CN115654016A

CN115654016A - Magnetic suspension active bearing, motor and compressor

Info

Publication number: CN115654016A
Application number: CN202211259974.2A
Authority: CN
Inventors: 陈艳霞; 龚高; 张超; 董如昊
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2022-10-14
Filing date: 2022-10-14
Publication date: 2023-01-31
Anticipated expiration: 2042-10-14

Abstract

The invention provides a magnetic suspension active bearing, a motor and a compressor, wherein the magnetic suspension active bearing comprises: the rotating shaft is sleeved in the bearing rotor, the first axial stator and the second axial stator are positioned on the periphery of the rotating shaft, the first axial stator is positioned at one end of the bearing rotor, the second axial stator is positioned at the other end of the bearing rotor, and the radial stator is positioned on the periphery of the bearing rotor; radial stator includes the stator yoke, along the radial of bearing rotor, the stator yoke has 12 utmost point posts, 12 utmost point posts divide into 4 utmost point posts of group, 4 utmost point post symmetric distributions are on the stator yoke, the magnetic pole polarity of two adjacent utmost point posts in every utmost point post of group is opposite, be provided with radial coil on 12 utmost point posts, can overcome prior art journal bearing and axial bearing and integrate the not high defect of degree for need not the thrust disc of independent assembly in the pivot, the structure is compacter, the technology is simplified more.

Description

Magnetic suspension active bearing, motor and compressor

Technical Field

The invention relates to the technical field of bearings, in particular to a magnetic suspension active bearing, a motor and a compressor.

Background

The magnetic suspension bearing suspends the rotating shaft by utilizing the electromagnetic force on the rotor, and the rotating shaft and the stator are kept in a non-contact state, so that the magnetic suspension bearing has the advantages of no abrasion, high rotating speed, high precision, long service life and the like. Magnetic suspension bearings can be divided into three categories according to the working principle: active magnetic bearings, passive magnetic bearings, and hybrid magnetic bearings.

Magnetic suspension bearing comprises journal bearing, axial bearing, and axial bearing can produce axial magnetic force to the bearing rotor, so that rotor axial suspension, and journal bearing can produce radial magnetic force to the bearing rotor, so that rotor radial suspension, among the current magnetic suspension bearing, because be provided with the thrust disc on the rotor, make journal bearing and axial bearing integrate the degree not high, and magnetic suspension bearing's journal bearing and axial bearing integrate the degree not high.

Disclosure of Invention

Therefore, the magnetic suspension active bearing, the motor and the compressor provided by the invention can overcome the defect of low integration degree of a radial bearing and an axial bearing in the prior art, so that a thrust disc does not need to be independently assembled on a rotating shaft, the structure is more compact, and the process is more simplified.

In order to solve the above problems, the present invention provides a magnetic suspension active bearing, which includes:

the bearing rotor is sleeved on the periphery of the rotating shaft, the first axial stator and the second axial stator are positioned on the periphery of the rotating shaft, in addition, along the axial direction of the bearing rotor, the first axial stator is positioned at one end of the bearing rotor, the second axial stator is positioned at the other end of the bearing rotor, and the radial stator is positioned on the periphery of the bearing rotor;

the radial stator comprises a stator magnet yoke, the stator magnet yoke is provided with 12 poles along the radial direction of the bearing rotor, the 12 poles face the bearing rotor, the 12 poles are divided into 4 groups of poles on the radial section of the bearing rotor, the 4 groups of poles are symmetrically distributed on the stator magnet yoke, the magnetic poles of two adjacent poles in each group of poles are opposite in polarity, radial coils are arranged on the 12 poles, and the radial coils are electrified to generate radial magnetic force on the bearing rotor so as to enable the bearing rotor to be suspended in the radial direction;

the first axial stator comprises a plurality of first outer pole blocks and first inner pole blocks, the first outer pole blocks are arranged at intervals along the circumferential direction of the first axial stator, and axial coils are arranged between the first outer pole blocks and the first inner pole blocks; the second axial stator includes a plurality of second outer pole pieces and second inner pole pieces, the second outer pole pieces with be provided with axial coil between the second inner pole pieces, it is a plurality of the second outer pole pieces are followed the circumference interval arrangement of first axial stator, axial coil circular telegram can be right bearing rotor produces axial magnetic force, so that bearing rotor axial suspension, it is a plurality of first outer pole pieces and second outer pole pieces one-to-one respectively in the stator yoke 12 utmost point post rather than the same utmost point post setting of polarity.

In some embodiments, each of the poles includes a first pole, a second pole and a third pole, the second pole is located between the first pole and the third pole, the first pole is symmetrical to the third pole, and the polarities of the magnetic poles of the first pole and the second pole and the third pole are opposite.

In some embodiments, the first pole post and the third pole post have the same width, and the second pole post has a width greater than the width of the third pole post.

In some embodiments, the number of the first outer pole blocks is at least 4, and each of the two adjacent first pole columns and each of the two adjacent third pole columns corresponds to one first outer pole block; the second external pole piece is 4 at least, two adjacent first utmost point post, two adjacent third utmost point post all corresponds a second external pole piece respectively.

In some embodiments, the number of the first external pole pieces is at least 4, and the second pole column corresponds to one first external pole piece;

the number of the second external pole blocks is at least 4, and the second pole column corresponds to one second external pole block.

In some embodiments, the first inner pole piece has an axially inner working gap with an end face of the bearing rotor, the first outer pole piece has an axially outer working gap with the radial stator perimeter wall, and the first outer pole piece is located radially inward of the radial coils.

In some embodiments, an axial magnetic circuit is formed between the first axial stator, the bearing rotor, radial stator, which is closed through the first outer pole piece-the axially outer working gap-the pole-the bearing rotor-the axially inner working gap-the first inner pole piece back to the first axial stator.

In some embodiments, the second inner pole piece has an axially inner working gap with an end face of the bearing rotor, the second outer pole piece has an axially outer working gap with the radial stator circumferential wall, and the second outer pole piece is located radially inward of the radial coil.

In some embodiments, an axial magnetic circuit is formed between the second axial stator, the bearing rotor, and the radial stator, the axial magnetic circuit closing through the second outer pole piece-the axially outer working gap-the pole-the bearing rotor-the axially inner working gap-the second inner pole piece back to the second axial stator.

The invention also provides a motor comprising the magnetic suspension active bearing.

The invention also provides a compressor which comprises the motor.

According to the magnetic suspension active bearing, the motor and the compressor, the radial stator magnetic circuit, the first axial stator magnetic circuit and the second axial stator magnetic circuit are conducted through the bearing rotor, a thrust disc does not need to be designed on the rotating shaft, the integration degree of the bearing is further improved, the overall structure and the processing and manufacturing process of the bearing are simplified, the assembly is convenient, the integration degree is higher, the structure is more compact, the size of the bearing is effectively reduced, the length of the rotating shaft is shortened, the critical rotating speed of the rotor is improved, and the operation stability of a magnetic suspension system is improved; 4 group's utmost point post is NSN or SNS and distributes, every group the magnetic pole polarity of two adjacent utmost point posts in the utmost point post is opposite, and the electromagnetic force that two adjacent utmost point posts produced is located the middle part of utmost point post all the time, can guarantee the pivot in radial ascending position, and is a plurality of first outer utmost point piece interval arrangement, just, first outer utmost point piece and 12 utmost point post is relative, avoids the magnetic leakage phenomenon of radial magnetic circuit on the axial stator excircle on adjacent radial utmost point post.

Drawings

FIG. 1 is a cross-sectional view of a magnetically levitated active bearing of an embodiment of the present invention;

FIG. 2 is a front view of a magnetically levitated active bearing of an embodiment of the present invention;

FIG. 3 is a top view of an axial stator in a magnetically levitated active bearing of an embodiment of the present invention;

FIG. 4 is a front view of an axial stator in a magnetic levitation active bearing according to an embodiment of the present invention;

fig. 5 is a front view of an axial stator in a magnetically levitated active bearing according to another embodiment of the present invention.

The reference numbers are given as:

1. a first axial stator; 2. a second axial stator; 3. an axial coil; 4. a first pole column; 5. a radial coil; 6. a radial stator; 7. a bearing rotor; 8. a rotating shaft; 9. a first outer pole piece; 10. a second outer pole block; 11. a second pole; 12. a third pole; 13. a first inner pole piece; 14. a second inner pole piece; 15. a radial working gap; 16. an axial inboard working gap; 17. a stator yoke; 001. an axial magnetic circuit; 002. a radial magnetic path.

Detailed Description

Referring to fig. 1 to 4 in combination, there is provided a magnetic suspension active bearing, including: the stator comprises a first axial stator 1, a second axial stator 2, a radial stator 6, a bearing rotor 7 and a rotating shaft 8, wherein the bearing rotor 7 is sleeved on the periphery of the rotating shaft 8, the first axial stator 1 and the second axial stator 2 are positioned on the periphery of the rotating shaft 8, in addition, along the axial direction of the bearing rotor 7, the first axial stator 1 is positioned at one end of the bearing rotor 7, the second axial stator 2 is positioned at the other end of the bearing rotor 7, and the radial stator 6 is positioned on the periphery of the bearing rotor 7; the radial stator 6 comprises a stator yoke 17, the stator yoke 17 has 12 poles along the radial direction of the bearing rotor 7, the 12 poles face the bearing rotor 7, on the radial cross section of the bearing rotor 7, the 12 poles are divided into 4 groups of poles, the 4 groups of poles are symmetrically distributed on the stator yoke 17, the magnetic poles of two adjacent poles in each group of poles are opposite in polarity, radial coils 5 are arranged on the 12 poles, and the radial coils 5 are electrified to generate radial magnetic force on the bearing rotor 7 so as to enable the bearing rotor 7 to radially suspend; the first axial stator 1 comprises a plurality of first outer pole blocks 9 and first inner pole blocks 13, the first outer pole blocks 9 are arranged at intervals along the circumferential direction of the first axial stator 1, and axial coils 3 are arranged between the first outer pole blocks 9 and the first inner pole blocks 13; the second axial stator 2 comprises a plurality of second outer pole blocks 10 and second inner pole blocks 14, axial coils 3 are arranged between the second outer pole blocks 10 and the second inner pole blocks 14, the second outer pole blocks 10 are arranged along the circumferential direction of the first axial stator 1 at intervals, and the axial coils 3 are electrified to generate axial magnetic force for the bearing rotor 7 to axially suspend the bearing rotor 7. The first external pole blocks and the second external pole blocks are respectively arranged in a one-to-one correspondence manner with the poles with the same polarity in the 12 poles on the stator magnetic yoke 17. In the technical scheme, a radial stator 6 magnetic circuit, a first axial stator 1 magnetic circuit and a second axial stator 2 magnetic circuit are all conducted through a bearing rotor 7, a thrust disc does not need to be designed on a rotating shaft 8, the integration degree of a bearing is further improved, the whole structure and the processing and manufacturing process of the bearing are simplified, the bearing is convenient to assemble, the integration degree is higher, the structure is more compact, the size of the bearing is effectively reduced, the length of the rotating shaft is shortened, the critical rotating speed of the rotor is improved, and the operation stability of a magnetic suspension system is improved; 4 group's utmost point post is E shape structure, is NSN or SNS and distributes, every group the magnetic pole polarity of two adjacent utmost point posts is opposite in the utmost point post, and the electromagnetic force that two adjacent utmost point posts produced is located the middle part of utmost point post all the time, can guarantee pivot 8 position radial ascending, and is a plurality of 9 interval arrangements of first outer utmost point piece, just, 9 and 12 of first outer utmost point piece are relative, exempt from the magnetic leakage phenomenon of radial magnetic circuit on the axial stator excircle on the adjacent radial utmost point post. Referring to fig. 2, in the radial coil 5 of any set of poles, one of the protruding ends of the middle pole is an S pole, the protruding end of one pole is an N pole, and the other pole is an N pole, the flow direction of the radial magnetic path 002 in one pole and the adjacent middle pole is the same as the flow direction of the axial magnetic path 001, so that the magnetic fluxes between the two poles and the bearing rotor 7 are increased, and the radial force is increased, but the radial magnetic flux in one quadrant is only the influence of the axial magnetic flux on the radial magnetic flux, and the radial magnetic flux in the four quadrants is mutually offset, that is, although the radial magnetic path and the axial magnetic path of the integrated magnetic bearing both flow through the bearing rotor 7, the axial magnetic path does not influence the whole radial magnetic path even if changed, so that the axial magnetic path and the radial magnetic path respectively play their roles, and the control of the magnetic bearing is simplified. The invention integrates the radial bearing and the axial bearing, has no thrust disc, has compact structure, reduces the size of the bearing, shortens the length of the rotor, improves the critical rotating speed of the rotor and improves the stability and the applicability of a magnetic suspension system. Compared with the axial magnetic pole positioned beside a radial stator magnetic yoke, the axial magnetic pole has the advantages that the magnetic flux leakage of the radial magnetic circuit in the axial direction is reduced, the condition of nonuniform circumferential force applied axially is avoided, 12 pole columns are adopted, the processing and manufacturing process is simple, the radial magnetic circuit is convenient to control, no permanent magnet is provided, the cost is low, the assembly is convenient, the bearing capacity is large, the axial magnetic pole can run in a high-power mode, the second outer pole blocks 10 are arranged along the circumferential interval of the first axial stator 1, the first outer pole blocks 9 are arranged along the circumferential interval of the first axial stator 1, the magnetic pole on the axial stator adopts a block structure, the magnetic flux leakage phenomenon of the radial magnetic circuit on the excircle of the axial stator on the adjacent radial pole columns is avoided, only the air gap magnetic field on the radial magnetic pole is enhanced, the radial axial integration is high, no thrust disc exists, the cost is reduced, the structure is compact, the process is simple, the critical rotation speed is high, and the performance is stable. The axial coil 3 adopts a single coil mode, is installed in the first axial stator 1 and the second axial stator 2, is positioned at two ends of a polar column of the radial stator 6, provides an axial magnetic circuit, controls the axial movement of the bearing rotor 7, adopts 12-level radial magnetic poles, is four E-shaped structures which are symmetrically distributed, the magnetic poles at two ends are small teeth, the middle magnetic pole is a large tooth, the radial air gap magnetic field is enhanced by the axial magnetic circuit provided in the radial direction, the axial magnetic flux has positive influence on the radial magnetic flux, the radial movement of the rotating shaft in the radial direction is controlled, the radial movement of the rotating shaft in three degrees of freedom in the radial direction and the axial direction is realized at the same time, the bearing volume and the rotor length are effectively reduced, and the operation stability of the rotor is improved.

In some embodiments, each set of poles includes a first pole 4, a second pole 11 and a third pole 12, the second pole 11 is located between the first pole 4 and the third pole 12, and the first pole 4 is symmetrical to the third pole 12, and the magnetic poles of the first pole 4 and the second pole 11, the second pole 11 and the third pole 12 are opposite. In the technical scheme, two magnetic circuits of the first pole post 4, the second pole post 11, the third pole post 12 and the second pole post 11 are generated, and the strength of radial magnetic force is ensured. The first pole 4 and the third pole 12 at two ends are small teeth, the second pole 11 in the middle is a large tooth, radial windings on the small teeth at two ends are connected in series, each E-shaped structure magnetic pole is distributed in NSN (or SNS) in space, and referring to fig. 2, a radial magnetic circuit 002 returns to the first pole 4 to be closed through the first pole 4, a radial working air gap 15, a bearing rotor 7, a radial working gap 15, the second pole 11 and a stator magnetic yoke 17 on the E-shaped structure; the second radial magnetic circuit returns to the third pole 12 through the third pole 12, the radial working air gap 15, the bearing rotor 7, the radial working gap 15, the second pole 11 and the stator magnetic yoke 17 to be closed; referring to fig. 3, the upper magnetic pole of the axial stator adopts a block structure, a single coil is wound in the inner groove, the axial stator corresponds to the small tooth structure of the radial stator during assembly, the axial magnetic circuit 001 points to the circle center (or points to the circumference) completely, and the air gap magnetic field of the small teeth at the two ends of the E-shaped structure is enhanced. When the bearing rotor 7 needs to be controlled to move towards the left upper side, the radial winding at the left upper side is electrified to provide a radial force of the bearing rotor towards the left upper side; when the bearing rotor needs to be controlled to move upwards, the left upper radial winding and the right upper radial winding are electrified to provide upward radial force for the bearing rotor, and the control of the radial direction is wide in moving direction and flexible in control. The three-degree-of-freedom magnetic bearing structure integrates the radial bearing and the axial bearing, has no thrust disc, is compact in structure and simple in process, effectively reduces the volume of the bearing, shortens the length of a rotor, improves the critical rotating speed of the rotor, and improves the running stability of a system.

In some embodiments, the width of the first pole post 4 is the same as the width of the third pole post 12, and the width of the second pole post 11 is greater than the width of the third pole post 12. In this technical solution, the second pole post 11 acts on the magnetic force circulating member between the first pole post 4 and the fourth pole post 17, and the width of the second pole post 11 is greater than that of the third pole post 12, so that the magnetic paths on both sides are optimized.

Referring to fig. 3, in some embodiments, the number of the first outer pole blocks 9 is at least 4, and each of the two adjacent first poles 4 and the two adjacent third poles 12 corresponds to one first outer pole block 9; the number of the second external pole blocks 10 is at least 4, and the adjacent two first poles 4 and the adjacent two third poles 11 respectively correspond to one second external pole block 10. In the technical scheme, the magnetic flux leakage phenomenon of a radial magnetic circuit on an adjacent radial pole on the excircle of the axial stator is avoided, and only an air gap magnetic field on the radial pole is enhanced. First outer pole piece 9 interval arrangement is for making this place not be close to radial magnetic pole, thereby axial magnetic circuit can not follow this place radial magnetic pole (second utmost point post 11, third utmost point post 12) and go up through can not influence the radial magnetic circuit who walks the opposite direction, can only follow radial magnetic pole (first utmost point post 4, third utmost point post 12) that the arch is close to and pass through unanimously with radial magnetic circuit direction, can not lead to the fact the influence to it, and can also prevent the magnetic leakage, for example first utmost point post 4, the first utmost point post 4 of two magnetic pole radial magnetic circuits of second utmost point post 11 → second utmost point post 11, the magnetic pole is the whole circle in the axial can lead to having partial radial magnetic circuit to follow the magnetic pole and pass through, there is radial magnetic leakage. The axial magnetic circuit only enhances the radial magnetic circuit (positive effect), and the air gap magnetic field of the enhanced radial small teeth acts in a single quadrant.

Referring to fig. 4, in some embodiments, the number of the first outer pole pieces 9 is at least 4, and the second pole 11 corresponds to one first outer pole piece 9; the number of the second external pole blocks 10 is at least 4, and the second pole column 11 corresponds to one second external pole block 10. In the technical scheme, different assembly structures are provided, the magnetic leakage phenomenon of a radial magnetic circuit on an adjacent radial pole on the excircle of the axial stator is avoided, and only an air gap magnetic field on the radial pole is enhanced. When the stator is installed, the first outer pole block 9 (the second outer pole block 10) of the axial stator and the pole of the radial stator 6 can be tightly attached in the axial direction, and small clearance fit can also be adopted. A first outer pole block 9 (a second outer pole block 10) on the axial stator adopts a block structure, a single coil is wound in an inner groove, the single coil corresponds to a second pole column 11 and a first pole column 4 of an E-shaped structure during assembly, an axial magnetic circuit points to the circumference (or points to the circle center) completely, and an air gap magnetic field of the second pole column 11 and the first pole column 4 of the E-shaped structure is enhanced.

In some embodiments, referring to fig. 1, an axially inner working gap 16 is provided between the first inner pole piece 13 and the end face of the bearing rotor 7, an axially outer working gap is provided between the first outer pole piece 9 and the circumferential wall of the radial stator 6, and the first outer pole piece 9 is located radially inward of the radial coil 5. A radial working gap 15 is provided between the radial stator 6 and the outer peripheral wall of 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, and the axial magnetic circuit 001 passes through the first outer pole piece 9, the axially outer working gap, the pole, the radial working gap 15, the bearing rotor 7, the axially inner working gap 16, and the first inner pole piece 13 to return to the first axial stator 1 to be closed. In the technical scheme, the first external pole block 9 is located on the radial inner side of the radial coil 5 and is not arranged corresponding to the stator magnetic yoke 17 of the radial stator 6, so that the magnetic leakage of the radial magnetic circuit 002 in the axial direction can be reduced, and the occurrence of the circumferential uneven condition of axial force output is avoided.

In some embodiments, the second inner pole piece 14 has an axially inner working gap 16 with the end face of the bearing rotor 7, the second outer pole piece 10 has an axially outer working gap with the circumferential wall of the radial stator 6, and the second outer pole piece 10 is located radially inward of 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, and the axial magnetic circuit 001 returns to the second axial stator 2 to be closed through the second outer pole piece 10, the axial outer working gap, the pole column, the radial working gap 15, the bearing rotor 7, the axial inner working gap 16 and the second inner pole piece 14. In this technical scheme, the second external pole piece 10 is located radial coil 5's radial inboard, and does not correspond the setting with radial stator 6's stator yoke 17, can reduce radial magnetic circuit 002 in the magnetic leakage of axial direction, stops the emergence of the inhomogeneous condition of axial output circumference. When the bearing rotor 7 needs to be controlled to move towards one side, the winding current in the first axial stator 1 is increased, and the force applied to the bearing rotor 7 towards one side is large, on the contrary, when the bearing rotor needs to be controlled to move towards the other side, the winding current of the second axial stator 2 is increased, and the force applied to the bearing rotor 7 towards the other side is large, so that the axial movement of the bearing rotor 7 is controlled by controlling the winding current of the first axial stator 1 and the winding current of the second axial stator 2.

The invention also provides a motor which comprises the magnetic suspension active bearing.

The invention also provides a compressor which comprises the motor.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention. The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.

Claims

1. A magnetic suspension active bearing is characterized in that: the method comprises the following steps: the bearing comprises a first axial stator (1), a second axial stator (2), a radial stator (6), a bearing rotor (7) and a rotating shaft (8), wherein the bearing rotor (7) is sleeved on the periphery of the rotating shaft (8), the first axial stator (1) and the second axial stator (2) are positioned on the periphery of the rotating shaft (8), in addition, along the axial direction of the bearing rotor (7), the first axial stator (1) is positioned at one end of the bearing rotor (7), the second axial stator (2) is positioned at the other end of the bearing rotor (7), and the radial stator (6) is positioned on the periphery of the bearing rotor (7);

the radial stator (6) comprises a stator magnet yoke (17), the stator magnet yoke (17) is provided with 12 poles along the radial direction of the bearing rotor (7), the 12 poles face the bearing rotor (7), on the radial cross section of the bearing rotor (7), the 12 poles are divided into 4 groups of poles, the 4 groups of poles are symmetrically distributed on the stator magnet yoke (17), the magnetic poles of two adjacent poles in each group of poles are opposite in polarity, radial coils (5) are arranged on the 12 poles, and the radial coils (5) are electrified to generate radial magnetic force on the bearing rotor (7) so as to enable the bearing rotor (7) to radially suspend;

the first axial stator (1) comprises a plurality of first outer pole blocks (9) and first inner pole blocks (13), the first outer pole blocks (9) are arranged at intervals along the circumferential direction of the first axial stator (1), and axial coils (3) are arranged between the first outer pole blocks (9) and the first inner pole blocks (13); second axial stator (2) includes a plurality of second outer pole piece (10) and second inner pole piece (14), second outer pole piece (10) with be provided with axial coil (3) between second inner pole piece (14), it is a plurality of second outer pole piece (10) are followed the circumference interval arrangement of first axial stator (1), axial coil (3) circular telegram can be right bearing rotor (7) produce axial magnetic force, so that bearing rotor (7) axial suspension, it is a plurality of first outer pole piece and second outer pole piece respectively one-to-one in 12 utmost point posts on stator yoke (17) rather than the utmost point post setting that the polarity is the same.

2. The magnetic levitation active bearing of claim 1, wherein: every group the utmost point post includes first utmost point post (4), second utmost point post (11) and third utmost point post (12), second utmost point post (11), be located first utmost point post (4) with between third utmost point post (12), just, first utmost point post (4) with third utmost point post (12) are symmetrical, first utmost point post (4) with second utmost point post (11) with the magnetic pole polarity of third utmost point post (12) is opposite.

3. The magnetic levitation active bearing of claim 2, wherein: the width of the first pole column (4) is the same as that of the third pole column (12), and the width of the second pole column (11) is larger than that of the third pole column (12).

4. The magnetic levitation active bearing of claim 2, wherein: the number of the first outer pole blocks (9) is at least 4, and two adjacent first poles (4) and two adjacent third poles (12) respectively correspond to one first outer pole block (9);

the number of the second external pole blocks (10) is at least 4, and the adjacent two first poles (4) and the adjacent two third poles (11) respectively correspond to one second external pole block (10).

5. The magnetic levitation active bearing of claim 2, wherein: the number of the first external pole blocks (9) is at least 4, and the second pole column (11) corresponds to one first external pole block (9);

the number of the second external pole blocks (10) is at least 4, and the second pole column (11) corresponds to one second external pole block (10).

6. The magnetic levitation active bearing of claim 1, wherein: an axial inner side working gap (16) is formed between the first inner pole block (13) and the end face of the bearing rotor (7), an axial outer side working gap or connection is formed between the first outer pole block (9) and the peripheral wall of the radial stator (6), and the first outer pole block (9) is located on the radial inner side of the radial coil (5).

7. The magnetic levitation active bearing of claim 6, wherein: an axial magnetic circuit (001) is formed among the first axial stator (1), the bearing rotor (7) and the radial stator (6), and the axial magnetic circuit (001) passes 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 returns to the first axial stator (1) to be closed.

8. The magnetic levitation active bearing of claim 1, wherein: an axial inner working gap (16) is formed between the second inner pole block (14) and the end face of the bearing rotor (7), an axial outer working gap is formed between the second outer pole block (10) and the peripheral wall of the radial stator (6), and the second outer pole block (10) is located on the radial inner side of the radial coil (5).

9. The magnetic levitation active bearing of claim 8, wherein: an axial magnetic circuit (001) is formed among the second axial stator (2), the bearing rotor (7) and the radial stator (6), and the axial magnetic circuit (001) returns to the second axial stator (2) to be closed through the second outer pole block (10) -the axial outer working gap-the pole-the bearing rotor (7) -the axial inner working gap (16) -the second inner pole block (14).

10. An electrical machine comprising a magnetically levitated active bearing as claimed in any one of claims 1 to 9.

11. A compressor, comprising the motor of claim 10.