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

Abstract

The present invention provides a magnetic levitation active three-degree-of-freedom bearing and a compressor. The magnetic levitation active three-degree-of-freedom bearing includes: an axial magnetic bearing, a radial magnetic bearing, and a bearing rotor. The axial magnetic bearing includes a first axial stator and a second axial stator. The radial magnetic bearing includes a radial stator. The radial stator is located on the outer periphery of the bearing rotor and can apply a radial electromagnetic force to the bearing rotor. The first axial stator and the second axial stator can apply an axial electromagnetic force to the bearing rotor. The bias magnetic flux of the radial magnetic bearing is provided by the axial magnetic bearing. Both the first axial stator and the second axial stator are segmented structures arranged at intervals in the circumferential direction. The number of pole columns of the radial stator is 12, that is, a radial 12-pole stator is formed. According to the present invention, the first and second axial stators can effectively provide a bias magnetic path for the radial stator, eliminating the original structures such as the bias stator, etc. The structure is more compact and simple, the process difficulty is reduced, the volume is reduced, and the assembly is easy.

Description

Technical Field

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

[0002] The magnetic levitation bearing suspends the rotating shaft by the electromagnetic force on the rotor, and the rotating shaft and the stator remain in a non-contact state, so it has the advantages of no wear, high speed, high precision, long life, etc. Magnetic bearings can be classified into three categories according to the working principle: active magnetic bearings, passive magnetic bearings and hybrid magnetic bearings.

[0003] The structure of the active three-degree-of-freedom magnetic bearing in the patent No. CN110017330A "An Axial-Radial Electromagnetic Magnetic Bearing" is complex. It uses an E-shaped salient pole radial segmented stator to form the bias magnetic flux for the radial bearing. Its processing and manufacturing process is complex, the assembly is difficult, and there is magnetic flux leakage in the axial direction of the radial suspension winding.

[0004] Due to the technical problems such as complex structure, large volume, complex process and difficult assembly caused by the existing magnetic levitation active three-degree-of-freedom bearing forming the bias magnetic flux of the radial bearing by setting a bias stator, the present invention researches and designs a magnetic levitation active three-degree-of-freedom bearing, a motor and a compressor. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defects of complex structure and large volume caused by the existing magnetic levitation active three-degree-of-freedom bearing forming the bias magnetic flux of the radial bearing by setting a bias stator, so as to provide a magnetic levitation active three-degree-of-freedom bearing, a motor and a compressor.

[0006] To solve the above problems, the present invention provides a magnetic levitation active three-degree-of-freedom bearing, which includes:

[0007] Axial magnetic bearings, radial magnetic bearings, and a bearing rotor. The axial magnetic bearings and the radial magnetic bearings are both sleeved on the outer periphery of a rotating shaft. The axial magnetic bearings include a first axial stator and a second axial stator. The radial magnetic bearings include a radial stator. The bearing rotor is sleeved on the outer periphery of the rotating shaft and can rotate together with the rotating shaft. The radial stator is located on the outer periphery of the bearing rotor and can apply a radial electromagnetic force to the bearing rotor. Along the axial direction of the rotating shaft, at least part of the structure of the first axial stator is located at one axial end of the bearing rotor, and at least part of the structure of the second axial stator is located at the other axial end of the bearing rotor. The first axial stator and the second axial stator can apply an axial electromagnetic force to the bearing rotor, and at least part of the structure of the first axial stator is located on the radial outer side of the bearing rotor, and at least part of the structure of the second axial stator is located on the radial outer side of the bearing rotor, so that the bias magnetic flux of the radial magnetic bearing is provided by the axial magnetic bearing. The first axial stator and the second axial stator are both segmented structures arranged at intervals in the circumferential direction;

[0008] The radial stator includes a radial iron core and a radial winding. The radial iron core is of an annular structure and is sleeved on the radial outer side of the bearing rotor; the radial iron core includes a radial stator yoke and radial stator pole columns. The radial stator yoke is of an annular structure. The radially outer ends of the radial stator pole columns are connected to the radial stator yoke, and the radially inner ends protrude towards the bearing rotor and have a radial working gap with the bearing rotor. The radial winding is wound around each radial stator pole column; the number of the radial stator pole columns is 12, that is, a radial 12-pole stator is formed.

[0009] In some embodiments, the structures of the first axial stator and the second axial stator are the same, and both include a first axial stator unit, a second axial stator unit, a third axial stator unit, a fourth axial stator unit, a fifth axial stator unit, a sixth axial stator unit, a seventh axial stator unit, and an eighth axial stator unit that are sequentially arranged at intervals in the circumferential direction.

[0010] In some embodiments, in the radial cross-section, the radial stator includes a first quadrant part located in the upper right, a second quadrant part located in the upper left, a third quadrant part located in the lower left, and a fourth quadrant part located in the lower right. The first quadrant part, the second quadrant part, the third quadrant part, and the fourth quadrant part are sequentially connected counterclockwise. The first quadrant part and the third quadrant part form a diagonal, and the second quadrant part and the fourth quadrant part form a diagonal.

[0011] In some embodiments, the radial stator pole column includes a second radial magnetic pole, a third radial magnetic pole, and a fourth radial magnetic pole located in the first quadrant portion. The radial stator pole column further includes a fifth radial magnetic pole, a sixth radial magnetic pole, and a seventh radial magnetic pole located in the fourth quadrant portion. The radial stator pole column further includes an eighth radial magnetic pole, a ninth radial magnetic pole, and a tenth radial magnetic pole located in the third quadrant portion. The radial stator pole column further includes an eleventh radial magnetic pole, a twelfth radial magnetic pole, and a first radial magnetic pole located in the second quadrant portion.

[0012] In some embodiments, along the circumferential direction of the radial stator, the third radial magnetic pole is located between the second radial magnetic pole and the fourth radial magnetic pole, and the circumferential width of the third radial magnetic pole is greater than the circumferential widths of the second radial magnetic pole and the fourth radial magnetic pole respectively. The circumferential widths of the second radial magnetic pole and the fourth radial magnetic pole are equal.

[0013] Along the circumferential direction of the radial stator, the sixth radial magnetic pole is located between the fifth radial magnetic pole and the seventh radial magnetic pole, and the circumferential width of the sixth radial magnetic pole is greater than the circumferential widths of the fifth radial magnetic pole and the seventh radial magnetic pole respectively. The circumferential widths of the fifth radial magnetic pole and the seventh radial magnetic pole are equal.

[0014] Along the circumferential direction of the radial stator, the ninth radial magnetic pole is located between the eighth radial magnetic pole and the tenth radial magnetic pole, and the circumferential width of the ninth radial magnetic pole is greater than the circumferential widths of the eighth radial magnetic pole and the tenth radial magnetic pole respectively. The circumferential widths of the eighth radial magnetic pole and the tenth radial magnetic pole are equal.

[0015] Along the circumferential direction of the radial stator, the twelfth radial magnetic pole is located between the eleventh radial magnetic pole and the first radial magnetic pole, and the circumferential width of the twelfth radial magnetic pole is greater than the circumferential widths of the eleventh radial magnetic pole and the first radial magnetic pole respectively. The circumferential widths of the eleventh radial magnetic pole and the first radial magnetic pole are equal.

[0016] In some embodiments, the magnetic paths inside the first radial magnetic pole, the bearing rotor, the twelfth radial magnetic pole, and the radial stator yoke are connected to form a closed loop, forming a radial bearing magnetic path; the magnetic paths inside the second radial magnetic pole, the bearing rotor, the third radial magnetic pole, and the radial stator yoke are also connected to form a closed-loop radial bearing magnetic path; the magnetic paths inside the third radial magnetic pole, the bearing rotor, the fourth radial magnetic pole, and the radial stator yoke are also connected to form a closed-loop radial bearing magnetic path; the magnetic paths inside the fifth radial magnetic pole, the bearing rotor, the sixth radial magnetic pole, and the radial stator yoke are also connected to form a closed-loop radial bearing magnetic path; the magnetic paths inside the sixth radial magnetic pole, the bearing rotor, the seventh radial magnetic pole, and the radial stator yoke are also connected to form a closed-loop radial bearing magnetic path; the magnetic paths inside the eighth radial magnetic pole, the bearing rotor, the ninth radial magnetic pole, and the radial stator yoke are also connected to form a closed-loop radial bearing magnetic path; the magnetic paths inside the ninth radial magnetic pole, the bearing rotor, the tenth radial magnetic pole, and the radial stator yoke are also connected to form a closed-loop radial bearing magnetic path; the magnetic paths inside the eleventh radial magnetic pole, the bearing rotor, the twelfth radial magnetic pole, and the radial stator yoke are also connected to form a closed-loop radial bearing magnetic path.

[0017] In some embodiments, the first axial stator unit is opposite to the first radial magnetic pole in the second quadrant part and the second radial magnetic pole in the first quadrant part, and provides a bias magnetic path for the first radial magnetic pole and the second radial magnetic pole through the first axial stator unit; the second axial stator unit is opposite to the third radial magnetic pole in the first quadrant part, and provides a bias magnetic path for the third radial magnetic pole through the second axial stator unit;

[0018] The third axial stator unit is opposite to the fourth radial magnetic pole in the first quadrant part and the fifth radial magnetic pole in the fourth quadrant part, and provides a bias magnetic path for the fourth radial magnetic pole and the fifth radial magnetic pole through the third axial stator unit; the fourth axial stator unit is opposite to the sixth radial magnetic pole in the fourth quadrant part, and provides a bias magnetic path for the sixth radial magnetic pole through the fourth axial stator unit;

[0019] The fifth axial stator unit is opposite to the seventh radial magnetic pole in the fourth quadrant part and the eighth radial magnetic pole in the third quadrant part, and provides a bias magnetic path for the seventh radial magnetic pole and the eighth radial magnetic pole through the fifth axial stator unit; the sixth axial stator unit is opposite to the ninth radial magnetic pole in the third quadrant part, and provides a bias magnetic path for the ninth radial magnetic pole through the sixth axial stator unit;

[0020] The seventh axial stator unit faces the tenth radial magnetic pole in the third quadrant part and the eleventh radial magnetic pole in the second quadrant part, and provides a bias magnetic circuit for the tenth radial magnetic pole and the eleventh radial magnetic pole through the seventh axial stator unit; the eighth axial stator unit faces the twelfth radial magnetic pole in the second quadrant part, and provides a bias magnetic circuit for the twelfth radial magnetic pole through the eighth axial stator unit.

[0021] In some embodiments, the bias magnetic circuits provided by the first axial stator unit for the first radial magnetic pole and the second radial magnetic pole both face the center of the rotation axis in the radial direction; the bias magnetic circuit provided by the second axial stator unit for the third radial magnetic pole faces away from the center of the rotation axis in the radial direction; the bias magnetic circuits provided by the third axial stator unit for the fourth radial magnetic pole and the fifth radial magnetic pole both face the center of the rotation axis in the radial direction; the bias magnetic circuit provided by the fourth axial stator unit for the sixth radial magnetic pole faces away from the center of the rotation axis in the radial direction;

[0022] The bias magnetic circuits provided by the fifth axial stator unit for the seventh radial magnetic pole and the eighth radial magnetic pole both face the center of the rotation axis in the radial direction; the bias magnetic circuit provided by the sixth axial stator unit for the ninth radial magnetic pole faces away from the center of the rotation axis in the radial direction; the bias magnetic circuits provided by the seventh axial stator unit for the tenth radial magnetic pole and the eleventh radial magnetic pole both face the center of the rotation axis in the radial direction; the bias magnetic circuit provided by the eighth axial stator unit for the twelfth radial magnetic pole faces the center of the rotation axis in the radial direction.

[0023] In some embodiments, the first axial stator includes a first axial iron core and a first axial winding. The first axial iron core is of an annular structure and includes a first main body part, a first annular part and a second annular part. The first main body part is of a disc structure with a first central hole, and the first central hole accommodates the rotation axis to pass through. The second annular part is located radially outside the first annular part. One end of the first annular part is connected to the first main body part and the other end extends towards the bearing rotor to face the bearing rotor. One end of the second annular part is connected to the first main body part and the other end extends towards the radial iron core to face the radial iron core, so as to form a first accommodation groove between the radially outer side of the first annular part and the radially inner side of the second annular part, and the first axial winding is wound on the second annular part.

[0024] In some embodiments, the first annular portion extends along the axial direction of the rotating shaft and is spaced from the bearing rotor by a third preset distance to form a first axial working clearance; the second annular portion also extends along the axial direction of the rotating shaft and is spaced from the radial iron core by a fourth preset distance to form a second axial working clearance.

[0025] In some embodiments, the second axial stator includes a second axial iron core and a second axial winding. The second axial iron core is of an annular structure and includes a second main body portion, a third annular portion, and a fourth annular portion. The second main body portion is a disc structure having a second central hole, and the second central hole accommodates the rotating shaft passing therethrough. One end of the third annular portion is connected to the second main body portion and the other end extends toward the bearing rotor to be opposite to the bearing rotor. One end of the fourth annular portion is connected to the second main body portion and the other end extends toward the radial iron core to be opposite to the radial iron core, and the fourth annular portion is located radially outside the third annular portion to form a second accommodating groove between the radially outer side of the third annular portion and the radially inner side of the fourth annular portion, and the second axial winding is wound around the fourth annular portion.

[0026] In some embodiments, the third annular portion extends along the axial direction of the rotating shaft and is spaced from the bearing rotor by a fifth preset distance to form a first axial working clearance; the fourth annular portion also extends along the axial direction of the rotating shaft and is spaced from the radial iron core by a sixth preset distance to form a second axial working clearance.

[0027] In some embodiments, the energization directions of the first axial winding and the second axial winding are opposite; the radial winding is simultaneously located radially outside the second annular portion and the fourth annular portion, and both the second annular portion and the fourth annular portion are opposite to the radial stator poles.

[0028] The present invention also provides a motor, which includes the magnetic levitation active three-degree-of-freedom bearing described in any one of the preceding items.

[0029] The present invention also provides a compressor, which includes the magnetic levitation active three-degree-of-freedom bearing described in any one of the preceding items.

[0030] A magnetic levitation active three-degree-of-freedom bearing, a motor, and a compressor provided by the present invention have the following beneficial effects:

[0031] 1. By the effective arrangement of the axial magnetic bearing and the radial magnetic bearing, the radial stator is located on the outer periphery of the bearing rotor and can apply a radial electromagnetic force to the bearing rotor. At least part of the structure of the first axial stator is located at one axial end of the bearing rotor, and at least part of the structure of the second axial stator is located at the other axial end of the bearing rotor. The axial electromagnetic force can be applied to the bearing rotor through the first axial stator and the second axial stator, so that the bearing rotor can be applied a radial electromagnetic force by the radial stator to adjust the radial offset of the rotating shaft. At the same time, the bearing rotor can be applied an axial electromagnetic force by the first and second axial stators to adjust the axial offset of the rotating shaft. Finally, the purpose of realizing radial and axial support for the rotating shaft is achieved. The bias magnetic flux of the radial magnetic bearing is provided by the axial magnetic bearing. Compared with the existing active three-degree-of-freedom magnetic levitation bearing that needs to set structures such as bias stators to provide a bias magnetic path for the radial bearing, through the above structure setting of the present invention, the first and second axial stators can effectively provide a bias magnetic path for the radial stator, eliminating the original structures such as bias stators. The structure is more compact and simple, the process difficulty is reduced, the volume is reduced, and the assembly is easy; the present invention effectively combines the radial magnetic bearing and the axial magnetic bearing together to form an integrated axial-radial magnetic bearing structure. Compared with the existing separate axial magnetic bearing and radial magnetic bearing in the prior art that need to separately set a thrust bearing for the axial magnetic bearing to provide an axial force for the rotating shaft and need to set a radial magnetic bearing rotor for the radial magnetic bearing, the structure of the thrust bearing is effectively eliminated, the axial dimension of the rotor is effectively reduced and shortened, the radial bearing and the axial bearing are integrated, there is no thrust disk, the structure is compact, the bearing size is reduced, the rotor length is shortened, the critical speed of the rotor is increased, and the stability and applicability of the magnetic levitation system are improved; by providing a bias magnetic path for the radial stator through the axial stator, the present invention can effectively eliminate the structure of the permanent magnet compared with the hybrid magnetic levitation bearing, with low cost, convenient assembly, large bearing capacity, and can operate at high power; by making the axial stator poles into a segmented structure, the present invention can effectively reduce and avoid the magnetic leakage phenomenon of the radial magnetic path on the outer circle of the axial stator, thereby effectively enhancing the air-gap magnetic field on the radial poles, improving the control magnetic flux, increasing the radial output force, and improving the control performance.

[0032] 2. By arranging the radial windings on the radial outer sides of the first axial iron core and the second axial iron core, and both the second annular part and the fourth annular part are opposite to the radial stator pole columns, compared with the existing scheme where the upper magnetic pole of the axial stator is located beside the radial stator yoke (that is, the upper magnetic pole of the existing axial stator is located on one axial side of the radial stator yoke), the magnetic leakage of the radial magnetic path in the axial direction can be effectively reduced, and the situation of uneven axial output force in the circumferential direction can be effectively eliminated. Description of the Drawings

[0033] Figure 1It is the exploded view structure diagram of the magnetic levitation active three-degree-of-freedom bearing of the present invention;

[0034] Figure 2 It is the cross-sectional view structure diagram of the magnetic levitation active three-degree-of-freedom bearing of the present invention (radial section, radial magnetic circuit of the three-degree-of-freedom bearing);

[0035] Figure 3 It is the longitudinal section view structure diagram of the magnetic levitation active three-degree-of-freedom bearing of the present invention ( Figure 2 A-A sectional view axial section, axial magnetic circuit of the three-degree-of-freedom bearing);

[0036] Figure 4 It is Figure 3 The mating structure diagram of the axial stator, radial stator and bearing rotor of the upper half in the above;

[0037] Figure 5 It is the longitudinal section view structure diagram of the magnetic levitation active three-degree-of-freedom bearing of the present invention ( Figure 2 B-B sectional view axial section, axial magnetic circuit of the three-degree-of-freedom bearing);

[0038] Figure 6 It is the cross-sectional view schematic diagram of the axial stator of the magnetic levitation active three-degree-of-freedom bearing of the present invention.

[0039] The reference numerals are shown as:

[0040] 100, Axial magnetic bearing; 300, First axial stator; 1, Radial stator yoke; 2, Rotating shaft; 3, Radial bearing magnetic circuit; 31, Upper radial bearing magnetic circuit at section A; 32, Lower radial bearing magnetic circuit at section A; 4, Axial bearing magnetic circuit; 41, Upper axial bearing magnetic circuit at section A; 42, Lower axial bearing magnetic circuit at section A; 43, Upper axial bearing magnetic circuit at section B; 44, Lower axial bearing magnetic circuit at section B; 6, First axial iron core; 6a, First main body part; 6b, First annular part; 6c, Second annular part; 6d, First receiving groove; 61, First axial stator unit; 62, Second axial stator unit; 63, Third axial stator unit; 64, Fourth axial stator unit; 65, Fifth axial stator unit; 66, Sixth axial stator unit; 67, Seventh axial stator unit; 68, Eighth axial stator unit; 7, First axial winding; 400, Second axial stator; 11, Second axial iron core; 11a, Second main body part; 11b, Third annular part; 11c, Fourth annular part; 11d, Second receiving groove; 12, Second axial winding; 200, Radial magnetic bearing; 500, Radial stator; 5, Radial winding; 9, Bearing rotor; 10, Radial iron core; 8, Radial stator pole; 81, First radial magnetic pole; 82, Second radial magnetic pole; 83, Third radial magnetic pole; 84, Fourth radial magnetic pole; 85, Fifth radial magnetic pole; 86, Sixth radial magnetic pole; 87, Seventh radial magnetic pole; 88, Eighth radial magnetic pole; 89, Ninth radial magnetic pole; 810, Tenth radial magnetic pole; 811, Eleventh radial magnetic pole; 812, Twelfth radial magnetic pole; 15, Radial working clearance; 16, First axial working clearance; 19, Second axial working clearance. Detailed implementation manner

[0041] As Figures 1-6 shown, the present invention provides a magnetic levitation active three-degree-of-freedom bearing, which includes:

[0042] Axial magnetic bearing 100, radial magnetic bearing 200, and bearing rotor 9. Both the axial magnetic bearing 100 and the radial magnetic bearing 200 are sleeved on the outer periphery of the rotating shaft 2. The axial magnetic bearing 100 includes a first axial stator 300 and a second axial stator 400. The radial magnetic bearing 200 includes a radial stator 500. The bearing rotor 9 is sleeved on the outer periphery of the rotating shaft 2 and can rotate together with the rotating shaft 2. The radial stator 500 is located on the outer periphery of the bearing rotor 9 and can apply a radial electromagnetic force to the bearing rotor 9. Along the axial direction of the rotating shaft 2, at least part of the structure of the first axial stator 300 is located at one axial end of the bearing rotor 9, and at least part of the structure of the second axial stator 400 is located at the other axial end of the bearing rotor 9. The first axial stator 300 and the second axial stator 400 can apply an axial electromagnetic force to the bearing rotor 9, so that the bias magnetic flux of the radial magnetic bearing 200 is provided by the axial magnetic bearing 100. Both the first axial stator 300 and the second axial stator 400 are block structures arranged at intervals in the circumferential direction;

[0043] The radial stator 500 includes a radial iron core 10 and a radial winding 5. The radial iron core 10 is of an annular structure and is sleeved on the radial outer side of the bearing rotor 9. The radial iron core 10 includes a radial stator yoke 1 and radial stator pole columns 8. The radial stator yoke 1 is of an annular structure. The radially outer ends of the radial stator pole columns are connected to the radial stator yoke 1, and the radially inner ends protrude towards the bearing rotor 9 and have a radial working gap 15 with the bearing rotor 9. The radial winding 5 is wound around each radial stator pole column. The number of the radial stator pole columns is 12, that is, a radial 12-pole stator is formed.

[0044] Through the effective arrangement of the axial magnetic bearing and the radial magnetic bearing, the radial stator is located on the outer periphery of the bearing rotor and can apply a radial electromagnetic force to the bearing rotor. At least part of the structure of the first axial stator is located at one axial end of the bearing rotor, and at least part of the structure of the second axial stator is located at the other axial end of the bearing rotor, so that the axial electromagnetic force can be applied to the bearing rotor through the first axial stator and the second axial stator. As a result, the bearing rotor can be subjected to the radial electromagnetic force applied by the radial stator to adjust the radial offset of the rotating shaft, and at the same time, the bearing rotor can be subjected to the axial electromagnetic force applied by the first and second axial stators to adjust the axial offset of the rotating shaft. Finally, the purpose of realizing radial and axial support for the rotating shaft is achieved, and the bias magnetic flux of the radial magnetic bearing is provided by the axial magnetic bearing. Compared with the existing active three-degree-of-freedom magnetic levitation bearing that needs to set structures such as bias stators to provide a bias magnetic path for the radial bearing, through the above structure setting, the first and second axial stators of the present invention can effectively provide a bias magnetic path for the radial stator, eliminating the original structures such as bias stators. The structure is more compact and simple, the process difficulty is reduced, the volume is reduced, and the assembly is easy; the present invention effectively combines the radial magnetic bearing and the axial magnetic bearing together to form an integrated axial and radial magnetic bearing structure. Compared with the existing separate axial magnetic bearing and radial magnetic bearing in the prior art that need to separately set a thrust bearing for the axial magnetic bearing to provide an axial force for the rotating shaft and need to set a radial magnetic bearing rotor for the radial magnetic bearing, the structure of the thrust bearing is effectively eliminated, the axial dimension of the rotor is effectively reduced and shortened, the radial bearing and the axial bearing are integrated, there is no thrust disc, the structure is compact, the bearing size is reduced, the rotor length is shortened, the critical speed of the rotor is increased, and the stability and applicability of the magnetic levitation system are improved; by providing a bias magnetic path for the radial stator through the axial stator, the present invention can effectively eliminate the structure of the permanent magnet compared with the hybrid magnetic levitation bearing, with low cost, convenient assembly, large bearing capacity, and can operate at high power; by making the axial stator poles into a segmented structure, the present invention can effectively reduce and avoid the magnetic leakage phenomenon of the radial magnetic path on the outer circle of the axial stator, thereby effectively enhancing the air-gap magnetic field on the radial poles, improving the control magnetic flux, increasing the radial output force, and improving the control performance.

[0045] In some embodiments, the first axial stator 300 and the second axial stator 400 have the same structure, and both include a first axial stator unit 61, a second axial stator unit 62, a third axial stator unit 63, a fourth axial stator unit 64, a fifth axial stator unit 65, a sixth axial stator unit 66, a seventh axial stator unit 67, and an eighth axial stator unit 68 that are sequentially arranged at intervals in the circumferential direction. This is the preferred segmented form of the axial stator of the present invention, that is, a plurality of axial stator units are formed at intervals in the circumferential direction, which can enable a single axial stator unit to form a magnetic flux closed loop with some pole columns of the radial stator. While providing a bias magnetic flux for the radial stator, it can also effectively prevent the magnetic leakage phenomenon of the magnetic circuit of the radial stator on the outer circle of the axial stator, thereby improving the radial output force and improving the radial control performance.

[0046] 1. The present invention provides a radial / axial integrated three-degree-of-freedom control active magnetic bearing structure, which uses a 12-pole radial bearing; the thrust disk is removed and replaced by a bearing rotor, and the radial bearing and the axial bearing are integrated. Compared with the conventional active magnetic bearing, there is no need to install a thrust disk, the structure is compact, and the process is simple; compared with the usual hybrid three-degree-of-freedom magnetic bearing, there is no permanent magnet, and the bias magnetic field and the control magnetic field are provided by electromagnetic force, with large bearing capacity, high stiffness, and flexible control. This three-degree-of-freedom magnetic bearing can operate at high power and has a high critical speed, improving the stability and applicability of the magnetic levitation system.

[0047] 2. The present invention also provides two methods for energizing the bearing coils. A-A and B-B are one method of energization, and the other method of energization is to make the axial energization completely opposite, aiming to control the radial movement of the rotor, improve the radial output force, and improve the working efficiency of magnetic levitation.

[0048] The present invention solves the following technical problems:

[0049] 1. Integrate the radial bearing and the axial bearing, without a thrust disk, with a compact structure, reduce the bearing size, shorten the rotor length, increase the critical speed of the rotor, and improve the stability and applicability of the magnetic levitation system.

[0050] 2. When the upper magnetic pole in the axial direction is located at the lower end of the radial stator, magnetic leakage of the radial magnetic circuit on the outer circle of the axis is likely to occur, reducing the radial output force.

[0051] In some embodiments, in the radial cross-section, the radial stator 500 includes a first quadrant portion located in the upper right, a second quadrant portion located in the upper left, a third quadrant portion located in the lower left, and a fourth quadrant portion located in the lower right. The first quadrant portion, the second quadrant portion, the third quadrant portion, and the fourth quadrant portion are connected in sequence counterclockwise. The first quadrant portion and the third quadrant portion form a diagonal, and the second quadrant portion and the fourth quadrant portion form a diagonal. The number of the radial stator poles is 12.

[0052] This is a preferred structural form of the radial stator of the present invention. Through the radial stator poles and the radial stator yoke, a small closed-loop magnetic flux and a large closed-loop magnetic flux can be formed with the bearing rotor, so as to provide radial magnetic force for the bearing rotor. The distribution form of the 4 quadrants and the number of the radial stator poles are the preferred distribution forms of the present invention. The present invention is preferably 12 poles, that is, 12 radial stator poles.

[0053] In some embodiments, the radial stator pole 8 includes a second radial magnetic pole 82, a third radial magnetic pole 83, and a fourth radial magnetic pole 84 located in the first quadrant portion. The radial stator pole 8 further includes a fifth radial magnetic pole 85, a sixth radial magnetic pole 86, and a seventh radial magnetic pole 87 located in the fourth quadrant portion. The radial stator pole 8 further includes an eighth radial magnetic pole 88, a ninth radial magnetic pole 89, and a tenth radial magnetic pole 810 located in the third quadrant portion. The radial stator pole 8 further includes an eleventh radial magnetic pole 811, a twelfth radial magnetic pole 812, and a first radial magnetic pole 81 located in the second quadrant portion.

[0054] This is a further preferred structural form of the radial stator pole of the present invention, that is, 3 radial magnetic poles are distributed in the first quadrant portion, 3 magnetic poles are distributed in the second quadrant, 3 magnetic poles are distributed in the third quadrant, and 3 magnetic poles are distributed in the fourth quadrant, forming a 12-pole radial bearing. The processing and manufacturing process is simple, and the radial magnetic circuit control is convenient.

[0055] In some embodiments, along the circumferential direction of the radial stator, the third radial magnetic pole 83 is located between the second radial magnetic pole 82 and the fourth radial magnetic pole 84, and the circumferential width of the third radial magnetic pole 83 is respectively greater than the circumferential widths of the second radial magnetic pole 82 and the fourth radial magnetic pole 84, and the circumferential widths of the second radial magnetic pole 82 and the fourth radial magnetic pole 84 are equal.

[0056] Along the circumferential direction of the radial stator, the sixth radial pole 86 is located between the fifth radial pole 85 and the seventh radial pole 87, and the circumferential width of the sixth radial pole 86 is respectively greater than the circumferential widths of the fifth radial pole 85 and the seventh radial pole 87, and the circumferential widths of the fifth radial pole 85 and the seventh radial pole 87 are equal;

[0057] Along the circumferential direction of the radial stator, the ninth radial pole 89 is located between the eighth radial pole 88 and the tenth radial pole 810, and the circumferential width of the ninth radial pole 89 is respectively greater than the circumferential widths of the eighth radial pole 88 and the tenth radial pole 810, and the circumferential widths of the eighth radial pole 88 and the tenth radial pole 810 are equal;

[0058] Along the circumferential direction of the radial stator, the twelfth radial pole 812 is located between the eleventh radial pole 811 and the first radial pole 81, and the circumferential width of the twelfth radial pole 812 is respectively greater than the circumferential widths of the eleventh radial pole 811 and the first radial pole 81, and the circumferential widths of the eleventh radial pole 811 and the first radial pole 81 are equal.

[0059] The present invention further preferably has different circumferential widths of multiple radial stator pole columns, that is, the formed radial magnetic fluxes are not completely the same. By, for example, making the circumferential width of the third radial pole in the first quadrant greater than the second radial pole and the fourth radial pole on its both sides, the present invention can enable the magnetic flux of the second radial pole to form a closed loop via the third radial pole, and the magnetic flux of the fourth radial pole to form a closed loop via the third radial pole, so that more subdivided radial magnetic fluxes can be formed within one quadrant, thereby providing a more refined and accurate control effect for the control of the movement of the bearing rotor in the radial direction; the functions and effects of multiple radial poles in the second quadrant, the third quadrant, and the fourth quadrant are the same as above, and can also improve the accuracy of radial control.

[0060] In some embodiments, the magnetic circuits inside the first radial magnetic pole 81, the bearing rotor 9, the twelfth radial magnetic pole 812, and the radial stator yoke 1 are connected to form a closed loop, forming a radial bearing magnetic circuit 3; the magnetic circuits inside the second radial magnetic pole 82, the bearing rotor 9, the third radial magnetic pole 83, and the radial stator yoke 1 are also connected to form a closed-loop radial bearing magnetic circuit 3; the magnetic circuits inside the third radial magnetic pole 83, the bearing rotor 9, the fourth radial magnetic pole 84, and the radial stator yoke 1 are also connected to form a closed-loop radial bearing magnetic circuit 3; the magnetic circuits inside the fifth radial magnetic pole 85, the bearing rotor 9, the sixth radial magnetic pole 86, and the radial stator yoke 1 are also connected to form a closed-loop radial bearing magnetic circuit 3; the magnetic circuits inside the sixth radial magnetic pole 86, the bearing rotor 9, the seventh radial magnetic pole 87, and the radial stator yoke 1 are also connected to form a closed-loop radial bearing magnetic circuit 3; the magnetic circuits inside the eighth radial magnetic pole 88, the bearing rotor 9, the ninth radial magnetic pole 89, and the radial stator yoke 1 are also connected to form a closed-loop radial bearing magnetic circuit 3; the magnetic circuits inside the ninth radial magnetic pole 89, the bearing rotor 9, the tenth radial magnetic pole 810, and the radial stator yoke 1 are also connected to form a closed-loop radial bearing magnetic circuit 3; the magnetic circuits inside the eleventh radial magnetic pole 811, the bearing rotor 9, the twelfth radial magnetic pole 812, and the radial stator yoke 1 are also connected to form a closed-loop radial bearing magnetic circuit 3.

[0061] The present invention further preferably enables a closed-loop magnetic flux to be formed between the second radial magnetic pole and the third radial magnetic pole in the first quadrant, capable of providing a radially inward magnetic flux on the second radial magnetic pole and a radially outward magnetic flux on the third radial magnetic pole. The same is true for the magnetic poles in the second quadrant, the third quadrant, and the fourth quadrant. Thus, the radial magnetic flux directions on the two relatively narrow radial magnetic poles are the same, while the radial magnetic flux on the relatively wide radial magnetic pole is opposite to the magnetic fluxes on the two relatively narrow radial magnetic poles on its both sides. Therefore, it can be controlled according to the magnitude of the current in the windings on the corresponding radial magnetic poles, so as to control whether the bearing rotor moves diagonally upward to the right or diagonally downward to the left in the first quadrant. The combined control of multiple magnetic poles and multiple windings can improve the control accuracy; enabling the radial magnetic flux of each radial magnetic pole to enhance or weaken the radial magnetic flux uniformly when superimposed (coupled) with the axial offset magnetic flux (the directions of the radial magnetic fluxes of each radial magnetic pole are the same as the direction of the axial offset magnetic flux), can improve the radial output force and the control efficiency.

[0062] In some embodiments, the first axial stator unit 61 faces the first radial magnetic pole 81 in the second quadrant portion and the second radial magnetic pole 82 in the first quadrant portion, and provides a bias magnetic path for the first radial magnetic pole 81 and the second radial magnetic pole 82 through the first axial stator unit 61; the second axial stator unit 62 faces the third radial magnetic pole 83 in the first quadrant portion, and provides a bias magnetic path for the third radial magnetic pole 83 through the second axial stator unit 62;

[0063] The third axial stator unit 63 faces the fourth radial magnetic pole 84 in the first quadrant portion and the fifth radial magnetic pole 85 in the fourth quadrant portion, and provides a bias magnetic path for the fourth radial magnetic pole 84 and the fifth radial magnetic pole 85 through the third axial stator unit 63; the fourth axial stator unit 64 faces the sixth radial magnetic pole 86 in the fourth quadrant portion, and provides a bias magnetic path for the sixth radial magnetic pole 86 through the fourth axial stator unit 64;

[0064] The fifth axial stator unit 65 faces the seventh radial magnetic pole 87 in the fourth quadrant portion and the eighth radial magnetic pole 88 in the third quadrant portion, and provides a bias magnetic path for the seventh radial magnetic pole 87 and the eighth radial magnetic pole 88 through the fifth axial stator unit 65; the sixth axial stator unit 66 faces the ninth radial magnetic pole 89 in the third quadrant portion, and provides a bias magnetic path for the ninth radial magnetic pole 89 through the sixth axial stator unit 66;

[0065] The seventh axial stator unit 67 faces the tenth radial magnetic pole 810 in the third quadrant portion and the eleventh radial magnetic pole 811 in the second quadrant portion, and provides a bias magnetic path for the tenth radial magnetic pole 810 and the eleventh radial magnetic pole 811 through the seventh axial stator unit 67; the eighth axial stator unit 68 faces the twelfth radial magnetic pole 812 in the second quadrant portion, and provides a bias magnetic path for the twelfth radial magnetic pole 812 through the eighth axial stator unit 68.

[0066] This is the preferred distribution and corresponding relationship between the segmented axial stator units of the present invention and multiple radial magnetic poles, that is, the first axial stator unit faces the radial magnetic poles in the first and second quadrants to provide bias magnetic flux thereto; the second axial stator unit faces the radial magnetic pole in the first quadrant to provide bias magnetic flux thereto; the third axial stator unit faces the radial magnetic poles in the first and fourth quadrants to provide bias magnetic flux thereto; the fourth axial stator unit faces the radial magnetic pole in the fourth quadrant to provide bias magnetic flux thereto; the fifth axial stator unit faces the radial magnetic poles in the fourth and third quadrants to provide bias magnetic flux thereto; the sixth axial stator unit faces the radial magnetic pole in the third quadrant to provide bias magnetic flux thereto; the seventh axial stator unit faces the radial magnetic poles in the third and second quadrants to provide bias magnetic flux thereto; the eighth axial stator unit faces the radial magnetic poles in the second and fourth quadrants to provide bias magnetic flux thereto.

[0067] In some embodiments, the bias magnetic paths provided by the first axial stator unit 61 to the first radial magnetic pole 81 and the second radial magnetic pole 82 both extend in the radial direction towards the center of the rotating shaft 2; the bias magnetic path provided by the second axial stator unit 62 to the third radial magnetic pole 83 extends in the radial direction away from the center of the rotating shaft 2; the bias magnetic paths provided by the third axial stator unit 63 to the fourth radial magnetic pole 84 and the fifth radial magnetic pole 85 both extend in the radial direction towards the center of the rotating shaft 2; the bias magnetic path provided by the fourth axial stator unit 64 to the sixth radial magnetic pole 86 extends in the radial direction away from the center of the rotating shaft 2;

[0068] the bias magnetic paths provided by the fifth axial stator unit 65 to the seventh radial magnetic pole 87 and the eighth radial magnetic pole 88 both extend in the radial direction towards the center of the rotating shaft 2; the bias magnetic path provided by the sixth axial stator unit 66 to the ninth radial magnetic pole 89 extends in the radial direction away from the center of the rotating shaft 2; the bias magnetic paths provided by the seventh axial stator unit 67 to the tenth radial magnetic pole 810 and the eleventh radial magnetic pole 811 both extend in the radial direction towards the center of the rotating shaft 2; the bias magnetic path provided by the eighth axial stator unit 68 to the twelfth radial magnetic pole 812 extends in the radial direction away from the center of the rotating shaft 2.

[0069] This is the further preferred flux relationship between the axial stator unit of the present invention and the radial magnetic poles in each different quadrant, that is, the biasing fluxes provided by the first axial stator unit and the third axial stator unit are directed radially inwards (the same as the radial fluxes of the narrower first radial magnetic pole 81, the second radial magnetic pole 82, the fourth radial magnetic pole 84, and the fifth radial magnetic pole 85, all directed radially inwards), and the biasing fluxes provided by the second axial stator unit and the fourth axial stator unit are directed radially outwards (the same as the radial fluxes of the wider third radial magnetic pole 83 and the sixth radial magnetic pole 86, both directed radially inwards). Combining with the distribution form of the radial magnetic poles in different quadrants of the present invention, the radial fluxes provided by the radial pole columns in each quadrant are the same as the directions of the biasing radial fluxes provided by the segmented axial stator units in that quadrant (that is, all directed radially inwards or all directed radially outwards). The finally formed radial output force is effectively enhanced. Through such a segmented axial stator, different distribution forms of the radial pole columns, and the energization method, the present invention can maximize the enhancement of the radial output force, improve the effect of the magnetic suspension bearing, and improve the efficiency.

[0070] The structure of the active three-degree-of-freedom magnetic bearing of the present invention is as Figure 1 shown. Compared with the traditional active magnetic bearing structure, the thrust disk is removed and replaced by the bearing rotor. The axial stator is located at both ends of the radial stator, and the radial bearing and the axial bearing are integrated. This structure mainly consists of a radial stator yoke 1; a bearing rotor 9; a radial winding 5; a first axial iron core 6; a first axial winding 7; a second axial iron core 11; a second axial winding 12; a radial bearing stator magnetic pole (radial stator pole column 8) and other parts.

[0071] Under this structure, the radial bearing magnetic poles are arranged in the form of NSNNSN (or SNSSNS). If the axial bearing is a complete circle, the axial bearing will partially cancel and partially enhance the flux of the radial magnetic circuit, resulting in non-uniform coupling of the magnetic poles of the radial bearing, and thus it is difficult to control the output force. In this structure, the axial bearing is segmented. As Figure 2 shown in the A-A cross-section in and the two segmented axial bearings shown in the B-B cross-section will both enhance the flux of the corresponding radial magnetic circuit. In this way, the mutual influence between the axial flux and the radial flux will be smaller, thereby reducing the overall volume of the bearing while minimizing the control difficulty.

[0072] The magnetic flux of the first radial bearing magnetic circuit of this structure has four groups of double cycles: the second radial magnetic pole 82 → bearing rotor 9 → the third radial magnetic pole 83 → radial stator yoke 1 → the second radial magnetic pole 82 (cycle 1) + the fourth radial magnetic pole 84 → bearing rotor 9 → the third radial magnetic pole 83 → radial stator yoke 1 → the fourth radial magnetic pole 84 (cycle 2). The number of this double cycle is one-third of the number of the radial bearing stator magnetic poles (radial stator pole columns 8). The number of the radial stator pole columns 8 is a, a is an even number and a multiple of 3. In the present invention, it is preferably 12.

[0073] The magnetic flux of the axial bearing magnetic circuit of this structure is as follows: at section A, the first axial iron core 6 → the twelfth radial magnetic pole 812 → bearing rotor 9 → the first axial iron core 6 (cycle); at section B, the first axial iron core 6 → the third radial magnetic pole 83 → bearing rotor 9 → the first axial iron core 6 (cycle), and the same applies to other sections.

[0074] The magnetic poles of the first axial stator unit 61 cover the first radial magnetic pole 81 and the second radial magnetic pole 82; the magnetic poles of the second axial stator unit 62 cover the third radial magnetic pole 83; the magnetic poles of the third axial stator unit 63 cover the fourth radial magnetic pole 84 and the fifth radial magnetic pole 85; the magnetic poles of the fourth axial stator unit 64 cover the sixth radial magnetic pole 86; the magnetic poles of the fifth axial stator unit 65 cover the seventh radial magnetic pole 87 and the eighth radial magnetic pole 88; the magnetic poles of the sixth axial stator unit 66 cover the ninth radial magnetic pole 89; the magnetic poles of the seventh axial stator unit 67 cover the tenth radial magnetic pole 810 and the eleventh radial magnetic pole 811; the magnetic poles of the eighth axial stator unit 68 cover the twelfth radial magnetic pole 812.

[0075] When controlling this bearing, separate control of the radial and axial directions can still be achieved. The method is simple, and the azimuth of the radial movement of the rotating shaft can be controlled in a wide range. For this three-degree-of-freedom magnetic bearing, the radial bearing and the axial bearing are integrated, the length of the rotor is shortened, the critical speed of the rotor is increased, the magnetic poles of the axial bearing are divided into blocks, the magnetic flux leakage phenomenon of the radial magnetic circuit on the outer circle of the axial stator is avoided, the air-gap magnetic field on the radial magnetic poles is enhanced, and stable suspension in the radial direction is achieved.

[0076] In some embodiments, the first axial stator 300 includes a first axial iron core 6 and a first axial winding 7. The first axial iron core 6 has an annular structure and includes a first main body portion 6a, a first annular portion 6b, and a second annular portion 6c. The first main body portion 6a is a disk structure having a first central hole through which the rotating shaft 2 passes. The second annular portion 6c is located radially outside the first annular portion 6b. One end of the first annular portion 6b is connected to the first main body portion 6a and the other end extends toward the bearing rotor 9 to face the bearing rotor 9. One end of the second annular portion 6c is connected to the first main body portion 6a and the other end extends toward the radial iron core 10 to face the radial iron core 10, so as to form a first receiving groove 6d between the radially outer side of the first annular portion 6b and the radially inner side of the second annular portion 6c. The first axial winding 7 is wound around the second annular portion 6c.

[0077] This is a preferred structural form of the first axial stator of the present invention. The first receiving groove for accommodating the first axial winding can be formed by the first annular portion and the second annular portion. The first annular portion faces the bearing rotor to accommodate the magnetic path passing through. The second annular portion faces the radial iron core, which can effectively improve the radial iron core and the second annular portion, so that the second annular portion, the radial iron core, the bearing rotor, the first annular portion, and the first main body portion form a closed-loop magnetic path. Such a structure can enable the first axial stator to provide a radial bias magnetic flux for the radial stator, so that the first axial stator and the radial stator are integrated into an integral structure, effectively eliminating structures such as a thrust disk, a permanent magnet, and a bias stator, with a compact structure and effectively reduced volume.

[0078] In some embodiments, the first annular portion 6b extends along the axial direction of the rotating shaft 2 and is spaced from the bearing rotor 9 by a third preset distance to form a first axial working gap 16. The second annular portion 6c also extends along the axial direction of the rotating shaft 2 and is spaced from the radial iron core 10 by a fourth preset distance to form a second axial working gap 19. This is a preferred structural form of the first annular portion and the second annular portion of the present invention, that is, the first annular portion extends axially and forms a first axial working gap with the bearing rotor, so that a magnetic flux can pass between the first annular portion and the bearing rotor, and the first annular portion does not rotate with the bearing rotor. The second annular portion is spaced from the radial iron core by the second axial working gap, so that a magnetic flux can pass between the second annular portion and the radial iron core, and the second annular portion does not form friction or magnetic leakage with the radial stator.

[0079] In some embodiments, the second axial stator 400 includes a second axial iron core 11 and a second axial winding 12. The second axial iron core 11 is of an annular structure and includes a second main body portion 11a, a third annular portion 11b, and a fourth annular portion 11c. The second main body portion 11a is of a disc structure having a second central hole through which the rotating shaft 2 passes. One end of the third annular portion 11b is connected to the second main body portion 11a and the other end extends towards the bearing rotor 9 to face the bearing rotor 9. One end of the fourth annular portion 11c is connected to the second main body portion 11a and the other end extends towards the radial iron core 10 to face the radial iron core 10. And the fourth annular portion 11c is located radially outside the third annular portion 11b to form a second accommodation groove 11d between the radially outer side of the third annular portion 11b and the radially inner side of the fourth annular portion 11c. The second axial winding 12 is wound around the fourth annular portion 11c.

[0080] This is a preferred structural form of the second axial stator of the present invention. The second accommodation groove for accommodating the second axial winding can be formed by the third annular portion and the fourth annular portion. And the third annular portion faces the bearing rotor to accommodate the magnetic path to pass through. The fourth annular portion faces the radial iron core, which can effectively improve the radial iron core and the fourth annular portion, so that a closed-loop magnetic path is formed by the fourth annular portion, the radial iron core, the bearing rotor, the third annular portion, and the second main body portion. And such a structure can enable the second axial stator to provide a radial bias magnetic flux for the radial stator, so that the second axial stator and the radial stator are integrated into an integral structure, effectively eliminating structures such as a thrust disc, a permanent magnet, and a bias stator, with a compact structure and an effectively reduced volume.

[0081] In some embodiments, the third annular portion 11b extends along the axial direction of the rotating shaft 2 and is spaced from the bearing rotor 9 by a fifth preset distance to form a first axial working gap 16. The fourth annular portion 11c also extends along the axial direction of the rotating shaft 2 and is spaced from the radial iron core 10 by a sixth preset distance to form a second axial working gap 19. This is a preferred structural form of the third annular portion and the fourth annular portion of the present invention, that is, the third annular portion extends axially and forms a first axial working gap with the bearing rotor, enabling a magnetic flux to pass between the third annular portion and the bearing rotor, and the third annular portion does not rotate with the bearing rotor. The fourth annular portion is spaced from the radial iron core by the second axial working gap, enabling a magnetic flux to pass between the fourth annular portion and the radial iron core, and the fourth annular portion does not form friction or magnetic leakage with the radial stator.

[0082] In some embodiments, the energization directions of the first axial winding 7 and the second axial winding 12 are opposite; the radial winding 5 is simultaneously located radially outside the second annular portion 6c and the fourth annular portion 11c, and both the second annular portion 6c and the fourth annular portion 11c are opposite to the radial stator pole column 8. The present invention also arranges the radial winding on the radial outside of the first axial iron core and the second axial iron core, and both the second annular portion and the fourth annular portion are opposite to the radial stator pole column, so that compared with the existing solution where the upper magnetic pole of the axial stator is located beside the radial stator yoke (i.e., the upper magnetic pole of the existing axial stator is located on the axial side of the radial stator yoke), it can effectively reduce the magnetic leakage of the radial magnetic circuit in the axial direction and effectively prevent the unevenness of the axial output force in the circumferential direction.

[0083] The present invention also provides a motor, which includes the magnetic levitation active three-degree-of-freedom bearing described in any one of the preceding items.

[0084] Advantages of the present invention:

[0085] 1. By adopting a 12-stage radial bearing, the processing and manufacturing process is simple, and the radial magnetic circuit control is convenient. The axial stator magnetic poles adopt a segmented structure, which avoids the magnetic leakage phenomenon of the radial magnetic circuit on the outer circle of the axial stator and only enhances the air-gap magnetic field on the radial magnetic poles.

[0086] 2. Without permanent magnets, it has low cost, convenient assembly, large bearing capacity, and can operate at high power; the integration of the radial and axial directions is high, without a thrust disk, reducing costs, having a compact structure, simple process, high critical speed, and stable performance.

[0087] The present invention also provides a compressor, which includes the magnetic levitation active three-degree-of-freedom bearing described in any one of the preceding items.

[0088] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. The above is only the preferred implementation manner of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A magnetic levitation active three-degree-of-freedom bearing, characterized in that: Comprising: An axial magnetic bearing (100), a radial magnetic bearing (200) and a bearing rotor (9). The axial magnetic bearing (100) and the radial magnetic bearing (200) are both sleeved on the outer periphery of a rotating shaft (2). The axial magnetic bearing (100) includes a first axial stator (300) and a second axial stator (400). The radial magnetic bearing (200) includes a radial stator (500). The bearing rotor (9) is sleeved on the outer periphery of the rotating shaft (2) and can rotate together with the rotating shaft (2). The radial stator (500) is located on the outer periphery of the bearing rotor (9) and can apply a radial electromagnetic force to the bearing rotor (9). Along the axial direction of the rotating shaft (2), at least part of the structure of the first axial stator (300) is located at one axial end of the bearing rotor (9), and at least part of the structure of the second axial stator (400) is located at the other axial end of the bearing rotor (9). The first axial stator (300) and the second axial stator (400) can apply an axial electromagnetic force to the bearing rotor (9), so that the bias magnetic flux of the radial magnetic bearing (200) is provided by the axial magnetic bearing (100). The first axial stator (300) and the second axial stator (400) are both block structures arranged at intervals in the circumferential direction; The radial stator (500) includes a radial iron core (10) and a radial winding (5). The radial iron core (10) is a ring structure and is sleeved on the radial outer side of the bearing rotor (9). The radial iron core (10) includes a radial stator yoke (1) and radial stator pole columns (8). The radial stator yoke (1) is an annular structure. The radially outer ends of the radial stator pole columns are connected to the radial stator yoke (1), and the radially inner ends protrude towards the bearing rotor (9) and have a radial working gap (15) with the bearing rotor (9). The radial winding (5) is wound around each radial stator pole column. The number of the radial stator pole columns is 12, that is, a radial 12-pole stator is formed; The first axial stator (300) includes a first axial iron core (6) and a first axial winding (7). The first axial iron core (6) has an annular structure and includes a first main body portion (6a), a first annular portion (6b), and a second annular portion (6c). The first main body portion (6a) has a disc structure with a first central hole, and the first central hole accommodates the rotation shaft (2) passing therethrough. The second annular portion (6c) is located radially outside the first annular portion (6b). One end of the first annular portion (6b) is connected to the first main body portion (6a), and the other end extends toward the bearing rotor (9) to face the bearing rotor (9). One end of the second annular portion (6c) is connected to the first main body portion (6a), and the other end extends toward the radial iron core (10) to face the radial iron core (10), so as to form a first accommodation groove (6d) between the radially outer side of the first annular portion (6b) and the radially inner side of the second annular portion (6c). The first axial winding (7) is wound around the second annular portion (6c); The second axial stator (400) includes a second axial iron core (11) and a second axial winding (12). The second axial iron core (11) has an annular structure and includes a second main body portion (11a), a third annular portion (11b), and a fourth annular portion (11c). The second main body portion (11a) has a disc structure with a second central hole, and the second central hole accommodates the rotation shaft (2) passing therethrough. One end of the third annular portion (11b) is connected to the second main body portion (11a), and the other end extends toward the bearing rotor (9) to face the bearing rotor (9). One end of the fourth annular portion (11c) is connected to the second main body portion (11a), and the other end extends toward the radial iron core (10) to face the radial iron core (10), and the fourth annular portion (11c) is located radially outside the third annular portion (11b), so as to form a second accommodation groove (11d) between the radially outer side of the third annular portion (11b) and the radially inner side of the fourth annular portion (11c). The second axial winding (12) is wound around the fourth annular portion (11c); The energization directions of the first axial winding (7) and the second axial winding (12) are opposite; the radial winding (5) is simultaneously located radially outside the second annular portion (6c) and the fourth annular portion (11c), and both the second annular portion (6c) and the fourth annular portion (11c) face the radial stator pole column (8).

2. The magnetic levitation active three-degree-of-freedom bearing according to claim 1, wherein: The structures of the first axial stator (300) and the second axial stator (400) are the same, and both include a first axial stator unit (61), a second axial stator unit (62), a third axial stator unit (63), a fourth axial stator unit (64), a fifth axial stator unit (65), a sixth axial stator unit (66), a seventh axial stator unit (67), and an eighth axial stator unit (68) that are sequentially arranged at intervals in the circumferential direction.

3. The magnetic levitation active three-degree-of-freedom bearing according to claim 2, wherein: In the radial cross-section, the radial stator (500) includes a first quadrant part located in the upper right, a second quadrant part located in the upper left, a third quadrant part located in the lower left, and a fourth quadrant part located in the lower right. The first quadrant part, the second quadrant part, the third quadrant part, and the fourth quadrant part are sequentially connected in the counterclockwise direction. The first quadrant part and the third quadrant part form a diagonal, and the second quadrant part and the fourth quadrant part form a diagonal.

4. The magnetic levitation active three-degree-of-freedom bearing according to claim 3, wherein: The radial stator pole column (8) includes a second radial magnetic pole (82), a third radial magnetic pole (83), and a fourth radial magnetic pole (84) located in the first quadrant part. The radial stator pole column (8) further includes a fifth radial magnetic pole (85), a sixth radial magnetic pole (86), and a seventh radial magnetic pole (87) located in the fourth quadrant part. The radial stator pole column (8) further includes an eighth radial magnetic pole (88), a ninth radial magnetic pole (89), and a tenth radial magnetic pole (810) located in the third quadrant part. The radial stator pole column (8) further includes an eleventh radial magnetic pole (811), a twelfth radial magnetic pole (812), and a first radial magnetic pole (81) located in the second quadrant part.

5. The magnetic levitation active three-degree-of-freedom bearing according to claim 4, wherein: Along the circumferential direction of the radial stator, the third radial magnetic pole (83) is located between the second radial magnetic pole (82) and the fourth radial magnetic pole (84), and the circumferential width of the third radial magnetic pole (83) is respectively greater than the circumferential widths of the second radial magnetic pole (82) and the fourth radial magnetic pole (84). The circumferential widths of the second radial magnetic pole (82) and the fourth radial magnetic pole (84) are equal. Along the circumferential direction of the radial stator, the sixth radial magnetic pole (86) is located between the fifth radial magnetic pole (85) and the seventh radial magnetic pole (87), and the circumferential width of the sixth radial magnetic pole (86) is respectively greater than the circumferential widths of the fifth radial magnetic pole (85) and the seventh radial magnetic pole (87). The circumferential widths of the fifth radial magnetic pole (85) and the seventh radial magnetic pole (87) are equal. Along the circumferential direction of the radial stator, the ninth radial pole (89) is located between the eighth radial pole (88) and the tenth radial pole (810), and the circumferential width of the ninth radial pole (89) is greater than the circumferential widths of the eighth radial pole (88) and the tenth radial pole (810) respectively, and the circumferential widths of the eighth radial pole (88) and the tenth radial pole (810) are equal; Along the circumferential direction of the radial stator, the twelfth radial pole (812) is located between the eleventh radial pole (811) and the first radial pole (81), and the circumferential width of the twelfth radial pole (812) is greater than the circumferential widths of the eleventh radial pole (811) and the first radial pole (81) respectively, and the circumferential widths of the eleventh radial pole (811) and the first radial pole (81) are equal.

6. The magnetic levitation active three-degree-of-freedom bearing according to claim 5, characterized in that: The magnetic paths inside the first radial pole (81), the bearing rotor (9), the twelfth radial pole (812) and the radial stator yoke (1) are connected to form a closed loop, forming a radial bearing magnetic path (3); the magnetic paths inside the second radial pole (82), the bearing rotor (9), the third radial pole (83) and the radial stator yoke (1) are also connected to form a closed-loop radial bearing magnetic path (3); the magnetic paths inside the third radial pole (83), the bearing rotor (9), the fourth radial pole (84) and the radial stator yoke (1) are also connected to form a closed-loop radial bearing magnetic path (3); the magnetic paths inside the fifth radial pole (85), the bearing rotor (9), the sixth radial pole (86) and the radial stator yoke (1) are also connected to form a closed-loop radial bearing magnetic path (3); the magnetic paths inside the sixth radial pole (86), the bearing rotor (9), the seventh radial pole (87) and the radial stator yoke (1) are also connected to form a closed-loop radial bearing magnetic path (3); the magnetic paths inside the eighth radial pole (88), the bearing rotor (9), the ninth radial pole (89) and the radial stator yoke (1) are also connected to form a closed-loop radial bearing magnetic path (3); the magnetic paths inside the ninth radial pole (89), the bearing rotor (9), the tenth radial pole (810) and the radial stator yoke (1) are also connected to form a closed-loop radial bearing magnetic path (3); the magnetic paths inside the eleventh radial pole (811), the bearing rotor (9), the twelfth radial pole (812) and the radial stator yoke (1) are also connected to form a closed-loop radial bearing magnetic path (3).

7. The magnetic levitation active three-degree-of-freedom bearing according to claim 6, characterized in that: The first axial stator unit (61) faces the first radial magnetic pole (81) in the second quadrant portion and the second radial magnetic pole (82) in the first quadrant portion, and provides a bias magnetic path for the first radial magnetic pole (81) and the second radial magnetic pole (82) through the first axial stator unit (61); the second axial stator unit (62) faces the third radial magnetic pole (83) in the first quadrant portion, and provides a bias magnetic path for the third radial magnetic pole (83) through the second axial stator unit (62); The third axial stator unit (63) faces the fourth radial magnetic pole (84) in the first quadrant portion and the fifth radial magnetic pole (85) in the fourth quadrant portion, and provides a bias magnetic path for the fourth radial magnetic pole (84) and the fifth radial magnetic pole (85) through the third axial stator unit (63); the fourth axial stator unit (64) faces the sixth radial magnetic pole (86) in the fourth quadrant portion, and provides a bias magnetic path for the sixth radial magnetic pole (86) through the fourth axial stator unit (64); The fifth axial stator unit (65) faces the seventh radial magnetic pole (87) in the fourth quadrant portion and the eighth radial magnetic pole (88) in the third quadrant portion, and provides a bias magnetic path for the seventh radial magnetic pole (87) and the eighth radial magnetic pole (88) through the fifth axial stator unit (65); the sixth axial stator unit (66) faces the ninth radial magnetic pole (89) in the third quadrant portion, and provides a bias magnetic path for the ninth radial magnetic pole (89) through the sixth axial stator unit (66); The seventh axial stator unit (67) faces the tenth radial magnetic pole (810) in the third quadrant portion and the eleventh radial magnetic pole (811) in the second quadrant portion, and provides a bias magnetic path for the tenth radial magnetic pole (810) and the eleventh radial magnetic pole (811) through the seventh axial stator unit (67); the eighth axial stator unit (68) faces the twelfth radial magnetic pole (812) in the second quadrant portion, and provides a bias magnetic path for the twelfth radial magnetic pole (812) through the eighth axial stator unit (68).

8. The magnetic levitation active three-degree-of-freedom bearing according to claim 7, wherein: The bias magnetic paths provided by the first axial stator unit (61) for the first radial magnetic pole (81) and the second radial magnetic pole (82) both extend in the radial direction towards the center of the rotation shaft (2); the bias magnetic path provided by the second axial stator unit (62) for the third radial magnetic pole (83) extends in the radial direction away from the center of the rotation shaft (2); the bias magnetic paths provided by the third axial stator unit (63) for the fourth radial magnetic pole (84) and the fifth radial magnetic pole (85) both extend in the radial direction towards the center of the rotation shaft (2); the bias magnetic path provided by the fourth axial stator unit (64) for the sixth radial magnetic pole (86) extends in the radial direction away from the center of the rotation shaft (2). The bias magnetic paths provided by the fifth axial stator unit (65) for the seventh radial magnetic pole (87) and the eighth radial magnetic pole (88) both extend in the radial direction towards the center of the rotation shaft (2); the bias magnetic path provided by the sixth axial stator unit (66) for the ninth radial magnetic pole (89) extends in the radial direction away from the center of the rotation shaft (2); the bias magnetic paths provided by the seventh axial stator unit (67) for the tenth radial magnetic pole (810) and the eleventh radial magnetic pole (811) both extend in the radial direction towards the center of the rotation shaft (2); the bias magnetic path provided by the eighth axial stator unit (68) for the twelfth radial magnetic pole (812) extends in the radial direction away from the center of the rotation shaft (2).

9. The magnetic levitation active three-degree-of-freedom bearing according to claim 1, wherein: The first annular portion (6b) extends along the axial direction of the rotation shaft (2) and is spaced apart from the bearing rotor (9) by a third preset distance to form a first axial working gap (16); the second annular portion (6c) also extends along the axial direction of the rotation shaft (2) and is spaced apart from the radial iron core (10) by a fourth preset distance to form a second axial working gap (19).

10. The magnetic levitation active three-degree-of-freedom bearing according to claim 1, wherein: The third annular portion (11b) extends along the axial direction of the rotation shaft (2) and is spaced apart from the bearing rotor (9) by a fifth preset distance to form a first axial working gap (16); the fourth annular portion (11c) also extends along the axial direction of the rotation shaft (2) and is spaced apart from the radial iron core (10) by a sixth preset distance to form a second axial working gap (19).

11. A motor, characterized in that: Comprising the magnetic levitation active three-degree-of-freedom bearing according to any one of claims 1-10.

12. A compressor, characterized in that: Comprising the magnetic levitation active three-degree-of-freedom bearing according to any one of claims 1-10.

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