Magnetic levitation active three-degree-of-freedom bearings, compressors, and motors

Abstract

The present invention provides a magnetically levitated active three-degree-of-freedom bearing, a compressor, and a motor. The magnetically levitated active three-degree-of-freedom bearing includes a bearing rotor, a radial stator assembly, and two axial stator assemblies. The radial stator assembly includes a radial stator having 16 poles. The 16 poles are centrosymmetrical about the center of the rotating shaft and distributed in four quadrants. Each quadrant has a middle pole and a first side pole and a second side pole on either side of the middle pole. The four poles are symmetrical about the angular bisector of the corresponding quadrant. Within the same quadrant, the polarity formed by the first side pole and the adjacent middle pole, the two middle poles, and the second side pole and the corresponding middle pole are all opposite. The present invention eliminates the need for a separate thrust plate to be assembled on the rotating shaft, resulting in a more compact structure and simplified process. This effectively reduces the bearing volume, shortens the rotating shaft length, increases the critical speed of the rotor, and improves the operational stability of the magnetic levitation system.

Description

Technical Field

[0001] The present invention belongs to the technical field of magnetic suspension bearings, and in particular relates to a magnetic suspension active three-degree-of-freedom bearing, a compressor, and a motor. Background Art

[0002] Magnetic bearings (abbreviated as magnetic bearings) use electromagnetic forces on the rotor to suspend the rotating shaft, maintaining a non-contact state between the shaft and the stator. Therefore, they have the advantages of being wear-free, high-speed, high-precision, and long-life. Magnetic bearings can be divided into three categories based on their operating principle: active magnetic bearings, passive magnetic bearings, and hybrid magnetic bearings. Magnetic bearings are further divided into radial magnetic bearings and axial magnetic bearings. Radial magnetic bearings adjust the radial position of the rotating shaft through electromagnetic forces between them and the radial rotor, while axial magnetic bearings adjust the axial position of the rotating shaft through electromagnetic forces between them and the thrust plate on the rotating shaft. In a magnetic levitation system, radial magnetic bearings and axial magnetic bearings are simultaneously configured at both ends of the rotating shaft, thereby achieving adjustment of the three-degree-of-freedom directional position of the rotating shaft. However, the radial magnetic levitation bearings and axial magnetic levitation bearings that are independently arranged have a low degree of integration and occupy the size of the rotating shaft, resulting in a relatively large rotating shaft length, which is not conducive to improving the critical speed of the rotor. Of course, in some existing technologies, there are also three-degree-of-freedom magnetic bearings that integrate radial magnetic levitation bearings and axial magnetic levitation bearings into a whole. However, the structural design of the radial bearings and axial bearings in this three-degree-of-freedom magnetic bearing is not reasonable enough, resulting in the magnetic lines of force of the radial bearing and the magnetic lines of force of the axial bearing each forming a path through the corresponding rotor parts, such as the radial rotor or the thrust plate. The overall structure is complex, the processing and manufacturing process is complex, the assembly is difficult, and the degree of integration is relatively low. Summary of the Invention

[0003] Therefore, the present invention provides a magnetically levitated active three-degree-of-freedom bearing, a compressor, and a motor, which can solve the technical problems in the prior art that the structural design of the radial bearing and the axial bearing in the three-degree-of-freedom magnetic bearing is not reasonable, resulting in the magnetic lines of force of the radial bearing and the magnetic lines of force of the axial bearing each forming a path through the corresponding rotor parts, the overall structure is complex, the processing and manufacturing process is complex, the assembly is difficult, and the degree of integration is low.

[0004] In order to solve the above problems, the present invention provides a magnetic levitation active three-degree-of-freedom bearing, comprising a bearing rotor for fixedly sleeved with a rotating shaft, a radial stator assembly sleeved on the radial outside of the bearing rotor, and a first axial stator assembly and a second axial stator assembly respectively located at both axial ends of the bearing rotor, wherein the first axial stator assembly and the second axial stator assembly respectively form an axial magnetic circuit with the bearing rotor and the radial stator assembly to adjust the axial position of the bearing rotor, and a radial magnetic circuit is formed between the radial stator assembly and the bearing rotor to adjust the radial position of the bearing rotor, and the radial stator assembly includes a radial stator, which has 16 poles extending toward one side of the bearing rotor. In the axial projection of the rotating shaft, the 16 poles are centrally symmetrical about the center of the rotating shaft and are distributed in 4 In the quadrant, each quadrant has two middle poles and a first side pole and a second side pole on both sides of the middle poles. The first side pole, the second side pole and the two middle poles are all symmetrical about the angular bisector of the corresponding quadrant, and in the same quadrant, the polarities formed by the first side pole and the adjacent middle pole, the two middle poles, and the second side pole and the corresponding middle pole are all opposite. The first axial stator assembly and the second axial stator assembly both have six axial poles arranged at intervals around the rotating shaft, and an axial coil is wound around each axial pole. The first side poles and the second side poles arranged adjacent to each other in the two adjacent quadrants form a side pole group, and the six axial poles correspond one-to-one to the four side pole groups and the poles with the same polarity in the eight middle poles.

[0005] In some embodiments, a circumferential width of the middle pole is greater than a circumferential width of the first side pole or the second side pole.

[0006] In some embodiments, the circumferential width of the middle pole is twice the circumferential width of the first side pole or the second side pole.

[0007] In some embodiments, a radial coil is wound around each pole, the radial coil wound around the first side pole and the radial coil wound around the second side pole are connected in series, and the radial coils wound around the two middle poles are connected in series.

[0008] In some embodiments, the first axial stator assembly includes a first axial stator having a first inner magnetic ring and a first axial pole, and the axial coil is respectively wound around each of the first axial poles, wherein a first axial inner working gap is formed between the first inner magnetic ring and the left end face of the bearing rotor, a first axial outer working gap is formed between the first axial pole and the left end face of the radial stator, and the first axial pole is located radially inside the radial coil.

[0009] In some embodiments, the second axial stator assembly includes a second axial stator having a second inner magnetic ring and a second axial pole, and the axial coil is respectively wound around each of the second axial poles, wherein a second axial inner working gap is formed between the second inner magnetic ring and the right end face of the bearing rotor, a second axial outer working gap is formed between the second axial pole and the right end face of the radial stator, and the second axial pole is located radially inside the radial coil.

[0010] In some embodiments, control of the radial coil wound on the middle pole in each quadrant is independent of control of the radial coil wound on the first side pole and the second side pole.

[0011] In some embodiments, the current flowing through the axial coils in the first axial stator assembly is opposite to the current flowing through the axial coils in the second axial stator assembly.

[0012] The present invention also provides a compressor comprising the above-mentioned magnetically suspended active three-degree-of-freedom bearing.

[0013] The present invention also provides a motor comprising the above-mentioned magnetically suspended active three-degree-of-freedom bearing.

[0014] The present invention provides a magnetic levitation active three-degree-of-freedom bearing, compressor, and motor. No thrust plate needs to be separately assembled on the rotating shaft, and the overall structure and processing technology are simplified, which is convenient for assembly. The degree of integration is high, the structure is more compact, and the bearing volume is effectively reduced, the rotating shaft length is shortened, the critical speed of the rotor is increased, and the operating stability of the magnetic levitation system is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the internal structure of a magnetically suspended active three-degree-of-freedom bearing according to an embodiment of the present invention, wherein the dotted arrows in the figure indicate the flow direction of the axial magnetic circuit;

[0016] Figure 2 for Figure 1The relative position relationship between the radial stator and the bearing rotor in the figure, the dotted arrows in the figure show the flow direction of the axial magnetic circuit, and the solid arrows in the figure show the flow direction of the radial magnetic circuit;

[0017] Figure 3 for Figure 1 A schematic diagram of the three-dimensional structure of the first axial stator assembly or the second axial stator assembly.

[0018] The reference numerals indicate:

[0019] 1. Bearing rotor; 10. Rotating shaft; 21. Radial stator; 211. Middle pole; 212. First side pole; 213. Second side pole; 214. Stator yoke; 31. First axial stator; 311. First inner magnetic ring; 312. First axial pole; 41. Second axial stator; 411. Second inner magnetic ring; 412. Second axial pole; 51. Axial coil; 52. Radial coil; 001. Axial magnetic circuit; 002. Radial magnetic circuit; 003. Radial working gap; 004. First axial inner working gap; 005. Second axial inner working gap. DETAILED DESCRIPTION

[0020] See also Figures 1 to 3As shown, a magnetically suspended active three-degree-of-freedom bearing is provided, comprising a bearing rotor 1 for fixedly sleeved with a rotating shaft 10, a radial stator assembly sleeved on the radial outer side of the bearing rotor 1, and a first axial stator assembly and a second axial stator assembly respectively located at both axial ends of the bearing rotor 1, wherein the first axial stator assembly and the second axial stator assembly respectively form an axial magnetic circuit 001 with the bearing rotor 1 and the radial stator assembly to adjust the axial position of the bearing rotor 1, and a radial magnetic circuit 002 is formed between the radial stator assembly and the bearing rotor 1 to adjust the radial position of the bearing rotor 1, the radial stator assembly comprises a radial stator 21, and the radial stator 21 comprises a stator yoke 214, the inner ring of the stator yoke 214 has 16 poles extending toward one side of the bearing rotor 1, and in the axial projection of the rotating shaft 10, the 16 poles are centrally symmetrical about the center of the rotating shaft 10 and are distributed in four quadrants, and the four poles in each quadrant have two middle poles 211 and The first side pole 212 and the second side pole 213 on both sides of the middle pole 211 are symmetrical about the angular bisector of the corresponding quadrant. In the same quadrant, the polarities formed by the first side pole 212 and the adjacent middle pole 211, the two middle poles 211, and the second side pole 213 and the corresponding middle pole 211 are opposite. 11. The four second side poles 213 form a └┴┴┘-shaped structure. Both the first axial stator assembly and the second axial stator assembly have six axial poles spaced apart around the rotating shaft 10. An axial coil 51 is wound around each axial pole. The first side pole 212 and the second side pole 213 adjacent to each other in two adjacent quadrants form a side pole group. The six axial poles correspond one-to-one to the four side pole groups and the poles with the same polarity in the eight middle poles 211. It can be understood that the aforementioned four quadrants specifically refer to the center of the rotating shaft 10 as the coordinate origin O, and an orthogonal coordinate system XOY is established through the O point. The orthogonal coordinate system XOY divides the aforementioned axial projection into four adjacent quadrants. This aspect is basic geometric knowledge and will not be elaborated on. In this technical solution, the bearing rotor serves as a conducting component of the axial magnetic circuit 001 and the radial magnetic circuit 002 at the same time, integrating the thrust plate and the bearing rotor in the prior art into one, further improving the degree of integration of the bearing. There is no need to assemble the thrust plate separately on the rotating shaft 10, and the overall structure and processing technology are simplified, making it easier to assemble. The degree of integration is high, the structure is more compact, and the volume of the bearing is effectively reduced, the length of the rotating shaft is shortened, the critical speed of the rotor is increased, and the operating stability of the magnetic levitation system is improved.It should be noted that the axial stator of the present invention utilizes spaced poles. These poles enhance the magnetic flux at the radial working gap 003 corresponding to the corresponding intermediate pole 211 or first side pole 212 and second side pole 213 (i.e., the aforementioned side pole group). Furthermore, compared to a full-circle axial bearing outer ring, the six spaced axial poles in the axial stator assembly prevent radial magnetic flux from looping through the axial bearing outer ring, thereby preventing radial magnetic flux from flowing into the radial bearing rotor and thus preventing radial magnetic flux from forming a radial attractive force. Radial magnetic flux that does not contribute to radial attractive force is defined as "leakage flux," and therefore, the provision of axial poles here can prevent this "leakage flux" phenomenon.

[0021] Specific combination Figure 2 As shown, the aforementioned four quadrants are the first quadrant on the upper right, the second quadrant on the upper left, the third quadrant on the lower left, and the fourth quadrant on the lower right. Taking the four poles in the first quadrant as an example, the power-on direction of each radial coil 52 shown in the figure is the standard, wherein the free end of the upper left middle pole 211 presents an S pole, the free end of the lower right middle pole 211 presents an N pole, the free end of the first side pole 212 presents an N pole, and the second side pole 213 presents an S pole. In the first side pole 212 and the lower right middle pole 211, the flow direction of the radial magnetic circuit 002 is the same as the flow direction of the axial magnetic circuit 001, so that the magnetic flux between the first side pole 212 and the lower right middle pole 211 and the bearing rotor 1 can be increased, thereby increasing the radial force at the two places. It should be noted that the above content is aimed at the influence of axial magnetic flux on the pole in one quadrant, and the enhancement of radial magnetic flux by axial magnetic flux in the four quadrants offsets each other. That is, although the radial magnetic circuit and axial magnetic circuit of the integrated magnetic bearing both flow through the bearing rotor 1, the change of the axial magnetic circuit will not affect the overall radial magnetic circuit, which simplifies the control of the magnetic bearing.

[0022] In some embodiments, the circumferential width of the middle pole 211 is greater than the circumferential width of the first side pole 212 or the second side pole 213. Figure 2As shown, the middle pole 211 also serves as a flow path for the magnetic flux within the first side pole 212 and the second side pole 213. The circumferential width of the middle pole 211 is designed to be larger than the circumferential width of the two adjacent poles, which can optimize the magnetic circuits on both sides. In a preferred embodiment, the circumferential width of the middle pole 211 is twice the circumferential width of the first side pole 212 or the second side pole 213. In this way, the magnetic pole area of ​​the middle pole 211 is twice that of the two end poles, namely the first side pole 212 and the second side pole 213. At the same time, the middle pole 211 is connected in series with the first side pole 212 or the second side pole 213 to ensure that the radial control number of turns and the radial current are consistent, so that only one current needs to be adjusted to control the radial movement. This simple control method ensures that the radial magnetic flux of the middle pole 211 is twice that of the two end poles, the radial flux density on the three poles is consistent, and the magnetic circuit is not easily saturated.

[0023] Each pole is wound with a radial coil 52. The radial coil 52 wound on the first side pole 212 is connected in series with the radial coil 52 wound on the second side pole 213. The radial coils 52 wound on the two middle poles 211 are connected in series. Figure 2 As shown, in the first quadrant, the current flow direction of the radial coils 52 corresponding to the upper left first side pole 212 and the lower right middle pole 211 is left-in and right-out, while the current flow direction of the radial coils 52 corresponding to the upper left middle pole 211 and the lower right second side pole 213 is right-in and left-out. This achieves that the clockwise magnetic poles of the four poles in the first quadrant are NSNS. Of course, the current flow direction can be exactly the opposite so that the clockwise magnetic poles of the four poles in the first quadrant are SNSN. It should be noted that the polarity of the poles in the other quadrants must meet the requirement of centrosymmetry about the center of the rotating shaft 10. In this technical solution, by connecting the radial coils 52 of the first side pole 212 and the second side pole 213 in series, and connecting the radial coils 52 of the two middle poles 211 in series, the magnetic forces presented by the two poles are completely consistent, facilitating the adjustment and control of the radial position.

[0024] In some embodiments, the first axial stator assembly includes a first axial stator 31, the first axial stator 31 having a first inner magnetic ring 311 and a first axial pole 312, and the axial coil 51 is located between the first inner magnetic ring 311 and the first axial pole 312, wherein a first axial inner working gap 004 is formed between the first inner magnetic ring 311 and the left end face of the bearing rotor 1, a first axial outer working gap is formed between the first axial pole 312 and the left end face of the radial stator 21, and the first axial pole 312 is located radially inside the radial coil 52. Similarly, the second axial stator assembly includes a second axial stator 41, which has a second inner magnetic ring 411 and a second axial pole 412. The axial coil 51 is located between the second inner magnetic ring 411 and the second axial pole 412. A second axial inner working gap 005 is formed between the second inner magnetic ring 411 and the right end surface of the bearing rotor 1, and a second axial outer working gap is formed between the second axial pole 412 and the right end surface of the radial stator 21. The second axial pole 412 is located radially inward of the radial coil 52. In this technical solution, the first axial pole 312 or the second axial pole 412 is arranged corresponding to the pole position of the radial stator 21 and is located inward of the radial coil 52, rather than corresponding to the stator yoke 214 of the radial stator 21. This can reduce the leakage of magnetic flux in the radial magnetic circuit 002 in the axial direction and prevent the occurrence of circumferential unevenness in the axial output.

[0025] In some embodiments, the control of the radial coils 52 wound on the middle pole 211 in each quadrant is independent of the control of the radial coils 52 wound on the first side pole 212 and the second side pole 213. Specifically, Figure 2 As shown, the radial stator assembly has 16 magnetic poles (specifically, the aforementioned poles), which are four symmetrically distributed └┴┴┘-shaped structures, with small teeth at both ends (i.e., the aforementioned first side pole 212 and the second side pole 213, the same below), and a large tooth in the middle (i.e., the aforementioned middle pole 211, the same below). Each └┴┴┘-shaped structure pole is distributed in NSNS (or SNSN) in space. The radial magnetic circuit 002 is as shown in FIG. Figure 2As shown by the solid line, the first radial magnetic circuit on the └┴┴┘-shaped structure passes through the radial small tooth a (for example, the first side pole 212 on the upper left in the first quadrant, the same below) - radial working gap 003 - bearing rotor 1 - radial working gap 003 - radial large tooth b (for example, the middle pole 211 on the upper left in the first quadrant, the same below) - stator yoke 214 to the radial small tooth a and is closed; the second radial magnetic circuit passes through the radial large tooth c (for example, the middle pole 211 on the lower right in the first quadrant, the same below) - radial working gap 003 - bearing rotor 1 - radial working gap 003 - radial large tooth b - stator yoke 214 to the radial large tooth c and is closed; the third radial magnetic circuit passes through the radial large tooth c - radial working gap 003 - bearing rotor 1 - radial working gap 003 - radial small tooth d (for example, the second side pole 213 on the lower right in the first quadrant, the same below) - stator yoke 214 to the radial large tooth c and is closed. The axial magnetic circuit 001 is as shown in FIG. Figure 2 As shown by the dotted lines, all points point toward the center of the circle, strengthening the magnetic field in the air gaps of the radial small teeth a and radial large teeth c in the └┴┴┘-shaped structure. Conversely, when the axial magnetic circuit is oriented entirely toward the circumference, the magnetic field in the air gaps of the radial small teeth a and radial large teeth c in the └┴┴┘-shaped structure weakens. To control the bearing rotor's movement toward the upper left, the upper left radial winding is energized to provide a radial force to the upper left. To control the bearing rotor's movement upward, the upper left and right radial windings are energized to provide an upward radial force. This method provides a wide range of radial movement and flexible control.

[0026] In some embodiments, the current flowing through the axial coil 51 in the first axial stator assembly is opposite to the current flowing through the axial coil 51 in the second axial stator assembly, so as to ensure that the radial magnetic circuit 001 generated by the axial stator assemblies at both ends has an enhanced effect on the radial magnetic circuit 002 (i.e., a positive effect), thereby facilitating the control of the bearing rotor 1 to adjust the axial position of the bearing rotor 1.

[0027] Axial magnetic circuit 001 can be found in detail Figure 1 As shown, the axial pole of the axial stator is located at the lower end of the radial coil 52 ( Figure 1The inner magnetic ring of the axial stator is located at both ends of the bearing rotor 1. The axial magnetic circuit 001 generated by the axial coil 51 includes a first axial magnetic circuit and a second axial magnetic circuit, which are used to control the axial movement of the bearing rotor. The first axial magnetic circuit passes through the first axial pole 312-pole-radial working gap 003-bearing rotor 1-first axial inner working gap 004-first inner magnetic ring 311 and returns to the first axial stator 31 to close in a clockwise direction. The second axial magnetic circuit passes through the second axial pole 412-pole-radial working gap 003-bearing rotor 1-second axial inner working gap 005-the second inner magnetic ring 411 returns to the second axial stator 41 and closes counterclockwise. When the bearing rotor 1 needs to be controlled to move to the left, the current of the left bearing winding (that is, the axial coil 51 on the left) is increased, and the bearing rotor 1 is subjected to a greater force to the left. Conversely, when the bearing rotor 1 needs to be controlled to move to the right, the current of the right bearing winding (that is, the axial coil 51 on the right) is increased, and the bearing rotor 1 is subjected to a greater force to the right. Therefore, the axial movement of the bearing rotor 1 is controlled by controlling the current size of the left second axial winding.

[0028] It should be noted that the bearing of the present invention is an active electromagnetic bearing and does not have a permanent magnet to provide a bias magnetic field, so that the bearing of the present invention has the advantages of low cost, easy assembly, large load capacity, and high-power operation.

[0029] According to an embodiment of the present invention, a compressor is further provided, comprising the above-mentioned magnetically suspended active three-degree-of-freedom bearing.

[0030] According to an embodiment of the present invention, there is further provided a motor comprising the above-mentioned magnetically suspended active three-degree-of-freedom bearing.

[0031] It is easy for those skilled in the art to understand that, under the premise of no conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0032] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention. The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art may make various improvements and variations without departing from the technical principles of the present invention, and such improvements and variations shall also be considered within the scope of protection of the present invention.

Claims

1. A magnetically suspended active three-degree-of-freedom bearing, characterized in that: The invention relates to a bearing rotor (1) for fixedly sleeved with a rotating shaft (10), a radial stator assembly sleeved on the radial outer side of the bearing rotor (1), and a first axial stator assembly and a second axial stator assembly respectively located at two axial ends of the bearing rotor (1), wherein the first axial stator assembly and the second axial stator assembly respectively form an axial magnetic circuit (001) with the bearing rotor (1) and the radial stator assembly to adjust the axial position of the bearing rotor (1), and a radial magnetic circuit (002) is formed between the radial stator assembly and the bearing rotor (1) to adjust the radial position of the bearing rotor (1), and the radial stator assembly includes a radial stator (21), wherein the radial stator (21) has 16 poles extending toward one side of the bearing rotor (1), and in the axial projection of the rotating shaft (10), the 16 poles are centrally symmetrical about the center of the rotating shaft (10) and distributed in four quadrants, each of the quadrants having two intermediate poles (211) and two intermediate poles (212). The first side pole (212) and the second side pole (213) on both sides of the middle pole (211), the first side pole (212), the second side pole (213) and the two middle poles (211) are all symmetrical about the angular bisector of the corresponding quadrant, and in the same quadrant, the first side pole (212) and the middle pole (211) adjacent thereto, the two middle poles (211), the second side pole (213) and the middle pole (211) corresponding thereto are respectively symmetrical. The polarities of the first axial stator assembly and the second axial stator assembly are opposite, and each of the first axial stator assembly and the second axial stator assembly has six axial poles arranged at intervals around the rotating shaft (10), and an axial coil (51) is wound around each axial pole. The first side pole (212) and the second side pole (213) arranged adjacent to each other in two adjacent quadrants form a side pole group, and the six axial poles correspond one-to-one to the poles with the same polarity in the four side pole groups and the eight middle poles (211).

2. The magnetically suspended active three-degree-of-freedom bearing according to claim 1, characterized in that: The circumferential width of the middle pole (211) is greater than the circumferential width of the first side pole (212) or the second side pole (213).

3. The magnetically suspended active three-degree-of-freedom bearing according to claim 2, characterized in that: The circumferential width of the middle pole (211) is twice the circumferential width of the first side pole (212) or the second side pole (213).

4. The magnetically suspended active three-degree-of-freedom bearing according to any one of claims 1 to 3, characterized in that: A radial coil (52) is wound around each pole, the radial coil (52) wound around the first side pole (212) and the radial coil (52) wound around the second side pole (213) are connected in series, and the radial coils (52) wound around the two middle poles (211) are connected in series.

5. The magnetically suspended active three-degree-of-freedom bearing according to claim 4, characterized in that: The first axial stator assembly comprises a first axial stator (31), the first axial stator (31) having a first inner magnetic ring (311) and a first axial pole (312), the axial coil (51) being wound around each of the first axial poles (312), wherein a first axial inner working gap (004) is formed between the first inner magnetic ring (311) and the left end face of the bearing rotor (1), a first axial outer working gap is formed between the first axial pole (312) and the left end face of the radial stator (21), and the first axial pole (312) is located radially inside the radial coil (52).

6. The magnetically suspended active three-degree-of-freedom bearing according to claim 4, characterized in that: The second axial stator assembly includes a second axial stator (41), the second axial stator (41) having a second inner magnetic ring (411) and a second axial pole (412), the axial coil (51) being respectively wound around each of the second axial poles (412), wherein a second axial inner working gap (005) is formed between the second inner magnetic ring (411) and the right end face of the bearing rotor (1), a second axial outer working gap is formed between the second axial pole (412) and the right end face of the radial stator (21), and the second axial pole (412) is located radially inside the radial coil (52).

7. The magnetically suspended active three-degree-of-freedom bearing according to claim 4, characterized in that: The control of the radial coil (52) wound on the middle pole (211) in each quadrant is independent of the control of the radial coil (52) wound on the first side pole (212) and the second side pole (213).

8. The magnetically suspended active three-degree-of-freedom bearing according to claim 1, characterized in that: The current flowing through the axial coil (51) in the first axial stator assembly is opposite to the current flowing through the axial coil (51) in the second axial stator assembly.

9. A compressor, characterized in that: The invention comprises the magnetically suspended active three-degree-of-freedom bearing according to any one of claims 1 to 8.

10. A motor, characterized in that: The invention comprises the magnetically suspended active three-degree-of-freedom bearing according to any one of claims 1 to 8.

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