Axial magnetic flux magnetic suspension compressor

Abstract

An axial magnetic flux magnetic suspension compressor comprises a motor assembly, a rotor assembly, a magnetic suspension assembly and a shell. The magnetic suspension assembly is fixedly arranged in the shell, the rotor assembly is arranged on the inner side of the magnetic suspension assembly, and the magnetic suspension assembly is used for supporting the rotor assembly to achieve magnetic suspension. The motor assembly is arranged on the inner side wall of the shell and located on the outer side of the magnetic suspension assembly and used for pushing the rotor assembly to rotate. The rotor assembly comprises a rotor and a rotor disc, the rotor disc is fixedly arranged on the rotor in a sleeving mode, and the motor assembly acts on the rotor disc to push the rotor assembly to rotate. According to the deep integration structure of the axial magnetic bearing and the axial motor, the thrust disc controlled by the axial magnetic bearing is combined with the axial motor, the axial length is remarkably shortened, and the critical rotating speed is greatly increased.

Description

Technical Field

[0001] The present invention belongs to the technical field of compressors, and particularly relates to an axial flux magnetic levitation compressor. Background Art

[0002] Traditional compressors rely on mechanical bearings and gear speed increasing mechanisms to achieve rotor support and power transmission through physical contact and friction, which have technical limitations: their contact structure causes serious mechanical wear and requires a complex lubrication system to maintain operation, not only increasing maintenance costs but also posing a risk of leakage and pollution; the axial series layout results in a large equipment volume and limited critical speed, restricting high-speed performance; the passive vibration damping design is difficult to suppress operating vibrations, affecting stability and lifespan; gear transmission and friction losses significantly reduce energy efficiency, and the redundant mechanical structure further limits the power density.

[0003] In order to reduce friction, magnetic levitation compressors have emerged. Conventional magnetic levitation compressors adopt an axial series layout of radial magnetic levitation bearings and radial permanent magnet motors. The radial magnetic bearings are symmetrically distributed on both sides of the motor stator, and the axial magnetic bearing controls the rotor displacement through an independent thrust disk, resulting in redundant axial length of the rotor assembly and limited critical speed. This structure is restricted in applications in some scenarios with strict weight and size requirements (such as airborne equipment, aerospace).

[0004] In order to minimize the system weight and increase the rotor critical speed, air bearings are used in industry to support the rotor. Air bearings use the dynamic pressure effect formed in a small air gap after the rotor rotates to support the rotating shaft. Since the air bearings adopt a foil structure, their axial length is relatively small, enabling the system speed to reach higher than that of magnetic levitation bearings. However, air bearings have the following problems: 1. Low stiffness. Since the rotor suspension relies on the dynamic pressure effect of the air film and cannot actively, quickly, and accurately adjust the air pressure field, it is prone to instability when the load suddenly changes; 2. Lack of active control ability. Since the air supply method of the air bearing lacks closed-loop feedback, the dynamic response is poor, and it is difficult to suppress start-stop vibrations; 3. Limited applicable scenarios. Due to the limited strength of the passive air film support, it is only suitable for low-power scenarios, requires high cleanliness of the supporting air, high requirements for gas supply equipment, and high internal sealing conditions, and is not suitable for working in harsh environments.

[0005] On the path of integrating, optimizing, and reducing the weight of the magnetic levitation system, methods such as permanent magnet biasing, radial-axial hybrid magnetic levitation bearings, and rotor design without a thrust disk are also used. However, these are all structural optimizations for the magnetic levitation bearings themselves, and the radial motor is relatively heavy in the magnetic levitation compressor system. Therefore, the above optimization measures for the structure of the magnetic levitation bearings may have little effect on reducing the overall mass. Summary of the Invention

[0006] The object of the present invention is to provide an axial flux magnetic levitation compressor to solve the problem that the axial size of the magnetic levitation compressor in the prior art is large and it is difficult to adapt to scenarios with limited space.

[0007] To achieve the above object, the present invention adopts the following technical solutions: An axial flux magnetic levitation compressor includes a motor assembly, a rotor assembly, a magnetic levitation assembly and a housing; the magnetic levitation assembly is fixedly arranged inside the housing, the rotor assembly is arranged inside the magnetic levitation assembly, and the magnetic levitation assembly is used to support the rotor assembly to achieve magnetic levitation; the motor assembly is arranged on the inner side wall of the housing and outside the magnetic levitation assembly, and is used to drive the rotor assembly to rotate; the rotor assembly includes a rotor and a rotor disk, the rotor disk is fixedly sleeved on the rotor, and the motor assembly acts on the rotor disk to drive the rotor assembly to rotate.

[0008] Further, the rotor disk includes a thrust disk, a magnetic isolation disk and permanent magnets; the thrust disk is fixedly sleeved on the rotor, the magnetic isolation disk is an annular disk, the magnetic isolation disk is fixedly sleeved outside the thrust disk, and a plurality of permanent magnets are nested on the magnetic isolation disk.

[0009] Further, the magnetic isolation disk is made of non-magnetic conductive material.

[0010] Further, the permanent magnets are embedded on the magnetic isolation disk according to the Halbach array, and adjacent permanent magnets have opposite magnetic polarities.

[0011] Further, the thrust disk is a magnetic conductive material disk.

[0012] Further, the magnetic levitation assembly includes an axial magnetic levitation bearing and a radial magnetic levitation bearing. Two radial magnetic levitation bearings are symmetrically arranged inside the housing, two axial magnetic levitation bearings are arranged between the two radial magnetic levitation bearings, the rotor passes through and is arranged inside the axial magnetic levitation bearing and the radial magnetic levitation bearing, and the rotor disk is located between the two axial magnetic levitation bearings.

[0013] Further, the motor assembly includes a motor stator and a motor coil, and the motor coil is wound on the motor stator; the motor assembly is arranged outside the two axial magnetic levitation bearings and is isolated by magnetic isolation material.

[0014] Further, the thrust disk of the rotor disk is located between the two axial magnetic levitation bearings, and the permanent magnets of the rotor disk are located between the motor assemblies.

[0015] Further, two protection bearings are symmetrically arranged on the housing, and the rotor is arranged between the two protection bearings.

[0016] Further, the rotor is connected with two-stage impellers and a volute on the outside of the housing.

[0017] Compared with the prior art, the present invention has the following technical effects: The present invention proposes a deep integration architecture of an axial magnetic levitation bearing and an axial motor. By combining the thrust disk controlled by the axial magnetic bearing with the axial motor, the axial length is significantly shortened, and the critical speed is greatly increased. While reducing the volume and weight, it also takes into account high speed, high stability, and energy efficiency optimization, providing solutions for space - demanding scenarios such as aviation and vehicle applications. Brief Description of the Drawings

[0018] Figure 1 It is a schematic structural diagram of the present invention.

[0019] Figure 2 It is a schematic structural diagram of the rotor disk of the present invention.

[0020] Wherein: 1. Motor coil; 2. Motor stator; 3. Axial magnetic levitation bearing coil; 4. Protection bearing; 5. Second - stage volute; 6. Second - stage impeller; 7. Rotor; 8. Bearing magnetic levitation bearing stator; 9. Rotor disk; 10. Magnetic isolation ring; 11. Radial magnetic levitation bearing stator; 12. Radial magnetic levitation bearing coil; 13. First - stage impeller; 14. First - stage volute; 15. Axial thrust disk; 16. Permanent magnet; 17. Magnetic isolation disk. Detailed Embodiments

[0021] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0022] In the description of the present invention, it should be noted that terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating orientation or positional relationships are based on the orientation or positional relationships shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, terms such as "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0023] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, terms such as "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0024] Embodiment 1. Please refer to Figure 1 , the present invention provides an axial flux magnetic levitation compressor, which includes a motor assembly, a rotor assembly, a magnetic levitation assembly, and a housing; the magnetic levitation assembly is fixedly arranged inside the housing, the rotor assembly is arranged inside the magnetic levitation assembly, and the magnetic levitation assembly is used to support the rotor assembly to achieve magnetic levitation; the motor assembly is arranged on the inner side wall of the housing and outside the magnetic levitation assembly, and is used to drive the rotor assembly to rotate; the rotor assembly includes a rotor 7 and a rotor disc 9, the rotor disc 9 is fixedly sleeved on the rotor 7, and the motor assembly acts on the rotor disc 9 to drive the rotor assembly to rotate.

[0025] The present invention proposes a deep integration architecture of an axial magnetic levitation bearing and an axial motor. By combining the thrust disc controlled by the axial magnetic bearing with the axial motor, the axial length is significantly shortened, and the critical speed is greatly increased. Embodiment 2. The present invention provides an axial flux magnetic levitation compressor, which specifically includes: An axial flux magnetic levitation compressor, which is structurally compact and efficient, mainly includes a motor assembly, a rotor assembly, a magnetic levitation assembly, and a housing. The magnetic levitation assembly is fixedly arranged inside the housing, while the rotor assembly is cleverly arranged inside the magnetic levitation assembly, and the magnetic levitation state of the rotor is realized through the support of the magnetic levitation assembly. The motor assembly is installed on the inner side wall of the housing and outside the magnetic levitation assembly, and is responsible for driving the rotor assembly to rotate.

[0026] The rotor assembly is composed of a rotor 7 and a rotor disc 9, wherein the rotor disc 9 is fixedly sleeved on the rotor 7, serving as the acting point of the motor assembly to drive the entire rotor assembly to rotate.

[0027] The design of the rotor disc 9 is very delicate, including a thrust disc 15, a spacer disc 17, and permanent magnets 16. The thrust disc 15 is fixedly sleeved on the rotor 7, the spacer disc 17 is an annular disc and is fixedly sleeved outside the thrust disc 15, and several permanent magnets 16 are embedded in the spacer disc 17 according to the Halbach array, and the adjacent permanent magnets 16 have opposite magnetic polarities to enhance the magnetic flux in the air gap and reduce magnetic leakage.

[0028] The spacer disk 17 is made of non-magnetic material to isolate the magnetic field, and the permanent magnet 16 is embedded in the spacer disk 17 to protect its safety during high-speed rotation. The magnetic levitation assembly consists of an axial magnetic levitation bearing 8 and a radial magnetic levitation bearing 11. The two radial magnetic levitation bearings 11 are symmetrically arranged inside the housing, and the two axial magnetic levitation bearings 8 are arranged between the two radial magnetic levitation bearings 11. The rotor 7 passes through the inner sides of these bearings, and the rotor disk 9 is located between the two axial magnetic levitation bearings 8.

[0029] The motor assembly consists of a motor stator 2 and a motor coil 1 wound thereon, which is arranged outside the two axial magnetic levitation bearings 8 and is magnetically isolated by a magnetic isolation material 10.

[0030] This compressor uses an axial motor to replace the traditional radial motor structure, greatly reducing the axial length of the system, and integrating the stator of the axial magnetic levitation bearing with the stator of the axial motor, with the common force acting on the same rotor disk.

[0031] Its working principle is as follows: First, a control current is passed through the axial magnetic levitation bearing coil 3 to generate an axial force, controlling the axial displacement of the thrust disk 15 and suspending the rotor 7 to the central position. Secondly, the permanent magnets 16 on the outer side of the thrust disk 15 are arranged in a Halbach array to enhance the air-gap magnetic flux and improve the power density of the axial motor. Then, three-phase alternating current is passed through the motor stator coils 1 on both sides to generate a rotating magnetic field, which interacts with the fixed magnetic field of the permanent magnet 16 to drive the rotor disk 9 to rotate, and the rotational speed is adjusted by changing the frequency of the alternating current; in addition, the thrust disk 15 is made of high-strength magnetic conductive material At the same time, the permanent magnet 16 is embedded in a high-strength spacer disk and fixed by interference fit to protect its safety during high-speed rotation. Finally, the radial magnetic levitation bearing 11 supports the rotor to be radially suspended, and protective bearings 4 are provided on both sides of the compressor to prevent the rotor from falling. The rotor 7 is also connected with impellers 6, 13 and volutes 5, 14 outside the housing to realize the normal operation of the compressor.

[0032] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An axial flux magnetic levitation compressor, characterized in that, It includes a motor assembly, a rotor assembly, a magnetic levitation assembly and a housing; the magnetic levitation assembly is fixedly arranged inside the housing, the rotor assembly is arranged inside the magnetic levitation assembly, and the magnetic levitation assembly is used to support the rotor assembly to achieve magnetic levitation; the motor assembly is arranged on the inner side wall of the housing and outside the magnetic levitation assembly, and is used to drive the rotor assembly to rotate; the rotor assembly includes a rotor (7) and a rotor disk (9), the rotor disk (9) is fixedly sleeved on the rotor (7), and the motor assembly acts on the rotor disk (9) to drive the rotor assembly to rotate.

2. The axial flux magnetic levitation compressor according to claim 1, wherein The rotor disk (9) includes a thrust disk (15), a magnetic isolation disk (17) and a permanent magnet (16); the thrust disk (15) is fixedly sleeved on the rotor (7), the magnetic isolation disk (17) is an annular disk, the magnetic isolation disk (17) is fixedly sleeved outside the thrust disk (15), and a plurality of permanent magnets (16) are nested on the magnetic isolation disk (17).

3. The axial flux magnetic levitation compressor according to claim 2, wherein The magnetic isolation disk (17) is made of non-magnetic conductive material.

4. The axial flux magnetic levitation compressor according to claim 2, wherein The permanent magnets (16) are embedded on the magnetic isolation disk (17) according to the Halbach array, and the adjacent permanent magnets (16) have opposite polarities.

5. The axial flux magnetic levitation compressor according to claim 2, wherein, The thrust disk (15) is a magnetic conductive material disk.

6. The axial flux magnetic levitation compressor according to claim 2, characterized in that, The magnetic levitation assembly includes an axial magnetic levitation bearing (8) and a radial magnetic levitation bearing (11), two radial magnetic levitation bearings (11) are symmetrically arranged inside the housing, two axial magnetic levitation bearings (8) are arranged between the two radial magnetic levitation bearings (11), the rotor (7) passes through and is arranged inside the axial magnetic levitation bearing (8) and the radial magnetic levitation bearing (11), and the rotor disk (9) is located between the two axial magnetic levitation bearings (8).

7. The axial flux magnetic levitation compressor according to claim 6, characterized in that, The motor assembly includes a motor stator (2) and a motor coil (1), and the motor coil (1) is wound around the motor stator (2); the motor assembly is arranged outside the two axial magnetic levitation bearings (8) and is isolated by a magnetic isolation material (10).

8. The axial flux magnetic levitation compressor according to claim 6, wherein The thrust disk (15) of the rotor disk (9) is located between the two axial magnetic levitation bearings (8), and the permanent magnet (16) of the rotor disk (9) is located between the motor assemblies.

9. The axial flux magnetic levitation compressor according to claim 1, wherein, Two protective bearings (4) are also symmetrically arranged on the housing, and the rotor (7) is arranged between the two protective bearings (4).

10. The axial flux magnetic levitation compressor according to claim 1, characterized in that, The rotor (7) is connected with two-stage impellers and a volute outside the housing.

Images