Single-stage centrifugal air compressor

Abstract

The invention provides a single-stage centrifugal air compressor. 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 gas path comprises a shell cooling gas channel; an annular channel; a plurality of bearing seat air inlets; the housing cavity is provided with a main air outlet; the bearing seat air outlet hole is communicated between a fit clearance between a first radial air bearing, far away from the volute, of the motor and a motor stator and the housing cavity; the second cooling air path comprises an air inlet gap between the back of the impeller and the end face of the shell close to the impeller, a fit gap between a second radial air bearing of the motor close to the volute and the main shaft, a fit gap between the stator and the main shaft, a fit gap between the stator and the first radial air bearing and a bearing seat air outlet hole which are communicated in sequence; the air inlet gap communicates with the air outlet side of the impeller. The first cooling air path and the second cooling air path can cool rotor parts at different parts of the motor, so that the cooling effect on the rotor parts of the motor is improved, and the use performance of the motor is ensured.

Description

Technical Field

[0001] The present application relates to the technical field of air compressor cooling, and in particular to a single-stage centrifugal air compressor. Background Art

[0002] High-speed centrifugal air compressors are primarily used to boost the pressure of air in an air supply system. The high-speed rotation of the motor shaft directly drives the compressor's impeller, increasing the pressure. The motor shaft is supported at both ends by radial air bearings.

[0003] In the related art, the gas leaked from the back of the impeller cools the motor shaft, bearings and other rotor components in sequence along the axial direction. The cooling effect on the bearings of the motor far away from the impeller is poor, which affects the performance of the motor.

[0004] Secondly, the compressed gas leaking from the impeller back reaches a high temperature, which has a poor cooling effect on the rotor components. This can easily lead to rotor demagnetization due to high temperature, shortening the service life. The additional air bleed solution will increase the cost of the entire machine.

[0005] Furthermore, the non-outlet end of the ultra-high speed motor close to the impeller is the main high-temperature point. The relevant technology cools the motor through radial cooling water, resulting in low heat exchange efficiency at the end of the motor close to the impeller and poor cooling effect at the motor end, which affects the motor's service life and peak power.

[0006] Furthermore, high-speed centrifugal compressors generate significant axial forces. Related technologies use large thrust bearings to balance these forces, which results in increased heat generation in the thrust bearings, necessitating increased cooling airflow and reducing overall unit efficiency. Large thrust bearings also increase the overall size and weight of the compressor, driving up costs. Summary of the Invention

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

[0008] In order to achieve the above objectives, this application provides the following technical solutions:

[0009] A single-stage centrifugal air compressor includes a compressor and a motor; and further includes an air path cooling system, wherein the air path cooling system includes a first cooling air path and a second cooling air path, wherein:

[0010] The first cooling air path includes:

[0011] a casing cooling air passage, which is provided in the casing of the motor and extends from an end close to the volute of the compressor to an end away from the volute, wherein the end of the casing cooling air passage close to the volute is provided with a casing air inlet hole communicating with the volute chamber of the volute, and the end away from the volute is provided with a casing air outlet hole;

[0012] an annular channel, provided at the connection between the bearing seat of the motor away from the volute and the casing, the annular channel being in communication with the air outlet of the casing;

[0013] A plurality of bearing seat air inlet holes are provided in the bearing seat and distributed along the circumference of the bearing seat, wherein the bearing seat air inlet holes are connected between the fitting clearance between the bearing seat and the motor main shaft and the annular channel;

[0014] A housing cavity is provided in the housing of the motor, and the housing cavity is provided with a main air outlet;

[0015] A bearing seat air outlet is provided on the bearing seat and extends axially, wherein the bearing seat air outlet is connected to a first radial air bearing at one end of the motor away from the volute, a fitting gap between the motor stator and the housing cavity;

[0016] The second cooling air path includes:

[0017] The impeller back of the compressor and the air intake gap of the casing end face close to the impeller, the fitting gap between the second radial air bearing of the motor close to one end of the volute and the main shaft, the fitting gap between the stator and the main shaft, the fitting gap between the stator and the first radial air bearing, and the air outlet of the bearing seat are connected in sequence, and the air intake gap is connected to the air outlet side of the impeller.

[0018] Optionally, the above-mentioned single-stage centrifugal air compressor further includes a water cooling system, and the water cooling system includes:

[0019] A water cooling channel at the end of the casing is opened at one end of the casing close to the volute, and the water cooling channel at the end of the casing is provided with a water inlet and a water outlet, and the water inlet is connected to a water inlet joint;

[0020] The casing circumferential water cooling channel is opened in the casing along the circumference of the casing and extends from an end close to the volute to an end away from the volute. The inlet of the casing circumferential water cooling channel close to the end of the volute is connected to the water outlet, and the outlet at the end away from the volute is connected to a water outlet joint.

[0021] 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 axial direction of the motor at least partially overlap;

[0022] And / or, the projection of the casing circumferential water cooling channel and the casing cooling air channel along the radial direction of the motor at least partially overlaps.

[0023] Optionally, in the above-mentioned single-stage centrifugal air compressor, a heat exchange groove is provided at a position of the casing end surface facing the air intake gap.

[0024] 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 partition is provided in the water-cooling channel at the end of the casing to seal and separate the water inlet and the water outlet;

[0025] At least one side of the cooling water partition is provided with a water flow guide surface for promoting the water entering the water inlet to flow toward the water outlet.

[0026] Optionally, in the above-mentioned single-stage centrifugal air compressor, the motor includes a thrust plate arranged at one end of the first radial air bearing away from the volute, and air-floating thrust bearings are respectively provided at both ends of the thrust plate. A thrust adjustment block is provided on the bearing seat and is sleeved on the thrust plate. The thrust adjustment block and the thrust plate are sealed by a labyrinth sealing structure.

[0027] Optionally, in the above-mentioned single-stage centrifugal air compressor, the first cooling air path further comprises:

[0028] The matching clearance between the first air-floating thrust bearing and the bearing seat, the matching clearance between the labyrinth seal structure, the matching clearance between the second air-floating thrust bearing and the bearing back plate, and the matching clearance between the bearing back plate and the main shaft are connected in sequence;

[0029] The fitting clearance between the first air-floating thrust bearing and the bearing seat is communicated with the air inlet hole of the bearing seat, and the fitting clearance between the bearing back plate and the main shaft is communicated with the housing cavity;

[0030] The first air-floating thrust bearing is an air-floating thrust bearing located at one end of the thrust plate close to the bearing seat; the second air-floating thrust bearing is an air-floating thrust bearing located at one end of the thrust plate away from the bearing seat; the bearing back plate is arranged at the end of the second air-floating thrust bearing away from the thrust plate.

[0031] Optionally, in the above-mentioned single-stage centrifugal air compressor, the labyrinth seal structure includes:

[0032] A plurality of ring-shaped sealing teeth are provided on the outer peripheral surface of the thrust plate, and the ring-shaped sealing teeth are distributed along the axial direction of the thrust plate;

[0033] A plurality of sealing grooves are provided on the inner circumference of the thrust adjustment block. The sealing grooves are distributed along the axial direction of the thrust adjustment block. The annular sealing teeth are clearance-matched with the sealing grooves in a one-to-one correspondence.

[0034] Optionally, in the above-mentioned single-stage centrifugal air compressor, the casing cooling air channel includes a plurality of branch channels connected end to end in sequence, and the plurality of branch channels are arranged along the circumference of the casing and are provided close to the outlet of the volute.

[0035] Optionally, in the above-mentioned single-stage centrifugal air compressor, the cover is provided with a cover air return channel; the casing is provided with a casing air return channel, and the volute is provided with a volute air return channel;

[0036] Wherein, the main air outlet, the cover air return channel, the casing air return channel, the volute air return channel and the compressor inlet are connected in sequence.

[0037] In the single-stage centrifugal air compressor provided in the present application, the air path cooling system cools the motor rotor components through the first cooling air path and the second cooling air path.

[0038] When the first cooling air path is working, the high-pressure gas generated by the rotation and work of the impeller flows from the volute chamber of the volute through the air inlet hole of the casing into the cooling air channel of the casing, and enters the annular channel through the air outlet hole of the casing, and then flows through multiple bearing seat air inlet holes to the fitting gap between the bearing seat and the motor main shaft, and from this fitting gap it flows in turn through the fitting gap between the first radial air floating bearing and the main shaft, and the fitting gap between the first radial air floating bearing and the motor stator, and finally converges into the cover cavity through the air outlet hole of the bearing seat, and flows out from the total air outlet of the cover cavity; the high-pressure gas in the volute chamber can be diverted to the first radial air floating bearing at the end of the motor away from the volute, so as to cool the rotor component of the motor away from the end of the volute.

[0039] When the second cooling air path is working, the high-pressure gas generated by the rotation of the impeller 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, and then flows through the fitting gap between the second radial air floating bearing and the main shaft, the fitting gap between the stator and the main shaft, and the fitting gap between the stator and the first radial air floating bearing in turn, and finally converges into the cover cavity through the air outlet hole of the bearing seat and flows out from the total air outlet of the cover cavity. The high-pressure gas on the back of the impeller can be diverted to the second radial air floating bearing and the main shaft near the end of the volute of the motor, and the rotor components of the motor other than the end away from the volute can be cooled.

[0040] It can be seen that the present application draws out two airflows from the high-pressure gas generated by the rotation of the impeller. One airflow is introduced into the first cooling air path from the volute chamber of the volute, which can cool the rotor component of the motor away from the volute separately, thus preventing the airflow temperature from being too high at the rotor component of the motor away from the volute, thereby affecting the heat exchange effect. The other airflow is introduced into the second cooling air path from the outlet side of the impeller, which can cool the rotor components of the motor other than the end away from the volute. In this way, the first cooling air path and the second cooling air path can cool the rotor components of different parts of the motor respectively, thereby improving the cooling effect of the motor rotor components and ensuring the performance of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following describes the drawings required for use in the embodiments or the description of the prior art. The drawings described below are merely embodiments of the present application. For those skilled in the art, other drawings can be obtained based on the provided drawings without inventive effort.

[0042] Figure 1 A schematic structural diagram of an exemplary single-stage centrifugal air compressor consistent with some embodiments of the present application is shown;

[0043] Figure 2 Shown Figure 1 A partial enlarged view of part A;

[0044] Figure 3 A schematic cross-sectional structure diagram of a water-cooling channel at the end of a casing of an exemplary single-stage centrifugal air compressor consistent with some embodiments of the present application is shown.

[0045] above Figure 1-Figure 3 middle:

[0046] 1-volute; 101-volute chamber; 2-casing; 201-casing end face; 202-casing cooling air channel; 203-casing return air channel; 204-casing end water-cooling channel; 205-water inlet; 206-cooling water partition; 207-water outlet; 208-casing circumferential water-cooling channel; 3-stator; 4-cover; 401-casing cavity; 5-bearing back plate; 6-thrust plate; 7-air-floating thrust bearing; 8-bearing seat; 801-bearing seat air inlet; 802-annular channel; 803-bearing seat air outlet; 9-first radial air-floating bearing; 10-second radial air-floating bearing; 11-main shaft; 12-impeller; 13-water inlet joint; 14-water outlet joint; 15-thrust adjustment block. DETAILED DESCRIPTION

[0047] The following describes the embodiments of the present application. It should be noted that, in the specific description of these embodiments, in order to provide a concise description, this specification cannot provide a detailed description of all the features of the actual embodiments. It should be understood that in the actual implementation of any embodiment, in order to achieve specific goals, changes from one embodiment to another will occur. In addition, it is also understood that although the efforts made in this development process may be complex and lengthy, for ordinary technicians in the field related to the content of this application, some changes in design, manufacturing or production based on the technical content disclosed in this application are just conventional technical means and should not be understood as the content of this application being insufficient.

[0048] like Figure 1-Figure 3As shown, the single-stage centrifugal air compressor provided in the embodiments of the present application includes a compressor and a motor. Specifically, the compressor includes an impeller 12 and a volute 1 having a volute 101. The motor includes a housing 2, a stator 3, a main shaft 11, a cover 4, an air-floating thrust bearing 7, a bearing seat 8, a first radial air-floating bearing 9, and a second radial air-floating bearing 10.

[0049] The single-stage centrifugal air compressor provided in the embodiment of the present application further includes an air path cooling system, the air path cooling system including a first cooling air path and a second cooling air path;

[0050] Among them, the first cooling air path includes: a casing cooling air channel 202, which is opened in the casing 2 of the motor and extends from the end of the volute 1 close to the compressor to the end away from the volute 1, and the casing cooling air channel 202 is provided with a casing 2 air inlet communicating with the volute chamber 101 of the volute 1 at the end close to the volute 1, and an casing 2 air outlet at the end away from the volute 1; an annular channel 802, which is provided at the connection between the bearing seat 8 and the casing 2 at the end of the motor away from the volute 1, and the annular channel 802 is connected to the casing 2 air outlet; multiple bearing seat inlets The air holes 801 are provided in the bearing seat 8 and are distributed along the circumference of the bearing seat 8. The bearing seat air inlet holes 801 are connected between the fitting clearance between the bearing seat 8 and the motor main shaft 11 and the annular channel 802. The housing cavity 401 is provided in the housing 4 of the motor. The housing cavity 401 is provided with a main air outlet. The bearing seat air outlet holes 803 are provided in the bearing seat 8 along the axial direction. The bearing seat air outlet holes 803 are connected between the fitting clearance between the first radial air bearing 9 at the end of the motor away from the volute 1 and the motor stator 3 and the housing cavity 401.

[0051] The second cooling air path includes the air intake gap between the back of the impeller 12 of the compressor 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 one end of the volute 1 and the main shaft 11, the fitting gap between the stator 3 and the main shaft 11, the fitting gap between the stator 3 and the first radial air bearing 9, and the bearing seat air outlet 803, which are connected in sequence. The air intake gap is connected to the air outlet side of the impeller 12.

[0052] In the single-stage centrifugal air compressor provided in the embodiment of the present application, the air path cooling system cools the motor rotor components through the first cooling air path and the second cooling air path.

[0053] When the first cooling air path is working, the high-pressure gas generated by the rotation and work of the impeller 12 flows from the volute chamber 101 of the volute 1 through the air inlet hole of the casing 2 into the casing cooling air channel 202, and enters the annular channel 802 through the air outlet hole of the casing 2, and then flows through multiple bearing seat air inlet holes 801 to the fitting gap between the bearing seat 8 and the motor main shaft 11, and from this fitting gap flows in turn through the fitting gap between the first radial air floating bearing 9 and the main shaft 11, and the fitting gap between the first radial air floating bearing 9 and the motor stator 3, and finally converges into the casing cavity 401 through the bearing seat air outlet hole 803, and flows out from the total air outlet of the casing cavity 401; the high-pressure gas in the volute chamber 101 can be diverted to the first radial air floating bearing 9 at the end of the motor away from the volute 1, so as to cool the rotor component of the motor away from the volute 1 separately;

[0054] When the second cooling air path is working, the high-pressure gas generated by the rotation and work 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, and then flows through the fitting gap between the second radial air floating bearing 10 and the main shaft 11, the fitting gap between the stator 3 and the main shaft 11, and the fitting gap between the stator 3 and the first radial air floating bearing 9 in turn, and finally converges into the casing cavity 401 through the bearing seat outlet hole 803, and flows out from the total outlet of the casing cavity 401; the high-pressure gas on the back of the impeller 12 can be diverted to the second radial air floating bearing 10 and the main shaft 11 at the end of the motor close to the volute 1, and the rotor components of the motor other than the end away from the volute 1 can be cooled.

[0055] It can be seen that the embodiment of the present application draws out two airflows from the high-pressure gas generated by the rotation and work of the impeller 12; one airflow is introduced into the first cooling air path from the volute chamber 101 of the volute 1, which can cool the rotor component of the motor away from the volute 1 separately, and can avoid the airflow temperature flowing to the rotor component of the motor away from the volute 1 being too high and affecting the heat exchange effect; the other airflow is introduced into the second cooling air path from the air outlet side of the impeller 12, and can cool the rotor components of the motor other than the end away from the volute 1. In this way, the first cooling air path and the second cooling air path can cool the rotor components of different parts 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 the additional air introduction solution, the cost of the whole machine can be reduced.

[0056] In some embodiments, the single-stage centrifugal air compressor also includes a water cooling system, which includes: a casing end water cooling channel 204, which is opened at the end of the casing 2 close to the volute 1, and the casing 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 the water inlet joint 13; a casing circumferential water cooling channel 208, which is opened in the casing 2 along the circumference of the casing 2 and extends from the end close to the volute 1 to the end away from the volute 1, the inlet of the casing circumferential water cooling channel 208 close to the volute 1 is connected to the water outlet 207, and the outlet at the end away from the volute 1 is connected to the water outlet joint 14.

[0057] When the water cooling system is operating, cooling water flows from the water inlet connector 13 to the water inlet hole 205, then flows into the housing end water cooling channel 204 to cool the non-outlet end of the motor and the second radial air bearing 10. It then flows out through the water outlet hole 207 and flows into the housing circumferential water cooling channel 208 to cool the circumference of the motor, and finally is discharged from the water outlet connector 14. In this way, the water cooling system increases the cooling and heat exchange area for the non-outlet end of the motor and the second radial air bearing 10 through the housing end water cooling channel 204, improving the cooling effect on the non-outlet end of the motor and the second radial air bearing 10, reducing their temperature, increasing their service life, and improving the operational reliability of the entire machine. The water cooling system increases the cooling and heat exchange area for the motor housing 2 and stator 3 through the housing circumferential water cooling channel 208, improving the cooling effect on the motor, and thereby increasing the peak power and service life of the motor.

[0058] In addition, the circumferential water-cooling channel 208 of the casing can also cool the airflow of the first cooling air path; the water-cooling channel 204 at the end of the casing can also cool the airflow of the second cooling air path; the gas temperature in the first cooling air path and the second cooling air path is lower, the heat exchange effect is more obvious, and the cooling effect on the motor rotor components is better, which can effectively reduce the rotor temperature and demagnetization risk, and meet the high-power operation requirements of the machine.

[0059] Optionally, the motor stator 3 and the housing 2 are sealed and connected by sealant, which can better transfer heat and improve the cooling effect.

[0060] In some embodiments, the housing end water-cooling channel 204 at least partially overlaps the projection of the air intake gap along the motor axis. This allows the housing end water-cooling channel 204 to be closer to the air intake gap, providing a better cooling effect on the airflow in the air intake gap, further reducing the gas temperature in the second cooling air path and improving the cooling effect.

[0061] The casing circumferential water-cooling channels 208 can be annular, spiral, or multiple strips arranged at intervals, as long as they can provide cooling in the circumferential direction. In some embodiments, the casing circumferential water-cooling channels 208 and the casing cooling air channels 202, projected along the motor's radial direction, at least partially overlap. This enhances the heat exchange between the casing circumferential water-cooling channels 208 and the casing cooling air channels 202, and the casing circumferential water-cooling channels 208 effectively cool the airflow in the casing cooling air channels 202, further reducing the gas temperature in the first cooling air path and improving the cooling effect.

[0062] In some embodiments, a heat exchange groove is provided on the housing end surface 201 facing the air intake gap. The heat exchange groove increases the contact area between the housing end surface 201 and the airflow in the air intake gap, thereby improving the heat exchange efficiency between the cooling water in the housing end water cooling channel 204 and the airflow in the air intake gap, thereby reducing the air temperature and improving the cooling effect. The heat exchange groove may have a toothed, annular, or wavy shape, etc.

[0063] In some embodiments, the casing end water-cooling channel 204 extends along the entire circumference of the end of the casing 2. A cooling water partition 206 is provided within the casing end water-cooling channel 204, sealingly separating the water inlet 205 from the water outlet 207. Thus, the water inlet 205 and the water outlet 207 are located on either side of the cooling water partition 206. The cooling water partition 206 separates the water inlet 205 from the water outlet 207. Water entering the water inlet 205 must circulate once before exiting the water outlet 207. This ensures that the cooling water fully circulates within the casing end water-cooling channel 204 before exiting, optimizing the cooling effect on the non-outlet end of the motor and the second radial air bearing 10.

[0064] Preferably, at least one side of the cooling water partition 206 is provided with a water flow guide surface that encourages water entering the water inlet 205 to flow toward the water outlet 207, further improving the circulation effect of the cooling water in the water cooling channel 204 at the end of the housing and improving the cooling efficiency. Water flow guide surfaces can be provided on both sides of the cooling water partition 206. The water flow guide surfaces are arc-shaped, which have a guiding effect and reduce the flow resistance of the cooling water. For example, Figure 3 As shown, the water inlet hole 205 and the water outlet hole 207 can both be set at the outer ring edge of the water cooling channel 204 at the end of the casing, and the cooling water partition 206 is set along the radial direction of the casing 2 to facilitate 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 hole 205 to the inner ring of the water cooling channel 204 at the end of the casing, so that the two sides of the cooling water partition 206 have an eight-shaped guide surface, which has a better diversion effect.

[0065] In some embodiments, the motor includes a thrust plate 6 arranged at the end of the first radial air bearing 9 away from the volute 1 (that is, the end away from the impeller 12), and air bearings 7 are respectively provided at both ends of the thrust plate 6. A thrust adjustment block 15 is provided on the bearing seat 8 and is outer-mounted on the thrust plate 6. The thrust adjustment block 15 and the thrust plate 6 are sealed by a labyrinth sealing structure. Figure 2 As shown. In this way, the thrust plate 6 and the impeller 12 are respectively arranged at both ends of the main shaft 11. The thrust plate 6 can be used as an axial force balancing plate. The labyrinth seal structure between the thrust adjustment block 15 and the thrust plate 6 can block part of the airflow, which can balance part of the axial force generated by the rotation of the impeller 12. This can avoid the problems of greater heat generation, increased volume and weight of the entire machine, and increased cost caused by the use of large-sized thrust bearings, thereby increasing the service life of the bearings and reducing machine costs.

[0066] In some embodiments, the first cooling air path also includes the fitting clearance of the first air-floating thrust bearing and the bearing seat 8, the fitting clearance of the labyrinth seal structure, the fitting clearance of the second air-floating thrust bearing and the bearing back plate 5, and the fitting clearance of the bearing back plate 5 and the main shaft 11, which are connected in sequence; wherein, the fitting clearance of the first air-floating thrust bearing and the bearing seat 8 is connected to the bearing seat air inlet hole 801, and the fitting clearance of the bearing back plate 5 and the main shaft 11 is connected to the cover cavity 401; the first air-floating thrust bearing is an air-floating thrust bearing 7 located at one end of the thrust plate 6 close to the bearing seat 8; the second air-floating thrust bearing is an air-floating thrust bearing 7 located at one end of the thrust plate 6 away from the bearing seat 8; the bearing back plate 5 is arranged at the end of the second air-floating thrust bearing away from the thrust plate 6.

[0067] The cooling air in the first cooling air path is guided between the first radial air-floating bearing 9 and the first air-floating thrust bearing through the bearing seat air inlet hole 801; the cooling air is split, and one stream cools the first radial air-floating bearing 9 and then converges into the cover cavity 401 through the bearing seat air outlet hole 803; the other stream flows through the fitting clearance between the first air-floating thrust bearing and the bearing seat 8, the fitting clearance of the labyrinth seal structure, the fitting clearance between the second air-floating thrust bearing and the bearing back plate 5, and the fitting clearance between the bearing back plate 5 and the main shaft 11, and finally converges into the cover cavity 401, thereby cooling the first air-floating thrust bearing, the thrust plate 6 and the second air-floating thrust bearing, improving the cooling effect and ensuring the operating temperature of the motor.

[0068] In some embodiments, the labyrinth seal structure includes: multiple rings of annular sealing teeth disposed on the outer circumference of the thrust disc 6, distributed axially along the thrust disc 6; and multiple rings of sealing grooves disposed on the inner circumference of the thrust adjustment block 15, distributed axially along the thrust adjustment block 15. The rings of sealing teeth and the sealing grooves have a one-to-one clearance fit. The clearance fit between the multiple rings of tooth-shaped annular sealing teeth and the multiple rings of tooth-shaped sealing grooves can block more airflow and effectively balance axial forces. The positions of the rings of sealing teeth and the sealing grooves are interchangeable. The labyrinth seal structure can also adopt other forms, such as a combination of wavy protrusions and grooves.

[0069] In some embodiments, the casing cooling air passage 202 includes multiple branch passages connected end-to-end. The multiple branch passages are arranged circumferentially along the casing 2 and located near the outlet of the volute 1. In this way, the gas in the casing cooling air passage 202 can make multiple turns within the casing 2, achieving sufficient heat exchange with the casing circumferential water-cooling passage 208, thereby reducing the gas temperature and improving the cooling effect.

[0070] The branch channels extend along the axial direction of the motor and may be three. The gas makes three turns in the casing 2, thereby increasing the heat exchange area between the first cooling gas path and the casing circumferential water cooling channel 208 and reducing the gas temperature.

[0071] In some embodiments, the housing 4 is provided with a housing return air passage; the housing 2 is provided with a housing return air passage 203; and the volute 1 is provided with a volute return air passage. The main air outlet, the housing return air passage, the housing return air passage 203, the volute return air passage, and the compressor inlet are sequentially connected. In this way, all cooling gas that converges into the housing cavity 401 flows from the main air outlet through the housing return air passage, the housing return air passage 203, the volute return air passage, and back to the compressor inlet, allowing for the recycling of this compressed gas. This also facilitates the impeller 12 in boosting the gas pressure, saving power for the impeller 12.

[0072] The basic principles of the present application have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, and effects mentioned in this application are merely illustrative and not restrictive, and it should not be assumed that these advantages, strengths, and effects are required of each embodiment of this application. In addition, the specific details of the above application are merely illustrative and for ease of understanding, and are not restrictive. The above details do not limit this application to being implemented by adopting the above specific details.

[0073] The block diagrams of the devices, apparatuses, equipment, and systems described in this application are intended to be illustrative examples only 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 will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems may be connected, arranged, or configured in any manner. Unless otherwise defined, technical or scientific terms used in the claims and specification should have the ordinary meanings understood by persons of ordinary skill in the art to which this application relates. The terms "first," "second," and similar expressions used in this patent specification and claims do not denote any order, quantity, or importance; they are simply used to distinguish between different components. Terms such as "a" or "an" do not denote a limitation of quantity, but rather the presence of at least one. Terms such as "include" or "comprising" mean that the elements or objects preceding the term "include" or "comprising" include the elements or objects listed after the term and their equivalents, and do not exclude other elements or objects. Terms such as "connected," "coupled," or "connected" are not limited to physical or mechanical connections, nor are they limited to direct or indirect connections. Words such as "including," "comprising," "having," etc. are open-ended words meaning "including but not limited to," and are used interchangeably therewith.

[0074] In this application, the terms "or" and "and / or" describe the association relationship between related objects and represent a non-exclusive inclusion. For example, "A and / or B" and "A or B" may include: only "A" exists, only "B" exists, and "A" and "B" exist at the same time, where "A" and "B" can be singular or plural. For another example, "A, B and / or C" and "A, B or C" may include: only "A" exists, only "B" exists, only "C" exists, "A" and "B" exist at the same time, "A" and "C" exist at the same time, "B" and "C" exist at the same time, and "A", "B" and "C" exist at the same time, where "A", "B" and "C" can be singular or plural. In addition, the symbol " / " in this application indicates that there is 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 above-mentioned "A or B". The term "at least one A, B or C" has the same meaning as the above-mentioned "A, B or C".

[0075] In the apparatus and device of the present application, each component can be decomposed and / or reassembled. Such decomposition and / or reassembly shall be regarded as equivalent solutions of the present application.

[0076] The above description of the claimed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features of the present application.

[0077] The above description has been provided for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the present application to the form in which it is applied. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, 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 path cooling system, the air path cooling system includes a first cooling air path and a second cooling air path, wherein, The first cooling air path includes: a casing cooling air passage, which is provided in the casing of the motor and extends from an end close to the volute of the compressor to an end away from the volute, wherein the end of the casing cooling air passage close to the volute is provided with a casing air inlet hole communicating with the volute chamber of the volute, and the end away from the volute is provided with a casing air outlet hole; an annular channel, provided at the connection between the bearing seat of the motor away from the volute and the casing, the annular channel being in communication with the air outlet of the casing; A plurality of bearing seat air inlet holes are provided in the bearing seat and distributed along the circumference of the bearing seat, wherein the bearing seat air inlet holes are connected between the fitting clearance between the bearing seat and the motor main shaft 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; A bearing seat air outlet is provided on the bearing seat and extends axially, wherein the bearing seat air outlet is connected to a first radial air bearing at one end of the motor away from the volute, a fitting gap between the motor stator and the housing cavity; The second cooling air path includes: The impeller back of the compressor and the air intake gap of the casing end face close to the impeller, the fitting gap between the second radial air bearing of the motor close to one end of the volute and the main shaft, the fitting gap between the stator and the main shaft, the fitting gap between the stator and the first radial air bearing, and the air outlet of the bearing seat are connected in sequence, and the air intake gap is connected to the air outlet side of the impeller.

2. The single-stage centrifugal air compressor according to claim 1, characterized in that: It also includes a water cooling system, which includes: A water cooling channel at the end of the casing is opened at one end of the casing close to the volute, and the water cooling channel at the end of the casing is provided with a water inlet and a water outlet, and the water inlet is connected to a water inlet joint; The casing circumferential water cooling channel is opened in the casing along the circumference of the casing and extends from an end close to the volute to an end away from the volute. The inlet of the casing circumferential water cooling channel close to the end of the volute is connected to the water outlet, and the outlet at the end away from the volute is connected to a water outlet joint.

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

4. The single-stage centrifugal air compressor according to claim 2, characterized in that: A heat exchange groove is provided on the end surface 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 casing is distributed over the entire circumference of the end of the casing, and a cooling water partition is provided in the water cooling channel at the end of the casing to seal and separate the water inlet and the water outlet; At least one side of the cooling water partition is provided with a water flow guide surface for promoting the water entering the water inlet to flow toward the water outlet.

6. The single-stage centrifugal air compressor according to claim 1, characterized in that: The motor includes a thrust plate arranged at one end of the first radial air bearing away from the volute, and air bearings are respectively provided at both ends of the thrust plate. A thrust adjustment block is provided on the bearing seat and is sleeved on the thrust plate. The thrust adjustment block and the thrust plate are sealed by a labyrinth sealing structure.

7. The single-stage centrifugal air compressor according to claim 6, characterized in that: The first cooling air path further comprises: The matching clearance between the first air-floating thrust bearing and the bearing seat, the matching clearance between the labyrinth seal structure, the matching clearance between the second air-floating thrust bearing and the bearing back plate, and the matching clearance between the bearing back plate and the main shaft are connected in sequence; The fitting clearance between the first air-floating thrust bearing and the bearing seat is communicated with the air inlet hole of the bearing seat, and the fitting clearance between the bearing back plate and the main shaft is communicated with the housing cavity; The first air-floating thrust bearing is an air-floating thrust bearing located at one end of the thrust plate close to the bearing seat; the second air-floating thrust bearing is an air-floating thrust bearing located at one end of the thrust plate away from the bearing seat; the bearing back plate is arranged at the end of the second air-floating thrust bearing away from the thrust plate.

8. The single-stage centrifugal air compressor according to claim 6, characterized in that: The labyrinth sealing structure comprises: A plurality of ring-shaped sealing teeth are provided on the outer peripheral surface of the thrust plate, and the ring-shaped sealing teeth are distributed along the axial direction of the thrust plate; A plurality of sealing grooves are provided on the inner circumference of the thrust adjustment block. The sealing grooves are distributed along the axial direction of the thrust adjustment block. The annular sealing teeth are clearance-matched with the sealing grooves in a one-to-one correspondence.

9. The single-stage centrifugal air compressor according to claim 2, characterized in that: The casing cooling air passage includes a plurality of branch passages that are sequentially connected end to end. The plurality of branch passages are arranged along the circumference of the casing and are disposed close to the outlet of the volute.

10. The single-stage centrifugal air compressor according to claim 1, characterized in that: The cover is provided with a cover air return channel; the casing is provided with an organic casing air return channel, and the volute is provided with a volute air return channel; Wherein, the main air outlet, the cover air return channel, the casing air return channel, the volute air return channel and the compressor inlet are connected in sequence.

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