Magnetic-gas hybrid bearing type centrifugal compressor

Abstract

The invention relates to a magnetic-gas hybrid bearing type centrifugal compressor. The magnetic-gas hybrid bearing type centrifugal compressor comprises a rotor, a stator, a machine shell, 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 comprises an inner magnetic ring and an outer magnetic ring which are arranged at an interval, the inner magnetic ring is fixedly connected to the rotor, and the outer magnetic ring is fixedly connected to the casing. Therefore, in the starting and stopping process of the magnetic-gas hybrid bearing type centrifugal compressor, when the bearing capacity of the first thrust foil bearing or the bearing capacity provided by the second thrust foil bearing cannot counteract the axial acting force from the rotor, the axial acting force from the rotor can be counteracted by utilizing the suction force generated by the outer magnetic ring to the inner magnetic ring; the axial displacement of the rotor is reduced, the axial stability of the rotor is improved, the friction degree between the first thrust foil bearing and the thrust plate and between the second thrust foil bearing and the thrust plate is reduced, and the durability and performance of the first thrust foil bearing and the second thrust foil bearing are improved.

Description

Technical Field

[0001] The present application relates to the technical field of compressors, and in particular to a magnetic hybrid bearing type centrifugal compressor. Background Art

[0002] At present, the bearings of high-speed centrifugal compressors are mostly foil bearings. Foil bearings include radial foil bearings and thrust foil bearings, among which the main function of thrust foil bearings is to offset the axial force from the rotor.

[0003] When the unit of a high-speed centrifugal compressor operates under different pressures, the impeller will be affected by different front and rear pressure differences, causing the axial force of the rotor to change with the operating conditions. The axial load-bearing capacity of the thrust foil bearing will be limited by the speed and generally increase with the increase of the speed. The pressure difference changes most dramatically during the start-up and stop process of the high-speed centrifugal compressor, resulting in an increase in the change of the axial force of the rotor. During the start-up and stop process of the high-speed centrifugal compressor, the axial load-bearing capacity that the thrust foil bearing can provide is relatively small, resulting in an increase in the axial movement of the rotor and a decrease in the axial stability of the rotor. Moreover, during the start-up and stop process of the high-speed centrifugal compressor, an air film has not yet been formed between the top foil surface of the thrust foil bearing and the thrust plate, resulting in intense friction between the top foil of the thrust foil bearing and the thrust plate. The increase in the axial movement of the rotor will further increase the friction between the top foil of the thrust foil bearing and the thrust plate, thereby further reducing the durability and performance of the thrust foil bearing. Summary of the invention

[0004] The embodiment of the present application provides a magnetic hybrid bearing centrifugal compressor, which can solve the technical problems that during the start-up and stop processes of current high-speed centrifugal compressors, the axial bearing capacity of the thrust foil bearing is small, resulting in large axial movement of the rotor, increased friction between the top foil of the thrust foil bearing and the thrust plate, and low durability of the thrust foil bearing.

[0005] The embodiment of the present application provides a magnetic hybrid bearing centrifugal compressor, which includes: a rotor, a stator, a casing, 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 magnetic 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 in the middle of the rotor, the casing is sleeved on the stator, and the stator is fixedly connected to the casing; 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 to the casing. To the casing, 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 magnetic 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, the thrust plate and the second impeller are both fixedly connected to the rotor; wherein the permanent magnetic bearing comprises an inner magnetic ring and an outer magnetic ring arranged at intervals, 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 hybrid bearing centrifugal compressor also includes: a first seal, which is sleeved on the first end of the rotor and located between the first impeller and the first radial foil bearing, and the first seal is fixedly connected to the first radial foil bearing; a first end cover, which is sleeved on the first end of the rotor and the first radial foil bearing, and the first end cover is fixedly connected to the casing; a first connecting member, which is sleeved on the first radial foil bearing and the first seal, and the first connecting member is fixedly connected to a side of the first end cover away from the casing; a diffuser, which is sleeved on the first impeller and the first seal, and the diffuser is fixedly connected to a side of the first connecting member away from the casing.

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

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

[0009] In some embodiments, the second radial foil bearing is fixedly connected to the second end cover, the first thrust foil bearing is fixedly connected to the second radial foil bearing, the second thrust foil bearing is fixedly connected to the second seal, and the outer magnetic ring is fixedly connected to the 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 is fixedly connected to a side of the second seal close to the first end, and the outer magnetic ring is fixedly connected to a side of the second seal away from the first end.

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

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

[0013] In some embodiments, the thrust plate has a first section and a second section that are fixedly connected, the second section is sleeved on the first section, and the thickness of the second section in the axial direction of the rotor is less than the thickness of the first section in the axial direction of the rotor; the first thrust foil bearing and the second thrust foil bearing are arranged on both sides of the second section, and the first section is pressed against the side of the inner magnetic ring close to the first end.

[0014] In some embodiments, the magnetic hybrid bearing centrifugal compressor also includes: a first protective layer, arranged on the surface of the inner magnetic ring close to the first end; and a second protective layer, arranged on the surface of the inner magnetic ring away from the first end; wherein the thrust plate is at least partially pressed against the side of the first protective layer close to the first end, and the second impeller is at least partially pressed against the side of the second protective layer away from the first end.

[0015] In some embodiments, a first through hole is provided on the first impeller, a second through hole is provided on the second impeller, a first receiving groove is provided on the first end of the rotor, and a second receiving groove is provided on the second end of the rotor; the magnetic hybrid bearing centrifugal compressor also includes: a first pull 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 pull 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 hybrid bearing centrifugal compressor also includes: a first volute, which is sleeved on the first connecting member, the diffuser and the first impeller, and is fixedly connected to the side of the first connecting member away from the casing; a first flow guide, which is sleeved on the first impeller and is fixedly connected to the first volute; a second volute, which is sleeved on the second connecting member, the second seal and the second impeller, and is fixedly connected to the side of the second connecting member away from the casing; a second flow guide, which is sleeved on the second impeller and is fixedly connected to the second volute.

[0017] In some embodiments, the first seal comprises a labyrinth seal, and a surface of the first seal close to the rotor is provided with first sealing comb teeth.

[0018] In some embodiments, the second seal comprises a labyrinth seal, and a surface of the second seal on a side close to the second impeller is provided with second sealing comb teeth.

[0019] The magnetic hybrid bearing centrifugal compressor provided by the present application has a permanent magnetic bearing sleeved on the second end of the rotor, the inner magnetic ring of the permanent magnetic bearing is fixedly connected to the rotor, and the outer magnetic ring of the permanent magnetic bearing is fixedly connected to the casing. Therefore, during the start-up and stop process of the magnetic hybrid bearing centrifugal compressor, when the bearing capacity of the first thrust foil bearing or the bearing capacity provided by the second thrust foil bearing cannot offset the axial force from the rotor, the suction force generated by the outer magnetic ring on the inner magnetic ring can be used to offset the axial force from the rotor, thereby reducing the axial movement of the rotor, improving the axial stability of the rotor, reducing the friction between the top foil of the first thrust foil bearing and the thrust plate and the friction between the top foil of the second thrust foil bearing and the thrust plate, and improving the durability and performance of the first thrust foil bearing and the second thrust foil bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 The structure of the magnetic hybrid bearing centrifugal compressor of the present application is shown in FIG. Figure 1 ;

[0022] Figure 2 The structure of the magnetic hybrid bearing centrifugal compressor of the present application is shown in FIG. Figure 2 ;

[0023] Figure 3 An exploded view of a magnetic hybrid bearing centrifugal compressor according to an embodiment of the present application;

[0024] Figure 4 A cross-sectional view of a magnetic hybrid bearing centrifugal compressor according to an embodiment of the present application;

[0025] Figure 5 for Figure 4 The enlarged schematic diagram of the middle circle A;

[0026] Figure 6 for Figure 4 The enlarged schematic diagram of the middle circle B;

[0027] Figure 7 The structure of the rotor, stator and housing of the embodiment of the present application is shown in FIG. Figure 1 ;

[0028] Figure 8 The structure of the rotor, stator and housing of the embodiment of the present application is shown in FIG. Figure 2 ;

[0029] Fig. 9 The structure of the rotor, the first radial foil bearing, the first seal, the first impeller and the first pull rod of the embodiment of the present application is schematically shown in FIG. Figure 1 ;

[0030] Fig.10 The structure of the rotor, the first radial foil bearing, the first seal, the first impeller and the first pull rod of the embodiment of the present application is schematically shown in FIG. Figure 2 ;

[0031] Fig.11 The structure of the first end cover, the first connecting member, the diffuser, the first volute and the first flow guide of the embodiment of the present application is schematically shown. Figure 1 ;

[0032] Fig.12 The structure of the first end cover, the first connecting member, the diffuser, the first volute and the first flow guide of the embodiment of the present application is schematically shown. Figure 2 ;

[0033] Fig.13 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 magnetic bearing, the second protective layer, the second impeller and the second pull rod of the embodiment of the present application Figure 1 ;

[0034] Fig.14 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 magnetic bearing, the second protective layer, the second impeller and the second pull rod of the embodiment of the present application Figure 2 ;

[0035] Fig.15 The second end cover, the second connector, the second seal, the second volute and the second flow guide are schematically shown in the embodiment of the present application. Figure 1 ;

[0036] Fig.16 The second end cover, the second connector, the second seal, the second volute and the second flow guide are schematically shown in the embodiment of the present application. Figure 1 ;

[0037] Fig.17 It is a left side view of the thrust plate of the embodiment of the present application;

[0038] Fig.18It is a right side view of the thrust plate of the embodiment of the present application;

[0039] Fig.19 A cross-sectional view of a thrust plate according to an embodiment of the present application;

[0040] Fig. 20 It is a left side view of the permanent magnetic bearing of the embodiment of the present application;

[0041] Fig.21 A cross-sectional view of a permanent magnetic bearing according to an embodiment of the present application;

[0042] Fig. 22 It is a left side view of the thrust plate of the embodiment of the present application;

[0043] Fig.23 It is a right side view of the thrust plate of the embodiment of the present application;

[0044] Fig.24 It is a cross-sectional view of the thrust plate according to the embodiment of the present application.

[0045] The components in the figure are marked as follows:

[0046] 100. Magnetic 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 magnetic bearing; 10. first impeller; 11. second impeller; 12. first seal; 13. first end cover; 14. first connecting piece; 15. diffuser; 16. second end cover; 17. second connecting piece; 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 body; 25. second volute; 26. second guide body;

[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 teeth; 1801, second sealing comb teeth. DETAILED DESCRIPTION

[0053] The preferred embodiments of the present application are described in detail below in conjunction with the drawings in the specification, so as to fully introduce the technical content of the present application to those skilled in the art, to illustrate that the present application can be implemented, to make the technical content disclosed in the present application clearer, and to make it easier for those skilled in the art to understand how to implement the present application. However, the present application can be embodied through many different forms of embodiments, and the protection scope of the present application is not limited to the embodiments mentioned in the text, and the description of the embodiments below is not intended to limit the scope of the present application.

[0054] The directional terms mentioned in this application, such as "up", "down", "front", "back", "left", "right", "inside", "outside", "side", etc., are only directions in the drawings. The directional terms used in this article are used to explain and illustrate this application, and are not used to limit the scope of protection of this application.

[0055] In the drawings, components with the same structure are represented by the same numerical labels, and components with similar structures or functions are represented by similar numerical labels. In addition, for the convenience of understanding and description, the size and thickness of each component shown in the drawings are arbitrarily shown, and the present application does not limit the size and thickness of each component.

[0056] Example 1

[0057] See also Figure 1-Figure 6 The present application provides a magnetic hybrid bearing centrifugal compressor 100. The magnetic hybrid bearing centrifugal compressor 100 includes: 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 plate 7, a second thrust foil bearing 8, a permanent magnetic bearing 9, a first impeller 10, a second impeller 11, a first seal 12, a first end cover 13, a first connecting member 14, a diffuser 15, a second end cover 16, a second connecting member 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 body 24, a second volute 25 and a second guide body 26.

[0058] See also Figure 1-Figure 8 The rotor 1 has a first end 101 and a second end 102 in the axial direction.

[0059] See also Figure 1-Figure 8 , the stator 2 is sleeved in 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, that is, the stator 2 does not rotate with the rotation of the rotor 1.

[0060] See also Figure 1-Figure 8 , the casing 3 is sleeved on the stator 2, and the stator 2 is fixedly connected to the casing 3. Specifically, the outer wall of the stator 2 is fixedly connected to the inner wall of the casing 3.

[0061] See also Figure 1-Figure 6 , Figure 9-10 , the 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] See also Figure 1-Figure 6 , Figure 9-10 , the first seal 12 is sleeved on 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, the 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 close to the rotor 1 is provided with a first sealing comb 1201.

[0063] See also Figure 1-Figure 6 , Figure 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 casing 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] See also Figure 1-Figure 6 , Figure 11-Figure 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] See also Figure 1-Figure 6 , Figure 11-Figure 12 The first connecting member 14 is sleeved on the first radial foil bearing 4 and the first sealing member 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] See also Figure 1-Figure 6 , Figure 11-Figure 12 , the diffuser 15 is sleeved on the first impeller 10 and the first sealing member 12. The diffuser 15 is fixedly connected to the side of the first connecting member 14 away from the casing 3. In this embodiment, the third bolt (not shown) passes through the diffuser 15 and the first connecting member 14 and cooperates with the first end cover 13 to achieve a fixed connection between the diffuser 15, the first connecting member 14 and the first end cover 13.

[0067] See also Figure 1-Figure 6 , Figure 11-Figure 12 The first volute 23 is sleeved on the first connecting member 14, the diffuser 15 and the first impeller 10. The first volute 23 is fixedly connected to the side of the first connecting member 14 away from the casing 3. In this embodiment, the first volute 23 is fixedly connected to the first connecting member 14 by a fourth bolt (not shown).

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

[0069] See also Figure 1-Figure 6 , Figure 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] See also Figure 1-Figure 6 , Figure 13-14 , the 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 side of the second radial foil bearing 5 away from the first end 101 by a first countersunk screw (not shown).

[0071] See also Figure 1-Figure 6 , Figure 13-14 , the thrust plate 7 is sleeved on the second end 102 of the rotor 1. The thrust plate 7 is located on the side of the first thrust foil bearing 6 away from the first end 101. The thrust plate 7 is fixedly connected to the rotor 1. In this embodiment, the thrust plate 7 is fixedly connected to the rotor 1 by a shrink sleeve process.

[0072] See also Figure 17-Figure 19The thrust plate 7 has a first sub-portion 701 and a second sub-portion 702 which are fixedly connected. The second sub-portion 702 is sleeved on the first sub-portion 701, and the thickness of the second sub-portion 702 in the axial direction of the rotor 1 is less than the thickness of the first sub-portion 701 in the axial direction of the rotor 1. The first thrust foil bearing 6 is arranged on a side of the second sub-portion 702 close to the first end 101.

[0073] See also Figure 1-Figure 6 , Figure 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 plate 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 sealing member 18. In this embodiment, the second thrust foil bearing 8 is fixed to the surface of the second sealing member 18 on the side close to the first end 101 by a second countersunk screw (not shown). The second thrust foil bearing 8 is arranged on the side of the second subsection 702 away from the first end 101.

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

[0075] See also Figure 1-Figure 6 , Figure 13-14 , the inner magnetic ring 901 is fixedly connected to the rotor 1. Specifically, the thrust plate 7 at least partially presses against the side of the inner magnetic ring 901 close to the first end 101, and the second impeller 11 at least partially presses against the side of the inner magnetic ring 901 away from the first end 101. Since the second impeller 11 and the thrust plate 7 are both fixedly connected to the rotor 1, the fixed connection between the inner magnetic ring 901, the thrust plate 7 and the second impeller 11 is achieved by pressing the second impeller 11 and the thrust plate 7 against both sides of the inner magnetic ring 901. In this embodiment, the first section 701 of the thrust plate 7 presses against the side of the inner magnetic ring 901 close to the first end 101.

[0076] See also Figure 1-Figure 6 , Figure 13-14 In this embodiment, the first protective layer 19 is disposed on the surface of the inner magnetic ring 901 close to 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 subsection 701 of the thrust plate 7 is pressed against the side of the first protective layer 19 close to the first end 101, and the second impeller 11 is at least partially pressed against the side of the second protective layer 20 away from the first end 101.

[0077] See also Figure 1-Figure 6 , Figure 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 sealing member 18. In this embodiment, the outer magnetic ring 902 is fixedly connected to the second sealing member 18 by adhesive (not shown).

[0078] See also Figure 1-Figure 6 , Figure 13-14 , the second impeller 11 is sleeved on the second end 102 of the rotor 1. The second impeller 11 is located on the side of the permanent magnetic bearing 9 away from the first end 101. The second impeller 11 is fixedly connected to the rotor 1. Specifically, a second through hole 1101 is provided on the second impeller 11, and a second receiving groove 104 is provided on the second end 102 of the rotor 1. One end of the second pull rod 22 abuts against the side of the second impeller 11 away from the casing 3, and the other end of the second pull 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] See also Figure 1-Figure 6 , Figure 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] See also Figure 1-Figure 6 , Figure 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] See also Figure 1-Figure 6 , Figure 15-16 , Figure 21-24 , the second sealing member 18 is sleeved on the permanent magnetic bearing 9. The second sealing member 18 is fixedly connected to the side of the second connecting member 17 away from the housing 3. In this embodiment, the seventh bolt (not shown) passes through the second sealing member 18 and the second connecting member 17 and cooperates with the second end cover 16 to achieve a fixed connection between the second sealing member 18, the second connecting member 17 and the second end cover 16.

[0082] See also Figure 1-Figure 6 , Figure 15-16 , Figure 21-24, the 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 close to 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 close to the second impeller 11 is provided with second sealing comb teeth 1801.

[0083] See also Figure 1-Figure 6 , Figure 15-16 The second volute 25 is sleeved on the second connecting member 17, the second sealing member 18 and the second impeller 11. The second volute 25 is fixedly connected to the side of the second connecting member 17 away from the casing 3. In this embodiment, the second volute 25 is fixedly connected to the second connecting member 17 by an eighth bolt (not shown).

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

[0085] In summary, the magnetic hybrid bearing centrifugal compressor 100 provided in the present application has a permanent magnetic bearing 9 sleeved on the second end 102 of the rotor 1, the inner magnetic ring 901 of the permanent magnetic bearing 9 is fixedly connected to the rotor 1, and the outer magnetic ring 902 of the permanent magnetic bearing 9 is fixedly connected to the casing 3. Therefore, during the start-up and stop process of the magnetic hybrid bearing centrifugal compressor 100, 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 suction 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, thereby reducing the axial movement of the rotor 1, improving the axial stability of the rotor 1, reducing the friction between the top foil of the first thrust foil bearing 6 and the thrust plate 7 and the friction between the top foil of the second thrust foil bearing 8 and the thrust plate 7, and improving the durability and performance of the first thrust foil bearing 6 and the second thrust foil bearing 8. At the same time, the axial force provided by the permanent magnetic bearing 9 is not limited by the rotational speed, and a restoring force is generated only when the rotor 1 produces axial movement and deviates from the equilibrium position. This means that under any operating condition of the magnetic hybrid bearing centrifugal compressor 100, the permanent magnetic bearing 9 can increase the bearing capacity of the original first thrust foil bearing 6 or the upper limit of the bearing capacity of the original second thrust foil bearing 8, which is beneficial 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 description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0087] The above is a detailed introduction to a magnetic hybrid bearing centrifugal compressor provided in an embodiment of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solution and core idea of ​​the present application. Ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the present application.

Claims

1. A magnetic hybrid bearing centrifugal compressor, characterized in that: include: 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 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), 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 a direction from the second end (102) toward 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 plate (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) in a direction from the first end (101) toward 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 plate (7) and the second impeller (11) are all fixedly connected to the rotor (1); The permanent magnetic bearing (9) comprises an inner magnetic ring (901) and an outer magnetic ring (902) which are 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 housing (3).

2. The magnetic hybrid bearing centrifugal compressor according to claim 1, characterized in that: Also includes: a first sealing member (12), sleeved on the first end (101) of the rotor (1) and located between the first impeller (10) and the first radial foil bearing (4), the first sealing member (12) being fixedly connected to the first radial foil bearing (4); a first end cover (13), sleeved on the first end (101) of the rotor (1) and the first radial foil bearing (4), the first end cover (13) being fixedly connected to the casing (3); a first connecting member (14), sleeved on the first radial foil bearing (4) and the first sealing member (12), wherein the first connecting member (14) is fixedly connected to a side of the first end cover (13) away from the housing (3); A diffuser (15) is sleeved on the first impeller (10) and the first sealing member (12), and the diffuser (15) is fixedly connected to a side of the first connecting member (14) away from the casing (3).

3. The magnetic hybrid bearing centrifugal compressor according to claim 2, characterized in that: The first radial foil bearing (4) is fixedly connected to the first connecting member (14).

4. The magnetic hybrid bearing centrifugal compressor according to claim 2, characterized in that: Also includes: A second end cover (16) is sleeved on the second end (102) of the rotor (1) and the second radial foil bearing (5), and the second end cover (16) is fixedly connected to the casing (3); a second connecting member (17), 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) being fixedly connected to a side of the second end cover (16) away from the housing (3); as well as The second sealing member (18) is sleeved on the permanent magnetic bearing (9) and fixedly connected to a side of the second connecting member (17) away from the housing (3).

5. The magnetic hybrid bearing centrifugal compressor according to claim 4, characterized in that: 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 seal (18), and the outer magnetic ring (902) is fixedly connected to the second seal (18).

6. The magnetic hybrid bearing centrifugal compressor according to claim 5, characterized in that: The second seal (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 a side of the second seal (18) close to the first end (101), and the outer magnetic ring (902) is fixedly connected to a side of the second seal (18) away from the first end (101).

7. The magnetic hybrid bearing centrifugal compressor according to claim 5, characterized in that: The outer magnetic ring (902) is fixedly connected to the second sealing member (18) by adhesive.

8. The magnetic hybrid bearing centrifugal compressor according to claim 1, characterized in that: The thrust plate (7) at least partially presses against a side of the inner magnetic ring (901) close to the first end (101), and the second impeller (11) at least partially presses against a side of the inner magnetic ring (901) away from the first end (101).

9. The magnetic hybrid bearing type centrifugal compressor according to claim 8, characterized in that: The thrust plate (7) comprises a first section (701) and a second section (702) which are fixedly connected, the second section (702) being sleeved on the first section (701), and the thickness of the second section (702) in the axial direction of the rotor (1) being smaller than the thickness of the first section (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 section (702), and the first section (701) is pressed against a side of the inner magnetic ring (901) close to the first end (101).

10. The magnetic hybrid bearing centrifugal compressor according to claim 1, characterized in that: Also includes: A first protective layer (19) is disposed on a surface of the inner magnetic ring (901) close to the first end (101); as well as A second protective layer (20) is arranged on a surface of the inner magnetic ring (901) away from the first end (101); The thrust plate (7) at least partially presses against a side of the first protective layer (19) close to the first end (101), and the second impeller (11) at least partially presses against a side of the second protective layer (20) away from the first end (101).

11. The magnetic hybrid bearing centrifugal compressor according to claim 1, characterized in that: The first impeller (10) is provided with a first through hole (1001), the second impeller (11) is provided with a second through hole (1101), the first end (101) of the rotor (1) is provided with a first accommodating groove (103), and the second end (102) of the rotor (1) is provided with a second accommodating groove (104); The magnetic hybrid bearing centrifugal compressor also includes: a first pull rod (21), one end of which abuts against a side of the first impeller (10) away from the housing (3), and the other end of which 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); and A second pull rod (22) has one end abutting against a side of the second impeller (11) away from the casing (3), and the other end thereof 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).

12. The magnetic hybrid bearing centrifugal compressor according to claim 4, characterized in that: Also includes: a first volute (23), which is sleeved on the first connecting member (14), the diffuser (15) and the first impeller (10), and is fixedly connected to a side of the first connecting member (14) away from the casing (3); A first flow guide (24) is sleeved on the first impeller (10) and fixedly connected to the first volute (23); A second volute (25) is sleeved on the second connecting member (17), the second sealing member (18) and the second impeller (11), and is fixedly connected to a side of the second connecting member (17) away from the casing (3); The second flow guide (26) is sleeved on the second impeller (11) and fixedly connected to the second volute (25).

13. The magnetic hybrid bearing centrifugal compressor according to claim 2, characterized in that: The first seal (12) comprises a labyrinth seal, and a surface of the first seal (12) on a side close to the rotor (1) is provided with first sealing comb teeth (1201).

14. The magnetic hybrid bearing type centrifugal compressor according to claim 4, characterized in that: The second sealing member (18) comprises a labyrinth seal, and a surface of the second sealing member (18) on a side close to the second impeller (11) is provided with second sealing comb teeth (1801).

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