magnetic circuits on both sides.

[0030] See Figure 3 As shown, in some embodiments, there are at least six first outer pole blocks 9. Each adjacent pair of the first pole column 4 and the second pole column 11, and each adjacent pair of the third pole column 12 and the fourth pole column 17 corresponds to one first outer pole block 9; there are at least six second outer pole blocks 10. Each adjacent pair of the first pole column 4 and the second pole column 11, and each adjacent pair of the third pole column 12 and the fourth pole column 17 corresponds to one second outer pole block 10. In this technical solution, the phenomenon of magnetic leakage of the radial magnetic circuits on the adjacent radial pole columns on the outer circle of the axial stator is avoided, and only the air-gap magnetic field on the radial pole columns is enhanced. During installation, the first outer pole block 9 (second outer pole block 10) of the axial stator and the pole columns of the radial stator 6 can be closely attached in the axial direction, or a small clearance fit can be adopted. The first outer pole blocks 9 are arranged at intervals so that this location is not close to the radial magnetic poles (pole columns). The axial magnetic circuit cannot pass through the radial magnetic poles (the second pole column 11 and the fourth pole column 17) here, thus not affecting the radial magnetic circuit in the opposite direction. It can only pass through the radial magnetic poles (the first pole column 4 and the third pole column 12) adjacent to the first outer pole blocks 9 in the same direction as the radial magnetic circuit, without affecting it, and can also prevent magnetic leakage. For example, for the radial magnetic circuits of the two magnetic poles of the first pole column 4 and the second pole column 11, from the first pole column 4 to the second pole column 11, if the magnetic poles are a complete circle in the axial direction, some radial magnetic circuits will pass through the upper magnetic poles, resulting in radial magnetic leakage.

[0031] In some embodiments, see Figure 1As shown, there is an axial inner working gap 16 between the first inner pole block 13 and the end face of the bearing rotor 7. There is an axial outer working gap between the first outer pole block 9 and the circumferential wall of the radial stator 6. The first outer pole block 9 is located radially inside the radial coil 5. There is a radial working gap 15 between the circumferential wall of the radial stator 6 and the bearing rotor 7. Specifically, an axial magnetic circuit 001 is formed among the first axial stator 1, the bearing rotor 7, and the radial stator 6. The axial magnetic circuit 001 passes through the first outer pole block 9 - the axial outer working gap - the pole column - the radial working gap 15 - the bearing rotor 7 - the axial inner working gap 16 - the first inner pole block 13 and returns to the first axial stator 1 to be closed. In this technical solution, the first outer pole block 9 is located radially inside the radial coil 5 and is not arranged corresponding to the stator yoke 18 of the radial stator 6, which can reduce the magnetic leakage of the radial magnetic circuit 002 in the axial direction and prevent the occurrence of uneven circumferential axial force output.

[0032] In some embodiments, there is an axial inner working gap 16 between the second inner pole block 14 and the end face of the bearing rotor 7. There is an axial outer working gap between the second outer pole block 10 and the circumferential wall of the radial stator 6. The second outer pole block 10 is located radially inside the radial coil 5. Specifically, an axial magnetic circuit 001 is formed among the second axial stator 2, the bearing rotor 7, and the radial stator 6. The axial magnetic circuit 001 passes through the second outer pole block 10 - the axial outer working gap - the pole column - the radial working gap 15 - the bearing rotor 7 - the axial inner working gap 16 - the second inner pole block 14 and returns to the second axial stator 2 to be closed. In this technical solution, the second outer pole block 10 is located radially inside the radial coil 5 and is not arranged corresponding to the stator yoke 18 of the radial stator 6, which can reduce the magnetic leakage of the radial magnetic circuit 002 in the axial direction and prevent the occurrence of uneven circumferential axial force output. When it is necessary to control the bearing rotor 7 to move to one side, the winding current in the first axial stator 1 is increased, and the bearing rotor 7 is subjected to a greater force to one side. On the contrary, when it is necessary to control the bearing rotor to move to the other side, the winding current of the second axial stator 2 is increased, and the bearing rotor 7 is subjected to a greater force to the other side. Thus, by controlling the magnitudes of the winding currents of the first axial stator 1 and the second axial stator 2, the axial movement of the bearing rotor 7 can be controlled.

[0033] The present invention also provides a motor, including the above-mentioned magnetic levitation active bearing

[0034] The present invention also provides a compressor, including the above-mentioned motor.

[0035] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention. The above is only the preferred implementation manner of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and variations can still be made, and these improvements and variations should also be regarded as within the protection scope of the present invention.

Claims

1. A magnetic levitation active bearing, characterized in that: Comprising: A first axial stator (1), a second axial stator (2), a radial stator (6), a bearing rotor (7) and a rotating shaft (8), the bearing rotor (7) is sleeved on the outer periphery of the rotating shaft (8), the first axial stator (1) and the second axial stator (2) are located on the outer periphery of the rotating shaft (8), and along the axial direction of the bearing rotor (7), the first axial stator (1) is located at one end of the bearing rotor (7), the second axial stator (2) is located at the other end of the bearing rotor (7), and the radial stator (6) is located on the outer periphery of the bearing rotor (7); The radial stator (6) includes a stator yoke (18), along the radial direction of the bearing rotor (7), the stator yoke (18) has 16 pole posts, and the 16 pole posts face the bearing rotor (7). In the radial cross-section of the bearing rotor (7), the 16 pole posts are divided into 4 groups of pole posts, and the 4 groups of pole posts are symmetrically distributed on the stator yoke (18). The magnetic pole polarities of two adjacent pole posts in each group of pole posts are opposite. Radial coils (5) are arranged on the 16 pole posts, and when the radial coils (5) are energized, they can generate a radial magnetic force on the bearing rotor (7) to make the bearing rotor (7) radially suspended; The first axial stator (1) includes a plurality of first outer pole blocks (9) and first inner pole blocks (13). The plurality of first outer pole blocks (9) are arranged at intervals in the circumferential direction of the first axial stator (1). An axial coil (3) is provided between the first outer pole blocks (9) and the first inner pole blocks (13). The second axial stator (2) includes a plurality of second outer pole blocks (10) and second inner pole blocks (14). An axial coil (3) is provided between the second outer pole blocks (10) and the second inner pole blocks (14). The plurality of second outer pole blocks (10) are arranged at intervals in the circumferential direction of the first axial stator (1). When the axial coil (3) is energized, an axial magnetic force can be generated on the bearing rotor (7) to axially suspend the bearing rotor (7). The plurality of first outer pole blocks and second outer pole blocks are respectively arranged corresponding to the pole columns with the same polarity among the 16 pole columns on the stator yoke (18). Each group of pole columns includes a first pole column (4), a second pole column (11), a third pole column (12), and a fourth pole column (17). The second pole column (11) and the third pole column (12) are located between the first pole column (4) and the fourth pole column (17). Moreover, the first pole column (4) and the fourth pole column (17), and the second pole column (11) and the third pole column (12) are symmetrical. The magnetic polarities of the first pole column (4) and the second pole column (11), the second pole column (11) and the third pole column (12), and the third pole column (12) and the fourth pole column (17) are opposite. The second pole column (11) and the third pole column (12) have the same width. The first pole column (4) and the fourth pole column (17) have the same width. The width of the third pole column (12) is greater than the width of the fourth pole column (17).

2. The magnetic levitation active bearing according to claim 1, wherein: The number of the first outer pole blocks (9) is at least 6. In one quadrant, each adjacent first pole column (4) and second pole column (11), and each adjacent third pole column (12) and fourth pole column (17) correspond to one first outer pole block (9). The number of the second outer pole blocks (10) is at least 6. In one quadrant, each adjacent first pole column (4) and second pole column (11), and each adjacent third pole column (12) and fourth pole column (17) correspond to one second outer pole block (10).

3. The magnetic levitation active bearing according to claim 1, wherein: There is an axial inner working gap (16) between the first inner pole block (13) and the end face of the bearing rotor (7). There is an axial outer working gap or they are in contact between the first outer pole block (9) and the peripheral wall of the radial stator (6). The first outer pole block (9) is located radially inside the radial coil (5).

4. The magnetic levitation active bearing according to claim 3, wherein: An axial magnetic circuit (001) is formed among the first axial stator (1), the bearing rotor (7), and the radial stator (6). The axial magnetic circuit (001) is closed by passing through the first outer pole block (9) - the axial outer working gap - the pole column - the bearing rotor (7) - the axial inner working gap (16) - the first inner pole block (13) and then returning to the first axial stator (1).

5. The magnetic levitation active bearing according to claim 1, wherein: An axial inner working gap (16) is provided between the second inner pole block (14) and the end face of the bearing rotor (7). An axial outer working gap is provided between the second outer pole block (10) and the circumferential wall of the radial stator (6). The second outer pole block (10) is located radially inside the radial coil (5).

6. The magnetic levitation active bearing according to claim 5, wherein: An axial magnetic circuit (001) is formed among the second axial stator (2), the bearing rotor (7), and the radial stator (6). The axial magnetic circuit (001) is closed by passing through the second outer pole block (10) - the axial outer working gap - the pole column - the bearing rotor (7) - the axial inner working gap (16) - the second inner pole block (14) and then returning to the second axial stator (2).

7. A motor, characterized in that, It includes the magnetic levitation active bearing according to any one of claims 1 to 6.

8. A compressor, characterized in that, It includes the motor according to claim 7.

Images