Compressor

Abstract

The invention relates to the technical field of centrifugal compressors, in particular to a compressor. The compressor comprises a shell assembly, a rotating shaft assembly, a protection bearing and an impeller, the rotating shaft assembly is arranged in the shell assembly, a purging channel is formed between the rotating shaft assembly and the shell assembly, the protection bearing is arranged on the rotating shaft assembly in a sleeving mode and located between the rotating shaft assembly and the shell assembly, an airflow gap is formed in the protection bearing, and the impeller is connected with the rotating shaft assembly. And in the axial direction of the rotating shaft assembly, the two opposite sides of the impeller and the shell assembly form an air inlet cavity and a blowing cavity which are communicated, the pressure of the air inlet cavity is larger than that of the blowing cavity, the air inlet end of the blowing channel is communicated with the blowing cavity, and the air outlet end of the blowing channel is communicated with the airflow gap. According to the compressor in the embodiment, airflow enters and penetrates through the airflow gap of the protective bearing along the purging channel, so that possible abrasive dust inside the protective bearing or tiny dust entering from the outside is taken away, and the cleaning effect is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of centrifugal compressors, and in particular to a compressor. Background Art

[0002] Magnetic levitation centrifugal compressors are widely used in central air conditioning, industrial refrigeration, and other fields due to their high efficiency, low noise, and maintenance-free design. These compressors rely on magnetic bearings to achieve contactless operation between the rotor and stator, reducing friction losses and extending equipment life. However, to ensure the system's emergency support capabilities in the event of a magnetic levitation control failure, magnetic levitation compressors are typically equipped with a backup bearing (also known as a protective bearing) to support the rotor in the event of a rotor drop.

[0003] In the prior art, magnetic levitation compressors mostly use a tandem impeller layout, with the backup bearing generally located between the first and second impellers or away from the impellers. In this type of structure, the backup bearing close to the impeller side has a small pressure difference due to the first-stage exhaust and second-stage intake on both sides, making it difficult to form an effective airflow flushing. The backup bearing away from the impeller side has almost no airflow passing through it, resulting in the difficulty of timely discharge of impurities such as debris generated in the bearing during compressor operation, and easily accumulating inside the bearing. This accumulation of impurities will aggravate mechanical shock and wear in the event of a subsequent rotor drop, and in severe cases, may even cause bearing failure.

[0004] In addition, the existing technology generally lacks effective cooling means for the spare bearing. During the rotor falling process, the spare bearing is heated violently, and its life is easily shortened due to excessive local temperature rise, affecting the safety and reliability of the compressor. Summary of the Invention

[0005] The purpose of the present invention is to at least solve the problem of how to clean and protect bearings. This purpose is achieved through the following technical solutions:

[0006] A first aspect of the present invention provides a compressor, comprising:

[0007] housing assembly;

[0008] a rotating shaft assembly, the rotating shaft assembly being disposed in the housing assembly, and a purge channel being formed between the rotating shaft assembly and the housing assembly;

[0009] a protective bearing, the protective bearing being sleeved on the shaft assembly and located between the shaft assembly and the housing assembly, an air flow gap being defined in the protective bearing, and an air inlet and an air outlet being formed at both ends of the air flow gap;

[0010] An impeller is connected to the rotating shaft assembly. Along the axial direction of the rotating shaft assembly, the side of the impeller facing away from the protective bearing and the housing assembly define an air inlet chamber, and the side of the impeller facing the protective bearing and the housing assembly define a purge chamber, the purge chamber is respectively connected to the air inlet chamber and the air inlet end of the purge channel, and the air outlet end of the purge channel is connected to the air inlet of the airflow gap.

[0011] According to the compressor of the present invention, a purge channel is formed between the shell assembly and the shaft assembly, and the purge channel is connected to the air flow gap of the protective bearing, so that gas can flow from the purge chamber into the air flow gap through the purge channel during operation. Since the pressure of the air inlet chamber is higher than that of the purge chamber, a stable purge airflow is formed under the driving action of the pressure difference between the air inlet chamber and the purge chamber. The airflow enters and passes through the air flow gap of the protective bearing along the purge channel. Under normal working conditions without contacting the protective bearing, it forms a continuous flushing effect on the internal structure of the protective bearing (such as the rolling element area), thereby effectively taking away the impurity particles, grinding chips or dust entering from the outside that may remain inside the protective bearing, and playing an active cleaning role. Compared with the existing structure in which the protective bearing is in a closed and static state for a long time, the present invention can significantly reduce the risk of impurity accumulation, avoid instantaneous jamming or damage caused by particles in the rolling contact area during falling conditions, and improve the reliability and response safety of the protective bearing. In addition, the present invention establishes a communication relationship between the purge channel and the airflow gap of the protective bearing, so that in the event of magnetic levitation failure or other abnormal conditions, when the shaft assembly falls and contacts the protective bearing, gas can still continue to flow from the purge chamber through the purge channel and through the airflow gap. During the contact process, the airflow can effectively carry away the heat generated by the high-speed contact friction of the rolling elements, play an active cooling role, and avoid a sharp rise in the temperature of the protective bearing in a short period of time, thereby reducing the risk of thermal failure. Especially in the case of high-speed and large-inertia falls, this cooling mechanism can significantly improve the heat resistance and emergency load-bearing capacity of the protective bearing, extend its service life, and improve the safety and reliability of the entire compressor system.

[0012] In addition, the compressor according to the present invention may also have the following additional technical features:

[0013] In some embodiments of the present invention, the housing assembly includes a seal, which is mounted on the rotating shaft assembly. A comb-tooth sealing structure is formed between the seal and the rotating shaft assembly. Along the axial direction, the seal is located between the impeller and the protective bearing, and part of the purge channel is formed in the comb-tooth sealing structure.

[0014] In some embodiments of the present invention, the seal includes a first comb tooth seal, the shaft assembly includes a shaft body, the first comb tooth seal is sleeved on the shaft body, and the comb tooth seal structure is formed between the first comb tooth seal and the shaft body.

[0015] In some embodiments of the present invention, the seal includes a second comb tooth seal, the shaft assembly includes a shaft body and a sleeve mounted on the shaft body, the second comb tooth seal is mounted on the sleeve, and the comb tooth seal structure is formed between the second comb tooth seal and the sleeve.

[0016] In some embodiments of the present invention, the comb teeth sealing structure includes a plurality of comb teeth, and the plurality of comb teeth are arranged at intervals along the axial direction.

[0017] In some embodiments of the present invention, an annular sealing groove is provided on the circumferential outer wall of the sealing member, a sealing ring is accommodated in the annular sealing groove, and the sealing ring abuts against the annular sealing groove and the housing assembly respectively.

[0018] In some embodiments of the present invention, the housing assembly includes a partition plate, and along the radial direction of the rotating shaft assembly, at least part of the seal is arranged between the partition plate and the rotating shaft assembly, the circumferential side wall of the seal is connected to the circumferential inner wall of the partition plate, and along the axial direction, the partition plate is located between the impeller and the protective bearing.

[0019] In some embodiments of the present invention, a guide groove is provided on one side wall of the impeller facing the purge chamber. Along the axial direction, the guide groove is recessed toward the side away from the protective bearing. Along the direction from the radial outside to the inside of the impeller, the recessed depth of the guide groove first increases and then decreases.

[0020] In some embodiments of the present invention, the maximum depth of the guide groove is at the bottom of the guide groove, and along the axial direction, the bottom is arranged opposite to the sealing component.

[0021] In some embodiments of the present invention, the compressor includes two impellers and two protective bearings, the two impellers are respectively arranged at both ends of the rotating shaft assembly, the two protective bearings are arranged in a one-to-one correspondence with the two impellers, and each protective bearing is connected to the purge chamber of the corresponding impeller through a purge channel.

[0022] In some embodiments of the present invention, the protective bearing includes an outer ring, an inner ring, and a rolling body arranged between the outer ring and the inner ring, the outer ring is connected to the housing assembly, the inner ring is connected to the rotating shaft assembly, and an airflow gap is formed between the inner ring and the outer ring.

[0023] In some embodiments of the present invention, each of the protective bearings includes at least two bearing bodies, each of the bearing bodies is provided with the airflow gap, and along the axial direction, at least two of the protective bearings are arranged in sequence and the airflow gaps of the two bearing bodies are connected.

[0024] In some embodiments of the present invention, an air outlet channel is provided in the shell assembly, and the air outlet channel is respectively connected to the air outlet of the purge channel and the outside of the shell assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] 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. In the accompanying drawings:

[0026] Figure 1 Schematically shows a partial cross-sectional view of a compressor according to a first embodiment of the present invention;

[0027] Figure 2 for Figure 1 A partial enlarged view of point A in the middle;

[0028] Figure 3 for Figure 1 A partial enlarged view of point B in the middle;

[0029] Figure 4 A partial cross-sectional view schematically shows a sealing ring disposed between a sealing member and a housing assembly according to the present invention;

[0030] Figure 5 Schematically shows a partial cross-sectional view of a compressor according to a second embodiment of the present invention;

[0031] Figure 6 The figure schematically shows a structure diagram in which protective bearings and impellers are provided at both ends of the rotating shaft assembly according to the present invention.

[0032] The reference numerals are as follows:

[0033] 211, compressor; 21101, purge channel; 21102, air inlet chamber; 21103, purge chamber; 211031, guide groove;

[0034] 2111, housing assembly; 21111, first comb tooth seal; 211111, comb teeth; 21112, partition plate; 21113, second comb tooth seal; 21114, sealing ring;

[0035] 2112, shaft assembly; 21121, shaft body; 21122, bushing;

[0036] 2113. Protective bearing; 21131. Air flow gap; 21132. Outer ring; 21133. Inner ring; 21134. Rolling element; 2114. Impeller. DETAILED DESCRIPTION

[0037] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure 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 disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0038] 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.

[0039] 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.

[0040] 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 flipped over, an element described as "below" or "beneath" another element or feature would then be oriented "above" or "above" the other element or feature. Thus, the example term "below" can encompass both above and below orientations.

[0041] like Figures 1 to 6 As shown, according to an embodiment of the present invention, a compressor 211 is proposed, which includes a housing assembly 2111, a shaft assembly 2112, a protective bearing 2113 and an impeller 2114, wherein the shaft assembly 2112 is arranged in the housing assembly 2111, and a purge channel 21101 is formed between the shaft assembly 2112 and the housing assembly 2111, the protective bearing 2113 is sleeved on the shaft assembly 2112 and located between the shaft assembly 2112 and the housing assembly 2111, an air flow gap 21131 is provided in the protective bearing 2113, and an air inlet and an air outlet are formed at both ends of the air flow gap 21131, respectively, to blow The air outlet end of the sweep channel 21101 is connected to the air inlet of the air flow gap 21131, the air inlet end of the purge channel 21101 is connected to the purge chamber 21103, the impeller 2114 is connected to the shaft assembly 2112, and along the axial direction of the shaft assembly 2112, the side of the impeller 2114 facing the protective bearing 2113 and the housing assembly 2111 define the purge chamber 21103, and the side of the impeller 2114 facing away from the protective bearing 2113 and the housing assembly 2111 define the air inlet chamber 21102, the air inlet chamber 21102 and the purge chamber 21103 are connected, and the pressure of the air inlet chamber 21102 is greater than the pressure of the purge chamber 21103.

[0042] According to the compressor 211 of this embodiment, a purge channel 21101 is formed between the shell assembly 2111 and the shaft assembly 2112, and the air outlet end of the purge channel 21101 is connected to the air flow gap 21131 of the protective bearing 2113, so that gas can flow from the purge chamber 21103 into the air flow gap 21131 via the purge channel 21101 during operation. Since the pressure of the air inlet chamber 21102 is higher than that of the purge chamber 21103, a stable purge airflow is formed under the driving action of the pressure difference between the air inlet chamber 21102 and the purge chamber 21103. The airflow enters and passes through the air flow gap 21131 of the protective bearing 2113 along the purge channel 21101, and forms a continuous flushing effect on the internal structure of the protective bearing 2113 (such as the rolling element 21134 area) under normal working conditions without contacting the protective bearing 2113, thereby effectively taking away impurity particles, wear debris or dust entering from the outside that may remain inside the bearing, thereby playing an active cleaning role.

[0043] Compared to existing structures in which protective bearing 2113 remains sealed and stationary for extended periods, the present invention significantly reduces the risk of impurity accumulation, preventing instantaneous jamming or damage caused by particles already present in the rolling contact area during a drop, thereby improving the reliability and safety of protective bearing 2113. Furthermore, by establishing a connection between purge channel 21101 and airflow gap 21131 of protective bearing 2113, the present invention ensures that, even in the event of magnetic levitation failure or other abnormalities, gas can continue to flow from purge chamber 21103 through purge channel 21101 and through airflow gap 21131 during the process of shaft assembly 2112 falling and contacting protective bearing 2113.

[0044] During contact, this airflow effectively removes heat generated by high-speed friction from rolling element 21134, providing active cooling and preventing a rapid temperature rise in protective bearing 2113, thereby reducing the risk of thermal failure. This cooling mechanism significantly improves the thermal stability and emergency load-bearing capacity of protective bearing 2113, extending its service life and enhancing the safety and reliability of the entire compressor 211 system, particularly during high-speed, high-inertia drops.

[0045] In some embodiments, the housing assembly 2111 includes a seal that is sleeved around the outer circumference of the shaft assembly 2112, with a gap between the seal and the shaft assembly 2112. The circumferential inner wall of the seal opposes the circumferential outer wall of the shaft assembly 2112, forming a comb-shaped seal structure with multiple sealing teeth. The seal is arranged along the axial direction of the shaft assembly 2112 between the impeller 2114 and the protective bearing 2113 to prevent leakage of high-pressure gas from the impeller 2114 to the protective bearing 2113 area.

[0046] Part of the purge channel 21101 is formed within the comb-tooth seal structure, allowing leaked gas to flow through the purge channel 21101 to the airflow gap 21131 region of the protective bearing 2113. In this embodiment, by providing a comb-tooth seal structure between the impeller 2114 and the protective bearing 2113, with the purge channel 21101 located within the comb-tooth seal structure, some of the gas leaking from the high-pressure region on the outlet side of the impeller 2114 can be fully utilized to drive the purge flow, eliminating the need for an additional air bleed device. While maintaining a seal, the comb-tooth seal structure allows some high-pressure gas to enter the purge channel 21101 through a controllable leakage path and flow along the purge channel 21101 to the airflow gap 21131 of the protective bearing 2113.

[0047] This embodiment effectively utilizes previously useless leaked gas as a clean or cooling air source, improving system energy efficiency. Furthermore, the seal positioned between impeller 2114 and protective bearing 2113 creates a more compact airflow path and faster response, enhancing the environmental stability and thermal management capabilities of protective bearing 2113 during operation and drops.

[0048] like Figure 2 As shown, specifically, the comb tooth sealing structure includes a plurality of comb teeth 211111 arranged at intervals along the axial direction of the rotating shaft assembly 2112, each comb tooth 211111 protrudes from the circumferential inner wall of the seal toward the outer periphery of the rotating shaft assembly 2112, and a preset gap is maintained between the comb teeth 211111 and the rotating shaft assembly 2112, and the plurality of comb teeth 211111 form a multi-stage gap sealing structure in sequence, which is used to form step-by-step throttling and disturbance for the gas leaking along the axial direction.

[0049] By adopting multiple comb teeth 211111 arranged at intervals along the axial direction, a multi-stage non-contact sealing path can be formed between the shaft assembly 2112 and the seal. The gaps between the comb teeth 211111 at each stage will cause the leaked gas to expand, contract, and turbulent, thereby causing pressure loss at each stage. This design of step-by-step pressure drop and disturbance enhancement gives the overall comb tooth sealing structure excellent sealing performance, effectively limiting the rate of high-pressure gas leakage to the low-pressure area, and when necessary, introducing controllable leakage gas into the purge channel 21101 for use as cooling or cleaning airflow. Compared with the single-stage structure, the multi-stage comb tooth 211111 arrangement not only improves the sealing efficiency, but also enhances the adaptability to gas disturbances and flow rates under different working conditions, helping to improve the overall operational stability and sealing reliability of the system.

[0050] like Figure 2Specifically, the housing assembly 2111 includes a partition plate 21112, which extends radially along the shaft assembly 2112. At least a portion of the seal is sandwiched between the partition plate 21112 and the shaft assembly 2112 along the radial direction of the shaft assembly 2112. Separator plate 21112 is also disposed axially between the impeller 2114 and the protective bearing 2113 to achieve functional isolation and structural support.

[0051] By arranging the seal to be sandwiched between the partition plate 21112 and the rotating shaft assembly 2112, a stable supporting and positioning structure can be formed around the seal, ensuring its installation firmness in the radial direction and the crimping stability of the sealing ring 21114. As a static structure, the partition plate 21112 not only provides an assembly reference for the seal, but also facilitates the cooperation of the sealing groove, sealing ring 21114 and other structures with it to form a static sealing interface. In addition, the partition plate 21112 is arranged axially between the impeller 2114 and the protective bearing 2113, which not only physically separates the high-pressure impeller 2114 outlet from the low-pressure bearing area, inhibiting the direct leakage of high-pressure gas into the bearing area, but also facilitates the guidance of the airflow leaking from the impeller 2114 side through the purge channel 21101 into the protective bearing 2113 area, thereby enhancing the path controllability of the cooling and cleaning airflow. This structure helps to improve the efficiency of airflow organization and the stability of the operating environment of the protective bearing 2113, further enhancing the safety and reliability of the compressor 211.

[0052] like Figure 4 As shown, specifically, an annular sealing groove is provided on the circumferential outer wall of the seal, and a sealing ring 21114 is accommodated in the annular sealing groove. The sealing ring 21114 and the annular sealing groove are in interference fit, and the radial outer side of the sealing ring 21114 abuts against the stationary structure in the shell assembly 2111.

[0053] Preferably, the sealing ring 21114 abuts against the partition plate 21112 in the housing assembly 2111 to form a static sealing structure between the sealing member and the partition plate 21112 .

[0054] Preferably, the sealing ring 21114 is squeezed by 15% to 30% when it abuts against the partition plate 21112 and the annular sealing groove.

[0055] Preferably, the sealing ring 21114 is an O-ring 21114.

[0056] In this embodiment, an annular sealing groove is provided on the circumferential outer wall of the seal, and a sealing ring 21114 is embedded therein, so that one side of the sealing ring 21114 is tightly fitted with the sealing groove and the other side is crimped to the partition plate 21112 in the housing assembly 2111, thereby establishing a radial sealing interface between the stationary parts between the seal and the partition plate 21112. This structure not only achieves efficient sealing without adding additional connecting parts, but also adapts to slight manufacturing tolerances and thermal expansion and contraction deformation to ensure sealing reliability. At the same time, since the seal and the partition plate 21112 are both stationary parts, the sealing interface will not produce relative movement, and a standard sealing ring 21114 such as an O-ring can be used to achieve a long-life, low-maintenance static seal, effectively preventing compressed gas from leaking from the interface between the seal and the housing assembly 2111, thereby improving the sealing integrity and energy efficiency of the system.

[0057] This embodiment includes two embodiments. One is an embodiment in which the seal is directly sleeved on the shaft body 21121, and the other is an embodiment in which the seal is sleeved on the bushing 21122 on the shaft body 21121. The following are specific implementations of the two embodiments:

[0058] like Figure 5 As shown, in the first embodiment, the seal includes a first comb-tooth seal 21111, and the rotating shaft assembly 2112 includes only a rotating shaft body 21121. The first comb-tooth seal 21111 is directly sleeved onto the outer circumferential surface of the rotating shaft body 21121. The circumferential inner wall of the first comb-tooth seal 21111 is arranged opposite the circumferential outer wall of the rotating shaft body 21121, and a plurality of sealing teeth are formed in an axial direction at intervals, thereby forming a comb-tooth seal structure between the first comb-tooth seal 21111 and the rotating shaft body 21121.

[0059] In this embodiment, for reasons of structural compactness and ease of manufacturing, it's inconvenient to add a bushing 21122 to the exterior of the rotating shaft body 21121. Therefore, bushing 21122 is omitted, and instead, protective bearing 2113 is positioned directly behind the comb-teeth seal structure on the back side of impeller 2114. With this structure, leakage air flowing through the comb-teeth seal structure cannot be precisely guided to the rolling contact area of ​​protective bearing 2113 via the dedicated guide grooves 211031. Therefore, the airflow path is limited by the natural gap between protective bearing 2113 and rotating shaft body 21121.

[0060] Specifically, a certain radial clearance must be reserved between the rotating motor shaft and the stationary protective bearing 2113 to prevent interference or friction during normal operation. This radial clearance provides a partial channel for airflow. Part of the airflow from the comb seal can flow through the radial clearance between the inner ring 21133 of the protective bearing 2113 and the rotating shaft body 21121, while another portion of the airflow can pass through the airflow gap 21131, continuously flushing the ball bearings or raceway area. Although the airflow guidance under this structure is not as clear as that of the structure with bushing 21122, it still has a certain cleaning and cooling effect.

[0061] In particular, when the gap between the protective bearing 2113 and the rotating shaft body 21121 is designed to be smaller, the airflow is more easily concentrated through the airflow gap 21131, thereby enhancing local cleaning and cooling capabilities and helping to improve the operating environment and load-bearing capacity of the protective bearing 2113. However, the smaller the gap, the higher the control accuracy and response requirements of the magnetic levitation bearing, which increases the difficulty of the control system. Therefore, based on the system performance requirements and control capabilities, an appropriate radial gap value can be selected between the bearing and the rotating shaft body 21121. Under the premise of ensuring stable operation of the magnetic levitation, the airflow utilization efficiency can be maximized to achieve better cooling and cleaning effects for the protective bearing 2113.

[0062] like Figures 1 to 3 As shown, in the second embodiment, the seal includes a second comb-tooth seal 21113, and the shaft assembly 2112 includes a shaft body 21121 and a bushing 21122 sleeved on the outer circumference of the shaft body 21121. The second comb-tooth seal 21113 is sleeved on the outer circumferential surface of the bushing 21122, and a predetermined gap is provided between the circumferential inner wall of the second comb-tooth seal 21113 and the circumferential outer wall of the bushing 21122. A plurality of comb teeth 211111 are arranged in the axial direction in the gap area, thereby forming a comb-tooth seal structure between the second comb-tooth seal 21113 and the bushing 21122.

[0063] By installing a bushing 21122 on the shaft assembly 2112, a sealed flow path is formed between it and the second comb seal 21113, guiding leaked gas from the high-pressure side of the impeller 2114 along a predetermined path. The purge channel 21101 is structurally optimized so that its outlet area faces the airflow gap 21131 between the inner and outer rings 21132 of the protective bearing 2113, where the rolling elements 21134 are located. This ensures that the airflow passing through this area directly impacts the key components of the protective bearing 2113, such as the balls and raceways.

[0064] During operation, the gas flowing through the comb seal enters the sealing flow path (i.e., the purge channel 21101) driven by the pressure difference, and steadily flushes the rolling element 21134 area of ​​the protective bearing 2113 from its outlet, forming a continuous cleaning effect, which helps to remove foreign particles generated by the environment or wear, and prevent them from being drawn into the contact surface in the falling state and causing jamming or damage.

[0065] Furthermore, purge channel 21101 provides a certain degree of cooling, reducing the risk of localized heat accumulation in protective bearing 2113 and increasing the service life and operational reliability of protective bearing 2113. Therefore, this second embodiment structurally achieves the advantages of a clear cleaning path, concentrated cleaning effect, and no need for additional air bleed structures, making it a preferred solution for reliably cleaning protective bearing 2113.

[0066] like Figure 1 As shown, in some embodiments, a guide groove 211031 is provided on the wall surface of the impeller 2114 facing the purge chamber 21103. Along the axial direction of the rotating shaft assembly 2112, the guide groove 211031 is recessed toward the side away from the protective bearing 2113. The depth of the recessed guide groove 211031 increases and then decreases from the radially outer side to the inner side of the impeller 2114. Providing the guide groove 211031 on the wall surface of the impeller 2114 facing the purge chamber 21103 allows the gas to be pre-directed into a controlled flow direction as it flows from the outlet region of the impeller 2114 into the purge chamber 211031, preventing turbulent or disordered airflow and improving gas transport efficiency.

[0067] Furthermore, the maximum depth of guide groove 211031 is at its bottom, which is located opposite the seal along the axial direction of shaft assembly 2112. Specifically, the bottom of guide groove 211031 is located near the inlet of purge channel 21101, extending from the outlet of impeller 2114 to near the seal, forming a gradually deepening and then shallowing groove structure. This serves to redirect airflow, deflecting and channeling gas that would otherwise swirl or diffuse along the inner wall of housing assembly 2111 into purge channel 21101.

[0068] By providing a guide groove on the inner wall of purge chamber 21103, the direction and speed of the airflow entering purge chamber 21103 can be guided, and the speed can be adjusted to prevent turbulence or local stagnation of the airflow within purge chamber 21103. The guide groove 211031 enables the gas to naturally converge along a preset path as it flows through purge chamber 21103 and be precisely introduced into the air inlet end of purge channel 21101, thereby improving the stability and efficiency of the airflow flowing into purge channel 21101. Compared to a smooth inner wall design without guide groove 211031, the use of guide groove 211031 can significantly improve the air capture capacity of the air inlet end of purge channel 21101, increase the utilization rate of the airflow for cleaning and cooling, and reduce the system's reliance on pressure differentials, helping to maintain the cleaning and cooling effects of the area protecting bearing 2113 under different operating conditions.

[0069] like Figure 6 As shown, in some embodiments, the compressor 211 includes two impellers 2114 and two protective bearings 2113, which are respectively used to realize symmetrical or two-stage compression functions. The two impellers 2114 are respectively arranged at both ends of the rotating shaft body 21121, and the two protective bearings 2113 are arranged in a one-to-one correspondence with the two impellers 2114. Each protective bearing 2113 is connected to the corresponding purge chamber 21103 of an impeller 2114 through the air inlet of a purge channel 21101.

[0070] By providing impellers 2114 and protective bearings 2113 at either end of the rotating shaft assembly 2112, a symmetrical compression and drop support structure is constructed. This not only improves the overall dynamic balance and compression efficiency of the rotor, but also provides effective support on both sides in the event of a magnetic levitation system failure, enhancing system safety. Furthermore, each protective bearing 2113 is provided with an independent purge channel 21101, which communicates with the purge chamber 21103 on the adjacent impeller 2114 side, forming two independent cooling and cleaning airflow channels. This structure ensures that both protective bearings 2113 receive continuous, directional airflow during operation or drop, effectively removing impurities and heat from the bearing area and preventing abnormal bearing wear or thermal failure. Compared to solutions with only one purge channel 21101, this embodiment achieves the advantages of functional symmetry, structural independence, and rapid response in the cooling path, further enhancing the emergency protection capability and structural reliability of the compressor 2111 under abnormal operating conditions.

[0071] like Figure 3As shown, in some embodiments, the protective bearing 2113 includes an outer ring 21132, an inner ring 21133, and rolling elements 21134 disposed between the outer and inner rings 21132 and 21133. The rolling elements 21134 are preferably balls or rollers. The outer ring 21132 is fixedly connected to the stationary component of the housing assembly 2111. The inner ring 21133 is connected to the shaft assembly 2112 and contacts the shaft assembly 2112 in the event of a magnetic levitation system failure, providing emergency support for the shaft. An airflow gap 21131 is defined between the inner and outer rings 21133 and 21132. The airflow gap 21131 is formed in the area of ​​the rolling elements 21134 to clean and cool the rolling elements 21134 and their working area when air flows through the gap.

[0072] By incorporating a typical rolling bearing structure, including an outer ring 21132, an inner ring 21133, and rolling elements 21134, within protective bearing 2113, reliable mechanical support is provided in the event of a magnetic levitation system failure and the shaft falling. Outer ring 21132 is fixed to housing assembly 2111, ensuring a stable bearing position. Inner ring 21133, connected to shaft assembly 2112, only withstands transient contact loads during a fall, maintaining a contact-free, friction-free operating state during normal operation and extending the overall system lifespan.

[0073] Specifically, an airflow gap 21131 is provided between outer ring 21132 and inner ring 21133. This allows cleaning or cooling gas to pass through the rolling element 21134 region under the influence of a pressure differential, effectively flushing out microparticles in the bearing and removing heat generated by friction during contact. This significantly improves the cleanliness and thermal stability of the bearing in a dropped state. This embodiment not only provides structural redundancy support for protective bearing 2113, but also enables self-cleaning and thermal management capabilities in the operating environment, enhancing its reliability and lifespan under extreme operating conditions.

[0074] In some embodiments, the protective bearing 2113 includes at least two bearing bodies, each bearing body is provided with an airflow gap 21131, and the bearing bodies of the two protective bearings 2113 are sequentially arranged at the same end of the rotating shaft assembly 2112 and are interconnected to form an integrated dual-bearing arrangement structure.

[0075] Preferably, the bearing bodies of the two protective bearings 2113 are abutted together via a seal and a mounting plate of the housing assembly 2111. The seal abuts one side of one of the protective bearings 2113, and the mounting plate abuts the other side of the other protective bearing 2113.

[0076] Furthermore, the airflow gaps 21131 between the two protective bearings 2113 are connected, guiding the gas in the purge channel 21101 to flow sequentially through the rolling element 21134 regions of the two protective bearings 2113. This embodiment achieves dual protective support at this end by placing the two protective bearings 2113 in series at one end of the rotating shaft assembly 2112 and using a structural connection to achieve integrated positioning.

[0077] Compared with a single bearing structure, this design can share the local contact load when the shaft falls, enhance the impact resistance, and is particularly suitable for high-speed, large-inertia compression systems. In addition, the airflow gaps 21131 of the two protective bearings 2113 remain connected, forming a continuous cleaning and cooling air path. After the gas is introduced through the purge channel 21101, it can continuously flush the rolling element 21134 area of ​​the two protective bearings 2113, improving the cleaning effect and cooling coverage. This design avoids the complex layout of multiple branch channels, making the cooling structure more compact and the airflow utilization efficiency higher. In summary, this embodiment effectively improves the local support redundancy, cleaning uniformity and heat dissipation capacity by arranging the double bearings in series at the end and the through-airflow gap 21131, providing a preferred solution for high-reliability compressor systems.

[0078] In some embodiments, an air outlet channel is provided within the housing assembly 2111. The outlet channel's inlet communicates with the air outlet of the purge channel 21101, while the outlet communicates with the exterior of the housing assembly 2111. The outlet channel is used to direct the gas flowing through the protective bearing 2113 to the exterior of the system or to another predetermined area. Preferably, the outlet channel is a built-in gas guide groove or gas collection cavity provided on the housing assembly 2111, either integrally formed or in a segmented configuration, maintaining fluid communication with the purge channel 21101.

[0079] In some embodiments, the housing assembly 2111 is provided with a first step portion, and the shaft assembly 2112 is provided with a second step portion that cooperates therewith. The first step portion and the second step portion are structurally staggered with each other to form a step-matching structure.

[0080] Through the above-described structural coordination, the purge channel 21101 exhibits a stepped path in the stepped region, i.e., the channel exhibits at least one abrupt cross-sectional change or flow path bend along the airflow direction. Preferably, a first step is formed on the inner wall of the housing assembly 2111, and a second step is formed on the outer circumference of the shaft assembly 2112 or the outer surface of the bushing 21122. The two form a predetermined clearance fit in the radial or axial directions, thereby constructing a localized purge channel 21101 with both flow blocking and guiding functions. By providing the first and second steps, which cooperate with each other, between the housing assembly 2111 and the shaft assembly 2112, the purge channel 21101 exhibits a stepped structure in this region, effectively disrupting, limiting, or throttling the gas flow path. On the one hand, the stepped path helps disrupt local laminar flow, increasing gas turbulence, and providing enhanced cleaning and flushing capabilities for the gas entering the protective bearing 2113. On the other hand, this structure can also suppress reverse backflow, regulate local flow velocity and pressure gradients, and improve the airflow control precision of the purge channel 21101.

[0081] 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 compressor, characterized in that: include: housing assembly; a rotating shaft assembly, the rotating shaft assembly being disposed in the housing assembly, and a purge channel being formed between the rotating shaft assembly and the housing assembly; a protective bearing, the protective bearing being sleeved on the shaft assembly and located between the shaft assembly and the housing assembly, an air flow gap being defined in the protective bearing, and an air inlet and an air outlet being formed at both ends of the air flow gap; An impeller is connected to the rotating shaft assembly. Along the axial direction of the rotating shaft assembly, the side of the impeller facing away from the protective bearing and the housing assembly define an air inlet chamber, and the side of the impeller facing the protective bearing and the housing assembly define a purge chamber, the purge chamber is respectively connected to the air inlet chamber and the air inlet end of the purge channel, and the air outlet end of the purge channel is connected to the air inlet of the air flow gap.

2. The compressor according to claim 1, characterized in that The housing assembly includes a seal, which is sleeved on the shaft assembly. A comb-tooth seal structure is formed between the seal and the shaft assembly. Along the axial direction, the seal is located between the impeller and the protective bearing, and part of the purge channel is formed in the comb-tooth seal structure.

3. The compressor according to claim 2, characterized in that The seal includes a first comb-tooth seal, the shaft assembly includes a shaft body, the first comb-tooth seal is sleeved on the shaft body, and the comb-tooth seal structure is formed between the first comb-tooth seal and the shaft body.

4. The compressor according to claim 2, characterized in that The seal includes a second comb tooth seal, the shaft assembly includes a shaft body and a bushing sleeved on the shaft body, the second comb tooth seal is sleeved on the bushing, and the comb tooth seal structure is formed between the second comb tooth seal and the bushing.

5. The compressor according to claim 2, characterized in that The comb teeth sealing structure includes a plurality of comb teeth, and the plurality of comb teeth are arranged at intervals along the axial direction.

6. The compressor according to claim 2, characterized in that An annular sealing groove is provided on the circumferential outer wall of the sealing member. A sealing ring is accommodated in the annular sealing groove. The sealing ring abuts against the annular sealing groove and the housing assembly respectively.

7. The compressor according to claim 2, characterized in that The housing assembly includes a partition plate. Along the radial direction of the rotating shaft assembly, at least part of the seal is arranged between the partition plate and the rotating shaft assembly. The circumferential side wall of the seal cooperates with the circumferential inner wall of the partition plate, and along the axial direction, the partition plate is located between the impeller and the protective bearing.

8. The compressor according to claim 2, characterized in that A guide groove is provided on the wall surface of one side of the impeller facing the purge chamber. Along the axial direction, the guide groove is recessed toward the side away from the protective bearing. Along the direction from the radial outer side to the inner side of the impeller, the recessed depth of the guide groove first increases and then decreases.

9. The compressor according to claim 8, characterized in that Along the axial direction, the maximum recessed depth of the guide groove is at the bottom of the guide groove. Along the axial direction, the bottom is arranged opposite to the sealing component.

10. The compressor according to any one of claims 1 to 9, characterized in that The compressor includes two impellers and two protective bearings. The two impellers are respectively arranged at both ends of the rotating shaft assembly. The two protective bearings are arranged in a one-to-one correspondence with the two impellers. Each protective bearing is connected to the purge chamber of the corresponding impeller through a purge channel.

11. The compressor according to any one of claims 1 to 9, characterized in that The protective bearing includes an outer ring, an inner ring, and a rolling body arranged between the outer ring and the inner ring. The outer ring is connected to the housing assembly, the inner ring is connected to the shaft assembly, and the airflow gap is formed between the inner ring and the outer ring.

12. The compressor according to any one of claims 1 to 9, characterized in that Each of the protective bearings includes at least two bearing bodies, each of the bearing bodies is provided with the airflow gap, and along the axial direction, at least two of the protective bearings are arranged in sequence and the airflow gaps of the two bearing bodies are connected.

13. The compressor according to any one of claims 1 to 9, characterized in that An air outlet channel is provided in the shell assembly, and the air outlet channel is connected to the air outlet of the purge channel and the outside of the shell assembly respectively.

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