Centrifugal compressor

Abstract

The present application relates to a kind of centrifugal compressor, including shell, rotor, inner magnetic ring and outer magnetic ring, the rotor is arranged in the shell, the inner magnetic ring is arranged on the rotor, the outer magnetic ring is arranged on the shell, the outer magnetic ring is sleeved on the inner magnetic ring and with the inner magnetic ring in the radial direction of the rotor with gap, the inner circumferential surface of the outer magnetic ring and the outer circumferential surface of the inner magnetic ring on pole opposite.The centrifugal compressor of the present application, when the rotor bears external axial force, the axial force received by the rotor is balanced by the magnetic attraction force between the inner magnetic ring and the outer magnetic ring, at least part of the axial force acting on the rotor is cancelled, to avoid dry grinding of the gas floating thrust bearing on the rotor, reduce the heating condition of the gas floating thrust bearing, ensure the stability of the rotor under different working conditions of centrifugal compressor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of compressors, in particular to a centrifugal compressor. BACKGROUND

[0002] Dynamic pressure gas bearing is widely used in air circulating machine, micro gas turbine, industrial air blower and compressor field. Radial gas bearing is used as support in occasions requiring clean air source, but there is often unbalanced axial force in air compressor, so the matched bearing is gas floating thrust bearing, which carries axial force. However, in actual assembly, there are some situations that do not conform to theoretical calculation, overload, stator assembly cannot be absolutely concentric with the shaft and so on. Since the gas floating thrust bearing can form effective gas mode at a certain speed, before the formation of gas mode, the gas floating thrust bearing is in dry grinding state, which causes dry grinding between the gas floating thrust bearing and the bearing bush during start-up or overload, which is irreversible damage to the gas floating thrust bearing, reduces the service life of the gas floating thrust bearing, and even directly damages the bearing in severe cases. SUMMARY

[0003] The present application aims to at least solve one of the technical problems in the related art. To this end, an embodiment of the present application proposes a centrifugal compressor, which avoids dry grinding of the gas floating thrust bearing on the rotor, reduces the heating of the gas floating thrust bearing, and ensures the stability of the rotor under different working conditions of the centrifugal compressor.

[0004] The centrifugal compressor of the embodiment of the present application comprises:

[0005] a casing;

[0006] a rotor provided in the casing;

[0007] an inner magnetic ring provided on the rotor; and

[0008] an outer magnetic ring provided on the casing, the outer magnetic ring being sleeved on the inner magnetic ring and having a gap with the inner magnetic ring in the radial direction of the rotor, and the magnetic poles on the inner periphery of the outer magnetic ring and the outer periphery of the inner magnetic ring being opposite.

[0009] When the rotor of the centrifugal compressor of the embodiment of the present application bears external axial force, the magnetic attraction force between the inner magnetic ring and the outer magnetic ring balances the axial force received by the rotor, cancels at least part of the axial force acting on the rotor, avoids dry grinding of the gas floating thrust bearing on the rotor, reduces the heating of the gas floating thrust bearing, and ensures the stability of the rotor under different working conditions of the centrifugal compressor.

[0010] In some embodiments, each of the inner magnetic ring and the outer magnetic ring is axially magnetized.

[0011] In some embodiments, the inner magnetic ring has a first radial cross section at the center of its axial direction, the magnetic poles of the inner magnetic ring on both sides of the first radial cross section in its axial direction are opposite; the outer magnetic ring has a second radial cross section at the center of its axial direction, the magnetic poles of the outer magnetic ring on both sides of the second radial cross section in its axial direction are opposite.

[0012] In some embodiments, the first radial cross section and the second radial cross section are spaced apart in the axial direction of the rotor.

[0013] In some embodiments, the size of the inner magnetic ring in its axial direction is different from the size of the outer magnetic ring in its axial direction.

[0014] In some embodiments, the casing comprises a shell, a first machine cover and a second machine cover, the first machine cover is located on one side of the shell, one end of the rotor in its axial direction is rotationally connected with the first machine cover, the second machine cover is located on the other side of the shell, the other end of the rotor in its axial direction is rotationally connected with the second machine cover, the outer magnetic ring is arranged on the first machine cover and / or the second machine cover, the outer magnetic ring has a second radial cross section at the center of its axial direction;

[0015] The rotor comprises a magnetic steel, the magnetic steel has a third radial cross section at the center of its axial direction, the magnetic steel is spaced apart from the inner magnetic ring in its axial direction, the inner magnetic ring has a first radial cross section at the center of its axial direction;

[0016] The centrifugal compressor further comprises a stator, the stator is installed in the shell, the stator is sleeved on the rotor and has a gap with the rotor in its radial direction, the stator has a fourth radial cross section at the center of its axial direction, the third radial cross section is spaced apart from the fourth radial cross section, the offset direction of the third radial cross section and the fourth radial cross section is the same as the offset direction of the first radial cross section and the second radial cross section, or the first radial cross section and the second radial cross section are on the same plane.

[0017] In some embodiments, the centrifugal compressor further comprises:

[0018] a first turbine, the first turbine has a first volute and a first impeller, the first volute is arranged on the first machine cover, and the first impeller is arranged on the rotor; and

[0019] a first gasket, the first gasket is arranged between the first volute and the first machine cover and / or between the first machine cover and the shell.

[0020] In some embodiments, the centrifugal compressor further comprises:

[0021] a second turbine having a second volute and a second impeller, the second volute being provided on the second cover, the second impeller being provided on the rotor; and

[0022] a second gasket provided between the second cover and the casing and / or between the second cover and the second volute.

[0023] In some embodiments, the first cover is integrally formed with the casing, and the first gasket is provided between the first volute and the first cover.

[0024] In some embodiments, the centrifugal compressor further comprises an aerodynamic thrust bearing provided on the rotor. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a structural schematic diagram of a primary centrifugal compressor according to an embodiment of the present application.

[0026] Figure 2 is one of the schematic diagrams of an inner magnetic ring and an outer magnetic ring;

[0027] Figure 3 is the other of the schematic diagrams of an inner magnetic ring and an outer magnetic ring;

[0028] Figure 4 is a structural schematic diagram of a secondary centrifugal compressor according to an embodiment of the present application.

[0029] REFERENCE SIGNS

[0030] centrifugal compressor 100;

[0031] casing 1, casing 11, first cover 12, second cover 13;

[0032] rotor 2, magnetic steel 21, third radial cross section 211;

[0033] inner magnetic ring 3, first radial cross section 31, outer magnetic ring 4, second radial cross section 41, stator 5, fourth radial cross section 51, first gasket 71, second gasket 72, first turbine 8, first volute 81, first impeller 82, second turbine 9, second volute 91, second impeller 92, aerodynamic thrust bearing 10. DETAILED DESCRIPTION

[0034] Embodiments of the present application are described in detail below with reference to the attached drawings. The embodiments described below are examples of the present application, and are intended to explain the present application, and should not be understood as limiting the present application.

[0035] As Figures 1 to 4As shown, the centrifugal compressor 100 of this embodiment includes a housing 1, a rotor 2, an inner magnetic ring 3, and an outer magnetic ring 4. The rotor 2 is disposed inside the housing 1, the inner magnetic ring 3 is disposed on the rotor 2, and the outer magnetic ring 4 is disposed on the housing 1. The outer magnetic ring 4 is sleeved on the inner magnetic ring 3 and has a gap with the inner magnetic ring 3 in the radial direction of the rotor 2. The magnetic poles on the inner circumferential surface of the outer magnetic ring 4 and the outer circumferential surface of the inner magnetic ring 3 are opposite.

[0036] The inner circumferential surface of the inner magnetic ring 3 and the outer circumferential surface of the outer magnetic ring 4 have opposite magnetic poles. The magnetic pole distribution of the inner magnetic ring 3 and the outer magnetic ring 4 includes the following cases: ① Each of the inner magnetic ring 3 and the outer magnetic ring 4 is radially magnetized, for example, see [reference missing]. Figure 2 ① The outer circumferential surface of the inner magnetic ring 3 is the N pole, and the inner circumferential surface of the outer magnetic ring 4 is the S pole. Correspondingly, the inner circumferential surface of the inner magnetic ring 3 is the S pole, and the outer circumferential surface of the outer magnetic ring 4 is the N pole. ② Each of the inner magnetic ring 3 and the outer magnetic ring 4 is axially magnetized. For example, referring to Figure 3, one end (left end) of the inner magnetic ring 3 in the axial direction of the rotor 2 is the N pole, and the other end (right end) of the inner magnetic ring 3 in the axial direction of the rotor 2 is the S pole. One end (left end) of the outer magnetic ring 4 in the axial direction of the rotor 2 is the S pole, and the other end (left end) of the outer magnetic ring 4 in the axial direction of the rotor 2 is the N pole.

[0037] In this embodiment of the centrifugal compressor 100, the magnetic poles on the inner circumferential surface of the outer magnetic ring 4 and the outer circumferential surface of the inner magnetic ring 3 are opposite, resulting in a force on the inner magnetic ring 3 towards the outer magnetic ring 4, and a force on the outer magnetic ring 4 towards the inner magnetic ring 3. The inner magnetic ring 3 and the outer magnetic ring 4 attract each other. When the rotor 2 is subjected to an external axial force and shifts in its axial direction, it will cause the inner magnetic ring 3 to shift, changing the relative position of the inner magnetic ring 3 and the outer magnetic ring 4. The force formed on the inner magnetic ring 3 in the axial direction of the rotor 2 towards the outer magnetic ring 4 balances the axial force that causes the rotor 2 to shift, driving the inner magnetic ring 3 to reset, that is, driving the rotor 2 to reset, thus preventing dry friction of the air-bearing thrust bearing on the rotor 2.

[0038] In the centrifugal compressor 100 of this embodiment, when the rotor 2 is subjected to external axial force, the magnetic attraction between the inner magnetic ring 3 and the outer magnetic ring 4 balances the axial force on the rotor 2, offsetting at least a portion of the axial force acting on the rotor 2, preventing dry friction of the air-floating thrust bearing on the rotor 2, reducing the heat generation of the air-floating thrust bearing, and ensuring the stability of the rotor 2 under different operating conditions of the centrifugal compressor 100.

[0039] To make the scheme of this application easier to understand, the example given is that the axial direction of rotor 2 is the same as the left-right direction, where the left-right direction is as follows: Figures 1 to 4 As shown.

[0040] The centrifugal compressor 100 of the embodiment of the application comprises a casing 1, a rotor 2, an inner magnetic ring 3, an outer magnetic ring 4, a stator 5, a first turbine 8, a first gasket 71 and an air floating thrust bearing 10.

[0041] The casing 1 comprises a housing 11, a first casing cover 12 and a second casing cover 13, the first casing cover 12 is located at one side (left side) of the housing 11, and the rotor 2 is rotationally connected to the first casing cover 12 at one end (left end) in the axial direction of the rotor 2, and the second casing cover 13 is located at the other side (right side) of the housing 11, and the rotor 2 is rotationally connected to the second casing cover 13 at the other end (right end) in the axial direction of the rotor 2.

[0042] The rotor 2 comprises a magnetic steel 21, the magnetic steel 21 has a third radial cross section 211 at the center in the axial direction of the magnetic steel 21, and the center in the axial direction of the magnetic steel 21 is located on the third radial cross section 211 of the magnetic steel 21.

[0043] The air floating thrust bearing 10 is arranged on the rotor 2 to counteract at least part of the axial force borne by the rotor 2, and balance the axial force borne by the rotor 2.

[0044] The inner magnetic ring 3 is arranged on the rotor 2, and the magnetic steel 21 is spaced apart from the inner magnetic ring 3 in the axial direction, and the outer magnetic ring 4 is arranged on the casing 1, the outer magnetic ring 4 is sleeved on the inner magnetic ring 3 and has a gap with the inner magnetic ring 3 in the radial direction of the rotor 2, the magnetic poles on the inner periphery of the outer magnetic ring 4 and the outer periphery of the inner magnetic ring 3 are opposite, and the inner magnetic ring 3 and the outer magnetic ring 4 are attracted to each other.

[0045] Further, the first casing cover 12 is provided with the outer magnetic ring 4, and the inner magnetic ring 3 is located at the one end of the rotor 2. Alternatively, the second casing cover 13 is provided with the outer magnetic ring 4, and the inner magnetic ring is located at the other end of the rotor 2, as shown in Figure 1 Alternatively, each of the first casing cover 12 and the second casing cover 13 is provided with the outer magnetic ring 4, and correspondingly, each of the one end and the other end of the rotor 2 is provided with the inner magnetic ring 3, which further improves the size of the axial force borne by the rotor 2 that can be counteracted, and further improves the stability of the rotor 2.

[0046] The inner magnetic ring 3 and the outer magnetic ring 4 are simple to process, and the distribution of the inner magnetic ring 3 on the rotor 2 and the distribution position of the outer magnetic ring 4 on the casing 1 are selectively multiple and have good flexibility and adaptability.

[0047] In some embodiments, each of the inner magnetic ring 3 and the outer magnetic ring 4 is axially magnetized. The magnetic pole distribution of each of the inner magnetic ring 3 and the outer magnetic ring 4 is distributed along the axial direction, which can generate a larger axial magnetic attraction force, and has a good effect of balancing the axial force on the rotor 2. Compared with a radially magnetized magnetic ring manufactured by using magnetic powder and plastic injection molding, the axially magnetized inner magnetic ring 3 and the outer magnetic ring 4 can use a wider range of materials, are easy to manufacture, and can generate a larger axial magnetic attraction force when the material of the inner magnetic ring 3 and the outer magnetic ring 4 has a large residual magnetism, such as platinum-iron permanent magnetic alloy.

[0048] The magnetic attraction force between the axially magnetized inner magnetic ring 3 and the outer magnetic ring 4 is large. In some embodiments, the inner magnetic ring 3 has a first radial cross section 31 at the center of the axial direction of the inner magnetic ring 3, the center of the axial direction of the inner magnetic ring 3 is located on the first radial cross section 31 of the inner magnetic ring 3, and the magnetic poles of the inner magnetic ring 3 on both sides of the first radial cross section 31 in the axial direction of the inner magnetic ring 3 are opposite, that is, the inner magnetic ring 3 has a pair of magnetic poles, and the boundary line of the two magnetic poles on the inner magnetic ring 3 is on the first radial cross section 31 of the inner magnetic ring 3. The outer magnetic ring 4 has a second radial cross section 41 at the center of the axial direction of the outer magnetic ring 4, the center of the axial direction of the outer magnetic ring 4 is located on the second radial cross section 41 of the outer magnetic ring 4, and the magnetic poles of the outer magnetic ring 4 on both sides of the second radial cross section 41 in the axial direction of the outer magnetic ring 4 are opposite, that is, the outer magnetic ring 4 has a pair of magnetic poles, and the boundary line of the two magnetic poles on the outer magnetic ring 4 is on the second radial cross section 41 of the outer magnetic ring 4. The structure of the inner magnetic ring 3 and the outer magnetic ring 4 is simple, and the cost is low.

[0049] In some embodiments, the first radial cross section 31 and the second radial cross section 41 are spaced apart in the axial direction of the rotor 2, and the axial magnetic attraction force between the inner magnetic ring 3 and the outer magnetic ring 4 can offset the axial force acting on the rotor 2 of the corresponding size, thereby balancing the axial force on the rotor 2, so that the radial design size of the gas floating thrust bearing 10 can be reduced, the loss of the gas floating thrust bearing 10 can be reduced, and the heating of the gas floating thrust bearing 10 can be reduced.

[0050] In Figure 1 and Figure 3 In the direction shown, when the first radial cross section 31 is shifted to the right, the first radial cross section 31 is located to the right of the second radial cross section 41, and the magnetic attraction force on the inner magnetic ring 3 is to the left, and when the first radial cross section 31 is shifted to the left, the first radial cross section 31 is located to the left of the second radial cross section 41, and the magnetic attraction force on the inner magnetic ring 3 is to the right.

[0051] Specifically, refer to Figure 1When the outer magnetic ring 4 is located on the second cover 13 and the inner magnetic ring is located at the other end of the rotor 2, when the first radial cross section 31 is located on the side of the second radial cross section 41 away from the first cover 12 (the first radial cross section 31 is located on the right side of the second radial cross section 41), the magnetic attraction force on the inner magnetic ring 3 is towards the first cover 12 and towards the left. When the first radial cross section 31 is located on the side of the second radial cross section 41 adjacent to the first cover 11 (the first radial cross section 31 is located on the left side of the second radial cross section 41), the magnetic attraction force on the inner magnetic ring 3 is towards the second cover 13 and towards the right.

[0052] In some embodiments, the inner magnetic ring 3 has a different axial dimension than the outer magnetic ring 4, which can adapt to different structural layouts on the rotor 2 and the housing 1 (the first cover 12 and / or the second cover 13 of the housing 1), and has good applicability.

[0053] Specifically, the first radial cross-section 31 of the inner magnetic ring 3 and the second radial cross-section 41 of the outer magnetic ring 4 are located on the same plane. The axial dimension of the inner magnetic ring 3 is smaller than that of the outer magnetic ring 4, resulting in a smaller space occupied by the inner magnetic ring 3 on the rotor 2, which helps the rotor 2 maintain a relatively compact structural layout. Correspondingly, the axial dimension of the outer magnetic ring 3 is smaller than that of the inner magnetic ring 3, which helps the housing 1 (the first cover 12 and / or the second cover 13 of the housing 1) maintain a relatively compact structural layout. Furthermore, when the first radial cross-section 31 of the inner magnetic ring 3 and the second radial cross-section 41 of the outer magnetic ring 4 are spaced apart axially on the rotor 2, it not only helps the rotor 2 or the housing 1 maintain a relatively compact structural layout, but also balances at least a portion of the axial force on the rotor 2.

[0054] The stator 5 is installed inside the housing 11. The stator 5 is sleeved on the rotor 2 and has a gap with the rotor 2 in its radial direction. The stator 5 has a fourth radial cross section 51 at its axial center, and the axial center of the stator 5 is located on the fourth radial cross section 51 of the stator 5.

[0055] In some embodiments, the third radial cross section 211 and the fourth radial cross section 51 are spaced apart axially from the rotor 2. In the centrifugal compressor 100 of the related art, the radial cross section at the center of the rotor in its axial direction coincides with the radial cross section at the center of the stator in its axial direction, and there is no axial force between them. However, in the centrifugal compressor 100 of the present invention, the magnet 21 is arranged in a staggered manner with the stator 5, thereby generating a magnetic pull force in the axial direction of the rotor 2, thereby balancing the axial force acting on the rotor 2.

[0056] The direction and magnitude of the magnetic pull can be adjusted by adjusting the offset direction and offset distance of the magnet 21.

[0057] SeeFigure 1 When the first radial cross section 31 and the second radial cross section 41 are located on the same plane, when the third radial cross section 211 is located on the side of the fourth radial cross section 51 away from the second cover 13 in the axial direction of the rotor 2 (the third radial cross section 211 is located on the left side of the fourth radial cross section 51), the magnetic pull generated is towards the second cover 13, the magnetic pull is to the right. When the third radial cross section 211 is located on the side of the fourth radial cross section 51 away from the first cover 12 in the axial direction of the rotor 2 (the third radial cross section 211 is located on the right side of the fourth radial cross section 51), the magnetic pull generated is towards the first cover 12, the magnetic pull is to the left.

[0058] In some other embodiments, the offset direction of the third radial cross section 211 and the fourth radial cross section 51 is the same as the offset direction of the first radial cross section 31 and the second radial cross section 41, the direction of the magnetic pull formed on the magnetic steel 21 is the same as the direction of the magnetic attraction formed on the inner magnetic ring 3, so that the magnetic pull and the magnetic attraction can be superimposed, further improving the axial force that the rotor 2 can offset, thereby further reducing the size of the air floating thrust bearing 10.

[0059] For example, in the direction shown in FIGS. 1-3, the first radial cross section 31 is located on the left side of the second radial cross section 41, the magnetic attraction generated is to the right, the third radial cross section 211 is located on the left side of the fourth radial cross section 51, the magnetic attraction generated is to the right, the magnetic attraction and the magnetic pull are superimposed, and the axial force acting on the rotor 2 is balanced. Alternatively, the first radial cross section 31 is located on the right side of the second radial cross section 41, the magnetic attraction generated is to the left, the third radial cross section 211 is located on the right side of the fourth radial cross section 51, the magnetic attraction generated is to the left, the magnetic attraction and the magnetic pull are superimposed, and the axial force acting on the rotor 2 is balanced. Figure 1 Figure 3 Figure 4

[0060] In some embodiments, the first turbine 8 has a first volute 81 and a first impeller 82, the first volute 81 is arranged on the first cover 12, and the first impeller 82 is arranged on the rotor 2, the first impeller 82 is arranged on the one end of the rotor 2, and the centrifugal compressor 100 of the embodiment of the present application is a single-stage compressor. The first gasket 71 is arranged between the first volute 81 and the first cover 12 and / or between the first cover 12 and the shell 11.

[0061] ​​​When the first gasket 71 is added between the first volute 81 and the first cover 12, the distance between the first volute 81 and the shell 11 in the axial direction of the rotor 2 is increased, and when the first gasket 71 is added between the first cover 12 and the shell 11, the distance between each of the first volute 81 and the first cover 12 and the shell 11 in the axial direction of the rotor 2 is increased, the end of the rotor 2 is moved in the direction away from the second cover 13 (that is, to the left), the third radial cross section 211 of the magnetic steel 21 is offset in the direction of the first cover 12 (that is, to the left), and the direction of the generated magnetic pull is toward the second cover 13 (that is, the direction of the magnetic pull is to the right).

[0062] Alternatively, when the thickness of the first gasket 71 between the first volute 81 and the first cover 12 and / or between the first cover 12 and the shell 11 is m, the third radial cross section 211 of the magnetic steel 21 is located in the same plane as the fourth radial cross section 51 of the stator 5, if the thickness of the first gasket 71 is adjusted to increase the value of m, the end of the rotor 2 is moved in the direction away from the second cover 13 (that is, to the left), the third radial cross section 211 of the magnetic steel 21 is offset in the direction away from the second cover 13 (that is, to the left), and the direction of the generated magnetic pull is toward the second cover 13 (that is, the direction of the magnetic pull is to the right). If the thickness of the first gasket 71 is adjusted to decrease the value of m, the end of the rotor 2 is moved in the direction toward the second cover 13 (that is, to the right), the third radial cross section 211 of the magnetic steel 21 is offset in the direction toward the second cover 13 (that is, to the right), and the direction of the generated magnetic pull is away from the second cover 13 (that is, the direction of the magnetic pull is to the left).

[0063] The centrifugal compressor 100 of the embodiment of the present application adjusts the thickness of the first gasket 71, thereby adjusting the misalignment distance and offset direction of the magnetic steel 21, and then adjusting the size and direction of the magnetic pull.

[0064] Further, the first cover 12 is integrally formed with the shell 11, and the first gasket 71 is arranged between the first volute 81 and the first cover 12.

[0065] In some embodiments, the centrifugal compressor 100 further comprises a second turbine 9 and a second gasket 72, the second turbine 9 has a second volute 91 and a second impeller 92, the second volute 91 is arranged on the second cover 13, and the second impeller 92 is arranged on the rotor 2, and the second impeller 92 is located on the other end of the rotor 2. The centrifugal compressor 100 of the embodiment of the present application is a two-stage compressor, as shown in Figure 4 .

[0066] The second gasket 72 is arranged between the second cover 13 and the shell 11 and / or between the second cover 13 and the second volute 91.

[0067] When the thickness of the first gasket 71 between the first volute 81 and the first cover 12 is m', and the thickness of the second gasket 72 between the second cover 13 and the shell 11 and / or between the second cover 13 and the second volute 91 is n, the third radial cross section 211 of the magnetic steel 21 and the fourth radial cross section 51 of the stator 5 are located in the same plane.

[0068] If the thickness of the first gasket 71 is adjusted to increase the value of m' by x, the one end of the rotor 2 is driven to move away from the direction of the second cover 13 (that is, to the left), the third radial cross section 211 of the magnetic steel 21 is offset away from the direction of the second cover 13 (that is, to the left), the direction of the magnetic pull generated is towards the second cover 13 (that is, the direction of the magnetic pull is to the right), and the thickness of the second gasket 72 is reduced by x, then the second volute 91 and the second impeller 92 move towards the direction of the first cover 12, so that the assembly gap between the second volute 91 and the second impeller 92 and / or the assembly position of the other end of the rotor 2 and the second impeller 92 can be avoided from changing.

[0069] If the thickness of the first gasket 71 is adjusted to reduce the value of m by y, and the thickness of the second gasket 72 is increased by y, then the one end of the rotor 2 is driven to move towards the direction of the second cover 13 (that is, to the right), and the direction of the magnetic pull generated is away from the second cover 13 (that is, the direction of the magnetic pull is to the left).

[0070] The centrifugal compressor 100 of the embodiment of the present application realizes the offset of the magnetic steel 21 by arranging the first gasket 71 and the second gasket 72, compared with the way of directly changing the position of the magnetic steel on the rotor to realize the deflection of the magnetic steel, the first gasket 71 and the second gasket 72 are simple to manufacture and low in processing cost, different thicknesses of gaskets can be produced in batches, the centrifugal compressor 100 is convenient for quick assembly, the offset amount of the magnetic steel 33 of the centrifugal compressor 100 can be accurately controlled, the applicability is strong, the structure and size of the rotor are little changed, the production cost of the centrifugal compressor 100 can be reduced, and the production efficiency of the centrifugal compressor 100 can be improved.

[0071] In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0072] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0073] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0074] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," or "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature.

[0075] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments and features of different embodiments or examples described in this specification.

[0076] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A centrifugal compressor, characterized in that, include: Casing (1); Rotor (2), the rotor (2) is disposed inside the housing (1); An inner magnetic ring (3) is disposed on the rotor (2); and An outer magnetic ring (4) is disposed on the housing (1). The outer magnetic ring (4) is sleeved on the inner magnetic ring (3) and has a gap with the inner magnetic ring (3) in the radial direction of the rotor (2). The magnetic poles of the inner circumferential surface of the outer magnetic ring (4) and the outer circumferential surface of the inner magnetic ring (3) are opposite. The housing (1) includes a housing (11), a first cover (12) and a second cover (13). The first cover (12) is located on one side of the housing (11). The rotor (2) is rotatably connected to the first cover (12) at one end in its axial direction. The second cover (13) is located on the other side of the housing (11). The rotor (2) is rotatably connected to the second cover (13) at the other end in its axial direction. The first cover (12) and / or the second cover (13) are provided with the outer magnetic ring (4). The outer magnetic ring (4) has a second radial cross section at its center in its axial direction. The rotor (2) includes a magnet (21) having a third radial cross section at its center in the axial direction, the magnet (21) being spaced apart from the inner magnetic ring (3) in the axial direction, the inner magnetic ring (3) having a first radial cross section at its center in the axial direction; The centrifugal compressor further includes a stator (5) which is installed inside the housing (11). The stator (5) is sleeved on the rotor (2) and has a gap in its radial direction with respect to the rotor (2). The stator (5) has a fourth radial cross section at its center in its axial direction. The third radial cross section is spaced apart from the fourth radial cross section. The offset direction of the third radial cross section from the fourth radial cross section is the same as the offset direction of the first radial cross section from the second radial cross section. Alternatively, the first radial cross section and the second radial cross section are on the same plane.

2. The centrifugal compressor according to claim 1, characterized in that, Each of the inner magnetic ring (3) and the outer magnetic ring (4) is axially magnetized.

3. The centrifugal compressor according to claim 2, characterized in that, The inner magnetic ring (3) has a first radial cross-section at its center in its axial direction, and the magnetic poles of the inner magnetic ring (3) located on both sides of the first radial cross-section in its axial direction are opposite; the outer magnetic ring (4) has a second radial cross-section at its center in its axial direction, and the magnetic poles of the outer magnetic ring (4) located on both sides of the second radial cross-section in its axial direction are opposite.

4. The centrifugal compressor according to claim 3, characterized in that, The first radial cross section and the second radial cross section are spaced apart axially in the rotor (2).

5. The centrifugal compressor according to claim 3 or 4, characterized in that, The inner magnetic ring (3) has a different axial dimension than the outer magnetic ring (4).

6. The centrifugal compressor according to claim 1, characterized in that, Further includes: A first turbine (8) having a first volute (81) and a first impeller (82), the first volute (81) being disposed on the first cover (12) and the first impeller (82) being disposed on the rotor (2); and A first gasket (71) is disposed between the first volute (81) and the first cover (12) and / or between the first cover (12) and the housing (11).

7. The centrifugal compressor according to claim 6, characterized in that, Further includes: The second turbine (9) has a second volute (91) and a second impeller (92), the second volute (91) being disposed on the second cover (13) and the second impeller (92) being disposed on the rotor (2); and The second gasket (72) is disposed between the second cover (13) and the housing (11) and / or between the second cover (13) and the second volute (91).

8. The centrifugal compressor according to claim 6, characterized in that, The first cover (12) is integrally formed with the housing (11), and the first gasket (71) is disposed between the first volute (81) and the first cover (12).

9. The centrifugal compressor according to claim 1, characterized in that, It further includes an air-floating thrust bearing (10) disposed on the rotor (2).

Images