CN115355251A

CN115355251A - Axial magnetic bearing, magnetic suspension motor and magnetic suspension vacuum pump

Info

Publication number: CN115355251A
Application number: CN202211276198.7A
Authority: CN
Inventors: 李永胜; 赵明师; 朱永新; 张海刚; 刘仲; 刘力福; 王增鑫; 李致宇
Original assignee: Shandong Tianrui Heavy Industry Co Ltd
Current assignee: Shandong Tianrui Heavy Industry Co Ltd
Priority date: 2022-10-19
Filing date: 2022-10-19
Publication date: 2022-11-18

Abstract

The axial magnetic bearing comprises two stator components and a rotor component, wherein the two stator components respectively comprise a stator core and a winding wound on the stator core; the rotor assembly comprises a rotor body and a thrust component, and the thrust component is fixedly arranged on the rotor body; the two stator cores are respectively sleeved on the rotor main body, and the thrust component is positioned between the two stator cores; the thrust component and the two stator cores form an occlusion structure respectively; in a working state, the rotor main body and the two stator cores form axial first air gaps respectively; the thrust component and the two stator cores form a radial second air gap at the occlusion structure respectively. According to the axial magnetic bearing, the meshing structure is formed between the stator assembly and the thrust component, so that the contact area of the magnetic poles between the thrust component and the stator assembly is increased, and the bearing capacity and the rigidity of the axial magnetic bearing are increased.

Description

Axial magnetic bearing, magnetic suspension motor and magnetic suspension vacuum pump

Technical Field

The disclosure relates to the technical field of magnetic bearings, in particular to an axial magnetic bearing, a magnetic suspension motor and a magnetic suspension vacuum pump.

Background

In the process that the magnetic suspension vacuum pump applies work to gas through the centrifugal principle to obtain a vacuum state, air pressure at the back of an impeller wheel of the magnetic suspension vacuum pump and a vacuum preparation position at the front side of the impeller can generate air pressure difference, the air pressure difference can form larger axial force, and the axial force acts on the back of the impeller wheel. Along with the vacuum degree of a vacuum preparation place (namely the front side of the impeller) of the vacuum pump is larger, the air pressure difference between the back of the impeller and the front side of the impeller is larger, the axial force acting on the back of the impeller is larger, and potential safety hazards are brought to the stability and the reliability of the whole magnetic suspension vacuum pump.

Disclosure of Invention

To overcome the problems in the related art, the present disclosure provides an axial magnetic bearing, a magnetic levitation motor, and a magnetic levitation vacuum pump.

The present disclosure proposes, in a first aspect, an axial magnetic bearing comprising:

the two stator assemblies are arranged on the stator core, and each stator assembly comprises a stator core and a winding wound on the stator core;

the rotor assembly comprises a rotor body and a thrust part, and the thrust part is fixedly arranged on the rotor body; the two stator cores are respectively sleeved on the rotor main body, and the thrust component is positioned between the two stator cores; the thrust component is connected with the two stator cores through meshing structures respectively;

in a working state, first axial air gaps are respectively formed between the rotor main body and the two stator cores; the thrust component and the two stator cores form a radial second air gap at the meshing structure respectively.

In an exemplary embodiment, a cavity is formed between the thrust member and the stator core;

the stator core is provided with a through hole which is communicated with the cavity and the outside; the bite structure prevents external gas from entering the cavity from the second air gap.

In an exemplary embodiment, the thrust member includes a thrust disk, the thrust disk being located between two of the stator cores;

the cavity and the meshing structure are arranged between the stator core and the thrust disc.

In an exemplary embodiment, the thrust member includes a shaft sleeve, the thrust disc is disposed on an outer circumferential wall of the shaft sleeve, the shaft sleeve is coaxially sleeved on the rotor body, and the shaft sleeve is in interference fit with the rotor body.

In an exemplary embodiment, the stator core includes an inner ring and an outer ring, a side of the inner ring close to the thrust disc is provided with a first inner magnetic pole, a side of the outer ring close to the thrust disc is provided with a first outer magnetic pole, and the winding is wound between the first inner magnetic pole and the first outer magnetic pole; the positions of the thrust disc corresponding to the first inner magnetic pole and the first outer magnetic pole are respectively set as a second inner magnetic pole and a second outer magnetic pole;

the meshing structure comprises first teeth arranged on the first inner magnetic pole and the first outer magnetic pole and second teeth arranged on the second inner magnetic pole and the second outer magnetic pole; the first tooth part is meshed with the second tooth part;

in a working state, the first air gap is positioned between the rotor main body and the inner ring of the stator core; the second air gap is located between the first tooth and the second tooth.

In an exemplary embodiment, the first tooth portion includes a plurality of first annular teeth arranged in a radial direction of the stator core, each of the first annular teeth encircling or extending in a circumferential direction of the stator core;

and/or the second tooth portion comprises a plurality of second annular teeth, the plurality of second annular teeth are arranged along the radial direction of the thrust disc, and each second annular tooth surrounds or extends along the axial direction of the thrust disc;

the plurality of first annular teeth and the plurality of second annular teeth are arranged in a staggered mode.

In an exemplary embodiment, a plane parallel to the axis of the rotor body is taken as a preset cross section, and a projection of the second air gap on the preset cross section is in a zigzag shape.

In an exemplary embodiment, the second air gap has a dimension of 0.4mm to 0.6mm in an axial direction of the rotor body;

and/or the presence of a gas in the atmosphere,

the second air gap has a size of 0.2mm to 0.4mm in a radial direction of the rotor body.

A second aspect of the present disclosure proposes a magnetic levitation electric machine comprising the axial magnetic bearing proposed by the first aspect of the present disclosure.

A magnetic levitation vacuum pump of a third aspect of the present disclosure comprises a vacuum pump diffuser and the magnetic levitation motor of the second aspect of the present disclosure;

and a vacuum chamber is arranged in the vacuum pump diffuser, the vacuum chamber is communicated with a cavity of the magnetic suspension motor, which is far away from the vacuum pump diffuser, and the cavity is positioned between the stator assembly and the thrust component.

The technical scheme provided by the embodiment of the disclosure can have the following beneficial effects: according to the axial magnetic bearing, the meshing structure is arranged between the stator core and the thrust component, so that the contact area of the magnetic poles between the thrust component and the stator core is increased, the bearing capacity and rigidity of the axial magnetic bearing are increased, and the stability and reliability of the whole machine are improved. Meanwhile, a second air gap is formed between the thrust component and the stator iron core, the rotation of the thrust component relative to the stator iron core is realized, the engagement structure prevents external air from entering a cavity between the stator iron core and the thrust disc from the second air gap, in the application scene of the magnetic suspension vacuum pump, two cavities between the two stator iron cores and the thrust disc are respectively communicated with the atmosphere and a vacuum cavity of the vacuum pump, axial force generated by air pressure difference of the two cavities counteracts axial force generated at an impeller of the vacuum pump, and the axial force generated by the air pressure difference of the two cavities changes along with the change of the vacuum degree, so that the self-adaptive adjustment function of the axial magnetic bearing is realized. Meanwhile, the position of the rotor body is adjusted by superposing the axial force generated by the air pressure difference of the two cavities and the axial force generated by the axial magnetic bearing, so that the rotor body is always in a balanced state, and the damage of the instability of the rotor body to the magnetic bearing is avoided.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

FIG. 1 is a cross-sectional view of an axial magnetic bearing shown in accordance with an exemplary embodiment.

Fig. 2 is an enlarged view at a in fig. 1.

Fig. 3 is a schematic view of a stator core shown in accordance with an exemplary embodiment.

Fig. 4 is a cross-sectional view of a stator core shown in accordance with an exemplary embodiment.

FIG. 5 is a schematic view of a thrust member shown in accordance with an exemplary embodiment.

FIG. 6 is a cross-sectional view of a thrust member shown in accordance with an exemplary embodiment.

Fig. 7 is an assembled perspective view of a thrust member and stator assembly shown in accordance with an exemplary embodiment.

FIG. 8 is an assembled cross-sectional view of a thrust member and stator assembly shown in accordance with an exemplary embodiment.

FIG. 9 is a cross-sectional view of a vacuum pump shown in accordance with an exemplary embodiment.

Wherein: 1-a stator assembly; 11-a stator core; 12-a winding; 2-a rotor assembly; 21-a rotor body; 22-a thrust member; 221-a thrust disc; 222-a shaft sleeve; 3-a cavity; 4-an occlusion structure; 5-a second air gap; 6-a first air gap; 111-outer loop; 112-inner ring; 1111-a first outer pole; 1121-a first inner magnetic pole; 113-a via; 114-a first tooth; 2211-a second outer magnetic pole; 2212-second inner magnetic pole; 223-second tooth; 7-vacuum pump diffuser; 71-a vacuum chamber; 72-a bellows; 73-a vacuum pump impeller; 74-vacuum pump volute; 8-a switching disk; 9-motor housing; 10-left axial magnetic bearing mount.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary examples do not represent all implementations consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the invention, as detailed in the appended claims.

In the process that the magnetic suspension vacuum pump works on gas to obtain a vacuum state through a centrifugal principle, air pressure difference is generated between the air pressure at the back of an impeller wheel of the magnetic suspension vacuum pump and a vacuum preparation position at the front side of the impeller, the air pressure difference can form large axial force, and the axial force acts on the back of the impeller wheel. Along with the vacuum degree of a vacuum preparation place (namely the front side of the impeller) of the vacuum pump is larger, the air pressure difference between the back of the impeller and the front side of the impeller is larger, the axial force acting on the back of the impeller is larger, and potential safety hazards are brought to the stability and the reliability of the whole magnetic suspension vacuum pump.

In order to solve the above technical problems, the present disclosure provides an axial magnetic bearing, which includes a rotor assembly and two stator assemblies, each stator assembly including a stator core and a winding wound on the stator core; the rotor assembly comprises a rotor main body and a thrust component, the thrust component is located between the two stator cores, the thrust component and the two stator cores form an occlusion structure respectively, and in a working state, the thrust component and the two stator assemblies form a radial second air gap at the occlusion structure respectively.

According to the axial magnetic bearing, the meshing structure is arranged between the stator core and the thrust component, so that the contact area of the magnetic poles between the thrust component and the stator core is increased, the bearing capacity and rigidity of the axial magnetic bearing are increased, and the stability and reliability of the whole machine are improved.

According to an exemplary embodiment of the present disclosure, as shown in fig. 1-2, 7-8, the axial magnetic bearing of the present embodiment includes two stator assemblies 1, and the two stator assemblies 1 are oppositely disposed. Each stator assembly 1 includes a stator core 11 and a winding 12 wound around the stator core 11. The axial magnetic bearing of this embodiment further includes a rotor assembly 2, wherein the rotor assembly 2 includes a rotor body 21 and a thrust member 22, the thrust member 22 is fixedly disposed on the rotor body 21, the two stator cores 11 are respectively sleeved on the rotor body 21, and the stator cores 11 are disposed coaxially with the rotor body 21. The thrust member 22 is located between the two stator cores 11, the thrust member 22 transmits the axial thrust of the rotor body 21 in the rotating state to the stator cores 11, and the thrust member 22 simultaneously provides a force application point for the axial force generated by the stator cores 11. The rotor body 21 can rotate relative to the stator core 11, the rotor body 21 rotates to drive the thrust member 22 to rotate, and the thrust member 22 can rotate relative to the stator core 11. The thrust components 22 are respectively connected with the two stator cores 11 through the meshing structure 4, and in an operating state, the rotor body 21 and the two stator cores 11 respectively form axial first air gaps 6 so as to realize non-contact rotation of the rotor body 21 relative to the stator cores 11. The thrust member 22 and the two stator cores 11 form a second radial air gap 5 at the engagement structure 4, respectively, to achieve a contactless rotation between the thrust member 22 and the stator cores 11.

In the embodiment, the engagement structure 4 is arranged, so that the contact area of the magnetic poles between the thrust component 22 and the stator component 1 is increased, the bearing capacity and the rigidity of the magnetic bearing are increased, and the stability and the reliability of the whole machine are improved.

According to an exemplary embodiment of the present disclosure, as shown in fig. 1 and fig. 2, the present embodiment proposes an axial magnetic bearing, in which a meshing structure 4 is formed between a thrust member 22 and two stator cores 11, and in an operating state, the thrust member 22 and the stator cores 11 form a second radial air gap 5 at the meshing structure 4.

A cavity 3 is formed between the thrust component 22 and the stator core 11, a through hole 113 is formed in the stator core 11, the through hole 113 is communicated with the cavity 3 and the outside, and the meshing structure 4 prevents outside air from entering the cavity 3 from the second air gap 5.

In the embodiment, the through holes are arranged to realize the airflow conduction between the cavity and the external environment, and the engagement structure prevents external air from entering the cavity between the stator core and the thrust disc through the second air gap, so that the self-adaptive adjustment of the magnetic bearing is realized. In the application scene of the magnetic suspension vacuum pump, one cavity between the two stator cores and the thrust disc is communicated with the atmosphere, the other cavity is communicated with the vacuum cavity of the vacuum pump, the axial force generated by the air pressure difference between the two cavities counteracts the axial force generated at the impeller of the vacuum pump, and the axial force generated by the air pressure difference between the two cavities changes along with the change of the vacuum degree, so that the self-adaptive adjustment function of the axial magnetic bearing is realized. Meanwhile, the position of the rotor body is adjusted by superposing the axial force generated by the air pressure difference of the two cavities and the axial force generated by the axial magnetic bearing, so that the rotor body is always in a balanced state, and the damage of the instability of the rotor body to the magnetic bearing is avoided.

According to an exemplary embodiment, as shown in fig. 1, 5 and 6, the present embodiment includes all the above, except that the thrust member 22 of the present embodiment includes a thrust disk 221, the thrust disk 221 has a disk shape, and the disk-shaped thrust disk 221 is annularly disposed on the outer circumferential wall of the rotor body 21 and between the two stator cores 11. The cavity 3 and the meshing structure 4 are both arranged between the stator core 11 and the thrust disc 221. In this embodiment, the material of the stator core 11 and the thrust plate 221 is not limited, and in an example, the stator core 11 and the thrust plate 221 are made of a high saturation magnetic density iron-cobalt-vanadium soft magnetic alloy material or an electrical pure iron material.

The present embodiment provides a point of application for the axial force generated by the stator core while transmitting the axial thrust of the rotor to the stator core by disposing the thrust disk between the two stator cores, so as to maintain the balance of the rotor body. The engagement structure is arranged between the stator core and the thrust disc, so that the contact area of the magnetic poles between the thrust disc and the stator core is increased, and the bearing capacity and the rigidity of the magnetic bearing are increased.

The thrust disk 221 of the present embodiment may be directly provided on the rotor main body 21, for example, the thrust disk 221 is fixedly provided on the rotor main body 21 by welding.

The thrust disk 221 of the present embodiment may also be provided independently of the rotor main body 21, and in an example, referring to fig. 1, 5 and 6, the thrust member 22 further includes a shaft sleeve 222, the thrust disk 221 is provided on an outer circumferential wall of the shaft sleeve 222, the shaft sleeve 222 is sleeved on the outside of the rotor main body 21, and the shaft sleeve 222 is coaxially provided with the rotor main body 21 and is in interference fit with the rotor main body 21. In the embodiment, the thrust disc 221 is fixed on the rotor body 21 through the shaft sleeve 222, so that the fixed connection between the rotor body 21 and the thrust disc 221 is realized, the assembly of the thrust disc 221 is facilitated, and the thrust disc 221 is also replaced conveniently under the condition that the thrust disc 221 is damaged.

According to an exemplary embodiment of the present disclosure, as shown in fig. 2 to 8, the present embodiment includes all the contents of the above embodiments except that the stator core 11 includes an inner ring 112 and an outer ring 111, a side of the inner ring 112 close to the thrust disk 221 is provided as a first inner magnetic pole 1121, a side of the outer ring 111 close to the thrust disk 221 is provided as a first outer magnetic pole 1111, and the winding 12 is wound between the first inner magnetic pole 1121 and the first outer magnetic pole 1111; the positions of the thrust disc 221 corresponding to the first inner magnetic pole 1121 and the first outer magnetic pole 1111 are respectively set as a second inner magnetic pole 2212 and a second outer magnetic pole 2211;

the configuration of the engagement structure 4 can be varied, and in one example, referring to fig. 2-8, the engagement structure 4 includes a first tooth portion 114 disposed on the first inner magnetic pole 1121 and the first outer magnetic pole 1111, and a second tooth portion 223 disposed on the second inner magnetic pole 2212 and the second outer magnetic pole 2211, and the first tooth portion 114 is engaged with the second tooth portion 223. In the operating state, a first air gap 6 is formed between the rotor body 21 and the inner ring 112 of the stator core 11; a second air gap 5 is formed between the first tooth portion 114 and the second tooth portion 223, the second air gap 5 may be equivalent to an air gap between the thrust disk 221 and the stator core 11, and the second air gap 5 may also be a part of the air gap between the thrust disk 221 and the stator core 11.

The first tooth portion and the second tooth portion may have a saw-tooth shape or a convex shape

According to the embodiment, the first tooth part is arranged on the stator core, the second tooth part meshed with the first tooth part is arranged on the thrust disc, so that the relative contact area between the first inner magnetic pole of the stator core and the second inner magnetic pole of the thrust disc and the relative contact area between the first outer magnetic pole of the stator core and the second outer magnetic pole of the thrust disc are increased, the bearing capacity of the magnetic bearing is increased, and the rigidity of the magnetic bearing is improved.

According to an exemplary embodiment of the present disclosure, as shown in fig. 2 to 6, the present embodiment includes all of the above embodiments except that the first tooth portion 114 of the present embodiment includes a plurality of first ring-shaped teeth, which are arranged in a radial direction of the stator core 11, each of which surrounds or extends in a circumferential direction of the stator core 11. And/or the second tooth portion 223 comprises a plurality of second annular teeth, the plurality of second annular teeth are arranged along the radial direction of the thrust disc 221, each second annular tooth surrounds or extends along the axial direction of the thrust disc 221, and the plurality of first annular teeth and the plurality of second annular teeth are arranged in a staggered mode to form an annular labyrinth seal, so that the sealing effect of the meshing structure 4 on the cavity 3 is improved.

According to an exemplary embodiment of the present disclosure, as shown in fig. 2, the present embodiment includes all the above embodiments, except that a plane parallel to the axis of the rotor body 21 is a preset cross section, and a projection of the second air gap 5 on the preset cross section is in a zigzag shape. The axial direction of the rotor body 21 is shown in the direction of the X-axis in fig. 2.

The meshing structure that this embodiment formed through first tooth portion and the meshing of second tooth portion, outside air current can't enter into the cavity through second air gap, has guaranteed the airtight effect of meshing structure to the cavity.

According to an exemplary embodiment of the present disclosure, as shown in fig. 2, the second air gap 5 has a size of 0.4mm to 0.6mm in the axial direction of the rotor body 21; the second air gap 5 has, for example, a dimension of 0.5mm in the axial direction of the rotor body 21. And/or, in the radial direction of the rotor body 21, the dimension of the second air gap 5 is 0.2mm-0.4mm, for example, the dimension of the second air gap 5 in the radial direction of the rotor body 21 is 0.3mm. The axial direction of the rotor body 21 is shown by the X axis in fig. 2, and the radial direction of the rotor body 21 is shown by the Y axis in fig. 2.

In the embodiment, by limiting the width of the second air gap in the axial direction and the radial direction of the rotor body, external air can be prevented from entering a cavity between the stator core and the thrust disc while the non-contact rotation of the thrust disc relative to the stator core is ensured.

According to an exemplary embodiment of the present disclosure, the present embodiment proposes a magnetic levitation motor, which includes the axial magnetic bearing in the above embodiments. In an example, in a direction shown by an arrow in fig. 9, the magnetic levitation motor includes a motor housing 9 and a left axial magnetic bearing mounting base 10, the left axial magnetic bearing mounting base 10 is located on an axial left side of an inner cavity of the motor housing 9 and is fixedly mounted on the motor housing 9 through a screw fixing member, a stator assembly 1 located on the left side is fixedly mounted on a right end face of the left axial magnetic bearing mounting base 10 through a screw fixing member, and a stator assembly 1 located on the right side is located on an axial right side of the inner cavity of the motor housing 9 and is fixedly mounted on a left end face of the inner cavity of the motor housing 9 through a screw fixing member.

The magnetic suspension motor of the embodiment can realize self-adaptive adjustment of axial force in a working state so as to ensure the stability and reliability of the whole machine, and simultaneously can maintain the rotor spindle to be always in a balance position.

According to an exemplary embodiment of the present disclosure, as shown in fig. 9, the present embodiment proposes a magnetic levitation vacuum pump, which includes a vacuum pump diffuser 7 and the magnetic levitation motor proposed in the above embodiment. A vacuum chamber 71 is arranged in the vacuum pump diffuser 7, the vacuum chamber 71 is communicated with a cavity 3 of the magnetic suspension motor, which is far away from the vacuum pump diffuser, and the cavity 3 is positioned between the stator assembly 1 and the thrust component 22. In one example, the vacuum pump further includes a vacuum pump volute 74, an adapter disk 8, and a vacuum pump impeller 73, in a direction indicated by an arrow in fig. 9, the vacuum pump impeller 73 being located on the left end surface of the rotor body 21 in the axial direction and fixedly mounted on the rotor body 21 by fastening bolts. The vacuum pump diffuser 7 is located on the left side of the vacuum pump volute 74 in the axial direction, the vacuum pump diffuser 7 is fixed on the left end face of the vacuum pump volute 74 through a screw fixing piece, the adapter plate 8 is located on the right side of the vacuum pump volute 74 in the axial direction, the adapter plate 8 is fixedly connected with the right end face of the vacuum pump volute 74 through a screw fixing piece, and the adapter plate 8 is located between the motor housing 9 and the vacuum pump volute 74 and is fixedly installed on the motor housing 9 through screws. The vacuum chamber 71 and the cavity 3 on the right side are communicated with each other through a bellows 72, both ends of the bellows 72 are respectively attached to the vacuum pump diffuser 7 and the stator assembly 1 on the right side, and the vacuum chamber 71 in the vacuum pump diffuser 7 and the cavity 3 on the right side are communicated with each other.

In the process that the magnetic suspension vacuum pump works on gas to obtain a vacuum state through a centrifugal principle, air pressure at the back of an impeller wheel of the magnetic suspension vacuum pump and a vacuum preparation position at the front side of the impeller can generate air pressure difference, and large axial force formed by the air pressure difference acts on the back of the impeller wheel. As the degree of vacuum at the vacuum generating place (i.e., the front side of the impeller) of the vacuum pump is larger, the generated air pressure difference between the back of the impeller and the front side of the impeller is larger, and the axial force acting on the back of the impeller is larger. In the present embodiment, the engagement structure 4 is provided between the thrust member 22 and the two stator cores 11, and the engagement seal is formed for the cavity between the thrust member 22 and the stator cores 11, so as to prevent the external air flow from entering the cavity 3 through the second air gap 5 between the thrust member 22 and the stator cores 11, and by connecting the cavity 3 formed by the stator core 11 and the thrust member 22 on the left side with the outside, a pressure gradient is formed, in which the vacuum degree of the cavity 3 on the left side is equal to the atmospheric pressure on the outside. The cavity 3 formed by the stator core 11 and the thrust member 22 on the right side is communicated with the vacuum chamber 71 in the vacuum pump diffuser 7, and a pressure gradient is formed in which the vacuum degree of the cavity 3 on the right side is equal to the vacuum degree of the vacuum pump diffuser 7. During the working process, the left cavity 3 and the right cavity 3 form air pressure difference, and axial force formed by the air pressure difference of the two cavities 3 acts on the thrust disc 221 to counteract the axial force formed by the air pressure difference at the vacuum preparation position of the impeller wheel back and the impeller front side. The axial force generated by the air pressure difference of the two cavities 3 changes along with the change of the vacuum degree of the vacuum preparation part, and has a self-adaptive adjusting function. Meanwhile, the axial force generated by the air pressure difference of the two cavities 3 is superposed with the axial force generated by the axial magnetic bearing to adjust the position of the rotor body 21, so that the vacuum pump impeller 73 is always in a balanced state, and the rotor body 21 is prevented from being unstable to damage the magnetic bearing.

Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the embodiments disclosed herein. This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

It will be understood that the invention is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.

Claims

1. An axial magnetic bearing, comprising:

the stator assembly comprises two stator assemblies (1), wherein each stator assembly (1) comprises a stator core (11) and a winding (12) wound on the stator core (11);

the rotor assembly (2), the rotor assembly (2) includes the rotor body (21) and thrust part (22), the thrust part (22) is fixedly set up on the rotor body (21); the two stator cores (11) are respectively sleeved on the rotor main body (21), and the thrust component (22) is positioned between the two stator cores (11); the thrust component (22) is respectively connected with the two stator cores (11) through a meshing structure (4);

in the working state, first axial air gaps (6) are respectively formed between the rotor main body (21) and the two stator cores (11); the thrust component (22) and the two stator cores (11) form a second radial air gap (5) at the meshing structure (4).

2. The axial magnetic bearing according to claim 1, wherein a cavity (3) is formed between the thrust member (22) and the stator core (11);

a through hole (113) is formed in the stator core (11), and the through hole (113) is communicated with the cavity (3) and the outside; the bite structure (4) prevents external gas from entering the cavity (3) from the second air gap (5).

3. The axial magnetic bearing according to claim 2, wherein the thrust member (22) comprises a thrust disc (221), the thrust disc (221) being located between the two stator cores (11);

the cavity (3) and the meshing structure (4) are arranged between the stator core (11) and the thrust disc (221).

4. The axial magnetic bearing according to claim 3, wherein the thrust member (22) comprises a shaft sleeve (222), the thrust disk (221) is disposed on an outer peripheral wall of the shaft sleeve (222), the shaft sleeve (222) is fitted over the rotor body (21), and the shaft sleeve (222) is interference-fitted with the rotor body (21).

5. An axial magnetic bearing according to claim 3, characterized in that the stator core (11) comprises an inner ring (112) and an outer ring (111), the side of the inner ring (112) close to the thrust disc (221) is provided as a first inner pole (1121), the side of the outer ring (111) close to the thrust disc (221) is provided as a first outer pole (1111), the winding (12) is wound between the first inner pole (1121) and the first outer pole (1111); the positions of the thrust disc (221) corresponding to the first inner magnetic pole (1121) and the first outer magnetic pole (1111) are respectively arranged as a second inner magnetic pole (2212) and a second outer magnetic pole (2211);

the snap-in structure (4) comprises a first tooth (114) arranged on the first inner magnetic pole (1121) and the first outer magnetic pole (1111), and a second tooth (223) arranged on the second inner magnetic pole (2212) and the second outer magnetic pole (2211); the first tooth (114) meshes with the second tooth (223);

in the working state, the first air gap (6) is positioned between the rotor main body (21) and an inner ring (112) of the stator iron core (11); the second air gap (5) is located between the first tooth (114) and the second tooth (223).

6. The axial magnetic bearing according to claim 5, wherein the first tooth portion (114) comprises a plurality of first annular teeth arranged in a radial direction of the stator core (11), each of the first annular teeth surrounding or extending in a circumferential direction of the stator core (11);

and/or the second toothing (223) comprises a plurality of second annular teeth aligned in a radial direction of the thrust disc (221), each second annular tooth surrounding or extending in an axial direction of the thrust disc (221);

the first annular teeth and the second annular teeth are arranged in a staggered mode.

7. Axial magnetic bearing according to claim 5, characterized in that the projection of the second air gap (5) in a plane parallel to the axis of the rotor body (21) is zigzag-shaped in a predetermined cross section.

8. The axial magnetic bearing according to claim 7, wherein the second air gap (5) has a dimension of 0.4-0.6 mm in the axial direction of the rotor body (21);

and/or the presence of a gas in the gas,

the second air gap (5) has a dimension of 0.2mm to 0.4mm in a radial direction of the rotor body (21).

9. A magnetically levitated electric motor, characterized in that it comprises an axial magnetic bearing according to any one of claims 1-8.

10. A magnetic levitation vacuum pump, characterized in that it comprises a vacuum pump diffuser (7) and a magnetic levitation motor as claimed in claim 9;

a vacuum chamber (71) is arranged in the vacuum pump diffuser (7), the vacuum chamber (71) is communicated with a cavity (3) of the magnetic suspension motor, the cavity is far away from the vacuum pump diffuser, and the cavity (3) is located between the stator assembly (1) and the thrust component (22).