Magnetic- aerodynamic hybrid bearing centrifugal compressor

Abstract

This application relates to a magnetic-pneumatic hybrid bearing centrifugal compressor, comprising: a rotor, a stator, a housing, a first radial foil bearing, a second radial foil bearing, a first thrust foil bearing, a thrust plate, a second thrust foil bearing, and a permanent magnet bearing. The permanent magnet bearing includes an inner magnetic ring and an outer magnetic ring spaced apart, with the inner magnetic ring fixedly connected to the rotor and the outer magnetic ring fixedly connected to the housing. Therefore, during the start-up and shutdown of the magnetic-pneumatic hybrid bearing centrifugal compressor, when the load-bearing capacity of the first thrust foil bearing or the load-bearing capacity provided by the second thrust foil bearing cannot offset the axial force from the rotor, the attraction force generated by the outer magnetic ring on the inner magnetic ring can offset the axial force from the rotor, reducing the axial movement of the rotor, improving the axial stability of the rotor, reducing the friction between the first and second thrust foil bearings and the thrust plate, and improving the durability and performance of the first and second thrust foil bearings.

Description

Technical Field

[0001] This application relates to the field of compressor technology, specifically to a magnetic hybrid bearing centrifugal compressor. Background Technology

[0002] Currently, high-speed centrifugal compressors mostly use foil bearings. Foil bearings include radial foil bearings and thrust foil bearings, with the main function of thrust foil bearings being to counteract the axial force from the rotor.

[0003] When a high-speed centrifugal compressor operates under different pressures, the impeller is affected by varying pressure differentials, causing the rotor's axial force to change accordingly. The axial load capacity of the thrust foil bearing is limited by the operating speed, generally increasing with increasing speed. The pressure differential changes are most drastic during the start-up and shutdown of a high-speed centrifugal compressor, leading to increased variations in the rotor's axial force. During these processes, the thrust foil bearing provides relatively less axial load capacity, resulting in increased axial runout and reduced rotor stability. Furthermore, during startup and shutdown, a gas film has not yet formed between the top foil surface of the thrust foil bearing and the thrust disc, causing intense friction between them. Increased rotor axial runout further exacerbates this friction, further reducing the thrust foil bearing's durability and performance. Summary of the Invention

[0004] This application provides a magnetic-gas hybrid bearing centrifugal compressor, which can solve the technical problem that in the current high-speed centrifugal compressor, the axial load capacity of the thrust foil bearing is small during the start-up and shutdown process, resulting in a large axial movement of the rotor, which leads to increased friction between the top foil of the thrust foil bearing and the thrust plate, and low durability of the thrust foil bearing.

[0005] This application provides a magnetic-gas hybrid bearing centrifugal compressor, comprising: a rotor, a stator, a housing, a first radial foil bearing, a second radial foil bearing, a first thrust foil bearing, a thrust plate, a second thrust foil bearing, a permanent magnet bearing, a first impeller, and a second impeller; the rotor has a first end and a second end in the axial direction, the stator is sleeved on the middle of the rotor, the housing is sleeved on the stator, and the stator is fixedly connected to the housing; the first radial foil bearing and the first impeller are sequentially sleeved on the first end of the rotor along the direction from the second end to the first end, and the first radial foil bearing is fixedly connected. The first impeller is fixedly connected to the rotor. The second radial foil bearing, the first thrust foil bearing, the thrust plate, the second thrust foil bearing, the permanent magnet bearing, and the second impeller are sequentially sleeved on the second end of the rotor along the direction from the first end to the second end. The second radial foil bearing, the first thrust foil bearing, and the second thrust foil bearing are all fixedly connected to the casing, and the thrust plate and the second impeller are all fixedly connected to the rotor. The permanent magnet bearing includes an inner magnetic ring and an outer magnetic ring spaced apart. The inner magnetic ring is fixedly connected to the rotor, the outer magnetic ring is sleeved on the inner magnetic ring, and the outer magnetic ring is fixedly connected to the casing.

[0006] In some embodiments, the magnetic-gas hybrid bearing centrifugal compressor further includes: a first seal, sleeved on the first end of the rotor and located between the first impeller and the first radial foil bearing, the first seal being fixedly connected to the first radial foil bearing; a first end cover, sleeved on the first end of the rotor and the first radial foil bearing, the first end cover being fixedly connected to the housing; a first connector, sleeved on the first radial foil bearing and the first seal, the first connector being fixedly connected to the side of the first end cover away from the housing; and a diffuser, sleeved on the first impeller and the first seal, the diffuser being fixedly connected to the side of the first connector away from the housing.

[0007] In some embodiments, the first radial foil bearing is fixedly connected to the first connector.

[0008] In some embodiments, the magnetic hybrid bearing centrifugal compressor further includes: a second end cover, sleeved on the second end of the rotor and the second radial foil bearing, the second end cover being fixedly connected to the housing; a second connecting member, sleeved on the second radial foil bearing, the first thrust foil bearing, the thrust plate and the second thrust foil bearing, the second connecting member being fixedly connected to the side of the second end cover away from the housing; and a second seal, sleeved on the permanent magnet bearing and fixedly connected to the side of the second connecting member away from the housing.

[0009] In some embodiments, a second radial foil bearing is fixedly connected to a second end cap, a first thrust foil bearing is fixedly connected to a second radial foil bearing, a second thrust foil bearing is fixedly connected to a second seal, and an outer magnetic ring is fixedly connected to a second seal.

[0010] In some embodiments, the second seal is at least partially disposed between the outer magnetic ring and the second thrust foil bearing, the second thrust foil bearing being fixedly connected to the side of the second seal near the first end, and the outer magnetic ring being fixedly connected to the side of the second seal away from the first end.

[0011] In some embodiments, the outer magnetic ring is fixedly connected to the second seal by adhesive.

[0012] In some embodiments, the thrust disc at least partially presses against the side of the inner magnetic ring near the first end, and the second impeller at least partially presses against the side of the inner magnetic ring away from the first end.

[0013] In some embodiments, the thrust disc has a first portion and a second portion fixedly connected, the second portion being sleeved on the first portion, and the thickness of the second portion in the axial direction of the rotor being less than the thickness of the first portion in the axial direction of the rotor; a first thrust foil bearing and a second thrust foil bearing are disposed on both sides of the second portion, and the first portion abuts against the side of the inner magnetic ring near the first end.

[0014] In some embodiments, the magnetic-gas hybrid bearing centrifugal compressor further includes: a first protective layer disposed on the surface of the inner magnetic ring near the first end; and a second protective layer disposed on the surface of the inner magnetic ring away from the first end; wherein the thrust plate at least partially abuts against the side of the first protective layer near the first end, and the second impeller at least partially abuts against the side of the second protective layer away from the first end.

[0015] In some embodiments, the first impeller has a first through hole, the second impeller has a second through hole, the first end of the rotor has a first receiving groove, and the second end of the rotor has a second receiving groove; the magnetic mixing bearing centrifugal compressor further includes: a first tie rod, one end of which abuts against the side of the first impeller away from the casing, and the other end of which passes through the first through hole and extends into the first receiving groove to cooperate with the first receiving groove to fix the first impeller and the rotor; and a second tie rod, one end of which abuts against the side of the second impeller away from the casing, and the other end of which passes through the second through hole and extends into the second receiving groove to cooperate with the second receiving groove to fix the second impeller and the rotor.

[0016] In some embodiments, the magnetic-gas hybrid bearing centrifugal compressor further includes: a first volute, sleeved on the first connector, diffuser and first impeller, and fixedly connected to the side of the first connector away from the casing; a first guide fluid, sleeved on the first impeller and fixedly connected to the first volute; a second volute, sleeved on the second connector, second seal and second impeller, and fixedly connected to the side of the second connector away from the casing; and a second guide fluid, sleeved on the second impeller and fixedly connected to the second volute.

[0017] In some embodiments, the first seal includes a labyrinth seal, and the surface of the first seal near the rotor is provided with first sealing teeth.

[0018] In some embodiments, the second seal includes a labyrinth seal, and the surface of the second seal near the second impeller is provided with second sealing teeth.

[0019] The magnetic-gas hybrid bearing centrifugal compressor provided in this application has a permanent magnet bearing fitted at the second end of the rotor. The inner magnetic ring of the permanent magnet bearing is fixedly connected to the rotor, and the outer magnetic ring of the permanent magnet bearing is fixedly connected to the casing. Thus, during the start-up and shutdown process of the magnetic-gas hybrid bearing centrifugal compressor, when the bearing capacity provided by the first thrust foil bearing or the second thrust foil bearing cannot offset the axial force from the rotor, the attraction force generated by the outer magnetic ring on the inner magnetic ring can be used to offset the axial force from the rotor, reduce the axial movement of the rotor, improve the axial stability of the rotor, reduce the friction between the top foil of the first thrust foil bearing and the thrust plate, and reduce the friction between the top foil of the second thrust foil bearing and the thrust plate, thereby improving the durability and performance of the first thrust foil bearing and the second thrust foil bearing. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of a magnetic hybrid bearing centrifugal compressor according to an embodiment of this application. Figure 1 ;

[0022] Figure 2 This is a schematic diagram of the structure of a magnetic hybrid bearing centrifugal compressor according to an embodiment of this application. Figure 2 ;

[0023] Figure 3 This is an exploded view of a magnetic hybrid bearing centrifugal compressor according to an embodiment of this application;

[0024] Figure 4 This is a cross-sectional view of a magnetic hybrid bearing centrifugal compressor according to an embodiment of this application;

[0025] Figure 5 for Figure 4 Enlarged view of point A in the middle circle;

[0026] Figure 6 for Figure 4 Enlarged view of point B in the middle circle;

[0027] Figure 7 This is a schematic diagram of the rotor, stator, and housing structure according to an embodiment of this application. Figure 1 ;

[0028] Figure 8 This is a schematic diagram of the rotor, stator, and housing structure according to an embodiment of this application. Figure 2 ;

[0029] Figure 9 This is a schematic diagram of the rotor, first radial foil bearing, first seal, first impeller, and first tie rod according to an embodiment of this application. Figure 1 ;

[0030] Figure 10 This is a schematic diagram of the rotor, first radial foil bearing, first seal, first impeller, and first tie rod according to an embodiment of this application. Figure 2 ;

[0031] Figure 11 This is a schematic diagram of the structure of the first end cap, first connector, diffuser, first volute, and first fluid guide in an embodiment of this application. Figure 1 ;

[0032] Figure 12 This is a schematic diagram of the structure of the first end cap, first connector, diffuser, first volute, and first fluid guide in an embodiment of this application. Figure 2 ;

[0033] Figure 13 This is a schematic diagram of the structure of the second radial foil bearing, the first thrust foil bearing, the thrust plate, the second thrust foil bearing, the first protective layer, the permanent magnet bearing, the second protective layer, the second impeller, and the second tie rod according to an embodiment of this application. Figure 1 ;

[0034] Figure 14 This is a schematic diagram of the structure of the second radial foil bearing, the first thrust foil bearing, the thrust plate, the second thrust foil bearing, the first protective layer, the permanent magnet bearing, the second protective layer, the second impeller, and the second tie rod according to an embodiment of this application. Figure 2 ;

[0035] Figure 15 This is a schematic diagram of the structure of the second end cap, second connector, second seal, second volute, and second fluid guide in an embodiment of this application. Figure 1 ;

[0036] Figure 16 This is a schematic diagram of the structure of the second end cap, second connector, second seal, second volute, and second fluid guide in an embodiment of this application. Figure 1 ;

[0037] Figure 17 This is a left view of the thrust plate according to an embodiment of this application;

[0038] Figure 18This is a right view of the thrust plate according to an embodiment of this application;

[0039] Figure 19 This is a cross-sectional view of the thrust plate according to an embodiment of this application;

[0040] Figure 20 This is a left view of the permanent magnet bearing according to an embodiment of this application;

[0041] Figure 21 This is a cross-sectional view of a permanent magnet bearing according to an embodiment of this application;

[0042] Figure 22 This is a left view of the thrust plate according to an embodiment of this application;

[0043] Figure 23 This is a right view of the thrust plate according to an embodiment of this application;

[0044] Figure 24 This is a cross-sectional view of the thrust plate according to an embodiment of this application.

[0045] The components in the diagram are labeled as follows:

[0046] 100. Magnetic-pneumatic hybrid bearing centrifugal compressor;

[0047] 1. Rotor; 2. Stator; 3. Housing; 4. First radial foil bearing; 5. Second radial foil bearing; 6. First thrust foil bearing; 7. Thrust plate; 8. Second thrust foil bearing; 9. Permanent magnet bearing; 10. First impeller; 11. Second impeller; 12. First seal; 13. First end cover; 14. First connector; 15. Diffuser; 16. Second end cover; 17. Second connector; 18. Second seal; 19. First protective layer; 20. Second protective layer; 21. First tie rod; 22. Second tie rod; 23. First volute; 24. First guide fluid; 25. Second volute; 26. Second guide fluid;

[0048] 101. First end; 102. Second end; 103. First receiving groove; 104. Second receiving groove;

[0049] 1001, First through hole; 1101, Second through hole;

[0050] 701. First Division; 702. Second Division;

[0051] 901. Inner magnetic ring; 902. Outer magnetic ring;

[0052] 1201, First sealing comb tooth; 1801, Second sealing comb tooth. Detailed Implementation

[0053] The preferred embodiments of this application are described in detail below with reference to the accompanying drawings to fully introduce the technical content of this application to those skilled in the art, to demonstrate that this application can be implemented, and to make the disclosed technical content of this application clearer, so that those skilled in the art can more easily understand how to implement this application. However, this application can be embodied in many different forms of embodiments, and the protection scope of this application is not limited to the embodiments mentioned herein. The description of the embodiments below is not intended to limit the scope of this application.

[0054] The directional terms used in this application, such as "up", "down", "front", "back", "left", "right", "inside", "outside", and "side", are only for the directions shown in the accompanying drawings. The directional terms used herein are for the purpose of explaining and illustrating this application, and not for limiting the scope of protection of this application.

[0055] In the accompanying drawings, components with the same structure are indicated by the same numerical designation, and components with similar structures or functions are indicated by similar numerical designations. Furthermore, for ease of understanding and description, the dimensions and thicknesses of each component shown in the drawings are arbitrary, and this application does not limit the dimensions and thicknesses of each component.

[0056] Example 1

[0057] Please see Figures 1-6 This application provides a magnetic-pneumatic hybrid bearing centrifugal compressor 100. The magnetic-pneumatic hybrid bearing centrifugal compressor 100 includes: a rotor 1, a stator 2, a housing 3, a first radial foil bearing 4, a second radial foil bearing 5, a first thrust foil bearing 6, a thrust plate 7, a second thrust foil bearing 8, a permanent magnet bearing 9, a first impeller 10, a second impeller 11, a first seal 12, a first end cover 13, a first connector 14, a diffuser 15, a second end cover 16, a second connector 17, a second seal 18, a first protective layer 19, a second protective layer 20, a first tie rod 21, a second tie rod 22, a first volute 23, a first guide fluid 24, a second volute 25, and a second guide fluid 26.

[0058] Please see Figures 1-8 The rotor 1 has a first end 101 and a second end 102 in the axial direction.

[0059] Please see Figures 1-8 The stator 2 is fitted onto the middle of the rotor 1. That is, the stator 2 is located between the first end 101 and the second end 102 of the rotor 1. It is worth noting that there is a gap between the stator 2 and the rotor 1, meaning that the stator 2 does not rotate as the rotor 1 rotates.

[0060] Please see Figures 1-8 The housing 3 is fitted onto the stator 2, and the stator 2 is fixedly connected to the housing 3. Specifically, the outer wall of the stator 2 is fixedly connected to the inner wall of the housing 3.

[0061] Please see Figures 1-6 , Figures 9-10 A first radial foil bearing 4 is sleeved on the first end 101 of the rotor 1. The first radial foil bearing 4 is fixedly connected to the housing 3. Specifically, the first radial foil bearing 4 is fixedly connected to the first connecting member 14. In this embodiment, the first radial foil bearing 4 is fixedly connected to the first connecting member 14 by a first bolt (not shown).

[0062] Please see Figures 1-6 , Figures 9-10 A first seal 12 is fitted onto the first end 101 of the rotor 1. The first seal 12 is located on the side of the first radial foil bearing 4 away from the second end 102. The first seal 12 is fixedly connected to the first radial foil bearing 4. In this embodiment, a first bolt (not shown) passes through the first seal 12 and the first radial foil bearing 4 and cooperates with the first connecting member 14 to achieve a fixed connection between the first seal 12, the first radial foil bearing 4, and the first connecting member 14. In this embodiment, the first seal 12 is a labyrinth seal. The surface of the first seal 12 near the rotor 1 is provided with first sealing comb teeth 1201.

[0063] Please see Figures 1-6 , Figures 9-10 The first impeller 10 is sleeved on the first end 101 of the rotor 1. The first impeller 10 is located on the side of the first seal 12 away from the second end 102. The first impeller 10 is fixedly connected to the rotor 1. Specifically, the first impeller 10 is provided with a first through hole 1001, and the first end 101 of the rotor 1 is provided with a first receiving groove 103. One end of the first pull rod 21 abuts against the side of the first impeller 10 away from the housing 3, and the other end of the first pull rod 21 passes through the first through hole 1001 and extends into the first receiving groove 103 to cooperate with the first receiving groove 103 to fix the first impeller 10 and the rotor 1.

[0064] Please see Figures 1-6 , Figures 11-12 The first end cover 13 is sleeved on the first end 101 of the rotor 1 and the first radial foil bearing 4. The first end cover 13 is fixedly connected to the housing 3. In this embodiment, the first end cover 13 is fixedly connected to the housing 3 by a second bolt (not shown).

[0065] Please see Figures 1-6 , Figures 11-12 The first connecting member 14 is sleeved on the first radial foil bearing 4 and the first seal 12. The first connecting member 14 is fixedly connected to the side of the first end cover 13 away from the housing 3. In this embodiment, the first connecting member 14 is fixedly connected to the first end cover 13 by a third bolt (not shown).

[0066] Please see Figures 1-6 , Figures 11-12 The diffuser 15 is sleeved on the first impeller 10 and the first seal 12. The diffuser 15 is fixedly connected to the first connector 14 on the side away from the housing 3. In this embodiment, a third bolt (not shown) passes through the diffuser 15 and the first connector 14 and cooperates with the first end cover 13 to achieve a fixed connection between the diffuser 15, the first connector 14 and the first end cover 13.

[0067] Please see Figures 1-6 , Figures 11-12 The first volute 23 is sleeved on the first connector 14, the diffuser 15, and the first impeller 10. The first volute 23 is fixedly connected to the side of the first connector 14 away from the housing 3. In this embodiment, the first volute 23 is fixedly connected to the first connector 14 by a fourth bolt (not shown).

[0068] Please see Figures 1-6 , Figures 11-12 The first guide fluid 24 is sleeved on the first impeller 10 and fixedly connected to the first volute 23. In this embodiment, the first guide fluid 24 and the first volute 23 are integrally formed.

[0069] Please see Figures 1-6 , Figures 13-14 The second radial foil bearing 5 is sleeved on the second end 102 of the rotor 1. The second radial foil bearing 5 is fixedly connected to the housing 3. In this embodiment, the second radial foil bearing 5 is fixedly connected to the second end cover 16 by a fifth bolt (not shown).

[0070] Please see Figures 1-6 , Figures 13-14 A first thrust foil bearing 6 is sleeved on the second end 102 of the rotor 1. The first thrust foil bearing 6 is located on the side of the second radial foil bearing 5 away from the first end 101. The first thrust foil bearing 6 is fixedly connected to the housing 3. Specifically, the first thrust foil bearing 6 is fixedly connected to the second radial foil bearing 5. In this embodiment, the first thrust foil bearing 6 is fixed to the surface of the second radial foil bearing 5 away from the first end 101 by a first countersunk screw (not shown).

[0071] Please see Figures 1-6 , Figures 13-14 The thrust disc 7 is sleeved on the second end 102 of the rotor 1. The thrust disc 7 is located on the side of the first thrust foil bearing 6 away from the first end 101. The thrust disc 7 is fixedly connected to the rotor 1. In this embodiment, the thrust disc 7 is fixedly connected to the rotor 1 by a heat-fitting process.

[0072] Please see Figures 17-19The thrust disc 7 has a first portion 701 and a second portion 702 that are fixedly connected. The second portion 702 is sleeved on the first portion 701, and the thickness of the second portion 702 in the axial direction of the rotor 1 is less than the thickness of the first portion 701 in the axial direction of the rotor 1. The first thrust foil bearing 6 is disposed on the side of the second portion 702 near the first end 101.

[0073] Please see Figures 1-6 , Figures 13-14 The second thrust foil bearing 8 is sleeved on the second end 102 of the rotor 1. The second thrust foil bearing 8 is located on the side of the thrust disc 7 away from the first end 101. The second thrust foil bearing 8 is fixedly connected to the housing 3. The second thrust foil bearing 8 is fixedly connected to the second seal 18. In this embodiment, the second thrust foil bearing 8 is fixed to the surface of the second seal 18 near the first end 101 by a second countersunk screw (not shown). The second thrust foil bearing 8 is disposed on the side of the second portion 702 away from the first end 101.

[0074] Please see Figures 1-6 , Figures 13-14 Please refer to Figures 20-21 The permanent magnet bearing 9 is sleeved on the second end 102 of the rotor 1. The permanent magnet bearing 9 is located on the side of the second thrust foil bearing 8 away from the first end 101. The permanent magnet bearing 9 includes an inner magnetic ring 901 and an outer magnetic ring 902 arranged at intervals, with the outer magnetic ring 902 sleeved on the inner magnetic ring 901.

[0075] Please see Figures 1-6 , Figures 13-14 The inner magnetic ring 901 is fixedly connected to the rotor 1. Specifically, the thrust disc 7 at least partially abuts against the side of the inner magnetic ring 901 near the first end 101, and the second impeller 11 at least partially abuts against the side of the inner magnetic ring 901 away from the first end 101. Since both the second impeller 11 and the thrust disc 7 are fixedly connected to the rotor 1, the fixed connection between the inner magnetic ring 901, the thrust disc 7, and the second impeller 11 is achieved by the second impeller 11 and the thrust disc 7 abutting against both sides of the inner magnetic ring 901. In this embodiment, the first portion 701 of the thrust disc 7 abuts against the side of the inner magnetic ring 901 near the first end 101.

[0076] Please see Figures 1-6 , Figures 13-14 In this embodiment, the first protective layer 19 is disposed on the surface of the inner magnetic ring 901 near the first end 101; the second protective layer 20 is disposed on the surface of the inner magnetic ring 901 away from the first end 101. The first portion 701 of the thrust disc 7 presses against the side of the first protective layer 19 near the first end 101, and the second impeller 11 at least partially presses against the side of the second protective layer 20 away from the first end 101.

[0077] Please see Figures 1-6 , Figures 13-14 The outer magnetic ring 902 is fixedly connected to the housing 3. Specifically, the outer magnetic ring 902 is fixedly connected to the second seal 18. In this embodiment, the outer magnetic ring 902 is fixedly connected to the second seal 18 by adhesive (not shown).

[0078] Please see Figures 1-6 , Figures 13-14 The second impeller 11 is fitted onto the second end 102 of the rotor 1. The second impeller 11 is located on the side of the permanent magnet bearing 9 away from the first end 101. The second impeller 11 is fixedly connected to the rotor 1. Specifically, the second impeller 11 is provided with a second through hole 1101, and the second end 102 of the rotor 1 is provided with a second receiving groove 104. One end of the second tie rod 22 abuts against the side of the second impeller 11 away from the housing 3, and the other end of the second tie rod 22 passes through the second through hole 1101 and extends into the second receiving groove 104 to cooperate with the second receiving groove 104 to fix the second impeller 11 and the rotor 1.

[0079] Please see Figures 1-6 , Figures 15-16 The second end cover 16 is sleeved on the second end 102 of the rotor 1 and the second radial foil bearing 5. The second end cover 16 is fixedly connected to the housing 3. In this embodiment, the second end cover 16 is fixedly connected to the housing 3 by a sixth bolt (not shown).

[0080] Please see Figures 1-6 , Figures 15-16 The second connecting member 17 is sleeved on the second radial foil bearing 5, the first thrust foil bearing 6, the thrust plate 7, and the second thrust foil bearing 8. The second connecting member 17 is fixedly connected to the side of the second end cover 16 away from the housing 3. In this embodiment, the second connecting member 17 is fixedly connected to the second end cover 16 by a seventh bolt (not shown).

[0081] Please see Figures 1-6 , Figures 15-16 , Figures 21-24 The second seal 18 is sleeved on the permanent magnet bearing 9. The second seal 18 is fixedly connected to the side of the second connector 17 away from the housing 3. In this embodiment, the seventh bolt (not shown) passes through the second seal 18 and the second connector 17 and cooperates with the second end cover 16 to achieve a fixed connection between the second seal 18, the second connector 17 and the second end cover 16.

[0082] Please see Figures 1-6 , Figures 15-16 , Figures 21-24The second seal 18 is at least partially disposed between the outer magnetic ring 902 and the second thrust foil bearing 8. The second thrust foil bearing 8 is fixedly connected to the side of the second seal 18 near the first end 101, and the outer magnetic ring 902 is fixedly connected to the side of the second seal 18 away from the first end 101. In this embodiment, the second seal 18 is a labyrinth seal, and the surface of the second seal 18 near the second impeller 11 is provided with second sealing comb teeth 1801.

[0083] Please see Figures 1-6 , Figures 15-16 The second volute 25 is sleeved on the second connector 17, the second seal 18, and the second impeller 11. The second volute 25 is fixedly connected to the side of the second connector 17 away from the housing 3. In this embodiment, the second volute 25 is fixedly connected to the second connector 17 by an eighth bolt (not shown).

[0084] Please see Figures 1-6 , Figures 15-16 The second guide fluid 26 is sleeved on the second impeller 11 and fixedly connected to the second volute 25. In this embodiment, the second guide fluid 26 and the second volute 25 are integrally formed.

[0085] In summary, the magnetic hybrid bearing centrifugal compressor 100 provided in this application has a permanent magnet bearing 9 fitted at the second end 102 of the rotor 1. The inner magnetic ring 901 of the permanent magnet bearing 9 is fixedly connected to the rotor 1, and the outer magnetic ring 902 of the permanent magnet bearing 9 is fixedly connected to the housing 3. Thus, during the start-up and stop of the magnetic hybrid bearing centrifugal compressor 100, when the bearing capacity provided by the first thrust foil bearing 6 or the second thrust foil bearing 8 cannot offset the axial force from the rotor 1, the attraction force generated by the outer magnetic ring 902 on the inner magnetic ring 901 can be used to offset the axial force from the rotor 1, reduce the axial movement of the rotor 1, improve the axial stability of the rotor 1, reduce the friction between the top foil of the first thrust foil bearing 6 and the thrust plate 7, and reduce the friction between the top foil of the second thrust foil bearing 8 and the thrust plate 7, thereby improving the durability and performance of the first thrust foil bearing 6 and the second thrust foil bearing 8. Meanwhile, the axial force provided by the permanent magnet bearing 9 is not limited by the rotational speed. It only generates a restoring force when the rotor 1 moves axially away from the equilibrium position. This means that under any operating condition, the permanent magnet bearing 9 can increase the upper limit of the load-bearing capacity of the original first thrust foil bearing 6 or the original second thrust foil bearing 8. This helps to reduce the failure of the first thrust foil bearing 6 or the second thrust foil bearing 8 due to excessive load.

[0086] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0087] The foregoing has provided a detailed description of a magnetic hybrid bearing centrifugal compressor according to the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A magnetic- aerodynamic hybrid bearing centrifugal compressor, characterized in that, Comprise: A rotor (1), a stator (2), a casing (3), a first radial foil bearing (4), a second radial foil bearing (5), a first thrust foil bearing (6), a thrust disc (7), a second thrust foil bearing (8), a permanent magnetic bearing (9), a first impeller (10) and a second impeller (11); The rotor (1) has a first end (101) and a second end (102) in the axial direction, the stator (2) is sleeved on the middle part of the rotor (1), and the casing (3) is sleeved on the stator (2), and the stator (2) is fixedly connected to the casing (3); The first radial foil bearing (4) and the first impeller (10) are sequentially sleeved on the first end (101) of the rotor (1) along the direction from the second end (102) to the first end (101), the first radial foil bearing (4) is fixedly connected to the casing (3), and the first impeller (10) is fixedly connected to the rotor (1); The second radial foil bearing (5), the first thrust foil bearing (6), the thrust disc (7), the second thrust foil bearing (8), the permanent magnetic bearing (9) and the second impeller (11) are sequentially sleeved on the second end (102) of the rotor (1) along the direction from the first end (101) to the second end (102), the second radial foil bearing (5), the first thrust foil bearing (6) and the second thrust foil bearing (8) are all fixedly connected to the casing (3), and the thrust disc (7) and the second impeller (11) are all fixedly connected to the rotor (1); Wherein, the permanent magnetic bearing (9) comprises an inner magnetic ring (901) and an outer magnetic ring (902) arranged at intervals, the inner magnetic ring (901) is fixedly connected to the rotor (1), the outer magnetic ring (902) is sleeved on the inner magnetic ring (901), and the outer magnetic ring (902) is fixedly connected to the casing (3); During the starting and stopping process of the magnetic gas hybrid bearing type centrifugal compressor, when the bearing capacity of the first thrust foil bearing (6) or the bearing capacity provided by the second thrust foil bearing (8) cannot offset the axial force from the rotor (1), the attractive force generated by the outer magnetic ring (902) on the inner magnetic ring (901) offsets the axial force from the rotor (1), so as to reduce the axial displacement of the rotor (1).

2. The magnetic- aerodynamic hybrid bearing centrifugal compressor of claim 1, wherein, Also comprise: A first seal (12) is sleeved on the first end (101) of the rotor (1) and located between the first impeller (10) and the first radial foil bearing (4), and the first seal (12) is fixedly connected to the first radial foil bearing (4); A first end cover (13) is sleeved on the first end (101) of the rotor (1) and the first radial foil bearing (4), and the first end cover (13) is fixedly connected to the casing (3); A first connecting piece (14) is sleeved on the first radial foil bearing (4) and the first sealing piece (12), and is fixedly connected to the first end cover (13) away from the shell (3); An expander (15) is sleeved on the first impeller (10) and the first sealing piece (12), and is fixedly connected to the first connecting piece (14) away from the shell (3).

3. The magnetic- gas hybrid bearing centrifugal compressor of claim 2, wherein, The first radial foil bearing (4) is fixedly connected to the first connecting piece (14).

4. The magnetic- aerodynamic hybrid bearing centrifugal compressor of claim 2, wherein, Further comprising: A second end cover (16) is sleeved on the second end (102) of the rotor (1) and the second radial foil bearing (5), and is fixedly connected to the shell (3); A second connecting piece (17) is sleeved on the second radial foil bearing (5), the first thrust foil bearing (6), the thrust disc (7) and the second thrust foil bearing (8), and is fixedly connected to the second end cover (16) away from the shell (3); And A second sealing piece (18) is sleeved on the permanent magnetic bearing (9), and is fixedly connected to the second connecting piece (17) away from the shell (3).

5. The magnetic- aerodynamic hybrid bearing centrifugal compressor of claim 4, wherein, The second radial foil bearing (5) is fixedly connected to the second end cover (16), the first thrust foil bearing (6) is fixedly connected to the second radial foil bearing (5), the second thrust foil bearing (8) is fixedly connected to the second sealing piece (18), and the outer magnetic ring (902) is fixedly connected to the second sealing piece (18).

6. The magnetic- aerodynamic hybrid bearing centrifugal compressor of claim 5, wherein, The second sealing piece (18) is at least partially arranged between the outer magnetic ring (902) and the second thrust foil bearing (8), the second thrust foil bearing (8) is fixedly connected to the second sealing piece (18) close to the first end (101), and the outer magnetic ring (902) is fixedly connected to the second sealing piece (18) away from the first end (101).

7. The magnetic- gas hybrid bearing centrifugal compressor of claim 5, wherein The outer magnetic ring (902) is fixedly connected to the second sealing piece (18) by adhesive.

8. The magnetic- aerodynamic hybrid bearing centrifugal compressor of claim 1, wherein, The thrust disc (7) is at least partially abutted against the inner magnetic ring (901) close to the first end (101), and the second impeller (11) is at least partially abutted against the inner magnetic ring (901) away from the first end (101).

9. The magnetic- gas hybrid bearing centrifugal compressor of claim 8, wherein, The thrust disc (7) has a first part (701) and a second part (702) fixedly connected, the second part (702) is sleeved on the first part (701), and the thickness of the second part (702) in the axial direction of the rotor (1) is less than the thickness of the first part (701) in the axial direction of the rotor (1); The first thrust foil bearing (6) and the second thrust foil bearing (8) are arranged on both sides of the second part (702), and the first part (701) is abutted against the inner magnetic ring (901) close to the first end (101).

10. The magnetic- gas hybrid bearing centrifugal compressor of claim 1, wherein, Further comprising: A first protective layer (19) is arranged on a surface of the inner magnetic ring (901) close to the first end (101); And A second protective layer (20) is arranged on a surface of the inner magnetic ring (901) away from the first end (101); Wherein, the thrust disc (7) is at least partially pressed against one side of the first protective layer (19) close to the first end (101), and the second impeller (11) is at least partially pressed against one side of the second protective layer (20) away from the first end (101).

11. The magnetic- gas hybrid bearing centrifugal compressor of claim 1, wherein, A first through hole (1001) is arranged on the first impeller (10), a second through hole (1101) is arranged on the second impeller (11), a first accommodating groove (103) is arranged on the first end (101) of the rotor (1), and a second accommodating groove (104) is arranged on the second end (102) of the rotor (1); The magnetic and gas hybrid bearing type centrifugal compressor further comprises: A first pull rod (21) is arranged, one end of which is abutted against one side of the first impeller (10) away from the casing (3), and the other end of which extends into the first accommodating groove (103) through the first through hole (1001) and cooperates with the first accommodating groove (103) to fix the first impeller (10) and the rotor (1); and A second pull rod (22) is arranged, one end of which is abutted against one side of the second impeller (11) away from the casing (3), and the other end of which extends into the second accommodating groove (104) through the second through hole (1101) and cooperates with the second accommodating groove (104) to fix the second impeller (11) and the rotor (1).

12. The magnetic- gas hybrid bearing centrifugal compressor of claim 4, wherein, Further comprising: A first volute (23) is arranged, which is sleeved on the first connecting piece (14), the diffuser (15) and the first impeller (10), and is fixedly connected to one side of the first connecting piece (14) away from the casing (3); A first flow guide (24) is arranged, which is sleeved on the first impeller (10) and is fixedly connected to the first volute (23); A second volute (25) is arranged, which is sleeved on the second connecting piece (17), the second sealing piece (18) and the second impeller (11), and is fixedly connected to one side of the second connecting piece (17) away from the casing (3); A second flow guide (26) is arranged, which is sleeved on the second impeller (11) and is fixedly connected to the second volute (25).

13. The magnetic- gas hybrid bearing centrifugal compressor of claim 2, wherein, The first sealing piece (12) comprises a labyrinth seal, and a first sealing comb (1201) is arranged on a surface of one side of the first sealing piece (12) close to the rotor (1).

14. The magnetic- gas hybrid bearing centrifugal compressor of claim 4, wherein, The second sealing piece (18) comprises a labyrinth seal, and a second sealing comb (1801) is arranged on a surface of one side of the second sealing piece (18) close to the second impeller (11).

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