CN210135170U

CN210135170U - Magnetic suspension bearing, motor, compressor and air conditioner

Info

Publication number: CN210135170U
Application number: CN201920884861.9U
Authority: CN
Inventors: 谭建明; 胡余生; 陈彬; 张小波; 张芳; 龚高; 吴瑞
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2019-06-12
Filing date: 2019-06-12
Publication date: 2020-03-10
Anticipated expiration: 2029-06-12

Abstract

The application provides a magnetic suspension bearing, a motor, a compressor and an air conditioner. The magnetic suspension bearing comprises an axial bearing, wherein the axial bearing comprises an inner axial iron core, an outer axial iron core, a second permanent magnet, a first control winding and a second control winding, the inner axial iron core and the outer axial iron core are coaxially arranged, the second permanent magnet is arranged in a radial gap, the second permanent magnet is radially magnetized, the first control winding is wound in the radial gap and is located at a first end of the second permanent magnet, and the second control winding is wound in the radial gap and is located at a second end of the second permanent magnet. According to the magnetic suspension bearing, the motor, the compressor and the air conditioner, the problem that the magnetic suspension bearing fails due to the fact that the control winding of the two-end axial bearing in one direction breaks down can be solved.

Description

Magnetic suspension bearing, motor, compressor and air conditioner

Technical Field

The application belongs to the technical field of motors, and particularly relates to a magnetic suspension bearing, a motor, a compressor and an air conditioner.

Background

The magnetic suspension bearing has a series of excellent qualities of no contact, no abrasion, high rotating speed, high precision, no need of lubrication and sealing and the like, and is a high and new technical product integrating electromagnetism, electronic technology, control engineering, signal processing and mechanics.

The magnetic bearing is divided into three types of active type, passive type and mixed type, the active type magnetic bearing has high rigidity and can be precisely controlled, but the volume and the power consumption required for generating unit bearing capacity are large; the passive magnetic bearing realizes the suspension of the rotor by utilizing the attraction force or the repulsion force between magnetic materials, and has lower rigidity and damping; the hybrid magnetic bearing uses a permanent magnet to provide a bias magnetic field to replace a static bias magnetic field generated by an electromagnet in an active magnetic bearing, reduces the ampere-turns of a control winding, reduces the volume of the bearing, improves the bearing capacity of the bearing and the like; the hybrid magnetic bearing has irreplaceable advantages in the field with strict requirements on volume and power consumption, and is mainly applied to high-speed and ultra-high-speed occasions. Therefore, the integration and miniaturization of the magnetic levitation system and the improvement of the stability and reliability of the control system will be the key research directions.

In the control of the axial degree of freedom of the magnetic suspension system, a typical control mode is a middle thrust disk and two-end axial bearings, and the axial stability of the thrust disk is controlled by utilizing the suction force of the two-end axial bearings to the thrust disk in opposite directions.

SUMMERY OF THE UTILITY MODEL

Therefore, the technical problem to be solved by the application is to provide a magnetic suspension bearing, a motor, a compressor and an air conditioner, and the problem that the magnetic suspension bearing fails due to the fact that a control winding of one direction of axial bearings at two ends breaks down can be solved.

In order to solve the above problem, the present application provides a magnetic suspension bearing, including the axial bearing, the axial bearing includes interior axial iron core, outer axial iron core, the second permanent magnet, first control winding and second control winding, interior axial iron core and outer axial iron core coaxial setting, the second permanent magnet sets up in the radial clearance between interior axial iron core and the outer axial iron core, the second permanent magnet radially magnetizes, first control winding coiling is in the radial clearance to be located the first end of second permanent magnet, the second control winding coiling is in the radial clearance, and be located the second end of second permanent magnet.

Preferably, the second permanent magnet is a permanent magnet ring.

Preferably, an insulating framework is further arranged in the radial gap, and the first control winding and the second control winding are wound on the insulating framework.

Preferably, the insulating skeleton cooperates with the second permanent magnet to completely separate the inner axial core from the outer axial core.

Preferably, the outer circumferential wall of the inner axial core is provided with a first stopping protrusion, the inner circumferential wall of the outer axial core is provided with a second stopping protrusion, the first end of the second permanent magnet is stopped on the first stopping protrusion, and the second end of the second permanent magnet is stopped on the second stopping protrusion.

Preferably, the first stop projection and/or the second stop projection is an annular projection.

Preferably, the outer fixed sleeve of the axial bearing is provided with a shell.

Preferably, the first control winding and the second control winding are energized in the same direction.

Preferably, the first control winding and the second control winding are each independently controlled.

Preferably, the magnetic suspension bearing further comprises a rotor assembly, and two ends of the axial bearing are respectively provided with a thrust disc, and the thrust discs are fixedly arranged on the rotor assembly.

Preferably, the magnetic suspension bearing further includes a radial bearing, and the radial bearing is sleeved on the inner peripheral side of the inner axial iron core.

Preferably, the radial bearing includes stator module and rotor module, stator module includes stator core, the rotor module cover is established at stator module's inner periphery side, stator core's axial direction's middle part is provided with the first permanent magnet that is used for producing the bias magnetic field, first permanent magnet radially magnetizes, stator core's interior perisporium first end is provided with the first control magnetic pole of control, the first control magnetic pole is used for controlling rotor module along first straight reciprocating motion, stator core's interior perisporium second end is provided with the second control magnetic pole, the second control magnetic pole is used for controlling rotor module along second straight reciprocating motion, first straight line is located the first plane, the second straight line is located the second plane, first plane and second plane are different planes, first plane and second plane perpendicular to stator core's the central axis.

Preferably, a first control magnetic field for controlling the rotor assembly to reciprocate along a first straight line is formed among the first permanent magnet, the stator core, the first control magnetic pole and the rotor assembly, and the first control magnetic field is positioned at a first end of the first permanent magnet; and a second control magnetic field for controlling the rotor assembly to reciprocate along a second straight line is formed among the first permanent magnet, the stator core, the second control magnetic pole and the rotor assembly, and the second control magnetic field is positioned at the second end of the first permanent magnet.

Preferably, the first control magnetic pole comprises first iron cores arranged at the first end of the stator iron core and first coils wound on the first iron cores, the two first iron cores are positioned at two ends of the same diameter of the stator iron core, and the first iron cores are protruded from the inner peripheral wall of the stator iron core to the central axis of the stator iron core in the radial direction; and/or, the second control magnetic pole is including setting up the second iron core at stator core second end tip and around establishing the second coil on the second iron core, and two second iron cores are located stator core's the both ends of same diameter, and the second iron core is from stator core's internal perisporium radial to stator core's the central axis protrusion.

Preferably, the first permanent magnet includes four ring segments, the four ring segments are evenly distributed along the circumference of the inner circumference of the stator core, two opposite ring segments are located on a first straight line, and the other two opposite ring segments are located on a second straight line.

Preferably, the stator core comprises an inner core and control magnetic pole sections located at two ends of the inner core, and at least one control magnetic pole section is arranged separately from the inner core.

Preferably, stator module still includes the casing, and the casing cover is established at stator core periphery, and the both ends of casing are provided with axial limit structure respectively, and stator core passes through axial limit structure axial spacing in the casing.

Preferably, the housing is sleeved and fixed to the inner ring of the inner axial core.

According to another aspect of the present application, there is provided an electric machine comprising a magnetic bearing, the magnetic bearing being the magnetic bearing described above.

According to another aspect of the present application, there is provided a compressor comprising a magnetic bearing, wherein the magnetic bearing is the magnetic bearing described above.

According to another aspect of the present application, there is provided an air conditioner comprising a magnetic suspension bearing, wherein the magnetic suspension bearing is the magnetic suspension bearing described above.

The application provides a magnetic suspension bearing, including axial bearing, axial bearing includes interior axial core, outer axial core, the permanent magnet, first control winding and second control winding, interior axial core and the coaxial setting of outer axial core, in the radial clearance between axial core and the outer axial core including the permanent magnet setting, the permanent magnet radially magnetizes, first control winding coiling is in radial clearance, and be located the first end of permanent magnet, second control winding coiling is in radial clearance, and be located the second end of permanent magnet. This magnetic suspension bearing is at the during operation, owing to adopted permanent magnetism biasing structure, consequently can provide the axial magnetic field effect of continuous stability through the permanent magnet, first control winding and second control winding only are used for controlling the balanced magnetic force size at magnetic suspension bearing axial direction both ends, even in the course of the work because the trouble leads to one of them control winding or two control windings all to break down, still can make magnetic suspension bearing effective work through the biasing magnetic field that the permanent magnet provided, avoid magnetic suspension bearing inefficacy, avoid high-speed rotatory pivot emergence uncontrolled potential safety hazard, improve magnetic suspension system's stability and reliability.

Drawings

FIG. 1 is a schematic cross-sectional view of a radial bearing of a magnetic suspension bearing according to an embodiment of the present application;

FIG. 2 is a schematic perspective view of a radial bearing of a magnetic suspension bearing according to an embodiment of the present application;

FIG. 3 is an exploded view of a radial bearing of a magnetic suspension bearing according to an embodiment of the present application;

FIG. 4 is a schematic cross-sectional view of an axial bearing of a magnetic suspension bearing according to an embodiment of the present application;

FIG. 5 is a schematic perspective view of an axial bearing of a magnetic suspension bearing according to an embodiment of the present application;

FIG. 6 is an exploded view of an axial bearing of a magnetic suspension bearing according to an embodiment of the present application

FIG. 7 is a schematic view of a radial bearing and an axial bearing combination of a magnetic suspension bearing according to an embodiment of the present application;

FIG. 8 is a perspective view of a radial bearing and axial bearing assembly of a magnetic suspension bearing according to an embodiment of the present application;

FIG. 9 is an exploded view of the radial bearing and axial bearing assembly of the magnetic suspension bearing of the embodiment of the present application;

FIG. 10 is a magnetic circuit diagram of radial bearing vertical movement control of the magnetic suspension bearing according to the embodiment of the present application;

FIG. 11 is a magnetic circuit diagram of the radial bearing horizontal movement control of the magnetic suspension bearing according to the embodiment of the present application;

fig. 12 is a left side view structural view of a radial bearing of the magnetic bearing of the embodiment of the present application;

fig. 13 is a right side structural view of a radial bearing of the magnetic bearing of the embodiment of the present application;

FIG. 14 is a magnetic circuit diagram of an axial bearing of the magnetic bearing according to the embodiment of the present application;

FIG. 15 is a magnetic circuit diagram of a radial bearing and axial bearing combination structure of a magnetic suspension bearing according to an embodiment of the present application;

fig. 16 is a schematic view of a multiple degree of freedom suspension structure of a magnetic suspension bearing according to an embodiment of the present application.

The reference numerals are represented as:

1. a radial bearing; 2. a stator assembly; 3. a rotor assembly; 4. a stator core; 5. a first permanent magnet; 6. a first iron core; 7. a first coil; 8. a second iron core; 9. a second coil; 10. a fixed mount; 11. fixing grooves; 12. an inner core; 13. controlling the magnetic pole section; 14. a housing; 15. a stop flange; 16. an axial baffle; 17. an axial bearing; 18. a thrust plate; 19. a stop ring; 20. an inner axial core; 21. an outer axial core; 22. a second permanent magnet; 23. a first control winding; 24. a second control winding; 25. a radial gap; 26. an insulating framework; 27. a first stopper projection; 28. a second stopper projection; 29. a housing.

Detailed Description

Referring to fig. 1 to 3 and 10 to 13 in combination, according to an embodiment of the present application, a magnetic suspension bearing includes a radial bearing 1, the radial bearing 1 includes a stator assembly 2 and a rotor assembly 3, the stator assembly 2 includes a stator core 4, the rotor assembly 3 is sleeved on an inner circumferential side of the stator assembly 2, a first permanent magnet 5 for generating a bias magnetic field is disposed in a middle portion of an axial direction of the stator core 4, the first permanent magnet 5 is magnetized in a radial direction, a first end of an inner circumferential wall of the stator core 4 is provided with a first control magnetic pole for controlling the rotor assembly 3 to reciprocate along a first straight line, a second end of the inner circumferential wall of the stator core 4 is provided with a second control magnetic pole for controlling the rotor assembly 3 to reciprocate along a second straight line, the first straight line is located in a first plane, the second straight line is located in a second plane, the first plane and the second plane are different from each other, the first plane and the second plane are perpendicular to the central axis of the stator core 4.

The radial bearing 1 of the magnetic suspension bearing is characterized in that a first control magnetic pole is arranged on a stator iron core 4 at the first end of a first permanent magnet 5, a second control magnetic pole is arranged on the stator iron core 4 at the second end of the first permanent magnet 5, the first control magnetic pole is independently used for controlling the reciprocating motion on a first straight line, the second control magnetic pole is independently used for controlling the reciprocating motion on a second straight line, the first straight line and the second straight line are mutually vertical, so that the motion control of the first control magnetic pole on a rotor assembly 3 and the motion control of the second control magnetic pole on the rotor assembly 3 are mutually independent, and the control magnetic circuits for controlling the motion of the rotor assembly 3 on the first straight line and the second straight line can not be coupled, so that the suction force in the first straight line direction and the suction force in the second straight line direction with different sizes can be provided according to requirements, the system control is convenient, the stability and the reliability of the magnetic suspension radial control system are improved.

Preferably, the first line extends in a horizontal direction and the second line extends in a vertical direction.

Specifically, in the present embodiment, the first control magnetic pole is used to control the displacement of the rotor assembly 3 in the horizontal direction, and the second control magnetic pole is used to control the displacement of the rotor assembly 3 in the vertical direction, so that the levitation control of the rotor assembly 3 in two degrees of freedom in the horizontal direction and two degrees of freedom in the vertical direction can be realized by the mutual cooperation of the first control magnetic pole and the second control magnetic pole. The mutual cooperation here means, to the cooperation of 3 direction of motion control of rotor subassembly, from the analysis on the control magnetic circuit, the control magnetic circuit of first control magnetic pole and second control magnetic pole is mutually independent and mutually noninterfere, the magnetic line of force that first control magnetic pole produced also does not interfere with the magnetic line of force that the second control magnetic pole produced mutually, consequently can not take place the coupling between the control magnetic circuit that produces between the two, can reduce the control degree of difficulty of adjusting at horizontal direction or vertical direction displacement to rotor subassembly 3, improve control accuracy and control efficiency.

In the actual control process, due to the difference of application environments and the difference of displacement control to be realized, the first straight line is not necessarily horizontal, the second straight line is not necessarily vertical, and the first straight line and the second straight line are only required to be ensured to be vertical to each other.

A first control magnetic field for controlling the rotor assembly 3 to reciprocate along a first straight line is formed among the first permanent magnet 5, the stator iron core 4, the first control magnetic pole and the rotor assembly 3, and the first control magnetic field is positioned at the first end of the first permanent magnet 5; a second control magnetic field for controlling the rotor assembly 3 to reciprocate along a second straight line is formed among the first permanent magnet 5, the stator core 4, the second control magnetic pole and the rotor assembly 3, and the second control magnetic field is positioned at the second end of the first permanent magnet 5.

In this embodiment, the first permanent magnet 5, the stator core 4, the first control magnetic pole and the rotor assembly 3 form a first control magnetic field, the first permanent magnet 5, the stator core 4, the second control magnetic pole and the rotor assembly 3 form a second control magnetic field, and the two control magnetic fields are separated by the first permanent magnet 5, so that interference between the two control magnetic fields is avoided, and a control program of the control magnetic fields is simplified. The N pole of the first permanent magnet 5 is located on the radial inner side of the first permanent magnet 5, the S pole is located on the radial outer side of the first permanent magnet 5, the N pole of the first permanent magnet 5 can be arranged on the radial outer side of the first permanent magnet 5, and the S pole is located on the radial inner side of the first permanent magnet 5 and can be specifically arranged as required.

The first control magnetic pole comprises a first iron core 6 arranged at the end part of the first end of the stator iron core 4 and a first coil 7 wound on the first iron core 6, the two first iron cores 6 are positioned at two ends of the same diameter of the stator iron core 4, and the first iron cores 6 protrude from the inner peripheral wall of the stator iron core 4 to the central axis of the stator iron core 4 in the radial direction. Preferably, the two first coils 7 are controlled independently of each other. Because the two first coils 7 are controlled independently, when the magnetic suspension bearing works, if one first coil 7 fails, the two first coils 7 are opposite to each other, so that the other first coil 7 can still continuously realize the control function in the horizontal direction, and the adjustment of the displacement of the rotor assembly 3 in the horizontal direction can still be conveniently realized by controlling the current magnitude and direction in the other first coil 7, so that the fault tolerance is higher, and the stability and the reliability of the magnetic suspension bearing can be more effectively improved.

The second control magnetic pole includes second iron core 8 that sets up in stator core 4 second end tip and around establishing the second coil 9 on second iron core 8, and two second iron cores 8 are located the both ends of the same diameter of stator core 4, and second iron core 8 is radial to the central axis protrusion of stator core 4 from the internal perisporium of stator core 4. Preferably, the two second coils 9 are controlled independently of each other. Because the two second coils 9 are controlled independently, when the magnetic suspension bearing works, if one second coil 9 fails, the two second coils 9 are opposite to each other, so that the other second coil 9 can still continuously realize the control function in the vertical direction, and the adjustment of the displacement of the rotor assembly 3 in the vertical direction can still be conveniently realized by controlling the current magnitude and direction in the other second coil 9, so that the fault tolerance is higher, and the stability and the reliability of the magnetic suspension bearing can be effectively improved.

Because first iron core 6 and second iron core 8 are radial setting, consequently the magnetic pole that first coil 7 of winding on first iron core 6 and second coil 9 of winding on second iron core 8 formed, also radial magnetic pole, through current size and the direction on adjusting first coil 7, can adjust the closed magnetic circuit magnetic force size of the first end of first permanent magnet 5, and then realize the displacement regulation on the horizontal direction of rotor subassembly 3. The magnetic force of the closed magnetic circuit at the second end of the first permanent magnet 5 can be adjusted by adjusting the current and the direction of the second coil 9, and then the displacement adjustment in the vertical direction of the rotor assembly 3 is realized.

Preferably, the first iron core 6 and the second iron core 8 are integrally formed with the stator iron core 4, so that the processing procedure of the first iron core can be reduced, the forming efficiency can be improved, and the processed magnetic suspension bearing has better magnetic performance.

In the present embodiment, the first permanent magnet 5 includes four ring segments that are evenly distributed circumferentially along the inner peripheral side of the stator core 4, two of the opposing ring segments being located on a first straight line, and the other two opposing ring segments being located on a second straight line. Specifically, four ring segments can be divided into two groups, and two ring segments of each group are located at two ends of the same diameter of the stator core, wherein two ring segments of the first group are circumferentially staggered with two first iron cores 6 and circumferentially located at the same circumferential position with the two first iron cores 6, and two ring segments of the second group are circumferentially staggered with two second iron cores 8 and circumferentially located at the same circumferential position with the two second iron cores 8. Thus, because the first straight line where the two first iron cores 6 are located is perpendicular to the second straight line where the two second iron cores 8 are located, the two ring-shaped sections of the first group and the two second iron cores 8 are staggered in the circumferential direction, the magnetic field generated by the two ring-shaped sections of the first group does not interfere with the magnetic field generated by the second coil 9 on the second iron core 8, and similarly, the magnetic field generated by the two ring-shaped sections of the second group does not interfere with the magnetic field generated by the first coil 7 on the first iron core 6, so that the coupling between the control magnetic circuits at the two ends can be more effectively avoided, the control complexity is further reduced, and the control accuracy is improved.

Preferably, the first permanent magnet 5 is located in the middle of the stator core 4, and the axial distances between the first control magnetic pole and the first permanent magnet 5 are the same as those between the second control magnetic pole and the first permanent magnet 5, so that the structural stability of the control magnetic poles at the two ends can be effectively ensured.

The first permanent magnet 5 may also be a permanent magnet ring structure. In this embodiment, the ring segment is a sector.

The fixed frame 10 is fixedly arranged on the inner peripheral wall of the stator core 4, the fixed frame 10 is provided with a fixed groove 11, and the first permanent magnet 5 is fixedly arranged in the fixed groove 11. Through increasing mount 10, can realize through mount 10 that first permanent magnet 5 is fixed in the installation on stator core 4, the structure is simpler, need not cause the destruction to first permanent magnet 5's structure, can make first permanent magnet 5's mounting structure more reliable and more stable moreover. The fixing frame 10 may be fixed to the inner circumferential wall of the stator core 4 by interference fit, gluing, or by two types of fitting, so as to achieve stable and reliable fixed connection, and the fixing frame 10 may also be fixed to the inner circumferential wall of the stator core 4 by other methods.

When first permanent magnet 5 is fan-shaped, fixed slot 11 also sets up to fan-shaped correspondingly, when installing, need first with fan-shaped permanent magnet from the opening part embedding of fixed slot 11 to the opening through the gradual shrink of fixed slot 11 forms radial spacing to the permanent magnet, makes the permanent magnet slide in fixed slot 11 and can not slide again behind the preset position. After the fan-shaped permanent magnet is installed in the fixed groove 11, the fixing frame 10 with the assembled permanent magnet can be integrally installed on the inner peripheral side of the stator core 4 and fixed, at the moment, the outer wall of the fan-shaped permanent magnet is pressed by the inner wall of the stator core 4, the side wall of the fan-shaped permanent magnet is pressed by the side wall of the fixed groove 11, and therefore the fan-shaped permanent magnet is stably and reliably limited in the fixed groove 11, and stable and reliable installation of the fan-shaped permanent magnet in the stator core 4 is achieved.

A stop ring 19 is also arranged in the stator core, and the fixing frame 10 is axially stopped on the stop ring 19. The stop ring 19 is disposed on the radially inner side of the stator core 4, may be integrally formed with the stator core 4, or may be separately machined and then fixedly disposed on the inner peripheral side of the stator core 4, and functions to position the axial installation position of the first permanent magnet 5 in the stator core 4. When the first permanent magnet 5 is fixedly installed, the first permanent magnet 5 can be installed on the inner peripheral side of the stator core 4 along the installation direction, when the first permanent magnet 5 reaches the axial position of the stop ring 19, the first permanent magnet 5 is stopped by the stop ring 19, the fact that the first permanent magnet 5 is installed in place is shown, the first permanent magnet 5 can be fixedly arranged at the current axial position, and accuracy and reliability of the axial installation position of the first permanent magnet 5 are guaranteed. Through setting up backstop ring 19, can reduce the installation degree of difficulty of first permanent magnet 5 in stator core 4, improve positioning accuracy, improve assembly efficiency. The stop ring 19 may be a stop block or other structure having a stopping function.

The stator core 4 includes an inner core 12 and control pole segments 13 located at two ends of the inner core 12, and at least one of the control pole segments 13 is separated from the inner core 12.

When first iron core 6 and second iron core 8 all with stator core 4 between the components of a whole that can function independently setting up, this moment when carrying out first permanent magnet 5's installation, can install first permanent magnet 5 in fixed slot 11 at first, then with mount 10 integral erection in stator core 4, and fix, accomplish fixed mounting back when first permanent magnet 5, can be respectively with the fixed first end that sets up at stator core 4 of first iron core 6, hold the fixed second that sets up at stator core 4 of second iron core 8, before this, can at first accomplish the coiling of first coil 7 on first iron core 6, and the coiling of second coil 9 on second iron core 8.

However, when the first iron core 6 and the second iron core 8 are integrally formed with the stator core 4, the first permanent magnet 5 is interfered in the installation of the stator core 4 due to the existence of the first iron core 6 and the second iron core 8, and the installation and fixation of the first permanent magnet 5 on the stator core 4 cannot be smoothly completed. At this moment, the stator core 4 needs to be designed again, and the stator core 4 is divided into a plurality of sections according to the installation positions of the first core 6, the second core 8 and the first permanent magnet 5, so that the first permanent magnet 5 can be fixedly installed on the stator core 4, and then the other stator cores 4 are combined together to form the complete stator core 4. In this embodiment, the stator core 4 is divided into the inner core 12 and the control pole sections 13 located at two ends of the inner core 12, both the two control pole sections 13 may be arranged separately from the inner core 12, or only one of the control pole sections 13 may be arranged separately from the inner core 12, so that the first permanent magnet 5 may be first installed into the inner core 12 from the end where the control pole section 13 is arranged separately, and finally the control pole section 13 is combined with the inner core 12, thereby smoothly completing the installation and fixation of the first permanent magnet 5.

Stator module 2 still includes casing 14, and casing 14 cover is established in stator core 4 periphery, and the both ends of casing 14 are provided with axial limit structure respectively, and stator core 4 passes through axial limit structure axial spacing in casing 14. The housing 14 is made of, for example, a non-magnetic material, and thus can form a shield from the outer peripheral side of the stator assembly 2, prevent magnetic lines of force from leaking from the outer peripheral side of the stator assembly 2, and improve the operational stability and reliability of the radial bearing. The axial limiting structure can axially limit the installation of the stator core 4 in the shell 14, and particularly, for the stator core 4 adopting a split structure, the axial limiting structure can effectively guarantee the matching effect between the stator cores 4 of all sections.

In the present embodiment, the axial limiting structure includes a stop flange 15 disposed at a first end of the housing 14 and an axial baffle 16 disposed at a second end of the housing 14, and the inner core 12 and the control pole segment 13 are both axially limited between the stop flange 15 and the axial baffle 16.

The stop flange 15 is formed integrally with the housing 14 and the axial stop 16 is removably fixedly attached to the second end of the housing 14. Because the stop flange 15 and the housing 14 are integrally formed, the number of machining processes can be reduced, the machining difficulty can be reduced, and the machining efficiency can be improved. And the axial baffle 16 is detachably and fixedly connected to the second end of the housing 14, so that the stator core 4 can be conveniently installed, detached and replaced in the housing 14.

The first control magnetic pole and the second control magnetic pole are independent of each other. The first control magnetic pole and the second control magnetic pole are independent from each other, namely the first control magnetic pole and the second control magnetic pole are independently controlled, and the operation and the stop of the first control magnetic pole are not mutually coherent with the operation and the stop of the second control magnetic pole, so that when one control magnetic pole fails, the normal work of the other control magnetic pole is not influenced, and the stability and the reliability of the magnetic suspension bearing during work are ensured.

The first permanent magnet 5 is connected with a fixed frame 10 by an interference fit or viscose method, a step is arranged in a fixed groove 11 of the fixed frame 10 to radially support the first permanent magnet 5, the fixed frame 10 is arranged in the middle of a stator iron core 4 by the interference fit, a stop ring 19 is arranged in the stator iron core 4 to axially position the fixed frame 10, each control winding is wound on the corresponding iron core by a winding way, two control magnetic pole sections 13 and one inner iron core 12 are arranged according to a preset sequence, then, the stator core 4 is fixedly connected in a high-pressure stamping and welding mode to form a stator core 4 which is complete in the radial direction, the stator core 4 is sleeved inside the shell 14 in a heating mode for the shell 14, the stator assembly is axially positioned through the axial baffle 16, the radial and axial fixing of the stator assembly is completed, and the fixed assembly of the permanent magnet offset radial bearing part is realized.

In the radial bearing 1, the sector permanent magnets are magnetized in the radial direction, the sector permanent magnets in the horizontal direction form a closed loop with the rotor assembly 3 through the first control magnetic poles for controlling horizontal displacement to generate a bias magnetic field in the horizontal direction, the sector permanent magnets in the vertical direction form a closed loop with the rotor assembly 3 through the second control magnetic poles for controlling vertical displacement to generate a bias magnetic field in the vertical direction, and the first coil 7 is wound on the magnetic poles of the first iron core 6 to generate a horizontal control magnetic field; the second coil 9 is wound around the poles of the second core 8 to generate a vertical control magnetic field.

The horizontal control magnetic circuit and the vertical control magnetic circuit are overlapped with the horizontal bias magnetic circuit and the vertical bias magnetic circuit only at the air gap formed by the radial magnetic pole and the rotor assembly 3, wherein the horizontal control magnetic circuit and the vertical control magnetic circuit are axially distributed on the stator iron core 4 and are not interfered with each other, and the horizontal bias magnetic circuit and the vertical bias magnetic circuit are respectively distributed on the horizontal plane and the vertical plane in the radial direction and are not interfered with each other.

Referring to fig. 10 to 13, the radial bearing works according to the following principle, taking the horizontal degree of freedom direction control as an example: a radial horizontal main air gap is formed between the horizontal control magnetic pole and the rotor assembly 3, the horizontal fan-shaped permanent magnet generates a horizontal bias magnetic field, the magnetic fluxes of the bias magnetic field in the left main air gap and the right main air gap in the radial horizontal plane are equal, and the radial direction horizontal degree of freedom of the rotor assembly 3 is stable. When the rotating shaft horizontally shifts to the left, the magnetic flux of the bias magnetic field in the left main air gap becomes large, the magnetic flux of the bias magnetic field in the right main air gap becomes small, and the radial horizontal degree of freedom of the rotor assembly 3 cannot be stabilized. At this time, the magnitude and direction of the control current can be changed by detecting the position of the rotating shaft through the sensor, and the control magnetic fields generated by the first control magnetic pole and the second control magnetic pole are mutually superposed to form a control magnetic circuit as shown in fig. 13, so that the magnetic flux in the horizontal left main air gap is reduced, the magnetic flux in the horizontal right main air gap is increased, the rotating shaft is translated towards the radial right end to reach a balance position, and the stable suspension of the rotating shaft in the horizontal direction is realized. 2 control windings in the horizontal direction are opposite to each other, one end breaks down, and the other end can continue to realize the control function in the horizontal direction, prevents that the pivot from appearing uncontrolled state. In the same way, the working principle in the vertical direction is the same, the control magnetic circuits in the vertical direction and the horizontal direction cannot be coupled, horizontal suction and vertical suction of different sizes can be provided according to requirements, system control is facilitated, and the stability and reliability of the magnetic suspension radial control system are improved.

Referring to fig. 4 to 6 and 14 in combination, according to an embodiment of the present application, a magnetic suspension bearing includes an axial bearing 17, where the axial bearing 17 includes an inner axial core 20, an outer axial core 21, a second permanent magnet 22, a first control winding 23 and a second control winding 24, the inner axial core 20 and the outer axial core 21 are coaxially disposed, the second permanent magnet 22 is disposed in a radial gap 25 between the inner axial core 20 and the outer axial core 21, the second permanent magnet 22 is radially magnetized, the first control winding 23 is wound in the radial gap 25 and located at a first end of the second permanent magnet 22, and the second control winding 24 is wound in the radial gap 25 and located at a second end of the second permanent magnet 22.

This magnetic suspension bearing's axial bearing is at the during operation, owing to adopted permanent magnetism biasing structure, consequently can provide the axial magnetic field effect of lasting stability through the permanent magnet, first control winding and second control winding are only used for controlling the balanced magnetic force size at magnetic suspension bearing axial direction both ends, even in the course of the work because the trouble leads to one of them control winding or two control windings all to break down, still can make magnetic suspension bearing effective work through the biasing magnetic field that the permanent magnet provided, avoid the magnetic suspension bearing to become invalid, avoid high-speed rotatory pivot emergence uncontrolled potential safety hazard, improve magnetic suspension system's stability and reliability.

The second permanent magnet 22 is a permanent magnet ring. The second permanent magnet 22 may also be a fan-shaped permanent magnet, or other similarly configured permanent magnet.

An insulating framework 26 is further arranged in the radial gap 25, and the first control winding 23 and the second control winding 24 are wound on the insulating framework 26. The effect of insulating skeleton 26 lies in, conveniently controls the winding of winding, also can design the magnetic circuit simultaneously, avoids the magnetic circuit to take place the short circuit, guarantees the rationality of magnetic circuit design, improves axial bearing 17's magnetic property. The two insulation frameworks 26 are respectively arranged at the two axial ends of the radial gap 25, the first control winding 23 is wound on the first section of insulation framework 26, the second control winding 24 is wound on the second section of insulation framework 26, and the two insulation frameworks 26 are spaced by the second permanent magnet 22.

In this embodiment, the insulating bobbin 26 cooperates with the second permanent magnet 22 to completely separate the inner axial core 20 and the outer axial core 21. Through cooperating with insulating skeleton 26 and second permanent magnet 22, can keep apart interior axial core 20 and outer axial core 21 completely, thereby make the bias magnetic field that the permanent-magnet ring produced and the control magnetic field that the control winding produced only can form complete closed circuit through the axial air gap at left and right both ends and thrust disc 18, thereby can guarantee that the bias magnetic field that the permanent-magnet ring produced and the control magnetic field that the control winding produced can not take place the short circuit, can produce sufficient axial effort, realize the regulation to the axial position of rotor subassembly 3, and then realize the regulation to the axial position of countershaft. Specifically, the insulating bobbin 26 at the first end of the inner axial bearing 20 extends from the first end of the inner axial bearing 20 to the first end face of the second permanent magnet 22, and the insulating bobbin 26 at the second end of the inner axial bearing 20 extends from the second end of the inner axial bearing 20 to the second end face of the second permanent magnet 22, thereby separating the inner axial core 20 and the outer axial core 21 in the entire axial direction.

The outer circumferential wall of the inner axial core 20 is provided with a first stopping protrusion 27, the inner circumferential wall of the outer axial core 21 is provided with a second stopping protrusion 28, the first end of the second permanent magnet 22 is stopped on the first stopping protrusion 27, and the second end of the second permanent magnet 22 is stopped on the second stopping protrusion 28. The outer circumferential wall of the inner axial iron core 20 is provided with the first stopping protrusion 27, the inner circumferential wall of the outer axial iron core 21 is provided with the second stopping protrusion 28, the mounting position of the second permanent magnet 22 on the inner axial iron core 20 can be axially positioned through the matching of the first stopping protrusion 27 and the second stopping protrusion 28, the mounting difficulty is reduced, meanwhile, the positioning of the axial relative position of the inner axial iron core 20 and the outer axial iron core 21 can be realized through the second permanent magnet 22, when the inner axial iron core 20 and the outer axial iron core 21 are designed, the axial positions of the first stopping protrusion 27 and the second stopping protrusion 28 can be reasonably designed only by determining the axial length of the second permanent magnet 22, when the mounting is carried out, as long as the axial position of the second permanent magnet 22 is limited through the first stopping protrusion 27 or the second stopping protrusion 28, so long as the two stopping protrusions are both mounted in place, the axial relative positions of the inner axial iron core 20 and the outer axial iron core 21 are also naturally determined, so that the assembly difficulty of the inner axial iron core 20 and the outer axial iron core 21 is reduced, and the assembly efficiency is improved. Meanwhile, because the two stopping protrusions are respectively positioned on different axial iron cores, the stopping protrusions and the axial iron cores where the stopping protrusions are positioned can be integrally manufactured, the manufacturing difficulty is reduced, the magnetic performance of the axial iron cores is improved, and the second permanent magnets 22 can be conveniently installed and fixed.

In other embodiments, both the stopping protrusions may be disposed on the same axial core, in which case one of the stopping protrusions needs to be detachably disposed on the axial core, or the stopping protrusion needs to be fixedly connected to the axial core after the second permanent magnet 22 is mounted on the axial core.

The first stop projection 27 and/or the second stop projection 28 are annular projections. The stop protrusion may be a plurality of stop blocks as long as the axial installation position of the second permanent magnet 22 can be accurately positioned.

In this embodiment, the radial heights of the first stopping protrusion 27 and the second stopping protrusion 28 are both smaller than the thickness of the annular gap, so that a gap with a certain thickness is formed between the first stopping protrusion 27 and the inner peripheral wall of the outer axial core 21, a gap with a certain thickness is also formed between the second stopping protrusion 28 and the outer peripheral wall of the inner axial core 20, the insulating skeleton 26 at the first end of the inner axial core 20 has an annular flange axially protruding toward the second permanent magnet 22, the annular flange is clamped in the gap formed between the first stopping protrusion 27 and the inner peripheral wall of the outer axial core 21, and the insulating skeleton 26 at the second end of the inner axial core 20 has an annular flange axially protruding toward the second permanent magnet 22, and the annular flange is clamped in the gap formed between the second stopping protrusion 28 and the outer peripheral wall of the inner axial core 20. Through the clearance that forms between protruding and the axial iron core of backstop, can conveniently install the location to insulating skeleton 26, simultaneously, also can separate first backstop arch 27 and outer axial iron core 21, separate second backstop arch 28 and interior axial iron core 20, form the short circuit through the protruding contact of backstop between avoiding interior axial iron core 20 and the outer axial iron core 21, guarantee more effectively that the bias magnetic field that the permanent magnetism ring produced and the control magnetic field that the control winding produced only can form complete closed circuit through the axial air gap and the thrust plate 18 at left and right both ends.

The first stop projection 27 may also be provided at the second end of the inner axial core 20, in which case the second stop projection 28 is provided at the first end of the outer axial core 21.

The axial bearing 17 is fixedly sleeved with a shell 29. Preferably, the housing 29 is made of a non-magnetic material, so that leakage of the axial bearing 17 from the outer shaft to the outer peripheral side of the core 21 can be effectively avoided, and the magnetic performance of the axial bearing 17 can be ensured.

Preferably, the first control winding 23 and the second control winding 24 are energized in the same direction.

Preferably, the first control winding 23 and the second control winding 24 are each independently controlled.

The magnetic suspension bearing further comprises a rotor assembly 3, two ends of the axial bearing 17 are respectively provided with a thrust disc 18, and the thrust discs 18 are fixedly arranged on the rotor assembly 3.

The permanent magnet ring of the axial bearing 17 is embedded in the outer axial iron core 21 in an interference fit or adhesive mode, the second stop protrusion 28 is arranged inside the outer axial iron core 21 to axially limit the permanent magnet ring, the inner axial iron core 20 is embedded in the inner ring of the permanent magnet ring in an interference and adhesive mode, the first stop protrusion 27 is arranged on the outer ring of the inner axial iron core 20 to axially limit the permanent magnet ring, and the inner axial iron core and the outer axial iron core fixedly support the radial direction and the axial direction of the permanent magnet ring. The control winding is wound around the insulating frame 26 and sealed with a sealant. The insulating frameworks 26 at the left end and the right end are embedded in grooves formed by the inner axial iron core and the outer axial iron core through interference fit or a viscose method, so that the insulating frameworks 26 are fixedly supported, and a complete biaxial bearing assembly is formed. The insulating framework 26 is matched with the permanent magnetic ring to completely isolate the inner axial iron core from the outer axial iron core, and a bias magnetic field generated by the permanent magnetic ring and a control magnetic field generated by the control winding can form a complete closed loop only through the axial air gaps at the left end and the right end and the thrust plate. The power-on directions of the control windings at the left end and the right end are the same, generated control magnetic fields are mutually overlapped to form a closed loop, the windings at the two ends control the magnetic force in the axial unilateral direction at the same time, the potential safety hazard of no control of a rotating shaft rotating at a high speed is avoided, and the stability and the reliability of the magnetic suspension system are improved. The axial freedom degree of the rotating shaft is controlled by matching the two control windings positioned at the two axial ends of the axial iron core with the two thrust discs 18, so that the integration of two axial bearings is realized, the part processing cost is reduced, the installation is convenient, the occupied space of a magnetic suspension axial supporting system is reduced, and the use mode of the axial magnetic bearing is increased.

The technical principle of the permanent magnet biased biaxial magnetic bearing is shown in fig. 14, a permanent magnet ring radially magnetizes an outer N inner S, a closed loop is formed by an outer axial iron core 21, a left axial air gap, a right axial air gap, a left thrust disc 18, a right thrust disc 18 and an inner axial iron core 20 respectively to form a biased magnetic circuit, static biased magnetic fluxes are established in the left axial air gap and the right axial air gap, when a rotating shaft is in a stable balance position, the biased magnetic fluxes in the left axial air gap and the right axial air gap are equal in magnitude, the attractive forces of the axial iron cores to the left thrust disc and the right thrust disc are equal in magnitude and opposite in direction, and the rotating shaft is. The left and right control windings are independently embedded at the axial magnetic pole formed by the outer axial iron core 21 and the inner axial iron core 20, and control magnetic circuits generated by the control windings at two ends are mutually overlapped to generate a control magnetic field and control the magnetic flux in the left and right air gaps. When the left control winding or the right control winding is in open circuit, the other control winding can also generate a control action, so that the rotating shaft is prevented from being in an uncontrolled state, and the stability and the reliability of the magnetic suspension axial control system are improved. The required bias magnetic field is formed by the permanent magnet, the number of turns of the electromagnetic coil is reduced, and the volume and the weight required by generating unit bearing capacity are reduced, so that the volume of the bearing is reduced.

The axial bearing adopts a working mode that the middle part is a bearing and the two ends are thrust disks, and the working state that the two ends are fixed, the middle part moves or the middle part is fixed and the two ends move is realized by using diversification; when the suspension is matched with a radial bearing for use, the suspension can be axially arranged and can also be radially arranged, and three-degree-of-freedom suspension is realized. The bearing has wider application range and wider application occasions. When the suspension device is arranged in the radial direction, the suspension device is applied to automobile suspension, train suspension and the like, a left wheel disc and a right wheel disc of an automobile and a left guide rail and a right guide rail of a train are equivalent to thrust discs, and a vehicle body is equivalent to a radial-axial integrated system, so that the vehicle body suspension is realized.

Referring to fig. 7 to 9, 15 and 16 in combination, according to an embodiment of the present application, the magnetic suspension bearing includes a radial bearing 1 and an axial bearing 17, and the axial bearing 17 is sleeved on the outer periphery of the radial bearing 1.

In this embodiment, the axial bearing 17 and the radial bearing 1 are radially arranged, so that integration of the magnetic suspension bearing can be realized, the axial utilization space of the magnetic suspension system and the axial length and production cost of the rotating shaft are reduced, the overall volume of the magnetic suspension bearing is reduced, the dynamic characteristic of the rotor is improved, and the installation and performance debugging of the bearing are facilitated.

In the embodiment, the radial bearing and the axial bearing are integrated, two degrees of freedom of the rotor which are mutually vertical in the radial direction and the axial degree of freedom of the rotating shaft can be controlled, and three-degree-of-freedom magnetic suspension control is conveniently realized.

Preferably, both ends of the axial bearing 17 are flush with both ends of the radial bearing 1, so that the radial bearing 1 and the axial bearing 17 can be more reasonably arranged, the length of the rotating shaft is further reduced, and the axial length and the volume of the magnetic suspension bearing are reduced.

In another embodiment, the magnetic suspension bearing comprises two radial bearings 1 arranged at intervals along the axial direction, and the axial bearing 17 is sleeved on the periphery of one of the radial bearings 1. In this embodiment, the independent radial bearing 1 is disposed at the first end of the rotating shaft, the integrated structure of the axial bearing 17 and the radial bearing 1 is disposed at the second end of the rotating shaft, the radial bearing 1 disposed at the first end of the rotating shaft can control two degrees of freedom of the first end of the rotating shaft in the radial direction, the integrated structure of the axial bearing 17 and the radial bearing 1 can control two degrees of freedom of the second end of the rotating shaft in the radial direction and the axial degree of freedom of the rotating shaft, so as to realize five-degree-of-freedom suspension control of the rotating shaft.

The radial bearing and the axial bearing are radially integrated as shown in fig. 7, and the integrated system can control two radial degrees of freedom and two axial degrees of freedom of the rotating shaft. The radial bearing assembly is embedded within the housing 14 by heating the housing 14. The axial bearing is embedded in the housing 29 by means of heating the housing 29. The inner ring of the axial iron core 20 in the axial bearing is sleeved in the shell 14, and the radial integration of the radial bearing and the axial bearing is realized by axially fixing (such as interference fit or bolt connection) in a certain connection mode, so that the axial utilization space of a magnetic suspension system and the axial length and production cost of a rotating shaft are reduced, the dynamic characteristic of a rotor is improved, and the installation and performance debugging of the bearing are facilitated.

Because the shell 14 is supported by non-magnetic-conductive materials, the interference of the magnetic circuits of the axial bearing 17 and the radial bearing 1 can be effectively avoided, the control program is simplified, the control precision and the control efficiency are improved, and the control cost is reduced.

According to an embodiment of the application, the motor comprises a magnetic bearing, which is the magnetic bearing described above.

According to an embodiment of the present application, the compressor comprises a magnetic bearing, which is the above-mentioned magnetic bearing.

According to an embodiment of the present application, the air conditioner includes a magnetic bearing, which is the above-mentioned magnetic bearing.

It is readily understood by a person skilled in the art that the advantageous ways described above can be freely combined, superimposed without conflict.

The present invention is not intended to be limited to the particular embodiments shown and described, but is to be accorded the widest scope consistent with the principles and novel features herein disclosed. The foregoing is only a preferred embodiment of the present application, 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 application, and these modifications and variations should also be considered as the protection scope of the present application.

Claims

1. Magnetic bearing, characterized in that it comprises an axial bearing (17), said axial bearing (17) comprising an inner axial core (20), an outer axial core (21), a second permanent magnet (22), a first control winding (23) and a second control winding (24), the inner axial core (20) and the outer axial core (21) being arranged coaxially, the second permanent magnet (22) being arranged in a radial gap (25) between the inner axial core (20) and the outer axial core (21), the second permanent magnet (22) is magnetized in the radial direction, the first control winding (23) is wound in the radial gap (25), and is located at a first end of the second permanent magnet (22), and the second control winding (24) is wound in the radial gap (25) and is located at a second end of the second permanent magnet (22).

2. Magnetic suspension bearing according to claim 1, characterized in that the second permanent magnet (22) is a permanent magnet ring.

3. Magnetic suspension bearing according to claim 1, characterized in that an insulating skeleton (26) is further arranged in the radial gap (25), and the first control winding (23) and the second control winding (24) are wound on the insulating skeleton (26).

4. Magnetic suspension bearing according to claim 3, characterized in that the insulating skeleton (26) cooperates with the second permanent magnet (22) to completely separate the inner axial core (20) from the outer axial core (21).

5. Magnetic bearing according to claim 1, characterized in that a first stop protrusion (27) is provided on the outer circumferential wall of the inner axial core (20), a second stop protrusion (28) is provided on the inner circumferential wall of the outer axial core (21), a first end of the second permanent magnet (22) stops on the first stop protrusion (27), and a second end of the second permanent magnet (22) stops on the second stop protrusion (28).

6. Magnetic bearing according to claim 5, characterized in that the first stop projection (27) and/or the second stop projection (28) is an annular projection.

7. Magnetic bearing according to claim 1, characterized in that the axial bearing (17) is fitted with a housing (29) on the outside.

8. Magnetic bearing according to claim 1, characterized in that the first control winding (23) and the second control winding (24) are energized in the same direction.

9. Magnetic bearing according to claim 1, characterized in that the first control winding (23) and the second control winding (24) are each controlled independently.

10. The magnetic suspension bearing according to claim 1, characterized in that the magnetic suspension bearing further comprises a rotor assembly (3), the two ends of the axial bearing (17) are respectively provided with a thrust disc (18), and the thrust discs (18) are fixedly arranged on the rotor assembly (3).

11. Magnetic bearing according to any of claims 1 to 10, characterized in that the magnetic bearing further comprises a radial bearing (1), the radial bearing (1) being fitted on the inner circumferential side of the inner axial core (20).

12. The magnetic suspension bearing according to claim 11, wherein the radial bearing (1) comprises a stator assembly (2) and a rotor assembly (3), the stator assembly (2) comprises a stator core (4), the rotor assembly (3) is sleeved on the inner peripheral side of the stator assembly (2), a first permanent magnet (5) for generating a bias magnetic field is arranged in the middle of the stator core (4) in the axial direction, the first permanent magnet (5) is magnetized in the radial direction, a first control magnetic pole is arranged at a first end of the inner peripheral wall of the stator core (4) and used for controlling the rotor assembly (3) to reciprocate along a first straight line, a second control magnetic pole is arranged at a second end of the inner peripheral wall of the stator core (4) and used for controlling the rotor assembly (3) to reciprocate along a second straight line, the first line is located in a first plane, the second line is located in a second plane, the first plane and the second plane are different planes, and the first plane and the second plane are perpendicular to the central axis of the stator core (4).

13. Magnetic bearing according to claim 12, characterized in that the first permanent magnet (5), the stator core (4), the first control magnetic pole and the rotor assembly (3) form therebetween a first control magnetic field for controlling the rotor assembly (3) to reciprocate along a first straight line, the first control magnetic field being located at a first end of the first permanent magnet (5); the first permanent magnet (5), the stator core (4), the second control magnetic pole and the rotor assembly (3) form a second control magnetic field for controlling the rotor assembly (3) to reciprocate along a second straight line, and the second control magnetic field is located at the second end of the first permanent magnet (5).

14. Magnetic bearing according to claim 12, characterized in that the first control magnetic pole comprises a first core (6) arranged at the first end of the stator core (4) and a first coil (7) wound around the first core (6), two first cores (6) are located at two ends of the same diameter of the stator core (4), and the first cores (6) protrude from the inner circumferential wall of the stator core (4) radially towards the central axis of the stator core (4); and/or, the second control magnetic pole is including setting up second iron core (8) of stator core (4) second end tip and around establishing second coil (9) on second iron core (8), two second iron core (8) are located the both ends of the same diameter of stator core (4), second iron core (8) are followed the internal perisporium of stator core (4) is radial to the central axis protrusion of stator core (4).

15. Magnetic bearing according to claim 12, characterized in that the first permanent magnet (5) comprises four ring segments, which are evenly distributed circumferentially along the inner circumference of the stator core (4), wherein two opposite ring segments are located on a first straight line and the other two opposite ring segments are located on a second straight line.

16. Magnetic bearing according to claim 12, characterized in that the stator core (4) comprises an inner core (12) and control pole segments (13) at both ends of the inner core (12), at least one of the control pole segments (13) being arranged separately from the inner core (12).

17. The magnetic suspension bearing according to claim 16, wherein the stator assembly (2) further comprises a housing (14), the housing (14) is sleeved on the periphery of the stator core (4), two ends of the housing (14) are respectively provided with an axial limiting structure, and the stator core (4) is axially limited in the housing (14) through the axial limiting structure.

18. Magnetic bearing according to claim 17, characterized in that the housing (14) is sheathed in and fixed to the inner ring of the inner axial core (20).

19. An electric machine comprising a magnetic bearing, characterized in that the magnetic bearing is a magnetic bearing according to any one of claims 1 to 18.

20. A compressor comprising magnetic bearings, characterized in that the magnetic bearings are magnetic bearings according to any one of claims 1 to 18.

21. An air conditioner comprising a magnetic bearing, wherein the magnetic bearing is the magnetic bearing of any one of claims 1 to 18.