Volute assembly and compressor

Abstract

According to the volute assembly and the compressor, the volute assembly has the radial direction and the axial direction, at least two compression cavities which are sequentially arranged in the axial direction are defined by the volute assembly, each compression cavity comprises an air inlet channel, an air collection chamber and a pressurization chamber which are sequentially communicated, and the pressurization chambers are used for containing impellers; the air inlet channel in at least one compression cavity extends in the radial direction, and at least part of the air inlet channel is overlapped with the air collecting chamber in the radial direction. According to the volute assembly, the air inlet channel does not occupy axial space, the axial distance between every two adjacent compression cavities can be shortened, and the axial size of the whole volute assembly is remarkably reduced. The axial size of the volute assembly is shortened, and conditions can be directly created for shortening the axial length of the rotor shaft. After the axial length of the rotor is shortened, the rigidity of the rotor shaft can be enhanced, the first-order bending mode frequency is improved, the resonance risk is reduced, and the operation stability of the high-speed magnetic suspension rotor is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of air compressor equipment, and in particular to a volute assembly and a compressor. Background Art

[0002] Magnetic levitation centrifugal compressors are widely used in the industrial field, mainly including magnetic levitation centrifugal refrigeration compressors, magnetic levitation air compressors, magnetic levitation blowers and other high-speed rotating machinery.

[0003] Magnetic bearings, due to their advantages such as high speed, oil-free operation, energy saving, and low noise, have been gradually applied in turbine machinery, vacuum cleaning, flywheel energy storage, and other fields. For high-speed magnetic levitation rotors, due to the rigid rotor constraints, it is necessary to minimize the rotor axial length, increase the first-order bending mode frequency, and improve rotor stability.

[0004] The volute assembly and intake casing of a magnetic levitation compressor or air compressor are the main pneumatic components. In the traditional multi-stage compression structure of a compressor, the chambers of each compression structure are axially inlet. The axial intake structure occupies the axial length of the air compressor, making it impossible to further reduce the axial length of the rotor shaft. Summary of the Invention

[0005] The purpose of the present invention is to solve the problem of at least the axial length of the air compressor occupied by the axial air intake structure. This purpose is achieved by the following means:

[0006] A first aspect of the present invention proposes a volute assembly, which has a radial and axial direction, and defines a first compression chamber and a second compression chamber arranged in sequence along the axial direction, the first compression chamber includes a first air inlet duct, a first air collecting chamber and a first pressure chamber connected in sequence, the first pressure chamber is used to accommodate a first impeller, the second compression chamber includes a second air inlet duct, a second air collecting chamber and a second pressure chamber connected in sequence, the second pressure chamber is used to accommodate a second impeller; wherein, at least one of the first air inlet duct and the second air inlet duct extends along a first direction, and the first direction is parallel to the radial direction or forms an angle less than 90° with the radial direction.

[0007] According to the volute assembly of the present invention, the first or second air inlet duct extends radially. Compared to extending axially, this can reduce the length of the axial space occupied, shorten the axial spacing between two adjacent compression chambers, and significantly reduce the axial size of the entire volute assembly. Shortening the axial size of the volute assembly directly creates conditions for shortening the axial length of the rotor shaft. When the axial length of the rotor is shortened, the rigidity of the rotor shaft can be enhanced, the first-order bending modal frequency can be increased, the risk of resonance can be reduced, and the operational stability of the high-speed magnetic levitation rotor can be significantly improved.

[0008] In addition, the volute assembly according to the present invention may also have the following additional technical features:

[0009] In some embodiments of the present invention, the volute assembly includes a connected volute and a first air inlet housing;

[0010] The volute defines the first air inlet duct, the first air inlet housing defines the first air collecting chamber, and the volute and the first air inlet housing jointly define the first pressurized chamber; the first air collecting chamber is communicated with the first pressurized chamber at one end along the axial direction, the first air inlet duct passes through the inner circumferential wall of the first air collecting chamber, the first air inlet duct extends along the radial direction, and at least part of the first air inlet duct overlaps with the first air collecting chamber along the radial direction.

[0011] In some embodiments of the present invention, the first air collecting chamber and the first pressurized chamber have a connecting port, the first air inlet duct is provided with a first air inlet at one end radially away from the first air collecting chamber, the connecting port has a first axis, the first air inlet duct has a second axis, the first axis is parallel to the axial direction, and the first axis intersects with the second axis.

[0012] In some embodiments of the present invention, the volute assembly further includes a diverter rib extending along the second axis, wherein the diverter rib is located in the compression chamber and is provided between the communication port and the first air inlet.

[0013] In some embodiments of the present invention, the volute assembly further includes at least one guide rib, which is disposed in the first air collecting chamber and outside the connecting port around the first axis. The guide rib is inclined relative to the second axis, and the first end of the guide rib extends to the circumferential edge of the connecting port. Along the direction of the second axis, the distance from the second end of the guide rib to the first air inlet is smaller than the distance from the first end to the first air inlet.

[0014] In some embodiments of the present invention, the guide ribs are respectively provided on both sides of the communication port along a first direction, and the first direction is perpendicular to the first axis and the second axis respectively.

[0015] In some embodiments of the present invention, the guide rib has a first guide surface facing the first air inlet and a second guide surface opposite to the first guide surface, the first guide surface is a concave curved surface, and the second guide surface is a convex curved surface; and / or, from the radial outside to the radial inside of the first air collecting chamber, the thickness of the guide rib first increases and then decreases.

[0016] In some embodiments of the present invention, the circumferential inner wall of the first air collecting chamber is further provided with a guide surface, and along the extension direction of the second axis, the guide surface is located on the side of the first axis away from the first air inlet; along the direction from the first air inlet to the connecting port, the radial spacing between the guide surface and the circumferential edge of the connecting port gradually decreases.

[0017] In some embodiments of the present invention, the guide surface includes a first guide surface and a second guide surface, and the first guide surface and the second guide surface are symmetrically arranged with the second axis as a symmetry axis.

[0018] In some embodiments of the present invention, along the circumference of the first air collecting chamber, the guide surface has a head end and a tail end, the head end is closer to the first air inlet duct than the tail end, the head end is smoothly connected to the circumferential inner wall of the first air collecting chamber, the tail end extends to the circumferential edge of the connecting port, and the tail end intersects with the second axis.

[0019] In some embodiments of the present invention, the volute includes a main body and a first volute portion connected to one end of the main body along the axial direction, the first volute portion defines a first volute chamber, the first volute chamber is circumferentially arranged outside the first pressurized chamber, and the first volute chamber is communicated with the exhaust end of the first pressurized chamber;

[0020] The first volute portion has an inner circumferential wall arranged around the first axis, the inner circumferential wall encloses an accommodating space, the first air intake housing is annular and is located in the accommodating space, and the outer circumferential wall of the first air intake housing is sealed to the inner circumferential wall.

[0021] In some embodiments of the present invention, the volute is further provided with a first exhaust duct, which extends along the circumference of the first volute chamber, one end of the first exhaust duct is communicated with the first volute chamber, and the other end of the first exhaust duct forms a first exhaust port.

[0022] In some embodiments of the present invention, the volute assembly further includes a second air inlet housing, which is mounted on an end of the volute away from the first air inlet housing along the axial direction;

[0023] The second air inlet housing defines the second air inlet passage and the second air collecting chamber, and the volute and the second air inlet housing together define the second pressurized chamber;

[0024] The second air inlet passage and the second air collecting chamber both extend along the axial direction, and two ends of the second air collecting chamber along the axial direction are communicated with the second air inlet passage and the second pressurized chamber respectively.

[0025] In some embodiments of the present invention, the volute includes a sealing partition, which is located between the first pressurized chamber and the second pressurized chamber along the axial direction and separates the first pressurized chamber from the second pressurized chamber;

[0026] The sealing partition is provided with a first sealing structure at one end along the axial direction, and a second sealing structure at the other end along the axial direction. The first sealing structure is used to cooperate with the back rotation seal of the first impeller, and the second sealing structure is used to cooperate with the back rotation seal of the second impeller.

[0027] In some embodiments of the present invention, an assembly port is provided at one end of the first air collecting chamber along the axial direction away from the connecting port; the volute assembly also includes an air inlet guide cover, which is installed on the inner circumferential surface of the assembly port and closes the assembly port, and the side of the air inlet guide cover facing the first air collecting chamber is configured as a guide surface, at least a portion of the guide surface is inclined relative to the axial direction, and the outer diameter of the guide surface gradually decreases from the assembly port to the connecting port.

[0028] In some embodiments of the present invention, along the axial direction, the end of the air intake guide cover facing away from the first air collecting chamber is provided with a bearing mounting groove, and the bearing mounting groove is used to install a protective bearing; along the radial direction, at least part of the bearing mounting groove overlaps with the first air collecting chamber.

[0029] The second aspect of the present invention further provides a compressor, comprising: the volute assembly according to the first aspect,

[0030] The volute assembly is provided with a shaft mounting hole extending along the axial direction, and the shaft mounting hole is communicated with the first compression chamber and the second compression chamber respectively;

[0031] a first impeller disposed in the first pressurizing chamber;

[0032] a second impeller disposed in the second pressurizing chamber;

[0033] The rotor shaft is rotatably inserted into the shaft mounting hole, and part of the rotor shaft is sequentially inserted into the first compression chamber and the second compression chamber, and is connected to the first impeller and the second impeller respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference numerals are used throughout the accompanying drawings to denote the same components.

[0035] Figure 1 Schematic diagram of the structure of a volute assembly according to one embodiment of the present invention;

[0036] Figure 2 Schematic diagram of the cross-sectional structure of a volute assembly along the radial direction according to one embodiment of the present invention;

[0037] Figure 3 Schematic diagram of the cross-sectional structure of a volute assembly along the axial direction according to one embodiment of the present invention;

[0038] Figure 4 for Figure 3 A partial enlarged schematic diagram of part A;

[0039] Figure 5 Schematic diagram of the cross-sectional structure of a volute assembly along the axial direction according to another embodiment of the present invention;

[0040] Figure 6 for Figure 5 A partial enlarged schematic diagram of part B;

[0041] Figure 7 Schematic diagram of the cross-sectional structure of a compressor according to one embodiment of the present invention.

[0042] The reference numerals in the accompanying drawings represent the following:

[0043] 24. Volute assembly;

[0044] 2401, first compression chamber; 2402, second compression chamber; 24011, first air inlet; 24019, first air inlet port; 24021, first plenum chamber; 24028, assembly port; 24031, first pressurized chamber; 24012, second air inlet; 24022, second plenum chamber; 24032, second pressurized chamber; 24023, communication port; 24024, first axis; 24013, second axis.

[0045] 241, volute; 2411, main body; 2412, first volute; 24121, first volute chamber; 2414, first exhaust passage; 24141, first exhaust port; 2415, second volute; 24151, second volute chamber; 2416, second exhaust passage; 24161, second exhaust port;

[0046] 242, first air intake housing;

[0047] 243, second air intake housing;

[0048] 244, diverter rib; 2441, first segment; 24411, diverter portion; 2442, second segment;

[0049] 245, guide rib; 2451, air gap;

[0050] 246, guide surface; 24601, head end; 24602, tail end; 2461, first guide surface; 2462, second guide surface;

[0051] 247, air intake guide cover; 2471, guide surface; 2472, through hole; 2473, bearing mounting groove;

[0052] 1. Compressor;

[0053] 30. Motor; 121. Casing; 122. Second volute; 210. Third impeller; 213. Rotor shaft; 226. First impeller; 227. Second impeller; 228. First sealing structure; 229. Second sealing structure; 2160. Protective bearing; 2200. Axial magnetic bearing; 2212. Sealing partition; 2220. First radial magnetic bearing; 2230. Second radial magnetic bearing; 2281. First annular protrusion; 2282. First protrusion structure; 2283. Second protrusion structure; 2284. Third protrusion structure; 2285. Fourth protrusion structure; 22801. First sealing gap; 22802. Second sealing gap. DETAILED DESCRIPTION

[0054] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0055] It should be understood that the terms used herein are for the purpose of describing specific example embodiments only and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "comprise", "include", "contain" and "have" are inclusive and therefore specify the presence of stated features, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring them to be performed in the specific order described or illustrated, unless the order of execution is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0056] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates otherwise, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0057] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections, electrical connections, or communication between them; direct connections or indirect connections through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0058] For ease of description, spatially relative terms may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figures, such as "inside," "outside," "inside," "outside," "below," "beneath," "above," and the like. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is rotated, an element described as "below" or "beneath" another element or feature would subsequently be oriented "above" or "above" the other element or feature. Thus, the example term "below" can encompass both above and below orientations.

[0059] According to an embodiment of the present invention, a volute assembly 24 is provided. Figure 1 、 Figure 2 and Figure 3 As shown, the volute assembly 24 has a radial direction X and an axial direction Y. Specifically, the axial direction of the volute assembly 24 is parallel to the rotation axis of the impeller disposed inside the volute assembly 24, and the radial direction of the volute assembly 24 is parallel to the radial direction of the impeller disposed inside the volute assembly 24. The volute assembly 24 has a first compression chamber 2401 and a second compression chamber 2402 arranged in sequence along the axial direction.

[0060] The first and second pressurized chambers 24031 and 24032 are the core functional areas of the compression chamber. The interior of the first pressurized chamber 24031 is used to accommodate the first impeller, and the interior of the second pressurized chamber 24032 is used to accommodate the second impeller. The shapes of the first and second pressurized chambers 24031 and 24032 match the first and second impellers, respectively. Both the first and second pressurized chambers 24031 and 24032 are annular cavities. When the impellers rotate, centrifugal force acts on the gas entering the first and second pressurized chambers 24031 and 24032, thereby increasing the pressure. The first plenum 24021 is located at the inlet end of the first pressurized chamber 24031. The outlet end of the first plenum 24021 is coaxially connected to the inlet end of the first pressurized chamber 24031, ensuring that the rectified airflow enters the first pressurized chamber 24031 axially, matching the direction of work performed by the first impeller. The main function of the first air collecting chamber 24021 is to initially collect and rectify the gas introduced by the first air inlet 24011, so that the air flow evenly enters the first pressurized chamber 24031 and interacts with the first impeller. The first air inlet 24011 is located at the air inlet end of the first air collecting chamber 24021, and the outlet end of the first air inlet 24011 is connected to the inlet end of the first air collecting chamber 24021, for introducing the gas into the first air collecting chamber 24021, and at least one of the first air inlet 24011 and the second air inlet 24012 extends along a first direction, wherein the first direction is parallel to the radial direction, or the first direction forms an angle of less than 90 degrees with the radial direction, so that the first air inlet 24011 or the second air inlet 24012 can reduce the occupation of the axial space, shorten the axial spacing between the adjacent first compression chamber and the second compression chamber, and significantly reduce the axial size of the overall volute assembly 24. Shortening the axial dimension of volute assembly 24 directly creates conditions for shortening the axial length of rotor shaft 213. This shortened length enhances the rigidity of rotor shaft 213, increases the first-order bending modal frequency, reduces the risk of resonance, and significantly improves the operational stability of the high-speed magnetic levitation rotor.

[0061] In some embodiments, please combine Figure 1 、 Figure 2 and Figure 3 As shown, the volute assembly 24 includes a volute 241 and a first air intake shell 242. A first air intake duct 24011 is formed on the volute 241. A first air collecting chamber 24021 is formed on the first air intake shell 242. The volute 241 and the first air intake shell 242 jointly define a first pressurized chamber 24031.

[0062] Specifically, the volute 241 is the primary structural support component of the volute assembly 24. A radially extending first air inlet duct 24011 is machined into the interior of the volute 241. The air inlet end of the first air inlet duct 24011 is connected to an external air source, and the air outlet end of the first air inlet duct 24011 points radially outward from the first plenum chamber 24021. A first plenum chamber 24021 is formed within the first air inlet housing 242. The first plenum chamber 24021 is an annular cavity, and the inner circumferential wall of the first plenum chamber 24021 is provided with an opening that docks with the outlet of the first air inlet duct 24011. One axial end of the first plenum chamber 24021 communicates with the first pressurized chamber 24031. The overall shape of the first plenum chamber 24021 is a guide cavity with radial air inlet and axial air outlet. The material of the first air inlet housing 242 matches that of the volute 241, ensuring structural rigidity and aerodynamic performance. The first pressurized chamber 24031 is formed by the interface between the volute 241 and the first air inlet housing 242. Specifically, the first pressurized chamber 24031 is an annular cavity formed by the axially inner sidewalls of the volute 241 and the first air inlet housing 242. The central axis of the first pressurized chamber 24031 is coaxial with the magnetic levitation rotor shaft 213 and is used to accommodate the first impeller 226. The outlet of the first pressurized chamber 24031 is connected to the subsequent flow passage of the volute 241 to discharge the compressed gas.

[0063] The volute 241 and the first air inlet housing 242 are fastened together with bolts. A high-temperature-resistant gasket is installed between the mating surfaces of the volute 241 and the first air inlet housing 242 to prevent leakage of the high-pressure gas within the first pressurized chamber 24031. The axis of the mating between the volute 241 and the first air inlet housing 242 coincides with the axis of the rotor shaft 213, ensuring coaxiality between the first pressurized chamber 24031 and the impeller, thereby preventing aerodynamic imbalance during impeller rotation.

[0064] It should be noted that external gas enters the first inlet passage 24011 of the volute 241 radially, undergoes initial acceleration within the passage, and then enters the first plenum chamber 24021, where it is guided by the inner wall of the first plenum chamber 24021, converges radially inward, and gradually shifts to axial flow. The rectified airflow then enters the first pressurized chamber 24031 axially. The air in the first pressurized chamber 24031 interacts with the high-speed rotating first impeller 226. The impeller exerts centrifugal force on the gas, increasing its pressure, and the gas is ultimately discharged from the outlet of the pressurized chamber 2403 into the subsequent passage. The first inlet passage 24011 extends radially, with at least a portion of the first inlet passage 24011 radially overlapping with the first plenum chamber 24021.

[0065] In this embodiment, the volute 241 and the first air intake shell 242 are designed to be split, and can be manufactured using different processes respectively, which reduces the difficulty of processing complex inner cavities. The volute 241 and the first air intake shell 242 are connected by bolts and can be disassembled and replaced. If the first air collecting chamber 24021 or the first air intake duct 24011 is worn, there is no need to replace the volute assembly 24 as a whole.

[0066] It is understandable that in other embodiments, the extension direction of the first air inlet duct 24011 can also be set at an angle less than 90° to the radial direction (not shown in the figure), that is, the extension direction of the first air inlet duct 24011 is set to be inclined relative to the axial direction, rather than extending completely parallel to the axial direction, so that the first air inlet duct 24011 can also reduce the length of the space occupied by the axial direction.

[0067] In some embodiments, please combine Figure 1 、 Figure 2 and Figure 3 Please combine Figure 1 、 Figure 2 and Figure 3 As shown, the first plenum chamber 24021 and the first pressurized chamber 24031 have a connecting opening 24023. This connecting opening 24023 is circular or nearly circular, and its shape matches the annular cross-section of the impeller inlet. The centerline of the connecting opening 24023 is defined as a first axis 24024, which is parallel to the axial direction and coincides with the axis of the rotor shaft 213, extending axially. The diameter of the connecting opening 24023 is larger than the inlet diameter of the first impeller 226, ensuring that the airflow fully covers the impeller's working area. The edges of the connecting opening 24023 are rounded to reduce the local resistance coefficient of the airflow entering the pressurized chamber 2403. First air inlet duct 24011 is a straight or curved channel extending radially. The centerline of first air inlet duct 24011 is defined as second axis 24013. Second axis 24013 extends radially and intersects first axis 24024. Second axis 24013 is perpendicular to the first circumferential direction. Alternatively, second axis 24013 and first axis 24024 may form a non-perpendicular angle. When second axis 24013 is perpendicular to the first circumferential direction at the intersection, the intersection of second axis 24013 and first axis 24024 is located radially inward of communication opening 24023. When second axis 24013 and first axis 24024 form an angle, the intersection of second axis 24013 and first axis 24024 is located within first plenum 24021. A first air inlet 24019 is provided at the end of first air inlet duct 24011 facing away from first plenum 24021.

[0068] In this embodiment, the second axis 24013 is arranged to intersect with the first axis 24024, so that when the airflow of the first air inlet duct 24011 flows into the first air collecting chamber 24021, it is directly aligned with the center of the connecting port 24023, which is conducive to the airflow entering the interior of the first air collecting chamber 24021 evenly through the connecting port 24023, avoiding the formation of a low-speed zone on one side of the connecting port 24023, and allowing the airflow entering the first air collecting chamber 24021 through the connecting port 24023 to diffuse to the surrounding areas from the center of the connecting port 24023, forming a radially symmetrical flow pattern, and flowing evenly to the first impeller 226, thereby improving the working efficiency of the first impeller 226.

[0069] In some implementations, combine Figure 1 、 Figure 2 and Figure 3 As shown, the volute assembly 24 further includes a diverter rib 244, which includes a first segment 2441 disposed in the first air inlet duct 24011 and a second segment 2442 disposed in the first plenum chamber 24021. The first segment 2441 and the second segment 2442 are abutted against each other and both extend in the lengthwise direction of the second axis 24013. It is understood that when the first air inlet housing 242 is mounted on the volute 241, the first segment 2441 and the second segment 2442 are aligned, and the overall length of the diverter rib 244 extends in the direction that coincides with the second axis 24013. Therefore, the extension line of the lengthwise direction of the diverter rib 244 intersects the first axis 24024.

[0070] The end of the first segment 2441 facing away from the second segment 2442 is provided with a diverter portion 24411. The diverter rib 24411 is streamlined overall, with the thickness of the diverter portion 24411 gradually increasing along the direction of airflow in the first air inlet duct 24011. The function of the diverter portion 24411 is to reduce the resistance of airflow passing through the diverter rib 244. The end of the second segment 2442 facing away from the first segment 2441 extends directly to the circumferential edge of the communication port 24023.

[0071] In this embodiment, the diverter rib 244 radially divides the interior space of the first inlet duct 24011 and the first plenum chamber 24021 into two sub-flow channels, causing the airflow to be diverted into two parallel and symmetrical streams upon entry. This restricts lateral diffusion of the airflow, forces turbulent airflow to flow along a predetermined path, reduces the generation of vortices, and avoids energy loss caused by vortices, effectively preventing a loss of aerodynamic efficiency. Specifically, the extension line of the diverter rib 244 intersects the first axis 24024, and the guide direction of the diverter rib 244 directly points to the center of the connecting port 24023, which is equivalent to providing a smooth transition path for the airflow. After the airflow is diverted by the diverter rib 244, the extension direction of the circumferential inner wall of the first plenum chamber 24021 naturally adjusts the flow direction, reducing the vertical impact angle on the wall surface of the first plenum chamber 24021 opposite the first inlet duct 24011, reducing kinetic energy loss during the diversion process, and allowing more airflow energy to be effectively converted into pressure energy that drives the first impeller 226 to rotate.

[0072] Figure 2 The direction of gas flow in the first air inlet and the first air collecting chamber is the direction indicated by the dotted arrow. Figure 2 As shown, the diverter ribs 244 ensure that the flow rate and speed of each sub-channel are consistent by evenly dividing the airflow, so that the airflow can evenly cover the inlet cross-section of the first impeller 226 when passing through the connecting port 24023. The impeller blades are subjected to balanced force, ensuring the impeller's efficient conversion of airflow energy and indirectly avoiding the loss of aerodynamic efficiency.

[0073] In other embodiments, the diverter rib 244 may be disposed only in the first air collecting chamber 24021 or only in the first air inlet duct 24011 , and may also have the above diverter effect, which will not be elaborated herein.

[0074] In some embodiments, please combine Figure 1 、 Figure 2 and Figure 3 As shown, the volute assembly 24 further includes at least one guide rib 245, which is disposed within the first plenum chamber 24021. The guide rib 245 is located entirely in the middle front portion of the first plenum chamber 24021 along the airflow direction. The middle front portion of the first plenum chamber 24021 along the airflow direction is the area of ​​the first plenum chamber 24021 between the first axis 24024 and the first air inlet duct 24011, extending along the second axis 24013. The purpose of placing the guide rib 245 as a whole in the middle front part of the first air collecting chamber 24021 along the air flow direction is to use the guide rib 245 to guide and divert the air flow after the diverter rib 244 diverts the gas, forming a relay-type guide with diverter rib 244 pre-guidance + guide rib 245 fine-tuning, that is, the diverter rib 244 divides the air flow in the first air inlet duct 24011 and the first air inlet cavity, and the guide rib 245 completes the turning in the air collecting chamber 2402.

[0075] The guide rib 245 is positioned outside the communication opening 24023 around the first axis 24024. The guide rib 245 is inclined relative to the second axis 24013. The first end of the guide rib 245 extends to the circumferential edge of the communication opening 24023, and the second end of the guide rib 245 is positioned closer to the first air inlet 24019 than the first end. That is, along the direction of the second axis, the distance from the second end of the guide rib 245 to the first air inlet 24019 is shorter than the distance from the first end to the first air inlet 24019.

[0076] When the airflow flows along the surface of the guide rib 245, the curvature of the guide rib 245 gradually changes, forcing the flow direction of the airflow to gradually transition from radial to axial, so that the angle between the direction angle of the airflow and the first axis 24024 is uniformly reduced and close to the axial direction, and finally the radial flow of the airflow is transformed into axial flow.

[0077] In this embodiment, when there are multiple guide ribs 245, the multiple guide ribs 245 are distributed in a ring around the first axis 24024, and the symmetrical center lines of each rib pass through the first axis 24024, forming a radial structure with the first axis 24024 as the center, ensuring uniform circumferential guidance of the airflow.

[0078] The guide rib 245 is integrally formed with the inner wall of the first air inlet housing 242 or is welded thereto.

[0079] In some embodiments, please combine Figure 1 、 Figure 2 and Figure 3 As shown, the guide ribs 245 are arranged in pairs, with each pair of guide ribs 245 symmetrically arranged about the second axis 24013. This ensures a symmetrical distribution of airflow guidance around the communication opening 24023 and within the first plenum 24021. When air flows from the first air inlet 24011 through the communication opening 24023 and into the first plenum 24021, the guide ribs 245 on both sides exert symmetrical guiding forces on the airflow, avoiding airflow deflection or localized flow velocity differences caused by a single guide rib 245. This ensures uniform circumferential diffusion of airflow within the first plenum 24021 and reduces localized eddies or turbulence caused by uneven airflow distribution.

[0080] In this embodiment, a pair of guide ribs 245 are provided in the first plenum chamber 24021, with the two guide ribs 245 in the pair being located on either side of the second axis 24013. In other embodiments, multiple pairs of guide ribs 245 may be provided, with the multiple pairs of guide ribs 245 being sequentially spaced along the circumference of the communication opening 24023.

[0081] Furthermore, the guide rib 245 has a first guide surface facing the first air inlet and a second guide surface opposite the first guide surface. The first guide surface is a concave curved surface, and the second guide surface is a convex curved surface, so that the guide rib 245 as a whole has an arc-shaped plate structure. Specifically, the arc-shaped plate structure can reduce the frictional resistance between the airflow and the surface of the guide rib 245 compared to a straight or sharp-angled structure. The first guide surface is a concave curved surface, so that when the airflow flows through the guide rib 245, it can smoothly transition along the first guide surface of the guide rib 245. Under the guidance of the first guide surface of the guide rib 245 (close to the side of the connecting port 24023), the airflow gradually converges radially inward, reducing the generation of local turbulence and vortexes, thereby reducing aerodynamic drag losses.

[0082] Furthermore, the thickness of the guide rib 245 increases and then decreases from the radially outer side to the radially inner side of the first plenum chamber 24021, i.e., the cross-section of the guide rib 245 has a typical airfoil-shaped structure. With this arrangement, after airflow from the first inlet duct 24011 flows into the first plenum chamber 24021, it first strikes the leading edge of the guide rib 245 (i.e., the end of the guide rib 245 radially facing away from the communication opening 24023). The leading edge is relatively thin, resulting in a smaller airflow impact angle and lower energy loss. The thickness of the middle area of ​​the guide rib 245 is increased, which can prevent the airflow from forming vortices on the surface of the guide rib 245. The trailing edge of the guide rib 245 (that is, the end of the guide rib 245 radially toward the connecting port 24023) gradually becomes thinner, so that the airflow can smoothly leave the surface of the guide rib 245, reducing the pressure difference resistance caused by the tail vortex, so that the guide rib 245 has a guiding function and also reduces the resistance of the airflow when flowing through the guide rib 245.

[0083] It should be noted that in this embodiment, a wind gap 2451 is provided between the end of the guide rib 245 radially away from the communication opening 24023 and the circumferential inner wall of the first plenum chamber 24021. This allows the airflow diverted by the diverter rib 244 to, when flowing through the guide rib 245, have a portion of the airflow redirected by the diverter rib 245 toward the communication opening 24023, while the remaining portion of the airflow flows through the wind gap 2451 toward the middle and rear portion of the first plenum chamber 24021 along the airflow direction. In other words, in addition to its guiding function, the guide rib 245 also has a diverting function, causing the airflow diverted by the diverter rib 244 to be diverted again when passing through the guide rib 245. This allows the guide rib 245 to simultaneously perform multiple functions, thereby improving the compactness of the volute assembly 24 structural design.

[0084] The middle and rear part of the first air collecting chamber 24021 along the airflow direction, i.e., along the extension direction of the second axis 24013 , is located in the area of ​​the first air collecting chamber 24021 on the side of the first axis 24024 away from the first air inlet duct 24011 .

[0085] Furthermore, please combine Figure 2 and Figure 3 As shown, the inner wall of first plenum chamber 24021 is further provided with a guide surface 246, or the guide surface 246 is substantially formed by a portion of the circumferential inner wall of first plenum chamber 24021. Along the extension direction of second axis 24013, guide surface 246 is located on the side of first axis 24024 facing away from first air inlet 24019. After being diverted by guide ribs 245 and flowing into the center and rear portion of first plenum chamber 24021 through air gap 2451, the airflow is further redirected by guide surface 246 and flows toward communication opening 24023.

[0086] Specifically, the radial spacing between the guide surface 246 and the circumferential edge of the connecting opening 24023 gradually decreases along the direction from the first air inlet 24019 to the connecting opening 24023. The radial spacing refers to the distance between the guide surface 246 and the circumferential edge of the connecting opening 24023 in a direction perpendicular to the first axis 24024. The direction from the first air inlet 24019 to the connecting opening 24023 is the mainstream convergence direction of the airflow within the first plenum 24021. Therefore, the radial distance between the guide surface 246 and the edge of the connecting opening 24023 gradually decreases from the side closest to the first air inlet 24019 to the side closest to the connecting opening 24023, forming a tapered channel that guides the airflow from wide to narrow and converges toward the connecting opening 24023.

[0087] Among them, the guide surface 246 is an arc-shaped wall surface. Along the circumference of the first air collecting chamber 24021, the guide surface 246 has a head end 24601 and a tail end 24602. The head end 24601 is closer to the first air inlet 24011 than the tail end 24602. The head end 24601 is smoothly connected to the inner wall surface of the middle front part of the first air collecting cavity, and the head end 24601 is smoothly connected to the inner wall surface of the middle front part, so that when the airflow enters the middle and rear part of the first air collecting chamber 24021 from the middle front part of the first air collecting chamber 24021, it can flow along a continuous curved surface, avoiding airflow impact caused by structural mutation, ensuring the continuity of the airflow from the early path to the middle and rear part, and reducing local energy loss.

[0088] The tail end 24602 extends to the circumferential edge of the communication opening 24023, so that the terminal position of the guide surface 246 is completely connected with the inlet boundary of the communication opening 24023. When the airflow flows along the guide surface 246 to the tail end 24602, it can directly enter the communication opening 24023, avoiding the airflow diffusion caused by the distance between the guide surface 246 and the communication opening 24023. The tail end 24602 intersects the second axis 24013, that is, the arc-shaped extension of the guide surface 246 ultimately points to the intersection of the second axis 24013 and the first axis 24024, which is also the center of the communication opening 24023. The direction of the airflow guided by the guide surface 246 is gathered toward the center of the connecting port 24023, so that the airflow can enter the connecting port 24023 in a radially symmetrical and axially consistent direction, thereby improving the uniformity of the flow rate of the airflow in the connecting port 24023, and allowing the airflow flowing into the first pressurized chamber 24031 through the connecting port 24023 to be delivered to the first impeller 226 at a uniform flow rate, thereby improving the working stability of the first impeller 226 and reducing the vibration and noise of the first impeller 226.

[0089] In some embodiments, as Figure 2 As shown, the guide surface 246 includes a first guide surface 2461 and a second guide surface 2462, which are symmetrically arranged about the second axis 24013. In this embodiment, the first guide surface 2461 and the second guide surface 2462 respectively cooperate with the two paired guide ribs 245. The airflow flowing into the middle and rear portion through the air gap 2451 of the paired guide ribs 245 is naturally divided into two left and right streams, with the first guide surface 2461 guiding the left airflow and the second guide surface 2462 guiding the right airflow. The arc curvature and the front and rear ends 24601 and 24602 of the two guide surfaces are completely symmetrical, ensuring that the flow path lengths, turning angles, and pressure losses of the left and right airflows in the middle and rear portion are completely consistent. This ensures that the energy distribution of the left and right airflows is more balanced when they finally converge at the connecting port 24023, reducing local vortices or pressure fluctuations caused by flow field asymmetry.

[0090] In some embodiments, as Figure 2 and Figure 3As shown, the volute 241 includes a main body 2411 and a first volute 2412. The main body 2411 is the main support structure of the volute 2411 and integrates the first air inlet 24011. The first volute 2412 is connected to the main body 2411 along one end of the axial direction. The first volute 2412 has an annular structure. The interior of the first volute 2412 defines a first volute chamber 24121. The first volute chamber 24121 is an annular flow passage surrounding the first pressurized chamber 24031 and communicating with the exhaust end of the first pressurized chamber 24031. The first volute chamber 24121 is used to convert the high-speed airflow discharged from the first pressurized chamber 24031 into pressure energy. The first volute 2412 has an inner circumferential wall arranged around the first axis 24024, which encloses a storage space. The first air inlet housing 242 is annular and is located within the storage space.

[0091] As can be understood, the first air intake housing 242 is embedded within the accommodation space of the first volute portion, forming an axially nested structure. Compared to a conventional structure in which the air intake housing and volute 241 are axially connected in series, this effectively reduces the axial length. This makes the volute assembly 24 more compact in the axial direction, thereby directly reducing the axial span of the rotor shaft 213, helping to increase the first-order bending modal frequency and enhance rotor stability.

[0092] Furthermore, if Figure 3 and Figure 4 As shown, the outer circumferential wall of the first air intake housing 242 is sealed to the inner circumferential wall. The radial fit between the first air intake housing 242 and the first volute portion forms a surface-contact seal with a large contact area, dispersing the gas pressure on the sealing surface and preventing seal failure caused by excessive local pressure. Specifically, the first air intake housing 242 and the inner circumferential wall can be sealed with an O-ring. The O-ring has excellent elasticity and will deform elastically under the action of axial preload, filling minor imperfections on the sealing surface. Its temperature resistance range can adapt to the temperature fluctuations during the operation of the compressor 1, ensuring sealing stability under high pressure.

[0093] In some embodiments, as Figure 1 、 Figure 2 and Figure 3As shown, the volute 241 is further provided with a first exhaust duct 2414, which extends circumferentially around the first volute chamber 24121. One end of the first exhaust duct 2414 communicates with the first volute chamber 24121, and the other end of the first exhaust duct 2414 forms a first exhaust port 24141. Specifically, the first volute chamber 24121 is an annular space surrounding the first pressurized chamber 24031. The pressurized gas therein flows primarily in the circumferential direction. The circumferential extension of the first exhaust duct 2414 aligns with the flow direction of the gas within the first volute chamber 24121, allowing the gas to enter the first exhaust duct 2414 from the first volute chamber 24121 without a significant change in flow direction. This reduces eddies, shocks, and flow separation caused by sudden changes in flow direction, reduces local energy losses, and improves the continuity and smoothness of gas flow.

[0094] In some embodiments, as Figure 2 and Figure 3 As shown, the volute assembly 24 further includes a second air inlet housing 243 , which is mounted on one end of the volute 241 axially away from the first air inlet housing 242 .

[0095] The second air inlet housing 243 is formed with a second air inlet duct 24012 and a second plenum 24022. The volute 241 and the second air inlet housing 243 jointly define a second pressurized chamber 24032, which is used to accommodate the second impeller 227. Both the second air inlet duct 24012 and the second plenum 24022 extend axially, aligned with the direction of air inlet, reducing airflow steering losses. The rectifying effect of the second plenum 24022 makes the airflow entering the pressurized chamber 2403 more uniform, preventing the reduction in impeller efficiency caused by airflow turbulence. The second plenum 24022's two axial ends communicate with the second air inlet duct 24012 and the second pressurized chamber 24032, respectively.

[0096] In this embodiment, the external gas first enters the second air inlet duct 24012 axially. Since the second air inlet duct 24012 extends axially, the gas can flow in smoothly, reducing the initial flow resistance. The gas enters the axially extended second air collecting chamber 24022 through the second air inlet duct 24012, and axially enters the second pressurization chamber 24032 from the second air collecting chamber 24022, interacting with the rotating second impeller 227, so that the gas obtains kinetic energy and pressure energy, completing the pressurization process.

[0097] In some embodiments, as Figure 3 and Figure 5As shown, the volute 241 also includes a second volute portion 2415, which is connected to the end of the main body 2411 axially away from the first volute portion. The second volute portion 2415 has an annular structure and defines a second volute chamber 24151 within the second volute portion 2415. The second volute chamber 24151 is an annular flow passage surrounding the second pressurized chamber 24032 and communicating with the exhaust end of the second pressurized chamber 24032. The second volute chamber 24151 is used to convert the high-speed airflow discharged from the second pressurized chamber 24032 into pressure energy. The second air inlet housing 243 is mounted on the end of the second volute portion 2415 axially away from the first air inlet housing 242.

[0098] The volute 241 is further provided with a second exhaust duct 2416, which extends circumferentially around the second volute chamber 24151. One end of the second exhaust duct 2416 communicates with the second volute chamber 24151, and the other end of the second exhaust duct 2416 forms a second exhaust port 24161. Specifically, the second volute chamber 24151 is an annular space surrounding the second pressurized chamber 24032. The pressurized gas within the second volute chamber 24151 flows primarily in the circumferential direction. The circumferential extension of the second exhaust duct 2416 aligns with the flow direction of the gas within the second volute chamber 24151, allowing the gas to enter the second exhaust duct 2416 from the second volute chamber 24151 without a significant change in flow direction. This reduces eddies, shocks, and flow separation caused by sudden changes in flow direction, reduces local energy losses, and improves the continuity and smoothness of gas flow.

[0099] In some embodiments, as Figure 3 、 Figure 5 and Figure 6 As shown, the volute 241 includes a sealing partition 2212, which is axially located between the first pressurized chamber 24031 and the second pressurized chamber 24032 and separates the first pressurized chamber 24031 from the second pressurized chamber 24032. The sealing partition 2212 is an integrated structure with the main body 2411 and the first volute, providing a strong integrity, better sealing performance, and reducing the risk of gas leakage.

[0100] Among them, the two ends of the sealing partition 2212 along the axial direction are respectively opposite to the back of the first impeller 226 and the back of the second impeller 227. A first sealing structure 228 is provided at one end of the sealing partition 2212 along the axial direction, and a second sealing structure 229 is provided at the other end of the sealing partition 2212 along the axial direction. The first sealing structure 228 is used to cooperate with the back of the first impeller 226 for rotational sealing, and the second sealing structure 229 is used to cooperate with the back of the second impeller 227 for rotational sealing.

[0101] According to the volute assembly 24 proposed in the present invention, two impellers are coaxially arranged within the same volute assembly 24 and separated by a sealed partition 2212. This reduces axial space usage, facilitates shortening the length of the rotor shaft 213, and satisfies the axial length requirement of high-speed magnetic levitation rotors. This can increase the first-order bending modal frequency and enhance rotor stability. Compared to the two independent sealing structures in the prior art, the present invention only requires a sealing structure between the back of the first impeller 226 and the back of the second impeller 227 and the sealed partition 2212. This reduces the number of wheel back seals, simplifies the sealing system, and reduces the design and maintenance costs of the sealing structure. It also reduces the risk of leakage caused by an excessive number of sealing components, thereby improving compression efficiency.

[0102] In some embodiments, please combine Figure 3 、 Figure 5 and Figure 6 As shown, the first and second sealing structures are configured as a plurality of coaxially arranged first annular teeth 2281. The sealing partition is provided with at least one group of first annular teeth 2281, each group comprising a plurality of first annular teeth 2281. The plurality of first annular teeth 2281 in each group are radially spaced sequentially to form a multi-layered annular tooth gap structure. The gaps between adjacent first annular teeth 2281 form a tortuous airflow channel. When the first annular teeth 2281 are arranged on both sides of the sealing partition 2212 along the axial direction, the first annular teeth 2281 on both sides of the sealing partition 2212 are arranged opposite the back of the first impeller 226 and the back of the second impeller 227. When the first impeller 226 and the second impeller 227 rotate, the first annular teeth 2281 maintain a slight gap with the back of the first impeller 226 and the back of the second impeller 227. It is understandable that the first annular protrusion 2281 can also be set on the back of the first impeller 226 and the back of the second impeller 227, and opposite to the corresponding surface of the sealing partition 2212 to form a dynamic and static sealing gap.

[0103] The first annular protruding tooth 2281 extends obliquely toward the radial outside of the first impeller 226 relative to the first direction, that is, the top of the first annular protruding tooth 2281 is closer to the outer periphery of the impeller than the root, forming an inclination angle opening radially outward.

[0104] It should be noted that the first annular protruding tooth 2281 is an integrated structure. If it is provided on the back of the sealing partition 2212 or the first impeller 226 and the second impeller 227, it is integrally formed and fixed with the corresponding components by casting or machining.

[0105] In this embodiment, the first and second sealing structures are based on the labyrinth seal principle, forming a tortuous airflow path through multiple layers of inclined convex teeth to prevent the leakage of high-pressure side gas to the low-pressure side. Specifically, if the high-pressure gas in the second pressurized chamber leaks to the low-pressure side of the first pressurized chamber, it must pass through the gaps between the multiple first annular convex teeth 2281 in sequence. Because the first annular convex teeth 2281 are radially spaced and inclined, the leakage path is forced to bend. With each convex tooth gap, the gas experiences a pressure drop due to the throttling effect. After passing through multiple layers of first annular convex teeth 2281, the leakage rate is significantly attenuated. In addition, when the first impeller 226 and the second impeller 227 rotate, an air film forms between the back of the impeller and the small gap between the first annular convex teeth 2281. The first annular convex teeth 2281 can reduce the disturbance of the rotating airflow on the sealing gap, thereby avoiding the fluctuation of the leakage rate due to the unstable airflow in the gap.

[0106] Furthermore, in some embodiments, Figure 6 As shown, the first sealing structure 228 further includes a plurality of second protrusion structures 2283. A plurality of annular first protrusion structures 2282 are provided on the back of the first impeller 226. The first protrusion structures 2282 are coaxially disposed with the first impeller 226, and the plurality of first protrusion structures 2282 are sequentially spaced apart along the radial direction of the first impeller 226. The plurality of second protrusion structures 2283 are annular and formed at one end of the sealing partition 2212 facing the first impeller 226, and are coaxially disposed with the first impeller 226. The plurality of second protrusion structures 2283 are sequentially spaced apart along the radial direction of the first impeller 226. Among them, multiple first protrusion structures 2282 and multiple second protrusion structures 2283 are arranged alternately in sequence along the radial direction of the first impeller 226, that is, each first protrusion structure 2282 is located between two adjacent second protrusion structures 2283 in the radial direction, thereby defining a first sealing gap 22801 extending in a broken line along the radial direction of the first impeller 226 between the back of the first impeller 226 and the sealing partition 2212. The first sealing gap 22801 includes multiple first radial segments extending in the radial direction and multiple first axial segments extending in the axial direction of the first impeller, and the multiple first radial segments and the multiple first axial segments are alternately connected in sequence.

[0107] The staggered arrangement of multiple radial annular protrusions creates a complex, zigzag path within the sealed area, forcing gas to undergo multiple changes of direction and throttling resistance before escaping, significantly increasing the seal impedance and reducing the leakage rate. In this embodiment, at least one of the first protrusion 2282 and the second protrusion 2283 is provided with the aforementioned first annular protrusion 2281, facilitating the deployment of more sealing stages within a limited structural cavity and improving the overall sealing performance.

[0108] In some embodiments, as Figure 6As shown, the first sealing structure 228 further includes a plurality of fourth protrusion structures 2285. A plurality of annular third protrusion structures 2284 are provided on the back of the second impeller 227. The third protrusion structures 2284 are coaxially arranged with the second impeller 227, and the plurality of third protrusion structures 2284 are sequentially spaced along the radial direction of the second impeller 227. The plurality of fourth protrusion structures 2285 are annular and formed at one end of the sealing partition 2212 facing the second impeller 227. The plurality of fourth protrusion structures 2285 are coaxially arranged with the second impeller 227, and the plurality of fourth protrusion structures 2285 are sequentially spaced along the radial direction of the second impeller 227. Among them, multiple third protrusion structures 2284 and multiple fourth protrusion structures 2285 are staggered in sequence along the radial direction of the second impeller 227, that is, each third protrusion structure 2284 is located between two adjacent fourth protrusion structures 2285 in the radial direction, thereby defining a second sealing gap 22802 extending in a broken line along the radial direction of the second impeller 227 between the back of the second impeller 227 and the sealing partition 2212, and the second sealing gap 22802 includes multiple second radial segments extending in the radial direction and multiple second axial segments extending in the axial direction of the first impeller, and the multiple second radial segments and the multiple second axial segments are alternately connected in sequence.

[0109] The staggered arrangement of multiple radial annular raised structures creates a complex return path within the sealed area, forcing gas to undergo multiple changes of direction and throttling resistance before escaping, significantly increasing the seal impedance and reducing the leakage rate. In this embodiment, at least one of the third raised structure 2284 and the fourth raised structure 2285 is equipped with the aforementioned first annular protrusion 2281, facilitating the deployment of more sealing stages within a limited structural cavity and improving the overall sealing level.

[0110] In some embodiments, an assembly port 24028 is provided at one end of the first air collecting chamber 24021 axially away from the connecting port 24023. The assembly port 24028 is a circular opening. The inner circumference of the assembly port 24028 is provided with a positioning stop for installing and positioning the air intake guide cover 247. The diameter of the assembly port 24028 is larger than the connecting port 24023.

[0111] The volute assembly 24 also includes an air inlet guide cover 247, which is mounted on the inner circumference of the assembly opening 24028 and seals the assembly opening 24028. The air inlet guide cover 247 is disc-shaped or conical, with its outer circumference connected to the inner circumference of the assembly opening 24028 by an interference fit or bolt fastening. A rubber sealing ring is provided on the contact surface to seal the assembly opening 24028. The air inlet guide cover 247 also includes a through hole 2472 that mates with the rotor shaft 213. The axis of the through hole 2472 is collinear with the first axis 24024 of the communication opening 24023. The inner wall of the through hole 2472 is provided with a labyrinth seal structure, which provides a rotationally sealed engagement with the outer circumference of the rotor shaft 213.

[0112] One side of the air intake guide cover 247 facing the first air collecting chamber 24021 is processed into a guide surface 2471. At least part of the guide surface 2471 is tilted relative to the axial direction, and the outer diameter of the guide surface 2471 gradually decreases from the assembly port 24028 to the connecting port 24023, that is, the guide surface 2471 as a whole has a conical tapered structure.

[0113] When the airflow entering the first plenum chamber 24021 and being directly guided by the guide ribs 245 and the airflow guided by the guide surface 246 flows toward the connecting port 24023, part of the airflow may diffuse toward the side of the assembly port 24028 of the plenum chamber 2402. The design of the guide surface 2471, in which the outer diameter gradually decreases from the assembly port 24028 to the connecting port 24023, will produce this diffused airflow. Through the constraint of the inclined curved surface, the airflow is forced to contract radially inward while flowing axially toward the connecting port 24023, forming a compound motion of axial propulsion and radial convergence, thus preventing the airflow from forming a stagnant vortex at the rear end. In addition, the airflow guided by the guide surface 2471 increases the axial flow component, and the radial velocity distribution of the airflow is more uniform, so that after entering the first pressurized chamber 24031, it is completely matched with the blade attack angle of the first impeller 226, reducing the blade impact caused by airflow deflection and extending the service life of the first impeller 226.

[0114] In some embodiments, as Figure 3 and Figure 4 As shown, along the axial direction, a bearing mounting groove 2473 is provided at one end of the air intake guide cover 247 away from the first air collecting chamber 24021. The bearing mounting groove 2473 is used to install and protect the bearing 2160. Along the radial direction, at least part of the bearing mounting groove 2473 overlaps with the first air collecting chamber 24021.

[0115] It should be noted that, in the existing solution, the bearing mounting position and the first air collecting chamber 24021 need to be arranged in sequence along the axial direction, and the length of the axial space occupied by the bearing mounting position and the first air collecting chamber 24021 is at least the sum of their thicknesses. However, this embodiment reduces the occupied length of the axial space through radial overlap, thereby shortening the axial length of the protective bearing 2160 and the first air collecting chamber 24021, directly reducing the span of the rotor shaft 213, increasing the first-order bending modal frequency, and reducing the risk of resonance.

[0116] In addition, the air inlet guide cover 247 simultaneously performs three functions: air flow guidance, sealing the assembly port 24028, and bearing installation. Compared with the split design of the traditional guide cover with an independent bearing seat, it effectively reduces the number of parts, reduces assembly errors, and makes the overall structure of the volute assembly 24 more compact.

[0117] According to the embodiments of the present application, Figure 7As shown, a compressor 1 is also provided, comprising a casing 121, a rotor shaft 213, a first impeller 226, a second impeller 227, and at least one volute assembly 24. The casing 121 is connected to the first air intake housing in the volute assembly. The rotor shaft 213 is rotatably disposed in the casing 121 and passes through a through hole in the air intake guide cover. Part of the rotor shaft 213 is located in the first and second pressurized chambers and is connected to the first and second impellers 226, 227, respectively.

[0118] In some embodiments, as Figure 7 As shown, the compressor 1 includes a volute assembly 24, a second volute 122, a third impeller 210, a motor 30, a first radial magnetic bearing 2220, a second radial magnetic bearing 2230, an axial magnetic bearing 2200, a protective bearing 2160, etc. The volute assembly and the second volute 122 are respectively mounted on both ends of the casing 121 in the axial direction. The first radial magnetic bearing 2220, the second radial magnetic bearing 2230, the axial magnetic bearing 2200, and the protective bearing 2160 are mounted inside the casing 121. The rotor shaft 213 is sequentially disposed through the first radial magnetic bearing 2220, the second radial magnetic bearing 2230, the axial magnetic bearing 2200, and the protective bearing 2160. One end of the rotor shaft 213 is located in the first and second pressurized chambers and is connected to the first impeller 226 and the second impeller 227, respectively. The other end of the rotor shaft 213 is located in the second volute 122 and is connected to the third impeller 210.

[0119] The interior of the second volute 122 has a third pressurized chamber, and the third impeller 210 in the third pressurized chamber compresses the gas inside again. The first pressurized chamber, the second pressurized chamber and the third pressurized chamber are connected in series through external pipelines, so that the compressor 1 can achieve three-stage compression and output high-pressure gas. Figure 2 and Figure 7 As shown, the third pressurized chamber can be the first stage compression, the second pressurized chamber can be the second stage compression, and the first pressurized chamber can be the third stage compression. Figure 5 As shown, the second pressurized chamber can be the first stage compression, the first pressurized chamber can be the second stage compression, and the third pressurized chamber can be the third stage compression.

[0120] Among them, the first radial magnetic bearing 2220 and the second radial magnetic bearing 2230 are magnetic levitation bearings for driving the rotor shaft 213 to be suspended in the radial direction, and the axial magnetic bearing 2200 is an axial magnetic levitation bearing for driving the rotor shaft 213 to be suspended in the axial direction.

[0121] The compressor 1 proposed in the present invention is a centrifugal air compressor, which can be a two-stage centrifugal air compressor, a multi-stage centrifugal air compressor, or a magnetic levitation centrifugal air compressor. The compressor 1 can also be a centrifugal machine used in a refrigeration system, that is, a centrifugal compressor.

[0122] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A volute assembly, characterized in that: The volute assembly has a radial direction and an axial direction, and defines a first compression chamber and a second compression chamber arranged in sequence along the axial direction, the first compression chamber includes a first air inlet passage, a first air collecting chamber, and a first pressurizing chamber connected in sequence, the first pressurizing chamber is used to accommodate a first impeller, and the second compression chamber includes a second air inlet passage, a second air collecting chamber, and a second pressurizing chamber connected in sequence, the second pressurizing chamber is used to accommodate a second impeller; At least one of the first air inlet duct and the second air inlet duct extends along a first direction, and the first direction is parallel to the radial direction or forms an angle less than 90° with the radial direction.

2. The volute assembly according to claim 1, characterized in that The volute assembly includes a connected volute and a first air inlet housing; The volute defines the first air inlet passage, the first air inlet housing defines the first air collecting chamber, and the volute and the first air inlet housing together define the first pressurized chamber; One end of the first air collecting chamber along the axial direction is communicated with the first pressurized chamber, the first air inlet duct passes through the inner circumferential wall of the first air collecting chamber, the first air inlet duct extends along the radial direction, and at least part of the first air inlet duct overlaps with the first air collecting chamber along the radial direction.

3. The volute assembly according to claim 2, characterized in that The first air collecting chamber and the first pressurized chamber have a connecting port, the first air inlet duct is provided with a first air inlet at one end radially away from the first air collecting chamber, the connecting port has a first axis, the first air inlet duct has a second axis, the first axis is parallel to the axial direction, and the first axis intersects with the second axis.

4. The volute assembly according to claim 3, characterized in that The volute assembly further includes a diverter rib extending along the second axis, wherein the diverter rib is located in the compression chamber and is provided between the communication port and the first air inlet.

5. The volute assembly according to claim 3, characterized in that The volute assembly also includes at least one guide rib, which is arranged in the first air collecting chamber and is located outside the connecting port around the first axis. The guide rib is inclined relative to the second axis, and the first end of the guide rib extends to the circumferential edge of the connecting port. Along the direction of the second axis, the distance from the second end of the guide rib to the first air inlet is smaller than the distance from the first end to the first air inlet.

6. The volute assembly according to claim 5, characterized in that The guide ribs are arranged in pairs, and each pair of guide ribs is symmetrically arranged with the second axis as the symmetry axis.

7. The volute assembly according to claim 5, characterized in that The guide rib has a first guide surface facing the first air inlet and a second guide surface opposite to the first guide surface, the first guide surface is a concave curved surface, and the second guide surface is a convex curved surface; And / or, in a direction from the radial outer side to the radial inner side of the first air collecting chamber, the thickness of the guide rib first increases and then decreases.

8. The volute assembly according to claim 3, wherein: The circumferential inner wall of the first air collecting chamber is further provided with a guide surface, and along the extension direction of the second axis, the guide surface is located on a side of the first axis away from the first air inlet; Along the direction from the first air inlet to the communicating port, the radial distance between the guide surface and the circumferential edge of the communicating port gradually decreases.

9. The volute assembly according to claim 8, characterized in that The guide surface includes a first guide surface and a second guide surface, and the first guide surface and the second guide surface are symmetrically arranged with the second axis as a symmetry axis.

10. The volute assembly according to claim 8, wherein: Along the circumference of the first air collecting chamber, the guide surface has a head end and a tail end, the head end is closer to the first air inlet duct than the tail end, the head end is smoothly connected to the circumferential inner wall of the first air collecting chamber, and the tail end extends to the circumferential edge of the connecting port, and the tail end intersects with the second axis.

11. The volute assembly according to claim 3, wherein: The volute includes a main body and a first volute portion connected to one end of the main body along the axial direction, the first volute portion defines a first volute chamber, the first volute chamber is circumferentially arranged outside the first pressurizing chamber, and the first volute chamber is communicated with the exhaust end of the first pressurizing chamber; The first volute portion has an inner circumferential wall arranged around the first axis, the inner circumferential wall encloses an accommodating space, the first air intake housing is annular and is located in the accommodating space, and the outer circumferential wall of the first air intake housing is sealed to the inner circumferential wall.

12. The volute assembly according to claim 11, wherein: The volute is further provided with a first exhaust passage, which extends along the circumference of the first volute chamber. One end of the first exhaust passage is communicated with the first volute chamber, and the other end of the first exhaust passage forms a first exhaust port.

13. The volute assembly according to any one of claims 2 to 12, characterized in that: The volute assembly further includes a second air inlet housing, which is mounted on one end of the volute away from the first air inlet housing along the axial direction; The second air inlet housing defines the second air inlet passage and the second air collecting chamber, and the volute and the second air inlet housing together define the second pressurized chamber; The second air inlet passage and the second air collecting chamber both extend along the axial direction, and two ends of the second air collecting chamber along the axial direction are communicated with the second air inlet passage and the second pressurized chamber respectively.

14. The volute assembly according to claim 13, wherein: The volute includes a sealing partition, which is located between the first pressurized chamber and the second pressurized chamber in the axial direction and separates the first pressurized chamber from the second pressurized chamber; The sealing partition is provided with a first sealing structure at one end along the axial direction, and a second sealing structure at the other end along the axial direction. The first sealing structure is used to cooperate with the back rotation seal of the first impeller, and the second sealing structure is used to cooperate with the back rotation seal of the second impeller.

15. The volute assembly according to claim 3, wherein: An assembly opening is provided at one end of the first plenum chamber away from the communication opening along the axial direction; The volute assembly also includes an air intake guide cover, which is installed on the inner circumferential surface of the assembly port and closes the assembly port. The side of the air intake guide cover facing the first air collecting chamber is configured as a guide surface, at least part of the guide surface is inclined relative to the axial direction, and the outer diameter of the guide surface gradually decreases from the assembly port to the connecting port.

16. The volute assembly according to claim 15, wherein: Along the axial direction, a bearing mounting groove is provided at one end of the air intake guide cover away from the first air collecting chamber, and the bearing mounting groove is used to mount a protective bearing; Along the radial direction, at least a portion of the bearing mounting groove overlaps with the first air collecting chamber.

17. A compressor, characterized in that: The compressor comprises: The volute assembly according to any one of claims 1 to 16, wherein the volute assembly is provided with a shaft mounting hole extending along the axial direction, the shaft mounting hole being in communication with the first compression chamber and the second compression chamber respectively; a first impeller disposed in the first pressurizing chamber; a second impeller disposed in the second pressurizing chamber; The rotor shaft is rotatably inserted into the shaft mounting hole, and part of the rotor shaft is sequentially inserted into the first compression chamber and the second compression chamber, and is connected to the first impeller and the second impeller respectively.

Images