Single stage centrifugal air compressor

Abstract

The application provides a single-stage centrifugal air compressor, and an air path cooling system of the single-stage centrifugal air compressor comprises a first cooling air path and a second cooling air path; the first cooling air path comprises a shell cooling air passage; an annular passage; a plurality of bearing seat air inlet holes; a cover cavity provided with a total air outlet; a bearing seat air outlet hole communicated between a first radial air floating bearing of a motor away from a volute and a matching gap of a motor stator and the cover cavity; the second cooling air path comprises an impeller back and a shell end surface air inlet gap close to the impeller of the shell in sequence, a matching gap of a second radial air floating bearing of the motor close to the volute and a main shaft, a matching gap of the stator and the main shaft, a matching gap of the stator and the first radial air floating bearing and the bearing seat air outlet hole, and the air inlet gap is communicated with an air outlet side of the impeller. The first cooling air path and the second cooling air path can cool rotor components at different positions of the motor respectively, improve the cooling effect of the rotor components of the motor, and ensure the use performance of the motor.

Description

Technical Field

[0001] This application relates to the field of air compressor cooling technology, specifically to a single-stage centrifugal air compressor. Background Technology

[0002] High-speed centrifugal air compressors are mainly used to boost air pressure in air supply systems. They achieve this by directly driving the compressor impeller to rotate through the high-speed rotation of the motor spindle. The motor spindle is supported at both ends by radial air bearings.

[0003] In related technologies, the rotor components such as the motor main shaft and bearings are cooled sequentially along the axial direction by the gas leaking from the back of the impeller. However, the cooling effect on the bearings far from the impeller is poor, which affects the performance of the motor.

[0004] Secondly, the gas leaking from the impeller back is at a high temperature after compression, resulting in poor cooling of the rotor components and making the rotor more prone to demagnetization due to high temperature, thus affecting its service life. Furthermore, additional bleed air solutions would increase the overall cost of the machine.

[0005] Furthermore, the non-outlet end of the ultra-high speed motor near the impeller is the main high temperature point. Related technologies use radial cooling water to cool the motor, which results in low heat exchange efficiency at the motor end near the impeller and poor cooling effect at the motor end, thus affecting the motor's service life and peak power.

[0006] In addition, high-speed centrifugal air compressors have a large axial force. Related technologies use large-sized thrust bearings to balance this axial force, which results in greater heat generation in the thrust bearings, requiring increased cooling airflow and causing a decrease in overall machine efficiency. Larger thrust bearings also increase the overall size, weight, and cost of the machine. Summary of the Invention

[0007] The purpose of this application is to provide a single-stage centrifugal air compressor to improve the cooling effect on the motor rotor components and ensure the performance of the motor.

[0008] To achieve the above objectives, this application provides the following technical solution: A single-stage centrifugal air compressor includes a compressor and a motor; it also includes an air cooling system, wherein the air cooling system comprises a first cooling air passage and a second cooling air passage, wherein... The first cooling air path includes: A housing cooling air passage is provided in the housing of the motor and extends from one end near the volute of the compressor to the other end away from the volute. The housing cooling air passage has a housing air inlet that communicates with the volute chamber of the volute at the end near the volute and a housing air outlet at the end away from the volute. An annular channel is provided at the connection between the bearing seat and the housing at the end of the motor away from the volute, and the annular channel is connected to the air outlet of the housing; Multiple bearing housing air inlets are provided in the bearing housing and distributed circumferentially along the bearing housing. The bearing housing air inlets are connected between the mating clearance between the bearing housing and the spindle and the annular channel. A housing cavity is provided in the housing of the motor, and the housing cavity is provided with a main air outlet; An air vent is provided in the bearing housing, extending axially. The air vent is connected between the first radial air bearing at the end of the motor away from the volute and the mating clearance of the motor stator and the cavity of the housing. The second cooling air path includes: The compressor's impeller back and the housing end face near the impeller's air intake gap are connected in sequence; the second radial air bearing of the motor near the volute end and the main shaft's fit gap are connected in sequence; the motor stator and the main shaft's fit gap are connected in sequence; the motor stator and the first radial air bearing's fit gap are connected in sequence; and the bearing seat's air outlet is connected in sequence. The air intake gap is connected to the impeller's air outlet side.

[0009] Optionally, the above-mentioned single-stage centrifugal air compressor further includes a water cooling system, wherein the water cooling system includes: A water-cooling channel is provided at the end of the housing near the volute. The water-cooling channel at the end of the housing is provided with a water inlet and a water outlet. The water inlet is connected to a water inlet connector. A circumferential water-cooling channel is formed along the circumference of the housing and extends from one end near the volute to the other end away from the volute. The inlet of the circumferential water-cooling channel near the volute is connected to the water outlet, and the outlet at the end away from the volute is connected to a water outlet connector.

[0010] Optionally, in the above-mentioned single-stage centrifugal air compressor, the water-cooling channel at the end of the casing and the projection of the air intake gap along the motor axis at least partially overlap; And / or, the circumferential water cooling channel of the housing and the cooling air channel of the housing at least partially overlap along the radial direction of the motor.

[0011] Optionally, in the above-mentioned single-stage centrifugal air compressor, a heat exchange groove is provided on the end face of the casing facing the air inlet gap.

[0012] Optionally, in the above-mentioned single-stage centrifugal air compressor, the water-cooling channel at the end of the casing covers the entire circumference of the end of the casing, and a cooling water isolation is provided in the water-cooling channel at the end of the casing to seal and separate the water inlet and the water outlet. The cooling water isolation is provided with a water flow guide surface on at least one side to facilitate the flow of water entering through the inlet hole to the outlet hole.

[0013] Optionally, in the above-mentioned single-stage centrifugal air compressor, the motor includes a thrust plate disposed at the end of the first radial air bearing away from the volute, with air-bearing thrust bearings disposed at both ends of the thrust plate, and a thrust adjustment block disposed on the bearing housing and fitted around the thrust plate, the thrust adjustment block and the thrust plate being sealed together by a labyrinth seal structure.

[0014] Optionally, in the above-mentioned single-stage centrifugal air compressor, the first cooling air path further includes: The fitting clearances of the first air-bearing thrust bearing and the bearing housing, the fitting clearances of the labyrinth seal structure, the fitting clearances of the second air-bearing thrust bearing and the bearing back plate, and the fitting clearances of the bearing back plate and the main shaft are connected in sequence. Wherein, the fitting clearance between the first air-bearing thrust bearing and the bearing housing is connected to the air inlet of the bearing housing, and the fitting clearance between the bearing back plate and the main shaft is connected to the cavity of the cover. The first air-bearing thrust bearing is an air-bearing thrust bearing located at the end of the thrust disk near the bearing housing; the second air-bearing thrust bearing is an air-bearing thrust bearing located at the end of the thrust disk away from the bearing housing; the bearing back plate is disposed at the end of the second air-bearing thrust bearing away from the thrust disk.

[0015] Optionally, in the above-mentioned single-stage centrifugal air compressor, the labyrinth seal structure includes: Multiple rings of annular sealing teeth are provided on the outer circumferential surface of the thrust disk, and the annular sealing teeth are distributed along the axial direction of the thrust disk; Multiple sealing grooves are formed on the inner circumferential surface of the thrust adjustment block. The sealing grooves are distributed along the axial direction of the thrust adjustment block, and the annular sealing teeth are in clearance fit with the sealing grooves in a one-to-one correspondence.

[0016] Optionally, in the above-mentioned single-stage centrifugal air compressor, the casing cooling air passage includes multiple branch passages connected end to end, the multiple branch passages being arranged circumferentially along the casing and located near the outlet of the volute.

[0017] Optionally, in the above-mentioned single-stage centrifugal air compressor, the casing is provided with a casing return air passage; the housing is provided with a housing return air passage, and the volute is provided with a volute return air passage; The main air outlet, the cover return air channel, the housing return air channel, the volute return air channel, and the compressor inlet are connected in sequence.

[0018] In the single-stage centrifugal air compressor provided in this application, the air cooling system cools the motor rotor components through a first cooling air path and a second cooling air path.

[0019] When the first cooling air path is working, the high-pressure gas generated by the impeller rotation flows from the volute chamber of the volute into the cooling air channel of the housing through the housing air inlet, and then enters the annular channel through the housing air outlet. It then flows through multiple bearing seat air inlets to the mating clearance between the bearing seat and the main shaft. From this mating clearance, it flows sequentially through the mating clearance between the first radial air bearing and the main shaft, and the mating clearance between the first radial air bearing and the motor stator. Finally, it converges into the cover cavity through the bearing seat air outlet and flows out from the main air outlet of the cover cavity. This allows the high-pressure gas in the volute chamber to be diverted to the first radial air bearing at the end of the motor away from the volute, thus cooling the rotor components at the end of the motor away from the volute chamber separately. When the second cooling air path is working, the high-pressure gas generated by the impeller rotation flows from the outlet side of the impeller into the air inlet gap between the back of the impeller and the end face of the casing. Then, it flows sequentially through the fitting gap between the second radial air bearing and the main shaft, the fitting gap between the motor stator and the main shaft, and the fitting gap between the motor stator and the first radial air bearing. Finally, it converges into the casing cavity through the bearing seat outlet and flows out from the main outlet of the casing cavity. This can guide the high-pressure gas on the back of the impeller to the second radial air bearing and the main shaft near the volute end of the motor, and can cool the rotor components away from the volute end of the motor.

[0020] Therefore, this application draws two airflows from the high-pressure gas generated by the impeller's rotation. One airflow is introduced into the first cooling air path through the volute chamber of the volute, which can cool the rotor components of the motor away from the volute separately, preventing the airflow temperature at this end of the rotor from being too high and affecting the heat exchange effect. The other airflow is introduced into the second cooling air path through the impeller's outlet side, which can cool the rotor components other than the end of the motor away from the volute. In this way, the first and second cooling air paths can cool different parts of the rotor components of the motor separately, improving the cooling effect on the motor rotor components and ensuring the motor's performance. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be introduced below. The accompanying drawings described below are merely embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0022] Figure 1 A schematic diagram of an exemplary single-stage centrifugal air compressor consistent with some embodiments of this application is shown.

[0023] Figure 2 It shows Figure 1 A magnified view of part A in the middle.

[0024] Figure 3 A schematic cross-sectional view of the water-cooling channel at the end of the casing of an exemplary single-stage centrifugal air compressor, consistent with some embodiments of this application, is shown.

[0025] The above Figures 1-3 middle: 1-Vortex casing; 101-Vortex chamber; 2-Casing; 201-Casing end face; 202-Casing cooling air passage; 203-Casing return air passage; 204-Casing end water cooling passage; 205-Water inlet; 206-Cooling water isolation; 207-Water outlet; 208-Casing circumferential water cooling passage; 3-Motor stator; 4-Cover; 401-Cover cavity; 5-Bearing back plate; 6-Thrust plate; 7-Air-float thrust bearing; 8-Bearing housing; 801-Bearing housing air inlet; 802-Annular channel; 803-Bearing housing air outlet; 9-First radial air-float bearing; 10-Second radial air-float bearing; 11-Main shaft; 12-Impeller; 13-Water inlet connector; 14-Water outlet connector; 15-Thrust adjustment block. Detailed Implementation

[0026] The embodiments of this application will be described below. It should be noted that, in order to provide a concise description of these embodiments, this specification cannot provide a detailed description of all features of the actual embodiments. It should be understood that, in the actual implementation of any embodiment, changes may occur from one embodiment to another to achieve specific objectives. Furthermore, it is also understood that, although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content of this application, some design, manufacturing, or production modifications based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient content of this application.

[0027] like Figures 1-3 As shown, the single-stage centrifugal air compressor provided in this application embodiment includes a compressor and a motor. Specifically, the compressor includes an impeller 12 and a volute 1 with a volute chamber 101. The motor includes a housing 2, a motor stator 3, a main shaft 11, a cover 4, an air-bearing thrust bearing 7, a bearing housing 8, a first radial air-bearing bearing 9, and a second radial air-bearing bearing 10.

[0028] The single-stage centrifugal air compressor provided in this application embodiment also includes an air cooling system, which includes a first cooling air path and a second cooling air path. The first cooling air path includes: a housing cooling air passage 202, which is located in the motor housing 2 and extends from one end near the compressor volute 1 to the end away from the volute 1. The housing cooling air passage 202 has a housing 2 air inlet at the end near the volute 1 that communicates with the volute chamber 101 of the volute 1, and a housing 2 air outlet at the end away from the volute 1; an annular channel 802, located at the connection between the bearing seat 8 and the housing 2 at the end of the motor away from the volute 1, and communicating with the housing 2 air outlet; and multiple bearing seats. An air inlet 801 is provided in the bearing housing 8 and distributed circumferentially along the bearing housing 8. The bearing housing air inlet 801 is connected between the fitting clearance between the bearing housing 8 and the main shaft 11 and the annular channel 802. A cover cavity 401 is provided in the cover 4 of the motor and has a main air outlet. A bearing housing air outlet 803 is provided in the bearing housing 8 extending axially. The bearing housing air outlet 803 is connected between the fitting clearance between the first radial air bearing 9 and the motor stator 3 at the end of the motor away from the volute 1 and the cover cavity 401. The second cooling air passage includes, in sequence, the air intake gap between the back of the compressor impeller 12 and the casing end face 201 of the casing 2 near the impeller 12, the fitting gap between the second radial air bearing 10 of the motor near the volute 1 and the main shaft 11, the fitting gap between the motor stator 3 and the main shaft 11, the fitting gap between the motor stator 3 and the first radial air bearing 9, and the bearing seat air outlet 803. The air intake gap is connected to the air outlet side of the impeller 12.

[0029] In the single-stage centrifugal air compressor provided in this application embodiment, the air cooling system cools the motor rotor components through a first cooling air path and a second cooling air path.

[0030] When the first cooling air path is working, the high-pressure gas generated by the rotation of the impeller 12 flows from the volute chamber 101 of the volute 1 into the cooling air channel 202 of the housing 2 through the air inlet of the housing 2, and then enters the annular channel 802 through the air outlet of the housing 2. Then, it flows through multiple bearing seat air inlets 801 to the mating gap between the bearing seat 8 and the motor main shaft 11. From this mating gap, it flows sequentially through the mating gap between the first radial air bearing 9 and the main shaft 11, and the mating gap between the first radial air bearing 9 and the motor stator 3. Finally, it converges into the cover cavity 401 through the bearing seat air outlet 803 and flows out from the main outlet of the cover cavity 401. This can realize the diversion of the high-pressure gas in the volute chamber 101 to the first radial air bearing 9 at the end of the motor away from the volute 1, and cool the rotor component at the end of the motor away from the volute 1 separately. When the second cooling air passage is working, the high-pressure gas generated by the rotation of the impeller 12 flows from the outlet side of the impeller 12 into the air inlet gap between the back of the impeller 12 and the end face 201 of the casing. Then, it flows sequentially through the fitting gap between the second radial air bearing 10 and the main shaft 11, the fitting gap between the motor stator 3 and the main shaft 11, and the fitting gap between the motor stator 3 and the first radial air bearing 9. Finally, it converges into the casing cavity 401 through the bearing seat outlet 803 and flows out from the main outlet of the casing cavity 401. This can guide the high-pressure gas on the back of the impeller 12 to the second radial air bearing 10 and the main shaft 11 near the end of the motor volute 1, and can cool the rotor components of the motor away from the end of the volute 1.

[0031] Therefore, this embodiment of the application draws out two airflows from the high-pressure gas generated by the rotation of the impeller 12. One airflow is introduced into the first cooling air path through the volute chamber 101 of the volute 1, which can cool the rotor components of the motor away from the volute 1 separately, thus preventing the airflow temperature at the rotor components away from the volute 1 from being too high and affecting the heat exchange effect. The other airflow is introduced into the second cooling air path through the outlet side of the impeller 12, which can cool the rotor components other than the end of the motor away from the volute 1. In this way, the first and second cooling air paths can cool different parts of the rotor components of the motor respectively, which can improve the cooling effect of the motor rotor components and ensure the performance of the motor. In addition, compared with an additional air intake scheme, the overall cost of the machine can be reduced.

[0032] In some embodiments, the single-stage centrifugal air compressor further includes a water cooling system, which includes: a housing end water cooling channel 204, which is opened at one end of the housing 2 near the volute 1, and the housing end water cooling channel 204 is provided with a water inlet 205 and a water outlet 207, and the water inlet 205 is connected to a water inlet connector 13; and a housing circumferential water cooling channel 208, which is opened along the circumference of the housing 2 and extends from one end near the volute 1 to one end away from the volute 1, the inlet of the housing circumferential water cooling channel 208 near the volute 1 is connected to the water outlet 207, and the outlet at the end away from the volute 1 is connected to a water outlet connector 14.

[0033] When the water cooling system is working, cooling water flows from the inlet connector 13 into the inlet hole 205, then flows into the water-cooling channel 204 at the end of the housing to cool the non-outgoing ends of the motor and the second radial air bearing 10. It then flows out through the outlet hole 207 and into the circumferential water-cooling channel 208 in the housing to cool the circumference of the motor, finally being discharged from the outlet connector 14. In this way, the water cooling system increases the heat exchange area for the non-outgoing ends of the motor and the second radial air bearing 10 through the water-cooling channel 204 at the end of the housing, improving the cooling effect on these two parts, reducing their temperature, increasing their service life, and improving the overall reliability of the machine. The water cooling system also increases the heat exchange area for the motor housing 2 and the motor stator 3 through the circumferential water-cooling channel 208, improving the cooling effect on the motor and thus increasing the motor's peak power and service life.

[0034] In addition, the circumferential water cooling channel 208 of the housing can also cool the airflow of the first cooling air path; the end water cooling channel 204 of the housing can also cool the airflow of the second cooling air path; thus, the gas temperature in the first cooling air path and the second cooling air path is lower, the heat exchange effect is more obvious, the cooling effect on the motor rotor components is better, and the rotor temperature and demagnetization risk can be effectively reduced to meet the high power operation requirements of the machine.

[0035] Optionally, the motor stator 3 and the housing 2 are sealed together with sealant, which can better transfer heat and improve the cooling effect.

[0036] In some embodiments, the water-cooling channel 204 at the end of the housing at least partially overlaps with the projection of the intake gap along the motor axis. This brings the water-cooling channel 204 closer to the intake gap, resulting in better cooling of the airflow in the intake gap and further reducing the gas temperature in the second cooling air path, thus improving the cooling effect.

[0037] The circumferential water-cooling channel 208 of the housing can be annular, spiral, or multiple strips arranged at intervals, as long as it can cool in the circumferential direction. In some embodiments, the circumferential water-cooling channel 208 and the housing cooling air channel 202 at least partially overlap in their radial projections along the motor. This results in a higher heat exchange efficiency between the circumferential water-cooling channel 208 and the housing cooling air channel 202, and a better cooling effect of the circumferential water-cooling channel 208 on the airflow in the housing cooling air channel 202, further reducing the gas temperature in the first cooling air path and improving the cooling effect.

[0038] In some embodiments, a heat exchange groove is provided on the end face 201 of the housing facing the air intake gap. The heat exchange groove can increase the contact area between the end face 201 of the housing and the airflow in the air intake gap, thereby improving the heat exchange efficiency between the cooling water in the water-cooling channel 204 at the end of the housing and the airflow in the air intake gap, reducing the gas temperature and improving the cooling effect. The heat exchange groove can be toothed, annular, wavy, etc.

[0039] In some embodiments, the end water-cooling channel 204 of the housing 2 covers the entire circumference of the end of the housing 2, and a cooling water partition 206 is provided in the end water-cooling channel 204 to seal and separate the water inlet 205 and the water outlet 207. In this way, the water inlet 205 and the water outlet 207 are located on both sides of the cooling water partition 206, and the cooling water partition 206 can separate the water inlet 205 and the water outlet 207. The water entering through the water inlet 205 must rotate once before flowing out through the water outlet 207, so that the cooling water can circulate fully in the end water-cooling channel 204 of the housing before flowing out, thereby optimizing the cooling effect on the non-lead-out end of the motor and the second radial air bearing 10.

[0040] Preferably, the cooling water partition 206 has a water flow guide surface on at least one side, which directs the water entering through the inlet hole 205 towards the outlet hole 207, further improving the circulation effect of the cooling water within the water-cooling channel 204 at the end of the casing and increasing cooling efficiency. Both sides of the cooling water partition 206 may have water flow guide surfaces, which are arc-shaped, providing a guiding function while reducing cooling water flow resistance. For example, as... Figure 3 As shown, the water inlet 205 and the water outlet 207 can both be set at the outer edge of the water cooling channel 204 at the end of the housing. The cooling water partition 206 is set radially along the housing 2, which is convenient for layout and processing. At this time, the width of the cooling water partition 206 along the circumference of the motor gradually increases from the position corresponding to the water inlet 205 to the inner edge of the water cooling channel 204 at the end of the housing, so that the two sides of the cooling water partition 206 form a V-shaped guide surface, which has a better guiding effect.

[0041] In some embodiments, the motor includes a thrust disk 6 disposed at the end of the first radial air bearing 9 away from the volute 1 (i.e., the end away from the impeller 12), with air-bearing thrust bearings 7 disposed at both ends of the thrust disk 6, and a thrust adjusting block 15 sleeved on the bearing housing 8, the thrust adjusting block 15 being sealed to the thrust disk 6 by a labyrinth seal structure. Figure 2As shown. In this way, the thrust disk 6 and the impeller 12 are respectively arranged at both ends of the main shaft 11. The thrust disk 6 can be used as an axial force balancing disk. The labyrinth seal structure between the thrust adjusting block 15 and the thrust disk 6 can block part of the airflow. This airflow can balance part of the axial force generated by the rotation of the impeller 12, thereby avoiding the problems of greater heat generation, increased size and weight of the whole machine, and increased cost caused by using a large-size thrust bearing. It can improve the service life of the bearing and reduce the cost of the machine.

[0042] In some embodiments, the first cooling air passage further includes the fitting clearance between the first air-bearing thrust bearing and the bearing housing 8, the fitting clearance of the labyrinth seal structure, the fitting clearance between the second air-bearing thrust bearing and the bearing back plate 5, and the fitting clearance between the bearing back plate 5 and the main shaft 11, which are connected in sequence; wherein, the fitting clearance between the first air-bearing thrust bearing and the bearing housing 8 is connected to the air inlet 801 of the bearing housing, and the fitting clearance between the bearing back plate 5 and the main shaft 11 is connected to the housing cavity 401; the first air-bearing thrust bearing is an air-bearing thrust bearing 7 located at the end of the thrust plate 6 near the bearing housing 8; the second air-bearing thrust bearing is an air-bearing thrust bearing 7 located at the end of the thrust plate 6 away from the bearing housing 8; the bearing back plate 5 is disposed at the end of the second air-bearing thrust bearing away from the thrust plate 6.

[0043] The cooling air in the first cooling air path is guided through the bearing housing inlet 801 to the space between the first radial air bearing 9 and the first air-bearing thrust bearing. The cooling air is then split. One stream cools the first radial air bearing 9 and then converges into the housing cavity 401 through the bearing housing outlet 803. The other stream flows sequentially through the fit clearance between the first air-bearing thrust bearing and the bearing housing 8, the fit clearance of the labyrinth seal structure, the fit clearance between the second air-bearing thrust bearing and the bearing back plate 5, and the fit clearance between the bearing back plate 5 and the main shaft 11, and finally converges into the housing cavity 401. This achieves cooling of the first air-bearing thrust bearing, the thrust plate 6, and the second air-bearing thrust bearing, improving the cooling effect and ensuring the motor operating temperature.

[0044] In some embodiments, the labyrinth seal structure includes: multiple ring-shaped sealing teeth disposed on the outer peripheral surface of the thrust disk 6, the ring-shaped sealing teeth being distributed along the axial direction of the thrust disk 6; and multiple sealing grooves formed on the inner peripheral surface of the thrust adjusting block 15, the sealing grooves being distributed along the axial direction of the thrust adjusting block 15, with the ring-shaped sealing teeth and sealing grooves corresponding to each other in a clearance fit. The clearance fit between the toothed multiple ring-shaped sealing teeth and the toothed multiple ring-shaped sealing grooves can block more airflow and achieve a better effect in balancing axial force. The positions of the ring-shaped sealing teeth and sealing grooves can be interchanged. The labyrinth seal structure can also adopt other forms, such as the combination of wavy protrusions and grooves.

[0045] In some embodiments, the housing cooling gas passage 202 includes multiple branch passages connected end to end, which are arranged circumferentially around the housing 2 and located near the outlet of the volute 1. In this way, the gas in the housing cooling gas passage 202 can be circumferentially reversed multiple times within the housing 2, achieving sufficient heat exchange with the circumferential water cooling passage 208, thereby reducing the gas temperature and improving the cooling effect.

[0046] The branch channels extend along the motor axis and can be selected as three. The gas undergoes three reversals within the housing 2, increasing the heat exchange area between the first cooling gas path and the circumferential water cooling channel 208 of the housing, and reducing the gas temperature.

[0047] In some embodiments, the casing 4 has a casing return air passage; the housing 2 has a housing return air passage 203, and the volute 1 has a volute return air passage; wherein the main outlet, casing return air passage, housing return air passage 203, volute return air passage, and compressor inlet are sequentially connected. In this way, all the cooling gas that converges into the casing cavity 401 flows from the main outlet through the casing return air passage, housing return air passage 203, and volute return air passage, and returns to the compressor inlet, which can recover and reuse part of the compressed gas, and at the same time facilitates the impeller 12 to pressurize the gas, saving impeller 12 power.

[0048] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details of the above application are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0049] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Unless otherwise defined, the technical or scientific terms used in the claims and description should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar words used in the patent application description and claims of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "an" or "a" and similar words do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" and similar words mean that the element or object preceding "comprising" or "including" encompasses the element or object listed following "comprising" or "including" and its equivalents, and do not exclude other elements or objects. The terms "connected," "coupled," or "linked" and similar words are not limited to physical or mechanical connections, nor are they limited to direct or indirect connections. Words such as “including,” “contains,” and “has” are open-ended words that mean “including but not limited to” and can be used interchangeably with them.

[0050] In this application, the terms "or" and "and / or" describe the relationship between related objects and indicate a non-exclusive inclusion. For example, "A and / or B" and "A or B" can include: only "A" exists, only "B" exists, and both "A" and "B" exist simultaneously, where "A" and "B" can be singular or plural. As another example, "A, B, and / or C" and "A, B, or C" can include: only "A" exists, only "B" exists, only "C" exists, both "A" and "B" exist simultaneously, both "A" and "C" exist simultaneously, both "B" and "C" exist simultaneously, and both "A", "B", and "C" exist simultaneously, where "A", "B", and "C" can be singular or plural. Furthermore, the symbol " / " in this application indicates an "or" relationship between the related objects before and after the symbol. In this application, the term "at least one A or B" has the same meaning as the aforementioned "A or B". The term "at least one A, B or C" has the same meaning as "A, B or C" above.

[0051] In the apparatus and equipment of this application, the components can be disassembled and / or reassembled. These disassemblies and / or reassemblies should be considered as equivalent solutions of this application.

[0052] The above description of the claimed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be applied within the widest scope consistent with the principles and novel features of this application.

[0053] The above description has been given for illustrative and descriptive purposes. Furthermore, this description is not intended to limit the embodiments of this application to the forms described herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A single-stage centrifugal air compressor, comprising a compressor and a motor; characterized in that, It also includes an air cooling system, which comprises a first cooling air passage and a second cooling air passage, wherein, The first cooling air path includes: A housing cooling air passage is provided in the housing of the motor and extends from one end near the volute of the compressor to the other end away from the volute. The housing cooling air passage has a housing air inlet that communicates with the volute chamber of the volute at the end near the volute and a housing air outlet at the end away from the volute. An annular channel is provided at the connection between the bearing seat and the housing at the end of the motor away from the volute, and the annular channel is connected to the air outlet of the housing; Multiple bearing housing air inlets are provided in the bearing housing and distributed circumferentially along the bearing housing. The bearing housing air inlets are connected between the mating clearance between the bearing housing and the spindle and the annular channel. A housing cavity is provided in the housing of the motor, and the housing cavity is provided with a main air outlet; An air vent is provided in the bearing housing, extending axially. The air vent connects the first radial air bearing at the end of the motor away from the volute and the mating clearance between the motor stator and the cavity of the casing. The motor includes a thrust plate disposed at the end of the first radial air bearing away from the volute. Air-bearing thrust bearings are respectively disposed at both ends of the thrust plate. A thrust adjustment block is disposed on the bearing housing and sleeved on the thrust plate. The thrust adjustment block and the thrust plate are sealed together by a labyrinth seal structure. The fitting clearances of the first air-bearing thrust bearing and the bearing housing, the fitting clearances of the labyrinth seal structure, the fitting clearances of the second air-bearing thrust bearing and the bearing back plate, and the fitting clearances of the bearing back plate and the main shaft are connected in sequence. Wherein, the fitting clearance between the first air-bearing thrust bearing and the bearing housing is connected to the air inlet of the bearing housing, and the fitting clearance between the bearing back plate and the main shaft is connected to the cavity of the cover. The first air-bearing thrust bearing is an air-bearing thrust bearing located at the end of the thrust plate near the bearing housing; the second air-bearing thrust bearing is an air-bearing thrust bearing located at the end of the thrust plate away from the bearing housing; the bearing back plate is disposed at the end of the second air-bearing thrust bearing away from the thrust plate. The labyrinth sealing structure includes: Multiple rings of annular sealing teeth are provided on the outer circumferential surface of the thrust disk, and the annular sealing teeth are distributed along the axial direction of the thrust disk; Multiple sealing grooves are formed on the inner circumferential surface of the thrust adjustment block, the sealing grooves are distributed along the axial direction of the thrust adjustment block, and the annular sealing teeth are in clearance fit with the sealing grooves in a one-to-one correspondence. The second cooling air path includes: The compressor's impeller back and the housing end face near the impeller's air intake gap are connected in sequence; the second radial air bearing of the motor near the volute end and the main shaft's fit gap are connected in sequence; the motor stator and the main shaft's fit gap are connected in sequence; the motor stator and the first radial air bearing's fit gap are connected in sequence; and the bearing seat's air outlet is connected in sequence. The air intake gap is connected to the impeller's air outlet side.

2. The single-stage centrifugal air compressor according to claim 1, characterized in that, It also includes a water cooling system, which comprises: A water-cooling channel is provided at the end of the housing near the volute. The water-cooling channel at the end of the housing is provided with a water inlet and a water outlet. The water inlet is connected to a water inlet connector. A circumferential water-cooling channel is formed along the circumference of the housing and extends from one end near the volute to the other end away from the volute. The inlet of the circumferential water-cooling channel near the volute is connected to the water outlet, and the outlet at the end away from the volute is connected to a water outlet connector.

3. The single-stage centrifugal air compressor according to claim 2, characterized in that, The water-cooling channel at the end of the housing at least partially overlaps with the projection of the air intake gap along the motor axis; And / or, the circumferential water cooling channel of the housing and the cooling air channel of the housing at least partially overlap along the radial direction of the motor.

4. The single-stage centrifugal air compressor according to claim 2, characterized in that, A heat exchange groove is provided on the end face of the casing facing the air intake gap.

5. The single-stage centrifugal air compressor according to claim 2, characterized in that, The water-cooling channel at the end of the housing is distributed throughout the entire circumference of the end of the housing, and a cooling water barrier is provided in the water-cooling channel at the end of the housing to seal and separate the water inlet and the water outlet. The cooling water isolation is provided with a water flow guide surface on at least one side to facilitate the flow of water entering through the inlet hole to the outlet hole.

6. The single-stage centrifugal air compressor according to claim 2, characterized in that, The casing cooling air passage includes multiple branch passages connected end to end, and the multiple branch passages are arranged along the circumference of the casing and located near the outlet of the volute.

7. The single-stage centrifugal air compressor according to claim 1, characterized in that, The cover is provided with a cover return air passage; the housing is provided with a housing return air passage; the volute is provided with a volute return air passage. The main air outlet, the cover return air channel, the housing return air channel, the volute return air channel, and the compressor inlet are connected in sequence.

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